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Sample records for riveted lap joints

  1. Experimental characterization and numerical simulation of riveted lap-shear joints using Rivet Element

    Science.gov (United States)

    Vivio, Francesco; Fanelli, Pierluigi; Ferracci, Michele

    2018-03-01

    In aeronautical and automotive industries the use of rivets for applications requiring several joining points is now very common. In spite of a very simple shape, a riveted junction has many contact surfaces and stress concentrations that make the local stiffness very difficult to be calculated. To overcome this difficulty, commonly finite element models with very dense meshes are performed for single joint analysis because the accuracy is crucial for a correct structural analysis. Anyhow, when several riveted joints are present, the simulation becomes computationally too heavy and usually significant restrictions to joint modelling are introduced, sacrificing the accuracy of local stiffness evaluation. In this paper, we tested the accuracy of a rivet finite element presented in previous works by the authors. The structural behaviour of a lap joint specimen with a rivet joining is simulated numerically and compared to experimental measurements. The Rivet Element, based on a closed-form solution of a reference theoretical model of the rivet joint, simulates local and overall stiffness of the junction combining high accuracy with low degrees of freedom contribution. In this paper the Rivet Element performances are compared to that of a FE non-linear model of the rivet, built with solid elements and dense mesh, and to experimental data. The promising results reported allow to consider the Rivet Element able to simulate, with a great accuracy, actual structures with several rivet connections.

  2. Riveted Lap Joints in Aircraft Fuselage Design, Analysis and Properties

    CERN Document Server

    Skorupa, Andrzej

    2012-01-01

    Fatigue of the pressurized fuselages of transport aircraft is a significant problem all builders and users of aircraft have to cope with for reasons associated with assuring a sufficient lifetime and safety, and formulating adequate inspection procedures. These aspects are all addressed in various formal protocols for creating and maintaining airworthiness, including damage tolerance considerations. In most transport aircraft, fatigue occurs in lap joints, sometimes leading to circumstances that threaten safety in critical ways. The problem of fatigue of lap joints has been considerably enlarged by the goal of extending aircraft lifetimes. Fatigue of riveted lap joints between aluminium alloy sheets, typical of the pressurized aircraft fuselage, is the major topic of the present book. The richly illustrated and well-structured chapters treat subjects such as: structural design solutions and loading conditions for fuselage skin joints; relevance of laboratory test results for simple lap joint specimens to rive...

  3. A multi-feature integration method for fatigue crack detection and crack length estimation in riveted lap joints using Lamb waves

    Data.gov (United States)

    National Aeronautics and Space Administration — This paper presents an experimental study of damage detection and quantification in riveted lap joints. Embedded lead zirconate titanate piezoelectric (PZT) ceramic...

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

    Science.gov (United States)

    Okafor, A. C.; Natarajan, S.

    2007-03-01

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

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

    International Nuclear Information System (INIS)

    Okafor, A. C.; Natarajan, S.

    2007-01-01

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

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

    Science.gov (United States)

    He, Jingjing; Wang, Dengjiang; Zhang, Weifang

    2015-03-01

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

  7. Influence of aluminium sheet surface modification on the self-piercing riveting process and the joint static lap shear strength

    OpenAIRE

    Li, Dezhi

    2017-01-01

    Self-piercing riveting (SPR) has been widely used in automotive as one of the major joining technologies for aluminium structures due to its advantages over some of the more traditional joining technologies. Research has shown that friction is a very important factor that influences both the riveting process and the joint strength for SPR, but these influences have not been fully understood. In this paper, AA5754 sheets with different surface textures, such as original with solid wax, hot wat...

  8. Computed vs. conventional radiography for detecting fatigue cracks in riveted lap joints of aeronautical grade hybrid fiber-metal laminate Glare

    International Nuclear Information System (INIS)

    Tarpani, J.R.; Hideki Shinohara, A.; Da Silva, R.R.; Do Val Lacerda, N.

    2007-01-01

    This study aimed at assessing the capability of three different radiographic approaches (two computed or digital, and one conventional or analogous) for imaging fatigue cracks in riveted lap joints of composite fiber-metal laminate Glare. These structural joints are unique in the sense that fatigue cracks develop mainly at the faying surfaces of Glare sheets, so that visual detection is largely prevented and nondestructive inspection becomes mandatory. For this purpose, a round-robin programme comprising several industrial and research centers that employ X-ray radiography routinely to inspect high-demanding equipments, components and structures was conducted. (authors)

  9. A multi-feature integration method for fatigue crack detection and crack length estimation in riveted lap joints using Lamb waves

    Science.gov (United States)

    He, Jingjing; Guan, Xuefei; Peng, Tishun; Liu, Yongming; Saxena, Abhinav; Celaya, Jose; Goebel, Kai

    2013-10-01

    This paper presents an experimental study of damage detection and quantification in riveted lap joints. Embedded lead zirconate titanate piezoelectric (PZT) ceramic wafer-type sensors are employed to perform in situ non-destructive evaluation (NDE) during fatigue cyclical loading. PZT wafers are used to monitor the wave reflection from the boundaries of the fatigue crack at the edge of bolt joints. The group velocity of the guided wave is calculated to select a proper time window in which the received signal contains the damage information. It is found that the fatigue crack lengths are correlated with three main features of the signal, i.e., correlation coefficient, amplitude change, and phase change. It was also observed that a single feature cannot be used to quantify the damage among different specimens since a considerable variability was observed in the response from different specimens. A multi-feature integration method based on a second-order multivariate regression analysis is proposed for the prediction of fatigue crack lengths using sensor measurements. The model parameters are obtained using training datasets from five specimens. The effectiveness of the proposed methodology is demonstrated using several lap joint specimens from different manufactures and under different loading conditions.

  10. A multi-feature integration method for fatigue crack detection and crack length estimation in riveted lap joints using Lamb waves

    International Nuclear Information System (INIS)

    He, Jingjing; Guan, Xuefei; Peng, Tishun; Liu, Yongming; Saxena, Abhinav; Celaya, Jose; Goebel, Kai

    2013-01-01

    This paper presents an experimental study of damage detection and quantification in riveted lap joints. Embedded lead zirconate titanate piezoelectric (PZT) ceramic wafer-type sensors are employed to perform in situ non-destructive evaluation (NDE) during fatigue cyclical loading. PZT wafers are used to monitor the wave reflection from the boundaries of the fatigue crack at the edge of bolt joints. The group velocity of the guided wave is calculated to select a proper time window in which the received signal contains the damage information. It is found that the fatigue crack lengths are correlated with three main features of the signal, i.e., correlation coefficient, amplitude change, and phase change. It was also observed that a single feature cannot be used to quantify the damage among different specimens since a considerable variability was observed in the response from different specimens. A multi-feature integration method based on a second-order multivariate regression analysis is proposed for the prediction of fatigue crack lengths using sensor measurements. The model parameters are obtained using training datasets from five specimens. The effectiveness of the proposed methodology is demonstrated using several lap joint specimens from different manufactures and under different loading conditions. (paper)

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

    International Nuclear Information System (INIS)

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

    2011-01-01

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

  12. On the Process-Related Rivet Microstructural Evolution, Material Flow and Mechanical Properties of Ti-6Al-4V/GFRP Friction-Riveted Joints

    Directory of Open Access Journals (Sweden)

    Natascha Z. Borba

    2017-02-01

    Full Text Available In the current work, process-related thermo-mechanical changes in the rivet microstructure, joint local and global mechanical properties, and their correlation with the rivet plastic deformation regime were investigated for Ti-6Al-4V (rivet and glass-fiber-reinforced polyester (GF-P friction-riveted joints of a single polymeric base plate. Joints displaying similar quasi-static mechanical performance to conventional bolted joints were selected for detailed characterization. The mechanical performance was assessed on lap shear specimens, whereby the friction-riveted joints were connected with AA2198 gussets. Two levels of energy input were used, resulting in process temperatures varying from 460 ± 130 °C to 758 ± 56 °C and fast cooling rates (178 ± 15 °C/s, 59 ± 15 °C/s. A complex final microstructure was identified in the rivet. Whereas equiaxial α-grains with β-phase precipitated in their grain boundaries were identified in the rivet heat-affected zone, refined α′ martensite, Widmanstätten structures and β-fleck domains were present in the plastically deformed rivet volume. The transition from equiaxed to acicular structures resulted in an increase of up to 24% in microhardness in comparison to the base material. A study on the rivet material flow through microtexture of the α-Ti phase and β-fleck orientation revealed a strong effect of shear stress and forging which induced simple shear deformation. By combining advanced microstructural analysis techniques with local mechanical testing and temperature measurement, the nature of the complex rivet plastic deformational regime could be determined.

  13. On the Process-Related Rivet Microstructural Evolution, Material Flow and Mechanical Properties of Ti-6Al-4V/GFRP Friction-Riveted Joints

    Science.gov (United States)

    Borba, Natascha Z.; Afonso, Conrado R. M.; Blaga, Lucian; dos Santos, Jorge F.; Canto, Leonardo B.; Amancio-Filho, Sergio T.

    2017-01-01

    In the current work, process-related thermo-mechanical changes in the rivet microstructure, joint local and global mechanical properties, and their correlation with the rivet plastic deformation regime were investigated for Ti-6Al-4V (rivet) and glass-fiber-reinforced polyester (GF-P) friction-riveted joints of a single polymeric base plate. Joints displaying similar quasi-static mechanical performance to conventional bolted joints were selected for detailed characterization. The mechanical performance was assessed on lap shear specimens, whereby the friction-riveted joints were connected with AA2198 gussets. Two levels of energy input were used, resulting in process temperatures varying from 460 ± 130 °C to 758 ± 56 °C and fast cooling rates (178 ± 15 °C/s, 59 ± 15 °C/s). A complex final microstructure was identified in the rivet. Whereas equiaxial α-grains with β-phase precipitated in their grain boundaries were identified in the rivet heat-affected zone, refined α′ martensite, Widmanstätten structures and β-fleck domains were present in the plastically deformed rivet volume. The transition from equiaxed to acicular structures resulted in an increase of up to 24% in microhardness in comparison to the base material. A study on the rivet material flow through microtexture of the α-Ti phase and β-fleck orientation revealed a strong effect of shear stress and forging which induced simple shear deformation. By combining advanced microstructural analysis techniques with local mechanical testing and temperature measurement, the nature of the complex rivet plastic deformational regime could be determined. PMID:28772545

  14. MSD in fuselage lap joints: Requirements for inspection intervals for typical fuselage lap joint panels with Multiple Site Damage

    Science.gov (United States)

    Wit, G. P.

    1992-07-01

    Inspection of failed aircraft structures and fractography on fatigue specimens showed that after a high number of flights, cracks can appear simultaneously in riveted lap joints. When these crack tips approach each other, a mutual interaction causes an unexpected fast crack growth and new coalescence of cracks. The term Multiple Site Damage (MSD) is used when the mutual interaction of two or more damages is noticeable. A model to predict the fatigue life of a riveted lap joint and the minimum necessary inspection interval for safe aircraft operation is presented. The program was developed to simulate the fatigue process and aircraft inspection. Input for this analysis are scatter data for initiation, the stress distribution between frames and the geometry of the structure. Methods that can be used to avoid accidents due to MSD are reviewed. A test program to support the analysis is described.

  15. Influence of rivet to sheet edge distance on fatigue strength of self-piercing riveted aluminium joints

    OpenAIRE

    Li, Dezhi; Han, Li; Thornton, Martin; Shergold, Mike

    2012-01-01

    Self-piercing riveting (SPR) is one of the main joining methods for lightweight aluminium automotive body structures due to its advantages. In order to further optimise the structure design and reduce the weight but without compromising strength, reduction of redundant materials in the joint flange area can be considered. For this reason, the influence of rivet to sheet edge distance on the fatigue strengths of self-piercing riveted joints was studied. Five edge distances, 5 mm, 6 mm, 8 mm, 1...

  16. Fatigue Life Prediction of Self-Piercing Rivet Joints Between Magnesium and Aluminum Alloys

    Directory of Open Access Journals (Sweden)

    Kang Hong-Tae

    2018-01-01

    Full Text Available Various light materials including aluminum alloys and magnesium alloys are being used to reduce the weight of vehicle structures. Joining of dissimilar materials is always a challenging task to construct a solid structure. Self-piercing rivet (SPR joint is one of various joining methods for dissimilar materials. Front shock tower structures were constructed with magnesium alloy (AM60 joined to aluminum alloy (Al6082 by SPR joints. To evaluate the durability performance of the SPR joints in the structures, fatigue tests of the front shock tower structures were conducted with constant amplitude loadings. Furthermore, this study investigated fatigue life prediction method of SPR joints and compared the fatigue life prediction results with that of experimental results. For fatigue life prediction of the SPR joints in the front shock tower structures, lap-shear and cross-tension specimens of SPR joint were constructed and tested to characterize the fatigue properties of the SPR joint. Then, the SPR joint was represented with area contact method (ACM in finite element (FE models. The load-life curves of the lap-shear and cross-tension specimens were converted to a structural stress-life (S-N curve of the SPR joints. The S-N curve was used to predict fatigue life of SPR joints in the front shock tower structures. The test results and the prediction results were well correlated.

  17. 49 CFR 230.30 - Lap-joint seam boilers.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 4 2010-10-01 2010-10-01 false Lap-joint seam boilers. 230.30 Section 230.30..., DEPARTMENT OF TRANSPORTATION STEAM LOCOMOTIVE INSPECTION AND MAINTENANCE STANDARDS Boilers and Appurtenances Inspection and Repair § 230.30 Lap-joint seam boilers. Every boiler having lap-joint longitudinal seams...

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

    Science.gov (United States)

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

    1992-07-01

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

  19. Fatigue properties of dissimilar metal laser welded lap joints

    Science.gov (United States)

    Dinsley, Christopher Paul

    This work involves laser welding austenitic and duplex stainless steel to zinc-coated mild steel, more specifically 1.2mm V1437, which is a Volvo Truck Coiporation rephosphorised mild steel. The work investigates both tensile and lap shear properties of similar and dissimilar metal laser welded butt and lap joints, with the majority of the investigation concentrating on the fatigue properties of dissimilar metal laser welded lap joints. The problems encountered when laser welding zinc-coated steel are addressed and overcome with regard to dissimilar metal lap joints with stainless steel. The result being the production of a set of guidelines for laser welding stainless steel to zinc-coated mild steel. The stages of laser welded lap joint fatigue life are defined and the factors affecting dissimilar metal laser welded lap joint fatigue properties are analysed and determined; the findings suggesting that dissimilar metal lap joint fatigue properties are primarily controlled by the local stress at the internal lap face and the early crack growth rate of the material at the internal lap face. The lap joint rotation, in turn, is controlled by sheet thickness, weld width and interfacial gap. Laser welded lap joint fatigue properties are found to be independent of base material properties, allowing dissimilar metal lap joints to be produced without fatigue failure occurring preferentially in the weaker parent material, irrespective of large base material property differences. The effects of Marangoni flow on the compositions of the laser weld beads are experimentally characterised. The results providing definite proof of the stirring mechanism within the weld pool through the use of speeds maps for chromium and nickel. Keywords: Laser welding, dissimilar metal, Zinc-coated mild steel, Austenitic stainless steel, Duplex stainless steel, Fatigue, Lap joint rotation, Automotive.

  20. PRELIMINARY STUDIES OF RIVETED JOINTS AT FEED FORCE

    Directory of Open Access Journals (Sweden)

    Radosław Bielawski

    2015-08-01

    Full Text Available The aim of the study was to determine the feasibility of riveted joints in composites materials. Static tensile test method was used. In the test one type of glass fabric was used (Interglas 92140 from which two types of composite samples were prepared. In each sample the same type of fiber with the same fiber orientation – 3 layers - was used. The samples had dimensions of 100×100 mm and thickness of approximately 1 mm. The composite probes were located in a metal frame with a screw connection which was made of screws with nominal thread pitch M5. Screws were tightened with constant torque. It was to provide an axial force to the sample during the tensile test. The frame was placed between cross-bars of tensile machine INSTRON 8516. The samples were stretched at a speed of 0.05 mm/s at a distance up to 16 mm. During the tensile test displacement of the samples and pull force were registered. Depending on the fibre orientations and the value of feed force, damage models were described. On the basis of the results the possibility of usage of aluminium rivet nuts connections in composite materials was determined.

  1. Characterization of lap joints laser beam welding of thin AA 2024 sheets with Yb:YAG disk-laser

    Science.gov (United States)

    Caiazzo, Fabrizia; Alfieri, Vittorio; Cardaropoli, Francesco; Sergi, Vincenzo

    2012-06-01

    Lap joints obtained by overlapping two plates are widely diffused in aerospace industry. Nevertheless, because of natural aging, adhesively bonded and riveted aircraft lap joints may be affected by cracks from rivets, voids or corrosion. Friction stir welding has been proposed as a valid alternative, although large heat affected zones are produced both in the top and the bottom plate due to the pin diameter. Interest has therefore been shown in studying laser lap welding as the laser beam has been proved to be competitive since it allows to concentrate the thermal input and increases productivity and quality. Some challenges arise as a consequence of aluminum low absorptance and high thermal conductivity; furthermore, issues are due to metallurgical challenges such as both micro and macro porosity formation and softening in the fused zone. Welding of AA 2024 thin sheets in a lap joint configuration is discussed in this paper: tests are carried out using a recently developed Trumpf TruDisk 2002 Yb:YAG disk-laser with high beam quality which allows to produce beads with low plates distortion and better penetration. The influence of the processing parameters is discussed considering the fused zone extent and the bead shape. The porosity content as well as the morphological features of the beads have been examined.

  2. Identification of Nonlinear Dynamic Behavior and Failure for Riveted Joint Assemblies

    Directory of Open Access Journals (Sweden)

    B. Langrand

    2000-01-01

    Full Text Available Many different types of rivets need to be modeled to analyze the crashworthiness of aircraft structures. A numerical procedure based on FE modeling and characterization of material failure constitutive models is proposed herein with the aim of limiting the costs of experimental procedures otherwise necessary to obtain these data. Quasi-static and dynamic experiments were carried out on elementary tension (punched and shear (riveted specimens. No strain rate sensitivity was detected in the failure behavior of the riveted joint assemblies. Experimental data were used to identify the Gurson damage parameters of each material (2024-T351 and 7050 aluminum alloys for the sheet metal plate and the rivet respectively by an inverse method. Characterization gave rise to satisfactory correlation between FE models and experiments. Optimized parameters were validated for each material by means of a uniaxial tension test for the sheet metal plate and an ARCAN type specimen in pure tension for the rivet.

  3. Influence of local surface texture by tool impression on the self piercing\\ud riveting process and the static lap shear strength

    OpenAIRE

    Li, Dezhi

    2017-01-01

    To increase fuel efficiency and reduce emission, aluminium alloys have been increasingly used in automotive body-in-white structures for lightweighting. Due to its advantages over some of the more traditional joining technologies, self-piercing riveting (SPR) has been widely used for these lightweight structures. Research has showed that friction is a very important factor that influences both the riveting process and joint strength for SPR, but these influences have not been fully understood...

  4. Review on failure prediction techniques of composite single lap joint

    International Nuclear Information System (INIS)

    Ab Ghani, A.F.; Rivai, Ahmad

    2016-01-01

    Adhesive bonding is the most appropriate joining method in construction of composite structures. The use of reliable design and prediction technique will produce better performance of bonded joints. Several papers from recent papers and journals have been reviewed and synthesized to understand the current state of the art in this area. It is done by studying the most relevant analytical solutions for composite adherends with start of reviewing the most fundamental ones involving beam/plate theory. It is then extended to review single lap joint non linearity and failure prediction and finally on the failure prediction on composite single lap joint. The review also encompasses the finite element modelling part as tool to predict the elastic response of composite single lap joint and failure prediction numerically.

  5. Review on failure prediction techniques of composite single lap joint

    Energy Technology Data Exchange (ETDEWEB)

    Ab Ghani, A.F., E-mail: ahmadfuad@utem.edu.my; Rivai, Ahmad, E-mail: ahmadrivai@utem.edu.my [Faculty of Mechanical Engineering, Locked Bag 1200, Hang Tuah Jaya, 75450 Ayer Keroh, Melaka (Malaysia)

    2016-03-29

    Adhesive bonding is the most appropriate joining method in construction of composite structures. The use of reliable design and prediction technique will produce better performance of bonded joints. Several papers from recent papers and journals have been reviewed and synthesized to understand the current state of the art in this area. It is done by studying the most relevant analytical solutions for composite adherends with start of reviewing the most fundamental ones involving beam/plate theory. It is then extended to review single lap joint non linearity and failure prediction and finally on the failure prediction on composite single lap joint. The review also encompasses the finite element modelling part as tool to predict the elastic response of composite single lap joint and failure prediction numerically.

  6. SPR Characteristics Curve and Distribution of Residual Stress in Self-Piercing Riveted Joints of Steel Sheets

    OpenAIRE

    Haque, Rezwanul; Wong, Yat C.; Paradowska, Anna; Blacket, Stuart; Durandet, Yvonne

    2017-01-01

    Neutron diffraction was used to describe the residual stress distributions in self-piercing riveted (SPR) joints. The sheet material displayed a compressive residual stress near the joint, and the stress gradually became tensile in the sheet material far away from the joint. The stress in the rivet leg was lower in the thick joint of the softer steel sheet than in the thin joint of the harder steel sheet. This lower magnitude was attributed to the lower force gradient during the rivet flaring...

  7. SPR Characteristics Curve and Distribution of Residual Stress in Self-Piercing Riveted Joints of Steel Sheets

    Directory of Open Access Journals (Sweden)

    Rezwanul Haque

    2017-01-01

    Full Text Available Neutron diffraction was used to describe the residual stress distributions in self-piercing riveted (SPR joints. The sheet material displayed a compressive residual stress near the joint, and the stress gradually became tensile in the sheet material far away from the joint. The stress in the rivet leg was lower in the thick joint of the softer steel sheet than in the thin joint of the harder steel sheet. This lower magnitude was attributed to the lower force gradient during the rivet flaring stage of the SPR process curve. This study shows how the residual stress results may be related to the physical occurrences that happened during joining, using the characteristics curve. The study also shows that neutron diffraction technique enabled a crack in the rivet tip to be detected which was not apparent from a cross-section.

  8. Ultrasonic guided wave inspection of Inconel 625 brazed lap joints

    Science.gov (United States)

    Comot, Pierre; Bocher, Philippe; Belanger, Pierre

    2016-04-01

    The aerospace industry has been investigating the use of brazing for structural joints, as a mean of reducing cost and weight. There therefore is a need for a rapid, robust, and cost-effective non-destructive testing method for evaluating the structural integrity of the joints. The mechanical strength of brazed joints depends mainly on the amount of brittle phases in their microstructure. Ultrasonic guided waves offer the possibility of detecting brittle phases in joints using spatio-temporal measurements. Moreover, they offer the opportunity to inspect complex shape joints. This study focused on the development of a technique based on ultrasonic guided waves for the inspection of Inconel 625 lap joints brazed with BNi-2 filler metal. A finite element model of a lap joint was used to optimize the inspection parameters and assess the feasibility of detecting the amount of brittle phases in the joint. A finite element parametric study simulating the input signal shape, the center frequency, and the excitation direction was performed. The simulations showed that the ultrasonic guided wave energy transmitted through, and reflected from, the joints was proportional to the amount of brittle phases in the joint.

  9. Rebitagem por fricção ("FricRiveting". Desenvolvimento de uma nova técnica de união para juntas híbridas do tipo polímero-metal. Parte II: propriedades térmicas e mecânicas Friction riveting (FricRiveting. Development of a new joining technique for polymer-metal hybrid joints. Parte II: thermal and mechanical properties

    Directory of Open Access Journals (Sweden)

    Sergio T. Amancio-Filho

    2011-12-01

    Full Text Available Este artigo tem como objetivo complementar a primeira parte do estudo já publicado (Parte I, ilustrando a viabilidade da técnica FricRiveting, através da análise da temperatura processual (via termometria e termografia e desempenho mecânico (via ensaios de tração, cisalhamento e microdureza de juntas produzidas a partir de polieterimida (PEI com rebites de alumínio 2024-T351. Os resultados deste estudo mostram que a máxima temperatura de processo é próxima da temperatura de fusão do rebite de alumínio e temperatura de transformações térmicas do PEI (300ºC a 500ºC; altas temperaturas de processamento e altas taxas de deformação, implicam em excelente performance de ancoramento do rebite; e consequentemente, ótimas propriedades mecânica das juntas. Essas evidências, reforçam o grande potencial de aplicação do FricRiveting como nova técnica de união e fabricação de juntas de termoplásticos avançados e ligas leves.This present manuscript complements the work presented in the firs part of the study (Part I tackling the feasibility of the Friction Riveting (FricRiveting. This paper reports on the thermal history (the process temperature evaluated by thermometry and infrared thermography and mechanical performance (tensile strength, lap shear strength and microhardness of polyetherimide (PEI / aluminium 2024-T351 joints. The results showed average process temperatures within 300ºC to 500ºC. These are values close to the melting temperature of the aluminium rivet and the thermal degradation range of PEI. The high temperatures and shear rate induce the formation of the deformed tip of the rivet (anchoring zone responsible for the high anchoring efficiency of the rivet, and consequently, excellent mechanical properties of joints. The FricRiveting was demonstrated to be well adequate to hybrid engineering thermoplastic and lightweight alloy joints.

  10. Experimental Investigation and Finite Element Analysis on Fatigue Behavior of Aluminum Alloy 7050 Single-Lap Joints

    Science.gov (United States)

    Zhou, Bing; Cui, Hao; Liu, Haibo; Li, Yang; Liu, Gaofeng; Li, Shujun; Zhang, Shangzhou

    2018-03-01

    The fatigue behavior of single-lap four-riveted aluminum alloy 7050 joints was investigated by using high-frequency fatigue test and scanning electron microscope (SEM). Stress distributions obtained by finite element (FE) analysis help explain the fatigue performance. The fatigue test results showed that the fatigue lives of the joints depend on cold expansion and applied cyclic loads. FE analysis and fractography indicated that the improved fatigue lives can be attributed to the reduction in maximum stress and evolution of fatigue damage at the critical location. The beneficial effects of strengthening techniques result in tearing ridges or lamellar structure on fracture surface, decrease in fatigue striations spacing, delay of fatigue crack initiation, crack deflection in fatigue crack propagation and plasticity-induced crack closure.

  11. Fatigue behavior of thick composite single lap joints

    Energy Technology Data Exchange (ETDEWEB)

    Tang, J.H.; Sridhar, I.; Srikanth, N. [Nanyang Technological Univ., Singapore (Singapore)

    2012-07-01

    In consideration of bondline thickness variability, in bonded joints where thick adherend is adopted, relative thick adhesive layer (2-5 mm) is preferable. This paper aims to give some insight in fatigue strength of adhesively bonded structures involving thick adherend coupled with thick adhesive layer. Single lap joints with nominal adherend thickness of 8 mm and two different nominal thicknesses (2.5 mm and 5.5 mm) were made and tested under fatigue loading. The failure mode exhibits always a tendency for interfacial initiation, followed by interlaminar separation. Fatigue strength for higher adhesive thickness is found to be lower. (Author)

  12. Lap-joint testing of precoated steel materials

    Directory of Open Access Journals (Sweden)

    Chico, B.

    2003-12-01

    Full Text Available In industry, particularly in the building construction, lap-joint technology for precoated steel sheet materials has undergone rapid development. However, standars for lap-joint testing are lacking. This work analyses the behaviour of four precoated steel materials commonly used in the building industry: 55 % Al-Zn and hot dip galvanized, painted and unpainted. Two-year atmospheric exposure tests have been carried out in Madrid and Avilés (Spain, complemented by accelerated weathering tests in climatic cabinets. The latter have consisted of two salt fog/humidity/drying cycles: VDA cycle 621-415 and the "CENIM cycle", which has been designed to adequately simulate the behaviour of materials in this type of joints.

    En la industria en general y, particularmente, en la industria de la construcción, las tecnologías sobre uniones solapadas han experimentado un rápido desarrollo. Sin embargo, no son abundantes los ensayos para este tipo de uniones. Este trabajo analiza el comportamiento de cuatro materiales de acero pre-recubierto comúnmente usados en la industria de la construcción: 55 % Al-Zn y galvanizado por inmersión en caliente, con recubrimiento orgánico y sin él. Se han realizado ensayos de exposición natural durante dos años en las atmósferas de Madrid y Avilés (España, complementados con ensayos de envejecimiento acelerado en cámaras climáticas. En estos últimos se han ensayado dos ciclos de proyección niebla salina/humedad/secado: ciclo VDA 621-415 y un ciclo desarrollado en el CENIM diseñado.

  13. Global-Local Finite Element Analysis of Bonded Single-Lap Joints

    Science.gov (United States)

    Kilic, Bahattin; Madenci, Erdogan; Ambur, Damodar R.

    2004-01-01

    Adhesively bonded lap joints involve dissimilar material junctions and sharp changes in geometry, possibly leading to premature failure. Although the finite element method is well suited to model the bonded lap joints, traditional finite elements are incapable of correctly resolving the stress state at junctions of dissimilar materials because of the unbounded nature of the stresses. In order to facilitate the use of bonded lap joints in future structures, this study presents a finite element technique utilizing a global (special) element coupled with traditional elements. The global element includes the singular behavior at the junction of dissimilar materials with or without traction-free surfaces.

  14. Modelling and Experimental Testing of Hybrid Joints Made of: Aluminium Adherends, Adhesive Layers and Rivets for Aerospace Applications

    Directory of Open Access Journals (Sweden)

    Sadowski T.

    2017-09-01

    Full Text Available The contemporary demands in different branches of engineering require application of new multi-component materials and structural systems. Appropriately chosen joining technology can offer significant enhancement of structural system performance in terms of effectiveness, reliability, safety and other design criteria. The modern applications of complex joints are of great technological interest as they permit to combine and to enhance the individual effects of each kind of joint. This is of great importance for modern applications in different branches of engineering: aerospace, mechanical and civil. Therefore in this paper we will focus on the analysis of mechanical response of adhesive joint of aluminium strips reinforced by rivets. The aim of the paper is to investigate experimentally the mechanical behaviour of adhesive joint of aluminium strips reinforced by rivets for industrial applications in aerospace. The considered joint was subjected to uniaxial loading. The tests in this paper were performed for: • classical adhesive joint in order to investigate material parameters for numerical modelling of the hybrid joint • hybrid joining of the structural elements in order to investigate the reinforcement effect. The experiments with application of digital image ARAMIS system allowed for on-line monitoring of the deformation process of the considered joining elements. The particular distributions of displacement fields at the joint surface were estimated for any stage of loading process. Numerical modelling was performed for experimentally investigated specimens. The materials parameters, necessary for calculation, were estimated from experiments. FEA modelling was done with the help of ABAQUS code.

  15. Impact damage response of natural stitched single lap-joint in composite structures

    International Nuclear Information System (INIS)

    Ghasemnejad, H.; Argentiero, Y.; Tez, T.A.; Barrington, P.E.

    2013-01-01

    Highlights: • To study the impact resistance of single lap-joints in composite structures. • To improve the impact resistance of stitched single lap joints using natural Flax yarn. • To investigate the effect of stitching on the damage process of composite materials. • To develop FE techniques to model the impact process of composite structures using LSDYNA. - Abstract: In this paper the damage behaviour of natural stitched composite single lap-joints are investigated under low velocity impact loading conditions. For this study, the laminated hybrid composite beams were pinned using Flax yarns before curing process. The Charpy impact test was chosen to study the energy absorbing capability of single lap composite joints. Composite beams were fabricated from combination of glass/epoxy and carbon/epoxy composites. It was shown that composite beams which are stitched through the thickness are able to absorb more energy in comparison with adhesive bonded composite joints in the hybrid composite beams. The Charpy impact test of stitched composite single lap joint was also simulated by finite element analysis using software LS-DYNA and the results verified with relevant experimental data

  16. Analysis of Balanced Double Lap Joints with a Bi-Linear Softening Adhesive

    DEFF Research Database (Denmark)

    Hansen, Christian Skodborg; Stang, Henrik; Schmidt, Jacob Wittrup

    2010-01-01

    of cracked concrete disks strengthened with adhesive bonded fiber reinforced polymers (FRP), or in any other structure comparable to a double lap joint with a softening interface. The present constitutive model can be changed to fit any model with the same shape of constitutive relationship, see Figure 1.......The response of a bonded symmetric balanced double lap joint under tensile loading with a bilinear softening adhesive is described with a closed form solution. Since bonded joints in concrete structures undergo softening, a versatile model to describe the response for a wide range of constitutive...

  17. Analysis of an adhesively bonded single lap joint subjected to eccentric loading

    DEFF Research Database (Denmark)

    Anyfantis, Konstantinos; Tsouvalis, N. G.

    2013-01-01

    is benchmarking of computational tools. The test is based on a Single Lap Joint subjected to Eccentric Loading (SLJ-EL). The basic concept that lies behind this configuration is that the applied in-plane tensile load leads the adhesive layer to develop normal stresses, in-plane and out-of-plane shear stresses...

  18. Behavior of single lap composite bolted joint under traction loading: Experimental investigation

    Science.gov (United States)

    Awadhani, L. V.; Bewoor, Anand

    2018-04-01

    Composite bolted joints are preferred connection in the composite structures to facilitate the dismantling for the replacements/ maintenance work. The joint behavior under tractive forces has been studied in order to understand the safety of the structure designed. The main objective of this paper is to investigate the behavior of single-lap joints in carbon fiber reinforced epoxy composites under traction loading conditions. The experiments were designed to identify the effect of bolt diameter, stacking sequence and loading rate on the properties of the joint. The experimental results show that the parameters influence the joint performance significantly.

  19. Fatigue Damage Monitoring of a Composite Step Lap Joint Using Distributed Optical Fibre Sensors

    Science.gov (United States)

    Wong, Leslie; Chowdhury, Nabil; Wang, John; Chiu, Wing Kong; Kodikara, Jayantha

    2016-01-01

    Over the past few decades, there has been a considerable interest in the use of distributed optical fibre sensors (DOFS) for structural health monitoring of composite structures. In aerospace-related work, health monitoring of the adhesive joints of composites has become more significant, as they can suffer from cracking and delamination, which can have a significant impact on the integrity of the joint. In this paper, a swept-wavelength interferometry (SWI) based DOFS technique is used to monitor the fatigue in a flush step lap joint composite structure. The presented results will show the potential application of distributed optical fibre sensor for damage detection, as well as monitoring the fatigue crack growth along the bondline of a step lap joint composite structure. The results confirmed that a distributed optical fibre sensor is able to enhance the detection of localised damage in a structure. PMID:28773496

  20. Experimental Analysis of Stiffness of the Riveted Steel Railway Bridge Deck Members’ Joints

    Directory of Open Access Journals (Sweden)

    Gocál Jozef

    2014-12-01

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

  1. Investigation of corrosion behavior of Mg-steel laser-TIG hybrid lap joints

    Energy Technology Data Exchange (ETDEWEB)

    Liu Liming, E-mail: liulm@dlut.edu.cn [Key Laboratory of Liaoning Advanced Welding and Joining Technology, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Xu Rongzheng [Key Laboratory of Liaoning Advanced Welding and Joining Technology, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China)

    2012-01-15

    Highlights: Black-Right-Pointing-Pointer Galvanic corrosion increases the corrosion rate of the Mg-steel joint. Black-Right-Pointing-Pointer Fe splashes lower the corrosion resistance of the joint greatly. Black-Right-Pointing-Pointer The effect of grain refinement on the corrosion behavior of the joint is slight. Black-Right-Pointing-Pointer Ni or Cu interlayer could not improve the corrosion resistance of fusion zone. Black-Right-Pointing-Pointer The arc-sprayed coating could enhance the reliability of weld joint. - Abstract: The paper investigates the corrosion behavior of the lap joint of AZ31 magnesium alloy to Q235 steel with salt solution immersion testing and electrochemical testing. It is demonstrated that grain refinement resulting from the welding process has little effect on the corrosion behavior of the lap joint. However, the cathodic phases formed in the welding process and the galvanic corrosion between magnesium alloy and steel decrease the corrosion resistance of the joint greatly. Besides, neither Cu nor Ni, as filler material, could improve the corrosion resistance of the joint, but the arc-sprayed Al coating acting as a protective layer could.

  2. Investigation of corrosion behavior of Mg-steel laser-TIG hybrid lap joints

    International Nuclear Information System (INIS)

    Liu Liming; Xu Rongzheng

    2012-01-01

    Highlights: ► Galvanic corrosion increases the corrosion rate of the Mg-steel joint. ► Fe splashes lower the corrosion resistance of the joint greatly. ► The effect of grain refinement on the corrosion behavior of the joint is slight. ► Ni or Cu interlayer could not improve the corrosion resistance of fusion zone. ► The arc-sprayed coating could enhance the reliability of weld joint. - Abstract: The paper investigates the corrosion behavior of the lap joint of AZ31 magnesium alloy to Q235 steel with salt solution immersion testing and electrochemical testing. It is demonstrated that grain refinement resulting from the welding process has little effect on the corrosion behavior of the lap joint. However, the cathodic phases formed in the welding process and the galvanic corrosion between magnesium alloy and steel decrease the corrosion resistance of the joint greatly. Besides, neither Cu nor Ni, as filler material, could improve the corrosion resistance of the joint, but the arc-sprayed Al coating acting as a protective layer could.

  3. Reliability Analysis for Adhesive Bonded Composite Stepped Lap Joints Loaded in Fatigue

    DEFF Research Database (Denmark)

    Kimiaeifar, Amin; Sørensen, John Dalsgaard; Lund, Erik

    2012-01-01

    -1, where partial safety factors are introduced together with characteristic values. Asymptotic sampling is used to estimate the reliability with support points generated by randomized Sobol sequences. The predicted reliability level is compared with the implicitly required target reliability level defined......This paper describes a probabilistic approach to calculate the reliability of adhesive bonded composite stepped lap joints loaded in fatigue using three- dimensional finite element analysis (FEA). A method for progressive damage modelling is used to assess fatigue damage accumulation and residual...... by the wind turbine standard IEC 61400-1. Finally, an approach for the assessment of the reliability of adhesive bonded composite stepped lap joints loaded in fatigue is presented. The introduced methodology can be applied in the same way to calculate the reliability level of wind turbine blade components...

  4. Experimental Study on Steel to FRP Bonded Lap Joints in Marine Applications

    Directory of Open Access Journals (Sweden)

    Çiçek Özes

    2015-01-01

    Full Text Available Steel structures coated with fiber-reinforced polymer (FRP composites have gained wide acceptance in marine industry due to their high strength-to-weight ratio, good protection from environmental degradation, and impact loads. In this study, adhesive bonding performance of single-lap bonded joints composed of steel coated with FRP has been investigated experimentally for three different surface roughness and two epoxy types. Single-lap bonded joints have been tested under tensile loading. The adhesive bonding performance has been evaluated by calculating the strain energy values. The results reveal that the surface roughness of steel has a significant effect on the bonding performance of steel to FRP combinations and the performance of the resin can be improved by using the primer in an economical way.

  5. Structural assessment of a lapped scarf joint applied to historical timber constructions in central Europe

    Czech Academy of Sciences Publication Activity Database

    Kunecký, Jiří; Hasníková, Hana; Kloiber, Michal; Milch, J.; Sebera, V.; Tippner, J.

    2018-01-01

    Roč. 12, č. 4 (2018), s. 666-682 ISSN 1558-3058 R&D Projects: GA MK(CZ) DG16P02M026 Keywords : carpentry * design limit state * lap joint * numerical modeling * stiffness Subject RIV: AL - Art, Architecture, Cultural Heritage OBOR OECD: Construction engineering, Municipal and structural engineering Impact factor: 1.053, year: 2016 https://www.tandfonline.com/doi/full/10.1080/15583058.2018.1442524

  6. Single-Lap-Joint Screening of Hysol EA 9309NA Epoxy Adhesive

    Science.gov (United States)

    2017-05-01

    Acknowledgments This research was supported in part by the US Army Education Outreach Programs (Science and Engineering Apprentice Program and College...useful for estimating downstream logistical phase- out risk based on current and pending environmental regulations . Second-tier testing consists of...was used to ensure that the breaking load of single-lap-joint samples fell between 15% and 85% of the cell’s full-scale capacity. A crosshead speed

  7. Real-time monitoring of laser welding of galvanized high strength steel in lap joint configuration

    Science.gov (United States)

    Kong, Fanrong; Ma, Junjie; Carlson, Blair; Kovacevic, Radovan

    2012-10-01

    Two different cases regarding the zinc coating at the lap joint faying surface are selected for studying the influence of zinc vapor on the keyhole dynamics of the weld pool and the final welding quality. One case has the zinc coating fully removed at the faying surface; while the other case retains the zinc coating on the faying surface. It is found that removal of the zinc coating at the faying surface produces a significantly better weld quality as exemplified by a lack of spatters whereas intense spatters are present when the zinc coating is present at the faying surface. Spectroscopy is used to detect the optical spectra emitted from a laser generated plasma plume during the laser welding of galvanized high strength DP980 steel in a lap-joint configuration. A correlation between the electron temperature and defects within the weld bead is identified by using the Boltzmann plot method. The laser weld pool keyhole dynamic behavior affected by a high-pressure zinc vapor generated at the faying surface of galvanized steel lap-joint is monitored in real-time by a high speed charge-coupled device (CCD) camera assisted with a green laser as an illumination source.

  8. Effects of composite adherend properties on stresses in double lap bonded joints

    International Nuclear Information System (INIS)

    Mokhtari, M.; Madani, K.; Belhouari, M.; Touzain, S.; Feaugas, X.; Ratwani, M.

    2013-01-01

    Highlights: ► We analysis the maximal stresses distribution in the adhesive and the adherend for double lap joint. ► We modified the mechanical properties of adherend layer to decreases the stresses in adhesive layer. ► Then, we analysis the influence of modifying the types of fibers on maximal stresses distributions. ► We analysis the thickness modifications of some layers on maximal stresses distribution. ► In last, we analysis the combination of different modifications on maximal stresses distribution. -- Abstract: The effects of composite layer stiffness, thickness and ply orientations on stresses in the adhesive layer of a double lap bonded joint are investigated using three-dimensional finite element analysis code ABAQUS. A special 3-layer modelling technique is used in the finite element analysis. The non-linear behaviour of adhesive is also considered. Six composite laminates with different ply orientations are used in the lap-joint analysis. The composite materials considered in the analysis are – carbon epoxy, boron epoxy, T300/934 graphite-epoxy, and aramid epoxy. The analysis results indicate that the maximum stress in the adhesive can be significantly reduced by changing the stiffness and fibre orientations in the composite layer. Also, the use of hybrid composite (changing the nature of the fibres in two layers which are near the adhesive layer) results in reducing adhesive shear stresses.

  9. Creep analysis of adhesively bonded single lap joint using finite element method

    International Nuclear Information System (INIS)

    Zehsaz, Mohammad; Vakilitahami, Tahami Farid; Saeimisadigh, Mohammad Ali

    2014-01-01

    Adhesive joints are being used widely in engineering industries due to the increasing demand for designing lightweight structures. Because of the physical properties of the most adhesives, they creep even at room temperature. Therefore, the creep behavior of a single lap adhesive joint is studied in this paper. For this purpose, using the experimental data, creep constitutive equations for the adhesive has been obtained. Then, these equations have been employed to investigate the creep behavior of the joint. The results show that due to the creep straining, the stresses in the joint corners, decrease. However, creep strain accumulates in these areas which this in turn may lead to separation of adhesive from adherent. In order to eliminate the effect of strain accumulation, two modifying methods have been proposed in this paper: increasing the layer thickness and using filleted joints.

  10. Effect of Thread and Rotating Speed on Material Flow Behavior and Mechanical Properties of Friction Stir Lap Welding Joints

    Science.gov (United States)

    Ji, Shude; Li, Zhengwei; Zhou, Zhenlu; Wu, Baosheng

    2017-10-01

    This study focused on the effects of thread on hook and cold lap formation, lap shear property and impact toughness of alclad 2024-T4 friction stir lap welding (FSLW) joints. Except the traditional threaded pin tool (TR-tool), three new tools with different thread locations and orientations were designed. Results showed that thread significantly affected hook, cold lap morphologies and lap shear properties. The tool with tip-threaded pin (T-tool) fabricated joint with flat hook and cold lap, which resulted in shear fracture mode. The tools with bottom-threaded pin (B-tool) eliminated the hook. The tool with reverse-threaded pin (R-tool) widened the stir zone width. When using configuration A, the joints fabricated by the three new tools showed higher failure loads than the joint fabricated by the TR-tool. The joint using the T-tool owned the optimum impact toughness. This study demonstrated the significance of thread during FSLW and provided a reference to optimize tool geometry.

  11. Detection of fastener loosening in simple lap joint based on ultrasonic wavefield imaging

    Science.gov (United States)

    Gooda Sahib, M. I.; Leong, S. J.; Chia, C. C.; Mustapha, F.

    2017-12-01

    Joints in aero-mechanical structures are critical elements that ensure the structural integrity but they are prone to damages. Inspection of such joints that have no prior baseline data is really challenging but it can be possibly done using the Ultrasonic Propagation Imager (UPI). The feasibility of applying UPI for detection of loosened fastener is investigated in this study. A simple lap joint specimen made by connecting two pieces of 2.5mm thick SAE304 stainless steel plates using five M6 screws and nuts has been used in this study. All fasteners are tightened to 10Nm but one of them is completely loosened to simulate the damage. The wavefield data is processed into ultrasonic wavefield propagation video and a series of spectral amplitude images. The spectral images showed noticeable amplitude difference at the loosened fastener, hence confirmed the feasibility of using UPI for structural joints inspection. A simple contrast maximization method is also introduced to improve the result.

  12. Monitoring of fatigue damage in composite lap-joints using guided waves and FBG sensors

    Science.gov (United States)

    Karpenko, Oleksii; Khomenko, Anton; Koricho, Ermias; Haq, Mahmoodul; Udpa, Lalita

    2016-02-01

    Adhesive bonding is being increasingly employed in many applications as it offers possibility of light-weighting and efficient multi-material joining along with reduction in time and cost of manufacturing. However, failure initiation and progression in critical components like joints, specifically in fatigue loading is not well understood, which necessitates reliable NDE and SHM techniques to ensure structural integrity. In this work, concurrent guided wave (GW) and fiber Bragg grating (FBG) sensor measurements were used to monitor fatigue damage in adhesively bonded composite lap-joints. In the present set-up, one FBG sensor was strategically embedded in the adhesive bond-line of a lap-joint, while two other FBGs were bonded on the surface of the adherends. Full spectral responses of FBG sensors were collected and compared at specific intervals of fatigue loading. In parallel, guided waves were actuated and sensed using PZT wafers mounted on the composite adherends. Experimental results demonstrated that time-of-flight (ToF) of the fundamental modes transmitted through the bond-line and spectral response of FBG sensors were sensitive to fatigue loading and damage. Combination of guided wave and FBG measurements provided the desired redundancy and synergy in the data to evaluate the degradation in bond-line properties. Measurements taken in the presence of continuously applied load replicated the in-situ/service conditions. The approach shows promise in understanding the behavior of bonded joints subjected to complex loading.

  13. Friction Stir Welding-assisted Diffusion Bond of Al/Zn/Mg Lap Joint

    Directory of Open Access Journals (Sweden)

    JIN Yu-hua

    2018-03-01

    Full Text Available Dissimilar materials welding between 2mm-thick AZ31B Mg alloy and 6061 Al alloy plates in overlap form was performed using the friction stir-induced diffusion bond with zinc foil as the interlayer. The microstructure and mechanical properties of the Al/Zn/Mg lap joints were analyzed by means of SEM, EPMA, XRD, tensile experiment and Vickers hardness test. The results show that diffusion layer consists of Al enrichment zone, Al5Mg11Zn4 layer and Mg-Zn eutectic zone at proper rotation speed; however, when rotation speed is low, the residual zinc interlayer remains in the diffusion layer; when rotation speed is high, the Al-Mg intermetallic compounds are present again. Due to the existence of intermetallic compounds in diffusion layer, its microhardness is significantly higher than that of base metal. The addition of zinc foil can improve the mechanical properties of Al/Mg lap joints. According to analysis on the fracture, joint failure occurs in the diffusion layer near to Al side.

  14. Degradation of Epoxy-Steel Single Lap Joints Immersed in Water

    DEFF Research Database (Denmark)

    Goglio, L; Rezaei, Mohsen

    2015-01-01

    Exposure to environmental factors, especially moisture, is recognized as the major cause of degradation of adhesive joints. In this work, complementing a previous study on exposure to moisture, single lap joints were subjected to immersion in water, up to five weeks, at room temperature and 50 °C....... The material of the adherends was mild steel, and the adhesive was a bi-component epoxy. The specimens were fabricated using the open-face technique. Mechanical testing at the end of the relevant period of immersion showed an initial loss of ultimate load, after one week at 50 °C or two at room temperature......; then, the strength remained practically constant over the remaining time. The loss was more accentuated after immersion at 50 °C, about 70%, than at room temperature, about 30%. Also a reduction in stiffness of the joints was measured, again dramatic (about 70%) after immersion at 50 °C, moderate...

  15. Effect of friction stir lap welding conditions on joint strength of aluminium alloy 6060

    International Nuclear Information System (INIS)

    Yazdanian, S; Chen, Z W

    2009-01-01

    Strength of lap joints made by friction stir welding (FSW) depends strongly on how material flows forming the weld nugget zone during FSW and also on how the joint is loaded during testing. Understanding of this processing-property relationship is currently inadequate. In this study, the effects of pin length, welding speed and rotation rate on weld strength using aluminium alloy 6060 were investigated. It has been found that the pin length needed to be slightly greater than the thickness of the sheet for an adequate joint to be established. However, further increase in pin length did not benefit the joint strength. The major factor affecting joint strength has been found to be the rotation speed. An increase in rotation speed resulted in lowering the joint strength. Various modes of fracture have been observed and these modes relate to the degree of hooking and softening. Explanation of how the speed values relate to heat input and material flow and then to the joint strength is given.

  16. Microstructure and mechanical properties of friction stir lap welded Mg/Al joint assisted by stationary shoulder

    Science.gov (United States)

    Ji, Shude; Li, Zhengwei

    2017-11-01

    Using magnesium alloy as upper sheet, 3 mm-thick AZ31 magnesium alloy and 6061 aluminum alloy were joined using friction stir lap welding assisted by stationary shoulder. The effects of tool rotating speed on cross-sections, microstructure and mechanical properties of Mg/Al lap joints were mainly discussed. Results showed that stationary shoulder contributed to joint formation, by which stir zones (SZ) were characterized by big onion rings after welding. Because of the big forging force exerted by stationary shoulder, the upper region of hook was well bonded. SZ showed much higher hardness because of intermetallic compounds (IMCs). The bonding conditions at the base material (BM)/SZ interface at advancing side and the hook region played important roles on joint lap shear properties. The X-ray diffraction pattern analysis revealed that the main IMCs were Al3Mg2 and Al12Mg17.

  17. Nano-modified adhesive by graphene: the single lap-joint case

    Energy Technology Data Exchange (ETDEWEB)

    Silva Neto, Almir; Cruz, Diego Thadeu Lopes da; Avila, Antonio Ferreira, E-mail: aavila@netuno.lcc.ufmg.b [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia Mecanica

    2013-11-01

    This paper addresses the performance study on, low viscosity, nano-modified adhesives by graphene. For achieving this goal, single-lap joints following ASTM D 5868-01 were manufactured and tested. X-ray diffraction, scanning electron microscopy and nanoindentation were employed for graphene based nanostructures characterization. The increase on joint strength was around 57% when compared against the control group. Furthermore, all failures for the nano-modified adhesive were cohesive failure for the carbon fibre/epoxy composites indicating that the adhesive was tested. X-ray diffractions signatures indicate formation of nano-structures with 17-19 nm diameters. Moreover, nanoindentation tests revealed a homogeneous dispersion of graphene. (author)

  18. Environmental influence on the usage of adhesive single lap joints in nuclear industry applications

    International Nuclear Information System (INIS)

    Amorim, Felipe do C.; Reis, João M.L. dos; Souza, João F.B. de; Costa, Gilberto T. de P.; Moura, Jorge C. de; Universidade Federal Fluminense; Comissao Nacional de Energia Nuclear

    2017-01-01

    Despite of some polymeric compounds vulnerability to different types of radiation, high polymer, as epoxy adhesives, had prospered in the nuclear industry because their mechanical properties to high doses of ionizing radiation is maintained. Because of this, epoxy adhesives are widely used in nuclear applications: nuclear power plants, aerospace components, radioactive sealed sources to medicine, radioactive waste immobilization. In the present work, the performance of a diglycidyl ether of bisphenol ether A (DGEBA) was analyzed. Tensile tests of adhesive single lap joints bonded with epoxy were performed. The environmental effect of ultraviolet (UV) exposure was observed in the mechanical reaction of PolyAnchor 4100 HT. In particular, maximum load decreases slightly in aggressive environment. It is possible to conclude the material is proper to use in internal and external areas, mainly due to the easy application when compared to welded joints with similar strength. The easy application reduces the workers exposure time to ionizing radiation. (author)

  19. Environmental influence on the usage of adhesive single lap joints in nuclear industry applications

    Energy Technology Data Exchange (ETDEWEB)

    Amorim, Felipe do C.; Reis, João M.L. dos; Souza, João F.B. de; Costa, Gilberto T. de P.; Moura, Jorge C. de, E-mail: felipe.amorim@cefet-rj.br, E-mail: jreis@id.uff.br, E-mail: joaofellipe@id.uff.br, E-mail: gilberto.costa@cnen.gov.br, E-mail: jcmoura@cnen.gov.br [Centro Federal de Educação Tecnológica Celso Suckow da Fonseca (CEFET-RJ), Itaguai, RJ (Brazil). Departamento de Engenharia Mecanica; Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil). Laboratorio de Mecania Teorica e Aplicada; Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil). Divisão de Controle de Rejeitos e Transporte de Materiais Radioativos

    2017-07-01

    Despite of some polymeric compounds vulnerability to different types of radiation, high polymer, as epoxy adhesives, had prospered in the nuclear industry because their mechanical properties to high doses of ionizing radiation is maintained. Because of this, epoxy adhesives are widely used in nuclear applications: nuclear power plants, aerospace components, radioactive sealed sources to medicine, radioactive waste immobilization. In the present work, the performance of a diglycidyl ether of bisphenol ether A (DGEBA) was analyzed. Tensile tests of adhesive single lap joints bonded with epoxy were performed. The environmental effect of ultraviolet (UV) exposure was observed in the mechanical reaction of PolyAnchor 4100 HT. In particular, maximum load decreases slightly in aggressive environment. It is possible to conclude the material is proper to use in internal and external areas, mainly due to the easy application when compared to welded joints with similar strength. The easy application reduces the workers exposure time to ionizing radiation. (author)

  20. Strength and Failure Mechanism of Composite-Steel Adhesive Bond Single Lap Joints

    Directory of Open Access Journals (Sweden)

    Kai Wei

    2018-01-01

    Full Text Available Carbon fiber-reinforced plastics- (CFRP- steel single lap joints with regard to tensile loading with two levels of adhesives and four levels of overlap lengths were experimentally analyzed and numerically simulated. Both joint strength and failure mechanism were found to be highly dependent on adhesive type and overlap length. Joints with 7779 structural adhesive were more ductile and produced about 2-3 kN higher failure load than MA830 structural adhesive. Failure load with the two adhesives increased about 147 N and 176 N, respectively, with increasing 1 mm of the overlap length. Cohesion failure was observed in both types of adhesive joints. As the overlap length increased, interface failure appeared solely on the edge of the overlap in 7779 adhesive joints. Finite element analysis (FEA results revealed that peel and shear stress distributions were nonuniform, which were less severe as overlap length increased. Severe stress concentration was observed on the overlap edge, and shear failure of the adhesive was the main reason for the adhesive failure.

  1. Analysis on the Fracture of Al-Cu Dissimilar Materials Friction Stir Welding Lap Joint

    Science.gov (United States)

    Sun, Hongyu; Zhou, Qi; Zhu, Jun; Peng, Yong

    2017-12-01

    Friction stir welding (FWS) is regarded as a more plausible alternative to other welding methods for Al-Cu dissimilar joining. However, the structure of an FSW joint is different from others. In this study, lap joints of 6061 aluminum alloy and commercially pure copper were produced by FSW, and the effects of rotation rate on macromorphology, microstructure and mechanical properties were investigated. In addition, a fracture J integral model was used to analyze the effect of microstructure on the mechanical properties. The results revealed that the macrodefect-free joints were obtained at a feed rate of 150 mm/min and 1100 rpm and that the failure load of the joint reached as high as 4.57 kN and only reached 2.91 kN for the 900 rpm, where tunnel defects were identified. Particle-rich zones composed of Cu particles dispersed in an Al matrix, and "Flow tracks" were observed by the EDS. The J integral results showed that the microdefects on the advancing side cause serious stress concentration compared with the microdefects located on the Al-Cu interface, resulting in the fracture of the joints.

  2. Nondestructive Evaluation of Friction Stir-Welded Aluminum Alloy to Coated Steel Sheet Lap Joint

    Science.gov (United States)

    Das, H.; Kumar, A.; Rajkumar, K. V.; Saravanan, T.; Jayakumar, T.; Pal, Tapan Kumar

    2015-11-01

    Dissimilar lap joints of aluminum sheet (AA 6061) of 2 mm thickness and zinc-coated steel sheet of 1 mm thickness were produced by friction stir welding with different combinations of rotational speed and travel speed. Ultrasonic C- and B-scanning, and radiography have been used in a complementary manner for detection of volumetric (cavity and flash) and planar (de bond) defects as the defects are in micron level. Advanced ultrasonic C-scanning did not provide any idea about the defects, whereas B-scanning cross-sectional image showed an exclusive overview of the micron-level defects. A digital x-ray radiography methodology is proposed for quality assessment of the dissimilar welds which provide three-fold increase in signal-to-noise ratio with improved defect detection sensitivity. The present study clearly shows that the weld tool rotational speed and travel speed have a decisive role on the quality of the joints obtained by the friction stir welding process. The suitability of the proposed NDE techniques to evaluate the joint integrity of dissimilar FSW joints is thus established.

  3. Microstructures and mechanical properties of magnesium alloy and stainless steel weld-joint made by friction stir lap welding

    International Nuclear Information System (INIS)

    Wei, Yanni; Li, Jinglong; Xiong, Jiangtao; Huang, Fu; Zhang, Fusheng

    2012-01-01

    Highlights: → Friction stir lap welding technology with cutting pin was successfully employed to form lap joint of magnesium and steel. → The cutting pin made the lower steel participate in deformation and the interface was no longer flat. → A saw-toothed structure formed due to a mechanical mixing of the magnesium and steel was found at the interface. → A high-strength joint was produced which fractured in the magnesium side. -- Abstract: Friction stir lap welding was conducted on soft/hard metals. A welding tool was designed with a cutting pin of rotary burr made of tungsten carbide, which makes the stirring pin possible to penetrate and cut the surface layer of the hard metal. Magnesium alloy AZ31 and stainless steel SUS302 were chosen as soft/hard base metals. The structures of the joining interface were analyzed by scanning electron microscopy (SEM). The joining strength was evaluated by tensile shear test. The results showed that flower-like interfacial morphologies were presented with steel flashes and scraps, which formed bonding mechanisms of nail effect by long steel flashes, zipper effect by saw-tooth structure and metallurgical bonding. The shear strength of the lap joint falls around the shear strength of butt joint of friction stir welded magnesium alloy.

  4. Analysis of the Stringer-to-Cross-Beam Riveted Joints Behaviour

    Directory of Open Access Journals (Sweden)

    Vičan Josef

    2014-05-01

    Full Text Available The main aim of the paper is to present results of the numerical and experimental studies related to the analysis of the real stiffness of the stringer-to-cross-beam connection in order to avoid approximation of this joint by means of complicated 2D modelling and to use simplified 1D model for global analyses of bridges with open bridge decks.

