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Sample records for bonding and joining

  1. Mechanical joining and adhesive bonding - basics, technology, applications; Fuegen durch Umformen und Kleben - Grundlagen, Technologie, Anwendungen

    Energy Technology Data Exchange (ETDEWEB)

    Meschut, G. [Volkswagen AG, Konzern-Forschung, Wolfsburg (Germany)

    2001-07-01

    This contribution uses material combinations current in the automotive industry to demonstrate the mutual dependence of joining processes and their implications for the geometric shaping of fasteners in the combined shaping and adhesive bonding joining process. The mechanical properties of joints made using combined and elementary methods are compared taking into consideration quasi static, oscillating and impact-type loads, and ageing characteristics. The results demonstrate that the combination of mechanical and adhesive bonding methods produces joints of technologically high quality which can be implemented in optimised light-weight construction. General information is provided on the use of low-heat hybrid joining technology for project planning of this type of connections in industrial practice. (orig.) [German] Der Beitrag verdeutlicht anhand von aktuellen Werkstoffkombinationen aus dem Fahrzeugbau die gegenseitige Beeinflussung der Fuegeprozesse und die Folgen fuer die Fuegeelementausbildung bei der Verfahrenskombination Fuegen durch Umformen und Kleben. Die mechanischen Eigenschaften von kombiniert gefuegten und elementar gefuegten Verbindungen unter quasistatischer, schwingender und stossartiger Belastung sowie das Alterungsverhalten werden gegenuebergestellt. Die Ergebnisse zeigen, dass mittels der Kombination mechanischer Fuegeverfahren mit dem Kleben technologisch hochwertige Verbindungen fuer den eigenschaftsoptimierten Leichtbau realisierbar sind. Fuer die Projektierung derartiger Verbindungen in der industriellen Praxis werden allgemeingueltige Hinweise zum Einsatz der waermearmen Hybridfuegetechnik gegeben. (orig.)

  2. Mechanical joining and adhesive bonding. Joining processes with new challenges to materials testing; Umformen und Kleben. Fuegeverfahren mit neuen Herausforderungen fuer die Materialpruefung

    Energy Technology Data Exchange (ETDEWEB)

    Meschut, G. [Volkswagen AG, Wolfsburg (Germany)

    2002-07-01

    This contribution highlights new material combinations in the automotive industry to demonstrate the mutual dependence of joining processes and their implications for the geometric shaping of fasteners in the combined shaping and adhesive bonding joining process. The mechanical properties of joints produced by combined and elementary methods are compared taking into consideration quasi static, oscillating and impact-type loads, and ageing characteristics. The results demonstrate that the combination of mechanical and adhesive bonding methods produces joints of high technological quality which can be implemented in optimised light-weight construction. General information is provided on the use of low-heat hybrid joining technology for project planning of this type of connections in industrial practice. (orig.)

  3. Study of diffusion bonding of WL10 to SS joining with and without titanium interlayer using thermo mechanical simulator

    International Nuclear Information System (INIS)

    The sound joining of Tungsten alloy (W+1%LaO3) material with Stainless Steel material (SS316L) is demanded for He-cooled divertor for demo like Tokamak in near future application. The life of the divertor finger can be assessed by quality of the joining between two the materials. Due to significantly large difference of thermal mismatch, the joining of WL10 and SS material is appeared to be difficult one. The Helium cooled modular divertor is expected to face with the heat load of 10MW/m2 with operation temperature at W tile ∼ 1700°C and 700°C for WL10 to SS region (thimble). There are possible ways for joining of these two materials such as vacuum brazing route, diffusion bonding route etc. In this paper, diffusion bonding route was followed to prepare the joining of the WL10 material and SS material using Thermo mechanical simulator machine (Gleeble 3800). Diffusion bonding of WL10 and SS material has been carried out at various temperatures 800 °C, 850°C, 900 °C, 950 °C and 1000 °C with uniaxial pressure 5 MPa to 20 MPa with the hold time of 15 Min and 30 Min with and without titanium interlayer. The joint specimens have been investigated by NDT (UT by immersion probe), microstructural examination and hardness measurement. In this paper, the methodology for the preparation of diffusion bonding and the optimization of the diffusion bonding parameters for the joining of WL10 and SS material will be discussed. (author)

  4. Effect of joining temperature on the microstructure and strength of tungsten/ferritic steel joints diffusion bonded with a nickel interlayer

    OpenAIRE

    Zhong, Zhihong; Jung, Hun-chea; Hinoki, Tatsuya; KOHYAMA, Akira

    2010-01-01

    A diffusion bonding process, for joining of tungsten to ferritic steel using nickel as an interlayer, was developed for nuclear component application. The effect of joining temperature on the microstructure and tensile strength of the joint was investigated in this work. Metallographic analysis revealed that a good bonding was obtained at both the tungsten/nickel and nickel/steel interfaces, and the diffusion products were identified in the diffusion zone. Nano-indentation test across the joi...

  5. THE INVESTIGATION OF THE EFFECT ON THE JOINING OF TEMPERATURE AND PERIOD ON THE Cu-Ni INTERLAYER DIFFUSION BONDING OF Ti51Ni49COMPOSITE

    OpenAIRE

    KEJANLI, Haluk

    2009-01-01

    In this study, the effect on the joining of temperature and period on the Cu-Ni interlayers diffusion bonding of Ti51Ni49 composite was investigated. Diffusion bonding experiments were carried out in argon atmosphere at 910-940-970ºC temperatures and 5 MPa under a dynamic load for at 40 and 60 periods, using copper and nickel interlayer. The results of experiments, microstructure properties were examined by optic microscope, SEM and X-Ray analysis. The joining samples were carried out by shea...

  6. Study of mechanical joint strength of aluminum alloy 7075-T6 and dual phase steel 980 welded by friction bit joining and weld-bonding under corrosion medium

    International Nuclear Information System (INIS)

    Highlights: • Friction bit joining (FBJ) and weld-bonding (adhesive + FBJ) processes. • FBJ to spot weld high-strength Al alloy to high-strength steel. • Lap shear strength of ∼10 kN for high-strength Al alloy to high-strength steel. • Effective corrosion mitigation by combining FBJ with adhesive. - Abstract: In this work, we have employed a unique solid-sate joining process, called friction bit joining (FBJ), to spot weld aluminum alloy (AA) 7075-T6 and dual phase (DP) 980 steel. Static joint strength was studied in the lap shear tension configuration. In addition, weld-bonding (adhesive + FBJ) joints were studied in order to evaluate the ability of adhesive to mitigate the impact of corrosion on joint properties. Accelerated laboratory cyclic corrosion tests were carried out for both FBJ only and weld-bonding joints. The FBJ only joints that emerged from corrosion testing had lap shear failure loads that were significantly lower than freshly prepared joints. However, weld-bonding specimens retained more than 80% of the lap shear failure load of the freshly prepared weld-bonding specimens. Examination of joint cross sections confirmed that the presence of adhesive in the weld-bonding joints mitigated the effect of the corrosion environment, compared to FBJ only joints

  7. Microstructural and mechanical characterizations of steel tubes joined by transient liquid phase bonding using an amorphous Fe–B–Si interlayer

    Energy Technology Data Exchange (ETDEWEB)

    Di Luozzo, Nicolas, E-mail: nicolasdiluozzo@gmail.com [Laboratorio de Sólidos Amorfos, INTECIN, Facultad de Ingeniería, Universidad de Buenos Aires – CONICET, Paseo Colón 850, C1063ACV Buenos Aires (Argentina); Laboratoire des Matériaux et du Génie Physique (CNRS UMR 5628), Grenoble Institute of Technology, MINATEC, Grenoble Cedex 1 (France); Doisneau, Béatrice; Boudard, Michel [Laboratoire des Matériaux et du Génie Physique (CNRS UMR 5628), Grenoble Institute of Technology, MINATEC, Grenoble Cedex 1 (France); Fontana, Marcelo; Arcondo, Bibiana [Laboratorio de Sólidos Amorfos, INTECIN, Facultad de Ingeniería, Universidad de Buenos Aires – CONICET, Paseo Colón 850, C1063ACV Buenos Aires (Argentina)

    2014-12-05

    Highlights: • We joined steel tubes by means of TLPB process using a Fe–B–Si foil as interlayer. • We characterized both microstructure and mechanical properties of the joint. • The microstructure at the joint consists only of ferrite grains. • Evidences of non-epitaxial solidification were found. • Both tensile and hardness tests show the soundness of the joint. - Abstract: In this work the transient liquid phase bonding process was successfully used to join seamless carbon steel tubes using an amorphous Fe–B–Si foil as interlayer. The tubes were aligned with their butted surfaces in contact with the interlayer and the entire assembly was heated by means of an induction furnace under a reducing atmosphere. The temperature was raised to the process temperature (≈1300 °C) and then held for 7 min. The joining process was performed under a pressure of 5 MPa. The joined tubes microstructures were characterized by direct observations – scanning electron microscopy – and diffraction techniques – electron backscatter diffraction. Chemical analysis was performed by electron probe microanalysis. The joint region (JR) presents only ferrite grains - in contrast with the heat affected zone (HAZ) and the base metal (BM), whose microstructures consist of ferrite and cementite. Si content at the JR was precisely determined by chemical profiling, showing higher concentrations of Si compared with the HAZ and BM. These results are in accordance with the fact that the cementite is unable to form in Si enriched zones. Also, ferrite grains at the JR present high-angle grain boundaries with respect to the grains of the HAZ. Tensile tests show that the joined tubes failed away from the bond, at the HAZ, and reached 96% of the ultimate tensile strength of the BM, in the as-bonded condition. Microindentation hardness profiles across the bonding zone are in agreement with the observed microstructures at the different zones of the bond region.

  8. Microstructural and mechanical characterizations of steel tubes joined by transient liquid phase bonding using an amorphous Fe–B–Si interlayer

    International Nuclear Information System (INIS)

    Highlights: • We joined steel tubes by means of TLPB process using a Fe–B–Si foil as interlayer. • We characterized both microstructure and mechanical properties of the joint. • The microstructure at the joint consists only of ferrite grains. • Evidences of non-epitaxial solidification were found. • Both tensile and hardness tests show the soundness of the joint. - Abstract: In this work the transient liquid phase bonding process was successfully used to join seamless carbon steel tubes using an amorphous Fe–B–Si foil as interlayer. The tubes were aligned with their butted surfaces in contact with the interlayer and the entire assembly was heated by means of an induction furnace under a reducing atmosphere. The temperature was raised to the process temperature (≈1300 °C) and then held for 7 min. The joining process was performed under a pressure of 5 MPa. The joined tubes microstructures were characterized by direct observations – scanning electron microscopy – and diffraction techniques – electron backscatter diffraction. Chemical analysis was performed by electron probe microanalysis. The joint region (JR) presents only ferrite grains - in contrast with the heat affected zone (HAZ) and the base metal (BM), whose microstructures consist of ferrite and cementite. Si content at the JR was precisely determined by chemical profiling, showing higher concentrations of Si compared with the HAZ and BM. These results are in accordance with the fact that the cementite is unable to form in Si enriched zones. Also, ferrite grains at the JR present high-angle grain boundaries with respect to the grains of the HAZ. Tensile tests show that the joined tubes failed away from the bond, at the HAZ, and reached 96% of the ultimate tensile strength of the BM, in the as-bonded condition. Microindentation hardness profiles across the bonding zone are in agreement with the observed microstructures at the different zones of the bond region

  9. Joining of SiC Fiber-Bonded Ceramics using Silver, Copper, Nickel, Palladium, and Silicon-Based Alloy Interlayers

    Energy Technology Data Exchange (ETDEWEB)

    Asthana, Rajiv [University of Wisconsin-Stout, Menomonie; Singh, Mrityunjay [NASA-Glenn Research Center, Cleveland; Lin, Hua-Tay [ORNL; Matsunaga, Kenji [Ube Industries, Ltd.; Ishikawa, Toshihiro [Ube Industries, Ltd.