  5. Corrosion Performance of Friction Stir Linear Lap Welded AM60B Joints

    Science.gov (United States)

    Kish, J. R.; Birbilis, N.; McNally, E. M.; Glover, C. F.; Zhang, X.; McDermid, J. R.; Williams, G.

    2017-11-01

    A corrosion investigation of friction stir linear lap welded AM60B joints used to fabricate an Mg alloy-intensive automotive front end sub-assembly was performed. The stir zone exhibited a slightly refined grain size and significant break-up and re-distribution of the divorced Mg17Al12 (β-phase) relative to the base material. Exposures in NaCl (aq) environments revealed that the stir zone was more susceptible to localized corrosion than the base material. Scanning vibrating electrode technique measurements revealed differential galvanic activity across the joint. Anodic activity was confined to the stir zone surface and involved initiation and lateral propagation of localized filaments. Cathodic activity was initially confined to the base material surface, but was rapidly modified to include the cathodically-activated corrosion products in the filament wake. Site-specific surface analyses revealed that the corrosion observed across the welded joint was likely linked to variations in Al distribution across the surface film/metal interface.

  6. A feasibility study for experimentally determining dynamic force distribution in a lap joint

    Energy Technology Data Exchange (ETDEWEB)

    Mayes, Randall Lee [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2013-11-01

    Developing constitutive models of the physics in mechanical joints is currently stymied by inability to measure forces and displacements within the joint. The current state of the art estimates whole joint stiffness and energy loss per cycle from external measured force input and one or two acceleration responses. To validate constitutive models beyond this state requires a measurement of the distributed forces and displacements at the joint interface. Unfortunately, introducing measurement devices at the interface completely disrupts the desired physics. A feasibility study is presented for a non-intrusive method of solving for the interface dynamic forces from an inverse problem using full field measured responses. The responses come from the viewable surface of a beam. The noise levels associated with digital image correlation and continuous scanning laser Doppler velocimetry are evaluated from typical beam experiments. Two inverse problems are simulated. One utilizes the extended Sum of Weighted Accelerations Technique (SWAT). The second is a new approach dubbed the method of truncated orthogonal forces. These methods are much more robust if the contact patch geometry is well identified. Various approaches to identifying the contact patch are investigated, including ion marker tracking, Prussian blue and ultrasonic measurements. A typical experiment is conceived for a beam which has a lap joint at one end with a single bolt connecting it to another identical beam. In a virtual test using the beam finite element analysis, it appears that the SWAT inverse method requires evaluation of too many coefficients to adequately identify the force distribution to be viable. However, the method of truncated orthogonal forces appears viable with current digital image correlation (and probably other) imaging techniques.

  7. The Effect of Wetting Gravity Regime on Shear Strength of SAC and Sn-Pb Solder Lap Joints

    Science.gov (United States)

    Sona, Mrunali; Prabhu, K. Narayan

    2017-09-01

    The failure of solder joints due to imposed stresses in an electronic assembly is governed by shear bond strength. In the present study, the effect of wetting gravity regime on single-lap shear strength of Sn-0.3Ag-0.7Cu and Sn-2.5Ag-0.5Cu solder alloys reflowed between bare copper substrates as well as Ni-coated Cu substrates was investigated. Samples were reflowed for 10 s, T gz (time corresponding to the end of gravity regime) and 100 s individually and tested for single-lap shear strength. The single-lap shear test was also carried out on eutectic Sn-Pb/Cu- and Sn-Pb/Ni-coated Cu specimens to compare the shear strength values obtained with those of lead-free alloys. The eutectic Sn-Pb showed significantly higher ultimate shear strength on bare Cu substrates when compared to Sn-Ag-Cu alloys. However, SAC alloys reflowed on nickel-coated copper substrate exhibited higher shear strength when compared to eutectic Sn-Pb/Ni-coated Cu specimens. All the substrate/solder/substrate lap joint specimens that were reflowed for the time corresponding to the end of gravity regime exhibited maximum ultimate shear strength.

  8. Numerical analysis of weld pool for galvanized steel with lap joint in GTAW

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hunchul; Park, Kyungbae; Kim, Yougjun; Cho, Jungho [Chungbuk National University, Cheongju (Korea, Republic of); Kim, Dong-Yoon; Kang, Moon-Jin [Korea Institute of Industrial Technology, Incheon (Korea, Republic of)

    2017-06-15

    Galvanized steel is widely used and its demand is growing in automotive industry due to high quality requirement for corrosion resistance. Although there are a lot of demands on using galvanized steel as automotive parts especially for outer body, it has a grave flaw in its welding process. The difficulty is low weldability due to various defects such as porosities and blow holes in weldment, which occurred during welding. A solution to prevent these defects is using hybrid welding process, with two more welding processes. One of the hybrid solutions is using Gas tungsten arc welding (GTAW) as leading position in order to remove the zinc (Zn) coating on the surface before the followed practical fusion welding process. In this research, a numerical analysis model which can predict the eliminated Zn coated layers and the area of Fusion zone (FZ). Developed numerical analysis model was validated through comparing experiment to simulation. Basically, arc heat flux, arc pressure, electromagnetic force and Marangoni flow were employed as the boundary conditions and body force terms. Governing equations such as the continuity, momentum, Volume of fluid (VOF) and energy equations were adopted as usual. In addition to previous model, concentrated arc heat flux and contact thermal conductance models are newly suggested and showed successful result. They are adopted to realize edge concentrated arc and interfacial thermal conductance in lap joint fillet arc welding. Developed numerical analysis model successfully simulated the weld pool and temperature profile therefore the predicted Zn removed area considerably coincided with experimental result.

  9. Numerical analysis of weld pool for galvanized steel with lap joint in GTAW

    International Nuclear Information System (INIS)

    Jeong, Hunchul; Park, Kyungbae; Kim, Yougjun; Cho, Jungho; Kim, Dong-Yoon; Kang, Moon-Jin

    2017-01-01

    Galvanized steel is widely used and its demand is growing in automotive industry due to high quality requirement for corrosion resistance. Although there are a lot of demands on using galvanized steel as automotive parts especially for outer body, it has a grave flaw in its welding process. The difficulty is low weldability due to various defects such as porosities and blow holes in weldment, which occurred during welding. A solution to prevent these defects is using hybrid welding process, with two more welding processes. One of the hybrid solutions is using Gas tungsten arc welding (GTAW) as leading position in order to remove the zinc (Zn) coating on the surface before the followed practical fusion welding process. In this research, a numerical analysis model which can predict the eliminated Zn coated layers and the area of Fusion zone (FZ). Developed numerical analysis model was validated through comparing experiment to simulation. Basically, arc heat flux, arc pressure, electromagnetic force and Marangoni flow were employed as the boundary conditions and body force terms. Governing equations such as the continuity, momentum, Volume of fluid (VOF) and energy equations were adopted as usual. In addition to previous model, concentrated arc heat flux and contact thermal conductance models are newly suggested and showed successful result. They are adopted to realize edge concentrated arc and interfacial thermal conductance in lap joint fillet arc welding. Developed numerical analysis model successfully simulated the weld pool and temperature profile therefore the predicted Zn removed area considerably coincided with experimental result.

  10. Reliability-based fatigue life estimation of shear riveted connections considering dependency of rivet hole failures

    Directory of Open Access Journals (Sweden)

    Leonetti* Davide

    2018-01-01

    Full Text Available Standards and guidelines for the fatigue design of riveted connections make use of a stress range-endurance (S-N curve based on the net section stress range regardless of the number and the position of the rivets. Almost all tests on which S-N curves are based, are performed with a minimum number of rivets. However, the number of rivets in a row is expected to increase the fail-safe behaviour of the connection, whereas the number of rows is supposed to decrease the theoretical stress concentration at the critical locations, and hence these aspects are not considered in the S-N curves. This paper presents a numerical model predicting the fatigue life of riveted connections by performing a system reliability analysis on a double cover plated riveted butt joint. The connection is considered in three geometries, with different number of rivets in a row and different number of rows. The stress state in the connection is evaluated using a finite element model in which the friction coefficient and the clamping force in the rivets are considered in a deterministic manner. The probability of failure is evaluated for the main plate, and fatigue failure is assumed to be originating at the sides of the rivet holes, the critical locations, or hot-spots. The notch stress approach is applied to assess the fatigue life, considered to be a stochastic quantity. Unlike other system reliability models available in the literature, the evaluation of the probability of failure takes into account the stochastic dependence between the failures at each critical location modelled as a parallel system, which means considering the change of the state of stress in the connection when a ligament between two rivets fails. A sensitivity study is performed to evaluate the effect of the pretension in the rivet and the friction coefficient on the fatigue life.

  11. Tool geometry, rotation and travel speeds effects on the properties of dissimilar magnesium/aluminum friction stir welded lap joints

    International Nuclear Information System (INIS)

    Mohammadi, J.; Behnamian, Y.; Mostafaei, A.; Gerlich, A.P.

    2015-01-01

    Highlights: • Tool geometry, rotation and travel speeds show great effect on the microstructure stability of FSW joint. • Increasing rotation and travel speeds resulted in increasing the tensile strength and ductility of the joints. • Better intermixing between Al/Mg alloys was obtained by tapered threaded pin. • A mechanical interlocking mechanism proposed for higher ductility and superior tensile properties in FSW joints. - Abstract: Lap joint friction stir welding (FSW) between dissimilar AZ31B and Al 6061 alloys sheets was conducted using various welding parameters including tool geometry, rotation and travel speeds. Tapered threaded pin and tapered pin tools were applied to fabricate FSW joints, using different rotation and travel speeds. Metallurgical investigations including X-ray diffraction pattern (XRD), optical microscopy images (OM), scanning electron microscopy equipped with an energy-dispersive X-ray spectroscopy (SEM–EDS) and electron probe microanalysis (EPMA) were used to characterize joints microstructures made with different welding parameters. Intermetallic phases were detected in the weld zone (WZ). Various microstructures were observed in the stir zone which can be attributed to using different travel and rotation speeds. Mechanical evaluation including lap shear fracture load test and microhardness measurements indicated that by simultaneously increasing the tool rotation and travel speeds, the joint tensile strength and ductility reached a maximum value. Microhardness studies and extracted results from stress–strain curves indicated that mechanical properties were affected by FSW process. Furthermore, phase analyses by XRD indicated the presence of intermetallic compounds in the weld zone. Finally, in the Al/Mg dissimilar weld, fractography studies showed that intermetallic compounds formation in the weld zone had an influence on the failure mode

  12. Ultrasonic Welding of Thermoplastic Composite Coupons for Mechanical Characterization of Welded Joints through Single Lap Shear Testing.

    Science.gov (United States)

    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.

  13. Identifying Combination of Friction Stir Welding Parameters to Maximize Strength of Lap Joints of AA2014-T6 Aluminum Alloy

    Directory of Open Access Journals (Sweden)

    Rajendrana C.

    2017-01-01

    Full Text Available AA2014 aluminum alloy (Al-Cu alloy has been widely utilized in fabrication of lightweight structures like aircraft structures, demanding high strength to weight ratio and good corrosion resistance. The fusion welding of these alloys will lead to solidification problems such as hot cracking. Friction stir welding is a new solid state welding process, in which the material being welded does not melt and recast. Lot of research works have been carried out by many researchers to optimize process parameters and establish empirical relationships to predict tensile strength of friction stir welded butt joints of aluminum alloys. However, very few investigations have been carried out on friction stir welded lap joints of aluminum alloys. Hence, in this investigation, an attempt has been made to optimize friction stir lap welding (FSLW parameters to attain maximum tensile strength using statistical tools such as design of experiment (DoE, analysis of variance (ANOVA, response graph and contour plots. By this method, it is found that maximum tensile shear fracture load of 12.76 kN can be achieved if a joint is made using tool rotational speed of 900 rpm, welding speed of 110 mm/min, tool shoulder diameter of 12 mm and tool tilt angle of 1.5°.

  14. Self-piercing riveting properties, processes and applications

    CERN Document Server

    Chrysanthou, A

    2014-01-01

    Due to its speed, low energy requirements, and the fact that it does not require a pre-drilled hole, the technique of self-piercing riveting (SPR) has been increasingly adopted by many industries as a high-speed mechanical fastening technique for the joining of sheet material components. Self-piercing riveting comprehensively reviews the process, equipment, and corrosion behaviour of self-piercing riveting, and also describes the process of evaluation and modelling of strength of self-piercing riveted joints, quality control methods and non-destructive testing.Part one provides an exte

  15. Dissimilar joining of galvanized high-strength steel to aluminum alloy in a zero-gap lap joint configuration by two-pass laser welding

    International Nuclear Information System (INIS)

    Ma, Junjie; Harooni, Masoud; Carlson, Blair; Kovacevic, Radovan

    2014-01-01

    Highlights: • Defect-free two-pass laser partially penetrated lap joint of galvanized steel to aluminum was achieved. • The thickness of the Al-rich intermetallic compounds could be controlled by optimal parameters. • The dynamic behavior of the molten pool and keyhole were monitored by a high speed charge-coupled device camera. • The presence of zinc in the intermetallic compounds could improve the strength of the lap joints. - Abstract: A welding procedure based on using two-pass laser scans is introduced for dissimilar joining of overlapped galvanized high-strength dual-phase (DP) steel DP590 to aluminum alloy (AA) 6061 sheets. The first pass is based on a defocused laser spot that scans across the top of the two overlapped sheets and heats the zinc coating at the faying surface to be melted and partially vaporized, while the second pass is executed with a focused laser spot in order to perform the welding. Completely defect-free galvanized steel to aluminum lap joints were obtained by using this two-pass laser welding procedure. An on-line machine vision system was applied to monitor the keyhole dynamics during the laser welding process. An energy-dispersive X-ray spectroscopy (EDS) was carried out to determine the atomic percent of zinc, aluminum, and iron in the galvanized steel to aluminum lap joints. Mechanical testing and micro-hardness test were conducted to evaluate the mechanical properties of the galvanized steel to aluminum lap joints. The experimental results showed that the lap joint of galvanized steel to aluminum obtained by the two-pass laser welding approach had a higher failure value than those joints obtained when the zinc at the faying surface was mechanically removed under the same welding speed and laser power

  16. Effect of Weld Bead Shape on the Fatigue Behavior of GMAW Lap Fillet Joint in GA 590 MPa Steel Sheets

    Directory of Open Access Journals (Sweden)

    Insung Hwang

    2017-09-01

    Full Text Available In this study, the effect of weld bead shape on the fatigue strength of lap fillet joints using the gas metal arc welding (GMAW process was investigated. The base material used in the experiment was 590 MPa grade galvanealed steel sheet with 2.3 mm and 2.6 mm thickness. In order to make the four types of weld beads with different shapes by factors such as length, angle, and area, the welding process, wire feeding speed, and joint shape were changed. The stress-number of cycles to failure (S–N curve and fatigue strength were obtained from the fatigue test for four types of weld bead, and the cause of the fatigue strength difference was clarified through the analysis of the geometrical factors, such as length, angle, and area of the weld bead. In addition, the relationship between weld bead shape and fatigue strength was discussed.

  17. Experimental Strength of Single-Lap Hybrid Joints on Woven Fabric Kenaf Fiber Composites Under Quasi Static Condition

    Directory of Open Access Journals (Sweden)

    Yee Lee Sim

    2016-01-01

    Full Text Available For the past decades, usage of natural fiber reinforced composites in low bearing load applications are increasing tremendously due to drawbacks concerning the use of synthetic fibers. Kenaf fibers have a good potential to be used as composite reinforcements as they possesses excellent fiber strength compared to own self-weight. Current work concentrates on mechanical properties of woven fabric kenaf composites with single-lap hybrid joints configurations. Four width to diameter ratio, (W/d of cross-ply lay-up joints as designed in testing series were tested by using quasi static mechanical testing. Experimental results showed that the failure load increased with the increasing of W/d ratios. Thinner lay-up had better bearing strength compared to thicker lay-up as found in current study.

  18. Effect of Abrasive Waterjet Peening Surface Treatment of Steel Plates on the Strength of Single-Lap Adhesive Joints

    Directory of Open Access Journals (Sweden)

    Kamil Anasiewicz

    2017-09-01

    Full Text Available The paper presents results of comparative study of shear strength of single–lap adhesive joints, depending on the method of surface preparation of steel plates with increased corrosion resistance. The method of preparing adherend surfaces is often one of the most important factors determining the strength of adhesive joints. Appropriate geometric surface development and cleaning of the surface enhances adhesion forces between adherend material and adhesive. One of the methods of shaping engineering materials is waterjet cutting, which in the AWJP – abrasive waterjet peening variant, serves to shape flat surfaces of the material by changing the roughness and introducing stresses into the surface layer. These changes are valuable when preparing adhesive joints. In the study, surface roughness parameters obtained with AWJP treatment, were analyzed in direct relation to the strength of the adhesive joint. As a consequence of the experimental results analysis, the increase in the strength of the adhesive joints was observed in a certain range of parameters used for AWJP treatment. A decrease in shear strength of adhesive joint with the most modified topography of overlap surface was observed.

  19. Defect features, texture and mechanical properties of friction stir welded lap joints of 2A97 Al-Li alloy thin sheets

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Haiyan [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi' an 710072 (China); Shaanxi Key Laboratory of Friction Welding Technologies, Northwestern Polytechnical University, Xi' an 710072 (China); Fu, Li, E-mail: fuli@nwpu.edu.cn [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi' an 710072 (China); Shaanxi Key Laboratory of Friction Welding Technologies, Northwestern Polytechnical University, Xi' an 710072 (China); Liang, Pei; Liu, Fenjun [Shaanxi Key Laboratory of Friction Welding Technologies, Northwestern Polytechnical University, Xi' an 710072 (China)

    2017-03-15

    1.4 mm 2A97 Al-Li alloy thin sheets were welded by friction stir lap welding using the stirring tools with different pin length at different rotational speeds. The influence of pin length and rotational speed on the defect features and mechanical properties of lap joints were investigated in detail. Microstructure observation shows that the hook defect geometry and size mainly varies with the pin length instead of the rotational speed. The size of hook defects on both the advancing side (AS) and the retreating side (RS) increased with increasing the pin length, leading to the effective sheet thickness decreased accordingly. Electron backscatter diffraction analysis reveals that the weld zones, especially the nugget zone (NZ), have the much lower texture intensity than the base metal. Some new texture components are formed in the thermo-mechanical affected zone (TMAZ) and the NZ of joint. Lap shear test results show that the failure load of joints generally decreases with increasing the pin length and the rotational speed. The joints failed during the lap shear tests at three locations: the lap interface, the RS of the top sheet and the AS of the bottom sheet. The fracture locations are mainly determined by the hook defects. - Highlights: • Hook defect size mainly varies with the pin length of stirring tool. • The proportion of LAGBs and substructured grains increases from NZ to TMAZ. • Weld zones, especially the NZ, have the much lower texture intensity than the BM. • Lap shear failure load and fracture location of joints is relative to the hook defects.

  20. Defect features, texture and mechanical properties of friction stir welded lap joints of 2A97 Al-Li alloy thin sheets

    International Nuclear Information System (INIS)

    Chen, Haiyan; Fu, Li; Liang, Pei; Liu, Fenjun

    2017-01-01

    1.4 mm 2A97 Al-Li alloy thin sheets were welded by friction stir lap welding using the stirring tools with different pin length at different rotational speeds. The influence of pin length and rotational speed on the defect features and mechanical properties of lap joints were investigated in detail. Microstructure observation shows that the hook defect geometry and size mainly varies with the pin length instead of the rotational speed. The size of hook defects on both the advancing side (AS) and the retreating side (RS) increased with increasing the pin length, leading to the effective sheet thickness decreased accordingly. Electron backscatter diffraction analysis reveals that the weld zones, especially the nugget zone (NZ), have the much lower texture intensity than the base metal. Some new texture components are formed in the thermo-mechanical affected zone (TMAZ) and the NZ of joint. Lap shear test results show that the failure load of joints generally decreases with increasing the pin length and the rotational speed. The joints failed during the lap shear tests at three locations: the lap interface, the RS of the top sheet and the AS of the bottom sheet. The fracture locations are mainly determined by the hook defects. - Highlights: • Hook defect size mainly varies with the pin length of stirring tool. • The proportion of LAGBs and substructured grains increases from NZ to TMAZ. • Weld zones, especially the NZ, have the much lower texture intensity than the BM. • Lap shear failure load and fracture location of joints is relative to the hook defects.

  1. Rivet usage at CMS

    Energy Technology Data Exchange (ETDEWEB)

    Radziej, Markus; Hebbeker, Thomas; Sonnenschein, Lars [III. Phys. Inst. A, RWTH Aachen (Germany)

    2015-07-01

    In this talk an overview of Rivet and its usage at the CMS experiment is presented. Rivet stands for ''Robust Independent Validation of Experiment and Theory'' and is used for optimizing and validating Monte Carlo event generators. By using the results of published analyses, distributions of the simulation can be compared to experimental measurements (corrected for detector effects). This gives insight into the agreement on the particle-level. Starting off with an introduction to the Rivet environment, the purpose of this tool in modern particle physics is explained. Before taking a closer look at the analysis structure, the software necessary to get comparisons is outlined. Analysis implementations are discussed using code examples, showcasing the powerful framework that Rivet provides. A few selected final distributions displaying both Monte Carlo generated events and recorded data are presented, showing the potential to perform particle-level comparisons.

  2. Comparison of Corner-Butt 45 (Cb-45 and Corner-Lap (Cl joints in friction stir welding

    Directory of Open Access Journals (Sweden)

    Setiawan Widia

    2018-01-01

    Full Text Available The 10 mm thick Aluminum 6061 plates have been corner joined using varied design and those were 45° Corner Butt and Corner Lap Joints (CB-45 & CL. Friction tool was hardened EMS 45. True experimental method was used with independent parameters is feed rate which varied at 10 mm/min, 15 mm/min and 30 mm/min respectively. Other parameter such as rotating speed was kept constant. Experiment results show that, CB-45 yields better properties than CL. The tensile strength of CB-45 reaches 163.7 MPa for 10 mm/min feed rate. Whilst CL produces joint with tensile strength equal 120 MPa for equal parameters. Microstructure observation showed that CB-45 produces fine and homogenous appearance of MgO compared to CL. This phenomenon is caused by the pin of CB-45 joint which fully penetrates the nugget zone which is not found in CL design. This microstructure in turn promotes higher tensile strength of CB-45.

  3. Reconstruction of fiber Bragg grating strain profile used to monitor the stiffness degradation of the adhesive layer in carbon fiber–reinforced plastic single-lap joint

    OpenAIRE

    Song Chunsheng; Zhang Jiaxiang; Yang Mo; Shang Erwei; Zhang Jinguang

    2017-01-01

    The adhesive-bonded joint of carbon fiber–reinforced plastic is one of the core components in aircraft structure design. It is an effective guarantee for the safety and reliability of the aerospace aircraft structure to use effective methods for monitoring and early warning of internal failure. In this article, the mapping relation model between the strain profiles of the adherend of the carbon fiber–reinforced plastic single-lap adhesive joint and the stiffness degradation evolution of adhes...

  4. Dual-beam laser welding of AZ31B magnesium alloy in zero-gap lap joint configuration

    Science.gov (United States)

    Harooni, Masoud; Carlson, Blair; Kovacevic, Radovan

    2014-03-01

    Porosity within laser welds of magnesium alloys is one of the main roadblocks to achieving high quality joints. One of the causes of pore formation is the presence of pre-existing coatings on the surface of magnesium alloy such as oxide or chromate layers. In this study, single-beam and dual-beam laser heat sources are investigated in relation to mitigation of pores resulting from the presence of the as-received oxide layer on the surface of AZ31B-H24 magnesium alloy during the laser welding process. A fiber laser with a power of up to 4 kW is used to weld samples in a zero-gap lap joint configuration. The effect of dual-beam laser welding with different beam energy ratios is studied on the quality of the weld bead. The purpose of this paper is to identify the beam ratio that best mitigates pore formation in the weld bead. The laser molten pool and the keyhole condition, as well as laser-induced plasma plume are monitored in real-time by use of a high speed charge-coupled device (CCD) camera assisted with a green laser as an illumination source. Tensile and microhardness tests were used to measure the mechanical properties of the laser welded samples. Results showed that a dual-beam laser configuration can effectively mitigate pore formation in the weld bead by a preheating-welding mechanism.

  5. Influence of Interface Gap on the Stress Behaviour of Smart Single Lap Joints Under Time Harmonic Load

    Directory of Open Access Journals (Sweden)

    Ivanova Jordanka

    2017-06-01

    Full Text Available Adhesive joints are frequently used in different composite structures due to their improved mechanical performance and better understanding of the failure mechanics. The application of such structures can be seen in aerospace and high technology components. The authors developed and applied modified shear lag analysis to investigate the hygrothermalpiezoelectric response of a smart single lap joint at environmental conditions (with/without an interface gap along the overlap zone and under dynamic time harmonic mechanical and electric loads. The main key is the study of the appearance of possible delamination along the interface. As illustrative examples, the analytical closed form solution of the structure shear and the axial stresses response, as well as the interface debond length, including influence of mechanical, piezoelectric, thermal characteristics and frequencies is performed and discussed. All results are presented in figures. The comparison of the shear stress and electric fields for both cases of overlap zone (continuous or with a gap is also shown in figures and discussed.

  6. Experimental and Numerical Investigations of Fretting Fatigue Behavior for Steel Q235 Single-Lap Bolted Joints

    Directory of Open Access Journals (Sweden)

    Yazhou Xu

    2016-01-01

    Full Text Available This work aims to investigate the fretting fatigue life and failure mode of steel Q235B plates in single-lap bolted joints. Ten specimens were prepared and tested to fit the S-N curve. SEM (scanning electron microscope was then employed to observe fatigue crack surfaces and identify crack initiation, crack propagation, and transient fracture zones. Moreover, a FEM model was established to simulate the stress and displacement fields. The normal contact stress, tangential contact stress, and relative slipping displacement at the critical fretting zone were used to calculate FFD values and assess fretting fatigue crack initiation sites, which were in good agreement with SEM observations. Experimental results confirmed the fretting fatigue failure mode for these specimens. It was found that the crack initiation resulted from wear regions at the contact surfaces between plates, and fretting fatigue cracks occurred at a certain distance away from hole edges. The proposed FFD-N relationship is an alternative approach to evaluate fretting fatigue life of steel plates in bolted joints.

  7. Influence of Zn Interlayer on Interfacial Microstructure and Mechanical Properties of TIG Lap-Welded Mg/Al Joints

    Science.gov (United States)

    Gao, Qiong; Wang, Kehong

    2016-03-01

    This study explored 6061 Al alloy and AZ31B Mg alloy joined by TIG lap welding with Zn foils of varying thicknesses, with the additional Zn element being imported into the fusion zone to alloy the weld seam. The microstructures and chemical composition in the fusion zone near the Mg substrate were examined by SEM and EDS, and tensile shear strength tests were conducted to investigate the mechanical properties of the Al/Mg joints, as well as the fracture surfaces, and phase compositions. The results revealed that the introduction of an appropriate amount of Zn transition layer improves the microstructure of Mg/Al joints and effectively reduces the formation of Mg-Al intermetallic compounds (IMCs). The most common IMCs in the fusion zone near the Mg substrate were Mg-Zn and Mg-Al-Zn IMCs. The type and distribution of IMCs generated in the weld zone differed according to Zn additions; Zn interlayer thickness of 0.4 mm improved the sample's mechanical properties considerably compared to thicknesses of less than 0.4 mm; however, any further increase in Zn interlayer thickness of above 0.4 mm caused mechanical properties to deteriorate.

  8. Examination of pulsed eddy current for inspection of second layer aircraft wing lap-joint structures using outlier detection methods

    Energy Technology Data Exchange (ETDEWEB)

    Butt, D.M., E-mail: Dennis.Butt@forces.gc.ca [Royal Military College of Canada, Dept. of Chemistry and Chemical Engineering, Kingston, Ontario (Canada); Underhill, P.R.; Krause, T.W., E-mail: Thomas.Krause@rmc.ca [Royal Military College of Canada, Dept. of Physics, Kingston, Ontario (Canada)

    2016-09-15

    Ageing aircraft are susceptible to fatigue cracks at bolt hole locations in multi-layer aluminum wing lap-joints due to cyclic loading conditions experienced during typical aircraft operation, Current inspection techniques require removal of fasteners to permit inspection of the second layer from within the bolt hole. Inspection from the top layer without fastener removal is desirable in order to minimize aircraft downtime while reducing the risk of collateral damage. The ability to detect second layer cracks without fastener removal has been demonstrated using a pulsed eddy current (PEC) technique. The technique utilizes a breakdown of the measured signal response into its principal components, each of which is multiplied by a representative factor known as a score. The reduced data set of scores, which represent the measured signal, are examined for outliers using cluster analysis methods in order to detect the presence of defects. However, the cluster analysis methodology is limited by the fact that a number of representative signals, obtained from fasteners where defects are not present, are required in order to perform classification of the data. Alternatively, blind outlier detection can be achieved without having to obtain representative defect-free signals, by using a modified smallest half-volume (MSHV) approach. Results obtained using this approach suggest that self-calibrating blind detection of cyclic fatigue cracks in second layer wing structures in the presence of ferrous fasteners is possible without prior knowledge of the sample under test and without the use of costly calibration standards. (author)

  9. Examination of pulsed eddy current for inspection of second layer aircraft wing lap-joint structures using outlier detection methods

    International Nuclear Information System (INIS)

    Butt, D.M.; Underhill, P.R.; Krause, T.W.

    2016-01-01

    Ageing aircraft are susceptible to fatigue cracks at bolt hole locations in multi-layer aluminum wing lap-joints due to cyclic loading conditions experienced during typical aircraft operation, Current inspection techniques require removal of fasteners to permit inspection of the second layer from within the bolt hole. Inspection from the top layer without fastener removal is desirable in order to minimize aircraft downtime while reducing the risk of collateral damage. The ability to detect second layer cracks without fastener removal has been demonstrated using a pulsed eddy current (PEC) technique. The technique utilizes a breakdown of the measured signal response into its principal components, each of which is multiplied by a representative factor known as a score. The reduced data set of scores, which represent the measured signal, are examined for outliers using cluster analysis methods in order to detect the presence of defects. However, the cluster analysis methodology is limited by the fact that a number of representative signals, obtained from fasteners where defects are not present, are required in order to perform classification of the data. Alternatively, blind outlier detection can be achieved without having to obtain representative defect-free signals, by using a modified smallest half-volume (MSHV) approach. Results obtained using this approach suggest that self-calibrating blind detection of cyclic fatigue cracks in second layer wing structures in the presence of ferrous fasteners is possible without prior knowledge of the sample under test and without the use of costly calibration standards. (author)

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

    Science.gov (United States)

    2016-04-01

    the characteristics of these data and relationships among their corresponding entities, supporting one or more application areas.”2 Digital...application, and cure) of an adhesive with unfamiliar handling characteristics . Fig. 2 Surface treating the lap-joint coupon panel using the acetone...bonding surface. It is crucial to not touch the treated tabs (specifically, the bonding area), even with gloves, after treatment is completed. Bake

  11. Lapped scarf joint with inclined faces and wooden dowels: Experimental and numerical analysis

    Czech Academy of Sciences Publication Activity Database

    Arciszewska-Kędzior, Anna; Kunecký, Jiří; Hasníková, Hana; Sebera, V.

    2015-01-01

    Roč. 94, July (2015), s. 1-8 ISSN 0141-0296 R&D Projects: GA MK(CZ) DF12P01OVV004 Keywords : timber joint * wooden-dowels * full-scale experiments * FEM * failure criterion Subject RIV: AL - Art, Architecture, Cultural Heritage Impact factor: 1.893, year: 2015 http://www.sciencedirect.com/science/article/pii/S0141029615001807

  12. Detection of defects in laser welding of AZ31B magnesium alloy in zero-gap lap joint configuration by a real-time spectroscopic analysis

    Science.gov (United States)

    Harooni, Masoud; Carlson, Blair; Kovacevic, Radovan

    2014-05-01

    The effect of surface oxide layer existing at the lap-joint faying surface of magnesium sheets is investigated on the keyhole dynamics of the weld pool and weld bead qualities. It is observed that by removing the oxide layer from the faying surface of the lap joint, a high quality weld can be achieved in the laser welding process. However, the presence of an oxide layer deteriorates the quality of the weld by forming pores at the interface of the two overlapped sheets. The purpose of this paper is to identify the correlation between the integrity of the weld and the interaction between the laser and material. A spectroscopy sensor was applied to detect the spectra emitted from a plasma plume during the laser welding of AZ31B magnesium alloy in a zero-gap lap joint configuration. The electron temperature was calculated by applying a Boltzmann plot method based on the detected spectra, and the correlation between the pore formation and the spectral signals was studied. The laser molten pool and the keyhole condition were monitored in real-time by a high speed charge-coupled device (CCD) camera. A green laser was used as an illumination source in order to detect the influence of the oxide layer on the dynamic behavior of the molten pool. Results revealed that the detected spectrum and weld defects had a meaningful correlation for real-time monitoring of the weld quality during laser welding of magnesium alloys.

  13. Numerical and Experimental Characterization of a Composite Secondary Bonded Adhesive Lap Joint Using the Ultrasonics method

    Science.gov (United States)

    Kumar, M. R.; Ghosh, A.; Karuppannan, D.

    2018-05-01

    The construction of aircraft using advanced composites have become very popular during the past two decades, in which many innovative manufacturing processes, such as cocuring, cobonding, and secondary bonding processes, have been adopted. The secondary bonding process has become less popular than the other two ones because of nonavailability of process database and certification issues. In this article, an attempt is made to classify the quality of bonding using nondestructive ultrasonic inspection methods. Specimens were prepared and tested using the nondestructive ultrasonic Through Transmission (TT), Pulse Echo (PE), and air coupled guided wave techniques. It is concluded that the ultrasonic pulse echo technique is the best one for inspecting composite secondary bonded adhesive joints.

  14. X-ray method for studying butt gapp distribution and spliced joints in lapped paper and plastic cables

    International Nuclear Information System (INIS)

    Muller, A.C.

    1976-01-01

    Accurate taping patterns are essential in paper and plastic lapped underground cables. A newly developed radiographic system makes it possible to examine the structure of cables and splices in a nondestructive manner. This technique appears to be an effective tool for use in both the monitoring of the accuracy of lapping techniques and as an aid in locating defective portions of existing cables. A discussion of the method and some preliminary results are reported

  15. Fusion welding of Fe-added lap joints between AZ31B magnesium alloy and 6061 aluminum alloy by hybrid laser-tungsten inert gas welding technique

    International Nuclear Information System (INIS)

    Qi, Xiao-dong; Liu, Li-ming

    2012-01-01

    Highlights: → Hybrid Laser-TIG fusion welding technique was used for joining Mg to Al alloys. → Laser defocusing amount determined penetration depth inside Al alloy of joints. → The addition of Fe interlayer suppressed Mg-Al intermetallics greatly in joints. → A maximum joint strength with optimum thickness of Fe interlayer was obtained. → Excessive addition of Fe interlayer was adverse for the strength improvement. -- Abstract: AZ31B magnesium alloy and 6061-T6 aluminum alloy were lap joined together with the addition of Fe interlayer by fusion welding of hybrid laser-tungsten inert gas (TIG) technique. The influence of location of laser focal spot (LFS) on joint penetration depth and that of the depth on joint strength were investigated. The results showed that when the LFS was just on the surface of Al plate, the deepest penetration could be obtained, which contributed to the improvement of shear strength of Fe-added joints, but not to the elevation of the strength of Mg/Al direct joints. The addition of Fe interlayer suppressed massive production of Mg-Al intermetallics but produced Fe-Al intermetallics in the fusion zone of the joints, whose micro-hardness was extremely high and was also adverse for the enhancement of joint shear strength. The effect of Fe-interlayer thickness on the joint shear strength was also examined, and the maximum shear strength of Fe-added joint could achieve 100 MPa with 0.13 mm thick Fe interlayer. The fracture modes of 0.07 and 0.13 mm Fe-interlayer-added joints were both quasi-cleavage, while those of direct and 0.22 mm interlayer-added joints were completely cleavage. The theoretical shear strength of the Fe-added joints was also discussed.

  16. Reconstruction of fiber Bragg grating strain profile used to monitor the stiffness degradation of the adhesive layer in carbon fiber–reinforced plastic single-lap joint

    Directory of Open Access Journals (Sweden)

    Song Chunsheng

    2017-01-01

    Full Text Available The adhesive-bonded joint of carbon fiber–reinforced plastic is one of the core components in aircraft structure design. It is an effective guarantee for the safety and reliability of the aerospace aircraft structure to use effective methods for monitoring and early warning of internal failure. In this article, the mapping relation model between the strain profiles of the adherend of the carbon fiber–reinforced plastic single-lap adhesive joint and the stiffness degradation evolution of adhesive layer was achieved by finite element software ABAQUS. The fiber Bragg grating was embedded in the adherend between the first and second layers at the end of the adhesive layer to calculate the reflection spectrum of fiber Bragg grating sensor region with improved T-matrix method for reconstruction of the adherend strain profile of fiber Bragg grating sensing area with the help of genetic algorithm. According to the reconstruction results, the maximum error between the ideal and reconstructed strain profile under different tension loads did not exceed 7.43%, showing a good coincidence degree. The monitoring method of the stiffness degradation evolution of adhesive layer of the carbon fiber–reinforced plastic single-lap joint based on the reconstruction of the adherend strain profile of fiber Bragg grating sensing area thus was figured out.

  17. 3D finite element analysis of stress distributions and strain energy release rates for adhesive bonded flat composite lap shear joints having pre-existing delaminations

    Energy Technology Data Exchange (ETDEWEB)

    Parida, S. K.; Pradhan, A. K. [Indian Institute of Technology, Bhubaneswar (India)

    2014-02-15

    The rate of propagation of embedded delamination in the strap adherend of lap shear joint (LSJ) made of carbon/epoxy composites has been evaluated employing three-dimensional non-linear finite elements. The delamination has been presumed to pre-exist in the thin resin layer between the first and second plies of the strap adherend. The inter-laminar peel and shear stress distributions have been studied in details and are seen to be predominantly three-dimensional in nature. The components of strain energy release rate (SERR) corresponding to the opening, sliding and cross sliding modes of delamination are significantly different at the two fronts of the embedded delamination. The sequential release of multi-point constraint (MPC) finite elements in the vicinity of the delamination fronts enables to simulate the growth of the delamination at either ends. This simulation procedure can be utilized effectively for evaluation of the status of the structural integrity of the bonded joints.

  18. Abnormal accumulation of intermetallic compound at cathode in a SnAg3.0Cu0.5 lap joint during electromigration

    International Nuclear Information System (INIS)

    Li Mingyu; Chang Hong; Pang Xiaochao; Wang Ling; Fu Yonggao

    2011-01-01

    Interfacial reactions in a SnAg 3.0 Cu 0.5 /Cu lap joint for naked and encompassed specimens were investigated contrastively under electric current stressing. After applying a constant direct current at 6.5 A for 144 h, an abnormal accumulation of bulk Cu 6 Sn 5 intermetallic compound was found at the cathode for the naked specimen. But normal polarization phenomenon arose for the encompassed specimen at the same current density for 504 h. The abnormal accumulation phenomenon was explained by the mechanism that thermomigration and stress migration induced by temperature gradient dominated the migration process. A three-dimensional joint simulation model was designed to demonstrate how current crowding and temperature gradient can enhance the local atomic flux.

  19. Dynamic strain distribution measurement and crack detection of an adhesive-bonded single-lap joint under cyclic loading using embedded FBG

    International Nuclear Information System (INIS)

    Ning, Xiaoguang; Murayama, Hideaki; Kageyama, Kazuro; Wada, Daichi; Kanai, Makoto; Ohsawa, Isamu; Igawa, Hirotaka

    2014-01-01

    In this study, the dynamic strain distribution measurement of an adhesive-bonded single-lap joint was carried out in a cyclic load test using a fiber Bragg grating (FBG) sensor embedded into the adhesive/adherend interface along the overlap length direction. Unidirectional carbon fiber reinforced plastic (CFRP) substrates were bonded by epoxy resin to form the joint, and the FBG sensor was embedded into the surface of one substrate during its curing. The measurement was carried out with a sampling rate of 5 Hz by the sensing system, based on the optical frequency domain reflectometry (OFDR) throughout the test. A finite element analysis (FEA) was performed for the measurement evaluation using a three-dimensional model, which included the embedded FBG sensor. The crack detection method, based on the longitudinal strain distribution measurement, was introduced and performed to estimate the cracks that occurred at the adhesive/adherend interface in the test. (paper)

  20. Bearing Stress at Failure of Double-Lap Hybrid Joints in Woven Fabric Kenaf Fiber Composite Plates under Quasi-static Loading

    Directory of Open Access Journals (Sweden)

    Lee Sim Yee

    2017-01-01

    Full Text Available The present paper is focused on the bearing stress at failure of double-lap woven fabric kenaf fiber reinforced polymer (KFRP hybrid bonded-bolted joints in experimental frameworks. The effects of different normalized plate width (plate width/hole diameter, W/d, lay-up types and bolt loads were incorporated in current study as specified in testing series. Generally, hybrid joint coupons separated within adhesive layer prior to net-tension failure or bearing/net-tension failure. The bearing stress at failure increased as W/d ratio increment, critical W/d is given as four and three in clamped and finger tight condition respectively. Lay-up types present insignificant effect to bearing stress at failure due to low volume fiber fraction in kenaf fiber composites. Combination of thicker and clamped conditions plate demonstrated greater bearing stress than equivalent finger-tight (FT conditions due to higher load transferred from friction, as expected.

  1. Friction riveting. Development and analysis of a new joining technique for polymer-metal multi-materials structures

    Energy Technology Data Exchange (ETDEWEB)

    Amancio, S.

    2007-07-01

    A new Friction Riveting technique for polymeric-metallic joints was developed, demonstrated and characterized in this work, as an alternative, reliable, environmental compatible and economically viable spot joining process. In the simplest process variant a rotating cylindrical metallic rivet is inserted in a thermoplastic base plate. The high rotation speed and pressure increase friction and heat is generated. The local increase in temperature induces the formation of a softened/molten polymer layer around the tip of the rotating rivet. When a certain penetration depth is achieved the heat input rate becomes higher than heat outflow (owing to the low polymer thermal conductivity), temperature highly increases and the rivet tip plasticizes. At this point rotation is stopped and the forging pressure applied, so the plasticized rivet tip is deformed by the opposite reactive forces of colder polymeric volumes, assuming a paraboloidal pattern; after cooling it becomes anchored in the polymeric base plate. In this work case-study joints on commercially available polyetherimide (PEI) and aluminium 2024- T351(Al-Cu-Mg alloy) were chosen for demonstrating proposed theories, models and mechanisms, as well as an analytical heat input model. Sound friction riveted point-on-plate and single-rivet overlap joints with elevated joint efficiencies in terms of base materials strength were obtained (joint efficiencies for point-on-plate joints: 60 %.93 %; for overlaps: 70 %) through tensile and lap shear testing at room temperature. The influence of process parameters (rotational speed, total time and total pressure) on process variables and joint properties were evaluated by thermometry, infrared thermography, microscopy, Vickers microhardness, X-ray microtomography and by gel permeation chromatography. Temperature (average maximal temperatures 500 deg C) was directly proportional to rotation speed, total time and total pressure. Volumetric flaw formation was directly proportional

  2. Study of failure mechanism of double-lap joints of steel to FRP by bolt and resin

    Directory of Open Access Journals (Sweden)

    Amir Hossein Zakeri

    2017-05-01

    Full Text Available In this study, the behavior of joints in two sides of steel coat which are screwed to the composite plate, and joints of two sides of compound steel coat (bolted and bonded to the composite plate has been studied. In the standards, distance of mechanical bolts from the edges and the distance of mechanical bolts from each other have been discussed. Different distances in the range of the standards determined for the distance of screws from edges and screws from each other. In this paper, the screw joints and the combined joints with different terminal distances for screws from the edges are modeled and studied. The results showed the basic effects of the terminal distance of the screw from the connection edges on the resistance and mechanism of break of screw joints. In combined joints, the terminal distance of the screw had trivial effects in the resistance and mechanism of joint break. In addition, overlap length of the connection elements on increase of joint resistance analyzed and studied. To do so, a combined joint with configuration of two steel plates and one CFRP/GFRP composite plates which were joined by two screws and adhesive layers with different overlap were modeled. The results showed the direct relationship between increase of overlap length and increase in resistance of the joint. Finally, a design guide to be used in practice was proposed.

  3. Characterization of Coatings on Steel Self-Piercing Rivets for Use with Magnesium Alloys

    Science.gov (United States)

    McCune, Robert C.; Forsmark, Joy H.; Upadhyay, Vinod; Battocchi, Dante

    Incorporation of magnesium alloys in self-pierce rivet (SPR) joints poses several unique challenges among which are the creation of spurious galvanic cells and aggravated corrosion of adjacent magnesium when coated steel rivets are employed. This work firstly reviews efforts on development of coatings to steel fasteners for the diminution of galvanic corrosion when used with magnesium alloys. Secondly, approaches, based on several electrochemical methods, for the measurement of the galvanic-limiting effect of a number of commercially-available coatings to hardened 10B37 steel self-piercing rivets inserted into alloy couples incorporating several grades of magnesium are reported. Electrochemical impedance spectroscopy (EIS), zero-resistance ammeter (ZRA), corrosion potential and potential-mapping visualization methods (e.g. scanning vibrating electrode technique — SVET) are illustrated for the several rivet coatings considered.

  4. Experimental and numerical studies on the issues in laser welding of light-weight alloys in a zero-gap lap joint configuration

    Science.gov (United States)

    Harooni, Masoud

    current study a non-destructive evaluation method based on spectroscopy is proposed to detect the presence of pores in the lap joint of laser welded AZ31B magnesium alloy. The electron temperature that is calculated by the Boltzmann plot method is correlated to the presence of pores in the weld bead. A separate series of experiments was performed to evaluate the effect of an oxide coating layer on the dynamic behavior of the molten pool in the laser welding of an AZ31B magnesium alloy in a zero-gap lap joint configuration. A high speed CCD camera assisted with a green laser as an illumination source was selected to record the weld pool dynamics. Another technique used in this study was two-pass laser welding process to join AZ31B magnesium sheet in a zero-gap, lap-shear configuration. Two groups of samples including one pass laser welding (OPLW) and two pass laser welding (TPLW) were studied. In the two pass laser welding procedure, the first pass is performed by a defocused laser beam on the top of the two overlapped sheets in order to preheat the faying surface prior to laser welding, while the second pass is applied to melt and eventually weld the samples. Tensile and microhardness tests were used to measure the mechanical properties of the laser welded samples. A spectrometer was also used in real-time to correlate pore formation with calculated electron temperature using the Boltzmann plot method. The results of calculated electron temperature confirmed the previous results in earlier chapter. Magnesium and aluminum are two alloys which are used in different industries mainly due to their light weight. The main use of these two alloys is in automotive industry. Since different parts of the automobiles can be manufactured with each of these two alloys, it is essential to evaluate the joining feasibility of dissimilar metals such as aluminum to magnesium. A 4 kW fiber laser is used to join AZ31B magnesium alloy to AA 6014 using an overlap joint configuration. Two

  5. Caring for Rosie the Riveter's Children

    Science.gov (United States)

    MacKenzie, Bill

    2011-01-01

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

  6. Development of all-beryllium riveted structures

    International Nuclear Information System (INIS)

    Floyd, D.R.; Leslie, W.W.; Miley, D.V.; Nokes, R.W.

    1976-01-01

    Results are presented of a development program aimed at making a full-scale, all-beryllium frustrum by riveted assembly methods. Included are descriptions of the sheet-metal fabrication practices and assembly plans. Results of extensive mechanical testing of both ingot- and powder-source beryllium products that are presented include tensile, notch-tensile, bearing, and shear tests. Although the full-size structure has not been built, examples are given of several conical and cylindrical structures that were made. The largest of these is a 20-in. diameter, 15-in. long cylinder that was roll-formed from one 0.050-in. thick ingot sheet and assembled with 60 countersunk rivets. Tensile testing of riveted flat coupons is also reported as is bulge testing of riveted cylindrical shells. A cost comparison of riveted deep-drawn and powder-source cylinders is made. Results show that when strength and dimensional tolerance requirements are not severe, a riveted assembly approach is warranted. 33 figures, 8 tables

  7. Online visual inspection of self-piercing riveting to determine the quality of the mechanical interlock

    International Nuclear Information System (INIS)

    Johnson, P; Cullen, J D; Al-Shamma'a, A I; Shaw, A

    2007-01-01

    Self-piercing riveting (SPR) has become a significant joining technique for the automotive applications of aluminium sheets. Quality control in this locale has progressed at an altogether more leisurely rate than other areas of mechanical joining (e.g. spotweld) and is underdeveloped. Testing the quality mechanical interlock is often achieved by destructive testing, which results in material and time wastage. The solution is online monitoring of the self-piercing riveting process to provide non-destructive testing of the mechanical interlock. Introducing sensors into the process facilitates real time data acquisition, which can be used to determine the quality of the joint

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

    Science.gov (United States)

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

    1994-01-01

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

  9. Self-piercing riveting - a review

    OpenAIRE

    Li, Dezhi; Chrysanthou, Andreas; Patel, Imran; Williams, Geraint J.

    2017-01-01

    Self-piercing riveting (SPR) is a cold mechanical joining process used to join two or more sheets of materials by driving a rivet piercing through the top sheet or the top and middle sheets and subsequently lock into the bottom sheet under the guidance of a suitable die. SPR is currently the main joining method for aluminium and mixed-material lightweight automotive structures. SPR was originated half century ago, but it only had significant progress in the last 25 years due to the requiremen...

  10. [Sample German LAPS.

    Science.gov (United States)

    Rosenthal, Bianca

    Four learning activity packages (LAPS) for use in secondary school German programs contain instructional materials which enable students to improve their basic linguistic skills. The units include: (1) "Grusse," (2) "Ich Heisse...Namen," (3) "Tune into Your Career: Business Correspondence 'Auf Deutch'," and (4) "Understanding German Culture."…

  11. The LapSlapper

    DEFF Research Database (Denmark)

    Andresen, Mads Stenhøj; Bach, Morten; Kristensen, Kristian Ross

    2010-01-01

    The LapSlapper is an inexpensive and low-technology percussive instrument with a digital interface. In a tactile and embodied manner it allows enhanced control and promotes expressive creativity when operating with percussive elements in digital environments. By using piezo-microphones, mounted...

  12. Laser assisted self-pierce riveting of AZ31 magnesium alloy strips

    International Nuclear Information System (INIS)

    Durandet, Y.; Deam, R.; Beer, A.; Song, W.; Blacket, S.

    2010-01-01

    Laser assisted self-piercing riveting (LSPR) is a new solid state process that enables low ductility materials to be mechanically joined without cracking. A simple but effective thermal analysis of LSPR is presented that enabled both the absorption of the laser radiation and heat transfer between plies to be determined. The approach was applied to experimental data for LSPR joining of AZ31B-H24 magnesium alloy sheets. It is shown that by using this analytical approach, the temperature at the onset of joining could be estimated and related to observations of joint quality. It was found that crack-free joints were produced at strip temperatures above 200 o C at the time of rivet insertion.

  13. Influence of heat treatment on fatigue performances for self-piercing riveting similar and dissimilar titanium, aluminium and copper alloys

    OpenAIRE

    Zhang, Xianlian; He, Xiaocong; Xing, Baoying; Zhao, Lun; Lu, Yi; Gu, Fengshou; Ball, Andrew

    2016-01-01

    The fatigue performances of self-piercing riveting (SPR) joints connecting similar and dissimilar sheets of TA1 titanium alloy (TA1), Al5052 aluminium alloy (Al5052) and H62 copper alloy (H62) were studied in this paper. The specimens of similar TA1 sheets treated with stress relief annealing were prepared to investigate the influence of relief annealing on the mechanical properties of SPR joints. Fatigue tests were conducted to characterize the fatigue lives and failure modes of the joints. ...

  14. Finite Element Analysis for Fatigue Damage Reduction in Metallic Riveted Bridges Using Pre-Stressed CFRP Plates

    Directory of Open Access Journals (Sweden)

    Elyas Ghafoori

    2014-04-01

    Full Text Available Many old riveted steel bridges remain operational and require retrofit to accommodate ever increasing demands. Complicating retrofit efforts, riveted steel bridges are often considered historical structures where structural modifications that affect the original construction are to be avoided. The presence of rivets along with preservation requirements often prevent the use of traditional retrofit methods, such as bonding of fiber reinforced composites, or the addition of supplementary steel elements. In this paper, an un-bonded post-tensioning retrofit method is numerically investigated using existing railway riveted bridge geometry in Switzerland. The finite element (FE model consists of a global dynamic model for the whole bridge and a more refined sub-model for a riveted joint. The FE model results include dynamic effects from axle loads and are compared with field measurements. Pre-stressed un-bonded carbon fiber reinforced plastic (CFRP plates will be considered for the strengthening elements. Fatigue critical regions of the bridge are identified, and the effects of the un-bonded post-tensioning method with different pre-stress levels on fatigue susceptibility are explored. With an applied 40% CFRP pre-stress, fatigue damage reductions of more than 87% and 85% are achieved at the longitudinal-to-cross beam connections and cross-beam bottom flanges, respectively.

  15. Friction riveting as an alternative mechanical fastening to join engineering plastics

    Science.gov (United States)

    Gagliardi, Francesco; Conte, Romina; Bentrovato, Renato; Simeoli, Giorgio; Russo, Pietro; Ambrogio, Giuseppina

    2018-05-01

    Friction Rivecting is a quite new joining process to connect multi-material structures. In brief, a metallic rivet is dipped rotating inside matrixes, usually made of plastics, increasing its original diameter. The use of high-performance plastics is more suitable being their higher mechanical and thermal properties important to avoid material degradation and to allow strong part connections. High-speed friction welding system has been usually used to perform the process. In the work here proposed, the joints have been achieved by means of a traditional milling machine and the attention has been focused on a widely used engineering plastic, i.e. polyamide 6 (PA6) with and without glass fiber reinforcement. A specific speed multiplier has been attached into the mandrel of the used machine to increase the reachable rotational speed. Moreover, rivets made of Titanium Grade 2 and of an Aluminum Alloy, the AA-6060, are utilized. The influence that the heating and the forging length can have on the quality of the obtained junctions, considering a fixed joining depth, has been tested and investigated. The performed connections have been judged by tensile tests, which were set to quantify the maximum strength of the joints for a transverse speed of 1,0 mm/min. Barreling effect can be observed close to the tip, which loses the initial shape of a cylinder characterized by straight vertical walls. Finally, the possible degradation of the polymer, due to temperature increment, has been also evaluated close to the working zone. According to that, it has to be highlighted that the process needs a heating balance, which is necessary to get sound joints. The compromise has, on one side, to allow the rivet penetration and deformation, and on the other side, to avoid the degradation of the polymer, which would affect its properties and a proper rivet deformation.

  16. Fracture Mechanics Approach to X-Ray Diffraction Method for Spot Welded Lap Joint Structure of Rolled Steel Considered Residual Stress

    International Nuclear Information System (INIS)

    Baek, Seung Yeb; Bae, Dong Ho

    2011-01-01

    Cold and hot-rolled carbon steel sheets are commonly used in railroad cars or commercial vehicles such as the automobile. The sheets used in these applications are mainly fabricated by spot welding, which is a type of electric resistance welding. However, the fatigue strength of a spot-welded joint is lower than that of the base metal because of high stress concentration at the nugget edge of the spot-welded part. In particular, the fatigue strength of the joint is influenced by not only geometrical and mechanical factors but also the welding conditions for the spot-welded joint. Therefore, there is a need for establishing a reasonable criterion for a long-life design for spot-welded structures. In this thesis, ΔP-N f relation curves have been used to determine a long-life fatigue-design criterion for thin-sheet structures. However, as these curves vary under the influence of welding conditions, mechanical conditions, geometrical factors, etc. It is very difficult to systematically determine a fatigue-design criterion on the basis of these curves. Therefore, in order to eliminate such problems, the welding residual stresses generated during welding and the stress distributions around the weld generated by external forces were numerically and experimentally analyzed on the basis of the results, reassessed fatigue strength of gas welded joints

  17. Experimental assessment of a full-scale lap scarf timber joint accompanied by a finite element analysis and digital image correlation

    Czech Academy of Sciences Publication Activity Database

    Kunecký, Jiří; Sebera, V.; Hasníková, Hana; Arciszewska-Kędzior, Anna; Tippner, J.; Kloiber, Michal

    2015-01-01

    Roč. 76, February (2015), s. 24-33 ISSN 0950-0618 R&D Projects: GA MK(CZ) DF12P01OVV004 Keywords : historicist joint * full-scale testing * finite element analysis * dowel * digital image correlation Subject RIV: AL - Art, Architecture, Cultural Heritage Impact factor: 2.421, year: 2015 http://www.sciencedirect.com/science/article/pii/S095006181401246X

  18. Lap belt injuries in children.

    LENUS (Irish Health Repository)

    McGrath, N

    2010-07-01

    The use of adult seat belts without booster seats in young children may lead to severe abdominal, lumbar or cervical spine and head and neck injuries. We describe four characteristic cases of lap belt injuries presenting to a tertiary children\\'s hospital over the past year in addition to a review of the current literature. These four cases of spinal cord injury, resulting in significant long-term morbidity in the two survivors and death in one child, arose as a result of lap belt injury. These complex injuries are caused by rapid deceleration characteristic of high impact crashes, resulting in sudden flexion of the upper body around the fixed lap belt, and consequent compression of the abdominal viscera between the lap belt and spine. This report highlights the dangers of using lap belts only without shoulder straps. Age-appropriate child restraint in cars will prevent these injuries.

  19. Sequential lineup laps and eyewitness accuracy.

    Science.gov (United States)

    Steblay, Nancy K; Dietrich, Hannah L; Ryan, Shannon L; Raczynski, Jeanette L; James, Kali A

    2011-08-01

    Police practice of double-blind sequential lineups prompts a question about the efficacy of repeated viewings (laps) of the sequential lineup. Two laboratory experiments confirmed the presence of a sequential lap effect: an increase in witness lineup picks from first to second lap, when the culprit was a stranger. The second lap produced more errors than correct identifications. In Experiment 2, lineup diagnosticity was significantly higher for sequential lineup procedures that employed a single versus double laps. Witnesses who elected to view a second lap made significantly more errors than witnesses who chose to stop after one lap or those who were required to view two laps. Witnesses with prior exposure to the culprit did not exhibit a sequential lap effect.

  20. Development of all-beryllium riveted structures. [Frustrum; cylinders; cones

    Energy Technology Data Exchange (ETDEWEB)

    Floyd, D. R.; Leslie, W. W.; Miley, D. V.; Nokes, R. W.

    1976-04-20

    Results are presented of a development program aimed at making a full-scale, all-beryllium frustrum by riveted assembly methods. Included are descriptions of the sheet-metal fabrication practices and assembly plans. Results of extensive mechanical testing of both ingot- and powder-source beryllium products that are presented include tensile, notch-tensile, bearing, and shear tests. Although the full-size structure has not been built, examples are given of several conical and cylindrical structures that were made. The largest of these is a 20-in. diameter, 15-in. long cylinder that was roll-formed from one 0.050-in. thick ingot sheet and assembled with 60 countersunk rivets. Tensile testing of riveted flat coupons is also reported as is bulge testing of riveted cylindrical shells. A cost comparison of riveted deep-drawn and powder-source cylinders is made. Results show that when strength and dimensional tolerance requirements are not severe, a riveted assembly approach is warranted. 33 figures, 8 tables. (auth)

  1. Design of mechanical joints

    CERN Document Server

    Blake, Alexander

    2018-01-01

    A cornerstone publication that covers the basic principles and practical considerations of design methodology for joints held by rivets, bolts, weld seams, and adhesive materials, Design of Mechanical Joints gives engineers the practical results and formulas they need for the preliminary design of mechanical joints, combining the essential topics of joint mechanics...strength of materials...and fracture control to provide a complete treatment of problems pertinent to the field of mechanical connections.