    2013-01-01

    SiC fiber-bonded ceramics, SA-Tyrannohex, (SA-THX) with perpendicular and parallel fiber orientations were brazed using Ag-, Ni- and Pd-base brazes, and four Si X (X: Ti, Cr, Y, Ta) eutectics. Outcomes were variable, ranging from bonded joints through partially bonded to un-bonded joints. Prominent Ti- and Si-rich interfaces developed with Cusil-ABA, Ticusil, and Copper-ABA and Ni- and Si-rich layers with MBF-20. Stress rupture tests at 650 and 750 C on Cusil-ABA-bonded joints revealed a temperature-dependent behavior for the perpendicular joints but not for the parallel joints with failure occurring at brazed interface. Higher-use temperatures can be targeted with eutectic Si Ti and Si Cr alloys.

  10. Welding and Joining of Titanium Aluminides

    Directory of Open Access Journals (Sweden)

    Jian Cao

    2014-06-01

    Full Text Available Welding and joining of titanium aluminides is the key to making them more attractive in industrial fields. The purpose of this review is to provide a comprehensive overview of recent progress in welding and joining of titanium aluminides, as well as to introduce current research and application. The possible methods available for titanium aluminides involve brazing, diffusion bonding, fusion welding, friction welding and reactive joining. Of the numerous methods, solid-state diffusion bonding and vacuum brazing have been most heavily investigated for producing reliable joints. The current state of understanding and development of every welding and joining method for titanium aluminides is addressed respectively. The focus is on the fundamental understanding of microstructure characteristics and processing–microstructure–property relationships in the welding and joining of titanium aluminides to themselves and to other materials.

  11. Structural Join and Staircase Join Algorithms of Sibling Relationship

    Institute of Scientific and Technical Information of China (English)

    Chang-Xuan Wan; Xi-Ping Liu

    2007-01-01

    The processing of XML queries can result in evaluation of various structural relationships. Efficient algorithms for evaluating ancestor-descendant and parent-child relationships have been proposed. Whereas the problems of evaluating preceding-sibling-following-sibling and preceding-following relationships are still open. In this paper, we studied the struc-tural join and staircase join for sibling relationship. First, the idea of how to filter out and minimize unnecessary reads of elements using parent's structural information is introduced, which can be used to accelerate structural joins of parent-child and preceding-sibling-following-sibling relationships. Second, two efficient structural join algorithms of sibling relationship are proposed. These algorithms lead to optimal join performance: nodes that do not participate in the join can be judged beforehand and then skipped using B+-tree index. Besides, each element list joined is scanned sequentially once at most.Furthermore, output of join results is sorted in document order. We also discussed the staircase join algorithm for sibling axes. Studies show that, staircase join for sibling axes is close to the structural join for sibling axes and shares the samecharacteristic of high efficiency. Our experimental results not only demonstrate the effectiveness of our optimizing techniquesfor sibling axes, but also validate the efficiency of our algorithms. As far as we know, this is the first work addressing thisproblem specially.

  12. Joints of magnesium to dissimilar metals - comperative study of soldering, adhesive bonding and mechanical joining; Magnesium-Mischverbindungen - Vergleichende Untersuchungen zwischen Loeten, Kleben und mechanischem Fuegen

    Energy Technology Data Exchange (ETDEWEB)

    Muecklich, S.; Wielage, B. [Technische Univ. Chemnitz (Germany); Horstmann, M.; Hahn, O. [Paderborn Univ. (Germany). Lehrstuhl fuer Werkstoff- und Fuegetechnik

    2007-07-01

    For joints of magnesium to dissimilar metals like aluminium or steel, the fundamentals and the state of knowledge concerning glueing, soldering, mechanical joining and hybrid methods are pointed out. (orig.)

  13. Machining, joining and modifications of advanced materials

    CERN Document Server

    Altenbach, Holm

    2016-01-01

    This book presents the latest advances in mechanical and materials engineering applied to the machining, joining and modification of modern engineering materials. The contributions cover the classical fields of casting, forming and injection moulding as representative manufacturing methods, whereas additive manufacturing methods (rapid prototyping and laser sintering) are treated as more innovative and recent technologies that are paving the way for the manufacturing of shapes and features that traditional methods are unable to deliver. The book also explores water jet cutting as an innovative cutting technology that avoids the heat build-up typical of classical mechanical cutting. It introduces readers to laser cutting as an alternative technology for the separation of materials, and to classical bonding and friction stir welding approaches in the context of joining technologies. In many cases, forming and machining technologies require additional post-treatment to achieve the required level of surface quali...

  14. Lightning Fast and Space Efficient Inequality Joins

    KAUST Repository

    Khayyat, Zuhair

    2015-09-01

    Inequality joins, which join relational tables on inequality conditions, are used in various applications. While there have been a wide range of optimization methods for joins in database systems, from algorithms such as sort-merge join and band join, to various indices such as B+-tree,R*-tree and Bitmap, inequality joins have received little attention and queries containing such joins are usually very slow. In this paper, we introduce fast inequality join algorithms. We put columns to be joined in sorted arrays and we use permutation arrays to encode positions of tuples in one sorted array w.r.t. the other sorted array. In contrast to sort-merge join, we use space effcient bit-arrays that enable optimizations, such as Bloom filter indices, for fast computation of the join results. We have implemented a centralized version of these algorithms on top of PostgreSQL, and a distributed version on top of Spark SQL. We have compared against well known optimization techniques for inequality joins and show that our solution is more scalable and several orders of magnitude faster.

  15. Lightning fast and space efficient inequality joins

    KAUST Repository

    Khayyat, Zuhair

    2015-09-01

    Inequality joins, which join relational tables on inequality conditions, are used in various applications. While there have been a wide range of optimization methods for joins in database systems, from algorithms such as sort-merge join and band join, to various indices such as B+-tree, R*-tree and Bitmap, inequality joins have received little attention and queries containing such joins are usually very slow. In this paper, we introduce fast inequality join algorithms. We put columns to be joined in sorted arrays and we use permutation arrays to encode positions of tuples in one sorted array w.r.t. the other sorted array. In contrast to sort-merge join, we use space efficient bit-arrays that enable optimizations, such as Bloom filter indices, for fast computation of the join results. We have implemented a centralized version of these algorithms on top of PostgreSQL, and a distributed version on top of Spark SQL. We have compared against well known optimization techniques for inequality joins and show that our solution is more scalable and several orders of magnitude faster.

  16. Comparison of joining techniques: soldering, adhesive bonding, mechanical joining of magnesium; Fuegeverfahren im Vergleich: Loeten, Kleben, Mechanisches Fuegen von Magnesium

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, O.; Horstmann, M. [Laboratorium fuer Werkstoff- und Fuegetechnik (LWF), Universitaet Paderborn (Germany); Wielage, B.; Muecklich, S. [Lehrstuhl fuer Verbundwerkstoffe, TU Chemnitz (Germany)

    2007-02-15

    Due to their light weight construction potential magnesium sheets are of increasing interest during recent years. During the production process appropriated joining technologies are necessary for sheets to obtain various knot, profile, and sheet structures. Thus studies to develop appropriated joining technologies are of high importance. (Abstract Copyright [2007], Wiley Periodicals, Inc.) [German] Aufgrund des hohen Leichtbaupotenzials ist das Interesse der Industrie an Magnesiumblech in den letzten Jahren deutlich gestiegen. Damit das Blechmaterial in geeigneter Weise in der Produkten verarbeitet werden kann, bedarf es auch entsprechender Fuegeverfahren, die eine Verbindung mit unterschiedlichsten Knoten-, Profil- und Blechstrukturen sicherstellen koennen. Demgemaess haben auch die Forschungsanstrengungen zur Entwicklung geeigneter Fuegeverfahren zugenommen. (Abstract Copyright [2007], Wiley Periodicals, Inc.)

  17. Ceramic joining

    Energy Technology Data Exchange (ETDEWEB)

    Loehman, R.E. [Sandia National Lab., Albuquerque, NM (United States)

    1996-04-01

    This paper describes the relation between reactions at ceramic-metal interfaces and the development of strong interfacial bonds in ceramic joining. Studies on a number of systems are described, including silicon nitrides, aluminium nitrides, mullite, and aluminium oxides. Joints can be weakened by stresses such as thermal expansion mismatch. Ceramic joining is used in a variety of applications such as solid oxide fuel cells.

  18. Microwave joining of SiC ceramics and composites

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, I.; Silberglitt, R.; Tian, Y.L. [FM Technologies, Inc., Fairfax, VA (United States); Katz, J.D. [Los Alamos National Lab., NM (United States)

    1997-04-01

    Potential applications of SiC include components for advanced turbine engines, tube assemblies for radiant burners and petrochemical processing and heat exchangers for high efficiency electric power generation systems. Reliable methods for joining SiC are required in order to cost-effectively fabricate components for these applications from commercially available shapes and sizes. This manuscript reports the results of microwave joining experiments performed using two different types of SiC materials. The first were on reaction bonded SiC, and produced joints with fracture toughness equal to or greater than that of the base material over an extended range of joining temperatures. The second were on continuous fiber-reinforced SiC/SiC composite materials, which were successfully joined with a commercial active brazing alloy, as well as by using a polymer precursor.

  19. Laser-generated Macroscopic and Microscopic Surface Structures for the Joining of Aluminum and Thermoplastics using Friction Press Joining

    Science.gov (United States)

    Fuchs, Alexander N.; Wirth, Franz X.; Rinck, Philipp; Zaeh, Michael F.

    Structural lightweight construction is increasingly utilized in the aerospace and automotive industry. Hybrid structures have great potential, especially with regard to load-specific component layouts. Usually, a surface pre-treatment is applied prior to joining dissimilar materials to improve bonding mechanisms such as form closure. In previous studies pulsed wave (pw) lasers were used for structuring metals. This paper presents the results of aluminum pre-treatment via a continuous wave (cw) single-mode fiber laser: macroscopic and microscopic structures were generated on the aluminum surface; the samples were joined with glass fiber reinforced polyamide using Friction Press Joining (FPJ), a method for joining metals and thermoplastic polymers in lap joint configuration. Using these new methods for surface structuring, shear strength was increased by 40% compared to previous studies with pw lasers.

  20. High Temperature Joining and Characterization of Joint Properties in Silicon Carbide-Based Composite Materials

    Science.gov (United States)

    Halbig, Michael C.; Singh, Mrityunjay

    2015-01-01

    Advanced silicon carbide-based ceramics and composites are being developed for a wide variety of high temperature extreme environment applications. Robust high temperature joining and integration technologies are enabling for the fabrication and manufacturing of large and complex shaped components. The development of a new joining approach called SET (Single-step Elevated Temperature) joining will be described along with the overview of previously developed joining approaches including high temperature brazing, ARCJoinT (Affordable, Robust Ceramic Joining Technology), diffusion bonding, and REABOND (Refractory Eutectic Assisted Bonding). Unlike other approaches, SET joining does not have any lower temperature phases and will therefore have a use temperature above 1315C. Optimization of the composition for full conversion to silicon carbide will be discussed. The goal is to find a composition with no remaining carbon or free silicon. Green tape interlayers were developed for joining. Microstructural analysis and preliminary mechanical tests of the joints will be presented.