  2. Additive manufacturing of tools for lapping glass

    Science.gov (United States)

    Williams, Wesley B.

    2013-09-01

    Additive manufacturing technologies have the ability to directly produce parts with complex geometries without the need for secondary processes, tooling or fixtures. This ability was used to produce concave lapping tools with a VFlash 3D printer from 3D Systems. The lapping tools were first designed in Creo Parametric with a defined constant radius and radial groove pattern. The models were converted to stereolithography files which the VFlash used in building the parts, layer by layer, from a UV curable resin. The tools were rotated at 60 rpm and used with 120 grit and 220 grit silicon carbide lapping paste to lap 0.750" diameter fused silica workpieces. The samples developed a matte appearance on the lapped surface that started as a ring at the edge of the workpiece and expanded to the center. This indicated that as material was removed, the workpiece radius was beginning to match the tool radius. The workpieces were then cleaned and lapped on a second tool (with equivalent geometry) using a 3000 grit corundum aluminum oxide lapping paste, until a near specular surface was achieved. By using lapping tools that have been additively manufactured, fused silica workpieces can be lapped to approach a specified convex geometry. This approach may enable more rapid lapping of near net shape workpieces that minimize the material removal required by subsequent polishing. This research may also enable development of new lapping tool geometry and groove patterns for improved loose abrasive finishing.

  3. Numerical simulation of self-piercing riveting process (SRP using continuum damage mechanics modelling

    Directory of Open Access Journals (Sweden)

    Nicola Bonora

    2018-04-01

    Full Text Available The extended Bonora damage model was used to investigate joinability of materials in self-piercing riveting process. This updated model formulation accounts for void nucleation and growth process and shear-controlled damage which is critical for shear fracture sensitive materials. Potential joint configurations with dissimilar materials have been investigated computationally. In particular the possible combination of DP600 steel, which is widely used in the automotive industry, with AL2024-T351, which is known to show shear fracture sensitivity, and oxygen-free pure copper, which is known to fail by void nucleation and growth, have been investigated. Preliminary numerical simulation results indicate that the damage modelling is capable to discriminate potential criticalities occurring in the SPR joining process opening the possibility for process parameters optimization and screening of candidate materials for optimum joint

  4. Self-piercing riveting - a review\\ud

    OpenAIRE

    Li, Dezhi; Chrysanthou, Andreas; Patel, Imran; Williams, Geraint J.

    2016-01-01

    Self-Piercing Riveting (SPR) is a cold mechanical joining process used to join two or more sheets of materials by driving a semitubular rivet piercing through the top sheet or the top and middle sheets and subsequently lock into the bottom sheet under the guidance of a suitable die. SPR was originated half century ago, but it only had significant progress in the last 25 years due to the requirement of joining lightweight materials, such as aluminium alloy structures, aluminium-steel structure...

  5. Lap Shear Testing of Candidate Radiator Panel Adhesives

    Science.gov (United States)

    Ellis, David; Briggs, Maxwell; McGowan, Randy

    2013-01-01

    During testing of a subscale radiator section used to develop manufacturing techniques for a full-scale radiator panel, the adhesive bonds between the titanium heat pipes and the aluminum face sheets failed during installation and operation. Analysis revealed that the thermal expansion mismatch between the two metals resulted in relatively large shear stresses being developed even when operating the radiator at moderate temperatures. Lap shear testing of the adhesive used in the original joints demonstrated that the two-part epoxy adhesive fell far short of the strength required. A literature review resulted in several candidate adhesives being selected for lap shear joint testing at room temperature and 398 K, the nominal radiator operating temperature. The results showed that two-part epoxies cured at room and elevated temperatures generally did not perform well. Epoxy film adhesives cured at elevated temperatures, on the other hand, did very well with most being sufficiently strong to cause yielding in the titanium sheet used for the joints. The use of an epoxy primer generally improved the strength of the joint. Based upon these results, a new adhesive was selected for the second subscale radiator section.

  6. Failure of aluminium self-piercing rivets: An experimental and numerical study

    International Nuclear Information System (INIS)

    Hoang, N.-H.; Hopperstad, O.S.; Langseth, M.; Westermann, I.

    2013-01-01

    Highlights: ► We investigated the fracture mechanism of AA7278-T6 aluminium self-piercing rivets. ► Fracture of AA 7278-T6 rivets during the riveting process is a complex phenomenon. ► Microstructure of AA7278-T6 has significant influence on the fracture mechanism. ► Increasing friction will change the deformation mode of the rivet. - Abstract: The present paper investigates the fracture mechanisms of AA7278-T6 aluminium self-piercing rivets under compression during the riveting process. First, a microstructure investigation was conducted to disclose the grain structure and the particle distribution of the extruded aluminium alloy. Transmission electron micrographs revealed precipitate free zones along grain boundaries. Uniaxial tensile tests in three different directions with respect to the extrusion direction revealed anisotropy of the alloy in strength and ductility and a change in fracture mode with tensile direction. The behaviour of the alloy under compression was studied experimentally using upsetting tests and self-piercing riveting tests. Micrographs of the deformed specimens provided insight into the influence of the microstructure on the deformation and fracture of the alloy under compression. Second, numerical analyses were carried out using a 2-D axisymmetric model in LS–DYNA in an attempt to investigate the role of different physical variables on the final failure of the rivet. The numerical results revealed that constituent particles, precipitate free zones, and friction between the rivet and plates are important for strain localisation and fracture in the rivet

  7. Inhomogeneous deformation of aluminum alloy AA-2219 Rivet heads during manufacturing-A case study

    International Nuclear Information System (INIS)

    Ahmad, S.; Subhani, T.; Haq, A.U.

    2006-01-01

    AA -2219 aluminum alloy wire of diameter 4mm was used for the manufacturing of rivets used in aerospace industry. The problem arose as the heads of many of the rivets were inhomogenously deformed during manufacturing and were declared reject by the customer. Investigation was carried out to uncover the cause of the problem and to find its solution. Chemical analysis and mechanical testing were performed to ascertain the chemical composition and mechanical properties of the rivet wire. Metallographic examination was also carried out to study the macro and micro structural details. Metallographic and mechanical results were also compared with that of qualified rivets. It was revealed that the rivet wire was not annealed after wire drawing process- and was in hardened state, which gave rise to a non-uniform plastic flow during manufacturing. The presence of second phase coherent precipitates increased the hardness and tensile strength of rivet wire and was found to be the possible cause of inhomogenously deformed rivet heads; which was rectified by partial annealing the rivet wire at suitable temperature. (author)

  8. 46 CFR 126.160 - Tests and inspections during repairs or alterations, or during riveting, welding, burning, or...

    Science.gov (United States)

    2010-10-01

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

  9. Transversely Compressed Bonded Joints

    DEFF Research Database (Denmark)

    Hansen, Christian Skodborg; Schmidt, Jacob Wittrup; Stang, Henrik

    2012-01-01

    The load capacity of bonded joints can be increased if transverse pressure is applied at the interface. The transverse pressure is assumed to introduce a Coulomb-friction contribution to the cohesive law for the interface. Response and load capacity for a bonded single-lap joint was derived using...

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

    Science.gov (United States)

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

    2016-02-01

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

  11. Even between-lap pacing despite high within-lap variation during mountain biking.

    Science.gov (United States)

    Martin, Louise; Lambeth-Mansell, Anneliese; Beretta-Azevedo, Liane; Holmes, Lucy A; Wright, Rachel; St Clair Gibson, Alan

    2012-09-01

    Given the paucity of research on pacing strategies during competitive events, this study examined changes in dynamic high-resolution performance parameters to analyze pacing profiles during a multiple-lap mountain-bike race over variable terrain. A global-positioning-system (GPS) unit (Garmin, Edge 305, USA) recorded velocity (m/s), distance (m), elevation (m), and heart rate at 1 Hz from 6 mountain-bike riders (mean±SD age=27.2±5.0 y, stature=176.8±8.1 cm, mass=76.3±11.7 kg, VO2max=55.1±6.0 mL·kg(-1)·min1) competing in a multilap race. Lap-by-lap (interlap) pacing was analyzed using a 1-way ANOVA for mean time and mean velocity. Velocity data were averaged every 100 m and plotted against race distance and elevation to observe the presence of intralap variation. There was no significant difference in lap times (P=.99) or lap velocity (P=.65) across the 5 laps. Within each lap, a high degree of oscillation in velocity was observed, which broadly reflected changes in terrain, but high-resolution data demonstrated additional nonmonotonic variation not related to terrain. Participants adopted an even pace strategy across the 5 laps despite rapid adjustments in velocity during each lap. While topographical and technical variations of the course accounted for some of the variability in velocity, the additional rapid adjustments in velocity may be associated with dynamic regulation of self-paced exercise.

  12. An evaluation of the lap-shear test for Sn-rich solder/Cu couples: Experiments and simulation

    Science.gov (United States)

    Chawla, N.; Shen, Y.-L.; Deng, X.; Ege, E. S.

    2004-12-01

    The lap-shear technique is commonly used to evaluate the shear, creep, and thermal fatigue behavior of solder joints. We have conducted a parametric experimental and modeling study, on the effect of testing and geometrical parameters on solder/copper joint response in lap-shear. It was shown that the farfield applied strain is quite different from the actual solder strain (measured optically). Subtraction of the deformation of the Cu substrate provides a reasonable approximation of the solder strain in the elastic regime, but not in the plastic regime. Solder joint thickness has a profound effect on joint response. The solder response moves progressively closer to “true” shear response with increasing joint thickness. Numerical modeling using finite-element analyses were performed to rationalize the experimental findings. The same lap-shear configuration was used in the simulation. The input response for solder was based on the experimental tensile test result on bulk specimens. The calculated shear response, using both the commonly adopted far-field measure and the actual shear strain in solder, was found to be consistent with the trends observed in the lap-shear experiments. The geometric features were further explored to provide physical insight into the problem. Deformation of the substrate was found to greatly influence the shear behavior of the solder.

  13. Lap belts and three-point belts.

    NARCIS (Netherlands)

    Kampen, L.T.B. van & Edelman, A.

    1975-01-01

    Results of the swov-accident investigation prove that if there are any differences in the effectiveness of lap belts and three-point belts, these are so small that they cannot form a basis for giving preference to one type over the other. Furthermore, in spite of the results of this investigation

  14. [Ultrabraid SUTURE WITH FOOTPRINT RIVET FOR ANTERIOR CRUCIATE LIGAMENT TIBIAL EMINENCE AVULSION FRACTURE IN ADOLESCENTS UNDER ARTHROSCOPY].

    Science.gov (United States)

    Liang, Jinying; Zheng, Jiapeng; Ll, Qiang; Zhong, Shuyu; Chen, Minzhen

    2015-06-01

    To investigate the clinical effects of the Ultrabraid suture with FOOTPRINT rivet by arthroscopic technique for the treatment of anterior cruciate ligament (ACL) tibial eminence avulsion fracture. Between May 2011 and December 2013, 19 adolescent patients with ACL tibial eminence avulsion fracture were treated with arthroscopic reduction and fixation by Ultrabraid sutures with FOOTPRINT rivet. There were 13 males and 6 females with an average age of 15.8 years (range, 8-18 years). The left knees were involved in 10 cases and the right knees in 9 cases. The injury causes included traffic accident injury in 8 cases, sport injury in 6 cases, and sprain injury in 5 cases. Three patients had old fractures, and the others had fresh fractures. The results of Lachman test and anterior drawer test were both positive. The International Knee Documentation Committee (IKDC) subject score was 54.2 ± 4.0. Based on Meyers-McKeever classification, there were 3 cases of type II, 10 cases of type III, and 6 cases of type IV. The operation time was 50-60 minutes (mean, 55.2 minutes). X-ray film showed satisfactory fracture reduction at 1 day after operation. Primary healing of incision was obtained with no infection. Eighteen patients were followed up for 1-3 years (mean, 1.7 years). All fractures healed with smooth joint surface on the X-ray film at 3 months after operation. The results of Lachman test and anterior drawer test were both negative in 17 cases, and the results was negative for anterior drawer test and was weakly positive for Lachman test in 1 case. The IKDC subject score was significantly improved to 96.1 ± 2.1 at last follow-up (t = 34.600, P = 0.000). It could achieve early restoration of knee joint function to treat the ACL tibial eminence avulsion fracture by arthroscopic technique of the Ultrabraid suture with FOOTPRINT rivet because of satisfactory reduction, reliable fixation, small wound, and early rehabilitation.

  15. Methods for Evaluating the Performance and Human Stress-Factors of Percussive Riveting

    Science.gov (United States)

    Ahn, Jonathan Y.

    The aerospace industry automates portions of their manufacturing and assembly processes. However, mechanics still remain vital to production, especially in areas where automated machines cannot fit, or have yet to match the quality of human craftsmanship. One such task is percussive riveting. Because percussive riveting is associated with a high risk of injury, these tool must be certified prior to release. The major contribution of this thesis is to develop a test bench capable of percussive riveting for ergonomic evaluation purposes. The major issues investigated are: (i) automate the tool evaluation method to be repeatable; (ii) demonstrate use of displacement and force sensors; and (iii) correlate performance and risk exposure of percussive tools. A test bench equipped with servomotors and pneumatic cylinders to control xyz-position of a rivet gun and bucking bar simultaneously, is used to explore this evaluation approach.

  16. Application of lap laser welding technology on stainless steel railway vehicles

    Science.gov (United States)

    Wang, Hongxiao; Wang, Chunsheng; He, Guangzhong; Li, Wei; Liu, Liguo

    2016-10-01

    Stainless steel railway vehicles with so many advantages, such as lightweight, antirust, low cost of maintenance and simple manufacturing process, so the production of high level stainless steel railway vehicles has become the development strategy of European, American and other developed nations. The current stainless steel railway vehicles body and structure are usually assembled by resistance spot welding process. The weak points of this process are the poor surface quality and bad airtight due to the pressure of electrodes. In this study, the partial penetration lap laser welding process was investigated to resolve the problems, by controlling the laser to stop at the second plate in the appropriate penetration. The lap laser welding joint of stainless steel railway vehicle car body with partial penetration has higher strength and surface quality than those of resistance spot welding joint. The biggest problem of lap laser welding technology is to find the balance of the strength and surface quality with different penetrations. The mechanism of overlap laser welding of stainless steel, mechanical tests, microstructure analysis, the optimization of welding parameters, analysis of fatigue performance, the design of laser welding stainless steel railway vehicles structure and the development of non-destructive testing technology were systematically studied before lap laser welding process to be applied in manufacture of railway vehicles. The results of the experiments and study show that high-quality surface state and higher fatigue strength can be achieved by the partial penetration overlap laser welding of the side panel structure, and the structure strength of the car body can be higher than the requirements of En12663, the standard of structural requirements of railway vehicles bodies. Our company has produced the stainless steel subway and high way railway vehicles by using overlap laser welding technology. The application of lap laser welding will be a big

  17. Instantaneous mechanical fastening of quasi-isotropic CFRP laminates by a self-piercing rivet

    OpenAIRE

    上田, 政人; 三宅, 崇太郎; 長谷川, 寛幸; 平野, 義鎭; Ueda, Masahito; Miyake, Sotaro; Hasegawa, Hiroyuki; Hirano, Yoshiyasu

    2012-01-01

    A modified self-piercing rivet (SPR) has been proposed to mechanically fasten CFRP laminates. The modified SPR consists of a rivet body and two flat washers. The two flat washers were used to suppress delamination in the CFRP laminates at the point of piercing. The advantages of the modified SPR for fastening CFRP laminates are instantaneous process time and low cost. Any pretreatments such as surface treatments or hole drilling are not required. In this study, the viability of the modified S...

  18. Seawater Durability of Nano-Montmorillonite Modified Single-Lap Joining Epoxy Composite Laminates

    OpenAIRE

    ULUS, Hasan; KAYBAL, Halil Burak; DEMİR, Okan; TATAR, Ahmet Caner; SENYURT, Muhammed Ali; AVCI, Ahmet

    2018-01-01

    The objective of this study was to investigate of nano-montmorillonite modified epoxy composite single-lap bonded joints, after being exposed to seawater immersion in order to understand the effect of seawater environment on their performance. To prepare the nano adhesives, nano montmorillonite (2 wt %) was incorporated into epoxy resin. Composite bonded specimens which manufactured with VARIM (Vacuum Assisted Resin Infusion Method) were prepared accordance with ASTM D5868-01 and immersed in ...

  19. Molten pool characterization of laser lap welded copper and aluminum

    Science.gov (United States)

    Xue, Zhiqing; Hu, Shengsun; Zuo, Di; Cai, Wayne; Lee, Dongkyun; Elijah, Kannatey-Asibu, Jr.

    2013-12-01

    A 3D finite volume simulation model for laser welding of a Cu-Al lap joint was developed using ANSYS FLUENT to predict the weld pool temperature distribution, velocity field, geometry, alloying element distribution and transition layer thickness—all key attributes and performance characteristics for a laser-welded joint. Melting and solidification of the weld pool was simulated with an enthalpy-porosity formulation. Laser welding experiments and metallographic examination by SEM and EDX were performed to investigate the weld pool features and validate the simulated results. A bowl-shaped temperature field and molten pool, and a unique maximum fusion zone width were observed near the Cu-Al interface. Both the numerical simulation and experimental results indicate an arch-shaped intermediate layer of Cu and Al, and a gradual transition of Cu concentration from the aluminum plate to the copper plate with high composition gradient. For the conditions used, welding with Cu on top was found to result in a better weld joint.

  20. Molten pool characterization of laser lap welded copper and aluminum

    International Nuclear Information System (INIS)

    Xue, Zhiqing; Hu, Shengsun; Zuo, Di; Cai, Wayne; Lee, Dongkyun; Elijah, Kannatey-Asibu Jr

    2013-01-01

    A 3D finite volume simulation model for laser welding of a Cu–Al lap joint was developed using ANSYS FLUENT to predict the weld pool temperature distribution, velocity field, geometry, alloying element distribution and transition layer thickness—all key attributes and performance characteristics for a laser-welded joint. Melting and solidification of the weld pool was simulated with an enthalpy-porosity formulation. Laser welding experiments and metallographic examination by SEM and EDX were performed to investigate the weld pool features and validate the simulated results. A bowl-shaped temperature field and molten pool, and a unique maximum fusion zone width were observed near the Cu–Al interface. Both the numerical simulation and experimental results indicate an arch-shaped intermediate layer of Cu and Al, and a gradual transition of Cu concentration from the aluminum plate to the copper plate with high composition gradient. For the conditions used, welding with Cu on top was found to result in a better weld joint. (paper)

  1. Double fillet lap of laser welding of thin sheet AZ31B Mg alloy

    Science.gov (United States)

    Ishak, Mahadzir; Salleh, M. N. M.

    2018-05-01

    In this paper, we describe the experimental laser welding of thin sheet AZ31B using double fillet lap joint method. Laser welding is capable of producing high quality weld seams especially for small weld bead on thin sheet product. In this experiment, both edges for upper and lower sheets were subjected to the laser beam from the pulse wave (PW) mode of fiber laser. Welded sample were tested their joint strength by tensile-shear strength method and the fracture loads were studied. Strength for all welded samples were investigated and the effect of laser parameters on the joint strength and appearances were studied. Pulsed energy (EP) from laser process give higher effect on joint strength compared to the welding speed (WS) and angle of irradiation (AOI). Highest joint strength was possessed by sample with high EP with the same value of WS and AOI. The strength was low due to the crack defect at the centre of weld region.

  2. Role of heat equation in lap joint for welding process

    Science.gov (United States)

    Kumar, P.; Rohit, Sooraj

    2017-07-01

    Welding is predominantly used in industrial purposes and growth in their industry, which gives exact welding and more efficient. The major advantage of using this welding technique at initial stage it takes very low heat to weld the portion and gives a good result of low distortion in modules. In this context, two dissimilar metals copper and nickel are chosen for analysis in tungsten inert gas welding (TIG) in which length is 300 mm and breadth is 100 mm thickness 15 mm welded at room temperature a welded portion zone is formed simulation analysis has done on CATIA® and ANSYS®and MATLAB® code is generated for calculating temperatures at each node to calculate temperature at each node a new technique is used tri-diagonal matrix algorithm is used (TDMA) Steady state one dimension heat is calculated results compared between simulation analysis and analytical analysis temperature at each node is calculated both the temperatures are equal with error.

  3. Assessment of the RIVET fixation system for cranioplasty using the pull-out technique.

    Science.gov (United States)

    Sakamoto, Yoshiaki; Minabe, Toshiharu; Kato, Tatsuya; Kishi, Kazuo

    2015-03-01

    Cranioplasty using custom-made hydroxyapatite (HAP) ceramic implants is a common procedure to repair skull defects. However, commercially available titanium screws are only minimally stabilized due to characteristic brittleness. We developed the RIVET technique which involves fixing a bioabsorbable plate atop a HAP block using bioabsorbable screws extending beyond both layers, and evaluated fixation strength using the pull-out test and microtomography. Three experimental conditions were compared: a non-RIVET group, RIVET group, and dry skull control group. Pull-out strength significantly differed across groups (non-RIVET group, 1.33 ± 1.21 kgf; RIVET group, 4.46 ± 0.84 kgf; and control group, 6.99 ± 1.14 kgf, P uses commercially available absorbable plate and screws, and thus can be used widely in clinical applications involving HAP blocks with different porosities and thicknesses. Copyright © 2014 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  4. Determination of crack size around rivet hole through neural network using ultrasonic Lamb wave

    International Nuclear Information System (INIS)

    Choi, Sang Woo; Lee, Joon Hyun

    1998-01-01

    Rivets are typical structural features that are potential initiation sites for fatigue crack due to combination of local stress concentration around rivet hole and moisture trapping. For the viewpoint of structural assurance, it is crucial to evaluate the size of crack around rivets by appropriate nondestructive techniques. Guided waves, which direct wave energy along the plate, carry information about the material in their path and offer a potentially more efficient tool for nondestructive inspection of structural material. Neural network that is considered to be the most suitable for pattern recognition and has been used by researchers in NDE field to classify different types of flaws and flaw size. In this study, crack size determination around rivet through a neural network based on the back-propagation algorithm has been done by extracting some feature from time-domain waveforms of ultrasonic Lamb wave for Al 2024-T3 skin panel of aircraft. Special attention was paid to reduce the coupling effect between transducer and specimen by extracting some features related to only time component data in ultrasonic waveform. It was demonstrated clearly that features extraction based on time component data of the time-domain waveform of Lamb wave was very useful to determine crack size initiated from rivet hole through neural network.

  5. New design deforming controlling system of the active stressed lap

    Science.gov (United States)

    Ying, Li; Wang, Daxing

    2008-07-01

    A 450mm diameter active stressed lap has been developed in NIAOT by 2003. We design a new lap in 2007. This paper puts on emphases on introducing the new deforming control system of the lap. Aiming at the control characteristic of the lap, a new kind of digital deforming controller is designed. The controller consists of 3 parts: computer signal disposing, motor driving and force sensor signal disposing. Intelligent numeral PID method is applied in the controller instead of traditional PID. In the end, the result of new deformation are given.

  6. Joining aluminum to titanium alloy by friction stir lap welding with cutting pin

    International Nuclear Information System (INIS)

    Wei, Yanni; Li, Jinglong; Xiong, Jiangtao; Huang, Fu; Zhang, Fusheng; Raza, Syed Hamid

    2012-01-01

    Aluminum 1060 and titanium alloy Ti–6Al–4V plates were lap joined by friction stir welding. A cutting pin of rotary burr made of tungsten carbide was employed. The microstructures of the joining interface were observed by scanning electron microscopy. Joint strength was evaluated by a tensile shear test. During the welding process, the surface layer of the titanium plate was cut off by the pin, and intensively mixed with aluminum situated on the titanium plate. The microstructures analysis showed that a visible swirl-like mixed region existed at the interface. In this region, the Al metal, Ti metal and the mixed layer of them were all presented. The ultimate tensile shear strength of joint reached 100% of 1060Al that underwent thermal cycle provided by the shoulder. - Highlights: ► FSW with cutting pin was successfully employed to form Al/Ti lap joint. ► Swirl-like structures formed due to mechanical mixing were found at the interface. ► High-strength joints fractured at Al suffered thermal cycle were produced.

  7. Application of the virtual crack closure technique to calculate stress intensity factors for through cracks with an oblique elliptical crack front

    NARCIS (Netherlands)

    Fawaz, S.

    1998-01-01

    Fractographic observations on fatigue tested 2024 T3 clad aluminium riveted lap-splice joints indicate oblique fronts after the initial surface or corner crack at a rivet hole has penetrated through the sheet thichness. No stress intensity factor solutions are available for this geometry subjected

  8. Joint resistance measurements of pancake and terminal joints for JT-60SA EF coils

    Energy Technology Data Exchange (ETDEWEB)

    Obana, Tetsuhiro, E-mail: obana.tetsuhiro@LHD.nifs.ac.jp [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Takahata, Kazuya; Hamaguchi, Shinji; Mito, Toshiyuki; Imagawa, Shinsaku [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan); Kizu, Kaname; Murakami, Haruyuki; Yoshida, Kiyoshi [Japan Atomic Energy Agency, 801-1 Mukoyama, Naka, Ibaraki 311-0193 (Japan)

    2013-11-15

    Highlights: • To evaluate the joint fabrication technology for the JT-60SA EF coils, joint resistance measurements were conducted with a joint sample. • The joint sample was composed of pancake and terminal joints. • The measurements demonstrated that both joints fulfilled the design requirement. • Considering the measurements, the characteristics of both joints were investigated using an analytical model that represents the joints. -- Abstract: To evaluate the joint fabrication technology for the JT-60SA EF coils, joint resistance measurements were conducted using a sample consisting of pancake and terminal joints. Both joints are shake-hands lap joints composed of cable-in-conduit conductors and a pure copper saddle-shaped spacer. The measurements demonstrated that both joints fulfilled the design requirement. Considering these measurements, the characteristics of both joints were investigated using analytical models that represent the joints. The analyses indicated that the characteristics of the conductors used in the joints affect the characteristics of the joints.

  9. Machine Shop I. Learning Activity Packets (LAPs). Section C--Hand and Bench Work.

    Science.gov (United States)

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains two learning activity packets (LAPs) for the "hand and bench work" instructional area of a Machine Shop I course. The two LAPs cover the following topics: hand and bench work and pedestal grinder. Each LAP contains a cover sheet that describes its purpose, an introduction, and the tasks included in the LAP;…

  10. Machine Shop I. Learning Activity Packets (LAPs). Section D--Power Saws and Drilling Machines.

    Science.gov (United States)

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains two learning activity packets (LAPs) for the "power saws and drilling machines" instructional area of a Machine Shop I course. The two LAPs cover the following topics: power saws and drill press. Each LAP contains a cover sheet that describes its purpose, an introduction, and the tasks included in the LAP; learning…

  11. Machine Shop I. Learning Activity Packets (LAPs). Section A--Orientation.

    Science.gov (United States)

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains two learning activity packets (LAPs) for the "orientation and safety" instructional area of a Machine Shop I course. The two LAPs cover the following topics: orientation and general shop safety. Each LAP contains a cover sheet that describes its purpose, an introduction, and the tasks included in the LAP; learning…

  12. Nondestructive evaluation algorithm of fatigue cracks and far-side corrosion around a rivet fastener in multi-layered structures

    Energy Technology Data Exchange (ETDEWEB)

    Le, Min Hhuy; Kim, Jung Min [Research Center for IT-based Real Time NDT for Nano-Damage Tolerance, Chosun University, Gwangju (Korea, Republic of); Kim, Sejin; Wang, Dabin [Dept. of Control and Instrumentation Engineering, Graduate School, Chosun University, Gwangju (Korea, Republic of); Hwang, Young Ha [Avionics System Technology Center, KITECH, Youngcheon (Korea, Republic of)

    2016-09-15

    This research proposes a nondestructive inspection system for inspecting and localizing corrosion and fatigue cracks around rivets in air-intake structures. The system uses 64 InSb Hall sensor elements arrayed at a high spatial interval of 0.52 mm. Rivet detection and damage detection algorithms will be proposed. Analysis of the receiver operating characteristic curve and Probability of detection (POD) will be carried out to evaluate the performance of the system and detection algorithms. Artificial corrosion around a rivet with a minimum volume of 11.02 mm{sup 3} could be detected with 90/95% POD and artificial fatigue crack with minimum length of 2.95 mm from rivet body.

  13. Double-Lap Shear Test For Honeycomb Core

    Science.gov (United States)

    Nettles, Alan T.; Hodge, Andrew J.

    1992-01-01

    Double-lap test measures shear strength of panel made of honeycomb core with 8-ply carbon-fiber/epoxy face sheets. Developed to overcome three principal disadvantages of prior standard single-lap shear test: specimen had to be more than 17 in. long; metal face sheets had to be used; and test introduced torque, with consequent bending and peeling of face sheets and spurious tensile or compressive loading of honeycomb.

  14. Lap shear strength and healing capability of self-healing adhesive containing epoxy/mercaptan microcapsules

    Energy Technology Data Exchange (ETDEWEB)

    Ghazali, Habibah; Ye, Lin [Centre for Advanced Materials Technology (CAMT), School of Aerospace, Mechanical and Mechatronic Engineering, The University of Sydney, NSW 2006 (Australia); Zhang, Ming-Qiu [Key Laboratory of Polymeric Composite and Functional Materials of Ministry of Education, Zhongshan University, Guangzhou 510275 (China)

    2016-03-09

    The aim of this work is to develop a self-healing polymeric adhesive formulation with epoxy/mercaptan microcapsules. Epoxy/mercaptan microcapsules were dispersed into a commercialize two-part epoxy adhesive for developing self-healing epoxy adhesive. The influence of different content of microcapsules on the shear strength and healing capability of epoxy adhesive were investigated using single-lap-joints with average thickness of adhesive layer of about 180 µm. This self-healing adhesive was used in bonding of 5000 series aluminum alloys adherents after mechanical and alkaline cleaning surface treatment. The adhesion strength was measured and presented as function of microcapsules loading. The results indicated that the virgin lap shear strength was increased by about 26% with addition of 3 wt% of self-healing microcapsules. 12% to 28% recovery of the shear strength is achieved after self-healing depending on the microcapsules content. Scanning electron microscopy was used to study fracture surface of the joints. The self-healing adhesives exhibit recovery of both cohesion and adhesion properties with room temperature healing.

  15. Lap shear strength and healing capability of self-healing adhesive containing epoxy/mercaptan microcapsules

    International Nuclear Information System (INIS)

    Ghazali, Habibah; Ye, Lin; Zhang, Ming-Qiu

    2016-01-01

    The aim of this work is to develop a self-healing polymeric adhesive formulation with epoxy/mercaptan microcapsules. Epoxy/mercaptan microcapsules were dispersed into a commercialize two-part epoxy adhesive for developing self-healing epoxy adhesive. The influence of different content of microcapsules on the shear strength and healing capability of epoxy adhesive were investigated using single-lap-joints with average thickness of adhesive layer of about 180 µm. This self-healing adhesive was used in bonding of 5000 series aluminum alloys adherents after mechanical and alkaline cleaning surface treatment. The adhesion strength was measured and presented as function of microcapsules loading. The results indicated that the virgin lap shear strength was increased by about 26% with addition of 3 wt% of self-healing microcapsules. 12% to 28% recovery of the shear strength is achieved after self-healing depending on the microcapsules content. Scanning electron microscopy was used to study fracture surface of the joints. The self-healing adhesives exhibit recovery of both cohesion and adhesion properties with room temperature healing.

  16. Influence of tool geometry and rotational speed on mechanical properties and defect formation in friction stir lap welded 5456 aluminum alloy sheets

    International Nuclear Information System (INIS)

    Salari, Emad; Jahazi, Mohammad; Khodabandeh, Alireza; Ghasemi-Nanesa, Hadi

    2014-01-01

    Highlights: • Successful lap joint friction stir welding of AA5456 with two different tempers. • New stepped conical threaded pin for FSW of lap joints is introduced. • Investigated interactions between tool geometry and mechanical properties. • Microstructure and fracture surface analysis of dissimilar lap welds. - Abstract: Friction stir welding of AA5456 aluminum alloy in lap joint configuration is with two different tempers, T321 and O, and different thicknesses, 5 mm and 2.5 mm was investigated. The influences of tool geometry and various rotational speeds on macrostructure, microstructure and joint strength are presented. Specifically, four different tool pin profiles (a conical thread pin, a cylindrical–conical thread pin, a stepped conical thread pin and Flared Triflute pin tool) and two rotational speeds, 600 and 800 rpm, were used. The results indicated that, tool geometry influences significantly material flow in the nugget zone and accordingly control the weld mechanical properties. Of particular interest is the stepped conical threaded pin, which is introduced for the first time in the present investigation. Scanning electron microscopy investigation of the fracture location of samples was carried out and the findings correlated with tool geometry features and their influences on material flow and tension test results. The optimum microstructure and mechanical properties were obtained for the joints produced with the stepped conical thread pin profile and rotational speed of 600 rpm. The characteristics of the nugget zone microstructure, hooking height, and fracture location of the weld joints were used as criteria to quantify the influence of processing conditions on joint performance and integrity. The results are interpreted in the framework of physical metallurgy properties and compared with published literature

  17. Stress analysis of fatigue cracks in mechanically fastened joints : An analytical and experimental investigation

    NARCIS (Netherlands)

    De Rijck, J.J.M.

    2005-01-01

    The two historical fuselage failures, Comet in 1954 and Aloha in 1988, illustrate that similar accidents must be avoided which requires a profound understanding of the fatigue mechanisms involved, including analytical models to predict the fatigue behavior of riveted joints of a fuselage structure.

  18. Fatigue and Damage Tolerance of Friction Stir Welded Joints for Aerospace Applications

    NARCIS (Netherlands)

    Lemmen, H.J.K.

    2010-01-01

    Friction stir welding is a young welding process with high potential to replace riveted joints in aerospace structures like the fuselage. Friction stir welding is a robust process and capable of welding high strength aluminum alloys. Therefore it can lead to both costs and weight savings. To

  19. Analysis for Behavior of Reinforcement Lap Splices in Deep Beams

    Directory of Open Access Journals (Sweden)

    Ammar Yaser Ali

    2018-03-01

    Full Text Available The present study includes an experimental and theoretical investigation of reinforced concrete deep beams containing tensile reinforcement lap splices at constant moment zone under static load. The study included two stages: in the first one, an experimental work included testing of eight simply supported RC deep beams having a total length (L = 2000 mm, overall depth (h= 600 mm and width (b = 150 mm. The tested specimens were divided into three groups to study the effect of main variables: lap length, location of splice, internal confinement (stirrups and external confinement (strengthening by CFRP laminates. The experimental results showed that the use of CFRP as external strengthening in deep beam with lap spliced gives best behavior such as increase in stiffness, decrease in deflection, delaying the cracks appearance and reducing the crack width. The reduction in deflection about (14-21 % than the unstrengthened beam and about (5-14 % than the beam with continuous bars near ultimate load. Also, it was observed that the beams with unstrengthened tensile reinforcement lap splices had three types of cracks: flexural, flexural-shear and splitting cracks while the beams with strengthened tensile reinforcement lap splices or continuous bars don’t observe splitting cracks. In the second stage, a numerical analysis of three dimensional finite element analysis was utilized to explore the behavior of the RC deep beams with tensile reinforcement lap splices, in addition to parametric study of many variables. The comparison between the experimental and theoretical results showed reasonable agreement. The average difference of the deflection at service load was less than 5%.

  20. Ability Of Mathematical Reasoning in SMK 10th Grade with LAPS- Heuristic using Performance Assessment

    OpenAIRE

    Aulia Nur Arivina; Masrukan Masrukan; Ardhi Prabowo

    2017-01-01

    The purposes of this research are: (1) Test the learning with LAPS-Heuristic model using performance assessment on 10th grade of Trigonometry material is complete, (2) to test the difference of students' mathematical reasoning ability on 10th grade of Trigonometry material between the learning model of LAPS-Heuristic using performance assessment, LAPS-Heuristic learning model with Expository learning model, (3) test the ability of mathematical reasoning with learning model of LAPS-Heuristik o...

  1. 120-MM Target Practice Cone Stabilized Discarding Sabot with Tracer (TPCSDS-T) M865 (E3) Rework Report (Pop-Rivet Design)

    National Research Council Canada - National Science Library

    Donlon, Francis

    2002-01-01

    .... The team came up with three different solutions for field fix rework: (a) pop rivets; (b) foam fill, and (c) pool of epoxy. The foam design was the number one choice of the team, but the pop rivets had lower overall risk...

  2. Auto Mechanics I. Learning Activity Packets (LAPs). Section E--Brakes.

    Science.gov (United States)

    Oklahoma State Board of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains two learning activity packets (LAPs) that outline the study activities for the "brakes" instructional area for an Auto Mechanics I course. The two LAPs cover the following topics: brake systems and power disc brakes. Each LAP contains a cover sheet that describes its purpose, an introduction, and the tasks included…

  3. Effect of lapping slurry on critical cutting depth of spinel

    International Nuclear Information System (INIS)

    Wang, Zhan-kui; Wang, Zhuan-kui; Zhu, Yong-wei; Su, Jian-xiu

    2015-01-01

    Highlights: • Measured spinel wafers’ hardness and crack length in different slurries. • Evaluated the softened layer thickness in different slurries. • Discussed the effect of slurries on critical cutting depth of spinel. - Abstract: The critical cutting depth for lapping process is very important because it influences the mode of material removal. In this paper, a serial of microscopic indentation experiments were carried out for measuring spinel wafers’ hardness and crack length in different lapping slurries. Their critical cutting depth and fracture toughness were calculated. X-ray photoelectron spectroscopy (XPS) was also employed to study the surface chemical composition and softened layer thickness of wafers in different slurries. Experimental results indicate that the softened layers of spinel wafers are formed due to the corrosion of lapping slurries, which leads to a lower hardness and a larger fracture toughness of samples, and increases the critical cutting depth. Among them, the critical cutting depth in ethylene glycol solution is the largest and up to 21.8 nm. The increase of critical cutting depth is helpful to modify the surface quality of the work-piece being lapped via ductile removal mode instead of brittle fracture mode

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

    International Nuclear Information System (INIS)

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

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Schaller, Benoit [Department of Cranio-Maxillofacial Surgery, Inselspital, Bern University Hospital and University of Bern, CH-3010 Bern (Switzerland); National Dental Centre Singapore, 168938 (Singapore); Saulacic, Nikola [Department of Cranio-Maxillofacial Surgery, Inselspital, Bern University Hospital and University of Bern, CH-3010 Bern (Switzerland); Beck, Stefan, E-mail: SBECK2@its.jnj.com [Synthes Biomaterials, Eimattstr. 3, CH-4436 Oberdorf (Switzerland); Imwinkelried, Thomas [RMS Foundation, Bischmattstr. 12, CH-2544 Bettlach (Switzerland); Goh, Bee Tin [National Dental Centre Singapore, 168938 (Singapore); Nakahara, Ken [Department of Cranio-Maxillofacial Surgery, Inselspital, Bern University Hospital and University of Bern, CH-3010 Bern (Switzerland); Hofstetter, Willy [Department of Clinical Research, University of Bern, CH-3010 Bern (Switzerland); Iizuka, Tateyuki [Department of Cranio-Maxillofacial Surgery, Inselspital, Bern University Hospital and University of Bern, CH-3010 Bern (Switzerland)

    2016-12-01

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

  6. The tensile strength of mechanical joint prototype of lontar fiber composite

    Science.gov (United States)

    Bale, Jefri; Adoe, Dominggus G. H.; Boimau, Kristomus; Sakera, Thomas

    2018-03-01

    In the present study, an experimental activity has been programmed to investigate the effect of joint prototype configuration on tensile strength of lontar (Borassus Flabellifer) fiber composite. To do so, a series of tests were conducted to establish the tensile strength of different joint prototype configuration specimen of lontar fiber composite. In addition, post observation of macroscope was used to map damage behavior. The analysis of lontar fiber composite is a challenge since the material has limited information than others natural fiber composites materials. The results shown that, under static tensile loading, the tensile strength of 13 MPa produced by single lap joint of lontar fiber composite is highest compare to 11 MPa of tensile strength generated by step lap joint and double lap joint where produced the lowest tensile strength of 6 MPa. It is concluded that the differences of tensile strength depend on the geometric dimensions of the cross-sectional area and stress distribution of each joint prototype configuration.

  7. Combination of TB lymphadenitis and metastatic LAP in breast cancer

    Directory of Open Access Journals (Sweden)

    Abdolhassan Talaiezadeh

    2015-06-01

    Full Text Available Tuberculosis (TB may present as pulmonary and extra-pulmonary. TB lymphadenitis is the most common presentation of extra-pulmonary TB. TB lymphadenitis should be taken into account in the differential diagnosis of different disorders such as metastatic lymphadenopathy. The reported patient was a 65-year-old lady with breast cancer and conglomerated and matted axillary lymphadenopathy who received chemotherapy. She presented with more extensive axillary LAP contrary to our expectation. Modified radical mastectomy was done and pathology analysis reported TB lymphadenitis associated with metastatic LAP. Under cover of anti-TB therapy adjuvant chemoradiation therapy was started. Accordingly, we recommend TB be ruled out in every patient who needs chemotherapy in the endemic region because chemotherapy may cause the extension of TB in the body.

  8. Self pierce riveting in the car body construction; Stanznieten im Karosserieleichtbau

    Energy Technology Data Exchange (ETDEWEB)

    Ahlers-Hestermann, G. [Boellhoff GmbH, Bielefeld (Germany)

    1999-09-01

    As an alterantive to spotwelding, self pierce riveting becomes more and more important in light weight automotive body constructions. The difficulties or impossibility of spotwelding Aluminium and High Tensile Strength Steel or material mixtures accelerated this development. Even plastic material can be joined to metal. Important mechanical properties such as fatigue and crash behaviour are improved. Costs are at the same level. Two examples of body parts in aluminium (Audi A6 bonnet and BMW 3 series front end) are described. (orig.) [German] Als Alternative zum Punktschweissen setzt sich das Stanznieten mit Halbhohlniet im Karosserieleichtbau mehr und mehr durch. Mit diesem Verfahren koennen verschiedene Materialen mit bis zu vier Lagen sicher verbunden werden. Dieser Beitrag der Boellhoff GmbH stellt das Verfahren vor und berichtet ueber zwei Beispiele aus der Praxis. (orig.)

  9. INFORMATION FOR USERS OF NUTS, BOLTS, SCREWS, NAILS AND RIVETS (SCEM GROUP 47)

    CERN Multimedia

    Logistics Group

    2002-01-01

    We should like to remind users that, since the closure of the self-service stores, nuts, bolts, screws, nails and rivets (Group 47 of the Stores Catalogue) can be obtained, in smaller packages than via EDH, from the 'Emergency Counter' in the Central Stores (Building 73, R-002) upon presentation of a duly completed hard-copy Materials Request form. The 'Emergency Counter' is open Mondays to Fridays from 7.30 a.m. to 11.50 a.m. and from 1.00 p.m. to 4.20 p.m. Information concerning the available packages can be found under the appropriate SCEM reference number in the Stores Catalogue. Logistics Group SPL Division

  10. Experimental Investigation into Vibration Characteristics for Damage Minimization in a Lapping Process

    Directory of Open Access Journals (Sweden)

    J. Suwatthikul

    2016-01-01

    Full Text Available Lapping machines are used in a hard disk rough lapping process where a workpiece (a wafer row bar is locked with a robot arm and rubbed on a lap plate. In this process, the lap plate’s condition and lifetime are among important concerned factors. The lifetime can be too short due to the plate being accidentally scratched by the workpiece during lapping. This problem leads to undesired consequences such as machine downtime and excessive plate material usage. This paper presents an experimental investigation into vibration characteristics of passed and failed lapping scenarios and discusses a potential solution to minimize the serious damage so-called “plate scratch” which intermittently occurs in such process. The experimental results show that, by in situ monitoring vibration and utilizing artificial intelligence, damage minimization can be possible.

  11. Design of Helical Self-Piercing Rivet for Joining Aluminum Alloy and High-Strength Steel Sheets

    Energy Technology Data Exchange (ETDEWEB)

    Kim, W. Y.; Kim, D. B.; Park, J. G; Kim, D. H.; Kim, K. H.; Lee, I. H.; Cho, H. Y. [Chungbuk National University, Cheongju (Korea, Republic of)

    2014-07-15

    A self-piercing rivet (SPR) is a mechanical component for joining dissimilar material sheets such as those of aluminum alloy and steel. Unlike conventional rivets, the SPR directly pierces sheets without the need for drilling them beforehand. However, the regular SPR can undergo buckling when it pierces a high-strength steel sheet, warranting the design of a helical SPR. In this study, the joining and forging processes using the helical SPR were simulated using the commercial FEM code, DEFORM-3D. High-tensile-strength steel sheets of different strengths were joined with aluminum alloy sheets using the designed helical SPR. The simulation results were found to agree with the experimental results, validating the optimal design of a helical SPR that can pierce high-strength steel sheets.

  12. Design of Helical Self-Piercing Rivet for Joining Aluminum Alloy and High-Strength Steel Sheets

    International Nuclear Information System (INIS)

    Kim, W. Y.; Kim, D. B.; Park, J. G; Kim, D. H.; Kim, K. H.; Lee, I. H.; Cho, H. Y.

    2014-01-01

    A self-piercing rivet (SPR) is a mechanical component for joining dissimilar material sheets such as those of aluminum alloy and steel. Unlike conventional rivets, the SPR directly pierces sheets without the need for drilling them beforehand. However, the regular SPR can undergo buckling when it pierces a high-strength steel sheet, warranting the design of a helical SPR. In this study, the joining and forging processes using the helical SPR were simulated using the commercial FEM code, DEFORM-3D. High-tensile-strength steel sheets of different strengths were joined with aluminum alloy sheets using the designed helical SPR. The simulation results were found to agree with the experimental results, validating the optimal design of a helical SPR that can pierce high-strength steel sheets

  13. Role of LAP+CD4+ T cells in the tumor microenvironment of colorectal cancer.

    Science.gov (United States)

    Zhong, Wu; Jiang, Zhi-Yuan; Zhang, Lei; Huang, Jia-Hao; Wang, Shi-Jun; Liao, Cun; Cai, Bin; Chen, Li-Sheng; Zhang, Sen; Guo, Yun; Cao, Yun-Fei; Gao, Feng

    2017-01-21

    To investigate the abundance and potential functions of LAP + CD4 + T cells in colorectal cancer (CRC). Proportions of LAP + CD4 + T cells were examined in peripheral blood and tumor/paratumor tissues of CRC patients and healthy controls using flow cytometry. Expression of phenotypic markers such as forkhead box (Fox)p3, cytotoxic T-lymphocyte-associated protein (CTLA)-4, chemokine CC receptor (CCR)4 and CCR5 was measured using flow cytometry. LAP - CD4 + and LAP + CD4 + T cells were isolated using a magnetic cell-sorting system and cell purity was analyzed by flow cytometry. Real-time quantitative polymerase chain reaction was used to measure expression of cytokines interleukin (IL)-10 and transforming growth factor (TGF)-β. The proportion of LAP + CD4 + T cells was significantly higher in peripheral blood from patients (9.44% ± 3.18%) than healthy controls (1.49% ± 1.00%, P CD4 + T cells was significantly higher in tumor tissues (11.76% ± 3.74%) compared with paratumor tissues (3.87% ± 1.64%, P CD4 + T cells and TNM stage ( P cell sorting gave an overall enrichment of LAP + CD4 + T cells (95.02% ± 2.87%), which was similar for LAP - CD4 + T cells (94.75% ± 2.76%). In contrast to LAP - CD4 + T cells, LAP + CD4 + T cells showed lower Foxp3 expression but significantly higher levels of CTLA-4, CCR4 and CCR5 ( P CD4 + T cells expressed significantly larger amounts of IL-10 and TGF-β but lower levels of IL-2, IL-4, IL-17 and interferon-γ, compared with LAP - CD4 + T cells. LAP + CD4 + T cells accumulated in the tumor microenvironment of CRC patients and were involved in immune evasion mediated by IL-10 and TGF-β.

  14. Behaviour and Modelling of Self-piercing Screw and Self-piercing Rivet Connections: An Experimental and Numerical Investigation

    OpenAIRE

    Sønstabø, Johan Kolstø; Holmstrøm, Petter Henrik

    2013-01-01

    Accurate and reliable models of connections are essential for the design of aluminium parts in cars. Today, there exist a few models customized for self-piercing rivets (SPR), but none for self-piercing screws (SPS). This thesis presents an experimental and numerical study on the behaviour of SPR and SPS connections for different loading situations. For the rolled base material, AA6016 in the T4 condition, uniaxial tension, plane strain tension and in-plane single shear tests were performe...

  15. Edge effect modeling and experiments on active lap processing.

    Science.gov (United States)

    Liu, Haitao; Wu, Fan; Zeng, Zhige; Fan, Bin; Wan, Yongjian

    2014-05-05

    Edge effect is regarded as one of the most difficult technical issues for fabricating large primary mirrors, especially for large polishing tools. Computer controlled active lap (CCAL) uses a large size pad (e.g., 1/3 to 1/5 workpiece diameters) to grind and polish the primary mirror. Edge effect also exists in the CCAL process in our previous fabrication. In this paper the material removal rules when edge effects happen (i.e. edge tool influence functions (TIFs)) are obtained through experiments, which are carried out on a Φ1090-mm circular flat mirror with a 375-mm-diameter lap. Two methods are proposed to model the edge TIFs for CCAL. One is adopting the pressure distribution which is calculated based on the finite element analysis method. The other is building up a parametric equivalent pressure model to fit the removed material curve directly. Experimental results show that these two methods both effectively model the edge TIF of CCAL.

  16. Mechanistic Features of Nanodiamonds in the Lapping of Magnetic Heads

    Directory of Open Access Journals (Sweden)

    Xionghua Jiang

    2014-01-01

    Full Text Available Nanodiamonds, which are the main components of slurry in the precision lapping process of magnetic heads, play an important role in surface quality. This paper studies the mechanistic features of nanodiamond embedment into a Sn plate in the lapping process. This is the first study to develop mathematical models for nanodiamond embedment. Such models can predict the optimum parameters for particle embedment. From the modeling calculations, the embedded pressure satisfies p0=3/2·W/πa2 and the indentation depth satisfies δ=k1P/HV. Calculation results reveal that the largest embedded pressure is 731.48 GPa and the critical indentation depth δ is 7 nm. Atomic force microscopy (AFM, scanning electron microscopy (SEM, and Auger electron spectroscopy (AES were used to carry out surface quality detection and analysis of the disk head. Both the formation of black spots on the surface and the removal rate have an important correlation with the size of nanodiamonds. The results demonstrate that an improved removal rate (21 nm·min−1 can be obtained with 100 nm diamonds embedded in the plate.

  17. Mechanistic features of nanodiamonds in the lapping of magnetic heads.

    Science.gov (United States)

    Jiang, Xionghua; Chen, Zhenxing; Wolfram, Joy; Yang, Zhizhou

    2014-01-01

    Nanodiamonds, which are the main components of slurry in the precision lapping process of magnetic heads, play an important role in surface quality. This paper studies the mechanistic features of nanodiamond embedment into a Sn plate in the lapping process. This is the first study to develop mathematical models for nanodiamond embedment. Such models can predict the optimum parameters for particle embedment. From the modeling calculations, the embedded pressure satisfies p 0 = (3/2) · (W/πa (2)) and the indentation depth satisfies δ = k1√P/HV. Calculation results reveal that the largest embedded pressure is 731.48 GPa and the critical indentation depth δ is 7 nm. Atomic force microscopy (AFM), scanning electron microscopy (SEM), and Auger electron spectroscopy (AES) were used to carry out surface quality detection and analysis of the disk head. Both the formation of black spots on the surface and the removal rate have an important correlation with the size of nanodiamonds. The results demonstrate that an improved removal rate (21 nm · min(-1)) can be obtained with 100 nm diamonds embedded in the plate.

  18. Ability Of Mathematical Reasoning in SMK 10th Grade with LAPS- Heuristic using Performance Assessment

    Directory of Open Access Journals (Sweden)

    Aulia Nur Arivina

    2017-11-01

    Full Text Available The purposes of this research are: (1 Test the learning with LAPS-Heuristic model using performance assessment on 10th grade of Trigonometry material is complete, (2 to test the difference of students' mathematical reasoning ability on 10th grade of Trigonometry material between the learning model of LAPS-Heuristic using performance assessment, LAPS-Heuristic learning model with Expository learning model, (3 test the ability of mathematical reasoning with learning model of LAPS-Heuristik on Trigonometry material of SMK on 10th grade using performance assessment is increase. This is a quantitative research. The population is students of 10th grade of SMK 10 Semarang academic year 2016/2017 and the subject of research is selected by clustering random sampling. The results show that (1 Learning by model LAPS-Heuristic using performance assessment on 10th grade of Trigonometry material is complete (2 there are differences in students' mathematical reasoning ability on 10th grade of Trigonometry materials between LAPS-Heuristic learning model using performance assessment, LAPS-Heuristic learning model, and Expository learning model, (3 The ability of mathematical reasoning with learning model of LAPS-Heuristic on Trigonometry material of SMK class X using performance assessment increased.

  19. Determination of face validity for the Simbionix LAP mentor virtual reality training module

    NARCIS (Netherlands)

    Ayodeji, I. D.; Schijven, M. P.; Jakimowicz, J. J.

    2006-01-01

    This study determines the expert and referent face validity of LAP Mentor, the first procedural virtual-reality (VR) trainer. After a hands-on introduction to the simulator a questionnaire was administered to 49 participants (21 expert laparoscopists and 28 novices). There was a consensus on LAP

  20. Learning Activity Package, Physics 124, (LAP) Studies 45, 47, and 48.

    Science.gov (United States)

    Holland, Bill

    Included are three Learning Activity Packages (LAP) studies for use in high school physics instruction: Time and Measurement Function; Force, Work, and Momentum; and Momentum, Work, and Energy. Each LAP contains a rationale for teaching the material included, student objectives (stated in behavioral terms), a list of resources (readings, problems,…

  1. Artificial Intelligence Mechanisms on Interactive Modified Simplex Method with Desirability Function for Optimising Surface Lapping Process

    Directory of Open Access Journals (Sweden)

    Pongchanun Luangpaiboon

    2014-01-01

    Full Text Available A study has been made to optimise the influential parameters of surface lapping process. Lapping time, lapping speed, downward pressure, and charging pressure were chosen from the preliminary studies as parameters to determine process performances in terms of material removal, lap width, and clamp force. The desirability functions of the-nominal-the-best were used to compromise multiple responses into the overall desirability function level or D response. The conventional modified simplex or Nelder-Mead simplex method and the interactive desirability function are performed to optimise online the parameter levels in order to maximise the D response. In order to determine the lapping process parameters effectively, this research then applies two powerful artificial intelligence optimisation mechanisms from harmony search and firefly algorithms. The recommended condition of (lapping time, lapping speed, downward pressure, and charging pressure at (33, 35, 6.0, and 5.0 has been verified by performing confirmation experiments. It showed that the D response level increased to 0.96. When compared with the current operating condition, there is a decrease of the material removal and lap width with the improved process performance indices of 2.01 and 1.14, respectively. Similarly, there is an increase of the clamp force with the improved process performance index of 1.58.

  2. Melanin targets LC3-associated phagocytosis (LAP): A novel pathogenetic mechanism in fungal disease.

    Science.gov (United States)

    Chamilos, Georgios; Akoumianaki, Tonia; Kyrmizi, Irene; Brakhage, Axel; Beauvais, Anne; Latge, Jean-Paul

    2016-05-03

    Intracellular swelling of conidia of the major human airborne fungal pathogen Aspergillus fumigatus results in surface exposure of immunostimulatory pathogen-associated molecular patterns (PAMPs) and triggers activation of a specialized autophagy pathway called LC3-associated phagocytosis (LAP) to promote fungal killing. We have recently discovered that, apart from PAMPs exposure, cell wall melanin removal during germination of A. fumigatus is a prerequisite for activation of LAP. Importantly, melanin promotes fungal pathogenicity via targeting LAP, as a melanin-deficient A. fumigatus mutant restores its virulence upon conditional inactivation of Atg5 in hematopoietic cells of mice. Mechanistically, fungal cell wall melanin selectively excludes the CYBA/p22phox subunit of NADPH oxidase from the phagosome to inhibit LAP, without interfering with signaling regulating cytokine responses. Notably, inhibition of LAP is a general property of melanin pigments, a finding with broad physiological implications.

  3. Multi-Track Friction Stir Lap Welding of 2024 Aluminum Alloy: Processing, Microstructure and Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Shengke Zou

    2016-12-01

    Full Text Available Friction stir lap welding (FSLW raises the possibility of fabricating high-performance aluminum components at low cost and high efficiency. In this study, we mainly applied FSLW to fabricate multi-track 2024 aluminum alloy without using tool tilt angle, which is important for obtaining defect-free joint but significantly increases equipment cost. Firstly, systematic single-track FSLW experiments were conducted to attain appropriate processing parameters, and we found that defect-free single-track could also be obtained by the application of two-pass processing at a rotation speed of 1000 rpm and a traverse speed of 300 mm/min. Then, multi-track FSLW experiments were conducted and full density multi-track samples were fabricated at an overlapping rate of 20%. Finally, the microstructure and mechanical properties of the full density multi-track samples were investigated. The results indicated that ultrafine equiaxed grains with the grain diameter about 9.4 μm could be obtained in FSLW samples due to the dynamic recrystallization during FSLW, which leads to a yield strength of 117.2 MPa (17.55% higher than the rolled 2024-O alloy substrate and an elongation rate of 31.05% (113.84% higher than the substrate.

  4. C/EBPβ-LAP*/LAP Expression Is Mediated by RSK/eIF4B-Dependent Signalling and Boosted by Increased Protein Stability in Models of Monocytic Differentiation.

    Directory of Open Access Journals (Sweden)

    René Huber

    Full Text Available The transcription factor C/EBPβ plays a key role in monocytic differentiation and inflammation. Its small isoform LIP is associated with proliferation at early premonocytic developmental stages and regulated via mTOR-dependent signalling. During later stages of (premonocytic differentiation there is a considerable increase in the large C/EBPβ isoforms LAP*/LAP which inhibit proliferation thus supporting terminal differentiation. Here, we showed in different models of monocytic differentiation that this dramatic increase in the LAP*/LAP protein and LAP/LIP ratio was accompanied by an only modest/retarded mRNA increase suggesting an important role for (posttranslational mechanisms. We found that LAP*/LAP formation was induced via MEK/RSK-dependent cascades, whereas mTOR/S6K1 were not involved. Remarkably, LAP*/LAP expression was dependent on phosphorylated eIF4B, an acceleratory protein of RNA helicase eIF4A. PKR inhibition reduced the expression of eIF4B and C/EBPβ in an eIF2α-independent manner. Furthermore, under our conditions a marked stabilisation of LAP*/LAP protein occurred, accompanied by reduced chymotrypsin-like proteasome/calpain activities and increased calpastatin levels. Our study elucidates new signalling pathways inducing LAP*/LAP expression and indicates new alternative PKR functions in monocytes. The switch from mTOR- to RSK-mediated signalling to orchestrate eIF4B-dependent LAP*/LAP translation, accompanied by increased protein stability but only small mRNA changes, may be a prototypical example for the regulation of protein expression during selected processes of differentiation/proliferation.