  1. Joining of advanced materials

    CERN Document Server

    Messler, Robert W

    1993-01-01

    Provides an unusually complete and readable compilation of the primary and secondary options for joining conventional materials in non-conventional ways. Provides unique coverage of adhesive bonding using both organic and inorganic adhesives, cements and mortars. Focuses on materials issues without ignoring issues related to joint design, production processing, quality assurance, process economics, and joining performance in service.Joining of advanced materials is a unique treatment of joining of both conventional and advanced metals andalloys, intermetallics, ceramics, glasses, polymers, a

  2. International Symposium on Interfacial Joining and Surface Technology (IJST2013)

    Science.gov (United States)

    Takahashi, Yasuo

    2014-08-01

    Interfacial joining (bonding) is a widely accepted welding process and one of the environmentally benign technologies used in industrial production. As the bonding temperature is lower than the melting point of the parent materials, melting of the latter is kept to a minimum. The process can be based on diffusion bonding, pressure welding, friction welding, ultrasonic bonding, or brazing-soldering, all of which offer many advantages over fusion welding. In addition, surface technologies such as surface modification, spraying, coating, plating, and thin-film formation are necessary for advanced manufacturing, fabrication, and electronics packaging. Together, interfacial joining and surface technology (IJST) will continue to be used in various industrial fields because IJST is a very significant form of environmentally conscious materials processing. The international symposium of IJST 2013 was held at Icho Kaikan, Osaka University, Japan from 27-29 November, 2013. A total of 138 participants came from around the world to attend 56 oral presentations and 36 posters presented at the symposium, and to discuss the latest research and developments on interfacial joining and surface technologies. This symposium was also held to commemorate the 30th anniversary of the Technical Commission on Interfacial Joining of the Japan Welding Society. On behalf of the chair of the symposium, it is my great pleasure to present this volume of IOP Conference Series: Materials Science and Engineering (MSE). Among the presentations, 43 papers are published here, and I believe all of the papers have provided the welding community with much useful information. I would like to thank the authors for their enthusiastic and excellent contributions. Finally, I would like to thank all members of the committees, secretariats, participants, and everyone who contributed to this symposium through their support and invaluable effort for the success of IJST 2013. Yasuo Takahashi Chair of IJST 2013

  3. Transient-Liquid-Phase and Liquid-Film-Assisted Joining ofCeramics

    Energy Technology Data Exchange (ETDEWEB)

    Sugar, Joshua D.; McKeown, Joseph T.; Akashi, Takaya; Hong, SungM.; Nakashima, Kunihiko; Glaeser, Andreas M.

    2005-02-09

    Two joining methods, transient-liquid-phase (TLP) joining and liquid-film-assisted joining (LFAJ), have been used to bond alumina ceramics. Both methods rely on multilayer metallic interlayers designed to form thin liquid films at reduced temperatures. The liquid films either disappear by interdiffusion (TLP) or promote ceramic/metal interface formation and concurrent dewetting of the liquid film (LFAJ). Progress on extending the TLP method to lower temperatures by combining low-melting-point (<450 C) liquids and commercial reactive-metal brazes is described. Recent LFAJ work on joining alumina to niobium using copper films is presented.

  4. Progress in Joining Ceramics to Metals

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The research and development of joining methods of ceramics to metals, especially brazing, diffusion bonding and partial transition liquid phase bonding, were introduced. Some opinions were put forward. For new composites emerging, it is necessary to develop new joining methods, particularly in the field of high temperature technique for joining ceramics to superalloys.

  5. Possibilities of joining techniques application at railway lines joining and maintenance

    Directory of Open Access Journals (Sweden)

    I. Samardžić

    2011-10-01

    Full Text Available This paper presents most important techniques which is possible to apply at joining of railway lines as well as maintenance procedure. Beside thermit welding as a older joint process for that job (since 1895. it is mentioned flash welding as a modern joining technique interesting from the point of cost efficiency. In a case of maintance tasks it is necessary to caunt arc welding processes and thermit welding, too. Authors gave some experimental date collected during investigation on railway lines joining techniques application.

  6. Joining and surfacing of advanced materials

    Institute of Scientific and Technical Information of China (English)

    Andrzej Kolasa; Wladyslaw Wlosinski

    2004-01-01

    The application of advanced materials, i.e. advanced ceramics, glasses, intermetallic phases and various type of composites, not only depends on their manufacture processes including a great input of know-how, but also on their abilities for processing, among which the joining processes play an important role. The uses of advanced materials are changing rapidly, with a major emphasis on technical applications, especially the components of machines, apparatus and technical devices expected to withstand very heavy exploitation conditions. Furthermore,these materials are becoming more complex, in terms of being strengthened and toughened by transformation processes as well as by the addition of other ceramic or metallic materials including nanomaterials. The successful use of advanced materials requires the development of equally advanced joining materials, processes and technology. Some selected examples of results of joining advanced materials with the use of various procedures as well as surface modification of structural components with the use of advanced materials obtained in the Welding Engineering Department of Warsaw University of Technology, Poland, are presented.

  7. Joining of dissimilar materials

    Science.gov (United States)

    Tucker, Michael C; Lau, Grace Y; Jacobson, Craig P

    2012-10-16

    A method of joining dissimilar materials having different ductility, involves two principal steps: Decoration of the more ductile material's surface with particles of a less ductile material to produce a composite; and, sinter-bonding the composite produced to a joining member of a less ductile material. The joining method is suitable for joining dissimilar materials that are chemically inert towards each other (e.g., metal and ceramic), while resulting in a strong bond with a sharp interface between the two materials. The joining materials may differ greatly in form or particle size. The method is applicable to various types of materials including ceramic, metal, glass, glass-ceramic, polymer, cermet, semiconductor, etc., and the materials can be in various geometrical forms, such as powders, fibers, or bulk bodies (foil, wire, plate, etc.). Composites and devices with a decorated/sintered interface are also provided.