  5. C/EBPβ-LAP*/LAP Expression Is Mediated by RSK/eIF4B-Dependent Signalling and Boosted by Increased Protein Stability in Models of Monocytic Differentiation

    Science.gov (United States)

    Christmann, Martin; Friesenhagen, Judith; Westphal, Andreas; Pietsch, Daniel; Brand, Korbinian

    2015-01-01

    The transcription factor C/EBPβ plays a key role in monocytic differentiation and inflammation. Its small isoform LIP is associated with proliferation at early premonocytic developmental stages and regulated via mTOR-dependent signalling. During later stages of (pre)monocytic differentiation there is a considerable increase in the large C/EBPβ isoforms LAP*/LAP which inhibit proliferation thus supporting terminal differentiation. Here, we showed in different models of monocytic differentiation that this dramatic increase in the LAP*/LAP protein and LAP/LIP ratio was accompanied by an only modest/retarded mRNA increase suggesting an important role for (post)translational mechanisms. We found that LAP*/LAP formation was induced via MEK/RSK-dependent cascades, whereas mTOR/S6K1 were not involved. Remarkably, LAP*/LAP expression was dependent on phosphorylated eIF4B, an acceleratory protein of RNA helicase eIF4A. PKR inhibition reduced the expression of eIF4B and C/EBPβ in an eIF2α-independent manner. Furthermore, under our conditions a marked stabilisation of LAP*/LAP protein occurred, accompanied by reduced chymotrypsin-like proteasome/calpain activities and increased calpastatin levels. Our study elucidates new signalling pathways inducing LAP*/LAP expression and indicates new alternative PKR functions in monocytes. The switch from mTOR- to RSK-mediated signalling to orchestrate eIF4B-dependent LAP*/LAP translation, accompanied by increased protein stability but only small mRNA changes, may be a prototypical example for the regulation of protein expression during selected processes of differentiation/proliferation. PMID:26646662

  6. Formation of tough composite joints

    International Nuclear Information System (INIS)

    Brun, M.K.

    1997-05-01

    Joints which exhibit tough fracture behavior were formed in a composite with a Si/SiC matrix reinforced with Textron SCS-6 fibers with either boron nitride or silicon nitride fiber coatings. In composites with BN coatings fibers were aligned uniaxially, while composites with Si 3 N 4 -coated fibers had a 0/90 degree architecture. Lapped joints (joints with overlapping fingers) were necessary to obtain tough behavior. Geometrical requirements necessary to avoid brittle joint failure have been proposed. Joints with a simple overlap geometry (only a few fingers) would have to be very long in order to prevent brittle failure. Typical failure in these joints is caused by a crack propagating along the interfaces between the joint fingers. Joints of the same overall length, but with geometry changed to be symmetric about the joint centerline and with an extra shear surface exhibited tough fractures accompanied with extensive fiber pullout. The initial matrix cracking of these joints was relatively low because cracks propagated easily through the ends of the fingers. Joints with an optimized stepped sawtooth geometry produced composite-like failures with the stress/strain curves containing an elastic region followed by a region of rising stress with an increase of strain. Increasing the fiber/matrix interfacial strength from 9 to 25 MPa, by changing the fiber coating, increased matrix cracking and ultimate strength of the composite significantly. The best joints had matrix cracking stress and ultimate strength of 138 and 240 MPa, respectively. Joint failure was preceded by multiple matrix cracking in the entire composite. The high strength of the joints will permit building of structures containing joints with only a minor reduction of design stresses

  7. Reliability Analysis of Adhesive Bonded Scarf Joints

    DEFF Research Database (Denmark)

    Kimiaeifar, Amin; Toft, Henrik Stensgaard; Lund, Erik

    2012-01-01

    element analysis (FEA). For the reliability analysis a design equation is considered which is related to a deterministic code-based design equation where reliability is secured by partial safety factors together with characteristic values for the material properties and loads. The failure criteria......A probabilistic model for the reliability analysis of adhesive bonded scarfed lap joints subjected to static loading is developed. It is representative for the main laminate in a wind turbine blade subjected to flapwise bending. The structural analysis is based on a three dimensional (3D) finite...... are formulated using a von Mises, a modified von Mises and a maximum stress failure criterion. The reliability level is estimated for the scarfed lap joint and this is compared with the target reliability level implicitly used in the wind turbine standard IEC 61400-1. A convergence study is performed to validate...

  8. Laps olla muretuna veel / George Gordon Byron ; tlk. Minni Nurme

    Index Scriptorium Estoniae

    Byron, George Gordon

    2006-01-01

    Sisu: Laps olla muretuna veel ; Lachin y Gair ; Romantikale ; Värsid, kirjutatud pärnapuule Harrowþ kalmistu mäel ; Augustale : "Kui süngeks läks mu silmapiir..." ; Augustale : "Kuigi öö ju on varjand mu päeva..." ; Maryle ; Ela hästi! ; Nutvale neitsile ; Kirjutus albumisse ; Hüvastijätt ; Stantsid muusikast ; Muusikale ; Ta oma kauniduses käib ; Mu hing on morn ; Su elu lõppes ; Sa nutsid - pisarpärle täis... ; Unetuma päike ; Kuulsa Kreeka sõjalaulu järele ; Värsid ; Ludiidide laul ; Epigramme ; Pimedus ; Chilloni vang ; Prometheus ; Childe Haroldi palveränd ; Parisina ; Korsaar ; Byroni viimased read. Eluloolisi andmeid autori kohta lk. 327

  9. A study on residual stress distribution of welded joints

    International Nuclear Information System (INIS)

    Huh, Sun Chul; Lee, Kwang Young; Park, Won Jo; Yang, Hae Sug; Junge, Hae Young

    2005-01-01

    Wings for defense industry such as fighters, missiles, and rockets should have no deformation or damage on the structure, strength, and hardness safety of constituted pared and the structures near to the bodies. The structures of existing wings had holes for light weight and plates and frames were fixed with rivets or screws, thus, there were difficulties and limits in light weight. In this study, an improvement was made in current joint methods through EB welding and laser welding for light weight of wings and welding strength was measured through strength test. In addition, finite element analysis was performed for welding process so as to induce optimum welding condition

  10. Laps ja pere vajavad enam tähelepanu / Anne Tiko

    Index Scriptorium Estoniae

    Tiko, Anne, 1949-

    2001-01-01

    Lääne-Viru Maavalitsuse, Lastekaitse Liidu ja TPÜ sotsiaaltöö osakonna korraldatud kuuenda vabariikliku lastekaitsekonverentsi "Laps ja pere tänases Eestis" pöördumine haridus- ja sotsiaalministeeriumi poole

  11. PROTECTIVE TREATMENTS FOR LAPPED PORCELAIN STONEWARE TILES AND EVALUATION OF THEIR CLEANABILITY

    Directory of Open Access Journals (Sweden)

    Elisa Rambaldi

    2017-09-01

    Full Text Available Since the arrival of lapped porcelain stoneware tiles on the market, several studies have been focused on the improvement of the technical characteristics of the surfaces of these products. Surface lapping induces aesthetical improvements, but can at the same time deteriorate the performance of porcelain stoneware tiles. To overcome this problem, it is possible to protect the lapped surface with commercial waterproofing materials. In this work, lapped commercial porcelain stoneware tiles with protective stain proofing agents (FILA PD15 and FILA 1239 Plus were evaluated. The stain resistance and chemical resistance results were correlated to the morphological surface characteristics of the products with and without protection. A systematic study of the surface porosity of the tiles was carried out. Results showed that unprotected surface pores tend to fill with dirt that is hardly removable by ordinary maintenance. If the pores are protected, the dirt from foot traffic is deposited only superficially and can be removed.

  12. On the water lapping of felines and the water running of lizards: A unifying physical perspective

    OpenAIRE

    Aristoff, Jeffrey M; Stocker, Roman; Reis, Pedro M; Jung, Sunghwan

    2011-01-01

    We consider two biological phenomena taking place at the air-water interface: the water lapping of felines and the water running of lizards. Although seemingly disparate motions, we show that they are intimately linked by their underlying hydrodynamics and belong to a broader class of processes called Froude mechanisms. We describe how both felines and lizards exploit inertia to defeat gravity, and discuss water lapping and water running in the broader context of water exit and water entry, r...

  13. The Fatigue Characteristics of Bolted Lap Joints of 24S-T Alclad Sheet Materials

    Science.gov (United States)

    1946-10-01

    extremely close bolt fits are needed to o%tain maximum life of bolt ~oint~ under repeated etreseeci. -. Szvzral ty~+?+s of bolt patterns hava been tegted...Memorial Institute on spec~meris of 0.102-i.nch sheet. In particular, figure 4 shows, on a load- life diagram, . results of tests Qn single-bolt...results of tests at the Univer- sity of’ il~~nols on single—bolt specimens, Tables 10 and 11 give reeults of tests, made at the U“ uiversity of Illino~8 , on

  14. Fatigue de-bond growth in adhesively bonded single lap joints

    Indian Academy of Sciences (India)

    3Department of Aerospace Engineering, Indian Institute of Science,. Bangalore 560012 ... experimental work, specimens were fabricated and fatigue de-bond growth tests were conducted at a ... such as the stress intensity factor, are related to fatigue crack growth. ..... American Society for Testing and Materials, Philadelphia.

  15. Lap weld joint modelling and simulation of welding in programme SYSWELD

    Directory of Open Access Journals (Sweden)

    Koňár Radoslav

    2018-01-01

    Full Text Available Simulations of the welding process for applications of practice using SYSWELD are presented. This paper presents simulation of welding in the repair of high-pressure gas pipeline with steel sleeve with composite filling. Material of experimental sample was steel S355. The simulations in SYSWELD divided in to two parts: the thermal simulation followed by the mechanical simulation. The results of the numerical model, which are listed in article are compared to real experiments.

  16. Multivariate Analysis of High Through-Put Adhesively Bonded Single Lap Joints: Experimental and Workflow Protocols

    Science.gov (United States)

    2016-06-01

    GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Robert E Jensen, Daniel C DeSchepper, and David P Flanagan 5d. PROJECT NUMBER 5e. TASK...relational database center of operation ..................................................5 Fig. 5 Flowchart summary of the overall materials...Acknowledgments This research was supported in part by the US Army Education Outreach - Gains in the Education of Math and Science (GEMS) Program at

  17. Enhancing the Lithium Storage Performance of Graphene/SnO2 Nanorods by a Carbon-Riveting Strategy.

    Science.gov (United States)

    Liu, Xianghong; Ma, Tiantian; Sun, Li; Xu, Yongshan; Zhang, Jun; Pinna, Nicola

    2018-04-25

    Graphene/metal oxide (MO) nanocomposites hold great promise for application as anodes in lithium-ion batteries (LIBs). However, the restacking of graphene during subsequent processing remains a challenge to overcome for enhanced lithium storage properties. Herein, the fabrication of sandwich-architecture carbon-riveted graphene/SnO 2 nanorods, in which the SnO 2 nanorods are confined in the nanospaces formed by the carbon layers on graphene, by a two-step hydrothermal process followed by thermal treatment, is reported. Electrochemical tests show that the carbon-riveted nanolayers significantly improve the lithium storage performance of graphene/SnO 2 . The nanocomposite displays a high reversible capacity of 815 mAh g -1 after 150 cycles at 100 mA g -1 and high cycling stability at 1000 mA g -1 . This work provides an efficient way to manipulate graphene/MO-based nanocomposites for LIBs with improved performance. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Effects of process parameters on microstructure and mechanical properties of friction stir lap linear welded 6061 aluminum alloy to NZ30K magnesium alloy

    Directory of Open Access Journals (Sweden)

    Shuai Tan

    2017-03-01

    Full Text Available The microstructures and lap-shear behaviors of friction stir lap linear welded as-extruded 6061 Al alloy to as-cast Mg–3.0Nd–0.2Zn–0.7Zr (wt.% (NZ30K alloy joints were examined. Various tool rotation and travel speeds were adopted to prepare the joints. The analysis of temperature field indicates that the peak temperature for each sample can reach 450 °C, which exceeds the eutectic reaction temperatures of 437 °C and 450 °C according to the binary phase diagram of Al–Mg system. The fierce intermixing can be found at the interface between Al and Mg alloys, forming the intermetallic of Al3Mg2. Welds with the rotation speed of 900 rpm and travel speed of 120 mm/min display the highest tensile shear failure load of about 2.24 kN. The value was increased by 13% after the sample was heat treated at 400 °C for 0.5 h.

  19. Investigation on the Effect of Pulsed Energy on Strength of Fillet Lap Laser Welded AZ31B Magnesium Alloys

    Science.gov (United States)

    Salleh, M. N. M.; Ishak, M.; Aiman, M. H.; Idris, S. R. A.; Romlay, F. R. M.

    2017-09-01

    AZ31B magnesium alloy have been hugely applied in the aerospace, automotive, and electronic industries. However, welding thin sheet AZ31B was challenging due to its properties which is easily to evaporated especially using conventional fusion welding method such as metal inert gas (MIG). Laser could be applied to weld this metal since it produces lower heat input. The application of fiber laser welding has been widely since this type of laser could produce better welding product especially in the automotive sectors. Low power fiber laser was used to weld this non-ferrous metal where pulse wave (PW) mode was used. Double fillet lap joint was applied to weld as thin as 0.6 mm thick of AZ31B and the effect of pulsed energy on the strength was studied. Bond width, throat length, and penetration depth also was studied related to the pulsed energy which effecting the joint. Higher pulsed energy contributes to the higher fracture load with angle of irradiation lower than 3 °

  20. A Real-time Evaluation Technique of Fatigue Damage in Adhesively Bonded Composite-Metal Joints

    International Nuclear Information System (INIS)

    Kwon, Oh Yang; Kim, Tae Hyun

    1999-01-01

    One of the problems for practical use of fiber-reinforced plastics is the performance degradation by fatigue damage in the joints. The study is to develop a nondestructive technique for real-time evaluation of adhesively bonded composite-metal joints. From the prior study we confirmed that the bonding strength can be estimated from the correlation between the qualify of bonded parts and AUP's. We obtained a curve showing the correlation between the degree of fatigue damage and AUP's calculated from signals acquired during fatigue loading of single-lap and double-lap joints of CFRP and Al6061. The curve is an analogy to the one showing stiffness reduction (E/Eo) of polymer matrix composites by fatigue damage. From those facts, it is plausible to predict the degree of fatigue damage in real-time. Amplitude and AUP2 appeared to be optimal parameters to provide more reliable results for single-lap joints whereas Amplitude and AUP2 did for double-lap joints. It is recommended to select optimal parameters for different geometries in the application for real structures

  1. A real time evaluation technique of fatigue damage in adhesively bonded composite metal joints

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Hyun; Kwon Oh Yang [Dept. of Mechanical Engineering, Inje Univesity, Kimhae (Korea, Republic of)

    1999-05-15

    One of the problems for practical use of fiber-reinforced composite material is performance degradation by fatigue damage in the joints. The study is to develope a nondestructive technique for real-time evaluation of adhesively bonded composite-metal joints. From the prior study we confirmed that the bonding strength can be estimated from the correlation between quality of bonded parts and AUP's. We obtained a curve showing the correlation between AUP's calculated from signals obtained from single-lap and double-lap joints and the degree of fatigue damage at bonding interface during fatigue test. The curve is an analogy to the one showing stiffness reduction(E/E{sub 0}) of polymer matrix composites by fatigue damage. From those facts, it is possible to predict degree of damage in real-time. Amplitude and AUP2 appeared to be optimal parameters to provide more reliable results for single-lap joint whereas amplitude and AUP1 did for double-lap joints. It is recommended to select optimal parameters for different geometries in the real structure.

  2. A Real-time Evaluation Technique of Fatigue Damage in Adhesively Bonded Composite-Metal Joints

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Oh Yang; Kim, Tae Hyun [Inha University, Incheon (Korea, Republic of)

    1999-12-15

    One of the problems for practical use of fiber-reinforced plastics is the performance degradation by fatigue damage in the joints. The study is to develop a nondestructive technique for real-time evaluation of adhesively bonded composite-metal joints. From the prior study we confirmed that the bonding strength can be estimated from the correlation between the qualify of bonded parts and AUP's. We obtained a curve showing the correlation between the degree of fatigue damage and AUP's calculated from signals acquired during fatigue loading of single-lap and double-lap joints of CFRP and Al6061. The curve is an analogy to the one showing stiffness reduction (E/Eo) of polymer matrix composites by fatigue damage. From those facts, it is plausible to predict the degree of fatigue damage in real-time. Amplitude and AUP2 appeared to be optimal parameters to provide more reliable results for single-lap joints whereas Amplitude and AUP2 did for double-lap joints. It is recommended to select optimal parameters for different geometries in the application for real structures

  3. A real time evaluation technique of fatigue damage in adhesively bonded composite metal joints

    International Nuclear Information System (INIS)

    Kim, Tae Hyun; Kwon Oh Yang

    1999-01-01

    One of the problems for practical use of fiber-reinforced composite material is performance degradation by fatigue damage in the joints. The study is to develope a nondestructive technique for real-time evaluation of adhesively bonded composite-metal joints. From the prior study we confirmed that the bonding strength can be estimated from the correlation between quality of bonded parts and AUP's. We obtained a curve showing the correlation between AUP's calculated from signals obtained from single-lap and double-lap joints and the degree of fatigue damage at bonding interface during fatigue test. The curve is an analogy to the one showing stiffness reduction(E/E 0 ) of polymer matrix composites by fatigue damage. From those facts, it is possible to predict degree of damage in real-time. Amplitude and AUP2 appeared to be optimal parameters to provide more reliable results for single-lap joint whereas amplitude and AUP1 did for double-lap joints. It is recommended to select optimal parameters for different geometries in the real structure.

  4. Joining of polymer-metal lightweight structures using self-piercing riveting (SPR) technique: Numerical approach and simulation results

    Science.gov (United States)

    Amro, Elias; Kouadri-Henni, Afia

    2018-05-01

    Restrictions in pollutant emissions dictated at the European Commission level in the past few years have urged mass production car manufacturers to engage rapidly several strategies in order to reduce significantly the energy consumption of their vehicles. One of the most relevant taken action is light-weighting of body in white (BIW) structures, concretely visible with the increased introduction of polymer-based composite materials reinforced by carbon/glass fibers. However, the design and manufacturing of such "hybrid" structures is limiting the use of conventional assembly techniques like resistance spot welding (RSW) which are not transferable as they are for polymer-metal joining. This research aims at developing a joining technique that would eventually enable the assembly of a sheet molding compound (SMC) polyester thermoset-made component on a structure composed of several high strength steel grades. The state of the art of polymer-metal joining techniques highlighted the few ones potentially able to respond to the industrial challenge, which are: structural bonding, self-piercing riveting (SPR), direct laser joining and friction spot welding (FSpW). In this study, the promising SPR technique is investigated. Modelling of SPR process in the case of polymer-metal joining was performed through the building of a 2D axisymmetric FE model using the commercial code Abaqus CAE 6.10-1. Details of the numerical approach are presented with a particular attention to the composite sheet for which Mori-Tanaka's homogenization method is used in order to estimate overall mechanical properties. Large deformations induced by the riveting process are enabled with the use of a mixed finite element formulation ALE (arbitrary Lagrangian-Eulerian). FE model predictions are compared with experimental data followed by a discussion.

  5. Small molecules targeting LapB protein prevent Listeria attachment to catfish muscle.

    Directory of Open Access Journals (Sweden)

    Ali Akgul

    Full Text Available Listeria monocytogenes is a Gram-positive foodborne pathogen and the causative agent of listeriosis. L. monocytogenes lapB gene encodes a cell wall surface anchor protein, and mutation of this gene causes Listeria attenuation in mice. In this work, the potential role of Listeria LapB protein in catfish fillet attachment was investigated. To achieve this, boron-based small molecules designed to interfere with the active site of the L. monocytogenes LapB protein were developed, and their ability to prevent L. monocytogenes attachment to fish fillet was tested. Results indicated that seven out of nine different small molecules were effective in reducing the Listeria attachment to catfish fillets. Of these, three small molecules (SM3, SM5, and SM7 were highly effective in blocking Listeria attachment to catfish fillets. This study suggests an alternative strategy for reduction of L. monocytogenes contamination in fresh and frozen fish products.

  6. Numerical modelling in friction lap joining of aluminium alloy and carbon-fiber-reinforced-plastic sheets

    Science.gov (United States)

    Das, A.; Bang, H. S.; Bang, H. S.

    2018-05-01

    Multi-material combinations of aluminium alloy and carbon-fiber-reinforced-plastics (CFRP) have gained attention in automotive and aerospace industries to enhance fuel efficiency and strength-to-weight ratio of components. Various limitations of laser beam welding, adhesive bonding and mechanical fasteners make these processes inefficient to join metal and CFRP sheets. Friction lap joining is an alternative choice for the same. Comprehensive studies in friction lap joining of aluminium to CFRP sheets are essential and scare in the literature. The present work reports a combined theoretical and experimental study in joining of AA5052 and CFRP sheets using friction lap joining process. A three-dimensional finite element based heat transfer model is developed to compute the temperature fields and thermal cycles. The computed results are validated extensively with the corresponding experimentally measured results.

  7. Fast downscaled inverses for images compressed with M-channel lapped transforms.

    Science.gov (United States)

    de Queiroz, R L; Eschbach, R

    1997-01-01

    Compressed images may be decompressed and displayed or printed using different devices at different resolutions. Full decompression and rescaling in space domain is a very expensive method. We studied downscaled inverses where the image is decompressed partially, and a reduced inverse transform is used to recover the image. In this fashion, fewer transform coefficients are used and the synthesis process is simplified. We studied the design of fast inverses, for a given forward transform. General solutions are presented for M-channel finite impulse response (FIR) filterbanks, of which block and lapped transforms are a subset. Designs of faster inverses are presented for popular block and lapped transforms.

  8. Face validation of the Simbionix LAP Mentor virtual reality training module and its applicability in the surgical curriculum

    NARCIS (Netherlands)

    Ayodeji, I. D.; Schijven, M.; Jakimowicz, J.; Greve, J. W.

    2007-01-01

    BACKGROUND: The goal of our study was to determine expert and referent face validity of the LAP Mentor, the first procedural virtual reality (VR) laparoscopy trainer. METHODS: In The Netherlands 49 surgeons and surgical trainees were given a hands-on introduction to the Simbionix LAP Mentor training

  9. LAP TGF-Beta Subset of CD4+CD25+CD127− Treg Cells is Increased and Overexpresses LAP TGF-Beta in Lung Adenocarcinoma Patients

    Science.gov (United States)

    Islas-Vazquez, Lorenzo; Aguilar-Cazares, Dolores; Meneses-Flores, Manuel; Galicia-Velasco, Miriam; Romero-Garcia, Susana; Camacho-Mendoza, Catalina; Lopez-Gonzalez, Jose Sullivan

    2015-01-01

    Lung cancer is the leading cause of cancer death worldwide. Adenocarcinoma, the most commonly diagnosed histologic type of lung cancer, is associated with smoking. Cigarette smoke promotes inflammation on the airways, which might be mediated by Th17 cells. This inflammatory environment may contribute to tumor development. In contrast, some reports indicate that tumors may induce immunosuppressive Treg cells to dampen immune reactivity, supporting tumor growth and progression. Thus, we aimed to analyze whether chronic inflammation or immunosuppression predominates at the systemic level in lung adenocarcinoma patients, and several cytokines and Th17 and Treg cells were studied. Higher proportions of IL-17-producing CD4+ T-cells were found in smoking control subjects and in lung adenocarcinoma patients compared to nonsmoking control subjects. In addition, lung adenocarcinoma patients increased both plasma concentrations of IL-2, IL-4, IL-6, and IL-10, and proportions of Latency Associated Peptide (LAP) TGF-β subset of CD4+CD25+CD127− Treg cells, which overexpressed LAP TGF-β. This knowledge may lead to the development of immunotherapies that could inhibit the suppressor activity mediated by the LAP TGF-β subset of CD4+CD25+CD127− Treg cells to promote reactivity of immune cells against lung adenocarcinoma cells. PMID:26582240

  10. LAP TGF-Beta Subset of CD4+CD25+CD127− Treg Cells is Increased and Overexpresses LAP TGF-Beta in Lung Adenocarcinoma Patients

    Directory of Open Access Journals (Sweden)

    Lorenzo Islas-Vazquez

    2015-01-01

    Full Text Available Lung cancer is the leading cause of cancer death worldwide. Adenocarcinoma, the most commonly diagnosed histologic type of lung cancer, is associated with smoking. Cigarette smoke promotes inflammation on the airways, which might be mediated by Th17 cells. This inflammatory environment may contribute to tumor development. In contrast, some reports indicate that tumors may induce immunosuppressive Treg cells to dampen immune reactivity, supporting tumor growth and progression. Thus, we aimed to analyze whether chronic inflammation or immunosuppression predominates at the systemic level in lung adenocarcinoma patients, and several cytokines and Th17 and Treg cells were studied. Higher proportions of IL-17-producing CD4+ T-cells were found in smoking control subjects and in lung adenocarcinoma patients compared to nonsmoking control subjects. In addition, lung adenocarcinoma patients increased both plasma concentrations of IL-2, IL-4, IL-6, and IL-10, and proportions of Latency Associated Peptide (LAP TGF-β subset of CD4+CD25+CD127− Treg cells, which overexpressed LAP TGF-β. This knowledge may lead to the development of immunotherapies that could inhibit the suppressor activity mediated by the LAP TGF-β subset of CD4+CD25+CD127− Treg cells to promote reactivity of immune cells against lung adenocarcinoma cells.

  11. The effect of support springs in ends welded gap hollow YT-joint

    Directory of Open Access Journals (Sweden)

    R. F. Vieira

    Full Text Available This paper presents an analysis on the effect of support springs in an ends circular hollow sections welded into a YT joint. The overall behavior and failure of the joint were characterized under axial compression of the lap brace. Two joint failure modes were identified: chord wall plastification (Mode A and cross-sectional chord buckling (Mode F in the region below the lap brace. The system was modeled with and without support springs using the numerical finite element program Ansys. Model results were compared with experimental data in terms of principal stress in the joint intersection. The finite element model without support springs proved to be more accurate than that with support springs.

  12. iLAP: a workflow-driven software for experimental protocol development, data acquisition and analysis

    Directory of Open Access Journals (Sweden)

    McNally James

    2009-01-01

    Full Text Available Abstract Background In recent years, the genome biology community has expended considerable effort to confront the challenges of managing heterogeneous data in a structured and organized way and developed laboratory information management systems (LIMS for both raw and processed data. On the other hand, electronic notebooks were developed to record and manage scientific data, and facilitate data-sharing. Software which enables both, management of large datasets and digital recording of laboratory procedures would serve a real need in laboratories using medium and high-throughput techniques. Results We have developed iLAP (Laboratory data management, Analysis, and Protocol development, a workflow-driven information management system specifically designed to create and manage experimental protocols, and to analyze and share laboratory data. The system combines experimental protocol development, wizard-based data acquisition, and high-throughput data analysis into a single, integrated system. We demonstrate the power and the flexibility of the platform using a microscopy case study based on a combinatorial multiple fluorescence in situ hybridization (m-FISH protocol and 3D-image reconstruction. iLAP is freely available under the open source license AGPL from http://genome.tugraz.at/iLAP/. Conclusion iLAP is a flexible and versatile information management system, which has the potential to close the gap between electronic notebooks and LIMS and can therefore be of great value for a broad scientific community.

  13. Learning Activity Package, Algebra 93-94, LAPs 12-22.

    Science.gov (United States)

    Evans, Diane

    A set of 11 teacher-prepared Learning Activity Packages (LAPs) in beginning algebra, these units cover sets, properties of operations, operations over real numbers, open expressions, solution sets of equations and inequalities, equations and inequalities with two variables, solution sets of equations with two variables, exponents, factoring and…

  14. Learning Activity Package, Physical Science. LAP Numbers 8, 9, 10, and 11.

    Science.gov (United States)

    Williams, G. J.

    These four units of the Learning Activity Packages (LAPs) for individualized instruction in physical science cover nuclear reactions, alpha and beta particles, atomic radiation, medical use of nuclear energy, fission, fusion, simple machines, Newton's laws of motion, electricity, currents, electromagnetism, Oersted's experiment, sound, light,…

  15. Learning Activity Package, Physical Science. LAP Numbers 1, 2, 3, and 4.

    Science.gov (United States)

    Williams, G. J.

    These four units of the Learning Activity Packages (LAPs) for individualized instruction in physical science cover measuring techniques, operations of instruments, metric system heat, matter, energy, elements, atomic numbers, isotopes, molecules, mixtures, compounds, physical and chemical properties, liquids, solids, and gases. Each unit contains…

  16. Improving Critical Thinking Skills Using Learning Model Logan Avenue Problem Solving (LAPS)-Heuristic

    Science.gov (United States)

    Anggrianto, Desi; Churiyah, Madziatul; Arief, Mohammad

    2016-01-01

    This research was conducted in order to know the effect of Logan Avenue Problem Solving (LAPS)-Heuristic learning model towards critical thinking skills of students of class X Office Administration (APK) in SMK Negeri 1 Ngawi, East Java, Indonesia on material curve and equilibrium of demand and supply, subject Introduction to Economics and…

  17. The Fundamental Reasons Why Laptop Computers should not be Used on Your Lap

    Directory of Open Access Journals (Sweden)

    Mortazavi S. A. R.

    2016-12-01

    Full Text Available As a tendency to use new technologies, gadgets such as laptop computers are becoming more popular among students, teachers, businessmen and office workers. Today laptops are a great tool for education and learning, work and personal multimedia. Millions of men, especially those in the reproductive age, are frequently using their laptop computers on the lap (thigh. Over the past several years, our lab has focused on the health effects of exposure to different sources of electromagnetic fields such as cellular phones, mobile base stations, mobile phone jammers, laptop computers, radars, dentistry cavitrons and Magnetic Resonance Imaging (MRI. Our own studies as well as the studies performed by other researchers indicate that using laptop computers on the lap adversely affects the male reproductive health. When it is placed on the lap, not only the heat from a laptop computer can warm men’s scrotums, the electromagnetic fields generated by laptop’s internal electronic circuits as well as the Wi-Fi Radiofrequency radiation hazards (in a Wi-Fi connected laptop may decrease sperm quality. Furthermore, due to poor working posture, laptops should not be used on the lap for long hours.

  18. [Treatment of posterior cruciate ligament avulsion fracture with rivet-assisted hollow nail:a case-control study].

    Science.gov (United States)

    Zhu, Jia-Fu; Ma, Gou-Ping; Xu, Wei-Xing; Guo, Qiao-Feng; Liu, Hong

    2017-04-25

    To retrospectively investigate the clinical effect of the rivet-assisted hollow screw in the treatment of posterior cruciate ligament avulsion fracture. Total 49 patients with knee cruciate ligament avulsion fracture in the ending point of the ligament from January 2010 to December 2014 were divided into the treatment group and the control group. Thirty-one patients in treatment group were treated with rivet-assisted double cannulate nail, including 13 males and 18 females, ranging in age from 38 to 51 years old, with a mean of (40.6±5.1) years old; according to Meyers classification, 23 cases of type 2, 8 cases of type 3; 5 patients were caused by the low energy injury and 26 patients were caused by the high energy injury. Eighteen patients in control group were treated with double gold hollow screw fixation, including 5 males and 13 females, ranging in age from 36 to 52 years old, with an average age of (4.16±4.7) years old; according to Meyers classification, 14 cases of type 2 and 4 cases of type 3;2 patients were caused by the low energy injury and 16 patients were caused by the high energy injury. The operation time, postoperative complications, fracture healing time and the last AKS scoring system were compared between the two groups. All the patients were followed up, and the duration ranged from 12 to 24 months, with an average of 14.2 months. The patients in treatment group had no displacement of fracture fragments and internal fixation failure. The results of AKS score:pain was 48.1±1.5, activity was 21.3±2.7, stability was 20.9±2.5, walking ability was 47.3±1.9, under the stairs ability was 43.4±2.1, the total score was 190.7±2.9. There were 2 cases in control group had fracture fragment displacement and 1 patient had nail withdraw. The results of AKS score:pain was 40.1±2.2, activity was 20.1±0.2, stability was 18.1±3.2, walking ability was 46.3±1.7, under the stairs ability was 40.2 ±1.3, the total score was 180.2±1.4. Therefore, the

  19. Analysis and optimization of surface profile correcting mechanism of the pitch lap in large-aperture annular polishing

    Science.gov (United States)

    Zhang, Huifang; Yang, Minghong; Xu, Xueke; Wu, Lunzhe; Yang, Weiguang; Shao, Jianda

    2017-10-01

    The surface figure control of the conventional annular polishing system is realized ordinarily by the interaction between the conditioner and the lap. The surface profile of the pitch lap corrected by the marble conditioner has been measured and analyzed as a function of kinematics, loading conditions, and polishing time. The surface profile measuring equipment of the large lap based on laser alignment was developed with the accuracy of about 1μm. The conditioning mechanism of the conditioner is simply determined by the kinematics and fully fitting principle, but the unexpected surface profile deviation of the lap emerged frequently due to numerous influencing factors including the geometrical relationship, the pressure distribution at the conditioner/lap interface. Both factors are quantitatively evaluated and described, and have been combined to develop a spatial and temporal model to simulate the surface profile evolution of pitch lap. The simulations are consistent with the experiments. This study is an important step toward deterministic full-aperture annular polishing, providing a beneficial guidance for the surface profile correction of the pitch lap.

  20. Numerical and Experimental Evaluation on the Residual Stresses of Welded Joints

    Science.gov (United States)

    Huh, Sun Chul; Park, Wonjo; Yang, Haesug; Jung, Haeyoung; Kim, Chuyoung

    Wings for the defense industry such as fighters, missiles, and rockets should show no deformation or damage on the structure. The structures of existing wings had holes for weight reduction. The plates and frames were fixed with rivets or screws, which limited the weight reduction possible. In this study, an improvement was made in jointing methods through EB welding and laser welding. Welding strength was measured through tension testing. In addition, finite element analysis was performed for the welding process so as to deduce the optimum welding condition.

  1. Performance of lap splices in large-scale column specimens affected by ASR and/or DEF-extension phase.

    Science.gov (United States)

    2015-03-01

    A large experimental program, consisting of the design, construction, curing, exposure, and structural load : testing of 16 large-scale column specimens with a critical lap splice region that were influenced by varying : stages of alkali-silica react...

  2. Influence of friction stir welding parameters on titanium-aluminum heterogeneous lap joining configuration

    Science.gov (United States)

    Picot, Florent; Gueydan, Antoine; Hug, Éric

    2017-10-01

    Lap joining configuration for Friction Stir Welding process is a methodology mostly dedicated to heterogeneous bonding. This welding technology was applied to join pure titanium with pure aluminum by varying the rotation speed and the movement speed of the tool. Regardless of the process parameters, it was found that the maximum strength of the junction remains almost constant. Microstructural observations by means of Scanning Electron Microscopy and Energy Dispersive Spectrometry analysis enable to describe the interfacial join and reveal asymmetric Cold Lap Defects on the sides of the junction. Chemical analysis shows the presence of one exclusive intermetallic compound through the interface identified as TiAl3. This compound is responsible of the crack spreading of the junction during the mechanical loading. The original version of this article supplied to AIP Publishing contained an accidental inversion of the authors, names. An updated version of this article, with the authors names formatted correctly was published on 20 October 2017.

  3. Little dragons prefer flowers to maidens: a lizard that laps nectar and pollinates trees

    OpenAIRE

    Sazima, Ivan; Sazima, Cristina; Sazima, Marlies

    2005-01-01

    Lizards rarely visit and pollinate flowers, the few recent records being mostly restricted to island habitats. We report here on the Noronha skink (Euprepis atlanticus) seeking nectar in the flowers of the leguminous mulungu tree (Erythrina velutina) at Fernando de Noronha Archipelago, off northeast Brazil. The mulungu tree blooms during the dry season, and each flower secretes copious and diluted nectar throughout the day. The Noronha skink climbs up to the inflorescences and laps the nectar...

  4. Seismic fragility analysis of lap-spliced reinforced concrete columns retrofitted by SMA wire jackets

    International Nuclear Information System (INIS)

    Choi, Eunsoo; Park, Sun-Hee; Chung, Young-Soo; Kim, Hee Sun

    2013-01-01

    The aim of this study is to provide seismic fragility curves of reinforced concrete columns retrofitted by shape memory alloy wire jackets and thus assess the seismic performance of the columns against earthquakes, comparing them with reinforced concrete columns with lap-spliced and continuous reinforcement. For that purpose, this study first developed analytical models of the experimental results of the three types of columns, (1) lap-spliced reinforcement, (2) continuous reinforcement and (3) lap-spliced reinforcement and retrofitted by SMA wire jackets, using the OpenSEES program, which is oriented to nonlinear dynamic analysis. Then, a suite of ten recorded ground motions was used to conduct dynamic analyses of the analytical models with scaling of the peak ground acceleration from 0.1g to 1.0g in steps of 0.1g. From the static experimental tests, the column retrofitted with SMA wire jackets had a larger displacement ductility by a factor of 2.3 times that of the lap-spliced column, which was 6% larger compared with the ductility of the continuous reinforcement column. From the fragility analyses, the SMA wire jacketed column had median values of 0.162g and 0.567g for yield and collapse, respectively. For the yield damage state, the SMA wire jacketed column had a median value similar to the continuous reinforcement column. However, for the complete damage state, the SMA wire jacketed column showed a 1.33 times larger median value than the continuously reinforcement column. (paper)

  5. Crystallography of hornblende amphibole in LAP04840 R chondrite and implication for its metamorphic history

    International Nuclear Information System (INIS)

    Ota, Kouhei; Mikouchi, Takashi; Sugiyama, Kazumasa

    2009-01-01

    LAP04840 is an unusual R chondrite that includes abundant hornblende amphibole. LAP04840 shows a texture of equilibrated chondrite composed of 59.3% olivine, 13.5% orthopyroxene, 13.3% hornblende, 6.2% plagio-clase, 6.0% Fe-Ni sulfide, and 1.7% accessory minerals. Hornblende replaces olivine and pyroxene in both chondrules and matrices, suggesting its secondary origin. All major phases in LAP04840 are homogeneous: olivine (Fa 37 ), orthopyroxene (En 70 Wo 1 ), and plagioclase (An 8 Or 2 ). Hornblende is also nearly homogeneous, but the total sum by electron microprobe analysis is 96-98 wt%, suggesting the presence of Fe 3+ and a hydroxyl group. Synchrotron Fe-XANES analysis gives a Fe 3+ /ΣFe ratio of ∼0.6 and micro-FT-IR analysis confirms the presence of a hydroxyl group. Thus, the structural formula is (Na 0.40 K 0 . 04 ) (Ca 1.46 Mn 0.02 Fe 0.06 2+ Na 0.46 ) (Al 0.08 Fe 0.43 2+ Fe 0.75 3+ Cr 0.08 Mg 3.60 ) (Si 7.02 Al 0.98 )O 22 (OH) 2 . Single crystal X-ray diffraction of LAP04840 hornblende gives the following lattice constants: a=9.7957(9) A, b=18.0788(12) A, c=5.2949(5) A, β=104.747(3)deg. The relatively short distances of [M(1)-O=2.069 A], [M(2)-O=2.081 A], and [M(3)-O=2.058 A] suggest the feasible preference of small Fe 3+ at these sites. The mineralogy and petrology of LAP04840 are consistent with its classification as an R6 chondrite. However, the presence of hornblende and biotite is quite unique among not only R chondrites but also asteroidal meteorites in general. The presence of these hydrous minerals suggests metamorphism under high pressure and an aqueous environment probably at depth in the parent body. A thermometer using hornblende and plagioclase equilibria gives T=670-690degC. Further, a barometer using Al content in hornblende gives P=∼0.1 GPa. Although these estimates bear some uncertainties, it is likely that the size of the R chondrite parent body was large enough to induce such metamorphism. (author)

  6. The role of haptic feedback in laparoscopic training using the LapMentor II.

    Science.gov (United States)

    Salkini, Mohamad W; Doarn, Charles R; Kiehl, Nicholai; Broderick, Timothy J; Donovan, James F; Gaitonde, Krishnanath

    2010-01-01

    Laparoscopic surgery has become the standard of care for many surgical diseases. Haptic (tactile) feedback (HFB) is considered an important component of laparoscopic surgery. Virtual reality simulation (VRS) is an alternative method to teach surgical skills to surgeons in training. Newer VRS trainers such as the Simbionix Lap Mentor II provide significantly improved tactile feedback. However, VRSs are expensive and adding HFB software adds an estimated cost of $30,000 to the commercial price. The HFB provided by the Lap Mentor II has not been validated by an independent party. We used the Simbionix Lap Mentor II in this study to demonstrate the effect of adding an HFB mechanism in the VRS trainer. The study was approved by the University of Cincinnati Institutional Review Board. Twenty laparoscopically novice medical students were enrolled. Each student was asked to perform three different tasks on the Lap Mentor II and repeat each one five times. The chosen tasks demanded significant amount of traction and counter traction. The first task was to pull leaking tubes enough and clip them. The second task was stretching a jelly plate enough to see its attachments to the floor and cut these attachments. In the third task, the trainee had to separate the gallbladder from its bed on the liver. The students were randomized into two groups to perform the tasks with and without HFB. We used accuracy, speed, and economy of movement as scales to compare the performance between the two groups. The participants also completed a simple questionnaire that highlighted age, sex, and experiences in videogame usage. The two groups were comparable in age, sex, and videogame playing. No differences in the accuracy, the economy, and the speed of hand movement were noticed. In fact, adding HFB to the Lap Mentor II simulator did not contribute to any improvement in the performance of the trainees. Interestingly, we found that videogame expert players tend to have faster and more economic

  7. Joint ventures

    DEFF Research Database (Denmark)

    Sørensen, Karsten Engsig

    Afhandlingen analysere de konkurrenceretlige og selskabsretlige regler som er bestemmende for hvordan et joint venture samarbejde er struktureret......Afhandlingen analysere de konkurrenceretlige og selskabsretlige regler som er bestemmende for hvordan et joint venture samarbejde er struktureret...

  8. Coracoclavicular joint

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kun Sang; Park, Chan Il; Ahn, Jae Doo; Lim, Chong Won [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1970-10-15

    The coracoclvicular joint, a rear abnormality which may be the cause of pain in the shoulder and limitation of motion of the shoulder joint, is discussed. A case of coracoclvicular joint with shoulder pain was observed in 65 yrs old Korean male.

  9. Effect of epoxy resin and hardener containing microcapsules on healing efficiency of epoxy adhesive based metal joints

    International Nuclear Information System (INIS)

    Khan, Nazrul Islam; Halder, Sudipta; Goyat, M.S.

    2016-01-01

    Dual component microcapsules of epoxy resin and polyamine hardener with polymethyl methacrylate (PMMA) shell were synthesized using a water-oil-water emulsion solvent evaporation method. The high concentration of sodium dodecyl sulfate (SDS) was used to reduce the thickness of shell wall of dual component microcapsules. The dual microcapsules of 1:1 weight ratio were introduced in the epoxy adhesive to study the healing effect. The morphology, chemical structure and thermal characteristics of the microcapsules were characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA), respectively. The insertion of dual component microcapsules in epoxy matrix reduced the lap shear strength of adhesive joints, which may be attributed to the generation of stress concentration cites because of micron sized capsules. However, the extension and absorbed failure energy of adhesive joints under uniaxial loading increased with the increase of concentration of dual microcapsules. The viscoelastic nature of the dual microcapsules may be responsible for this enhancement. Significant enhancement in the healing efficiency (90.93%) of the joints was achieved for 10 wt% of dual microcapsules. The crack pinning and crack blunting mechanisms at the vicinity of the crack path adjacent to the microcapsules were found responsible for significant enhancement in the healing efficiency of the adhesive joints. - Highlights: • High SDS concentration was used to control the dual component microcapsules shell wall thickness. • Self-healing performance of dual component microcapsules reinforced epoxy adhesive based single lap joints was studied. • 90.93% of the damage healing was achieved for self-healing adhesive based single lap joints. • Increase in concentration of microcapsules reduces the lap shear properties of the self-healing joints.

  10. Effect of epoxy resin and hardener containing microcapsules on healing efficiency of epoxy adhesive based metal joints

    Energy Technology Data Exchange (ETDEWEB)

    Khan, Nazrul Islam [Department of Mechanical Engineering, National Institute of Technology Silchar, Silchar 788010, Assam (India); Halder, Sudipta, E-mail: shalder@nits.ac.in [Department of Mechanical Engineering, National Institute of Technology Silchar, Silchar 788010, Assam (India); Goyat, M.S. [Department of Physics, University of Petroleum & Energy Studies, Dehradun, Uttarakhand 248007 (India)

    2016-03-01

    Dual component microcapsules of epoxy resin and polyamine hardener with polymethyl methacrylate (PMMA) shell were synthesized using a water-oil-water emulsion solvent evaporation method. The high concentration of sodium dodecyl sulfate (SDS) was used to reduce the thickness of shell wall of dual component microcapsules. The dual microcapsules of 1:1 weight ratio were introduced in the epoxy adhesive to study the healing effect. The morphology, chemical structure and thermal characteristics of the microcapsules were characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA), respectively. The insertion of dual component microcapsules in epoxy matrix reduced the lap shear strength of adhesive joints, which may be attributed to the generation of stress concentration cites because of micron sized capsules. However, the extension and absorbed failure energy of adhesive joints under uniaxial loading increased with the increase of concentration of dual microcapsules. The viscoelastic nature of the dual microcapsules may be responsible for this enhancement. Significant enhancement in the healing efficiency (90.93%) of the joints was achieved for 10 wt% of dual microcapsules. The crack pinning and crack blunting mechanisms at the vicinity of the crack path adjacent to the microcapsules were found responsible for significant enhancement in the healing efficiency of the adhesive joints. - Highlights: • High SDS concentration was used to control the dual component microcapsules shell wall thickness. • Self-healing performance of dual component microcapsules reinforced epoxy adhesive based single lap joints was studied. • 90.93% of the damage healing was achieved for self-healing adhesive based single lap joints. • Increase in concentration of microcapsules reduces the lap shear properties of the self-healing joints.

  11. APPLICATION PROSPECTS OF THREADED JOINT OF ARMATURE

    Directory of Open Access Journals (Sweden)

    A. V. Radkevych

    2014-06-01

    Full Text Available Purpose. One of the main technological operations of buildings construction on the basis of monolithic frame systems is the production of mesh reinforcement. The current interest is the new ways specification of advanced bonding armature techniques without reliability weakness and design of the building in whole, as well as the finding of use prospects of screw-threaded joint of armature as the most technological and economic method of re-bars joints. Methodology. Advantages and disadvantages analysis of existing rebar compound technologies was implemented by couplings of different types and constructions. The most promising vertical constructions for the vertical bars joints in frameworks were determined. Findings. Researches of existing technologies of rebar joints by the couplings of different construction were carried out. The installation method of mesh reinforcement of vertical structural elements with the use of the special catching devices was developed. It allows considerably accelerating installation of mesh reinforcement. Originality. Regularity of labor intensiveness change of mesh reinforcement installation of columns at armature joint in vertical position by threaded couplings with the help of catching devices using special construction was determined. This allows substantially reducing the labor expenditures during installation of these elements. Dependency of labor intensiveness and cost of lap welding armature joints, by tub-seam welding and by thread coupling depending on its diameter was designated. Regularity of labor intensiveness changes of installation at armature joints by different methods taking into account preparatory works was defined. Practical value. The analysis of mechanical armature joints techniques was conducted. It will allow selecting methods of armature joints to increase the speed of construction works more economical and effective.

  12. One hundred cases of laparoscopic subtotal hysterectomy using the PK and Lap Loop systems.

    Science.gov (United States)

    Erian, John; El-Toukhy, Tarek; Chandakas, Stefanos; Theodoridis, Theo; Hill, Nicholas

    2005-01-01

    To evaluate the safety and short-term outcomes of laparoscopic subtotal hysterectomy using the PK and Lap Loop systems. Prospective observational study (Canadian Task Force classification II-2). Princess Royal University and Chelsfield Park Hospitals, Kent, UK. One hundred women who underwent laparoscopic subtotal hysterectomy for menorrhagia from February 2003 through July 2004. The procedure was performed using the Plasma Kinetic (PK) system to seal the vascular pedicles and the Lap Loop system to separate the uterus at the level of the internal os. The uterus was removed from the abdominal cavity mainly by morcellation or posterior colpotomy. Of 100 patients, 59 were operated on as outpatients. Mean patient age was 44.6 years, median parity was 2, mean body mass index was 26.8, and mean duration of symptoms was 4 years. Clinically, the uterus was enlarged in 70 patients, and preoperative ultrasound scanning suggested the presence of uterine myomas in 42 patients. In addition to hysterectomy, 47 patients had concomitant pelvic surgery. The mean total operating time was 45.5 minutes, and mean estimated blood loss was 114 mL. The overall major complication rate was 2%; two patients required blood transfusion after surgery. There were no bowel or urinary tract injuries, unintended laparotomy, return to operating room, or anesthetic complications. At follow-up, all patients were satisfied with surgery. Laparoscopic subtotal hysterectomy using the PK and Lap Loop systems for treatment of therapy-resistant menorrhagia is safe, can be performed as an outpatient procedure, and is associated with reduced operating time and high patient satisfaction.

  13. Construct validity of the LapVR virtual-reality surgical simulator.

    Science.gov (United States)

    Iwata, Naoki; Fujiwara, Michitaka; Kodera, Yasuhiro; Tanaka, Chie; Ohashi, Norifumi; Nakayama, Goro; Koike, Masahiko; Nakao, Akimasa

    2011-02-01

    Laparoscopic surgery requires fundamental skills peculiar to endoscopic procedures such as eye-hand coordination. Acquisition of such skills prior to performing actual surgery is highly desirable for favorable outcome. Virtual-reality simulators have been developed for both surgical training and assessment of performance. The aim of the current study is to show construct validity of a novel simulator, LapVR (Immersion Medical, San Jose, CA, USA), for Japanese surgeons and surgical residents. Forty-four subjects were divided into the following three groups according to their experience in laparoscopic surgery: 14 residents (RE) with no experience in laparoscopic surgery, 14 junior surgeons (JR) with little experience, and 16 experienced surgeons (EX). All subjects executed "essential task 1" programmed in the LapVR, which consists of six tasks, resulting in automatic measurement of 100 parameters indicating various aspects of laparoscopic skills. Time required for each task tended to be inversely correlated with experience in laparoscopic surgery. For the peg transfer skill, statistically significant differences were observed between EX and RE in three parameters, including total time and average time taken to complete the procedure and path length for the nondominant hand. For the cutting skill, similar differences were observed between EX and RE in total time, number of unsuccessful cutting attempts, and path length for the nondominant hand. According to the programmed comprehensive evaluation, performance in terms of successful completion of the task and actual experience of the participants in laparoscopic surgery correlated significantly for the peg transfer (P=0.007) and cutting skills (P=0.026). The peg transfer and cutting skills could best distinguish between EX and RE. This study is the first to provide evidence that LapVR has construct validity to discriminate between novice and experienced laparoscopic surgeons.

  14. Using quantum dots to tag subsurface damage in lapped and polished glass samples

    International Nuclear Information System (INIS)

    Williams, Wesley B.; Mullany, Brigid A.; Parker, Wesley C.; Moyer, Patrick J.; Randles, Mark H.

    2009-01-01

    Grinding, lapping, and polishing are finishing processes used to achieve critical surface parameters in a variety of precision optical and electronic components. As these processes remove material from the surface through mechanical and chemical interactions, they may induce a damaged layer of cracks, voids, and stressed material below the surface. This subsurface damage (SSD) can degrade the performance of a final product by creating optical aberrations due to diffraction, premature failure in oscillating components, and a reduction in the laser induced damage threshold of high energy optics. As these defects lie beneath the surface, they are difficult to detect, and while many methods are available to detect SSD, they can have notable limitations regarding sample size and type, preparation time, or can be destructive in nature. The authors tested a nondestructive method for assessing SSD that consisted of tagging the abrasive slurries used in lapping and polishing with quantum dots (nano-sized fluorescent particles). Subsequent detection of fluorescence on the processed surface is hypothesized to indicate SSD. Quantum dots that were introduced to glass surfaces during the lapping process were retained through subsequent polishing and cleaning processes. The quantum dots were successfully imaged by both wide field and confocal fluorescence microscopy techniques. The detected fluorescence highlighted features that were not observable with optical or interferometric microscopy. Atomic force microscopy and additional confocal microscope analysis indicate that the dots are firmly embedded in the surface but do not appear to travel deep into fractures beneath the surface. Etching of the samples exhibiting fluorescence confirmed that SSD existed. SSD-free samples exposed to quantum dots did not retain the dots in their surfaces, even when polished in the presence of quantum dots.

  15. Handheld multi-channel LAPS device as a transducer platform for possible biological and chemical multi-sensor applications

    International Nuclear Information System (INIS)

    Wagner, Torsten; Molina, Roberto; Yoshinobu, Tatsuo; Kloock, Joachim P.; Biselli, Manfred; Canzoneri, Michelangelo; Schnitzler, Thomas; Schoening, Michael J.

    2007-01-01

    The light-addressable potentiometric sensor is a promising technology platform for multi-sensor applications and lab-on-chip devices. However, many prior LAPS developments suffer from their lack in terms of non-portability, insufficient robustness, complicate handling, etc. Hence, portable and robust LAPS-based measurement devices have been investigated by the authors recently. In this work, a 'chip card'-based light-addressable potentiometric sensor system is presented. The utilisation of ordinary 'chip cards' allows an easy handling of different sensor chips for a wide range of possible applications. The integration of the electronic and the mechanical set-up into a single reader unit results in a compact design with the benefits of portability and low required space. In addition, the presented work includes a new multi-frequency measurement procedure, based on an FFT algorithm, which enables the simultaneous real-time measurement of up to 16 sensor spots. The comparison between the former batch-LAPS and the new FFT-based LAPS set-up will be presented. The immobilisation of biological cells (CHO: Chinese hamster ovary) demonstrates the possibility to record their metabolic activity with 16 measurement spots on the same chip. Furthermore, a Cd 2+ -selective chalcogenide-glass layer together with a pH-sensitive Ta 2 O 5 layer validates the use of the LAPS for chemical multi-sensor applications

  16. Assessment of vitamin D status and serum CrossLaps levels in adults with primary lactose malabsorption.

    Science.gov (United States)

    Enko, D; Kriegshäuser, G; Stolba, R; Mangge, H; Brandstetter, D; Mayr, N; Forstner, T; Halwachs-Baumann, G

    2016-09-01

    Primary adult-type lactose malabsorption (PALM) is a widespread inherited autosomal recessive condition, which is considered to be associated with osteoporosis. This prospective study aimed at assessing the 25-hydroxy-vitamin D (25(OH)D) status and serum CrossLaps levels in individuals with PALM and normal controls. All participants (n=210) underwent genotyping for the LCT C/T-13910 polymorphism, 25(OH)D and CrossLaps measurements and clinical examinations. In addition, the anthropometric data (that is, height, weight and body mass index) were determined. Fifty-five individuals with PALM (that is, LCT C/C-13910 homozygotes) showed lower 25(OH)D (mean: 24.95±10.04 vs 28.59±9.56 ng/ml, P=0.018) and higher CrossLaps serum levels (mean: 0.46±0.31 vs 0.43±0.49 ng/ml, P=0.251) compared with 155 normal controls (that is, LCT C/T-13910 hetero- or T/T-13910 homozygotes). Anthropometric data were similar between PALM probands and controls. Individuals with PALM were found to have lower 25(OH)D and higher CrossLaps serum levels compared with normal controls. In order to preserve life-long bone health, routine 25(OH)D and CrossLaps serum measurements should be performed in individuals with PALM.

  17. Mechanisms of the porosity formation during the fiber laser lap welding of aluminium alloy

    Directory of Open Access Journals (Sweden)

    J. Wang

    2015-10-01

    Full Text Available When joining the aluminum alloys, one of the biggest challenges is the formation of porosity, which deteriorates mechanical properties of welds. In this study, the lap welding was conducted on an aluminum alloy 5754 metal sheets with a thickness of 2 mm. The effects of various laser welding parameters on the weld quality were investigated. The porosity content was measured by X-ray inspections. The key is to control the solidification duration of molten pool. When the solidification duration of molten pool is large enough, more bubbles can escape from the molten pool and less remain as porosity.

  18. Determination of L-AP4-bound human mGlu8 receptor amino terminal domain structure and the molecular basis for L-AP4’s group III mGlu receptor functional potency and selectivity

    Energy Technology Data Exchange (ETDEWEB)

    Schkeryantz, Jeffery M.; Chen, Qi; Ho, Joseph D.; Atwell, Shane; Zhang, Aiping; Vargas, Michelle C.; Wang, Jing; Monn, James A.; Hao, Junliang (Lilly)

    2018-02-01

    Here, L-2-Amino-4-phosphonobutyric acid (L-AP4) is a known potent and selective agonist for the Group III mGlu receptors. However, it does not show any selectivity among the individual group III mGlu subtypes. In order to understand the molecular basis for this group selectivity, we solved the first human mGlu8 amino terminal domain (ATD) crystal structures in complex with L-glu and L-AP4. In comparison with other published L-glu-bound mGlu ATD structures, we have observed L-glu binds in a significantly different manner in mGlu1. Furthermore, these new structures provided evidence that both the electronic and steric nature of the distal phosphate of L-AP4 contribute to its exquisite Group III functional agonist potency and selectivity.

  19. A review on model updating of joint structure for dynamic analysis purpose

    Directory of Open Access Journals (Sweden)

    Zahari S.N.

    2016-01-01

    Full Text Available Structural joints provide connection between structural element (beam, plate etc. in order to construct a whole assembled structure. There are many types of structural joints such as bolted joint, riveted joints and welded joints. The joints structures significantly contribute to structural stiffness and dynamic behaviour of structures hence the main objectives of this paper are to review on method of model updating on joints structure and to discuss the guidelines to perform model updating for dynamic analysis purpose. This review paper firstly will outline some of the existing finite element modelling works of joints structure. Experimental modal analysis is the next step to obtain modal parameters (natural frequency & mode shape to validate and improve the discrepancy between results obtained from experimental and the simulation counterparts. Hence model updating will be carried out to minimize the differences between the two results. There are two methods of model updating; direct method and iterative method. Sensitivity analysis employed using SOL200 in NASTRAN by selecting the suitable updating parameters to avoid ill-conditioning problem. It is best to consider both geometrical and material properties in the updating procedure rather than choosing only a number of geometrical properties alone. Iterative method was chosen as the best model updating procedure because the physical meaning of updated parameters are guaranteed although this method required computational effort compare to direct method.

  20. Bonded Joints with “Nano-Stitches”: Effect of Carbon Nanotubes on Load Capacity and Failure Modes

    Directory of Open Access Journals (Sweden)

    Henrique N. P. Oliva

    Full Text Available Abstract Carbon nanotubes were employed as adhesive reinforcement/nano-stitches to aluminum bonded joints. The CNT addition to an epoxy adhesive not only lead to an increase on load capacity but it is also the most probable cause of the mixed failure mode (adhesive/cohesive. The damage evolution was described as the stiffness decrease and the failure mixed modes were related to the load capacity. Although the presence of CNT cluster were observed, in small concentrations (< 1.0 wt. %, these clusters acted as crack stoppers and lead to an increase on lap joint shear strength. The addition of 2.0 wt. % carbon nanotubes lead to an increase on load capacity of approximately 116.2 % when the results were compared against the single lap joints without carbon nanotubes.

  1. Lap time simulation and design optimisation of a brushed DC electric motorcycle for the Isle of Man TT Zero Challenge

    Science.gov (United States)

    Dal Bianco, N.; Lot, R.; Matthys, K.

    2018-01-01

    This works regards the design of an electric motorcycle for the annual Isle of Man TT Zero Challenge. Optimal control theory was used to perform lap time simulation and design optimisation. A bespoked model was developed, featuring 3D road topology, vehicle dynamics and electric power train, composed of a lithium battery pack, brushed DC motors and motor controller. The model runs simulations over the entire ? or ? of the Snaefell Mountain Course. The work is validated using experimental data from the BX chassis of the Brunel Racing team, which ran during the 2009 to 2015 TT Zero races. Optimal control is used to improve drive train and power train configurations. Findings demonstrate computational efficiency, good lap time prediction and design optimisation potential, achieving a 2 minutes reduction of the reference lap time through changes in final drive gear ratio, battery pack size and motor configuration.