  8. R and D of joining technology for SiC components with channel

    International Nuclear Information System (INIS)

    Full text of publication follows: Silicon carbide fiber reinforced silicon carbide matrix composites (SiC/SiC) are attractive structural material for high-temperature components as advanced energy system because of their excellent thermo-mechanical and low activation properties. Nevertheless, there are some critical issues connected to the size and complex shapes of the component for practical use because of machining difficulties. The solution to this problem is to use joining to build up large or complex shapes from a series of smaller and simply shaped components. Joining of SiC/SiC has been demonstrated using various techniques including diffusion bonding, brazing bonding and hot pressing with sinterable SiC powder. Development of reliable and simple joining method for SiC/SiC composites that satisfies the requirements of mechanical integrity, thermal properties and safety during operation and maintenance or accident is strongly required. In this study, joining methods with SiC powder as the joining adhesives were studied in order to avoid the residual stresses coming from CTE (Coefficient of Thermal Expansion) mismatch between substrate and joining layer. The mechanical strength and microstructure of joining material between SiC substrates are investigated. It has been also examined to produce SiC component with channel by using joining technique like powder sintering and diffusion bonding. The commercial Hexoloy-SA (Saint-Gobain Ceramics, USA) used in this work as substrate material. The fine β-SiC nano-powder which the average particle size is below 30 nm, Al2O3, Y2O3, and SiO2 were used as joining adhesives. The specimens were joined with 20 MPa and 1400-1900 deg. C by hot pressing in argon atmosphere. The tensile and shear tests were performed to investigate the bonding strength. The cross-section of the joint was characterized by using an optical microscope and scanning electron microscopy (SEM). The joining conditions for SiC component with channel were

  9. MICROWAVE JOINING OF ALUMINA CERAMIC AND HYDROXYLAPATITE BIOCERAMIC

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Microwave joining is a rapid developmental new techniqu e in recent years.This paper introduces a new microwave joining equipment which was made by our lab,succeeds in alumina ceramic-hydroxylapatite bioceramic j o in in the equipment, and analyzes the join situation of join boundary by using s canni ng electron microscope(SEM),this paper analyzes the mechanism of microwave joini ng also.

  10. Effects of Applied Load on 6061-T6 Aluminum Joined Employing a Novel Friction Bonding Process

    Science.gov (United States)

    Burkes, Douglas E.; Hallinan, Neil P.; Shropshire, Karen L.; Wells, Peter B.

    2008-12-01

    Friction bonding is under consideration for use in mass production of plate-type nuclear fuels for research reactors. This article discusses the effects of applied load (the most important process parameter for fabrication of these fuels) on temperature distribution, microstructure, and mechanical properties. Friction bonding experiments showed that tool geometry caused temperature gradients across the tool surface. Temperatures at the joint interface suggested the advancing side of the tool produced a majority of the frictional heat, while the retreating side of the tool mainly forged the plasticized material while bonding increased with applied load. The microstructure across the tool surface was also altered and, as a function of applied load, affected the mechanical properties. The 6061 aluminum alloy had mechanical properties close to a T4 temper after processing. Results documented in this article will aid in continual enhancement of friction bonding for nuclear fuel plate fabrication, and will hopefully contribute to continued advancement of friction stir welding (FSW) state of the art.

  11. Conjoint Forming - Technologies for Simultaneous Forming and Joining

    Science.gov (United States)

    Groche, P.; Wohletz, S.; Mann, A.; Krech, M.; Monnerjahn, V.

    2016-03-01

    The market demand for new products optimized for e. g. lightweight applications or smart components leads to new challenges in production engineering. Hybrid structures represent one promising approach. They aim at higher product performance by using a suitable combination of different materials. The developments of hybrid structures stimulate the research on joining of dissimilar materials. Since they allow for joining dissimilar materials without external heating technologies based on joining by plastic deformation seem to be of special attractiveness. The paper at hand discusses the conjoint forming approach. This approach combines forming and joining in one process. Two or more workpieces are joined while at least one workpiece is plastically deformed. After presenting the fundamental joining mechanisms, the conjoint forming approach is discussed comprehensively. Examples of conjoint processes demonstrate the effectiveness and reveal the underlying phenomena.

  12. Fabrication and Life Prediction of SSiC Ceramic Joint Joined with Silicon Resin YR3370

    Institute of Scientific and Technical Information of China (English)

    YUAN Xiao-kun; XU Bing-she

    2007-01-01

    Joints between sintered silicon carbide (SSiC) were produced using a polysiloxane silicon resin YR3370 (GE Toshiba Silicones) as joining material. Samples were heat treated in a 99.99% nitrogen flux at temperatures ranging from 1 100 ℃ to 1 300 ℃. Three point bending strength of the joint reached the maximum of 179 MPa as joined at 1 200 ℃. The joining layer is continuous, homogeneous and densified and has a thickness of 2 tm -5 μm. The joining mechanism is that the amorphous silicon oxycarbide (SixOyCz) ceramic pyrolyzed from silicon resin YR3370 acts as an inorganic adhesive to SSiC substrate, which means the formation of the continuous Si-C bond structure between SixOyCz structure and SSiC substrate. Life prediction of the ceramic joint can be realized through the measurement of the critical time of the joint after the cyclic loading test.

  13. Radiation-tolerant joining technologies for silicon carbide ceramics and composites

    Energy Technology Data Exchange (ETDEWEB)

    Katoh, Yutai, E-mail: katohy@ornl.gov [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831 (United States); Snead, Lance L.; Cheng, Ting; Shih, Chunghao; Lewis, W. Daniel [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, Tennessee 37831 (United States); Koyanagi, Takaaki; Hinoki, Tatsuya [Institute of Advanced Energy, Kyoto University, Uji, Kyoto 611-0011 (Japan); Henager, Charles H. [Pacific Northwest National Laboratory, 902 Battelle Blvd., Richland, WA 99352 (United States); Ferraris, Monica [Department of Applied Science and Technology, Politecnico di Torino, Corso Duca degli Abruzzi 24, I-10129 Torino (Italy)

    2014-05-01

    Silicon carbide (SiC) for nuclear structural applications, whether in the monolithic ceramic or composite form, will require a robust joining technology capable of withstanding the harsh nuclear environment. This paper presents significant progress made towards identifying and processing irradiation-tolerant joining methods for nuclear-grade SiC. In doing so, a standardized methodology for carrying out joint testing has been established consistent with the small volume samples mandated by neutron irradiation testing. Candidate joining technologies were limited to those that provide low induced radioactivity and included titanium diffusion bonding, Ti–Si–C MAX-phase joining, calcia–alumina glass–ceramic joining, and transient eutectic-phase SiC joining. Samples of these joints were irradiated in the Oak Ridge National Laboratory High Flux Isotope Reactor at 500 or 800 °C, and their microstructure and mechanical properties were compared to pre-irradiation conditions. Within the limitations of statistics, all joining methodologies presented retained their joint mechanical strength to ∼3 dpa at 500 °C, thus indicating the first results obtained on irradiation-stable SiC joints. Under the more aggressive irradiation conditions (800 °C, ∼5 dpa), some joint materials exhibited significant irradiation-induced microstructural evolution; however, the effect of irradiation on joint strength appeared rather limited.