  2. L-Cysteine and L-AP4 microinjections in the rat caudal ventrolateral medulla decrease arterial blood pressure.

    Science.gov (United States)

    Takemoto, Yumi

    2014-12-01

    The thiol amino acid L-cysteine increases arterial blood pressure (ABP) when injected into the cerebrospinal fluid space in conscious rats, indicating a pressor response to centrally acting L-cysteine. A prior synaptic membrane binding assay suggests that L-cysteine has a strong affinity for the L-2-amino-4-phosphonobutyric acid (L-AP4) binding site. The central action of L-cysteine may be vial-AP4 sensitive receptors. The present study investigated cardiovascular responses to L-cysteine and L-ap4 microinjected into the autonomic area of the caudal ventrolateral medulla (CVLM) where inhibitory neurons regulate ABP via pre-sympathetic vasomotor neurons. Both the injection of L-cysteine and L-AP4 in the CVLM sites identified with L-glutamate produced the same depressor and bradycardic responses in urethane-anesthetized rats. Neither a prior antagonist microinjection of MK801 for the N-methyl-D-aspartate (NMDA) receptor nor CNQX for the non-NMDA receptor attenuated the responses to L-cysteine, but the combination of the two receptor blocking with an additional prior injection abolished the response. In contrast, either receptor blockade alone abolished the response to L-AP4, indicating distinct mechanisms between responses to L-cysteine and L-AP4 in the CVLM. The results indicate that the CVLM is a central active site for L-cysteine's cardiovascular response. Central L-cysteine's action could be independent of the L-AP4 sensitive receptors. Cardiovascular regulation may involve endogenous L-cysteine in the CVLM. Further multidisciplinary examinations are required to elaborate on L-cysteine's functional roles in the CVLM. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Impaired circulating CD4+ LAP+ regulatory T cells in patients with acute coronary syndrome and its mechanistic study.

    Directory of Open Access Journals (Sweden)

    Zheng-Feng Zhu

    Full Text Available OBJECTIVE: CD4(+ latency-associated peptide (LAP(+ regulatory T cells (Tregs are a newly discovered T cell subset in humans and the role of these cells in patients with acute coronary syndrome (ACS has not been explored. We designed to investigate whether circulating frequency and function of CD4(+LAP(+ Tregs are defective in ACS. METHODS: One hundred eleven ACS patients (acute myocardial infarction and unstable angina and 117 control patients were enrolled in the study. The control patients consisted of chronic stable angina (CSA and chest pain syndrome (CPS. The frequencies of circulating CD4(+LAP(+ Tregs and the expression of the transmembrane protein glycoprotein-A repetitions predominant (GARP on CD4(+ T cells were determined by flow cytometry. The function of CD4(+LAP(+ Tregs was detected using thymidine uptake. Serum interleukin-10 (IL-10 and transforming growth factor-β protein (TGF-β levels were detected using ELISA and expression of GARP mRNA in peripheral blood mononuclear cells (PBMCs was measured by real time-polymerase chain reaction. RESULTS: We found ACS patients had a significantly lower frequency of circulating CD4(+LAP(+ Tregs, and the function of these cells was reduced compared to controls. The expression of GARP in CD4(+ T cells and the serum levels of TGF-β in ACS patients were lower than those of control patients. The serum levels of IL-10 were similar between the two cohorts. CONCLUSIONS: A novel regulatory T cell subset, defined as CD4(+LAP(+ T cells is defective in ACS patients.

  4. Lap Shear and Impact Testing of Ochre and Beeswax in Experimental Middle Stone Age Compound Adhesives.

    Science.gov (United States)

    Kozowyk, P R B; Langejans, G H J; Poulis, J A

    2016-01-01

    The production of compound adhesives using disparate ingredients is seen as some of the best evidence of advanced cognition outside of the use of symbolism. Previous field and laboratory testing of adhesives has shown the complexities involved in creating an effective Middle Stone Age glue using Acacia gum. However, it is currently unclear how efficient different adhesive recipes are, how much specific ingredients influence their performance, and how difficult it may have been for those ingredients to be combined to maximum effect. We conducted a series of laboratory-based lap shear and impact tests, following modern adhesion testing standards, to determine the efficacy of compound adhesives, with particular regard to the ingredient ratios. We tested rosin (colophony) and gum adhesives, containing additives of beeswax and ochre in varying ratios. During both lap shear and impact tests compound rosin adhesives performed better than single component rosin adhesives, and pure acacia gum was the strongest. The large difference in performance between each base adhesive and the significant changes in performance that occur due to relatively small changes in ingredient ratios lend further support to the notion that high levels of skill and knowledge were required to consistently produce the most effective adhesives.

  5. PLASMA POLYMER FILMS AS ADHESION PROMOTING PRIMERS FOR ALUMINUM. PART II: STRENGTH AND DURABILITY OF LAP JOINTS

    Science.gov (United States)

    Plasma polymerized hexamethyldisiloxane (HMDSO) films (~800 A in thickness) were deposited onto 6111-T4 aluminum substrates in radio frequency and microwave powered reactors and used as primers for structural adhesive bonding. Processing variables such as substrate pre-treatment,...

  6. PENINGKATAN KEMAMPUAN PEMECAHAN MASALAH MATEMATIKA SISWA MELALUI MODEL PEMBELAJARAN LAPS-HEURISTIC DIKELAS X SMAN 2 BATANG ANAI

    Directory of Open Access Journals (Sweden)

    Adri Nofrianto

    2017-01-01

    Full Text Available Penelitian ini bertujuan untuk mengetahui peningkatan kemampuan pemecahan masalah matematika siswa melalui model pembelajaran LAPS-Heuristic. Jenis penelitian ini yaitu penelitian deskriptif kualitatif. Subjek dalam penelitian ini dipilih dua siswa dari kelas penelitian yaitu kelas X SMAN 2 Batang Anai. Subjek yang dipilih dalam merupakan siswa yang memiliki kemampuan matematika tinggi. Data dikumpulkan melalui tes pemecahan masalah dan wawancara. Hal ini dilakukan sebelum dan sesudah penerapa model pembelajaran LAPS-Heuristic. Berdasarkan hasil deskripsi dan analisis data, dapat dilihat perkembangan kemampuan pemecahan masalah matematika siswa meningkat pada saat dilakukan tes akhir. Pada hasil penilaian berdasarkan rubrik pemecahan masalah matematika, diperoleh tingkat kategori sangat memuaskan dengan indikator pencapaian: memahami soal dengan benar, rencana strategi penyelesaian yang benar, mengarah pada jawaban yang benar dan adanya pengecekan kembali hasil perhitungan, sehingga dapat disimpulkan bahwa model pembelajaran LAPS-Heuristic berpengaruh terhadap kemampuan pemecahan masalah matematika siswa kelas X SMAN 2 Batag Anai. Kata kunci: kesulitan matematika, pemecahan masalah, LAPS-Heuristic This research aims to determine the increase in mathematics problem solving ability of students through learning model LAPS-Heuristic. Type of research is a qualitative descriptive study. The subjects in this study were selected two students from class research that is class X SMAN 2 Batang Anai. Subjects selected were the students who have high math skills. Data were collected through a problem-solving test and interview. This data collection was done before and after the implementation of learning model LAPS-Heuristic. Based on the description and analysis of the test, it can be seen that the development of mathematical problem solving ability of students increased at the time of the final test. The results of the assessment under the rubric of

  7. The LapG protein plays a role in Pseudomonas aeruginosa biofilm formation by controlling the presence of the CdrA adhesin on the cell surface

    DEFF Research Database (Denmark)

    Rybtke, Morten; Berthelsen, Jens; Yang, Liang

    2015-01-01

    Pseudomonas aeruginosa is a clinically relevant species involved in biofilm-based chronic infections. We provide evidence that the P. aeruginosa LapG protein functions as a periplasmic protease that can cleave the protein adhesin CdrA off the cell surface, and thereby plays a role in biofilm...... formation and biofilm dispersal. The P. aeruginosa LapG protein is shown to be a functional homolog of the Pseudomonas putida LapG protein which has previously been shown to function as a periplasmic protease that targets the surface adhesin LapA. Transposon mutagenesis and characterization of defined...... and whole-cell protein fractions showed that CdrA was retained in the whole-cell protein fraction when LapG was absent, whereas it was found in the culture supernatant when LapG was present. The finding that CdrA is a target of LapG in P. aeruginosa is surprising because CdrA has no homology to LapA....

  8. Bench for mechanical cleaning of circular welded joints

    International Nuclear Information System (INIS)

    Sklifasovskij, V.M.

    1986-01-01

    A special bench for weld reinforcement removal and mechanical cleaning of the heat affected zones was designed to provide for a possibility of an ultrasonic testing of welded joints in the course of steam generator section fabrication. The bench comprises a mechanized roller support for fixing and rotating the workpiece; a lap-cutting device for external machining; milling/grinding tractor for internal machining and a delivery table for tractor approach and departure. The bench performance and overall view are presented. The operation succession is described

  9. Structural Performance of Inconel 625 Superalloy Brazed Joints

    Science.gov (United States)

    Chen, Jianqiang; Demers, Vincent; Cadotte, Eve-Line; Turner, Daniel; Bocher, Philippe

    2017-02-01

    The purpose of this work was to investigate tensile and fatigue behaviors of Inconel 625 superalloy brazed joints after transient liquid-phase bonding process. Brazing was performed in a vacuum furnace using a nickel-based filler metal in a form of paste to join wrought Inconel 625 plates. Mechanical tests were carried out on single-lap joints under various lap distance-to-thickness ratios. The fatigue crack initiation and crack growth modes were examined via metallographic analysis, and the effect of local stress on fatigue life was assessed by finite element simulations. The fatigue results show that fatigue strength and endurance limit increase with overlap distance, leading to a relatively large scatter of results. Fatigue cracks nucleated in the high-stressed region of the weld fillets from brittle eutectic phases or from internal brazing cavities. The present work proposes to rationalize the results by using the local stress at the brazing fillet. When using this local stress, all fatigue-obtained results find themselves on a single S- N curve, providing a design curve for any joint configuration in fatigue solicitation.

  10. Temporomandibular joint

    International Nuclear Information System (INIS)

    Westesson, P.L.; Hatala, M.; Tallents, R.H.; Katzberg, R.W.; Musgrave, M.; Levitt, S.

    1990-01-01

    This paper determines the frequency of MR signs of abnormal temporomandibular joints (TMJs) in asymptomatic volunteers. Forty-two volunteers with 84 clinically normal TMJs were imaged in the sagittal and coronal planes with surface coil MR imaging. Sagittal closed and open and coronal closed views were obtained bilaterally in all volunteers. The images were classified as normal (superior disk position) or abnormal (disk displacement of degenerative joint disease). Eighteen joints in 11 volunteers were abnormal; 12 had disk displacement with reduction and six had disk displacement without reduction, with associated degenerative joint disease in three of the six. Asymptomatic internal derangement and degenerative joint disease occur in about one-fourth of asymptomatic volunteers

  11. Micro friction stir lap welding of AISI 430 ferritic stainless steel: a study on the mechanical properties, microstructure, texture and magnetic properties

    Science.gov (United States)

    Mostaan, Hossein; Safari, Mehdi; Bakhtiari, Arash

    2018-04-01

    In this study, the effect of friction stir welding of AISI 430 (X6Cr17, material number 1.4016) ferritic stainless steel is examined. Two thin sheets with dimensions of 0.4 × 50 × 200 mm3 are joined in lap configuration. Optical microscopy and field emission electron microscopy were used in order to microstructural evaluations and fracture analysis, respectively. Tensile test and microhardness measurements are employed in order to study the mechanical behaviors of welds. Also, vibrational sample magnetometry (VSM) is employed for characterizing magnetic properties of welded samples. Texture analysis is carried out in order to clarify the change mechanism of magnetic properties in the welded area. The results show that AISI 430 sheets are successfully joined considering both, the appearance of the welding bead and the strength of the welded joint. It is found that by friction stir welding of AISI 430 sheets, texture components with easy axes magnetization have been replaced by texture components with harder magnetization axes. VSM analysis showed that friction stir welding leads to increase in residual induction (Br) and coercivity (Hc). This increase is attributed to the grain refining due the friction stir welding and formation of texture components with harder axes of magnetizations.

  12. PENGEMBANGAN KARAKTER KEDISIPLINAN DAN KEMAMPUAN PEMECAHAN MASALAH MELALUI MODEL LAPS-HEURISTIK MATERI LINGKARAN KELAS-VIII

    Directory of Open Access Journals (Sweden)

    Sri Wahyuni

    2015-08-01

    Full Text Available Tujuan penelitian ini adalah untuk mengetahui (1 apakah pembelajaran dengan model pembelajaran LAPS-Heuristik pada materi lingkaran kelas-VIII dapat mengembangkan karakter kedisiplinan peserta didik, (2 apakah pembelajaran dengan model pembelajaran LAPS-Heuristik pada materi lingkaran kelas-VIII dapat meningkatkan kemampuan pemecahan masalah peserta didik, (3 apakah kemampuan pemecahan masalah matematika peserta didik yang diajar dengan model pembelajaran LAPS-Heuristik pada materi lingkaran kelas-VIII dapat mencapai kriteria ketuntasan minimal yang ditentukan. Desain penelitian ini adalah kualitatif deskriptif, artinya menggambarkan atau mendeskripsikan kejadian-kejadian yang menjadi pusat perhatian secara kualitatif dan berdasar data kualitatif. Penentuan sumber data dalam penelitian ini menggunakan teknik purposive sampling, yaitu dipilih dengan pertimbangan dan tujuan tertentu. Data diperoleh dengan observasi, wawancara, dan tes yang kemudian dianalisis menggunakan analisis kualitatif dan analisis gain untuk mengukur peningkatan. Analisis kualitatif menunjukkan karakter kedisiplinan dan kemampuan pemecahan masalah peserta didik meningkat, serta kemampuan pemecahan masalah peserta didik mencapai KKM melalui model pembelajaran LAPS-Heuristik.

  13. Research on the design of surface acquisition system of active lap based on FPGA and FX2LP

    Science.gov (United States)

    Zhao, Hongshen; Li, Xiaojin; Fan, Bin; Zeng, Zhige

    2014-08-01

    In order to research the dynamic surface shape changes of active lap during the processing, this paper introduces a dynamic surface shape acquisition system of active lap using FPGA and USB communication. This system consists of high-precision micro-displacement sensor array, acquisition board, PC computer composition, and acquisition circuit board includes six sub-boards based on FPGA, a hub-board based on FPGA and USB communication. A sub-board is responsible for a number of independent channel sensors' data acquisition; hub-board is responsible for creating encoder simulation tools to active lap deformation control system with location information, sending synchronization information to latch the sensor data in all of the sub-boards for a time, while addressing the sub-boards to gather the sensor data in each sub-board one by one and transmitting all the sensor data together with location information via the USB chip FX2LP to the host computer. Experimental results show that the system is capable of fixing the location and speed of active lap, meanwhile the control of surface transforming and dynamic surface data acquisition at a certain location in the processing is implemented.

  14. Swimming in a contained space: Understanding the experience of indoor lap swimmers.

    Science.gov (United States)

    Ward, Miranda

    2017-07-01

    Drawing on ethnographic work, this paper explores the convergence of bodies, materialities and practices found at the indoor swimming pool - a space that has not often been the subject of geographical study, in spite of the fact that swimming is one of the most popular forms of exercise in countries such as the UK. The paper focuses on the "contained" nature of the indoor pool environment, examining the distinct experience this can create for lap swimmers. This focus is placed in the context of a broader politics of exercise, with an emphasis on the popularity and potential benefits of swimming, as well as less encouraging facts about participation and facility provision, suggesting that in order to encourage further uptake of swimming and preservation of swimming facilities the voices and experiences of regular swimmers should be considered. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. FRACTURE MECHANICS APPROACH TO ESTIMATE FATIGUE LIVES OF WELDED LAP-SHEAR SPECIMENS

    Energy Technology Data Exchange (ETDEWEB)

    Lam, P.; Michigan, J.

    2014-04-25

    A full range of stress intensity factor solutions for a kinked crack is developed as a function of weld width and the sheet thickness. When used with the associated main crack solutions (global stress intensity factors) in terms of the applied load and specimen geometry, the fatigue lives can be estimated for the laser-welded lap-shear specimens. The estimations are in good agreement with the experimental data. A classical solution for an infinitesimal kink is also employed in the approach. However, the life predictions tend to overestimate the actual fatigue lives. The traditional life estimations with the structural stress along with the experimental stress-fatigue life data (S-N curve) are also provided. In this case, the estimations only agree with the experimental data under higher load conditions.

  16. Lipid accumulation product (LAP) as a criterion for the identification of the healthy obesity phenotype in postmenopausal women.

    Science.gov (United States)

    Lwow, Felicja; Jedrzejuk, Diana; Milewicz, Andrzej; Szmigiero, Leszek

    2016-09-01

    Obesity and its complications constitute a major health problem in postmenopausal women. The identification of the obesity phenotype, especially that of metabolically healthy obese (MHO) patients, is a necessary part of obesity treatment protocols. There are several methods to define MHO, but unfortunately, all of them are arbitrary and inconsistent. The aim of this work was to determine whether lipid accumulation product (LAP) could be used as a marker of the MHO phenotype in postmenopausal women. A sample of 345 Polish postmenopausal women aged 50-60years old participated in the study. Participants were classified as obese when their BMI was >27. Receiver operating characteristic curve analysis was performed to estimate the best cutoff for the LAP index value to identify postmenopausal women without metabolic syndrome components. We found that the best cutoff value was LAP ≤29.9, and this value was used to define MHO individuals. With this definition, the identification of MHO individuals could be made when both of the following criteria were met: LAP index ≤29.9 and no arterial hypertension (SBPwomen identified according to the above definition, were compared with those of MHO women identified by two other methods in the literature. These methods and our definition identified similar proportions of MHO women ranging from 11.6% to 16.9%. We found that MHO women identified by all of the definitions used in this study possessed a similar metabolic status, and they did not differ in anthropometric indices or body fat distribution measurements. We concluded that the combination of LAP estimation and arterial blood pressure measurement appear to constitute a useful method for identifying the MHO phenotype in postmenopausal women. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Joint diseases

    International Nuclear Information System (INIS)

    Weissman, S.D.

    1989-01-01

    The authors discuss how x-ray examination is essential in the diagnosis and evaluation of the arthritides. Most arthritides are first suspected by the clinician, and x-ray evaluation of these entities along with laboratory testing is important for confirmation of the clinical diagnosis and in staging of the disease process. Several arthritides are often diagnosed first by the podiatrist on x-ray evaluation, including pseudogout, ankylosing spondylitis, early rheumatoid arthritis, degenerative joint disease, and tuberculosis of bone. The joint responds to insult in only a limited number of ways that become apparent on x-ray. The soft tissues surrounding the joint, the articulating bones, and alignment of the joint space may all be involved by the arthritic process. On roentgenographic examination, the soft tissues must be examined for edema, masses, calcifications, and atrophy. The articulating bones must be examined for demineralization, erosions, osteophytes, periosteal reaction, cysts and sclerosis

  18. Joint pain

    Science.gov (United States)

    ... or conditions. It may be linked to arthritis , bursitis , and muscle pain . No matter what causes it, ... Autoimmune diseases such as rheumatoid arthritis and lupus Bursitis Chondromalacia patellae Crystals in the joint: Gout (especially ...

  19. Joint Commission

    Science.gov (United States)

    ... for the latest publication of The Joint Commission Journal on Quality and Patient Safety (JQPS). . How We Work Process improvement program breeds quality culture, empowers staff An article in Quality Progress, June ...

  20. The Balance of Th1/Th2 and LAP+Tregs/Th17 Cells Is Crucial for Graft Survival in Allogeneic Corneal Transplantation

    Directory of Open Access Journals (Sweden)

    Shang Li

    2018-01-01

    Full Text Available Purpose. CD4+LAP+ T cells are newly discovered regulatory T cells (Tregs. The aim of this study is to investigate the balance of Th1/Th2 and LAP+Tregs/Th17 in mice after allogeneic corneal transplantation. Methods. A total of 65 mice received orthotopic penetrating transplantation. According to the survival scores of the grafts, the mice were divided into the rejection group and the survival group 3 weeks after transplantation. Th1, Th2, Th17, and regulatory T cells in the ipsilateral drainage lymph nodes and spleens were measured with flow cytometry. The related cytokines in aqueous humor were also analyzed. Results. The frequencies of Foxp3+Tregs, GARP+Tregs, and LAP+Tregs in the survival group were significantly higher than those in the rejection group. And the expression trend of CD4+LAP+ T cells and CD4+GARP+ T cells was consistent. The level of IFN-γ, TNF, IL-6, and IL-17A markedly increased in aqueous humor during corneal allograft rejection. The ratio of Th1/Th2 and Th17/LAP+Tregs significantly increased in the rejection group at the 3rd week after corneal transplantation. Conclusion. LAP+Tregs might be regarded as substitute for Foxp3+Tregs. The balance of Th1/Th2 and LAP+Tregs/Th17 is crucial for corneal allograft survival.

  1. Induction of polyploidy by nuclear fusion mechanism upon decreased expression of the nuclear envelope protein LAP2β in the human osteosarcoma cell line U2OS.

    Science.gov (United States)

    Ben-Shoshan, Shirley Oren; Simon, Amos J; Jacob-Hirsch, Jasmine; Shaklai, Sigal; Paz-Yaacov, Nurit; Amariglio, Ninette; Rechavi, Gideon; Trakhtenbrot, Luba

    2014-01-28

    Polyploidy has been recognized for many years as an important hallmark of cancer cells. Polyploid cells can arise through cell fusion, endoreplication and abortive cell cycle. The inner nuclear membrane protein LAP2β plays key roles in nuclear envelope breakdown and reassembly during mitosis, initiation of replication and transcriptional repression. Here we studied the function of LAP2β in the maintenance of cell ploidy state, a role which has not yet been assigned to this protein. By knocking down the expression of LAP2β, using both viral and non-viral RNAi approaches in osteosarcoma derived U2OS cells, we detected enlarged nuclear size, nearly doubling of DNA content and chromosomal duplications, as analyzed by fluorescent in situ hybridization and spectral karyotyping methodologies. Spectral karyotyping analyses revealed that near-hexaploid karyotypes of LAP2β knocked down cells consisted of not only seven duplicated chromosomal markers, as could be anticipated by genome duplication mechanism, but also of four single chromosomal markers. Furthermore, spectral karyotyping analysis revealed that both of two near-triploid U2OS sub-clones contained the seven markers that were duplicated in LAP2β knocked down cells, whereas the four single chromosomal markers were detected only in one of them. Gene expression profiling of LAP2β knocked down cells revealed that up to a third of the genes exhibiting significant changes in their expression are involved in cancer progression. Our results suggest that nuclear fusion mechanism underlies the polyploidization induction upon LAP2β reduced expression. Our study implies on a novel role of LAP2β in the maintenance of cell ploidy status. LAP2β depleted U2OS cells can serve as a model to investigate polyploidy and aneuploidy formation by nuclear fusion mechanism and its involvement in cancerogenesis.

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

    Directory of Open Access Journals (Sweden)

    Hubert Cecotti

    2014-09-01

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

  3. Joint Intentionality

    Directory of Open Access Journals (Sweden)

    Koreň Ladislav

    2016-03-01

    Full Text Available According to the shared intentionality hypothesis proposed by Michael Tomasello, two cognitive upgrades – joint and collective intentionality, respectively – make human thinking unique. Joint intentionality, in particular, is a mindset supposed to account for our early, species-specific capacity to participate in collaborative activities involving two (or a few agents. In order to elucidate such activities and their proximate cognitive-motivational mechanism, Tomasello draws on philosophical accounts of shared intentionality. I argue that his deference to such cognitively demanding accounts of shared intentional activities is problematic if his theoretical ambition is in part to show that and how early (prelinguistic and precultural capacities for joint action contribute to the development of higher cognitive capacities.

  4. German refrigeration sytems for Hong Kong Airport Chek Lap Kok and for Bangkok. Prause and Partner construct systems for Asia; Deutsche Kaeltetechnik fuer Hong Kongs Airport Chek Lap Kok, aber auch fuer Bangkok. Prause und Partner baut taifunsicher

    Energy Technology Data Exchange (ETDEWEB)

    Weissenborn, P.

    1998-09-01

    Hong Kong`s new airport Chek Lap Kok was commissioned on 6 July 1998 and is to become a turntable of air traffic in the Asian region. Prause and Partner, Goslar, will provide catering refrigeration systems for the airport. (orig.) [Deutsch] Hong Kongs neuer Airport Chek Lap Kok wird sich nach seiner Inbetriebnahme am 6. Juli 1998 zu einer der wichtigsten Drehscheiben im Luftverkehr Asiens entwickeln. Millionen von Fluggaesten werden dann taeglich mit Bordspeisen verpflegt werden muessen, bei deren Zubereitung und Konservierung die Kaeltetechnik eine bedeutende Funktion einnimmt. Deutsches Ingenieurwesen und solide deutsche Handwerkstechnik tragen dazu bei, dass `Catering-Refrigeration made by Prause and Partner`, Goslar, auch die Airline-Logistik der LSG Hong Kong zuverlaessig stuetzt. (orig./MSK)

  5. Characteristics of solder joints under fatigue loads using piezomechanical actuation

    Science.gov (United States)

    Shim, Dong-Jin; Spearing, S. Mark

    2003-07-01

    Crack initiation and growth characteristics of solder joints under fatigue loads are investigated using piezomechanical actuation. Cracks in solder joints, which can cause failure in microelectronics components, are induced via piezoelectricity in piezo-ceramic bonded joints. Lead-zirconate-titanate ceramic plates and eutectic Sn-Pb solder bonded in a double-lap shear configuration are used in the investigation. Electric field across each piezo-ceramic plate is applied such that shear stresses/strains are induced in the solder joints. The experiments show that cracks initiate in the solder joints around defects such as voids and grow in length until they coalesce with other cracks from adjacent voids. These observations are compared with the similar thermal cycling tests from the literature to show feasibility and validity of the current method in investigating the fatigue characteristics of solder joints. In some specimens, cracks in the piezo-ceramic plates are observed, and failure in the specimens generally occurred due to piezo-ceramic plate fracture. The issues encountered in implementing this methodology such as low actuation and high processing temperatures are further discussed.

  6. Rationale and Design of the Reduce Elevated Left Atrial Pressure in Patients With Heart Failure (Reduce LAP-HF) Trial

    DEFF Research Database (Denmark)

    Hasenfuss, Gerd; Gustafsson, Finn; Kaye, David

    2015-01-01

    OBJECTIVE: Heart failure with preserved ejection fraction (HFpEF) is characterized by elevated left atrial pressure during rest and/or exercise. The Reduce LAP-HF (Reduce Elevated Left Atrial Pressure in Patients With Heart Failure) trial will evaluate the safety and performance of the Interatrial...... Shunt Device (IASD) System II, designed to directly reduce elevated left atrial pressure, in patients with HFpEF. METHODS: The Reduce LAP-HF Trial is a prospective, nonrandomized, open-label trial to evaluate a novel device that creates a small permanent shunt at the level of the atria. A minimum of 60...... patients with ejection fraction ≥40% and New York Heart Association functional class III or IV heart failure with a pulmonary capillary wedge pressure (PCWP) ≥15 mm Hg at rest or ≥25 mm Hg during supine bike exercise will be implanted with an IASD System II, and followed for 6 months to assess the primary...

  7. Joint imaging

    International Nuclear Information System (INIS)

    Hengst, W.

    1984-01-01

    Joint imaging is a proven diagnostic procedure which has become indispensable to the detection and treatment of different joint diseases in almost all disciplines. The method is suited for early diagnosis of joint affections both in soft tissue and bone which cannot be detected by X-ray or other procedures. The local activity accumulation depends on the rate of metabolism and is visualized in the scan, which in turn enables the extension and floridity of focal lesions to be evaluated and followed-up. Although joint scans may often give hints to probabilities relevant to differential diagnosis, the method is non-specific and only useful if based on the underlying clinical picture and X-ray finding, if possible. The radiation exposure is very low and does not represent a hazard in cases of adequate assessment of indication. In pregnant women and children the assessment of indication has to be based on very strict principles. The method is suited for out-patient diagnosis and can be applied in all installations equipped with a gamma camera and a technetium generator. (orig.) [de

  8. Joint purpose?

    DEFF Research Database (Denmark)

    Pristed Nielsen, Helene

    2013-01-01

    Starting from Crenshaw´s point that antiracism often fails to interrogate patriarchy and that feminism often reproduces racist practices (1991: 1252), this paper asks: What are the theoretical reasons for believing that feminism and anti-racism can be regarded as fighting for the joint purpose...

  9. A new and specific non-NMDA receptor antagonist, FG 9065, blocks L-AP4-evoked depolarization in rat cerebral cortex.

    Science.gov (United States)

    Sheardown, M J

    1988-04-13

    L(+)-AP4 (2-amino-4-phosphonobutyrate) depolarized slices of rat cerebral cortex, when applied following a 2 min priming application of quisqualate. This response diminishes with time and is not seen after NMDA application. A new selective non-N-methyl-D-aspartate (NMDA) antagonist, 6-cyano-7-nitro-2,3-dihydroxyquinoxaline (FG 9065), inhibits the L(+)-AP4 depolarization. It is argued that the response is mediated indirectly by postsynaptic quisqualate receptors.

  10. Helios, and not FoxP3, is the marker of activated Tregs expressing GARP/LAP.

    Science.gov (United States)

    Elkord, Eyad; Abd Al Samid, May; Chaudhary, Belal

    2015-08-21

    Regulatory T cells (Tregs) are key players of immune regulation/dysregulation both in physiological and pathophysiological settings. Despite significant advances in understanding Treg function, there is still a pressing need to define reliable and specific markers that can distinguish different Treg subpopulations. Herein we show for the first time that markers of activated Tregs [latency associated peptide (LAP) and glycoprotein A repetitions predominant (GARP, or LRRC32)] are expressed on CD4+FoxP3- T cells expressing Helios (FoxP3-Helios+) in the steady state. Following TCR activation, GARP/LAP are up-regulated on CD4+Helios+ T cells regardless of FoxP3 expression (FoxP3+/-Helios+). We show that CD4+GARP+/-LAP+ Tregs make IL-10 immunosuppressive cytokine but not IFN-γ effector cytokine. Further characterization of FoxP3/Helios subpopulations showed that FoxP3+Helios+ Tregs proliferate in vitro significantly less than FoxP3+Helios- Tregs upon TCR stimulation. Unlike FoxP3+Helios- Tregs, FoxP3+Helios+ Tregs secrete IL-10 but not IFN-γ or IL-2, confirming they are bona fide Tregs with immunosuppressive characteristics. Taken together, Helios, and not FoxP3, is the marker of activated Tregs expressing GARP/LAP, and FoxP3+Helios+ Tregs have more suppressive characteristics, compared with FoxP3+Helios- Tregs. Our work implies that therapeutic modalities for treating autoimmune and inflammatory diseases, allergies and graft rejection should be designed to induce and/or expand FoxP3+Helios+ Tregs, while therapies against cancers or infectious diseases should avoid such expansion/induction.

  11. Validation of a novel basic virtual reality simulator, the LAP-X, for training basic laparoscopic skills.

    Science.gov (United States)

    Kawaguchi, Koji; Egi, Hiroyuki; Hattori, Minoru; Sawada, Hiroyuki; Suzuki, Takahisa; Ohdan, Hideki

    2014-10-01

    Virtual reality surgical simulators are becoming popular as a means of providing trainees with an opportunity to practice laparoscopic skills. The Lap-X (Epona Medical, Rotterdam, the Netherlands) is a novel VR simulator for training basic skills in laparoscopic surgery. The objective of this study was to validate the LAP-X laparoscopic virtual reality simulator by assessing the face and construct validity in order to determine whether the simulator is adequate for basic skills training. The face and content validity were evaluated using a structured questionnaire. To assess the construct validity, the participants, nine expert surgeons (median age: 40 (32-45)) (>100 laparoscopic procedures) and 11 novices performed three basic laparoscopic tasks using the Lap-X. The participants reported a high level of content validity. No significant differences were found between the expert surgeons and the novices (Ps > 0.246). The performance of the expert surgeons on the three tasks was significantly better than that of the novices in all parameters (Ps training device.

  12. Endovascular management of lap belt-related abdominal aortic injury in a 9-year-old child.

    Science.gov (United States)

    Papazoglou, Konstantinos O; Karkos, Christos D; Kalogirou, Thomas E; Giagtzidis, Ioakeim T

    2015-02-01

    Blunt abdominal aortic trauma is a rare occurrence in children with only a few patients having been reported in the literature. Most such cases have been described in the context of lap belt injuries. We report a 9-year-old boy who suffered lap belt trauma to the abdomen during a high-speed road traffic accident resulting to the well-recognized pattern of blunt abdominal injury, that is, the triad of intestinal perforation, fractures of the lumbar spine, and abdominal aortic injury. The latter presented with lower limb ischemia due to dissection of the infrarenal aorta and right common iliac artery. Revascularization was achieved by endovascular means using 2 self-expanding stents in the infrarenal aorta and the right common iliac artery. This case is one of the few reports of lap belt-related acute traumatic abdominal aortic dissection in a young child and highlights the feasibility of endovascular management in the pediatric population. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Hsp65-producing Lactococcus lactis prevents experimental autoimmune encephalomyelitis in mice by inducing CD4+LAP+ regulatory T cells

    Science.gov (United States)

    Rezende, Rafael M.; Oliveira, Rafael P.; Medeiros, Samara R.; Gomes-Santos, Ana C.; Alves, Andrea C.; Loli, Flávia G.; Guimarães, Mauro A.F.; Amaral, Sylvia S.; da Cunha, André P.; Weiner, Howard L.; Azevedo, Vasco; Miyoshi, Anderson; Faria, Ana M.C.

    2013-01-01

    Heat shock proteins (Hsps) participate in the cellular response to stress and they are hiperexpressed in inflammatory conditions. They are also known to play a major role in immune modulation, controlling, for instance, autoimmune responses. In this study, we showed that oral administration of a recombinant Lactococcus lactis strain that produces and releases LPS-free Hsp65 prevented the development of experimental autoimmune encephalomyelitis (EAE) in C57BL/6 mice. This was confirmed by the reduced inflammatory cell infiltrate and absence of injury signs in the spinal cord. The effect was associated with reduced IL-17 and increased IL-10 production in mesenteric lymph node and spleen cell cultures. Hsp65-producing-L. lactis-fed mice had a remarkable increase in the number of natural and inducible CD4+Foxp3+ regulatory T (Treg) cells and CD4+LAP+ (Latency-associated peptide) Tregs - which express the membrane-bound TGF-β - in spleen, inguinal and mesenteric lymph nodes as well as in spinal cord. Moreover, many Tregs co-expressed Foxp3 and LAP. In vivo depletion of LAP+ cells abrogated the effect of Hsp65-producing L. lactis in EAE prevention and worsened disease in medium-fed mice. Thus, Hsp65-L.lactis seems to boost this critical regulatory circuit involved in controlling EAE development in mice. PMID:22939403

  14. [Endo-Lap method in the management of biliary lithiasis (gallbladder and common bile duct)].

    Science.gov (United States)

    Filip, V; Georgescu, St; Stanciu, C; Bălan, Gh; Târcoveanu, E; Neacşu, C N; Cîrdei, C; Drug, V L

    2004-01-01

    To present the results of the biliary endoscopic approach (ERCP) followed by laparoscopic cholecystectomy (LC) in the management of biliary lithiasis (gallbladder and common bile duct--CBD). From 1997 to March 2003 37 patients with biliary lithiasis were treated by endoscopic sphincterotomy (ES) with stone extraction, followed after 24-48 hours by LC. The indications for ERCP were presence of an obstructive jaundice (n=32) and a dilated CBD at the ultrasound examination (n=5). Selective biliary cannulation was obtained in 35 (94.6%) cases, in all of them with successful papillotomy. Stones were found in all patients. CBD clearances for calculi (from 1 to 8) was obtained in 33 of 35 patients (94.3%), the rest of 2 being managed by open laparotomy. Antibiotics were administrated in all patients. Laparoscopic cholecystectomy was performed after 24-48 hours, with one conversion (3%). Postoperative morbidity was 12.1%: 2 transitory pancreatic reactions and 2 wound infections. Endo-Lap method is a useful management alternative for combined gallbladder and CBD lithiasis. It has all the advantages of the two mini-invasive procedures (fast recovery, short hospitalization, low costs) and a less postoperative morbidity in patients with high risk.

  15. In temperature forming of friction stir lap welds in aluminium alloys

    Science.gov (United States)

    Bruni, Carlo; Cabibbo, Marcello; Greco, Luciano; Pieralisi, Massimiliano

    2018-05-01

    The objective of such investigation is the study in depth of the forming phase of welds realized on three sheet metal blanks in aluminium alloys by friction stir lap welding. Such forming phase was performed by upsetting at different constant forming temperatures varying from 200°C to 350°C with constant ram velocities of 0.01 and 0.1 mm/s. The temperature values were obtained by the use of heating strips applied on the upper tool and on the lower tool. It was observed an increase in the friction factor, acting at the upsetting tool-workpiece interface, with increasing temperature that is very useful in producing the required localized deformation with which to improve the weld. It was also confirmed that the forming phase allows to realize a required thickness in the weld area allowing to neglect the surficial perturbation produced by the friction stir welding tool shoulder. The obtained thickness could be subjected to springback when too low temperatures are considered.

  16. Creep simulation of adhesively bonded joints using modified generalized time hardening model

    Energy Technology Data Exchange (ETDEWEB)

    Sadigh, Mohammad Ali Saeimi [Azarbaijan Shahid Madani University, Tabriz (Iran, Islamic Republic of)

    2016-04-15

    Creep behavior of double lap adhesively bonded joints was investigated using experimental tests and numerical analysis. Firstly, uniaxial creep tests were carried out to obtain the creep characteristics and constitutive parameters of the adhesive at different stress and temperature levels. Generalized time hardening model was used to predict the creep behavior of the adhesive. This model was modified to simulate the creep behavior at different stress and temperature levels. Secondly, the developed model was used to simulate the creep behavior of bonded joints using finite element based numerical analysis. Creep deformations of the joints were measured experimentally and good agreement was observed in comparison with the results obtained using numerical simulation. Afterward, stress redistribution due to the creep along the adhesively bonded joint was obtained numerically. It was observed that temperature level had a significant effect on the stress redistribution along the adhesive thickness.

  17. Extensive Characterisation of Copper-clad Plates, Bonded by the Explosive Technique, for ITER Electrical Joints

    CERN Document Server

    Langeslag, S A E; Libeyre, P; Gung, C Y

    2015-01-01

    Cable-in-conduit conductors will be extensively implemented in the large superconducting magnet coils foreseen to confine the plasma in the ITER experiment. The design of the various magnet systems imposes the use of electrical joints to connect unit lengths of superconducting coils by inter-pancake coupling. These twin-box lap type joints, produced by compacting each cable end in into a copper - stainless steel bimetallic box, are required to be highly performing in terms of electrical and mechanical prop- erties. To ascertain the suitability of the first copper-clad plates, recently produced, the performance of several plates is studied. Validation of the bonded interface is carried out by determining microstructural, tensile and shear characteristics. These measure- ments confirm the suitability of explosion bonded copper-clad plates for an overall joint application. Additionally, an extensive study is conducted on the suitability of certain copper purity grades for the various joint types.

  18. Playground slide-related injuries in preschool children: increased risk of lower extremity injuries when riding on laps.

    Science.gov (United States)

    Jennissen, Charles A; Koos, Maggie; Denning, Gerene

    2018-04-10

    The purpose of this study was to better understand the factors associated with playground slide-related injuries in preschool children and to test the hypothesis that riding on laps increases the likelihood of lower extremity injuries. Playground slide-related injuries (product code 1242) in children ≤5 years of age treated in emergency departments from 2002 to 2015 were identified (N = 12,686) using the U.S. Consumer Product Safety Commission's National Electronic Injury Surveillance System (NEISS). Descriptive and comparative analyses, including chi-square testing and binary logistic regression, were performed. Based on NEISS stratified national sampling estimates, over 350,000 children ≤5 years of age were injured on slides from 2002 to 2015. Overall, 59% of the children were male, and 65% were white. Almost 60% of injuries occurred in parks or other public areas. The most frequent diagnosis was a fracture (36%); lacerations were 19% of the injuries. A higher proportion of musculoskeletal injuries were seen in toddlers < 3 years old as compared to those 3-5 years of age (p < 0.001). Injuries to the lower extremities increased in frequency as age decreased, whereas injuries to the upper extremities and head/neck/face were more common in older preschoolers. Children < 3 years of age were 12 times more likely to be identified from narratives as being on another person's lap at the time of injury. Children identified as being on a lap had an increased odds of injury to the lower extremity than to other body parts (OR 43.0, 95% confidence interval (CI) 32.0-58.0), and of lower leg/ankle fracture than fractures elsewhere (OR 49.5, 95% CI 31.7-77.4). Decreasing age was associated with a higher likelihood of being identified as sliding down on another person's lap and a higher likelihood of lower extremity injuries. Healthcare providers should be mindful of the potential for these slide-related injuries as they can result in a toddler's fracture of

  19. Experimental Investigation on High-Cycle Fatigue of Inconel 625 Superalloy Brazed Joints

    Science.gov (United States)

    Chen, Jianqiang; Demers, Vincent; Turner, Daniel P.; Bocher, Philippe

    2018-04-01

    The high-cycle fatigue performance and crack growth pattern of transient liquid phase-brazed joints in a nickel-based superalloy Inconel 625 were studied. Assemblies with different geometries and types of overlaps were vacuum-brazed using the brazing paste Palnicro-36M in conditions such as to generate eutectic-free joints. This optimal microstructure provides the brazed assemblies with static mechanical strength corresponding to that of the base metal. However, eutectic micro-constituents were observed in the fillet region of the brazed assembly due to an incomplete isothermal solidification within this large volume of filler metal. The fatigue performance increased significantly with the overlap distance for single-lap joints, and the best performance was found for double-lap joints. It was demonstrated that these apparent changes in fatigue properties according to the specimen geometry can be rationalized when looking at the fatigue data as a function of the local stress state at the fillet radii. Fatigue cracks were nucleated from brittle eutectic phases located at the surface of the fillet region. Their propagation occurred through the bimodal microstructure of fillet and the diffusion region to reach the base metal. High levels of crack path tortuosity were observed, suggesting that the ductile phases found in the microstructure may act as a potential crack stopper. The fillet region must be considered as the critical region of a brazed assembly for fatigue applications.

  20. The Plastic Deformation of RFSSW Joints During Tensile Tests / Deformacja Plastyczna Wybranych Połączeń RFSSW Podczas Rozciągania

    Directory of Open Access Journals (Sweden)

    Lacki P.

    2015-12-01

    Full Text Available The dynamic development of the friction stir welding (FSW technology is the basis for the design of durabe joints inter alia in the aviation industry. This technology has a prospective application, especially for the aluminum alloys. It is suitable for a broad spectrum of permanent joints. The joints obtained by FSW technology are characterized by good mechanical properties. In this paper, the friction stir spot welding joints were analysed. The example of a structure made using this technology were presented. The lap joints made of 2mm Al 6061-T6 sheets were the investigation subject. The different spot welds arrangements were analysed. The tensile test were performed with optical deformation measurement system, which allow to obtain the plastic deformation field on the sample surface. The plastic strain graphs for the characteristic line passing through the maximum deformation were registered and presented. The experimental results were compared to the FEM numerical analysis. The numerical models were built with 3D-solid elements. The boundary conditions, material properties and geometry of the joints were identical as during experimental investigation. The mechanism of deformation of welded joints during tensile test was described and explained. It has been found that the arrangement of the spot welds with respect to the tensile direction has an important influence on the behaviour and deformation of lap joint.

  1. Joint Operation Planning

    National Research Council Canada - National Science Library

    2006-01-01

    .... It sets forth joint doctrine to govern the joint operation planning activities and performance of the Armed Forces of the United States in joint operations, and provides the joint doctrinal basis...

  2. LapOntoSPM: an ontology for laparoscopic surgeries and its application to surgical phase recognition.

    Science.gov (United States)

    Katić, Darko; Julliard, Chantal; Wekerle, Anna-Laura; Kenngott, Hannes; Müller-Stich, Beat Peter; Dillmann, Rüdiger; Speidel, Stefanie; Jannin, Pierre; Gibaud, Bernard

    2015-09-01

    The rise of intraoperative information threatens to outpace our abilities to process it. Context-aware systems, filtering information to automatically adapt to the current needs of the surgeon, are necessary to fully profit from computerized surgery. To attain context awareness, representation of medical knowledge is crucial. However, most existing systems do not represent knowledge in a reusable way, hindering also reuse of data. Our purpose is therefore to make our computational models of medical knowledge sharable, extensible and interoperational with established knowledge representations in the form of the LapOntoSPM ontology. To show its usefulness, we apply it to situation interpretation, i.e., the recognition of surgical phases based on surgical activities. Considering best practices in ontology engineering and building on our ontology for laparoscopy, we formalized the workflow of laparoscopic adrenalectomies, cholecystectomies and pancreatic resections in the framework of OntoSPM, a new standard for surgical process models. Furthermore, we provide a rule-based situation interpretation algorithm based on SQWRL to recognize surgical phases using the ontology. The system was evaluated on ground-truth data from 19 manually annotated surgeries. The aim was to show that the phase recognition capabilities are equal to a specialized solution. The recognition rates of the new system were equal to the specialized one. However, the time needed to interpret a situation rose from 0.5 to 1.8 s on average which is still viable for practical application. We successfully integrated medical knowledge for laparoscopic surgeries into OntoSPM, facilitating knowledge and data sharing. This is especially important for reproducibility of results and unbiased comparison of recognition algorithms. The associated recognition algorithm was adapted to the new representation without any loss of classification power. The work is an important step to standardized knowledge and data

  3. A new design of the LAPS land surface scheme for use over and through heterogeneous and non-heterogeneous surfaces: Numerical simulations and tests

    Science.gov (United States)

    Mihailovic, Dragutin T.; Lazic, Jelena; Leśny, Jacek; Olejnik, Janusz; Lalic, Branislava; Kapor, Darko; Cirisan, Ana

    2010-05-01

    Numerical simulations and tests with the recently redesigned land-air parameterization scheme (LAPS) are presented. In all experiments, supported either by one-point micrometeorological, 1D or 3D simulations, the attention has been directed to: (1) comparison of simulation outputs, expressing the energy transfer over and through heterogeneous and non-heterogeneous surfaces, versus observations and (2) analysis of uncertainties occurring in the solution of the energy balance equation at the land-air interface. To check the proposed method for aggregation of albedo, "propagating hole" sensitivity tests with LAPS over a sandstone rock grid cell have been performed with the forcing meteorological data for July 17, 1999 in Baxter site, Philadelphia (USA). Micrometeorological and biophysical measurements from the surface experiments conducted over crops and apple orchard in Serbia, Poland, Austria and France were used to test the operation of LAPS in calculating surface fluxes and canopy environment temperatures within and above plant covers of different densities. In addition, sensitivity tests with single canopy covers over the Central Europe region and comparison against the observations taken from SYNOP data using 3D simulations were made. Validation of LAPS performances over a solid surface has been done by comparison of 2 m air temperature observations against 5-day simulations over the Sahara Desert rocky ground using 3D model. To examine how realistically the LAPS simulates surface processes over a heterogeneous surface, we compared the air temperature measured at 2 m and that predicted by the 1D model with the LAPS as the surface scheme. Finally, the scheme behaviour over urban surface was tested by runs over different parts of a hypothetical urban area. The corresponding 1D simulations were carried out with an imposed meteorological dataset collected during HAPEX-MOBILHY experiment at Caumont (France). The quantities predicted by the LAPS compare well with the

  4. Lipid Accumulation Product (LAP) and Visceral Adiposity Index (VAI) as Markers of Insulin Resistance and Metabolic Associated Disturbances in Young Argentine Women with Polycystic Ovary Syndrome.

    Science.gov (United States)

    Abruzzese, Giselle A; Cerrrone, Gloria E; Gamez, Juan M; Graffigna, Mabel N; Belli, Susana; Lioy, Gustavo; Mormandi, Eduardo; Otero, Patricia; Levalle, Oscar A; Motta, Alicia B

    2017-01-01

    Polycystic ovary syndrome (PCOS) is an endocrine disorder. PCOS women are at high risk of developing insulin resistance (IR) and cardiovascular disorders since young age. We aimed to study the reliability of lipid accumulation product (LAP) and visceral adiposity index (VAI) as markers of metabolic disturbances (MD) associated with IR in young reproductive aged PCOS patients. We also evaluated the association between LAP and VAI and the presence of hyperandrogenism. In a cross-sectional study, 110 PCOS patients and 88 control women (18-35 years old) were recruited. PCOS patients were divided into 2 groups, as hyperandrogenic and non-hyperandrogenic considering the signs of hyperandrogenism (clinical or biochemical). Anthropometric measurements were taken and blood samples collected. Metabolic and anthropometric characteristics and their association with IR and associated MD were evaluated and LAP and VAI were calculated. LAP and VAI were compared with TC/HDL-c and TG/HDL-c to define the best markers of MD in this population. Independently of the phenotype, young PCOS patients showed high IR and dyslipidemia. Both LAP and VAI showed to be more effective markers to assess MD and IR in these young women than TG/HDL-c or TC/HDL-c [cut-off values: LAP: 18.24 (sensitivity: 81.43% specificity: 73.49%), positive predictive value (PPV): 75.0%, negative predictive value (NPV): 77.27%, VAI: 2.19 (sensitivity: 81.16% specificity: 72.15% PPV: 74.65% NPV: 72.22%)]. LAP and VAI are representative markers to assess MD associated with IR in young PCOS patients. All PCOS patients, independently of their androgenic condition, showed high metabolic risk. © Georg Thieme Verlag KG Stuttgart · New York.

  5. Multi-Scale Computational Modeling of Ni-Base Superalloy Brazed Joints for Gas Turbine Applications

    Science.gov (United States)

    Riggs, Bryan

    , ductile a-Ni phase that formed at the joint interface and a hard, brittle multi-phase centerline eutectic. CrB and Ni3B type borides were identified in the eutectic region via electron probe micro-analysis, and a boron diffusion gradient was observed in the BM adjacent to the joint. The volume fraction of centerline eutectic was found to be highly dependent on the extent of the boron diffusion that occurred during brazing and therefore a function of the primary process parameters; hold time, temperature, FM/BM composition, and joint gap. Thermo-Calc(TM) and DICTRA(TM) simulations were used to model the BM dissolution, isothermal solidification and phase transformations that occurred during brazing to predict the final joint microstructure based on these process parameters. Good agreement was found between experimental and simulated joint microstructures at various joint gaps demonstrating the application of these simulations for brazed joints. However, thermodynamic/kinetic databases available for brazing FMs were limited. A variety of mechanical testing was performed to determine the mechanical properties of CMSX-4/BNi-2 and IN718/BNi-2 brazed joints including small-scale tensile tests, standard-size butt joints and lap shear tests. Small-scale tensile testing provided a novel method for studying microstructure-property relationships in brazed joints and indicated that both joint strength and ductility decrease significantly with an increase in the volume fraction of centerline eutectic. In-situ observations during small-scale testing also showed strain localization and crack initiation occurs around the hard, eutectic phases in the joint microstructure during loading. The average tensile strength for standard-size IN718/BNi-2 butt joints containing a low volume fraction of centerline eutectic was found to be 152.8 ksi approximately 90% of the BM yield strength (˜170 ksi). The average lap shear FM stress was found to decrease from 70 to 20 ksi for IN718/BNi-2 joints and

  6. Lap shear strength of selected adhesives (epoxy, varnish, B-stage glass cloth) in liquid nitrogen and at room temperature

    International Nuclear Information System (INIS)

    Froelich, K.J.; Fitzpatrick, C.M.

    1976-12-01

    The adhesives included several epoxy resins, a varnish, and a B-stage glass cloth (a partially cured resin in a fiberglass cloth matrix). Several parameters critical to bond strength were varied: adhesive and adherend differences, surface preparation, coupling agents, glass cloth, epoxy thickness, fillers, and bonding pressure and temperature. The highest lap shear strengths were obtained with the B-shear glass cloth at both liquid nitrogen and room temperatures with values of approximately 20 MPa (3000 psi) and approximately 25.5 MPa (3700 psi) respectively

  7. Amistades Internacionales como contribución a la paz. La correspondencia entre Paul Rivet y Theodor Koch - Grünberg en el contexto de la Primera Guerra Mundial.

    Directory of Open Access Journals (Sweden)

    Michael Kraus.

    2010-07-01

    Full Text Available This article analyzes the correspondence between the French anthropologist paul rivet (1876-1958, and the german anthropologist theodor Koch-grünberg (1872-1924 after the First World War. the letters illustrate how both anthropologists struggled to reactivate the scientifc exchange between the two nations which had been interrupted by the war. their interest in common research themes, which had always transcended their national borders, established a collaborative attempt to overcome hostility and further appreciate international discourses over national ideologies.

  8. Effect of confinement on bond strength of hot-dip galvanized lap splices in concrete structures

    International Nuclear Information System (INIS)

    Fakhran, Mazen

    2004-01-01

    Galvanizing the reinforcing steel is one of the methods used to protect bars against corrosion. Galvanizing is a hot dip process where the reinforcing bars are immersed in an aqueous pre flux solution of zinc ammonium chloride at a controlled temperature between 840 and 850 degrees F. In 2001, a research program was started at AUB to evaluate experimentally the effect of hot dip galvanizing on the bond capacity of tension lap splices anchored in full-scale beam specimens designed to fail in bond splitting mode. The test results indicated that the use of galvanized bars had a negligible effect on bond strength of reinforcement in normal strength. However, galvanizing caused an average of 20 percent decrease in bond strength of reinforcement in high strength concrete. The primary objective of research reported in this thesis, is the need to find a solution to eliminate the bond reduction of galvanized bars in high strength concrete. It is significant to evaluate the positive effect of the addition of transverse reinforcement in the splice region. The hypothesis to be tested is that such transverse reinforcement will insure uniform bond stress distribution over the entire splice region, thus mobilizing all bar lugs along the splice in the stress transfer mechanism between the bar and the surrounding concrete. Such mechanism might reduce the significant decrease in bond strength in high strength concrete due to galvanizing. To achieve this objective, eighteen full-scale beam specimens were tested in positive bending. Each beam was reinforced with bars spliced in a constant moment region at midspam. The splice length was chosen in such a way that the beams failed in bond splitting of the concrete cover in the splice region. The main variables were type of coating (black or galvanized bars), bar size (20, 25 and 32 mm), and amount of transverse reinforcement in the splice region (0, 2 or 4 stirrups). The test results indicated that confinement did not have a significant

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

    Science.gov (United States)

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

    1992-01-01

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

  10. Study on Fatigue Performance of Composite Bolted Joints with Bolt-Hole Delamination

    Science.gov (United States)

    Liu, M. J.; Yu, S.; Zhao, Q. Y.

    2018-03-01

    Fatigue performance of composite structure with imperfections is a challenging subject at present. Based on cohesive zone method and multi-continuum theory, delamination evolution response and fatigue life prediction of a 3D composite single-lap joint with a bolt-hole have been investigated through computer codes Abaqus and Fe-safe. Results from the comparison of a perfect composite bolted joint with another defect one indicates that a relatively small delamination damage around the bolt hole brings about significant degradation of local material performance. More notably, fatigue life of stress concentration region of composite bolted joints is highly sensitive to external loads, as an increase of 67% cyclic load amplitude leads to an decrease of 99.5% local fatigue life in this study. However, the numerical strategy for solving composite fatigue problems is meaningful to engineering works.

  11. THE EFFECT OF DEGREASING ON ADHESIVE JOINT STRENGTH

    Directory of Open Access Journals (Sweden)

    Anna Rudawska

    2017-03-01

    Full Text Available The paper investigates the effect of degreasing, a surface preparation methods in adhesive bonding, on adhesive joint strength. 5 types of degreasing agents were used in the study: acetone, extraction naphtha, Ultramyt, Wiko and Loctite 7061. The degreasing operation was performed by three methods: rubbing, spraying and immersion. Strength tests were performed on single-lap adhesive joints of hot-dip galvanized metal sheets made with Loctite 9466 adhesive according to the above variants of surface preparation. The experimental results demonstrate that adhesive joint strength is significantly affected by the applied degreasing agent. Moreover, the method of application of the degreasing agent is crucial, too. The results of strength testing reveal that the most effective degreasing method for hot-dip galvanized metal sheet adhesive joints is spraying using extraction naphtha. Thereby degreased samples have the highest immediate strength and shear strength. The use of extraction naph-tha is also effective in combination with degreasing by rubbing; however, it is not effective when used in combi-nation with immersion, as reflected in the lowest strength results.

  12. Influence of the Aluminium Alloy Type on Defects Formation in Friction Stir Lap Welding of Thin Sheets

    Directory of Open Access Journals (Sweden)

    M. I. Costa

    Full Text Available Abstract The weldability in Friction Stir Lap Welding (FSLW of heat and non-heat treatable aluminium alloys, the AA6082-T6 and the AA5754-H22 aluminium alloys, respectively, are compared. For both alloys, welds were produced in very thin sheets, using the same welding parameters and procedures, and strong differences in welds morphology were found. The strength of the welds was evaluated by performing tensile-shear tests under monotonic and cyclic loading conditions. As-welded and heat-treated samples of the AA6082- T6 were tested. It was found that the heat-treatable alloy is more sensitive to defects formation, in lap welding, than the non-heat-treatable alloy. The presence of defects has a strong influence on the monotonic and fatigue behaviour of the welds. In spite of this, for very high-applied stresses, the heat-treatable alloy welds perform better in fatigue than the non-heat-treatable alloy welds.

  13. Transcriptional regulation of miR-146b by C/EBPβ LAP2 in esophageal cancer cells

    International Nuclear Information System (INIS)

    Li, Junxia; Shan, Fabo; Xiong, Gang; Wang, Ju-Ming; Wang, Wen-Lin; Xu, Xueqing; Bai, Yun

    2014-01-01

    Highlights: • MiR-146b promotes esophageal cancer cell proliferation. • MiR-146b inhibits esophageal cancer cell apoptosis. • C/EBPβ directly binds to miR-146b promoter conserved region. • MiR-146b is up-regulated by C/EBPβ LAP2 transcriptional activation. - Abstract: Recent clinical study indicated that up-regulation of miR-146b was associated with poor overall survival of patients in esophageal squamous cell carcinoma. However, the underlying mechanism of miR-146b dysregulation remains to be explored. Here we report that miR-146b promotes cell proliferation and inhibits cell apoptosis in esophageal cancer cell lines. Mechanismly, two C/EBPβ binding motifs are located in the miR-146b promoter conserved region. Among the three isoforms of C/EBPβ, C/EBPβ LAP2 positively regulated miR-146b expression and increases miR-146b levels in a dose-dependent manner through transcription activation of miR-146b gene. Together, these results suggest a miR-146b regulatory mechanism involving C/EBPβ, which may contribute to the up-regulation of miR-146b in esophageal squamous cell carcinoma

  14. Sensitivity Analysis of the Artificial Neural Network Outputs in Friction Stir Lap Joining of Aluminum to Brass

    Directory of Open Access Journals (Sweden)

    Mohammad Hasan Shojaeefard

    2013-01-01

    Full Text Available Al-Mg and CuZn34 alloys were lap joined using friction stir welding while the aluminum alloy sheet was placed on the CuZn34. In addition, the mechanical properties of each sample were characterized using shear tests. Scanning electron microscopy (SEM and X-ray diffraction analysis were used to probe chemical compositions. An artificial neural network model was developed to simulate the correlation between the Friction Stir Lap Welding (FSLW parameters and mechanical properties. Subsequently, a sensitivity analysis was performed to investigate the effect of each input parameter on the output in terms of magnitude and direction. Four methods, namely, the “PaD” method, the “Weights” method, the “Profile” method, and the “backward stepwise” method, which can give the relative contribution and/or the contribution profile of the input factors, were compared. The PaD method, giving the most complete results, was found to be the most useful, followed by the Profile method that gave the contribution profile of the input variables.