  14. Radiation-tolerant joining technologies for silicon carbide ceramics and composites

    Energy Technology Data Exchange (ETDEWEB)

    Katoh, Yutai; Snead, Lance L.; Cheng, Ting; Shih, Chunghao; Lewis, W. Daniel; Koyanagi, Takaaki; Hinoki, Tatsuya; Henager, Charles H.; Ferraris, Monica

    2014-05-01

    Silicon carbide (SiC) for nuclear structural applications, whether in the monolithic ceramic or composite form, will require a robust joining technology capable of withstanding the harsh nuclear environment. This paper presents significant progress made towards identifying and processing irradiation-tolerant joining methods for nuclear-grade SiC. In doing so, a standardized methodology for carrying out joint testing has been established consistent with the small volume samples mandated by neutron irradiation testing. Candidate joining technologies were limited to those that provide low induced radioactivity and included titanium diffusion bonding, Ti–Si–C MAX-phase joining, calcia–alumina glass–ceramic joining, and transient eutectic-phase SiC joining. Samples of these joints were irradiated in the Oak Ridge National Laboratory High Flux Isotope Reactor at 500 or 800 °C, and their microstructure and mechanical properties were compared to pre-irradiation conditions. Within the limitations of statistics, all joining methodologies presented retained their joint mechanical strength to ~3 dpa at 500 °C, thus indicating the first results obtained on irradiation-stable SiC joints. Finally, under the more aggressive irradiation conditions (800 °C, ~5 dpa), some joint materials exhibited significant irradiation-induced microstructural evolution; however, the effect of irradiation on joint strength appeared rather limited.

  15. Adhesive bonding of stainless steel : strength and durability

    OpenAIRE

    Boyes, Robert

    1998-01-01

    Adhesive bonding as an alternative method of joining materials together has many advantages over the more conventional joining methods such as fusion and spot welding, bolting and riveting. For example, adhesives can be used to bond dissimilar materials, adhesive joints have a high stiffness to weight ratio and the stress distribution within the joint is much improved. Stainless steels are commonly used in applications that would clearly benefit from adhesive bonding; architectural cladding, ...

  16. Joining and fabrication techniques for high temperature structures including the first wall in fusion reactor

    International Nuclear Information System (INIS)

    The materials for PFC's (Plasma Facing Components) in a fusion reactor are severely irradiated with fusion products in facing the high temperature plasma during the operation. The refractory materials can be maintained their excellent properties in severe operating condition by lowering surface temperature by bonding them to the high thermal conducting materials of heat sink. Hence, the joining and bonding techniques between dissimilar materials is considered to be important in case of the fusion reactor or nuclear reactor which is operated at high temperature. The first wall in the fusion reactor is heated to approximately 1000 .deg. C and irradiated severely by the plasma. In ITER, beryllium is expected as the primary armour candidate for the PFC's; other candidates including W, Mo, SiC, B4C, C/C and Si3N4. Since the heat affected zones in the PFC's processed by conventional welding are reported to have embrittlement and degradation in the sever operation condition, both brazing and diffusion bonding are being considered as prime candidates for the joining technique. In this report, both the materials including ceramics and the fabrication techniques including joining technique between dissimilar materials for PFC's are described. The described joining technique between the refractory materials and the dissimilar materials may be applicable for the fusion reactor and Generation-4 future nuclear reactor which are operated at high temperature and high irradiation

  17. Joining and fabrication techniques for high temperature structures including the first wall in fusion reactor

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ho Jin; Lee, B. S.; Kim, K. B

    2003-09-01

    The materials for PFC's (Plasma Facing Components) in a fusion reactor are severely irradiated with fusion products in facing the high temperature plasma during the operation. The refractory materials can be maintained their excellent properties in severe operating condition by lowering surface temperature by bonding them to the high thermal conducting materials of heat sink. Hence, the joining and bonding techniques between dissimilar materials is considered to be important in case of the fusion reactor or nuclear reactor which is operated at high temperature. The first wall in the fusion reactor is heated to approximately 1000 .deg. C and irradiated severely by the plasma. In ITER, beryllium is expected as the primary armour candidate for the PFC's; other candidates including W, Mo, SiC, B4C, C/C and Si{sub 3}N{sub 4}. Since the heat affected zones in the PFC's processed by conventional welding are reported to have embrittlement and degradation in the sever operation condition, both brazing and diffusion bonding are being considered as prime candidates for the joining technique. In this report, both the materials including ceramics and the fabrication techniques including joining technique between dissimilar materials for PFC's are described. The described joining technique between the refractory materials and the dissimilar materials may be applicable for the fusion reactor and Generation-4 future nuclear reactor which are operated at high temperature and high irradiation.

  18. Fastening, coupling and joining technique between diaspora and irredenta

    Science.gov (United States)

    Bauer, C.-O.

    1980-06-01

    The problem of eliminating the present divergence and shattering (diaspora) in the treatment of problems of the fastening, coupling, and joining technique on different technical branches is examined. It is shown that by an appropriate independence the fastening, coupling and joining techniques can recognize and consequently utilize the numerous performance reserves which are concealed by the present organization and action due to the lack of systematically tended works.