  15. Joint Instability and Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Darryl Blalock

    2015-01-01

    Full Text Available Joint instability creates a clinical and economic burden in the health care system. Injuries and disorders that directly damage the joint structure or lead to joint instability are highly associated with osteoarthritis (OA. Thus, understanding the physiology of joint stability and the mechanisms of joint instability-induced OA is of clinical significance. The first section of this review discusses the structure and function of major joint tissues, including periarticular muscles, which play a significant role in joint stability. Because the knee, ankle, and shoulder joints demonstrate a high incidence of ligament injury and joint instability, the second section summarizes the mechanisms of ligament injury-associated joint instability of these joints. The final section highlights the recent advances in the understanding of the mechanical and biological mechanisms of joint instability-induced OA. These advances may lead to new opportunities for clinical intervention in the prevention and early treatment of OA.

  16. Joint instability and osteoarthritis.

    Science.gov (United States)

    Blalock, Darryl; Miller, Andrew; Tilley, Michael; Wang, Jinxi

    2015-01-01

    Joint instability creates a clinical and economic burden in the health care system. Injuries and disorders that directly damage the joint structure or lead to joint instability are highly associated with osteoarthritis (OA). Thus, understanding the physiology of joint stability and the mechanisms of joint instability-induced OA is of clinical significance. The first section of this review discusses the structure and function of major joint tissues, including periarticular muscles, which play a significant role in joint stability. Because the knee, ankle, and shoulder joints demonstrate a high incidence of ligament injury and joint instability, the second section summarizes the mechanisms of ligament injury-associated joint instability of these joints. The final section highlights the recent advances in the understanding of the mechanical and biological mechanisms of joint instability-induced OA. These advances may lead to new opportunities for clinical intervention in the prevention and early treatment of OA.

  17. Bio-inspired design of geometrically interlocked 3D printed joints

    Science.gov (United States)

    Kumar, S.; Oliva, Noel; Kumar's Lab Team

    The morphology of the adhesive-adherend interface significantly affects the mechanical behavior of adhesive joints. As seen in some biocomposites like human skull, or the nacre of some bivalve molluscs' shells, a geometrically interlocking architecture of interfaces creates toughening and strengthening mechanisms enhancing the mechanical properties of the joint. In an attempt to characterize this mechanical interlocking mechanism, this study is focused on computational and experimental investigation of a single-lap joint with a very simple geometrically interlocked interface design in which both adherends have a square waveform configuration of the joining surfaces. This square waveform configuration contains a positive and a negative rectangular teeth per cycle in such a way that the joint is symmetric about the mid-bondlength. Both physical tests performed on 3D printed prototypes of joints and computational results indicate that the joints with square waveform design have higher strength and damage tolerance than those of joints with flat interface. In order to identify an optimal design configuration of this interface, a systematic parametric study is conducted by varying the geometric and material properties of the non-flat interface. This work was supported by Lockheed Martin (Award No: 12NZZ1).

  18. Cross-talk between miR-471-5p and autophagy component proteins regulates LC3-associated phagocytosis (LAP) of apoptotic germ cells.

    Science.gov (United States)

    Panneerdoss, Subbarayalu; Viswanadhapalli, Suryavathi; Abdelfattah, Nourhan; Onyeagucha, Benjamin C; Timilsina, Santosh; Mohammad, Tabrez A; Chen, Yidong; Drake, Michael; Vuori, Kristiina; Kumar, T Rajendra; Rao, Manjeet K

    2017-09-19

    Phagocytic clearance of apoptotic germ cells by Sertoli cells is vital for germ cell development and differentiation. Here, using a tissue-specific miRNA transgenic mouse model, we show that interaction between miR-471-5p and autophagy member proteins regulates clearance of apoptotic germ cells via LC3-associated phagocytosis (LAP). Transgenic mice expressing miR-471-5p in Sertoli cells show increased germ cell apoptosis and compromised male fertility. Those effects are due to defective engulfment and impaired LAP-mediated clearance of apoptotic germ cells as miR-471-5p transgenic mice show lower levels of Dock180, LC3, Atg12, Becn1, Rab5 and Rubicon in Sertoli cells. Our results reveal that Dock180 interacts with autophagy member proteins to constitute a functional LC3-dependent phagocytic complex. We find that androgen regulates Sertoli cell phagocytosis by controlling expression of miR-471-5p and its target proteins. These findings suggest that recruitment of autophagy machinery is essential for efficient clearance of apoptotic germ cells by Sertoli cells using LAP.Although phagocytic clearance of apoptotic germ cells by Sertoli cells is essential for spermatogenesis, little of the mechanism is known. Here the authors show that Sertoli cells employ LC3-associated phagocytosis (LAP) by recruiting autophagy member proteins to clear apoptotic germ cells.

  19. Plant-based oral tolerance to hemophilia therapy employs a complex immune regulatory response including LAP+CD4+ T cells

    OpenAIRE

    Wang, Xiaomei; Su, Jin; Sherman, Alexandra; Rogers, Geoffrey L.; Liao, Gongxian; Hoffman, Brad E.; Leong, Kam W.; Terhorst, Cox; Daniell, Henry; Herzog, Roland W.

    2015-01-01

    Coadministering FIX orally and systemically induces tolerance via complex immune regulation, involving tolerogenic dendritic and T-cell subsets.Induced CD4+CD25−LAP+ regulatory T cells with increased IL-10 and TGF-β expression and CD4+CD25+ regulatory T cells suppress antibody formation against FIX.

  20. Oana M. Oprean, Romania’s Accession to the European Union and Its Impact on the Roma Minority (Saarbrűcken: LAP Lambert Academic Publishing, 2012

    Directory of Open Access Journals (Sweden)

    Henrieta Serban

    2013-03-01

    Full Text Available Review of the book by Oana M. Oprean Romania’s Accession to the European Union and Its Impact on the Roma Minority, Saarbrűcken, LAP Lambert Academic Publishing, 2012, ISBN 978-3-8465-8671-6, 73p.

  1. International joint ventures

    DEFF Research Database (Denmark)

    Sørensen, Karsten Engsig

    2001-01-01

    The article analysis problems connected with corporate joint ventures. Among others the possible conflicts between the joint venture agreement and the statutes of the companies is examined, as well as certain problems connected to the fact that the joint venture partners have created commen control...... over their joint company....

  2. An N-terminal Retention Module Anchors the Giant Adhesin LapA of Pseudomonas fluorescens at the Cell Surface: A Novel Sub-family of Type I Secretion Systems.

    Science.gov (United States)

    Smith, T Jarrod; Font, Maria E; Kelly, Carolyn M; Sondermann, Holger; O'Toole, George A

    2018-02-05

    LapA of Pseudomonas fluorescens Pf0-1 belongs to a diverse family of cell surface associated bacterial adhesins that are secreted via the type-1 secretion system (T1SS). We previously reported that the periplasmic protease LapG cleaves the N-terminus of LapA at a canonical dialanine motif to release the adhesin from the cell surface under conditions unfavorable to biofilm formation, thus decreasing biofilm formation. Here, we characterize LapA as the first type 1 secreted substrate that does not follow the "one-step" rule of T1SS. Rather, a novel N-terminal element, called the retention module (RM), localizes LapA at the cell surface as a secretion intermediate. Our genetic, biochemical, and molecular modeling analysis support a model wherein LapA is tethered to the cell surface through its T1SS outer membrane TolC-like pore, LapE, until LapG cleaves LapA in the periplasm. We further demonstrate this unusual retention strategy is likely conserved among LapA-like proteins, and reveals a new subclass of T1SS ABC transporters involved in transporting this group of surface-associated, LapA-like adhesins. These studies demonstrate a novel cell surface retention strategy used throughout the Proteobacteria and highlight a previously unappreciated flexibility of function for T1SS. Importance. Bacteria have evolved multiple secretion strategies to interact with their environment. For many bacteria, the secretion of cell surface associated adhesins is key for initiating contact with a preferred substratum to facilitate biofilm formation. Our work demonstrates that P. fluorescens uses a previously unrecognized secretion strategy to retain the giant adhesin LapA at its cell surface. Further, we identify likely LapA-like adhesins in various pathogenic and commensal Proteobacteria and provide phylogenetic evidence that these adhesins are secreted by a new subclass of T1SS ABC transporters. Copyright © 2018 American Society for Microbiology.

  3. Device for measuring hole elongation in a bolted joint

    Science.gov (United States)

    Wichorek, Gregory R. (Inventor)

    1987-01-01

    A device to determine the operable failure mode of mechanically fastened lightweight composite joints by measuring the hole elongation of a bolted joint is disclosed. The double-lap joint test apparatus comprises a stud, a test specimen having a hole, two load transfer plates, and linear displacement measuring instruments. The test specimen is sandwiched between the two load transfer plates and clamped together with the stud. Spacer washers are placed between the test specimen and each load transfer plate to provide a known, controllable area for the determination of clamping forces around the hole of the specimen attributable to bolt torque. The spacer washers also provide a gap for the mounting of reference angles on each side of the test specimen. Under tensile loading, elongation of the hole of the test specimen causes the stud to move away from the reference angles. This displacement is measured by the voltage output of two linear displacement measuring instruments that are attached to the stud and remain in contact with the reference angles throughout the tensile loading. The present invention obviates previous problems in obtaining specimen deformation measurements by monitoring the reference angles to the test specimen and the linear displacement measuring instruments to the stud.

  4. Study on Flow-Shifted Region Depending on Spool Displacement in Hydraulic Servo Valve with Hybrid Lap

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Hwanghun; Yun, Sonam; Lee, Sungsoo [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of); Yang, Jooho [Pukyong Nat' l Univ., Busan (Korea, Republic of)

    2013-03-15

    This study examined the static characteristics of a spool valve with a hybrid lap between the spool land and the sleeve. The static equation for the pressure characteristics was derived from flow equations that depend on the spool displacement, and the final model was derived from q{sub a}=q{sub b}=0 because the pressure characteristics test needs to block the control port in the valve. The static equation for the flow characteristics was derived from the pressure characteristics when the control port is open (q{sub a}=q{sub b}, p{sub a}=p{sub b}). The characteristic equation in the shifted region was assumed from the proportional relationship between the pressure-flow characteristics and the spool displacement.

  5. Effects of vertically aligned carbon nanotubes on shear performance of laminated nanocomposite bonded joints

    Directory of Open Access Journals (Sweden)

    Davood Askari and Mehrdad N Ghasemi-Nejhad

    2012-01-01

    Full Text Available The main objective is to improve the most commonly addressed weakness of the laminated composites (i.e. delamination due to poor interlaminar strength using carbon nanotubes (CNTs as reinforcement between the laminae and in the transverse direction. In this work, a chemical vapor deposition technique has been used to grow dense vertically aligned arrays of CNTs over the surface of chemically treated two-dimensionally woven cloth and fiber tows. The nanoforest-like fabrics can be used to fabricate three-dimensionally reinforced laminated nanocomposites. The presence of CNTs aligned normal to the layers and in-between the layers of laminated composites is expected to considerably enhance the properties of the laminates. To demonstrate the effectiveness of our approach, composite single lap-joint specimens were fabricated for interlaminar shear strength testing. It was observed that the single lap-joints with through-the-thickness CNT reinforcement can carry considerably higher shear stresses and strains. Close examination of the test specimens showed that the failure of samples with CNT nanoforests was completely cohesive, while the samples without CNT reinforcement failed adhesively. This concludes that the adhesion of adjacent carbon fabric layers can be considerably improved owing to the presence of vertically aligned arrays of CNT nanoforests.

  6. Effects of vertically aligned carbon nanotubes on shear performance of laminated nanocomposite bonded joints.

    Science.gov (United States)

    Askari, Davood; Ghasemi-Nejhad, Mehrdad N

    2012-08-01

    The main objective is to improve the most commonly addressed weakness of the laminated composites (i.e. delamination due to poor interlaminar strength) using carbon nanotubes (CNTs) as reinforcement between the laminae and in the transverse direction. In this work, a chemical vapor deposition technique has been used to grow dense vertically aligned arrays of CNTs over the surface of chemically treated two-dimensionally woven cloth and fiber tows. The nanoforest-like fabrics can be used to fabricate three-dimensionally reinforced laminated nanocomposites. The presence of CNTs aligned normal to the layers and in-between the layers of laminated composites is expected to considerably enhance the properties of the laminates. To demonstrate the effectiveness of our approach, composite single lap-joint specimens were fabricated for interlaminar shear strength testing. It was observed that the single lap-joints with through-the-thickness CNT reinforcement can carry considerably higher shear stresses and strains. Close examination of the test specimens showed that the failure of samples with CNT nanoforests was completely cohesive, while the samples without CNT reinforcement failed adhesively. This concludes that the adhesion of adjacent carbon fabric layers can be considerably improved owing to the presence of vertically aligned arrays of CNT nanoforests.

  7. Electroacupuncture for postoperative pain and gastrointestinal motility after laparoscopic appendectomy (AcuLap): study protocol for a randomized controlled trial.

    Science.gov (United States)

    Kim, Gangmi

    2015-10-14

    Acupuncture is a widely serviced complementary medicine. Although acupuncture is suggested for managing postoperative ileus and pain, supporting evidence is weak. The AcuLap trial is designed to provide high-level evidence regarding whether or not electroacupuncture is effective in promoting gastrointestinal motility and controlling pain after laparoscopic surgery. This study is a prospective randomized controlled trial with a three-arm, parallel-group structure evaluating the efficacy of electroacupuncture for gastrointestinal motility and postoperative pain after laparoscopic appendectomy. Patients with appendicitis undergoing laparoscopic surgery are included and randomized into three groups: 1) electroacupuncture group, 2) sham acupuncture group, and 3) control group. Patients receive 1) acupuncture with electrostimulation or 2) fake electroacupuncture with sham device twice a day or 3) no acupuncture after laparoscopic appendectomy. The primary outcome is time to first passing flatus after operation. Secondary outcomes include postoperative pain, analgesics, nausea/vomiting, bowel motility, time to tolerable diet, complications, hospital stay, readmission rates, time to recovery, quality of life, medical costs, and protocol failure rate. Patients and hospital staff (physicians and nurses) are blinded to which group the patient is assigned, electroacupuncture or sham acupuncture. Data analysis personnel are blinded to group assignment among all three groups. Estimated sample size to detect a minimum difference of time to first flatus with 80 % power, 5 % significance, and 10 % drop rate is 29 × 3 groups = 87 patients. Analysis will be performed according to the intention-to-treat principle. The AcuLap trial will provide evidence on the merits and/or demerits of electroacupuncture for bowel motility recovery and pain relief after laparoscopic appendectomy. The trial was registered in Clinical Research Information Service (CRiS), Republic of Korea ( KCT0001486

  8. Investigation on dissimilar underwater friction stir lap welding of 6061-T6 aluminum alloy to pure copper

    International Nuclear Information System (INIS)

    Zhang, Jingqing; Shen, Yifu; Yao, Xin; Xu, Haisheng; Li, Bo

    2014-01-01

    Highlights: • 6061-T6 Al and pure Cu were successfully underwater friction stir lap welded. • The underwater weld was analyzed via comparing with the classical weld. • The oxidation of Cu was prevented via the external water. • The amount of Al–Cu intermetallic was decreased by the external water. • The thickness of Al–Cu diffusion interlayer was decreased by the external water. - Abstract: Friction stir welding (classical FSW) is considered to offer advantages over the traditional fusion welding techniques in terms of dissimilar welding. However, some challenges still exist in the dissimilar friction stir lap welding of the aluminum/copper (Al/Cu) metallic couple, among which the formation of the Al–Cu intermetallic compounds is the major problem. In the present research, due to the fact that the formation and growth of the intermetallic are significantly controlled by the thermal history, the underwater friction stir welding (underwater FSW) was employed for fabricating the weld, and the weld obtained by underwater FSW (underwater weld) was analyzed via comparing with the weld obtained under same parameters by classical FSW (classical weld). In order to investigate the effect of the external water on the thermal history, the K-type thermocouple was utilized to measure the weld temperature, and it is found that the water could decrease the peak temperature and shorten the thermal cycle time. The XRD results illustrate that the interface of the welds mainly consist of the Al–Cu intermetallic compounds such as CuAl 2 and Cu 9 Al 4 together with some amounts of Al and Cu, and it is also found that the amount of the intermetallic in the underwater weld is obvious less than in the classical weld. The SEM images and the EDS line scan results also illustrate that the Al–Cu diffusion interlayer at the Al–Cu interface of the underwater weld was obviously thinner than that of the classical weld

  9. Validation of SINERGIA as training tool: a randomized study to test the transfer of acquired basic psychomotor skills to LapMentor.

    Science.gov (United States)

    Moyano-Cuevas, J L; Sánchez-Margallo, F M; Sánchez-Peralta, L F; Pagador, J B; Enciso, S; Sánchez-González, P; Gómez-Aguilera, E J; Usón-Gargallo, J

    2011-11-01

    Laparoscopic surgery is commonly used in many surgical procedures but requires a learning process to develop the necessary skills. Virtual reality simulators play an essential role within the training curricula. This paper aims to determine whether training in SINERGIA VR simulator allows novice surgeons to improve their basic psychomotor laparoscopic skills. Forty-two people participated in this study, including 28 unexperience medical students and 14 expert surgeons who developed previously more than 100 laparoscopic procedures. Medical students made a pre-training test in LapMentor II; then, they trained in SINERGIA and they finally accomplished a post-training test in LapMentor II. Experts just made one trial in LapMentor II. A statistical analysis was carried out and results of pre- and post-training tests of novices were compared with Wilcoxon signed-rank test. Pre- and post-training tests of novices were also compared with results of experts with Mann-Whitney U test. Most metrics provided by LapMentor II and included in this study show significant differences when comparing pre- and post-training tests of novices. Analysis of pre-training test of novices and experts results show significant differences in all analyzed metrics for all studied tasks. On the other hand, LapMentor was not able to distinguish between experts and novices after training in SINERGIA for any metric in the camera manipulation task and for some metrics of the other tasks. Training in SINERGIA VR simulator allows improvement of basic psychomotor laparoscpic skills and transferring them to another virtual simulator. Therefore, it could be used in laparoscopic surgery training programs.

  10. High-power Laser Welding of Thick Steel-aluminum Dissimilar Joints

    Science.gov (United States)

    Lahdo, Rabi; Springer, André; Pfeifer, Ronny; Kaierle, Stefan; Overmeyer, Ludger

    According to the Intergovernmental Panel on Climate Change (IPCC), a worldwide reduction of CO2-emissions is indispensable to avoid global warming. Besides the automotive sector, lightweight construction is also of high interest for the maritime industry in order to minimize CO2-emissions. Using aluminum, the weight of ships can be reduced, ensuring lower fuel consumption. Therefore, hybrid joints of steel and aluminum are of great interest to the maritime industry. In order to provide an efficient lap joining process, high-power laser welding of thick steel plates (S355, t = 5 mm) and aluminum plates (EN AW-6082, t = 8 mm) is investigated. As the weld seam quality greatly depends on the amount of intermetallic phases within the joint, optimized process parameters and control are crucial. Using high-power laser welding, a tensile strength of 10 kN was achieved. Based on metallographic analysis, hardness tests, and tensile tests the potential of this joining method is presented.

  11. Loading and fracture response of CFRP-to-steel adhesively bonded joints with thick adherents – Part II: Numerical simulation

    DEFF Research Database (Denmark)

    Anyfantis, Konstantinos; Tsouvalis, Nicholas G.

    2013-01-01

    This work is focused on the numerical simulation of experimentally tested single lap joints, based on cohesive zone modeling techniques. Seven cases have been considered for analysis. The models were built in a 3-dimensional finite element space. The adherents were modeled with continuum elements...... the developed peel, in-plane and out-of-plane shear stresses over the adhesive area. Thus, the global measured response of all cases was justified by examining the stress fields and their variation through the loading history. © 2012 Elsevier Ltd. All rights reserved....

  12. Effect of the weld joint configuration on stressed components, residual stresses and mechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Cevik, Bekir; Oezer, Alpay; Oezcatalbas, Yusuf [Gazi Univ., Ankara (Turkey)

    2014-03-01

    The effect of the weld joint configuration on components has been studied, which are under service loads, under repair or construction and the residual stresses as well as the mechanical properties of the joint have been determined. For this purpose, a horizontal positioned tensile testing device and a semi-automatic MIG welding machine have been used and then the weld joints of the plates were subjected to different elastic stresses. When the temperature of the joined elements decreased to room temperature, applied elastic stresses were released. By this means, the effects of the existing tensile stresses in the joined parts and the tensile stresses created by the welding processes were investigated. The tensile stresses occurring in the joined elements were determined by using the photo-elasticity analysis method and the hole-drilling method. Also, tensile-shear tests were applied in order to determine the effect of permanent tensile loads on the mechanical properties of the joint. Experimental results showed that the application of corner welded lap joints for components under tensile loading significantly decrease the shear strength and yielding capacities of the joint. (orig.)

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

    International Nuclear Information System (INIS)

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

    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-mm 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

  14. Review of research on the hygrothermal environmental durability of structural adhesively bonded joints

    Directory of Open Access Journals (Sweden)

    Xiao HAN

    2017-06-01

    Full Text Available In recent years, structural adhesive bonding technology has been widely used in many industrial fields, with many advantages over traditional mechanical connection methods, such as riveting, welding and bolt connection. Due to the adhesive characteristics of polymer materials, the environmental durability of adhesive joint becomes the key problems in engineering structure connection feasibility and long-term service reliability. On the basis of the review of the research of the hot-humid environmental durability of structural adhesive joints, the effects of temperature, moisture and coupled condition on the structural mechanical behaviour are discussed, introducing the published research progress and results both at home and abroad. The prospects are provided: the future research work can be combined with a variety of observation scales of environmental aging test and numerical simulation method, delve into sub hygroscopic, creep, thermal expansion and hygroscopic expansion aging behavior, such as the environment of model prediction method simulation in more than a variety of mechanical performance degradation behavior of coupling conditions, and provide more reliable theoretical modeling and experimental data for engineering design and application of cementing structure.

  15. Microstructure and mechanical properties of resistance spot welded dissimilar thickness DP780/DP600 dual-phase steel joints

    International Nuclear Information System (INIS)

    Zhang, Hongqiang; Wei, Ajuan; Qiu, Xiaoming; Chen, Jianhe

    2014-01-01

    Highlights: • We examine changes of microstructure of dissimilar thickness DP600/DP780 joints. • The hardness profile of RSW joints can be predicted by the equation. • Failure modes, peak load and energy describes the mechanical properties of joints. • The nugget diameter is the key factor of transition between the failure modes. - Abstract: In this study, resistance spot welding (RSW) experiments were performed in order to evaluate the microstructure and mechanical properties of single-lap joints between DP780 and DP600. The results show that the weld joints consist of three regions including base metal (BM), heat affected zone (HAZ) and fusion zone (FZ). The grain size and martensite volume fractions increase in the order of BM, HAZ and FZ. The hardness in the FZ is significantly higher than hardness of base metals. Tensile properties of the joints were described in terms of the failure modes and static load-carrying capabilities. Two distinct failure modes were observed during the tensile shear test of the joints: interfacial failure (IF) and pullout failure (PF). The FZ size plays a dominate role in failure modes of the joints

  16. Joint Replacement (Finger and Wrist Joints)

    Science.gov (United States)

    ... All Topics A-Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is a Hand Surgeon? What is a Hand Therapist? Media Find a Hand Surgeon Home Anatomy Joint Replacement Email to a friend * required fields ...

  17. Hip joint injection

    Science.gov (United States)

    ... medicine into the joint. The provider uses a real-time x-ray (fluoroscopy) to see where to place ... Wakefield RJ. Arthrocentesis and injection of joints and soft tissue. In: Firestein GS, Budd RC, Gabriel SE, ...

  18. Sacroiliac joint pain - aftercare

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000610.htm Sacroiliac joint pain - aftercare To use the sharing features on this page, please enable JavaScript. The sacroiliac joint (SIJ) is a term used to describe ...

  19. Reliability of Tubular Joints

    DEFF Research Database (Denmark)

    Sørensen, John Dalsgaard; Thoft-Christensen, Palle

    In this paper the preliminary results obtained by tests on tubular joints are presented. The joints are T-joints and the loading is static. It is the intention in continuation of these tests to perform tests on other types of joints (e.g. Y-joints) and also with dynamic loading. The purpose...... of the test is partly to obtain empirical data for the ultimate load-carrying capacity of tubular T-joints and partly to obtain some experience in performing tests with tubular joints. It is well known that tubular joints are usually designed in offshore engineering on the basis of empirical formulas obtained...... by experimental test results. Therefore, there is a need for performing experimental tests in this area....

  20. Hip joint replacement - slideshow

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/presentations/100006.htm Hip joint replacement - series—Normal anatomy To use the ... to slide 5 out of 5 Overview The hip joint is made up of two major parts: ...

  1. Managing Joint Production Motivation

    DEFF Research Database (Denmark)

    Lindenberg, Siegwart; Foss, Nicolai Juul

    2011-01-01

    We contribute to the microfoundations of organizational performance by proffering the construct of joint production motivation. Under such motivational conditions individuals see themselves as part of a joint endeavor, each with his or her own roles and responsibilities; generate shared...... representations of actions and tasks; cognitively coordinate cooperation; and choose their own behaviors in terms of joint goals. Using goal-framing theory, we explain how motivation for joint production can be managed by cognitive/symbolic management and organizational design....

  2. Xenopus LAP2β protein knockdown affects location of lamin B and nucleoporins and has effect on assembly of cell nucleus and cell viability.

    Science.gov (United States)

    Dubińska-Magiera, Magda; Chmielewska, Magdalena; Kozioł, Katarzyna; Machowska, Magdalena; Hutchison, Christopher J; Goldberg, Martin W; Rzepecki, Ryszard

    2016-05-01

    Xenopus LAP2β protein is the single isoform expressed in XTC cells. The protein localizes on heterochromatin clusters both at the nuclear envelope and inside a cell nucleus. The majority of XLAP2β fraction neither colocalizes with TPX2 protein during interphase nor can be immunoprecipitated with XLAP2β antibody. Knockdown of the XLAP2β protein expression in XTC cells by synthetic siRNA and plasmid encoded siRNA resulted in nuclear abnormalities including changes in shape of nuclei, abnormal chromatin structure, loss of nuclear envelope, mislocalization of integral membrane proteins of INM such as lamin B2, mislocalization of nucleoporins, and cell death. Based on timing of cell death, we suggest mechanism associated with nucleus reassembly or with entry into mitosis. This confirms that Xenopus LAP2 protein is essential for the maintenance of cell nucleus integrity and the process of its reassembly after mitosis.

  3. Novel Ambler class A beta-lactamase LAP-1 and its association with the plasmid-mediated quinolone resistance determinant QnrS1.

    Science.gov (United States)

    Poirel, Laurent; Cattoir, Vincent; Soares, Ana; Soussy, Claude-James; Nordmann, Patrice

    2007-02-01

    The plasmid-mediated quinolone resistance determinant QnrS1 was identified in non-clonally related Enterobacter cloacae isolates in association with a transferable narrow-spectrum beta-lactam resistance marker. Cloning experiments allowed the identification of a novel Ambler class A beta-lactamase, named LAP-1. It shares 62 and 61% amino acid identity with the most closely related beta-lactamases, TEM-1 and SHV-1, respectively. It has a narrow-spectrum hydrolysis of beta-lactams and is strongly inhibited by clavulanic acid and sulbactam and, to a lesser extent, by tazobactam. Association of the blaLAP-1 gene with the qnrS1 gene was identified in E. cloacae isolates from France and Vietnam. These genes were plasmid located and associated with similar insertion sequences but were not associated with sul1-type class 1 integrons, as opposed to the qnrA genes.

  4. Characterization of waste of soda-lime glass generated from lapping process to reuse as filler in composite materials as thermal insulation

    Directory of Open Access Journals (Sweden)

    A. C. P. Galvão

    2015-09-01

    Full Text Available AbstractThe beneficiation plate process by soda-lime glass lapping in the glass industry generates, an untapped residue (waste. The waste of this material is sent to landfills, causing impact on the environment. This work aimed to characterize and evaluate the waste of soda-lime glass (GP lapping. After its acquisition, the GP was processed by grinding and sieving and further characterized by the chemical/mineralogical analysis (XRF, EDS and XRD, SEM morphology, particle size by laser diffraction, thermogravimetric analyses (TGA and DSC and thermophysical analyses. It was observed that the GP particles are irregular and micrometric with the predominant presence of Na, Si and Ca elements characteristic of amorphous soda-lime glass. The assessment of the chemical/mineralogical, morphological, thermophysical and thermal gravimetric characteristics of GP suggest its reuse as reinforcing fillers or filler in composite materials to obtain thermal insulation.

  5. Strength of joints brazed with two-phase solders

    International Nuclear Information System (INIS)

    Shnyakin, N.S.; Parfenova, L.V.; Ekatova, A.S.; Prilepskaya, I.V.

    1976-01-01

    Dependence of the structure and strength of soldered joints upon a gap size in case of 1Kh18N10T stainless steel soldering with a double-phase solder of Ni-Zn-Cu system is described. Butt and lap joints have been subjected to soldering with gas-flame and induction heating. The optimum conditions of the solder crystallization are determined with wedge-gap samples. The studies show that the character of distribution of a fusible β-phase in metal depends upon a gap size. With gaps up to 0.1 mm the β-phase enriched with a fusible component (zinc) runs as a continuous thin interlayer in the middle of the seam. As a result of zinc evaporation from the β-phase this interlayer becomes internally oxidized. After the sample is broken an oxidized fracture gives one the impression of a poor fusion in the middle part of the joint. The ultimate strength of butt joints is 15-20 kgf/sq.mm. A value of thermal expansion of 1Kh18N10T steel samples, 1-5 mm thick, has been experimentally determined for butt soldering. The elongation of two halves of the sample is measured by an indicator and proved to be 0.89 mm for a 50x50x2 mm sample at a soldering temperature of 1.100 deg C. The paper presents methods for the calculation of an optimal gap value for butt soldering with a local gas-flame and induction heating

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

    Science.gov (United States)

    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.

  7. The Fundamentals of Laparoscopic Surgery and LapVR evaluation metrics may not correlate with operative performance in a novice cohort

    Science.gov (United States)

    Steigerwald, Sarah N.; Park, Jason; Hardy, Krista M.; Gillman, Lawrence; Vergis, Ashley S.

    2015-01-01

    Background Considerable resources have been invested in both low- and high-fidelity simulators in surgical training. The purpose of this study was to investigate if the Fundamentals of Laparoscopic Surgery (FLS, low-fidelity box trainer) and LapVR (high-fidelity virtual reality) training systems correlate with operative performance on the Global Operative Assessment of Laparoscopic Skills (GOALS) global rating scale using a porcine cholecystectomy model in a novice surgical group with minimal laparoscopic experience. Methods Fourteen postgraduate year 1 surgical residents with minimal laparoscopic experience performed tasks from the FLS program and the LapVR simulator as well as a live porcine laparoscopic cholecystectomy. Performance was evaluated using standardized FLS metrics, automatic computer evaluations, and a validated global rating scale. Results Overall, FLS score did not show an association with GOALS global rating scale score on the porcine cholecystectomy. None of the five LapVR task scores were significantly associated with GOALS score on the porcine cholecystectomy. Conclusions Neither the low-fidelity box trainer or the high-fidelity virtual simulator demonstrated significant correlation with GOALS operative scores. These findings offer caution against the use of these modalities for brief assessments of novice surgical trainees, especially for predictive or selection purposes. PMID:26641071

  8. The Fundamentals of Laparoscopic Surgery and LapVR evaluation metrics may not correlate with operative performance in a novice cohort

    Directory of Open Access Journals (Sweden)

    Sarah N. Steigerwald

    2015-12-01

    Full Text Available Background: Considerable resources have been invested in both low- and high-fidelity simulators in surgical training. The purpose of this study was to investigate if the Fundamentals of Laparoscopic Surgery (FLS, low-fidelity box trainer and LapVR (high-fidelity virtual reality training systems correlate with operative performance on the Global Operative Assessment of Laparoscopic Skills (GOALS global rating scale using a porcine cholecystectomy model in a novice surgical group with minimal laparoscopic experience. Methods: Fourteen postgraduate year 1 surgical residents with minimal laparoscopic experience performed tasks from the FLS program and the LapVR simulator as well as a live porcine laparoscopic cholecystectomy. Performance was evaluated using standardized FLS metrics, automatic computer evaluations, and a validated global rating scale. Results: Overall, FLS score did not show an association with GOALS global rating scale score on the porcine cholecystectomy. None of the five LapVR task scores were significantly associated with GOALS score on the porcine cholecystectomy. Conclusions: Neither the low-fidelity box trainer or the high-fidelity virtual simulator demonstrated significant correlation with GOALS operative scores. These findings offer caution against the use of these modalities for brief assessments of novice surgical trainees, especially for predictive or selection purposes.

  9. Respectability, morality and disgust in the night‐time economy: exploring reactions to ‘lap dance’ clubs in England and Wales

    Science.gov (United States)

    Hubbard, Phil; Colosi, Rachela

    2015-01-01

    Abstract The night‐time economy is often described as repelling consumers fearful of the ‘undesirable Others’ imagined dominant within such time‐spaces. In this paper we explore this by describing attitudes towards, and reactions to, one particularly contentious site: the ‘lap dance’ club. Often targeted by campaigners in England and Wales as a source of criminality and anti‐sociality, in this paper we shift the focus from fear to disgust, and argue that Sexual Entertainment Venues (SEVs) are opposed on the basis of moral judgments that reflect distinctions of both class and gender. Drawing on documentary analysis, survey results and interview data collected during guided walks, we detail the concerns voiced by those anxious about the presence of lap dance or striptease clubs in their town or city, particularly the notion that they ‘lower the tone’ of particular streets or neighbourhoods. Our conclusion is that the opposition expressed to lap dance clubs is part of an attempt to police the boundaries of respectable masculinities and femininities, marginalizing the producers and consumers of sexual entertainment through ‘speech acts’ which identify such entertainment as unruly, vulgar and uncivilized. These findings are considered in the light of ongoing debates concerning the relations of morality, respectability and disgust. PMID:27708460

  10. Development of a novel ex vivo porcine laparoscopic Heller myotomy and Nissen fundoplication training model (Toronto lap-Nissen simulator).

    Science.gov (United States)

    Ujiie, Hideki; Kato, Tatsuya; Hu, Hsin-Pei; Bauer, Patrycja; Patel, Priya; Wada, Hironobu; Lee, Daiyoon; Fujino, Kosuke; Schieman, Colin; Pierre, Andrew; Waddell, Thomas K; Keshavjee, Shaf; Darling, Gail E; Yasufuku, Kazuhiro

    2017-06-01

    Surgical trainees are required to develop competency in a variety of laparoscopic operations. Developing laparoscopic technical skills can be difficult as there has been a decrease in the number of procedures performed. This study aims to develop an inexpensive and anatomically relevant model for training in laparoscopic foregut procedures. An ex vivo , anatomic model of the human upper abdomen was developed using intact porcine esophagus, stomach, diaphragm and spleen. The Toronto lap-Nissen simulator was contained in a laparoscopic box-trainer and included an arch system to simulate the normal radial shape and tension of the diaphragm. We integrated the use of this training model as a part of our laparoscopic skills laboratory-training curriculum. Afterwards, we surveyed trainees to evaluate the observed benefit of the learning session. Twenty-five trainees and five faculty members completed a survey regarding the use of this model. Among the trainees, only 4 (16%) had experience with laparoscopic Heller myotomy and Nissen fundoplication. They reported that practicing with the model was a valuable use of their limited time, repeating the exercise would be of additional benefit, and that the exercise improved their ability to perform or assist in an actual case in the operating room. Significant improvements were found in the following subjective measures comparing pre- vs. post-training: (I) knowledge level (5.6 vs. 8.0, Pmyotomy and fundoplication.

  11. I = 2 ππ scattering phase shift from the HAL QCD method with the LapH smearing

    Science.gov (United States)

    Kawai, Daisuke; Aoki, Sinya; Doi, Takumi; Ikeda, Yoichi; Inoue, Takashi; Iritani, Takumi; Ishii, Noriyoshi; Miyamoto, Takaya; Nemura, Hidekatsu; Sasaki, Kenji

    2018-04-01

    Physical observables, such as the scattering phase shifts and binding energy, calculated from the non-local HAL QCD potential do not depend on the sink operators used to define the potential. In practical applications, the derivative expansion of the non-local potential is employed, so that physical observables may receive some scheme dependence at a given order of the expansion. In this paper, we compare the I=2ππ scattering phase shifts obtained in the point-sink scheme (the standard scheme in the HAL QCD method) and the smeared-sink scheme (the LapH smearing newly introduced in the HAL QCD method). Although potentials in different schemes have different forms as expected, we find that, for reasonably small smearing size, the resultant scattering phase shifts agree with each other if the next-to-leading-order (NLO) term is taken into account. We also find that the HAL QCD potential in the point-sink scheme has a negligible NLO term for a wide range of energies, which implies good convergence of the derivative expansion, while the potential in the smeared-sink scheme has a non-negligible NLO contribution. The implications of this observation for future studies of resonance channels (such as the I=0 and 1ππ scatterings) with smeared all-to-all propagators are briefly discussed.

  12. Mechanics of Suture Joints

    Science.gov (United States)

    Li, Yaning; Song, Juha; Ortiz, Christine; Boyce, Mary; Ortiz Group/DMSE/MIT Team; Boyce Group/ME/MIT Team

    2011-03-01

    Biological sutures are joints which connect two stiff skeletal or skeletal-like components. These joints possess a wavy geometry with a thin organic layer providing adhesion. Examples of biological sutures include mammalian skulls, the pelvic assembly of the armored fish Gasterosteus aculeatus (the three-spined stickleback), and the suture joints in the shell of the red-eared slider turtle. Biological sutures allow for movement and compliance, control stress concentrations, transmit loads, reduce fatigue stress and absorb energy. In this investigation, the mechanics of the role of suture geometry in providing a naturally optimized joint is explored. In particular, analytical and numerical micromechanical models of the suture joint are constructed. The anisotropic mechanical stiffness and strength are studied as a function of suture wavelength, amplitude and the material properties of the skeletal and organic components, revealing key insights into the optimized nature of these ubiquitous natural joints.

  13. Expansion joints for LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Dzenus, M.; Hundhausen, W.; Jansing, W.

    1979-10-15

    This discourse recounts efforts put into the SNR-2 project; specifically the development of compensation devices. The various prototypes of these compensation devices are described and the state of development reviewed. The expansion joints were developed on the basis of specific design criteria whereby differentiation is made between expansion joints of small and large nominal diameter. Expansion joints for installation in the sodium-filled primary piping are equipped with safety bellows in addition to the actual working bellows.

  14. The Effect of Welding Energy on the Microstructural and Mechanical Properties of Ultrasonic-Welded Copper Joints

    Science.gov (United States)

    Yang, Jingwei; Cao, Biao; Lu, Qinghua

    2017-01-01

    The effects of welding energy on the mechanical and microstructural characteristics of ultrasonic-welded pure copper plates were investigated. Complex dynamic recrystallization and grain growth occurred inside the weld zone during ultrasonic welding. At a low welding energy, a thin band of straight weld interfaces was observed and had an ultra-fine grain structure. With an increase in welding energy, the weld interface progressively changed from flat to sinusoidal, and eventually turned into a convoluted wavy pattern, bearing similarities to shear instabilities, as observed in fluid dynamics. The lap shear load of the joints initially increased and then remained stable as the welding energy increased. The tensile characteristics of the joints significantly depended on the development of plastic deformation at the interface. The influence of the microstructure on the hardness was also discussed. PMID:28772553

  15. A Fracture-Based Criterion for Debonding Strength of Adhesive-Bonded Double-Strap Steel Joints

    Directory of Open Access Journals (Sweden)

    Prawit Santisukpotha

    2012-01-01

    Full Text Available This paper addresses the debonding strength of adhesive-bonded double-strap steel joints. A fracture-based criterion was formulated in terms of a stress singularity parameter, i.e., the stress intensity factor, which governs the magnitude of a singular stress field near the joint ends. No existing crack was assumed. A total of 24 steel joint specimens were tested under constant amplitude fatigue loadings at stress ratio of 0.2 and frequency of 2 Hz. The joint stiffness ratio was slightly less than one to control the maximum adhesive stresses at the joint ends. To detect the debonding, a simple and practical technique was developed. The test results showed that the interfacial failure near the steel/adhesive corner was a dominant failure mode. The failure was brittle and the debonding life was governed by the crack initiation stage. The finite element analysis was employed to calculate the stress intensity factors and investigate the effects of the adhesive layer thickness, lap length and joint stiffness ratio on the debonding strength.

  16. JET Joint Undertaking

    International Nuclear Information System (INIS)

    Keen, B.E.

    1987-03-01

    The paper presents the progress report of the Joint European Torus (JET) Joint Undertaking, 1986. The report contains a survey of the scientific and technical achievements on JET during 1986; the more important articles referred to in this survey are reproduced as appendices to this Report. The last section discusses developments which might improve the overall performance of the machine. (U.K.)

  17. 13. Sacroiliac joint pain

    NARCIS (Netherlands)

    Vanelderen, P.; Szadek, K.M.; Cohen, S.P.; Witte, J.; Lataster, A.; Patijn, J.; Mekhail, N.; van Kleef, M.; van Zundert, J.

    2010-01-01

    The sacroiliac joint accounts for approximately 16% to 30% of cases of chronic mechanical low back pain. Pain originating in the sacroiliac joint is predominantly perceived in the gluteal region, although pain is often referred into the lower and upper lumbar region, groin, abdomen, and/ or lower

  18. Joint Newspaper Operating Agreements.

    Science.gov (United States)

    Parsons, Marie

    The number of competing daily newspapers in American cities has dwindled until only about 50 cities boast two papers. Of the newspapers in those cities, 23 now maintain separate editorial operations but have joint printing, advertising, and circulation departments. The concept of joint operation is 50 years old, dating from the Depression years…

  19. Joint Hub Network Development

    NARCIS (Netherlands)

    Cruijssen, F.C.A.M.; Borm, P.E.M.; Dullaert, W.; Hamers, H.J.M.

    2007-01-01

    This paper introduces a framework for joint hub network development. Building a joint physical hub for transhipment of goods is expensive and therefore involves considerable risks for the cooperating companies. In a practical setting, it is unlikely that an entire network will be built at once.

  20. Elbow joint instability

    DEFF Research Database (Denmark)

    Olsen, Bo Sanderhoff; Henriksen, M G; Søjbjerg, Jens Ole

    1994-01-01

    The effect of simultaneous ulnar and radial collateral ligament division on the kinematics of the elbow joint is studied in a cadaveric model. Severance of the anterior part of the ulnar collateral ligament and the annular ligament led to significant elbow joint instability in valgus and varus...

  1. Bistable Articulated Joint

    Science.gov (United States)

    Graighead, Norwood D., II; Preliasco, R. J.; Hult, T. D.

    1986-01-01

    Joint with four-bar-linkage geometry has following attributes: Springs to fully extended fully folded positions. Automatically locks in its extended position. Joint combines zero backlash, positive locking, and centerline pivoting. Used in folding tool handles, portable antenna booms, and many other deployable structures.

  2. MP Joint Arthritis

    Science.gov (United States)

    ... All Topics A-Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is a Hand Surgeon? What is a Hand Therapist? Media Find a Hand Surgeon Home Anatomy MP Joint Arthritis Email to a friend * required ...

  3. Creep of timber joints

    NARCIS (Netherlands)

    Van de Kuilen, J.W.G.

    2008-01-01

    A creep analysis has been performed on nailed, toothed-plates and split-ring joints in a varying uncontrolled climate. The load levels varied between 30% and 50% of the average ultimate short term strength of these joints, tested in accordance with ISO 6891. The climate in which the tests were

  4. The Role of Mechanical Connection during Friction Stir Keyholeless Spot Welding Joints of Dissimilar Materials

    Directory of Open Access Journals (Sweden)

    Xiao Liu

    2017-06-01

    Full Text Available Contrast experiments of lap joints among dissimilar AZ31B Mg alloy, Mg99.50, zinc-coated DP600 sheet, and non-zinc-coated DP600 sheet were made by friction stir keyholeless spot welding (FSKSW and vacuum diffusion welding (VDW, respectively. Scanning electron microscopy (SEM and energy disperse spectroscopy (EDS were used to investigate the microstructures and components of the joints welded. The experimental results show that the FSKSW bonding method is a kind of compound mode that contains a mechanical connection and element diffusion fusion connection, in which mechanical connection has the main decisive function on joints of Mg/steel. Elements diffusion exists in the interfacial region of the joints and the elements diffusion extent is basically the same to that of VDW. The elements’ diffusion in Mg/steel using FSKSW is defined in the reaction between small amounts elements of the base metal and zinc-coated metals. The intermetallic compounds and composite oxide perform some reinforcement on the mechanical connection strength.

  5. MR diagnosis of temporomandibular joint. A study of joint effusion

    International Nuclear Information System (INIS)

    Kaneda, Takashi; Yamashiro, Mitsuaki; Ozawa, Kaoru; Suzuki, Hiromi; Okada, Hiroyuki; Yamamoto, Hirotsugu

    1998-01-01

    The purposes of this study were to evaluate the relationship between correlation of MR joint effusion of the temporomandibular joint and disk position, to evaluate the relationship between joint effusion and aging, and to assess the frequency of MR joint effusion of bilateral temporomandibular joints. The temporomandibular joints of 192 patients with clinical symptoms of temporomandibular joint disorders were imaged bilaterally using high field, surface-coil MR imaging. Oblique sagittal and coronal proton density-weighted and T2-weighted images were obtained. Imaging findings of joint effusion were correlated with disk position, aging, and bilateral temporomandibular joints. MR showed effusion in 4% of the joints with normal superior disk position, 36% of the joints with disk displacement with reduction, and 45% of the joints with disk displacement without reduction. There were significant differences in the incidence of joint effusion between normal disk position and anterior disk displacement with or without reduction. Younger patients less than 40 years were significant higher the incidence of joint effusion than those of older patients. A significant association was seen between joint effusion and aging. MR showed effusion in 17% of the unilateral temporomandibular joint, 24% of the bilateral temporomandibular joints. There was no significant difference between unilateral and bilateral case. These results indicated that joint effusion using MR imaging was associated with varied temporomandibular joint pathologic states. (author)

  6. Generalised joint hypermobility and knee joint hypermobility

    DEFF Research Database (Denmark)

    Junge, Tina; Henriksen, Peter; Hansen, Sebrina

    2018-01-01

    . Respondents with GJHk and KJH reported lower HRQoL. CONCLUSION: GJHk and KJH were frequently reported in the Danish adult population, mostly in women. Respondents with GJHk and KJH were two times more likely to report knee joint-related symptoms such as pain, reduced performance of usual activity and lower...

  7. Long-term, repeated dose in vitro neurotoxicity of the glutamate receptor antagonist L-AP3, demonstrated in rat hippocampal slice cultures by using continuous propidium iodide incubation.

    Science.gov (United States)

    Kristensen, Bjarne W; Blaabjerg, Morten; Noraberg, Jens; Zimmer, Jens

    2007-05-01

    Most in vitro models are only used to assess short-term effects of test compounds. However, as demonstrated here, hippocampal slice cultures can be used for long-term studies. The test compound used was the metabotropic glutamate receptor antagonist, L(+)-2-amino-3-phosphonopropionic acid (L-AP3), which is known to be toxic in vivo after subchronic, but not acute, administration. Degenerative effects were monitored by measuring the cellular uptake of propidium iodide (PI; continuously present in the medium) and lactate dehydrogenase (LDH) leakage, and by using a panel of histological stains. Hippocampal slices, derived from 2-3 day old rats and grown for 3 weeks, were subsequently exposed for the next 3 weeks to 0, 10 or 100microM L-AP3, with PI (2microM) in the culture medium. Exposure to 100microM L-AP3 induced severe toxicity after 4-6 days, shown by massive PI uptake, LDH leakage, changes in MAP2 and GFAP immunostaining, and in Nissl and Timm staining. In contrast, 10microM L-AP3 did not induce detectable neuronal degeneration. Treatment with the NMDA receptor antagonist, MK-801, or the AMPA/KA receptor antagonist NBQX, together with 100microM L-AP3, reduced neurodegeneration down to close to control values. It is concluded that continuous incubation of hippocampal slice cultures with PI is technically feasible for use in studies of inducible neuronal degeneration over time.

  8. Lap-belt syndrome: management of aortic intimal dissection in a 7-year-old child with a constellation of injuries

    International Nuclear Information System (INIS)

    Khanna, Paritosh C.; Bulas, Dorothy I.; Rothenbach, Patricia; Guzzetta, Philip C.

    2007-01-01

    We present a case of lap-belt motor vehicle injury in a 7-year-old male who was admitted with abdominal ecchymoses and pain with associated aortic intimal flap, bowel injury, hemoperitoneum, and retroperitoneal hematoma at initial imaging with CT. Most of these findings were confirmed at subsequent laparotomy, and the patient underwent operative repair of bowel injuries. His aortic intimal flap was followed with US and color Doppler imaging during which time he was treated conservatively until there was sonographic evidence of intimal healing. This patient illustrates a multimodality approach to imaging and conservative management. (orig.)

  9. Joint Electromagnetic Spectrum Management Operations

    Science.gov (United States)

    2012-03-20

    promulgate command-specific policy and guidance for EMS use, the joint restricted frequency list (JRFL) process, the joint communications–electronics...joint communications–electronics operating instructions (JCEOI) and joint restricted frequency list (JRFL). Examples of FM include providing the...joint restricted frequency list Figure III-4. Joint Frequency Management Office Spectrum Management Process Chapter III III-10 JP 6-01 assignments

  10. LAP-BAND for BMI 30-40: 5-year health outcomes from the multicenter pivotal study.

    Science.gov (United States)

    Dixon, J B; Eaton, L L; Vincent, V; Michaelson, R

    2016-02-01

    We performed a 5-year multicenter study to evaluate the safety and effectiveness of the LAP-BAND System surgery (LBS) in patients with obesity with a body mass index (BMI) of 30-39.9 kg m(-)(2). This pivotal study was designed to support LBS application to the US Food and Drug Administration for broadening the indications for surgery and the lower BMI indication was approved with 1-year data in 2011, with the intention to complete the 5-year evaluation. To present broad health outcome data including weight change, patient reported outcomes, comorbidity change and complications during the 5-year study. The study was conducted at seven US private practice clinical trial sites. We enrolled 149 BMI 30-39.9 subjects into a 5-year, multicenter, longitudinal, prospective post-approval study. Data for those completing each time point are presented. The predefined target of at least 30% excess weight loss was achieved by more than 76% of subjects by 1-year and at every year thereafter during the 5-year study. Mean percentage weight loss at 5 years was 15.9±12.4%. Sustained weight loss was accompanied by sustained improvement in generic and weight-specific quality of life, symptoms of depression and the prevalence of binge-eating disorder. The number of subjects with normal fasting triglyceride, high-density lipoprotein cholesterol, plasma glucose and HbA1c increased significantly between baseline and 5 years. Fifty-four months after LBS implantation, the rate of device explants without replacement was 5.4%; however, the rate of explants increased to 12.1% by month 60 owing to no cost-elective band removals offered to subjects at study exit. No deaths or unanticipated adverse device effects were reported. The LBS is safe and effective for people with BMI 30-39.9 with demonstrated improvements in weight loss, comorbidities and quality of life, and with a low explant rate through 5 years following treatment.

  11. Joint Quantum Institute

    Data.gov (United States)

    Federal Laboratory Consortium — The Joint Quantum Institute (JQI) is pursuing that goal through the work of leading quantum scientists from the Department of Physics of the University of Maryland...

  12. Temporomandibular Joint Disorder

    Science.gov (United States)

    ... Baby Bottle Tooth Decay? Pacifiers Have Negative and Positive Effects What is Dental Amalgam (Silver Filling)? Check Menstrual Calendar for Tooth Extraction Temporomandibular Joint Disorder Learn what those dental words mean. Check out how your teeth and mouth ...

  13. Hip joint replacement

    Science.gov (United States)

    Hip arthroplasty; Total hip replacement; Hip hemiarthroplasty; Arthritis - hip replacement; Osteoarthritis - hip replacement ... Your hip joint is made up of 2 major parts. One or both parts may be replaced during surgery: ...

  14. Knee joint replacement

    Science.gov (United States)

    ... to make everyday tasks easier. Practice using a cane, walker , crutches , or a wheelchair correctly. On the ... ask your doctor Knee joint replacement - discharge Preventing falls Preventing falls - what to ask your doctor Surgical ...

  15. Concrete pavement joint deterioration.

    Science.gov (United States)

    2015-12-01

    Concrete pavements are an important part of our national infrastructure. In recent years the relatively small number of reported joints deteriorating prematurely in concrete pavements around Indiana has increased. Changes over the past 45 years in IN...

  16. Sacroiliac joint dysfunction.

    Science.gov (United States)

    Ilaslan, Hakan; Arslan, Ahmet; Koç, Omer Nadir; Dalkiliç, Turker; Naderi, Sait

    2010-07-01

    Sacroiliac joint dysfunction is a disorder presenting with low back and groin pain. It should be taken into consideration during the preoperative differential diagnosis of lumbar disc herniation, lumbar spinal stenosis and facet syndrome. Four cases with sacroiliac dysfunction are presented. The clinical and radiological signs supported the evidence of sacroiliac dysfunction, and exact diagnosis was made after positive response to sacroiliac joint block. A percutaneous sacroiliac fixation provided pain relief in all cases. The mean VAS scores reduced from 8.2 to 2.2. It is concluded that sacroiliac joint dysfunction diagnosis requires a careful physical examination of the sacroiliac joints in all cases with low back and groin pain. The diagnosis is made based on positive response to the sacroiliac block. Sacroiliac fixation was found to be effective in carefully selected cases.

  17. Erivajadustega laps / Inga Mutso

    Index Scriptorium Estoniae

    Mutso, Inga, 1959-

    2002-01-01

    Sept. 2000 - märts 2001 viidi Tartu Õppekeskuse, TPÜ täiendkoolituse osakonna ja Geomeedia Erakooli eripedagoogikaalastel täiendusõppe kursustel osalenud pedagoogide seas läbi ankeetküsitlus. Uuringus selgus, et erivajadustega õpilaste integreerimist tavakooli takistab vajaliku väljaõppe saanud pedagoogide puudumine ja koolide mittevalmisolek

  18. Joint Hub Network Development

    OpenAIRE

    Cruijssen, F.C.A.M.; Borm, P.E.M.; Dullaert, W.; Hamers, H.J.M.

    2007-01-01

    This paper introduces a framework for joint hub network development. Building a joint physical hub for transhipment of goods is expensive and therefore involves considerable risks for the cooperating companies. In a practical setting, it is unlikely that an entire network will be built at once. Rather, the partners will have a more cautious attitude and build the hub facilities one-by-one. In the proposed framework, every time a new hub is introduced, partners will have the opportunity to dec...

  19. Prosthetic Joint Infections

    Science.gov (United States)

    Aslam, Saima; Darouiche, Rabih O.

    2012-01-01

    Prosthetic joint infections represent a major therapeutic challenge for both healthcare providers and patients. This paper reviews the predisposing factors, pathogenesis, microbiology, diagnosis, treatment and prophylaxis of prosthetic joint infection. The most optimal management strategy should be identified based on a number of considerations including type and duration of infection, antimicrobial susceptibility of the infecting pathogen, condition of infected tissues and bone stock, patient wishes and functional status. PMID:22847032

  20. Benign joint hypermobility syndrome

    Directory of Open Access Journals (Sweden)

    Iwona Słowińska

    2014-11-01

    Full Text Available Benign joint hypermobility syndrome (BJHS, commonly known as loose ligament syndrome, is a non-inflammatory rheumatic condition. It is characterised by a greater than normal range of motion of the joints of the limbs and spine. The prevalence of the syndrome in preschool-age children is estimated to be between 2% and 30%, depending on ethnic background (with higher prevalence in Asian and African populations, occurring most often in families with a history of the condition and more frequently in girls. This paper presents a case report of a 12-year-old girl. A broad differential diagnostic approach to recurrent joint inflammation with joint effusion and pain made it possible to establish a diagnosis of benign joint hypermobility syndrome. The child met the Brighton criteria; her Beighton score was 7 out of 9. Patient education aimed at eliminating abnormal joint movement and an appropriate rehabilitation programme play key roles in the treatment of BJHS.

  1. Comparative Analysis of Welded and Adhesive Joints Strength Made of Acid-Resistant Stainless Steel Sheets

    Directory of Open Access Journals (Sweden)

    Izabela Miturska

    2017-12-01

    Full Text Available The article presents the selected results of strength tests on the effectiveness of bonding high-alloy steel 1.4310. Sheet steel is one of the materials that are difficult to activate energy. Effective joining of it is difficult, requires selection of the appropriate bonding technology. The paper focuses on the comparative tests the shear strength of one-single lap welded and bonded joints. The welding process was performed 3 groups of samples TIG welding and argon, where the variable value of the welding process was current: 60A, 70A, 80A. The adhesion process was performed in 6 groups of samples which differed in the method of surface preparation and the type of the adhesive. Adhesive joints were made by using adhesive of epoxy resin and a hardener: Epidian 61/TFF at a mass ratio of 100:22 and Epidian 61/IDA at a mass ratio of 100:40. As a way of surface preparation applied 3 different, but simplified and environmentally friendly methods of surface preparation: degreasing with using cleaner Loctite 7061, abrasive machining with P320 and degreasing and grinding with abrasive T800 and degreasing were used. Make joints and curing the adhesive joints were carried out at ambient temperature. Analyzed the joints were tested destructive - which set out the shear strength, in accordance with DIN EN 1465 on the testing machine Zwick / Roell Z150. Based on the results of research it was found that better results were obtained for the maximum welded joints, but this result was similar to the maximum value of the strength of the adhesive bond.

  2. Laparoscopic subtotal hysterectomy using the plasma kinetic and lap loop systems: an alternative approach in the surgical management of women with uterine fibroids.

    Science.gov (United States)

    Erian, John; El-Shawarby, Salem A; Hassan, Mohsen; Wissa, Ihab; Chandakas, Stefanos; Hill, Nicholas

    2008-03-01

    To evaluate the safety and applicability of laparoscopic subtotal hysterectomy (LSH) using the plasma kinetic (PK) and lap loop systems as an alternative surgical approach in the management of uterine fibroids in women who have completed their families. Sixty-two consecutive LSH were performed during this prospective study from March 2003 to March 2005 at Princess Royal University Hospital, Kent, UK. All study patients had menorrhagia resistant to at least one form of therapy, with a mean duration of symptoms of 3.5 years. In addition, four patients had previous myomectomy. The mean number of fibroids removed was 2.7. The mean weight of the uterus was 141.9 g. The mean operative time was 46.8 min, and the mean blood loss was 126.6 mL. The overall perioperative complication rate was 4.8% with no visceral injury, or return to theatre. At follow-up, all patients were satisfied with surgery. The study describes the first application of the PK and Lap Loop systems in LSH for the surgical management of uterine fibroids in women in whom fertility is not an issue, and its findings suggest that this minimally invasive technique is a safe, and valid alternative. Larger adequately-powered studies are however still required.

  3. Jointness for the Rest of Us: Reforming Joint Professional Development

    Science.gov (United States)

    2016-06-10

    transferred to the Joint Staff. 13 DOD’s instinct to “overly centralize planning, organization, and management.”20 The authors contend that this...2. 3 John F. Schank and others, Who is Joint? Reevaluating the Joint Duty Assignment List : A Study Prepared for the Joint Staff, by the RAND...and code those billets as such. Once identified, DOD must expand the Joint Duty Assignment List (JDAL) to include billets that offer enlisted personnel

  4. Application of Box–Behnken design for fabrication of titanium alloy and 304 stainless steel joints with silver interlayer by diffusion bonding

    International Nuclear Information System (INIS)

    Balasubramanian, M.

    2015-01-01

    Highlights: • Diffusion bonding of Ti–6Al–4V to SS304 with silver interlayer was successful. • Hardness and shear strength increased with the increase in the bonding temperature. • Shear strength of 149 MPa and 18% strain to failure were achieved. • Joint efficiency of 80% was obtained for the Ti–6Al–4V and SS304L joints. - Abstract: Direct bonding between titanium (Ti)/titanium alloy(Ti alloy) and stainless steel (SS) promotes the formation of various Fe–Ti and Fe–Cr–Ti intermetallics in the diffusion zone, because the solid solubility of Fe, Cr, Ni and Ti in each other is limited and these intermetallics weaken the mechanical properties of the joint. The present study focuses on the titanium alloy Ti–6Al–4V diffusion bonded to AISI 304 stainless steel with silver foil as an interlayer. The process parameters were chosen appropriately and hence, the bonding is achieved without any defect. Box–Behnken design is used to decide the optimum number of experiments required to do the investigation. Microhardness measurements and the lap shear test were carried out to determine the hardness and strength of the joints respectively. The results show that atomic diffusion and migration between Ti and Fe or C are effectively prevented by adding pure Ag as the interlayer metal. The results from mechanical testing showed that shear strength values have a direct relationship with bonding time. The maximum lap shear strength of 149 MPa and 18% strain to failure was observed for joints obtained with bonding time of 60 min. However, effective bonding was not possible at 850 °C due to incomplete coalescence of mating surfaces

  5. Acromioclavicular joint separation

    Directory of Open Access Journals (Sweden)

    Devan Pandya, BS

    2018-04-01

    Full Text Available History of present illness: A 30-year-old male was brought in by ambulance to the emergency department as a trauma activation after a motorcycle accident. The patient was the helmeted rider of a motorcycle traveling at an unknown speed when he lost control and was thrown off his vehicle. He denied loss of consciousness, nausea, or vomiting. The patient’s vital signs were stable and his only complaint was pain around his left shoulder. On exam, the patient had a prominent left clavicle without skin compromise. He had adequate range of motion in the left shoulder with moderate pain, and his left upper extremity was neurovascularly intact. Significant findings: Plain films of the left shoulder showed elevation of the left clavicle above the acromion. There was an increase in the acromioclavicular (AC and coracoclavicular (CC distances (increased joint distances marked with red and blue arrows, respectively. A normal AC joint measures 1-3 mm whereas a normal CC distance measures 11-13 mm.1 The injury was classified as a Rockwood type III AC joint separation. Discussion: The AC joint is a synovial joint between an oval facet on the acromion and a similar facet on the distal end of the clavicle. Horizontal stability is provided by the AC joint while axial stability is provided by the CC joint.2,3 AC joint injuries account for about 9%-12% of shoulder girdle injuries, and the most common mechanism is direct trauma.4,5 Initial evaluation with imaging includes plain films with three views: the anterior-posterior (AP view with the shoulder in internal and external rotation as well as an axillary, or scapula-Y view (sensitivity 40%, specificity 90% for all films.6,7 AC joint injuries are classified by the Rockwood system.8 Type I involves a sprain or incomplete tear of the AC ligaments with an intact CC ligament. The AC joint appears normal on X-ray, but can become widened with stress, achieved by having the patient hold a 10-15 pound weight from each

  6. Microstructure and Mechanical Properties of Ultrasonic Spot Welded Mg/Al Alloy Dissimilar Joints

    Directory of Open Access Journals (Sweden)

    He Peng

    2018-04-01

    Full Text Available Lightweight structural applications of magnesium and aluminum alloys inevitably necessitate welding and joining, especially dissimilar welding between these alloys. The objective of this study was to examine the feasibility of joining ZEK100 Mg alloy to Al6022 alloy via ultrasonic spot welding, focusing on effects of welding energy. An interface diffusion layer consisting of α-Mg and Al12Mg17 eutectic structure was observed to form, with its thickness increased from ~0.5 µm to ~30 µm with increasing welding energy from 500 J to 2000 J. The tensile lap shear peak load or strength and critical stress intensity of the welded joints first increased and then decreased with increasing welding energy, with their peak values achieved at 750 J. Fatigue life of the joints made at 750 J and 2000 J was equivalent at the lower cyclic loading levels, while it was longer for the joints made at 750 J at the higher cyclic loading levels. Fatigue fracture mode changed from interfacial failure to mainly transverse-through-thickness crack growth with decreasing cyclic loading level, which corresponded well to the bi-linear characteristic of S-N curves. Crack initiation basically occurred at the weld nugget border and at the interface between the two sheets, which can be understood via a theoretical stress analysis.

  7. Forming a multinational joint venture

    International Nuclear Information System (INIS)

    Bhatia, N.K.; Garb, R.H.; Statton, T.D.

    1990-01-01

    This paper discusses the basis and mechanics for forming a multinational joint venture. The topics of the paper include the motivations for a joint venture, selection of the appropriate co-venturer, management of the multinational joint venture, and the joint venture agreement. The authors state that a joint venture is not applicable or desirable in all instances and to be successful, must be carefully planned

  8. Facet joint syndrome

    International Nuclear Information System (INIS)

    Zigrai, M.; Zakovic, J.; Brezinova, M.; Pavlovicova, M.

    2002-01-01

    It is the purpose of the study to demonstrate the clinical relevance of degenerative changes in the facet joint of patients with low back pain irradiating to the lower extremities, and discuss some problems relating to diagnosis and different diagnosis. 119 patients presenting the listed bellow syndromes are covered by the study: scoliosis, polytopic pain vertebral syndrome, paresis and history of trauma. all patients undergo comprehensive neurological examination with special attention focused on the spine: CT and plain x-rays are taken of the lumbosacral segment to assess the condition of the facet joints. The neurological examination demonstrates in all cases pain syndrome in the lumbar spine referred to one or both lower extremities. In 56% it is a matter of persisting pain, and in 44% - recurrent. More than half of the patients complain of sacroiliac (SI) dislocation and palpatory pain. Unilateral or bilateral degenerative changes are documented by imaging studies in all patients, including: subchondral thickening, osteopathy narrowing the lateral or central part of the spinal canal with ensuing nerve root compression. The lumbosacral zygoapophyseal joints are source of pseudoradicular pain. A correlation between clinical picture and GT changes is noted in all patients with facet joint syndrome. CT is an indispensable method in diagnosing facet joint syndrome. (authors)

  9. Temporomandibular joint examination reviewed

    Directory of Open Access Journals (Sweden)

    L. Guarda Nardini

    2011-09-01

    Full Text Available The temporo-mandibular joint (TMJ it’s a joint closely related to the skull base, the spine, and the jaws; all these anatomical structures must be taken in consideration when evaluating pain involving the tmj. In order to detect patients affected by pathology or dysfunctions of the tmj, physical examination is of great value in orienting the diagnosis. Inspection must consider the symmetry of the body, the dental status and the type of occlusion. Palpation is a way to assess contractiont involving the muscles of the masticatory system and of the neck. Auscultation, based on articular noise provides means to determine whether we are dealing with degeneration of the joint or a dislocation of the intrarticular disc. In order to confirm the diagnosis obtained with the clinical evaluation, it’s useful to perform imaging techniques as opt, tomography and TC of the tmj and electromyokineosiography – index of the mandibular functionality and of the muscles status. MRI and dynamic MRI are among the non invasive exams which give the greatest amount of information, regarding the disc position and the joint degeneration. Arthroscopy is an invasive technique that allows early diagnosis of degeneration and is helpful to reveal early inflammatory processes of the joint.

  10. Distal radioulnar joint injuries

    Directory of Open Access Journals (Sweden)

    Binu P Thomas

    2012-01-01

    Full Text Available Distal radioulnar joint is a trochoid joint relatively new in evolution. Along with proximal radioulnar joint , forearm bones and interosseous membrane, it allows pronosupination and load transmission across the wrist. Injuries around distal radioulnar joint are not uncommon, and are usually associated with distal radius fractures,fractures of the ulnar styloid and with the eponymous Galeazzi or Essex_Lopresti fractures. The injury can be purely involving the soft tissue especially the triangular fibrocartilage or the radioulnar ligaments.The patients usually present with ulnar sided wrist pain, features of instability, or restriction of rotation. Difficulty in carrying loads in the hand is a major constraint for these patients. Thorough clinical examination to localize point of tenderness and appropriate provocative tests help in diagnosis. Radiology and MRI are extremely useful, while arthroscopy is the gold standard for evaluation. The treatment protocols are continuously evolving and range from conservative, arthroscopic to open surgical methods. Isolated dislocation are uncommon. Basal fractures of the ulnar styloid tend to make the joint unstable and may require operative intervention. Chronic instability requires reconstruction of the stabilizing ligaments to avoid onset of arthritis. Prosthetic replacement in arthritis is gaining acceptance in the management of arthritis.

  11. Formation of Exfoliation Joints

    Science.gov (United States)

    Martel, S. J.

    2004-12-01

    The Earth's internal stresses interact with the topographic surface to affect many phenomena. Exfoliation joints, or sheeting joints, are widespread manifestations of this interaction. These opening-mode fractures form subparallel to the Earth's surface, bounding roughly concentric slabs of rock that resemble the layers of an onion. They occur worldwide in all major bedrock types, attain in-plane dimensions of hundreds of meters, exert a strong influence on groundwater flow, and help produce spectacular scenery, as in Yosemite National Park. The mechanism that causes them has been enigmatic. They are widely regarded as forming in response to "removal of overburden", but large fractures do not open in rocks merely by relieving a compressive stress. High fluid pressures, thermal effects, rock heterogeneity, and weathering also are rejected as primary causes of these fractures. Tensile stresses normal to the surface are required for large exfoliation fractures to open. Intriguingly, high surface-parallel compressive stresses are widely documented where exfoliation joints occur. Both numerical and analytical solutions for two-dimensional elastic bodies show that localized tensile stresses perpendicular to the ground surface must develop beneath certain topographies subject to strong compressive stresses parallel to the surface. This highly non-intuitive effect reflects the profound influence that topography can have on stresses near the surface of the Earth, and it can explain how exfoliation joints open. The theoretical results also indicate that exfoliation joint distributions could be used to infer the horizontal stresses near the Earth's surface.

  12. The temporomandibular joint

    International Nuclear Information System (INIS)

    Campbell, W.

    1984-01-01

    Whilst the temporomandibular joint is in many ways unique, it is subject to all the diseases and disorders found in joints in other parts of the human skeleton. By far the most common disorder is injury, followed by arthropathy, acute and chronic dislocations, ankylosis, and in rare instances, neoplasms. The diagnosis and management of the temporomandibular joint are the primary responsibility of the oral surgeon. Nevertheless, this anatomical region is an area in which the cooperation of medical and dental disciplines may be required for the satisfactory conclusion of treatment. The more so when the disease process involves either associated psychosomatic illness or malignancy. The mainstay of the diagnosis is a careful radiological examination of the joint. There exists a delicate relationship between the dentition, the muscles of mastication, and the temporomandibular articulation, which is controlled by arthrokinetic reflex activity of the branches of the 5th cranial nerve. Imbalance between one or more of the components of this integrated system frequently leads to disturbances in function. Pain-dysfunction disorders constitute the larger part of temporomandibular joint disturbances generally encountered

  13. Total ankle joint replacement.

    Science.gov (United States)

    2016-02-01

    Ankle arthritis results in a stiff and painful ankle and can be a major cause of disability. For people with end-stage ankle arthritis, arthrodesis (ankle fusion) is effective at reducing pain in the shorter term, but results in a fixed joint, and over time the loss of mobility places stress on other joints in the foot that may lead to arthritis, pain and dysfunction. Another option is to perform a total ankle joint replacement, with the aim of giving the patient a mobile and pain-free ankle. In this article we review the efficacy of this procedure, including how it compares to ankle arthrodesis, and consider the indications and complications. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  14. Friction stir welding joint of dissimilar materials between AZ31B magnesium and 6061 aluminum alloys: Microstructure studies and mechanical characterizations

    Energy Technology Data Exchange (ETDEWEB)

    Mohammadi, J. [Department of Materials Science and Engineering, Science and Research Branch, Islamic Azad University, Tehran 141554933 (Iran, Islamic Republic of); Behnamian, Y. [Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2V4 (Canada); Mostafaei, A., E-mail: amir.mostafaei@gmail.com [Young Researchers and Elites Club, Tehran North Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Izadi, H. [Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2V4 (Canada); Saeid, T. [Faculty of Materials Engineering, Sahand University of Technology, Tabriz 513351996 (Iran, Islamic Republic of); Kokabi, A.H. [Department of Materials Science and Engineering, Sharif University of Technology, Tehran 113659466 (Iran, Islamic Republic of); Gerlich, A.P., E-mail: adrian.gerlich@uwaterloo.ca [Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

    2015-03-15

    Friction stir welding is an efficient manufacturing method for joining dissimilar alloys, which can dramatically reduce grain sizes and offer high mechanical joint efficiency. Lap FSW joints between dissimilar AZ31B and Al 6061 alloy sheets were made at various tool rotation and travel speeds. Rotation and travel speeds varied between 560–1400 r/min and 16–40 mm/min respectively, where the ratio between these parameters was such that nearly constant pitch distances were applied during welding. X-ray diffraction pattern (XRD), optical microscopy images (OM), electron probe microanalysis (EPMA) and scanning electron microscopy equipped with an energy-dispersive X-ray spectroscopy (SEM-EDS) were used to investigate the microstructures of the joints welded. Intermetallic phases including Al{sub 12}Mg{sub 17} (γ) and Al{sub 3}Mg{sub 2} (β) were detected in the weld zone (WZ). For different tool rotation speeds, the morphology of the microstructure in the stir zone changed significantly with travel speed. Lap shear tensile test results indicated that by simultaneously increasing the tool rotation and travel speeds to 1400 r/min and 40 mm/min, the joint tensile strength and ductility reached a maximum. Microhardness measurements and tensile stress–strain curves indicated that mechanical properties were affected by FSW parameters and mainly depended on the formation of intermetallic compounds in the weld zone. In addition, a debonding failure mode in the Al/Mg dissimilar weld nugget was investigated by SEM and surface fracture studies indicated that the presence of intermetallic compounds in the weld zone controlled the failure mode. XRD analysis of the fracture surface indicated the presence of brittle intermetallic compounds including Al{sub 12}Mg{sub 17} (γ) and Al{sub 3}Mg{sub 2} (β). - Highlights: • Dissimilar Al/Mg joint was obtained by lap friction stir welding technique. • Effect of rotation and travel speeds on the formation of intermetallic

  15. Friction stir welding joint of dissimilar materials between AZ31B magnesium and 6061 aluminum alloys: Microstructure studies and mechanical characterizations

    International Nuclear Information System (INIS)

    Mohammadi, J.; Behnamian, Y.; Mostafaei, A.; Izadi, H.; Saeid, T.; Kokabi, A.H.; Gerlich, A.P.

    2015-01-01

    Friction stir welding is an efficient manufacturing method for joining dissimilar alloys, which can dramatically reduce grain sizes and offer high mechanical joint efficiency. Lap FSW joints between dissimilar AZ31B and Al 6061 alloy sheets were made at various tool rotation and travel speeds. Rotation and travel speeds varied between 560–1400 r/min and 16–40 mm/min respectively, where the ratio between these parameters was such that nearly constant pitch distances were applied during welding. X-ray diffraction pattern (XRD), optical microscopy images (OM), electron probe microanalysis (EPMA) and scanning electron microscopy equipped with an energy-dispersive X-ray spectroscopy (SEM-EDS) were used to investigate the microstructures of the joints welded. Intermetallic phases including Al 12 Mg 17 (γ) and Al 3 Mg 2 (β) were detected in the weld zone (WZ). For different tool rotation speeds, the morphology of the microstructure in the stir zone changed significantly with travel speed. Lap shear tensile test results indicated that by simultaneously increasing the tool rotation and travel speeds to 1400 r/min and 40 mm/min, the joint tensile strength and ductility reached a maximum. Microhardness measurements and tensile stress–strain curves indicated that mechanical properties were affected by FSW parameters and mainly depended on the formation of intermetallic compounds in the weld zone. In addition, a debonding failure mode in the Al/Mg dissimilar weld nugget was investigated by SEM and surface fracture studies indicated that the presence of intermetallic compounds in the weld zone controlled the failure mode. XRD analysis of the fracture surface indicated the presence of brittle intermetallic compounds including Al 12 Mg 17 (γ) and Al 3 Mg 2 (β). - Highlights: • Dissimilar Al/Mg joint was obtained by lap friction stir welding technique. • Effect of rotation and travel speeds on the formation of intermetallic compounds • Microstructure and chemical

  16. JOINT INVOLVEMENT IN SYPHILIS

    Directory of Open Access Journals (Sweden)

    T. I. Zlobina

    2016-01-01

    Full Text Available Joint involvement in syphilis has been considered as casuistry in recent years. At the same time, the high incidence of primary syphilis and the notified cases of late neurosyphilis may suggest that joint involvement in this disease is by no means always verified. Traditionally there are two forms of syphilitic arthritis: primary synovial (involving the articular membranes and sac and primary bone (involving the articular bones and cartilages ones. The paper describes the authors' clinical case of the primary bone form of articular syphilis in a 34-year-old man. 

  17. Expansion joints for LMFBR

    International Nuclear Information System (INIS)

    Dzenus, M.; Hundhausen, W.; Jansing, W.

    1980-01-01

    This discourse recounts efforts put into the SNR-2 project; specifically the development of compensation devices. The various prototypes of these compensation devices are described and the state of the development reviewed. Large Na (sodium)-heat transfer systems require a lot of valuable space if the component lay-out does not include compensation devices. So, in order to condense the spatial requirement as much as possible, expansion joints must be integrated into the pipe system. There are two basic types to suit the purpose: axial expansion joints and angular expansion joints. The expansion joints were developed on the basis of specific design criteria whereby differentiation is made between expansion joints of small and large nominal diameter. Expansion joints for installation in the sodium-filled primary piping are equipped with safety bellows in addition to the actual working bellows. Expansion joints must be designed and mounted in a manner to completely withstand seismic forces. The design must exclude any damage to the bellows during intermittent operations, that is, when sodium is drained the bellows' folds must be completely empty; otherwise residual solidified sodium could destroy the bellows when restarting. The expansion joints must be engineered on the basis of the following design data for the secondary system of the SNR project: working pressure: 16 bar; failure mode pressure: 5 events; failure mode: 5 sec., 28.5 bar, 520 deg. C; working temperature: 520 deg. C; temperature transients: 30 deg. C/sec.; service life: 200,000 h; number of load cycles: 10 4 ; material: 1.4948 or 1.4919; layer thickness of folds: 0.5 mm; angular deflection (DN 800): +3 deg. C or; axial expansion absorption (DN 600): ±80 mm; calculation: ASME class. The bellows' development work is not handled within this scope. The bellows are supplied by leading manufacturers, and warrant highest quality. Multiple bellows were selected on the basis of maximum elasticity - a property

  18. Sacroiliac Joint Interventions.

    Science.gov (United States)

    Soto Quijano, David A; Otero Loperena, Eduardo

    2018-02-01

    Sacroiliac joint (SIJ) pain is an important cause of lower back problems. Multiple SIJ injection techniques have been proposed over the years to help in the diagnosis and treatment of this condition. However, the SIJ innervation is complex and variable, and truly intra-articular injections are sometimes difficult to obtain. Different sacroiliac joint injections have shown to provide pain relief in patients suffering this ailment. Various techniques for intraarticular injections, sacral branch blocks and radiofrequency ablation, both fluoroscopy guided and ultrasound guided are discussed in this paper. Less common techniques like prolotherapy, platelet rich plasma injections and botulism toxin injections are also discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Prosthetic Joint Infection

    Science.gov (United States)

    Tande, Aaron J.

    2014-01-01

    SUMMARY Prosthetic joint infection (PJI) is a tremendous burden for individual patients as well as the global health care industry. While a small minority of joint arthroplasties will become infected, appropriate recognition and management are critical to preserve or restore adequate function and prevent excess morbidity. In this review, we describe the reported risk factors for and clinical manifestations of PJI. We discuss the pathogenesis of PJI and the numerous microorganisms that can cause this devastating infection. The recently proposed consensus definitions of PJI and approaches to accurate diagnosis are reviewed in detail. An overview of the treatment and prevention of this challenging condition is provided. PMID:24696437

  20. Imaging findings of charcot joint

    International Nuclear Information System (INIS)

    Meng Quanfei; Zhou Chunxiang; Chen Yingming; Jiang Bo

    2003-01-01

    Objective: To analyze the MRI characters of Charcot joint, and to evaluate the diagnostic value of X-ray, CT, and MRI on Charcot joint. Methods: Eight patients with 8 Charcot joints underwent X-ray, CT, and MR examinations. 6 of them had syringomyelia, 1 patient had injury of the spinal cord, and 1 case had diabetes. All 8 patients had sensory reduction or deficit in the sick extremities. Results: There were two types of Charcot joint, hypertrophic and atrophic. Radiographic and CT features of hypertrophic joint (n=3) showed hyperostotic osteosclerosis and mammoth osteophytes in the sick bones, periarticular ossification, and articular disorganization. Radiographic and CT features of atrophic joint (n=5) showed extensive bone resorption (destruction), periarticular debris, and articular disorganization. Main MRI features of Charcot joint included hydrarthrosis within joint capsule, thickened, loose, and elongated joint capsule with para-joint, peri-diaphysis, and inter-muscular extension in a pseudopodia pattern. The irregular joint capsule wall was presented as mild hypointensity on T 1 WI, slight hyper-intensity on T 2 WI, and was markedly enhanced after Gd-DTPA was administrated, which was considered as a characteristic manifestation of the lesion. Soft tissue mass containing hypo-intense stripes on both T 1 WI and T 2 WI was commonly noted adjacent to the involved joint. Conclusion: X-rays plain film is the first choice for the diagnosis of Charcot joint, and MRI is pretty useful in the diagnosis of Charcot joint

  1. Thermal and electrical joint test for the helical field coils in the Advanced Toroidal Facility

    International Nuclear Information System (INIS)

    Brown, R.L.; Johnson, R.L.

    1985-01-01

    Initial feasibility studies of a number of configurations for the Advanced Toroidal Facility (ATF) resulted in the selection of a resistive copper continuous-coil torsatron as the optimum device considering the physics program, cost, and schedule. Further conceptual design work was directed toward optimization of this configuration and, if possible, a shorter schedule. It soon became obvious that in order to shorten the schedule, a number of design and fabrication activities should proceed in parallel. This was most critical for the vacuum vessel and the helical field (HF) coils. If the HF coils were wound in place on a completed vacuum vessel, the overall schedule would be significantly (greater than or equal to12 months) longer. The approach of parallel scheduel paths requires that the HF coils be segmented into parts of less than or equal to180 0 of poloidal angle and that joints be made on a turn-by-turn basis when the segments are installed. It was obvious from the outset that the compact and complex geometry of the joint design presented a special challenge in the areas of reliability, assembly, maintenance, disassembly, and cost. Also, electrical, thermal, and force excursions are significant for these joints. A number of soldered, welded, brazed, electroplated, and bolted joints were evaluated. The evaluations examined fabrication feasibility and complexity, thermal-electrical performance at approximately two-thirds of the steady-state design conditions, and installation and assembly processes. Results of the thermal-electrical tests were analyzed and extrapolated to predict performance at peak design parameters. The final selection was a lap-type joint clamped with insulated bolts that pass through the winding packing. 3 refs., 4 figs

  2. Clinical evaluation of the Serum CrossLaps One Step ELISA, a new assay measuring the serum concentration of bone-derived degradation products of type I collagen C-telopeptides

    DEFF Research Database (Denmark)

    Christgau, S; Rosenquist, C; Alexandersen, P

    1998-01-01

    The Serum CrossLaps One Step ELISA is a sandwich assay using two monoclonal antibodies specific for a beta-aspartate form of the epitope EKAHDGGR derived from the carboxy-terminal telopeptide region of type I collagen alpha1-chain. Our objective was to assess the clinical value of the Serum Cross...

  3. Long-term, repeated dose in vitro neurotoxicity of the glutamate receptor antagonist L-AP3, demonstrated in rat hippocampal slice cultures by using continuous propidium iodide incubation

    DEFF Research Database (Denmark)

    Kristensen, Bjarne W; Blaabjerg, Morten; Noraberg, Jens

    2007-01-01

    ), which is known to be toxic in vivo after subchronic, but not acute, administration. Degenerative effects were monitored by measuring the cellular uptake of propidium iodide (PI; continuously present in the medium) and lactate dehydrogenase (LDH) leakage, and by using a panel of histological stains....... Hippocampal slices, derived from 2-3 day old rats and grown for 3 weeks, were subsequently exposed for the next 3 weeks to 0, 10 or 100microM L-AP3, with PI (2microM) in the culture medium. Exposure to 100microM L-AP3 induced severe toxicity after 4-6 days, shown by massive PI uptake, LDH leakage, changes...... in MAP2 and GFAP immunostaining, and in Nissl and Timm staining. In contrast, 10microM L-AP3 did not induce detectable neuronal degeneration. Treatment with the NMDA receptor antagonist, MK-801, or the AMPA/KA receptor antagonist NBQX, together with 100microM L-AP3, reduced neurodegeneration down...

  4. Temporomandibular Joint Septic Arthritis

    Directory of Open Access Journals (Sweden)

    Gianfranco Frojo, MD

    2018-01-01

    Full Text Available Summary:. Infection of the temporomandibular joint (TMJ is a rare pediatric condition resulting from the introduction of pathogens into the joint by hematogenous seeding, local extension, or trauma. Early recognition of the typical signs and symptoms including fever, trismus, preauricular swelling, and TMJ region tenderness are critical in order to initiate further evaluation and prevent feared complications of fibrosis, ankylosis, abnormal facial structure, or persistence of symptoms. Contrast-enhanced computed tomography with ancillary laboratory analysis including erythrocyte sedimentation rate, C-reactive protein, and white blood cell count are beneficial in confirming the suspected diagnosis and monitoring response to therapy. Initial intervention should include empiric parenteral antibiotics, early mandibular mobilization, and joint decompression to provide synovial fluid for analysis including cultures. This report describes a case of TMJ bacterial arthritis in a healthy 6-year-old male who was promptly treated nonsurgically with intravenous antibiotics and localized needle joint decompression with return to normal function after completion of oral antibiotics and physical therapy.

  5. Joint-Use Libraries

    Science.gov (United States)

    Casstevens, Susan

    2017-01-01

    The joint-use library is a place where people of all ages, interests, and income levels can find items of interest at no personal cost. The mission of A. H. Meadows Public and High School Library in Midlothian, Texas, is to offer what other public libraries provide: educational and entertainment resources to a community. Yet, the staff also wants…

  6. Keyed shear joints

    DEFF Research Database (Denmark)

    Hansen, Klaus

    This report gives a summary of the present information on the behaviour of vertical keyed shear joints in large panel structures. An attemp is made to outline the implications which this information might have on the analysis and design of a complete wall. The publications also gives a short...

  7. Jointness: A Selected Bibliography

    Science.gov (United States)

    2007-08-01

    AD-A431-767) http://handle.dtic.mil/100.2/ADA431767 Lamb , William L. Moving beyond Goldwater-Nichols: The Case for Continued Reform of the DoD...in Support of the Joint Force’." Army Aviation 55 (May 2006): 22-24. Magnuson, Stew . "Turf Battles: Strategic Command’s Expanded Portfolio

  8. Gonococcal Prosthetic Joint Infection.

    Science.gov (United States)

    Gassiep, Ian; Gilpin, Bradley; Douglas, Joel; Siebert, David

    2017-01-01

    Neisseria gonorrhoea is a common sexually transmitted infection worldwide. Disseminated gonococcal infection is an infrequent presentation and rarely can be associated with septic arthritis. Incidence of this infection is rising, both internationally and in older age groups. We present the first documented case of N. gonorrhoea prosthetic joint infection which was successfully treated with laparoscopic debridement and antimicrobial therapy.

  9. Regulation of adipocyte 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1 by CCAAT/enhancer-binding protein (C/EBP β isoforms, LIP and LAP.

    Directory of Open Access Journals (Sweden)

    Cristina L Esteves

    Full Text Available 11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1 catalyses intracellular regeneration of active glucocorticoids, notably in liver and adipose tissue. 11β-HSD1 is increased selectively in adipose tissue in human obesity, a change implicated in the pathogenesis of metabolic syndrome. With high fat (HF-feeding, adipose tissue 11β-HSD1 is down-regulated in mice, plausibly to counteract metabolic disease. Transcription of 11β-HSD1 is directly regulated by members of the CCAAT/enhancer binding protein (C/EBP family. Here we show that while total C/EBPβ in adipose tissue is unaltered by HF diet, the ratio of the C/EBPβ isoforms liver-enriched inhibitor protein (LIP and liver-enriched activator protein (LAP (C/EBPβ-LIP:LAP is increased in subcutaneous adipose. This may cause changes in 11β-HSD1 expression since genetically modified C/EBPβ((+/L mice, with increased C/EBPβ-LIP:LAP ratio, have decreased subcutaneous adipose 11β-HSD1 mRNA levels, whereas C/EBPβ(ΔuORF mice, with decreased C/EBPβ-LIP:LAP ratio, show increased subcutaneous adipose 11β-HSD1. C/EBPβ-LIP:LAP ratio is regulated by endoplasmic reticulum (ER stress and mTOR signalling, both of which are altered in obesity. In 3T3-L1 adipocytes, 11β-HSD1 mRNA levels were down-regulated following induction of ER stress by tunicamycin but were up-regulated following inhibition of mTOR by rapamycin. These data point to a central role for C/EBPβ and its processing to LIP and LAP in transcriptional regulation of 11β-HSD1 in adipose tissue. Down-regulation of 11β-HSD1 by increased C/EBPβ-LIP:LAP in adipocytes may be part of a nutrient-sensing mechanism counteracting nutritional stress generated by HF diet.

  10. Role of C/EBPβ-LAP and C/EBPβ-LIP in early adipogenic differentiation of human white adipose-derived progenitors and at later stages in immature adipocytes.

    Science.gov (United States)

    Lechner, Stefan; Mitterberger, Maria C; Mattesich, Monika; Zwerschke, Werner

    2013-01-01

    We investigated the role of the major isoforms of CCAAT enhancer binding protein β (C/EBPβ), C/EBPβ-LAP and C/EBPβ-LIP, in adipogenesis of human white adipose-derived stromal/progenitor cells (ASC). C/EBPβ gene expression was transiently induced early in adipogenesis. At later stages, in immature adipocytes, the C/EBPβ mRNA and protein levels declined. The C/EBPβ-LIP protein steady-state level decreased considerably stronger than the C/EBPβ-LAP level and the C/EBPβ-LIP half-life was significantly shorter than the C/EBPβ-LAP half-life. The turn-over of both C/EBPβ-isoforms was regulated by ubiquitin/proteasome-dependent degradation. These data suggest that the protein stability of the C/EBPβ-isoforms is differentially regulated in the course of adipogenesis and in immature adipocytes. Constitutive overexpression of C/EBPβ-LIP had antiadipogenic activity in human ASC. C/EBPβ-LAP, which promotes adipogenesis in mouse 3T3-L1 preadipocytes by directly activating expression of the adipogenic keyregulator PPARγ2, induced the expression of PPARγ2 and of the adipocyte differentiation gene product FABP4 in confluent ASC in the absence of adipogenic hormones. At later stages after hormone cocktail-induced adipogenesis, in immature adipocytes, constitutive overexpression of C/EBPβ-LAP led to reduced expression of PPARγ2 and FABP4, C/EBPα expression was downregulated and the expression of the adipocyte differentiation gene products adiponectin and leptin was impaired. These findings suggest that constitutive overexpression of C/EBPβ-LAP induces adipogenesis in human ASC and negatively regulates the expression of adipogenic regulators and certain adipocyte differentiation gene products in immature adipocytes. We conclude the regulation of both C/EBPβ gene expression and C/EBPβ-LIP and C/EBPβ-LAP protein turn-over plays an important role for the expression of adipogenic regulators and/or adipocyte differentiation genes in early adipogenic differentiation of

  11. Three-dimensional (3D) visualization of reflow porosity and modeling of deformation in Pb-free solder joints

    International Nuclear Information System (INIS)

    Dudek, M.A.; Hunter, L.; Kranz, S.; Williams, J.J.; Lau, S.H.; Chawla, N.

    2010-01-01

    The volume, size, and dispersion of porosity in solder joints are known to affect mechanical performance and reliability. Most of the techniques used to characterize the three-dimensional (3D) nature of these defects are destructive. With the enhancements in high resolution computed tomography (CT), the detection limits of intrinsic microstructures have been significantly improved. Furthermore, the 3D microstructure of the material can be used in finite element models to understand their effect on microscopic deformation. In this paper we describe a technique utilizing high resolution (< 1 μm) X-ray tomography for the three-dimensional (3D) visualization of pores in Sn-3.9Ag-0.7Cu/Cu joints. The characteristics of reflow porosity, including volume fraction and distribution, were investigated for two reflow profiles. The size and distribution of porosity size were visualized in 3D for four different solder joints. In addition, the 3D virtual microstructure was incorporated into a finite element model to quantify the effect of voids on the lap shear behavior of a solder joint. The presence, size, and location of voids significantly increased the severity of strain localization at the solder/copper interface.

  12. An analysis of a joint shear model for jointed media with orthogonal joint sets

    International Nuclear Information System (INIS)

    Koteras, J.R.

    1991-10-01

    This report describes a joint shear model used in conjunction with a computational model for jointed media with orthogonal joint sets. The joint shear model allows nonlinear behavior for both joint sets. Because nonlinear behavior is allowed for both joint sets, a great many cases must be considered to fully describe the joint shear behavior of the jointed medium. An extensive set of equations is required to describe the joint shear stress and slip displacements that can occur for all the various cases. This report examines possible methods for simplifying this set of equations so that the model can be implemented efficiently form a computational standpoint. The shear model must be examined carefully to obtain a computationally efficient implementation that does not lead to numerical problems. The application to fractures in rock is discussed. 5 refs., 4 figs

  13. Temporomandibular joint space in children without joint disease

    International Nuclear Information System (INIS)

    Larheim, T.A.

    1981-01-01

    Bilateral assessment of the temporomandibular joint space in children without joint disease is reported. Twenty-eight children were examined with conventional radiography and 23 with tomography. High prevalence of asymmetric joint spaces with both techniques indicated that great care should be taken when using narrowing or widening of the joint space as a diagnostic criterion in children with juvenile rheumatoid arthritis. Other signs, such as restricted translation of the mandibular head, and clinical symptoms should be evaluated. (Auth.)

  14. Anaerobic prosthetic joint infection.

    Science.gov (United States)

    Shah, Neel B; Tande, Aaron J; Patel, Robin; Berbari, Elie F

    2015-12-01

    In an effort to improve mobility and alleviate pain from degenerative and connective tissue joint disease, an increasing number of individuals are undergoing prosthetic joint replacement in the United States. Joint replacement is a highly effective intervention, resulting in improved quality of life and increased independence [1]. By 2030, it is predicted that approximately 4 million total hip and knee arthroplasties will be performed yearly in the United States [2]. One of the major complications associated with this procedure is prosthetic joint infection (PJI), occurring at a rate of 1-2% [3-7]. In 2011, the Musculoskeletal Infectious Society created a unifying definition for prosthetic joint infection [8]. The following year, the Infectious Disease Society of America published practice guidelines that focused on the diagnosis and management of PJI. These guidelines focused on the management of commonly encountered organisms associated with PJI, including staphylococci, streptococci and select aerobic Gram-negative bacteria. However, with the exception of Propionibacterium acnes, management of other anaerobic organisms was not addressed in these guidelines [1]. Although making up approximately 3-6% of PJI [9,10], anaerobic microorganisms cause devastating complications, and similar to the more common organisms associated with PJI, these bacteria also result in significant morbidity, poor outcomes and increased health-care costs. Data on diagnosis and management of anaerobic PJI is mostly derived from case reports, along with a few cohort studies [3]. There is a paucity of published data outlining factors associated with risks, diagnosis and management of anaerobic PJI. We therefore reviewed available literature on anaerobic PJI by systematically searching the PubMed database, and collected data from secondary searches to determine information on pathogenesis, demographic data, clinical features, diagnosis and management. We focused our search on five commonly

  15. Preservation of ancient impact ages on the R chondrite parent body: 40Ar/39Ar age of hornblende-bearing R chondrite LAP 04840

    Science.gov (United States)

    Righter, Kevin; Cosca, Michael A.; Morgan, Leah

    2016-01-01

    The hornblende- and biotite-bearing R chondrite LAP 04840 is a rare kind of meteorite possibly containing outer solar system water stored during metamorphism or postshock annealing deep within an asteroid. Because little is known regarding its age and origin, we determined 40Ar/39Ar ages on hornblende-rich separates of the meteorite, and obtained plateau ages of 4340(±40) to 4380(±30) Ma. These well-defined plateau ages, coupled with evidence for postshock annealing, indicate this meteorite records an ancient shock event and subsequent annealing. The age of 4340–4380 Ma (or 4.34–4.38 Ga) for this and other previously dated R chondrites is much older than most impact events recorded by ordinary chondrites and points to an ancient event or events that predated the late heavy bombardment that is recorded in so many meteorites and lunar samples.

  16. Longitudinal joint specifications and performance.

    Science.gov (United States)

    2012-08-01

    Deterioration of longitudinal joints is widely recognized as one of the major factors contributing to failure of asphalt pavements. Finding : ways to improve the durability of longitudinal joints will lead to improved service lives and lower life cyc...

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

    Science.gov (United States)

    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.

  18. Swivel Joint For Liquid Nitrogen

    Science.gov (United States)

    Milner, James F.

    1988-01-01

    Swivel joint allows liquid-nitrogen pipe to rotate through angle of 100 degree with respect to mating pipe. Functions without cracking hard foam insulation on lines. Pipe joint rotates on disks so mechanical stress not transmitted to thick insulation on pipes. Inner disks ride on fixed outer disks. Disks help to seal pressurized liquid nitrogen flowing through joint.

  19. Joint audits - benefit or burden?

    DEFF Research Database (Denmark)

    Holm, Claus; Thinggaard, Frank

    a joint audit regime to a single auditor/voluntary joint audit regime. The dataset used in this paper has been collected for the full population of non-financial Danish companies listed on the Copenhagen Stock Exchange (CSE) in the years 2004 and 2005. We find that a majority of firms perceive joint...

  20. Joint International Accelerator School

    CERN Multimedia

    CERN Accelerator School

    2014-01-01

    The CERN and US Particle Accelerator Schools recently organised a Joint International Accelerator School on Beam Loss and Accelerator Protection, held at the Hyatt Regency Hotel, Newport Beach, California, USA from 5-14 November 2014. This Joint School was the 13th in a series of such schools, which started in 1985 and also involves the accelerator communities in Japan and Russia.   Photo courtesy of Alfonse Pham, Michigan State University.   The school attracted 58 participants representing 22 different nationalities, with around half from Europe and the other half from Asia and the Americas. The programme comprised 26 lectures, each of 90 minutes, and 13 hours of case study. The students were given homework each day and had an opportunity to sit a final exam, which counted towards university credit. Feedback from the participants was extremely positive, praising the expertise and enthusiasm of the lecturers, as well as the high standard and quality of their lectures. Initial dis...

  1. Posterolateral elbow joint instability

    DEFF Research Database (Denmark)

    Olsen, Bo Sanderhoff; Søjbjerg, Jens Ole; Nielsen, K K

    1998-01-01

    Thirty-five osteoligamentous elbows were included in a study on the kinematics of posterolateral elbow joint instability during the pivot shift test (PST) before and after separate ligament cuttings in the lateral collateral ligament complex (LCLC). Division of the annular ligament or the lateral...... ulnar collateral ligament caused no laxity during the PST. Division of the lateral collateral ligament caused maximal laxity of 4 degrees and 23 degrees during forced PST in valgus and external rotation (supination), respectively. Cutting of the LCLC at the ulnar or the humeral insertion was necessary...... for any PST stressed elbow joint laxity to occur. Total division of the LCLC induced a maximal laxity of 7.9 degrees and 37 degrees during forced PST in valgus and external rotation (supination), respectively. This study suggests the lateral collateral ligament to be the primary soft tissue constraint...

  2. JET Joint Undertaking

    International Nuclear Information System (INIS)

    Keen, B.E.; Lallia, P.; O'Hara, G.W.; Pollard, I.E.

    1987-06-01

    The paper presents the annual report of the Joint European Torus (JET) Joint Undertaking, 1986. The report is divided into two parts: a part on the scientific and technical programme of the project, and a part setting out the administration and organisation of the Project. The first part includes: a summary of the main features of the JET apparatus, the JET experimental programme, the position of the Project in the overall Euratom programme, and how JET relates to other large fusion devices throughout the world. In addition, the technical status of JET is described, as well as the results of the JET operations in 1986. The final section of the first part outlines the proposed future programme of JET. (U.K.)

  3. Peripheral degenerative joint diseases

    Directory of Open Access Journals (Sweden)

    Nilzio Antonio da Silva

    2008-03-01

    Full Text Available Osteoarthritis, a degenerative joint disease, is the most commonrheumatic disorder mainly in a geriatric population. Manifestationsare pain, stiffness and functional loss in the affected joint.According to etiology it is classifi ed as primary (or idiopathicand secondary. Some risk factors for disease development aregenetics, race, age, sex, obesity, occupational activities andarticular biomechanics. Pathogenesis is the same for any cause orlocalization, being catabolic alterations, with synthesis, inhibitionand reparing intent of the cartilage matrix. Metalloproteinases andcytokines (IL-1,IL-6,TNF-α actions promote infl ammatory reactionand cartilage degradation. Pain, the most important symptom,does not correlate with radiologic fi ndings. Peripheral osteoarthritisoccurs predominantly in the knee, hip and hand. Diagnosis is basedon clinical features, laboratorial tests and radiological changes.Rheumatological associations’ guidelines for treatment includenon-pharmacologic (education, physiotherapy, assistive devices,and pharmacologic (analgesics, anti-infl ammatory drugs therapyand surgery. Arthroplasty seems to work better than medicines, butshould be used if other treatments have failed.

  4. Joint Counterdrug Operations

    Science.gov (United States)

    1998-02-17

    Chapter II Joint Pub 3-07.4 cocaine HCL production. There are over 150 groups trafficking in cocaine, with cartels centered in Medellin and Cali. These...nontraditional mapping products and several digital mapping data bases for geological information and intelligence systems. • Defense Security Assistance Agency...variety of means. Dissemination means include personal contact, physical transfer or courier of hard copy textual and graphic materials, digital and

  5. Jet Joint Undertaking

    International Nuclear Information System (INIS)

    Keen, B.E.; O'Hara, G.W.; Pollard, I.E.

    1988-07-01

    The paper presents the Jet Joint Undertaking annual report 1987. A description is given of the JET and Euratom and International Fusion Programmes. The technical status of JET is outlined, including the development and improvements made to the system in 1987. The results of JET Operation in 1987 are described within the areas of: density effects, temperature improvements, energy confinement studies and other material effects. The contents also contain a summary of the future programme of JET. (U.K.)

  6. Joint Fire Support

    Science.gov (United States)

    2010-06-30

    intelligence application package for theater battle management core system ( TBMCS ) functionality at wing and squadron levels. The automated four... TBMCS , Joint Surveillance and Target Attack Radar System (Ground Control Station), and Global Command and Control System, as well as with Allied FA...The TBMCS is a force level integrated air C2 system. TBMCS provides hardware, software, and communications interfaces to support the preparation

  7. Australias Joint Approach

    Science.gov (United States)

    2015-09-01

    headquarters command and control architecture , including consideration of our suggestion of formalising the strategic J staff system for the support of... architecture … to support successful joint operations.”28 Our analysis involving consultation with a number of senior officers indicates that a more...transported armies into battle since ancient Egyptian times.57 The cooperation between the Royal Australian Navy (RAN) and the Australian Army began with

  8. Laboratory characterization of rock joints

    International Nuclear Information System (INIS)

    Hsiung, S.M.; Kana, D.D.; Ahola, M.P.; Chowdhury, A.H.; Ghosh, A.

    1994-05-01

    A laboratory characterization of the Apache Leap tuff joints under cyclic pseudostatic and dynamic loads has been undertaken to obtain a better understanding of dynamic joint shear behavior and to generate a complete data set that can be used for validation of existing rock-joint models. Study has indicated that available methods for determining joint roughness coefficient (JRC) significantly underestimate the roughness coefficient of the Apache Leap tuff joints, that will lead to an underestimation of the joint shear strength. The results of the direct shear tests have indicated that both under cyclic pseudostatic and dynamic loadings the joint resistance upon reverse shearing is smaller than that of forward shearing and the joint dilation resulting from forward shearing recovers during reverse shearing. Within the range of variation of shearing velocity used in these tests, the shearing velocity effect on rock-joint behavior seems to be minor, and no noticeable effect on the peak joint shear strength and the joint shear strength for the reverse shearing is observed

  9. Microstructure and mechanical properties of joints in sintered SiC fiber-bonded ceramics brazed with Ag-Cu-Ti alloy

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Mrityunjay [Ohio Aerospace Institute, Cleveland, OH 44142 (United States); Matsunaga, Tadashi [R and D Division, Ube Industries, Ltd., Ube-shi, Yamaguchi 755-8633 (Japan); Lin, Hua-Tay [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831-6068 (United States); Asthana, Rajiv, E-mail: asthanar@uwstout.edu [Department of Engineering and Technology, 326 Fryklund Hall, University of Wisconsin-Stout, Menomonie, WI 54751 (United States); Ishikawa, Toshihiro [R and D Division, Ube Industries, Ltd., Ube-shi, Yamaguchi 755-8633 (Japan)

    2012-11-15

    Active metal brazing of a new high thermal conductivity sintered SiC-polycrystalline fiber-bonded ceramic (SA-Tyrannohex{sup Registered-Sign }) has been carried out using a Ti-containing Ag-Cu active braze alloy (Cusil-ABA{sup Registered-Sign }). The brazed composite joints were characterized using scanning electron microscopy coupled with energy-dispersive X-ray spectrometry (SEM-EDS). The results show that this material can be successfully joined using judiciously selected off-the shelf active braze alloys to yield metallurgically sound joints possessing high integrity. Uniform and continuous joints were obtained irrespective of differences in the fiber orientation in the substrate material. Detailed interfacial microanalysis showed that the titanium reacts with C and Si to form TiC layer and a Ti-Si compound, respectively. Furthermore, the evaluation of shear strength of the joints was also conducted at ambient and elevated temperatures in air using the single-lap offset (SLO) shear test. The perpendicular-type SA-Tyrannohex joints exhibited apparent shear strengths of about 42 MPa and 25 MPa at 650 Degree-Sign C and 750 Degree-Sign C, respectively. The fracture at the higher temperature occurred at the interface between the reaction-formed TiC layer and braze. This might be caused by generation of stress intensity when a shear stress was applied, according to {mu}-FEA simulation results.

  10. Prediction of fracture toughness and durability of adhesively bonded composite joints with undesirable bonding conditions

    Science.gov (United States)

    Musaramthota, Vishal

    Advanced composite materials have enabled the conventional aircraft structures to reduce weight, improve fuel efficiency and offer superior mechanical properties. In the past, materials such as aluminum, steel or titanium have been used to manufacture aircraft structures for support of heavy loads. Within the last decade or so, demand for advanced composite materials have been emerging that offer significant advantages over the traditional metallic materials. Of particular interest in the recent years, there has been an upsurge in scientific significance in the usage of adhesively bonded composite joints (ABCJ's). ABCJ's negate the introduction of stress risers that are associated with riveting or other classical techniques. In today's aircraft transportation market, there is a push to increase structural efficiency by promoting adhesive bonding to primary joining of aircraft structures. This research is focused on the issues associated with the durability and related failures in bonded composite joints that continue to be a critical hindrance to the universal acceptance of ABCJ's. Of particular interest are the short term strength, contamination and long term durability of ABCJ's. One of the factors that influence bond performance is contamination and in this study the influence of contamination on composite-adhesive bond quality was investigated through the development of a repeatable and scalable surface contamination procedure. Results showed an increase in the contaminant coverage area decreases the overall bond strength significantly. A direct correlation between the contaminant coverage area and the fracture toughness of the bonded joint was established. Another factor that influences bond performance during an aircraft's service life is its long term strength upon exposure to harsh environmental conditions or when subjected to severe mechanical loading. A test procedure was successfully developed in order to evaluate durability of ABCJ's comprising severe

  11. CO2 laser welding of galvanized steel sheets using vent holes

    International Nuclear Information System (INIS)

    Chen Weichiat; Ackerson, Paul; Molian, Pal

    2009-01-01

    Joining of galvanized steels is a challenging issue in the automotive industry because of the vaporization of zinc at 906 deg. C during fusion welding of steel (>1530 deg. C). In this work, hot-dip galvanized steel sheets of 0.68 mm thick (24-gage) were pre-drilled using a pulsed Nd:YAG laser to form vent holes along the weld line and then seam welded in the lap-joint configuration using a continuous wave CO 2 laser. The welds were evaluated through optical and scanning electron microscopy and tensile/hardness tests. The vent holes allowed zinc vapors to escape through the weld zone without causing expulsion of molten metal, thereby eliminating the defects such as porosity, spatter, and loss of penetration. In addition, riveting of welds occurred so long as the weld width was greater than the hole diameter that in turn provided much higher strength over the traditional 'joint gap' method

  12. Mechanical characteristics of connection for GFRP plates using tapping screws

    Science.gov (United States)

    Inoue, Yuya; Duong, Nguyen Ngoc; Satake, Chito; Matsumoto, Yukihiro

    2017-10-01

    FRP material has good characteristics such as light-weight, high-strength and high-corrosion resistance. Light-weight structure possesses some advantages over the rational constructing procedure such as self-building structures. In recent years, mechanical characteristics of FRP joints using bolts and/or rivet are investigated in detail, and they are used in many FRP structures. However, the bolts lack bearing strength compared with material strength and the joint needs the prepared bolt hole. In this paper, an alternative joint system for FRP structures using tapping screw is proposed and mechanical characteristics are investigated through experiment. Tapping screw has some advantages; easy-to-use, light-weight and high bearing strength. Then, the results of double-lapped tensile shear tests having one, four and eight tapping screws along longitudinal direction are shown. Moreover, it is shown that longitudinal stress distribution is approximately corresponding to the theoretical stress distribution of double-lapped adhesively bonded joints. Based on these, it is proposed that joint strength can be estimated by using the present calculation method.

  13. Temporomandibular joint motion

    International Nuclear Information System (INIS)

    Maeda, M.; Kawamura, Y.; Matsuda, T.; Itou, S.; Odori, T.; Ishii, Y.; Torizuka, K.

    1990-01-01

    This paper evaluates MR imaging with the therapeutic effect after splint therapy in internal derangement of the temporomandibular joint (TMJ). Fifteen patients (19 TMJs) with internal derangement of the TMJ and five normal volunteers (10 TMJs) were examined with sagittal T1-weighted spin-echo and gradient recalled acquisition in a steady state (GRASS) MR imaging. MR studies of the patients undergoing splint therapy were performed with an without splints. Pseudodynamic images of TMJ motion provide information that was not available from spin-echo T1-weighted images

  14. Joint Advisory Appeals Board

    CERN Multimedia

    2013-01-01

    The Joint Advisory Appeals Board has examined the internal appeal lodged by a former member of the personnel, a beneficiary of the CERN Pension Fund, against the calculation of his pension in the framework of the Progressive Retirement Programme.   The person concerned has not objected to the report of the Board and the final decision of the Director-General being brought to the attention of the members of the personnel. In application of Article R VI 1.18 of the Staff Regulations, these documents will therefore be available from 26 July to 11 August 2013 at the following link. HR Department Head Office

  15. JOINT ADVISORY APPEALS BOARD

    CERN Multimedia

    Human Resources Division

    2002-01-01

    The Joint Advisory Appeals Board was convened to examine the appeal lodged by Mr Luc Vos with regard to advancement. As the appellant has not objected, the report of the Board and the final decision of the Director-General are brought to the notice of the personnel in accordance with Article R VI 1.20 of the Staff Regulations. The relevant documents will therefore be posted on the notice boards of the Administration Building (N° 60) from 14 to 28 June 2002. Human Resources Division Tel. 74128

  16. Joint Advisory Appeals Board

    CERN Multimedia

    HR Department

    2008-01-01

    The Joint Advisory Appeals Board has examined the internal appeal lodged by a member of the personnel against the decision to grant him only a periodic one-step advancement for the 2006 reference year. The person concerned has not objected to the report of the Board and the final decision of the Director-General being brought to the attention of the members of the personnel. In application of Article R VI 1.18 of the Staff Regulations, these documents will therefore be posted on the notice board of the Main building (bldg. 500) from 1 September to 14 September 2008. Human Resources Department (73911)

  17. Joint Advisory Appeals Board

    CERN Multimedia

    2003-01-01

    The Joint Advisory Appeals Board was convened to examine the appeal lodged by Mr Poul Frandsen concerning his assimilation into the new career structure. As the appellant has not objected, the report of the Board and the final decision of the Director-General are brought to the notice of the personnel in accordance with Article R VI 1.20 of the Staff Regulations. The relevant documents will therefore be posted on the notice boards of the Administration Building (N° 60) from 13 to 24 January 2003. Human Resources Division Tel. 74128

  18. JOINT ADVISORY APPEALS BOARD

    CERN Multimedia

    Personnel Division

    1999-01-01

    The Joint Advisory Appeals Board was convened to examine the appeal lodged by Mr Joào Bento with regard to residential category. As the appellant has not objected, the recommendations of the Board and the final decision of the Director-General are brought to the notice of the personnel in accordance with Article RÊVIÊ1.20 of the Staff Regulations.The relevant documents will therefore be posted on the notice boards of the Administration Building (N¡ 60) from 29 October to 12 November 1999.Personnel DivisionTel. 74128

  19. Joint Advisory Appeals Board

    CERN Multimedia

    HR Department

    2006-01-01

    The Joint Advisory Appeals Board was convened to examine an appeal lodged by a member of the personnel with regard to advancement. The person concerned has requested that the report of the Board and the final decision of the Director-General be brought to the notice of the personnel in accordance with Article R VI 1.20 of the Staff Regulations. The relevant documents will therefore be posted on the notice boards of the Administration Building (No. 60) from 24 March to 10 April 2006. Human Resources Department Tel. 74128

  20. Joint Advisory Appeals Board

    CERN Multimedia

    HR Department

    2007-01-01

    The Joint Advisory Appeals Board was convened to examine an internal appeal lodged by a member of the personnel with regard to the decision not to grant him an indefinite contract. The person concerned has requested that the report of the Board and the final decision of the Director-General be brought to the notice of the members of the personnel, in accordance with Article R VI 1.18 of the Staff Regulations. The relevant documents will therefore be posted on the notice board of the Main building (Bldg. 60) from 24 September to 7 October 2007. Human Resources Department

  1. JOINT ADVISORY APPEALS BOARD

    CERN Multimedia

    Human Resources Division

    2001-01-01

    The Joint Advisory Appeals Board was convened to examine the appeal lodged by Mr Olivier Francis Martin with regard to indefinite contract. As the appellant has not objected, the report of the Board and the final decision of the Director-General are brought to the notice of the personnel in accordance with Article R VI 1.20 of the Staff Regulations. The relevant documents will therefore be posted on the notice boards of the Administration Building (N° 60) from 8 to 25 June 2001.

  2. JOINT ADVISORY APPEALS BOARD

    CERN Multimedia

    Human Resources Division

    2002-01-01

    The Joint Advisory Appeals Board was convened to examine the appeal lodged by Mr Jack Blanchard with regard to 'non recognition of specific functions'. As the appellant has not objected, the report of the Board and the final decision of the Director-General are brought to the notice of the personnel in accordance with Article R VI 1.20 of the Staff Regulations. The relevant documents will therefore be posted on the notice boards of the Administration Building (N° 60) from 12th to 26th April 2002. Human Resources Division Tel. 74128

  3. Joint Advisory Appeals Board

    CERN Multimedia

    2003-01-01

    The Joint Advisory Appeals Board was convened to examine the appeal lodged by Mrs Judith Igo-Kemenes concerning the application of procedures foreseen by Administrative Circular N§ 26 (Rev. 3). As the appellant has not objected, the report of the Board and the final decision of the Director-General are brought to the notice of the personnel in accordance with Article R VI 1.20 of the Staff Regulations. The relevant documents will therefore be posted on the notice boards of the Administration Building (N° 60) from 6 to 20 June 2003. Human Resources Division Tel. 74128

  4. Joint Advisory Appeals Board

    CERN Multimedia

    2004-01-01

    The Joint Advisory Appeals Board was convened to examine the appeal lodged by Mrs Maria DIMOU with regard to a periodic one-step increase. As the appellant has not objected, the report of the Board and the final decision of the Director-General are brought to the notice of the personnel in accordance with Article R VI 1.20 of the Staff Regulations. The relevant documents will therefore be posted on the notice boards of the Administration Building (N° 60) from 30 April to 14 May 2004. Human Resources Department Tel. 74128

  5. JOINT ADVISORY APPEALS BOARD

    CERN Multimedia

    Human Resources Division

    2001-01-01

    The Joint Advisory Appeals Board was convened to examine the appeal lodged by Mr Joël Lahaye with regard to non-resident allowance. As the appellant has not objected, the report of the Board and the final decision of the Director-General are brought to the notice of the personnel in accordance with Article R VI 1.20 of the Staff Regulations. The relevant documents will therefore be posted on the notice boards of the Administration Building (N° 60) from 18 May to 1st June 2001.

  6. Joint Advisory Appeals Board

    CERN Multimedia

    HR Department

    2008-01-01

    The Joint Advisory Appeals Board has examined the internal appeal lodged by a member of the personnel with regard to the decision not to award him a periodic one-step advancement for the 2006 reference year. The person concerned has not objected to the report of the Board and the final decision of the Director-General being brought to the notice of the members of the personnel. In application of Article R VI 1.18 of the Staff Regulations, these documents will therefore be posted on the notice board of the Main building (Bldg. 500) from 17 March to 30 March 2008. Human Resources Department Tel. 73911

  7. JOINT ADVISORY APPEALS BOARD

    CERN Multimedia

    Human Resources Division

    2002-01-01

    The Joint Advisory Appeals Board was convened to examine the appeal lodged by Mr Bertrand Nicquevert with regard to the non-resident allowance. As the appellant has not objected, the report of the Board and the final decision of the Director-General are brought to the notice of the personnel in accordance with Article R VI 1.20 of the Staff Regulations. The relevant documents will therefore be posted on the notice boards of the Administration Building (N° 60) from 29 November to 13 December 2002. Human Resources Division Tel. 74128

  8. JOINT ADVISORY APPEALS BOARD

    CERN Multimedia

    Human Resources Division

    2002-01-01

    The Joint Advisory Appeals Board was convened to examine the appeal lodged by Mr Antonio Millich with regard to advancement. As the appellant has not objected, the report of the Board and the final decision of the Director-General are brought to the notice of the personnel in accordance with Article R VI 1.20 of the Staff Regulations. The relevant documents will therefore be posted on the notice boards of the Administration Building (N° 60) from 27 September to 11 October 2002. Human Resources Division Tel. 74128

  9. Joint Advisory Appeals Board

    CERN Multimedia

    Human Resources Department

    2005-01-01

    The Joint Advisory Appeals Board was convened to examine an appeal lodged by a member of the personnel with regard to a periodic one-step increase. As the appellant has not objected, the report of the Board and the final decision of the Director-General are brought to the notice of the personnel in accordance with Article R VI 1.20 of the Staff Regulations. The relevant documents will therefore be posted on the notice boards of the Administration Building (N° 60) from 1 to 15 April 2005. Human Resources Department Tel. 74128

  10. Joint Advisory Appeals Board

    CERN Multimedia

    HR Department

    2008-01-01

    The Joint Advisory Appeals Board has examined the internal appeal lodged by a member of the personnel against the decision to grant him only a periodic one-step advancement for the 2006 reference year. The person concerned has not objected to the report of the Board and the final decision of the Director-General being brought to the attention of the members of the personnel. In application of Article R VI 1.18 of the Staff Regulations, these documents will therefore be posted on the notice board of the Main Building (Bldg. 500) from 1 September to 14 September 2008. Human Resources Department (73911)

  11. JOINT ADVISORY APPEALS BOARD

    CERN Multimedia

    Human Resources Division

    2002-01-01

    The Joint Advisory Appeals Board was convened to examine the appeal lodged by Mr Gert Jan Bossen with regard to dependent child allowance. As the appellant has not objected, the report of the Board and the final decision of the Director-General are brought to the notice of the personnel in accordance with Article R VI 1.20 of the Staff Regulations. The relevant documents will therefore be posted on the notice boards of the Administration Building (N° 60) from 1st to 15 March 2002. Human Resources Division Tel. 74128

  12. Joint Advisory Appeals Board

    CERN Multimedia

    HR Department

    2008-01-01

    The Joint Advisory Appeals Board has examined the internal appeal lodged by a member of the personnel with regard to the decision not to grant him an indefinite contract. The person concerned has not objected to the report of the Board and the final decision of the Director-General being brought to the notice of the members of the personnel. In application of Article R VI 1.18 of the Staff Regulations, these documents will therefore be posted on the notice board of the Main Building (Bldg. 500) from 26 May to 6 June 2008. Human Resources Department (73911)

  13. JOINT ADVISORY APPEALS BOARD

    CERN Multimedia

    Human Resources Division

    2002-01-01

    The Joint Advisory Appeals Board was convened to examine the appeal lodged by Mr Serge Peraire with regard to exceptional advancement. As the appellant has not objected, the report of the Board and the final decision of the Director-General are brought to the notice of the personnel in accordance with Article R VI 1.20 of the Staff Regulations. The relevant documents will therefore be posted on the notice boards of the Administration Building (N° 60) from 17 to 31 May 2002. Human Resources Division Tel. 74128

  14. Joint Advisory Appeals Board

    CERN Multimedia

    HR Department

    2008-01-01

    The Joint Advisory Appeals Board was convened to examine an internal appeal lodged by a member of the personnel with regard to the decision not to grant him an indefinite contract. The person concerned has not objected to the report of the Board and the final decision of the Director-General being brought to the notice of the members of the personnel, in accordance with Article R VI 1.18 of the Staff Regulations. These documents will therefore be posted on the notice board of the Main Building (Bldg. 60) from 21 January to 3 February 2008. Human Resources Department (73911)

  15. Patellofemoral joint motion

    International Nuclear Information System (INIS)

    Stanford, W.; Phelan, J.; Albright, J.; Kathol, M.; Rooholamini, S.A.; El-Khoury, G.Y.; Palutsis, G.R.

    1988-01-01

    This paper describes the use of ultrafast computed tomography (CT) to obtain dynamic images of the patellofemoral joint during active motion. Thirty-eight patients underwent measurements of tangent offset, bisect offset, congruence angle, patellar tilt angle, lateral patellofemoral angle, sulcus angle, and sulcus depth made during leg movement. Selected parameters were compared with Merchant views. Significant correlations were obtained between Merchant views and comparable ultrafast CT views for all parameters except sulcus angle. Correlations between the other parameters were poor. Cine strips showed two patterns of movement; the patella remained centered either throughout excursion or until the last 20 0 of full extension, when it would sublux laterally

  16. Joint Advisory Appeals Board

    CERN Multimedia

    2003-01-01

    The Joint Advisory Appeals Board was convened to examine the appeal lodged by Mr Aloïs Girardoz with regard to classification and advancement. As the appellant has not objected, the Board's report and the Director-General's decision will be brought to the notice of the personnel in accordance with Article R VI 1.20 of the Staff Regulations. The relevant documents will therefore be posted on the notice boards of the Administration Building (N° 60) from 15 to 29 August 2003. Human Resources Division Tel. 74128

  17. Glenohumeral Joint Injections

    Science.gov (United States)

    Gross, Christopher; Dhawan, Aman; Harwood, Daniel; Gochanour, Eric; Romeo, Anthony

    2013-01-01

    Context: Intra-articular injections into the glenohumeral joint are commonly performed by musculoskeletal providers, including orthopaedic surgeons, family medicine physicians, rheumatologists, and physician assistants. Despite their frequent use, there is little guidance for injectable treatments to the glenohumeral joint for conditions such as osteoarthritis, adhesive capsulitis, and rheumatoid arthritis. Evidence Acquisition: We performed a comprehensive review of the available literature on glenohumeral injections to help clarify the current evidence-based practice and identify deficits in our understanding. We searched MEDLINE (1948 to December 2011 [week 1]) and EMBASE (1980 to 2011 [week 49]) using various permutations of intra-articular injections AND (corticosteroid OR hyaluronic acid) and (adhesive capsulitis OR arthritis). Results: We identified 1 and 7 studies that investigated intra-articular corticosteroid injections for the treatment of osteoarthritis and adhesive capsulitis, respectively. Two and 3 studies investigated the use of hyaluronic acid in osteoarthritis and adhesive capsulitis, respectively. One study compared corticosteroids and hyaluronic acid injections in the treatment of osteoarthritis, and another discussed adhesive capsulitis. Conclusion: Based on existing studies and their level of evidence, there is only expert opinion to guide corticosteroid injection for osteoarthritis as well as hyaluronic acid injection for osteoarthritis and adhesive capsulitis. PMID:24427384

  18. Phytomedicine in Joint Disorders

    Directory of Open Access Journals (Sweden)

    Dorin Dragos

    2017-01-01

    Full Text Available Chronic joint inflammatory disorders such as osteoarthritis and rheumatoid arthritis have in common an upsurge of inflammation, and oxidative stress, resulting in progressive histological alterations and disabling symptoms. Currently used conventional medication (ranging from pain-killers to biological agents is potent, but frequently associated with serious, even life-threatening side effects. Used for millennia in traditional herbalism, medicinal plants are a promising alternative, with lower rate of adverse events and efficiency frequently comparable with that of conventional drugs. Nevertheless, their mechanism of action is in many cases elusive and/or uncertain. Even though many of them have been proven effective in studies done in vitro or on animal models, there is a scarcity of human clinical evidence. The purpose of this review is to summarize the available scientific information on the following joint-friendly medicinal plants, which have been tested in human studies: Arnica montana, Boswellia spp., Curcuma spp., Equisetum arvense, Harpagophytum procumbens, Salix spp., Sesamum indicum, Symphytum officinalis, Zingiber officinalis, Panax notoginseng, and Whitania somnifera.

  19. Jointly Sponsored Research Program

    Energy Technology Data Exchange (ETDEWEB)

    Everett A. Sondreal; John G. Hendrikson; Thomas A. Erickson

    2009-03-31

    U.S. Department of Energy (DOE) Cooperative Agreement DE-FC26-98FT40321 funded through the Office of Fossil Energy and administered at the National Energy Technology Laboratory (NETL) supported the performance of a Jointly Sponsored Research Program (JSRP) at the Energy & Environmental Research Center (EERC) with a minimum 50% nonfederal cost share to assist industry in commercializing and effectively applying highly efficient, nonpolluting energy systems that meet the nation's requirements for clean fuels, chemicals, and electricity in the 21st century. The EERC in partnership with its nonfederal partners jointly performed 131 JSRP projects for which the total DOE cost share was $22,716,634 (38%) and the nonfederal share was $36,776,573 (62%). Summaries of these projects are presented in this report for six program areas: (1) resource characterization and waste management, (2) air quality assessment and control, (3) advanced power systems, (4) advanced fuel forms, (5) value-added coproducts, and (6) advanced materials. The work performed under this agreement addressed DOE goals for reductions in CO{sub 2} emissions through efficiency, capture, and sequestration; near-zero emissions from highly efficient coal-fired power plants; environmental control capabilities for SO{sub 2}, NO{sub x}, fine respirable particulate (PM{sub 2.5}), and mercury; alternative transportation fuels including liquid synfuels and hydrogen; and synergistic integration of fossil and renewable resources.

  20. Radiosynoviorthesis in haemaphilic joint disease

    International Nuclear Information System (INIS)

    Pad Bosch, P.J.I. van't; Putte, L.B.A. van de; Boerbooms, A.M.T.; Geerdink, P.J.

    1981-01-01

    The effects of radiosynoviorthesis on chronic haemophilic arthropathic joints were studied in six patients with severe haemophilia by a follow up study which spanned two and a half years. On clinical grounds the treatment was successful because pain and bleeding frequency diminished, although radiographic examination showed further deterioration of the treated joint. Chromosome damage was not detected. We conclude that radiosynoviorthesis is apparently changing the bleeding pattern of articular tissues without arresting the destruction and deformation of joints. (orig.) [de

  1. Structural Evaluation of Riveted Spillway Gates

    Science.gov (United States)

    1994-06-01

    EngineerWaewyExemntstaio) RE8-C-p .•i1 8c.- Tcnclrpr ERC-3 TA7~o W34noREM-C-4 1. Hda ulcgte.2 Silays --~mm Dttm esloing-n adontubcation -if Evlain...A7 steel also was restricted to open- hearth or electric furnace production, and excluded the older acid -besse- mer production. These compositional...alternately wet and dry cycles. d. pH of the river water. Corrosion usually occurs at low pH (highly acidic conditions) and at high pH (highly alkaline

  2. Leveraging Technology for Joint Training

    National Research Council Canada - National Science Library

    Walker, Jack

    1997-01-01

    .... While this innovation will have a significant impact on education and training, it will not fulfill its potential unless joint and component commanders understand what the technologies represent...

  3. Demand Response Potential for California SubLAPs and Local Capacity Planning Areas: An Addendum to the 2025 California Demand Response Potential Study – Phase 2

    Energy Technology Data Exchange (ETDEWEB)

    Alstone, Peter [Humboldt State Univ., Arcata, CA (United States). Schatz Energy Research Center; Potter, Jennifer [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Piette, Mary Ann [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Schwartz, Peter [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Berger, Michael A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Dunn, Laurel N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Smith, Sarah J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Sohn, Michael D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Aghajanzadeh, Arian [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Stensson, Sofia [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Szinai, Julia [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-04-01

    The 2025 California Demand Response Potential Study Phase 2 Report1 was released on March 1, 2017, and described a range of pathways for Demand Response (DR) to support a clean, stable, and cost-effective electric grid for California. One of the Report’s key findings was that while there appears to be very low future value for untargeted DR Shed aimed at system-wide peak load conditions, there could be significant value for locally focused Shed resources. Although the dynamics of renewable capacity expansion have reduced the pressure to build new thermal generation in general, there are still transmission-constrained areas of the state where load growth needs to be managed with the addition of new local capacity, which could include DERs and/or DR. This Addendum to the Phase 2 Report presents a breakdown of the expected future “Local Shed” DR potential at a finer geographic resolution than what is available in the original report, with results summarized by SubLAP and Local Capacity Area (LCA).

  4. Proteomic profiling of antibody-inducing immunogens in tumor tissue identifies PSMA1, LAP3, ANXA3, and maspin as colon cancer markers

    Science.gov (United States)

    Yang, Qian; Roehrl, Michael H.; Wang, Julia Y.

    2018-01-01

    We hypothesized that cancer tissue immunogens – antigens capable of inducing specific antibody production in patients – are promising targets for development of precision diagnostics and humoral immunotherapies. We developed an innovative immuno-proteomic strategy and identified new immunogenic markers of colon cancer. Proteins from cancers and matched normal tissues were separated by 2D gel electrophoresis and blotted with serum antibodies from the same patients. Antibody-reactive proteins were sequenced by mass spectrometry and validated by Western blotting and immunohistochemistry. 170 serum antibody-reactive proteins were identified only in cancerous but not matched normal. Among these, proteasome subunit alpha type 1 (PSA1), leucine aminopeptidase 3 (LAP3), annexin A3 (ANXA3), and maspin (serpin B5) were reproducibly found in tissues from three patients. Differential expression patterns were confirmed in samples from eight patients with various stages of colon adenocarcinoma and liver metastases. These tumor-resident proteins and/or their associated serum antibodies may be promising markers for colon cancer screening and early diagnosis. Furthermore, tumor tissue-specific antibodies could potentially be exploited as immunotherapeutic targets against cancer. More generally, proteomic profiling of antibody-inducing cancer-associated immunogens represents a powerful generic method for uncovering the tumor antigen-ome, i.e., the totality of immunogenic tumor-associated proteins. PMID:29423100

  5. The Mental Health Leadership and Advocacy Program (mhLAP): a pioneering response to the neglect of mental health in Anglophone West Africa.

    Science.gov (United States)

    Abdulmalik, Jibril; Fadahunsi, Woye; Kola, Lola; Nwefoh, Emeka; Minas, Harry; Eaton, Julian; Gureje, Oye

    2014-01-27

    Developing countries in Africa and other regions share a similar profile of insufficient human resources for mental health, poor funding, a high unmet need for services and a low official prioritisation of mental health. This situation is worsened by misconceptions about the causes of mental disorders, stigma and discrimination that frequently result in harmful practices against persons with mental illness. Previous explorations of the required response to these challenges have identified the need for strong leadership and consistent advocacy as potential drivers of the desired change. The Mental Health Leadership and Advocacy Program (mhLAP) is a project that aims to provide and enhance the acquisition of skills in mental health leadership, service development, advocacy and policy planning and to build partnerships for action. Launched in 2010 to serve the Anglophone countries of The Gambia, Ghana, Liberia, Nigeria, Sierra Leone, this paper describes the components of the program, the experience gained since its initiation, and the achievements made during the three years of its implementation. These achievements include: 1) the annual training in mental health leadership and advocacy which has graduated 96 participants from 9 different African countries and 2) the establishment of a broad coalition of service user groups, non-governmental organizations, media practitioners and mental health professionals in each participating country to implement concerted mental health advocacy efforts that are focused on country-specific priorities.

  6. Plant-based oral tolerance to hemophilia therapy employs a complex immune regulatory response including LAP+CD4+ T cells.

    Science.gov (United States)

    Wang, Xiaomei; Su, Jin; Sherman, Alexandra; Rogers, Geoffrey L; Liao, Gongxian; Hoffman, Brad E; Leong, Kam W; Terhorst, Cox; Daniell, Henry; Herzog, Roland W

    2015-04-09

    Coagulation factor replacement therapy for the X-linked bleeding disorder hemophilia is severely complicated by antibody ("inhibitor") formation. We previously found that oral delivery to hemophilic mice of cholera toxin B subunit-coagulation factor fusion proteins expressed in chloroplasts of transgenic plants suppressed inhibitor formation directed against factors VIII and IX and anaphylaxis against factor IX (FIX). This observation and the relatively high concentration of antigen in the chloroplasts prompted us to evaluate the underlying tolerance mechanisms. The combination of oral delivery of bioencapsulated FIX and intravenous replacement therapy induced a complex, interleukin-10 (IL-10)-dependent, antigen-specific systemic immune suppression of pathogenic antibody formation (immunoglobulin [Ig] 1/inhibitors, IgE) in hemophilia B mice. Tolerance induction was also successful in preimmune mice but required prolonged oral delivery once replacement therapy was resumed. Orally delivered antigen, initially targeted to epithelial cells, was taken up by dendritic cells throughout the small intestine and additionally by F4/80(+) cells in the duodenum. Consistent with the immunomodulatory responses, frequencies of tolerogenic CD103(+) and plasmacytoid dendritic cells were increased. Ultimately, latency-associated peptide expressing CD4(+) regulatory T cells (CD4(+)CD25(-)LAP(+) cells with upregulated IL-10 and transforming growth factor-β (TGF-β) expression) as well as conventional CD4(+)CD25(+) regulatory T cells systemically suppressed anti-FIX responses. © 2015 by The American Society of Hematology.

  7. Temporomandibular joint movement

    International Nuclear Information System (INIS)

    Maeda, M.; Itou, S.; Ishii, Y.; Yamamoto, K.; Kawamura, Y.; Matsuda, T.; Hayashi, N.; Ishii, J.

    1992-01-01

    Ten temporomandibular joints (TMJs) of 5 healthy volunteers and 19 TMJs of internal derangements in 16 patients with splint therapy were examined with MR imaging. T1-weighted images were obtained only in the closed mouth position, and gradient recalled acquisition in steady state (GRASS) images were obtained in active opening and closing phases, allowing a pseudodynamic display of TMJ movement. All patients received protrusive splint treatment. The usefulness of MR imaging to assess the efficacy of splint therapy was evaluated. Corrected disk position with the splint in place was clearly demonstrated in 9 TMJs, corresponding with elimination of reciprocal clicking. Ten other TMJs of anterior disk displacement without reduction showed uncorrected disk position by the splint. This information could confirm the therapeutic efficacy, or suggest other treatment alternatives. GRASS MR imaging can provide accurate and physiologic information about disk function in initial and follow-up assessment of protrusive splint therapy. (orig.)

  8. JOINT ADVISORY APPEALS BOARD

    CERN Multimedia

    Human Resources Division

    2001-01-01

    The Joint Advisory Appeals Board was convened to examine the appeal lodged by Mr Neil Calder, Mrs Sudeshna Datta Cockerill, Mrs Andrée Fontbonne, Mrs Moniek Laurent and Mr Ulrich Liptow with regard to membership in the Pension Fund under the period with a Paid Associate contract, appeals dealt with on a collective basis. As the appellants have not objected, the report of the Board and the final decision of the Director-General are brought to the notice of the personnel in accordance with Article R VI 1.20 of the Staff Regulations. The relevant documents will therefore be posted on the notice boards of the Administration Building (N° 60) from 10 to 31 August 2001.

  9. Temporomandibular joint arthrography

    International Nuclear Information System (INIS)

    Choi, Hyung Sik; Lee, Kyung Soo; Kim, Myoung Joon; Jun, Young Hwan; Chang, Duk Soo; Jung, Don Young; Jung, In Won

    1988-01-01

    The stress and occlusion disturbance are very important etiologic factors in the temporomandibular joint (TMJ) pain dysfunction syndromes. Authors performed TMJ arthrograms in the patients with TMJ problem such as pain, click sound, limited motion and locking, etc. The following results noted: 1. The arthrographic findings of 22 TMJ were analyzed. a) Normal: 6 cases b) Anterior disc displacement with rediction: 6 cases · Early reduction: 2 cases · Intermediate reduction: 3 cases · Late reduction: 1 case c) Anterior disc displacement without reduction: 6 cases · Two cases had adhesion between the posterior portion of disc and the posterior surfaces of the articular eminence. 2. Among 22 cases, the clinical findings of 16 cases (73%) were compatible with arthrographic findings. 6 cases showed disparity between them.

  10. Sacroiliac joint: A review

    Directory of Open Access Journals (Sweden)

    Khushali Tilvawala

    2018-01-01

    Full Text Available Sacroiliac joint (SIJ pain is one of the common but underdiagnosed source of mechanical low back pain. The incidence is estimated to be in the range of 15%–30% in patients with nonradicular low back pain. The signs and symptoms of SIJ pain mimic pain arising from other causes of low back pain. There is no single symptom or physical examination finding that can firmly diagnose SIJ as a source of patient's pain. There is good evidence suggesting that a combination of three or more positive provocative tests strongly suggests SIJ dysfunction. Intra-articular injection with local anesthetic is considered the gold standard for diagnosis of SIJ pain. Many treatment modalities are available for SIJ pain, ranging from conservative management to surgical interventions. This review article covers all the aspects of SIJ pain, with treatment section mainly covering evidence-based interventional procedures.

  11. Theoretical analysis of rolled joints

    International Nuclear Information System (INIS)

    Sinha, R.K.

    1975-01-01

    A procedure for theoretically analysing the case of an externally restrained sandwich joint formed by a hypothetical uniform hydrostatic expansion process is outlined. Reference is made to a computer program based on this theory. Results illustrating the effect of major joint variables on residual contact pressure are presented and analysed. The applicability and limitations of this theory are discussed. (author)

  12. Arthroscopy of the ankle joint

    NARCIS (Netherlands)

    van Dijk, C. N.; Scholte, D.

    1997-01-01

    Ankle arthroscopy has become a standard procedure for a variety of indications. Joint distraction is applied by many authors. A recent retrospective multicentre study provoked the following questions. Is there an indication for diagnostic arthroscopy? Can arthroscopic surgery of the ankle joint be

  13. From joint to single audits

    DEFF Research Database (Denmark)

    Holm, Claus; Thinggaard, Frank

    2018-01-01

    This study analyses audit quality differences between audits by a single big audit firm and joint audits with either one or two big audit firms. We exploit the unique situation in Denmark beginning on 1 January 2005, at which time a long-standing mandatory joint audit system for listed companies ...

  14. A comparative study of matrix metalloproteinase and aggrecanase mediated release of latent cytokines at arthritic joints.

    Science.gov (United States)

    Mullen, Lisa; Adams, Gill; Foster, Julie; Vessillier, Sandrine; Köster, Mario; Hauser, Hansjörg; Layward, Lorna; Gould, David; Chernajovsky, Yuti

    2014-09-01

    Latent cytokines are engineered by fusing the latency associated peptide (LAP) derived from transforming growth factor-β (TGF-β) with the therapeutic cytokine, in this case interferon-β (IFN-β), via an inflammation-specific matrix metalloproteinase (MMP) cleavage site. To demonstrate latency and specific delivery in vivo and to compare therapeutic efficacy of aggrecanase-mediated release of latent IFN-β in arthritic joints to the original MMP-specific release. Recombinant fusion proteins with MMP, aggrecanase or devoid of cleavage site were expressed in CHO cells, purified and characterised in vitro by Western blotting and anti-viral protection assays. Therapeutic efficacy and half-life were assessed in vivo using the mouse collagen-induced arthritis model (CIA) of rheumatoid arthritis and a model of acute paw inflammation, respectively. Transgenic mice with an IFN-regulated luciferase gene were used to assess latency in vivo and targeted delivery to sites of disease. Efficient localised delivery of IFN-β to inflamed paws, with low levels of systemic delivery, was demonstrated in transgenic mice using latent IFN-β. Engineering of latent IFN-β with an aggrecanase-sensitive cleavage site resulted in efficient cleavage by ADAMTS-4, ADAMTS-5 and synovial fluid from arthritic patients, with an extended half-life similar to the MMP-specific molecule and greater therapeutic efficacy in the CIA model. Latent cytokines require cleavage in vivo for therapeutic efficacy, and they are delivered in a dose dependent fashion only to arthritic joints. The aggrecanase-specific cleavage site is a viable alternative to the MMP cleavage site for the targeting of latent cytokines to arthritic joints. 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.

  15. Transition joints in INDUS-2

    International Nuclear Information System (INIS)

    Sridhar, R.; Amalraj, William; Shukla, S.K.; Jain, A.K.

    2003-01-01

    Full text: A large number of welding joints are being employed in the fabrication of Indus-2 synchrotron storage ring being constructed at CAT. Apart from the TIG welded joints of aluminium alloy vacuum chambers, there are many other joints which are made between dissimilar metals. Stainless steel pipes are friction welded with aluminium pipes and are to be used as pumping ducts between vacuum pumps and the vacuum chambers. Similarly stainless steel flanges are fastened with aluminium flanges through a diamond seal. These joints are tested for a leak tightness of 2 x 10 -10 torr lit/sec of helium. This paper describes the details of the friction welded joints and their application in the Indus-2 synchrotron storage ring

  16. Induction brazing of complex joints

    DEFF Research Database (Denmark)

    Henningsen, Poul; Zhang, Wenqi; Bay, Niels

    2003-01-01

    , or if the hottest area is located outside the joint interface, a number of defects may appear: the braze metal may flow away from the joint, the flux may burn off, poor binding of the braze metal may appear or the braze metal may be overheated. Joint geometry as well as electro-magnetic properties of the work piece...... presents a combined numerical and experimental method for fast determination of appropriate coil geometry and position in induction brazing tube-to-plate joints of different ratios between tube and plate thickness and different combinations of the materials stainless steel, brass and copper. The method has...... proven to give successful results in brazing tube-plate joints of copper-brass, copper-stainless steel, stainless steel-brass, and stainless steel-stainless steel....

  17. Space Station alpha joint bearing

    Science.gov (United States)

    Everman, Michael R.; Jones, P. Alan; Spencer, Porter A.

    1987-01-01

    Perhaps the most critical structural system aboard the Space Station is the Solar Alpha Rotary Joint which helps align the power generation system with the sun. The joint must provide structural support and controlled rotation to the outboard transverse booms as well as power and data transfer across the joint. The Solar Alpha Rotary Joint is composed of two transition sections and an integral, large diameter bearing. Alpha joint bearing design presents a particularly interesting problem because of its large size and need for high reliability, stiffness, and on orbit maintability. The discrete roller bearing developed is a novel refinement to cam follower technology. It offers thermal compensation and ease of on-orbit maintenance that are not found in conventional rolling element bearings. How the bearing design evolved is summarized. Driving requirements are reviewed, alternative concepts assessed, and the selected design is described.

  18. Fatigue damage assessment of high-usage in-service aircraft fuselage structure

    Science.gov (United States)

    Mosinyi, Bao Rasebolai

    As the commercial and military aircraft fleets continue to age, there is a growing concern that multiple-site damage (MSD) can compromise structural integrity. Multiple site damage is the simultaneous occurrence of many small cracks at independent structural locations, and is the natural result of fatigue, corrosion, fretting and other possible damage mechanisms. These MSD cracks may linkup and form a fatigue lead crack of critical length. The presence of MSD also reduces the structure's ability to withstand longer cracks. The objective of the current study is to assess, both experimentally and analytically, MSD formation and growth in the lap joint of curved panels removed from a retired aircraft. A Boeing 727-232 airplane owned and operated by Delta Air Lines, and retired at its design service goal, was selected for the study. Two panels removed from the left-hand side of the fuselage crown, near stringer 4L, were subjected to extended fatigue testing using the Full-Scale Aircraft Structural Test Evaluation and Research (FASTER) facility located at the Federal Aviation Administration (FAA) William J. Hughes Technical Center. The state of MSD was continuously assessed using several nondestructive inspection (NDI) methods. Damage to the load attachment points of the first panel resulted in termination of the fatigue test at 43,500 fatigue cycles, before cracks had developed in the lap joint. The fatigue test for the second panel was initially conducted under simulated in-service loading conditions for 120,000 cycles, and no cracks were detected in the skin of the panel test section. Artificial damage was then introduced into the panel at selected rivets in the critical (lower) rivet row, and the fatigue loads were increased. Visually detectable crack growth from the artificial notches was first seen after 133,000 cycles. The resulting lead crack grew along the lower rivet row, eventually forming an 11.8" long unstable crack after 141,771 cycles, at which point the

  19. Joint action aesthetics.

    Science.gov (United States)

    Vicary, Staci; Sperling, Matthias; von Zimmermann, Jorina; Richardson, Daniel C; Orgs, Guido

    2017-01-01

    Synchronized movement is a ubiquitous feature of dance and music performance. Much research into the evolutionary origins of these cultural practices has focused on why humans perform rather than watch or listen to dance and music. In this study, we show that movement synchrony among a group of performers predicts the aesthetic appreciation of live dance performances. We developed a choreography that continuously manipulated group synchronization using a defined movement vocabulary based on arm swinging, walking and running. The choreography was performed live to four audiences, as we continuously tracked the performers' movements, and the spectators' affective responses. We computed dynamic synchrony among performers using cross recurrence analysis of data from wrist accelerometers, and implicit measures of arousal from spectators' heart rates. Additionally, a subset of spectators provided continuous ratings of enjoyment and perceived synchrony using tablet computers. Granger causality analyses demonstrate predictive relationships between synchrony, enjoyment ratings and spectator arousal, if audiences form a collectively consistent positive or negative aesthetic evaluation. Controlling for the influence of overall movement acceleration and visual change, we show that dance communicates group coordination via coupled movement dynamics among a group of performers. Our findings are in line with an evolutionary function of dance-and perhaps all performing arts-in transmitting social signals between groups of people. Human movement is the common denominator of dance, music and theatre. Acknowledging the time-sensitive and immediate nature of the performer-spectator relationship, our study makes a significant step towards an aesthetics of joint actions in the performing arts.

  20. Joint seal in tank

    International Nuclear Information System (INIS)

    Colquhoun, J.; White, G.V.

    1981-01-01

    A seal for a joint or gap between edges of adjacent wall sections (e.g. of concrete) of a liquid-containing vessel, such as a nuclear reactor cooling pond, comprises a sheet metal strip having longitudinally-extending edge parts, secured to the respective vessel-section edges, and a central part which is longitudinally corrugated to provide sufficient flexibility to accommodate slight relative movements between the vessel-section edges (e.g. due to thermal expansions). The edges of the sheet metal of the strip are turned in so that the edge parts of the strip are formed as generally U-section channels. These accommodate longitudinally extending securing bars which are bolted to the vessel wall sections by bolts which pass through the bars, through the free-edged wall of the channel section and through a longitudinally extending resilient seal pad compressed between that wall of the channel section and the vessel wall section to which it is secured. The other wall of the channel section (integral with the corrugated central part of the strip) has access windows through which the bolts are inserted and tightened, the windows being then closed off in liquid-tight manner by welding closure caps over them. (author)

  1. Temporomandibular Joint Regenerative Medicine

    Directory of Open Access Journals (Sweden)

    Xavier Van Bellinghen

    2018-02-01

    Full Text Available The temporomandibular joint (TMJ is an articulation formed between the temporal bone and the mandibular condyle which is commonly affected. These affections are often so painful during fundamental oral activities that patients have lower quality of life. Limitations of therapeutics for severe TMJ diseases have led to increased interest in regenerative strategies combining stem cells, implantable scaffolds and well-targeting bioactive molecules. To succeed in functional and structural regeneration of TMJ is very challenging. Innovative strategies and biomaterials are absolutely crucial because TMJ can be considered as one of the most difficult tissues to regenerate due to its limited healing capacity, its unique histological and structural properties and the necessity for long-term prevention of its ossified or fibrous adhesions. The ideal approach for TMJ regeneration is a unique scaffold functionalized with an osteochondral molecular gradient containing a single stem cell population able to undergo osteogenic and chondrogenic differentiation such as BMSCs, ADSCs or DPSCs. The key for this complex regeneration is the functionalization with active molecules such as IGF-1, TGF-β1 or bFGF. This regeneration can be optimized by nano/micro-assisted functionalization and by spatiotemporal drug delivery systems orchestrating the 3D formation of TMJ tissues.

  2. The joint in psoriatic arthritis.

    Science.gov (United States)

    Mortezavi, Mahta; Thiele, Ralph; Ritchlin, Christopher

    2015-01-01

    Psoriatic arthritis (PsA), a chronic inflammatory joint disease associated with psoriasis, is notable for diversity in disease presentation, course and response to treatment. Equally varied are the types of musculoskeletal involvement which include peripheral and axial joint disease, dactylitis and enthesitis. In this review, we focus on the psoriatic joint and discuss pathways that underlie synovial, cartilage and bone inflammation and highlight key histopathologic features. The pivotal inflammatory mechanisms and pathobiology of PsA parallel findings in other forms of spondyloarthritis but are distinct from disease pathways described in rheumatoid synovitis and bone disease. The diagnosis of PsA from both a clinical and imaging perspective is also discussed.

  3. Prevalence of comorbidities and baseline characteristics of LAP-BAND AP® subjects in the Helping Evaluate Reduction in Obesity (HERO study.

    Directory of Open Access Journals (Sweden)

    Nancy Dreyer

    Full Text Available OBJECTIVE: To describe the baseline characteristics in patients who chose placement of a LAP-BAND AP® System (LBAP and participated in the Helping Evaluate Reduction in Obesity (HERO Study across regions. PATIENTS AND METHODS: HERO is a five-year, prospective, multicenter, international study of patients with LBAP placement between July 22, 2009 and January 31, 2011. In addition to baseline and peri-surgery clinical data, seven follow up visits are scheduled at 3, 6 and 12 months, and annually through year five. Data collection included family and medical history, clinical outcomes, laboratory data, health-related quality of life (HRQoL, productivity, healthcare resource utilization, and adverse events. RESULTS: LBAP were placed in 1106 enrolled patients; 56.6% from the US, 26.3% from Europe, 7.1% from Canada, and 10.0% from Australia. The majority were female (n = 877 (79.3% with a mean age of 43 years (s.d. = 11.4 and mean body mass index of 45.1 kg/m(2 (s.d. = 6.9. The most common comorbidities were hypertension (HTN (overall  = 42.9% and diabetes (overall 22.2%, with 27% from the US and 14% from Europe. Overall, less than 5% had a history of cardiovascular disease. The prevalence rates of HTN, diabetes and cardiovascular disease were significantly (p<0.001 higher in men than in women across all regions. Overall HRQoL also worsened with increasing BMI. CONCLUSIONS: The HERO study is the first large, multinational and long-term registry with the LBAP. This study will provide real-world outcomes data on LAGB that will help inform patient choice, clinician treatment strategies, and payer reimbursement decisions.

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

    Science.gov (United States)

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

    1983-01-01

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

  5. Joint action aesthetics.

    Directory of Open Access Journals (Sweden)

    Staci Vicary

    Full Text Available Synchronized movement is a ubiquitous feature of dance and music performance. Much research into the evolutionary origins of these cultural practices has focused on why humans perform rather than watch or listen to dance and music. In this study, we show that movement synchrony among a group of performers predicts the aesthetic appreciation of live dance performances. We developed a choreography that continuously manipulated group synchronization using a defined movement vocabulary based on arm swinging, walking and running. The choreography was performed live to four audiences, as we continuously tracked the performers' movements, and the spectators' affective responses. We computed dynamic synchrony among performers using cross recurrence analysis of data from wrist accelerometers, and implicit measures of arousal from spectators' heart rates. Additionally, a subset of spectators provided continuous ratings of enjoyment and perceived synchrony using tablet computers. Granger causality analyses demonstrate predictive relationships between synchrony, enjoyment ratings and spectator arousal, if audiences form a collectively consistent positive or negative aesthetic evaluation. Controlling for the influence of overall movement acceleration and visual change, we show that dance communicates group coordination via coupled movement dynamics among a group of performers. Our findings are in line with an evolutionary function of dance-and perhaps all performing arts-in transmitting social signals between groups of people. Human movement is the common denominator of dance, music and theatre. Acknowledging the time-sensitive and immediate nature of the performer-spectator relationship, our study makes a significant step towards an aesthetics of joint actions in the performing arts.

  6. Joint action aesthetics

    Science.gov (United States)

    Vicary, Staci; Sperling, Matthias; von Zimmermann, Jorina; Richardson, Daniel C.

    2017-01-01

    Synchronized movement is a ubiquitous feature of dance and music performance. Much research into the evolutionary origins of these cultural practices has focused on why humans perform rather than watch or listen to dance and music. In this study, we show that movement synchrony among a group of performers predicts the aesthetic appreciation of live dance performances. We developed a choreography that continuously manipulated group synchronization using a defined movement vocabulary based on arm swinging, walking and running. The choreography was performed live to four audiences, as we continuously tracked the performers’ movements, and the spectators’ affective responses. We computed dynamic synchrony among performers using cross recurrence analysis of data from wrist accelerometers, and implicit measures of arousal from spectators’ heart rates. Additionally, a subset of spectators provided continuous ratings of enjoyment and perceived synchrony using tablet computers. Granger causality analyses demonstrate predictive relationships between synchrony, enjoyment ratings and spectator arousal, if audiences form a collectively consistent positive or negative aesthetic evaluation. Controlling for the influence of overall movement acceleration and visual change, we show that dance communicates group coordination via coupled movement dynamics among a group of performers. Our findings are in line with an evolutionary function of dance–and perhaps all performing arts–in transmitting social signals between groups of people. Human movement is the common denominator of dance, music and theatre. Acknowledging the time-sensitive and immediate nature of the performer-spectator relationship, our study makes a significant step towards an aesthetics of joint actions in the performing arts. PMID:28742849

  7. Education: A Joint Transformation Enabler

    National Research Council Canada - National Science Library

    Alexander, Renita

    2003-01-01

    ... in an organization not known for its adaptability. Underlying the pursuit of transformational concepts necessary to respond to 21st century challenges is an emphasis on joint operations and doctrine...

  8. Finishing touch to joint venture

    CERN Multimedia

    2003-01-01

    "A new process for polishing titanium and its alloys has been announced following an agreement between Bripol (an Anopol/Delmet joint venture) of Birmingham and the European Organisation for Nuclear Reseach (CERN) in Geneva" (1 paragraph).

  9. MRI of the hip joint

    International Nuclear Information System (INIS)

    Czerny, C.; Noebauer-Huhmann, I.M.; Imhof, H.

    2005-01-01

    Magnetic resonance imaging (MRI) is performed to diagnose many pathologic conditions affecting the hip joint. Either conventional MRI (without contrast enhancement of the joint cavity) or MR arthrography is used to detect and most accurately differentiate hip joint pathologies. Conventional MRI is performed in cases of bone marrow edema, necrosis, arthrosis and especially the so-called ''activated arthrosis'', as well as in inflammatory and tumorous entities. MR arthography, which has only recently become available for use, is excellently suited for diagnosing lesions of the acetabular labrum, cartilage lesions, and free articular bodies. This article provides an overview about MRI characteristics and their accuracy of hip joint diseases and the impact on the therapeutic procedure. (orig.)

  10. Campus/Industry Joint Ventures.

    Science.gov (United States)

    McDonald, Eugene J.

    1985-01-01

    Opportunities for joint economic ventures of colleges and industry are discussed, and a variety of ventures undertaken by Duke University are outlined, including a health club, hotel, and office building. Tax and financing considerations are noted. (MSE)

  11. Engine mounts and structural joints

    Indian Academy of Sciences (India)

    mental studies are presented, and limitations of the passive device are briefly discussed. .... For the sake of simplifying formulations, several studies have used .... that the component mode synthesis methods work well when the joint stiffness is ...

  12. Practical aspects of joint implementation

    International Nuclear Information System (INIS)

    Michaelowa, A.

    1995-01-01

    Article 4, 2a of the UN Framework Convention on Climate Change states the possibility of joint policies of different countries to achieve national greenhouse gas reduction commitments (Joint Implementation). The cost of reducing greenhouse gas emissions can be reduced drastically if industrialized countries shift abatement activities to developing countries as marginal cost of reduction is much higher in the former countries. In this way economic efficiency of abatement measures can be raised to the point where marginal cost is equal all over the world. At the Conference of the Parties in Berlin in March 1995, criteria for Joint Implementation are to be established. The paper discusses possible forms of Joint Implementation and develops criteria

  13. Joint Logistics, Fact or Fiction?

    National Research Council Canada - National Science Library

    Carroll, Walton

    1998-01-01

    ...) and the evolution of Joint doctrine to meet these new demands. The focus of this examination remains at the strategic level and the ability of the Services to meet the logistical demands of the modern theater battlefield...

  14. Joint Performance and Planning System

    Data.gov (United States)

    US Agency for International Development — A joint State/USAID system hosted by State that integrates resource and performance information at the program level and enables more flexible and frequent entry of...

  15. Torsion testing of bed joints

    DEFF Research Database (Denmark)

    Hansen, Klavs Feilberg; Pedersen, Carsten Mørk

    2008-01-01

    This paper describes a simple test method for determining the torsion strength of a single bed joint between two bricks and presents results from testing using this test method. The setup for the torsion test is well defined, require minimal preparation of the test specimen and the test can...... be carried out directly in a normal testing machine. The torsion strength is believed to be the most important parameter in out-of-plane resistance of masonry walls subjected to bending about an axis perpendicular to the bed joints. The paper also contains a few test results from bending of small walls about...... an axis perpendicular to the bed joints, which indicate the close connection between these results and results from torsion tests. These characteristics make the torsion strength well suited to act as substitute parameter for the bending strength of masonry about an axis perpendicular to the bed joints....

  16. Management of Prosthetic Joint Infection.

    Science.gov (United States)

    Tande, Aaron J; Gomez-Urena, Eric O; Berbari, Elie F; Osmon, Douglas R

    2017-06-01

    Although uncommon, prosthetic joint infection is a devastating complication. This challenging condition requires a coordinated management approach to achieve good patient outcomes. This review details the general principles to consider when managing patients with prosthetic joint infection. The different medical/surgical treatment strategies and how to appropriately select a strategy are discussed. The data to support each strategy are presented, along with discussion of antimicrobial strategies in specific situations. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Joint probabilities and quantum cognition

    International Nuclear Information System (INIS)

    Acacio de Barros, J.

    2012-01-01

    In this paper we discuss the existence of joint probability distributions for quantumlike response computations in the brain. We do so by focusing on a contextual neural-oscillator model shown to reproduce the main features of behavioral stimulus-response theory. We then exhibit a simple example of contextual random variables not having a joint probability distribution, and describe how such variables can be obtained from neural oscillators, but not from a quantum observable algebra.

  18. Joint probabilities and quantum cognition

    Energy Technology Data Exchange (ETDEWEB)

    Acacio de Barros, J. [Liberal Studies, 1600 Holloway Ave., San Francisco State University, San Francisco, CA 94132 (United States)

    2012-12-18

    In this paper we discuss the existence of joint probability distributions for quantumlike response computations in the brain. We do so by focusing on a contextual neural-oscillator model shown to reproduce the main features of behavioral stimulus-response theory. We then exhibit a simple example of contextual random variables not having a joint probability distribution, and describe how such variables can be obtained from neural oscillators, but not from a quantum observable algebra.

  19. Continuum description for jointed media

    International Nuclear Information System (INIS)

    Thomas, R.K.

    1982-04-01

    A general three-dimensional continuum description is presented for a material containing regularly spaced and approximately parallel jointing planes within a representative elementary volume. Constitutive relationships are introduced for linear behavior of the base material and nonlinear normal and shear behavior across jointing planes. Furthermore, a fracture permeability tensor is calculated so that deformation induced alterations to the in-situ values can be measured. Examples for several strain-controlled loading paths are presented

  20. Value of knee joint arthrography

    International Nuclear Information System (INIS)

    Luzsa, Gyoergy; Kiss Toth, Peter

    1985-01-01

    On the basis of the literature and the analysis of 204 examinations, the method and clinical application of knee joint arthrography are reviewed. 50 out of the 54 operated cases were perfectly diagnosed. The double contrast knee joint arthrography can be applied to detect meniscus changes, popliteal cysts, synovial disorders and chondral defects. The effectiveness of arthrography and arthroscopy was compared and the introduction of the former in each county seat is suggested. (author)

  1. Microstructure and bonding mechanism of Al/Ti bonded joint using Al-10Si-1Mg filler metal

    International Nuclear Information System (INIS)

    Sohn, Woong H.; Bong, Ha H.; Hong, Soon H.

    2003-01-01

    The microstructures and liquid state diffusion bonding mechanism of cp-Ti to 1050 Al using an Al-10.0wt.%Si-1.0wt.%Mg filler metal with 100 μm in thickness have been investigated at 620 deg. C under 1x10 -4 Torr. The effects of bonding process parameters on microstructure of bonded joint have been analyzed by using an optical microscope, AES, scanning electron microscopy and EDS. The interfacial bond strength of Al/Ti bonded joints was measured by the single lap shear test. The results show that the bonding at the interface between Al and filler metal proceeds by wetting the Al with molten filler metal, and followed by removal of oxide layer on surface of Al. The interface between Al and filler metal moved during the isothermal solidification of filler metal by the diffusion of Si from filler metal into Al layer. The interface between Al and filler metal became curved in shape with increasing bonding time due to capillary force at grain boundaries. The bonding at the interface between Ti and filler metal proceeds by the formation of two different intermetallic compound layers, identified as Al 5 Si 12 Ti 7 and Al 12 Si 3 Ti 5 , followed by the growth of the intermetallic compound layers. The interfacial bond strength at Al/Ti joint increased with increasing bonding time up to 25 min at 620 deg. C. However, the interfacial bond strength of Al/Ti joint decreased after bonding time of 25 min at 620 deg. C due to formation of cavities in Al near Al/intermetallic interfaces

  2. Near DC eddy current measurement of aluminum multilayers using MR sensors and commodity low-cost computer technology

    Science.gov (United States)

    Perry, Alexander R.

    2002-06-01

    Low Frequency Eddy Current (EC) probes are capable of measurement from 5 MHz down to DC through the use of Magnetoresistive (MR) sensors. Choosing components with appropriate electrical specifications allows them to be matched to the power and impedance characteristics of standard computer connectors. This permits direct attachment of the probe to inexpensive computers, thereby eliminating external power supplies, amplifiers and modulators that have heretofore precluded very low system purchase prices. Such price reduction is key to increased market penetration in General Aviation maintenance and consequent reduction in recurring costs. This paper examines our computer software CANDETECT, which implements this approach and permits effective probe operation. Results are presented to show the intrinsic sensitivity of the software and demonstrate its practical performance when seeking cracks in the underside of a thick aluminum multilayer structure. The majority of the General Aviation light aircraft fleet uses rivets and screws to attach sheet aluminum skin to the airframe, resulting in similar multilayer lap joints.

  3. Branching miter joints : principles and artwork

    NARCIS (Netherlands)

    Verhoeff, T.; Verhoeff, K.; Hart, G.W.; Sarhangi, R.

    2010-01-01

    A miter joint connects two beams, typically of the same cross section, at an angle such that the longitudinal beam edges continue across the joint. When more than two beams meet in one point, like in a tree, we call this a branching joint. In a branching miter joint, the beams’ longitudinal edges

  4. 12 CFR 347.107 - Joint ventures.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Joint ventures. 347.107 Section 347.107 Banks... INTERNATIONAL BANKING § 347.107 Joint ventures. (a) Joint ventures. If a bank, directly or indirectly, acquires or holds an equity interest in a foreign organization that is a joint venture, and the bank or its...

  5. About the Joint Chiefs of Staff

    Science.gov (United States)

    Skip to main content (Press Enter). Toggle navigation Joint Chiefs of Staff Joint Chiefs of Staff Joint Chiefs of Staff Facebook Twitter YouTube Flickr Blog Instagram Search JCS: Search Search Search JCS: Search Home Media News Photos Videos Publications About The Joint Staff Chairman Vice Chairman

  6. Degenerative Joint Diseases and Neuroinflammation.

    Science.gov (United States)

    Fusco, Mariella; Skaper, Stephen D; Coaccioli, Stefano; Varrassi, Giustino; Paladini, Antonella

    2017-04-01

    Rheumatic and joint diseases, as exemplified by osteoarthritis and rheumatoid arthritis, are among the most widespread painful and disabling pathologies across the globe. Given the continuing rise in life expectancy, their prevalence is destined to grow. Osteoarthritis, a degenerative joint disease, is, in particular, on its way to becoming the fourth leading cause of disability worldwide by 2020, with the rising incidence of obesity in addition to age being important factors. It is estimated that 25% of osteoarthritic individuals are unable to perform daily activities. Accompanying osteoarthritis is rheumatoid arthritis, which is a chronic systemic disease that often causes pain and deformity. At least 50% of those affected are unable to remain gainfully employed within 10 years of disease onset. A growing body of evidence now points to inflammation, locally and more systemically, as a promoter of damage to joints and bones, as well as joint-related functional deficits. The pathogenesis underlying joint diseases remains unclear; however, it is currently believed that cross-talk between cartilage and subchondral bone-and loss of balance between these two structures in joint diseases-is a critical element. This view is amplified by the presence of mast cells, whose dysregulation is associated with alterations of junction structures (cartilage, bone, synovia, matrix, nerve endings, and blood vessels). In addition, persistent activation of mast cells facilitates the development of spinal neuroinflammation mediated through their interaction with microglia. Unfortunately, current treatment strategies for rheumatic and articular disease are symptomatic and do little to limit disease progression. Research now should be directed at therapeutic modalities that target osteoarticular structural elements and thereby delaying disease progression and joint replacement. © 2016 World Institute of Pain.

  7. Management of acromioclavicular joint injuries.

    Science.gov (United States)

    Li, Xinning; Ma, Richard; Bedi, Asheesh; Dines, David M; Altchek, David W; Dines, Joshua S

    2014-01-01

    Acromioclavicular joint injuries are among the most common shoulder girdle injuries in athletes and most commonly result from a direct force to the acromion with the arm in an adducted position. Acromioclavicular joint injuries often present with associated injuries to the glenohumeral joint, including an increased incidence of superior labrum anterior posterior (SLAP) tears that may warrant further evaluation and treatment. Anteroposterior stability of the acromioclavicular joint is conferred by the capsule and acromioclavicular ligaments, of which the posterior and superior ligaments are the strongest. Superior-inferior stability is maintained by the coracoclavicular (conoid and trapezoid) ligaments. Type-I or type-II acromioclavicular joint injuries have been treated with sling immobilization, early shoulder motion, and physical therapy, with favorable outcomes. Return to activity can occur when normal shoulder motion and strength are obtained and the shoulder is asymptomatic as compared with the contralateral normal extremity. The management of type-III injuries remains controversial and is individualized. While a return to the previous level of functional activity with nonsurgical treatment has been documented in a number of case series, surgical reduction and coracoclavicular ligament reconstruction has been associated with a favorable outcome and can be considered in patients who place high functional demands on their shoulders or in athletes who participate in overhead sports. Surgical management is indicated for high-grade (≥type IV) acromioclavicular joint injuries to achieve anatomic reduction of the acromioclavicular joint, reconstruction of the coracoclavicular ligaments, and repair of the deltotrapezial fascia. Outcomes after surgical reconstruction of the coracoclavicular ligaments have been satisfactory with regard to achieving pain relief and return to functional activities, but further improvements in the biomechanical strength of these

  8. [Classification and Treatment of Sacroiliac Joint Dislocation].

    Science.gov (United States)

    Tan, Zhen; Huang, Zhong; Li, Liang; Meng, Wei-Kun; Liu, Lei; Zhang, Hui; Wang, Guang-Lin; Huang, Fu-Guo

    2017-09-01

    To develop a renewed classification and treatment regimen for sacroiliac joint dislocation. According to the direction of dislocation of sacroiliac joint,combined iliac,sacral fractures,and fracture morphology,sacroiliac joint dislocation was classified into 4 types. Type Ⅰ (sacroiliac anterior dislocation): main fracture fragments of posterior iliac wing dislocated in front of sacroiliac joint. Type Ⅱ (sacroiliac posterior dislocation): main fracture fragments of posterior iliac wing dislocated in posterior of sacroiliac joint. Type Ⅲ (Crescent fracturedislocation of the sacroiliac joint): upward dislocation of posterior iliac wing with oblique fracture through posterior iliac wing. Type ⅢA: a large crescent fragment and dislocation comprises no more than onethird of sacroiliac joint,which is typically inferior. Type ⅢB: intermediatesize crescent fragment and dislocation comprises between one and twothirds of joint. Type ⅢC: a small crescent fragment where dislocation comprises most,but not the entire joint. Different treatment regimens were selected for different types of fractures. Treatment for type Ⅰ sacroiliac joint dislocation: anterior iliac fossa approach pry stripping reset; sacroiliac joint fixed with sacroiliac screw through percutaneous. Treatment for type Ⅱ sacroiliac joint dislocation: posterior sacroiliac joint posterior approach; sacroiliac joint fixed with sacroiliac screw under computer guidance. Treatment for type ⅢA and ⅢB sacroiliac joint dislocation: posterior sacroiliac joint approach; sacroiliac joint fixed with reconstruction plate. Treatment for type ⅢC sacroiliac joint dislocation: sacroiliac joint closed reduction; sacroiliac joint fixed with sacroiliac screw through percutaneous. Treatment for type Ⅳ sacroiliac joint dislocation: posterior approach; sacroiliac joint fixed with spinal pelvic fixation. Results of 24 to 72 months patient follow-up (mean 34.5 months): 100% survival,100% wound healing,and 100

  9. A Computer in Your Lap.

    Science.gov (United States)

    Byers, Joseph W.

    1991-01-01

    The most useful feature of laptop computers is portability, as one elementary school principal notes. IBM and Apple are not leaders in laptop technology. Tandy and Toshiba market relatively inexpensive models offering durability, reliable software, and sufficient memory space. (MLH)

  10. Erivajadustega laps tavakooli? / Kaja Plado

    Index Scriptorium Estoniae

    Plado, Kaja

    1997-01-01

    Tartu Õpetajate Seminari üliõpilaste poolt läbi viidud ankeedist, selgitamaks, kui palju on tavakoolis abi vajavaid lapsi, kuidas nad jaotuvad klassiti ja õppeainete kaupa ning missugune on õpetajate hoiak nende lastega töötamiseks

  11. The first lap in QCD

    International Nuclear Information System (INIS)

    Close, F.E.

    1980-07-01

    The idea that quantum chromodynamics is Nature's choice for the theory of quark interactions and that desirable phenomena, such as quark confinement, are consequences of it are considered. The lecture is presented under the headings: (1) Why do we believe that quarks have colour. (2) A rapid summary of the parton model in deep inelastic scattering. (3) Non Abelian theories: the vertices. (4) Hyperfine splitting of hadrons: more evidence for colour. (5) Renormalisation. (6) Alpha(Q 2 ). (7) The renormalisation group equations. (8) QCD, the renormalisation group equation and deep inelastic data. (9) Higher order corrections in QCD. (U.K.)

  12. Laps ja loodus / Patrik Grahn

    Index Scriptorium Estoniae

    Grahn, Patrik

    2009-01-01

    Looduses viibimise ja mängimise tähtsusest lapse arengus. Artiklis tuginetakse uurimustele looduse, parkide ja aedade erinevate omadustega tüüpidest, eelkooliõuede õuemängude kohtadest ning looduspiirkondade tähendusest laste tervisele, motoorikale ja keskendumisvõimele

  13. Rheumatoid arthritis affecting temporomandibular joint

    Directory of Open Access Journals (Sweden)

    Amandeep Sodhi

    2015-01-01

    Full Text Available Rheumatoid arthritis (RA is a chronic, systemic, autoimmune inflammatory disorder that is characterized by joint inflammation, erosive properties and symmetric multiple joint involvement. Temporomandibular joint (TMJ is very rare to be affected in the early phase of the disease, thus posing diagnostic challenges for the dentist. Conventional radiographs fail to show the early lesions due to its limitations. More recently cone-beam computed tomography (CBCT has been found to diagnose the early degenerative changes of TMJ and hence aid in the diagnosis of the lesions more accurately. Our case highlights the involvement of TMJ in RA and the role of advanced imaging (CBCT in diagnosing the bony changes in the early phase of the disease.

  14. Leaving a joint audit system

    DEFF Research Database (Denmark)

    Holm, Claus; Thinggaard, Frank

    2014-01-01

    determinants model and an audit fee change model and include interaction terms. Findings: The authors find short-term fee reductions in companies switching to single audits, but only where the former joint audit contained a dominant auditor. The authors argue that in this situation bargaining power is more...... with the auditors than in a equally shared joint audit, and that the auditors' incentives to offer an initial fee discount are bigger. Research limitations/implications: The number of observations is constrained by the small Danish capital market. Future research could take a more qualitative research approach......, to examine whether the use of a single audit firm rather than two has an effect on audit quality. The area calls for further theory development covering audit fee and audit quality in joint audit settings. Practical implications: Comapnies should consider their relationship with their auditors before...

  15. Joint US/German Conference

    CERN Document Server

    Gulledge, Thomas; Jones, Albert

    1993-01-01

    This proceedings volume contains selected and refereed contributions that were presented at the conference on "Recent Developments and New Perspectives of Operations Research in the Area of Production Planning and Control" in Hagen/Germany, 25. - 26. June 1992. This conference was organized with the cooperation of the FernuniversiHit Hagen and was jointly hosted by the "Deutsche Gesellschaft fur Operations Research (DGOR)" and the "Manufacturing Special Interest Group of the Operations Research Society of America (ORSA-SIGMA)". For the organization of the conference we received generous financial support from the sponsors listed at the end of this volume. We wish to express our appreciation to all supporters for their contributions. This conference was the successor of the JOInt ORSA/DGOR-conference in Gaithersburg/Maryland, USA, on the 30. and 31. July 1991. Both OR-societies committed themselves in 1989 to host joint conferences on special topics of interest from the field of operations research. This goal ...

  16. Evaluation of Rock Joint Coefficients

    Science.gov (United States)

    Audy, Ondřej; Ficker, Tomáš

    2017-10-01

    A computer method for evaluation of rock joint coefficients is described and several applications are presented. The method is based on two absolute numerical indicators that are formed by means of the Fourier replicas of rock joint profiles. The first indicator quantifies the vertical depth of profiles and the second indicator classifies wavy character of profiles. The absolute indicators have replaced the formerly used relative indicators that showed some artificial behavior in some cases. This contribution is focused on practical computations testing the functionality of the newly introduced indicators.

  17. [Divorce and joint physical custody].

    Science.gov (United States)

    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.

  18. What Determines Joint Venture Termination?

    DEFF Research Database (Denmark)

    Nielsen, Bo Bernhard

    2012-01-01

    Joint venture (JV) research continues to flourish as researchers seek to advance our understanding of why so many JVs fail. Cui and Kumar (this issue) take a contingency approach to explain how and why business relatedness may provide new insights as to what determines JV termination. This commen......Joint venture (JV) research continues to flourish as researchers seek to advance our understanding of why so many JVs fail. Cui and Kumar (this issue) take a contingency approach to explain how and why business relatedness may provide new insights as to what determines JV termination...

  19. Dual joint space arthrography in temporomandibular joint disorders: Comparison with single inferior joint space arthrography

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hyung Sik; Chang, Duk Soo; Lee, Kyung Soo; Kim, Woo Sun; Sung, Jung Ho; Jun, Young Hwan [Capital Armed Forces General Hospital, Seoul (Korea, Republic of)

    1989-02-15

    The temporomandibular joint(TMJ) is really a complex of two synovial space separated by fibrocartilaginous disc. Single inferior joint space arthrography is commonly performed for evaluation of TMJ disorders, which is known to be superior in demonstrating joint dynamics. But it reveals only the inferior surface of the disc. Therefore, dual space arthrography is superior to demonstrate the soft tissue anatomic feature of the joint such as disc position and shape. Authors performed 83 TMJ arthrograms in TMJ problems. Initially, the inferior joint space was done and then the superior space was sequentially contrasted. The follow results were noted: 1. In all cases, dual space arthrography revealed accurate disc shape and positions. 2. Concordant findings between the two techniques: 68 cases (82%). Discordance between the two techniques: 15 cases (18%) 3. Possible causes of discordance between inferior and dual space arthrography. a) Normal varians of anterior recess: 3 cases b) Posterior disc displacement: 4 cases c) Influence of the patient's head position change :4 cases d) False perforation: 2 cases e) Reduction change: 2 cases 4. In 5 cases with anterior displacement, dual space arthrography gave additional findings such as adhesion within the superior space, which could not be evaluated by single inferior space.

  20. Professionnalité des enseignants: vers une définition du collectif à partir d'une recherche au Lycée Autogéré de Paris (LAP

    Directory of Open Access Journals (Sweden)

    Maria Papantoniou

    2012-12-01

    Full Text Available Nous proposons de présenter dans cet article une partie des résultats de la recherche que nous avons effectuée au sein du Lycée Autogéré de Paris (LAP. Nos observations sont centrées sur le fonctionnement de ce lycée et ses incidences sur le rapport des élèves à l'école et aux disciplines scolaires. Nous avons été amenée à proposer le concept de Travail d'Institutionnalisation (TDI pour désigner la pratique d'autogestion au LAP qui consiste en un double travail: d'une part, sur les normes internes du lycée et, d'autre part, sur ses rapports aux institutions qui le traversent. Comment ce concept interroge-t-il la "violence" qui surgirait dans l'institution éducative et les pratiques des professionnels censées y répondre?