  19. Joining of SiC ceramics and SiC/SiC composites

    Energy Technology Data Exchange (ETDEWEB)

    Rabin, B.H. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1995-08-01

    This project has successfully developed a practical and reliable method for fabricating SiC ceramic-ceramic joints. This joining method has the potential to facilitate the use of SiC-based ceramics in a variety of elevated temperature fossil energy applications. The technique is based on a reaction bonding approach that provides joint interlayers compatible with SiC, and excellent joint mechanical properties at temperatures exceeding 1000{degrees}C. Recent efforts have focused on transferring the joining technology to industry. Several industrial partners have been identified and collaborative research projects are in progress. Investigations are focusing on applying the joining method to sintered a-SiC and fiber-reinforced SiC/SiC composites for use in applications such as heat exchangers, radiant burners and gas turbine components.

  20. Method of joining ceramics

    Science.gov (United States)

    Henager, Jr., Charles H.; Brimhall, John L.

    2000-01-01

    According to the method of the present invention, joining a first bi-element carbide to a second bi-element carbide, has the steps of: (a) forming a bond agent containing a metal carbide and silicon; (b) placing the bond agent between the first and second bi-element carbides to form a pre-assembly; and (c) pressing and heating the pre-assembly in a non-oxidizing atmosphere to a temperature effective to induce a displacement reaction creating a metal silicon phase bonding the first and second bi-element carbides.

  1. Joins via Geometric Resolutions: Worst-case and Beyond

    OpenAIRE

    Khamis, Mahmoud Abo; Ngo, Hung Q.; Ré, Christopher; Rudra, Atri

    2014-01-01

    We present a simple geometric framework for the relational join. Using this framework, we design an algorithm that achieves the fractional hypertree-width bound, which generalizes classical and recent worst-case algorithmic results on computing joins. In addition, we use our framework and the same algorithm to show a series of what are colloquially known as beyond worst-case results. The framework allows us to prove results for data stored in Btrees, multidimensional data structures, and even...

  2. Combustion based technique for synthesis and joining of refractory materials

    Science.gov (United States)

    White, Jeremiah David Edward

    Gasless combustion systems offer features that make them attractive tools for a variety of potential applications. Among them are rapid heating rates, high exothermicity, and high maximum temperatures. These characteristics were exploited to accomplish three separate concepts including the joining of refractory materials, synthesis of a pore-free composite, and the study of thermal explosion in mechanically activated powders. Honeywell Aerospace is a leading producer of carbon brakes for commercial aircraft. The manufacturing process involves chemical vapor infiltration (CVI) to form a carbon matrix around a carbon fiber preform. A major disadvantage of this approach is the time required to form a fully dense preform, which is on the order of 140 days. In addition, after the brakes are in service, they have to be discarded while there is a relatively thick amount of friction material still available. There is a profit motive for reusing these discs which are out of spec. One such example would be to perform a refurbishment by bonding a new thin C/C element onto a used "core" to produce a brake that meets performance specifications. Unfortunately, joining C/C composites is not a simple task, as carbon does not lend itself to welding, and other means (e.g. mechanical or adhesives) would not hold up to the harsh operational conditions. A novel apparatus was designed, built, and proven to join C/C using so-called reactive resistance welding (RRW). It is shown that a joint stronger than the original material can be achieved using moderate electrical current and mechanical force. Additionally, joining layers of similar thickness and microstructure were obtained with different reactive media, ranging from pellets of pressed powders (˜1-2 mm) to thin metal foils (˜25 micron). By modifying the schematic of the RRW apparatus, porous C/C was infiltrated with liquid silicon in order to form a new pore-free C/C-SiC composite. It is shown that using such a process, the silicon

  3. Nanostructure evolution in joining of Al and Fe nanoparticles with femtosecond laser irradiation

    International Nuclear Information System (INIS)

    The joining of Al-Fe nanoparticles (NPs) by femtosecond (fs) laser irradiation is reported in this paper. Fe and Al NPs were deposited on a carbon film in vacuum via fs laser ablation. Particles were then exposed to multiple fs laser pulses at fluences between 0.5 and 1.3 mJ/cm2. Transmission Electron Microscopy (TEM) and Electron Diffraction X-ray observations indicate that Al and Fe NPs bond to each other under these conditions. For comparison, bonding of Al to Al and Fe to Fe NPs was also investigated. The nanostructure, as observed using TEM, showed that individual Al NPs were monocrystalline while individual Fe NPs were polycrystalline prior to joining and that these structures are retained after the formation of Al-Al and Fe-Fe NPs. Al-Fe NPs produced by fs laser joining exhibited a mixed amorphous and crystalline phase at the interface. Bonding is suggested to originate from intermixing within a region of high field intensity between particles

  4. Adhesive bonding of composite aircraft structures: Challenges and recent developments

    Science.gov (United States)

    Pantelakis, Sp.; Tserpes, K. I.

    2014-01-01

    In this review paper, the challenges and some recent developments of adhesive bonding technology in composite aircraft structures are discussed. The durability of bonded joints is defined and presented for parameters that may influence bonding quality. Presented is also, a numerical design approach for composite joining profiles used to realize adhesive bonding. It is shown that environmental ageing and pre-bond contamination of bonding surfaces may degrade significantly fracture toughness of bonded joints. Moreover, it is obvious that additional research is needed in order to design joining profiles that will enable load transfer through shearing of the bondline. These findings, together with the limited capabilities of existing non-destructive testing techniques, can partially explain the confined use of adhesive bonding in primary composite aircraft structural parts.

  5. Determinant and inverse of join matrices on two sets

    CERN Document Server

    Mattila, Mika

    2011-01-01

    Let $(P,\\preceq)$ be a lattice and $f$ a complex-valued function on $P$. We define meet and join matrices on two arbitrary subsets $X$ and $Y$ of $P$ by $(X,Y)_f=(f(x_i\\wedge y_j))$ and $[X,Y]_f=(f(x_i\\vee x_j))$ respectively. Here we present expressions for the determinant and the inverse of $[X,Y]_f$. Our main goal is to cover the case when $f$ is not semimultiplicative since the formulas presented earlier for $[X,Y]_f$ cannot be applied in this situation. In cases when $f$ is semimultiplicative we obtain several new and known formulas for the determinant and inverse of $(X,Y)_f$ and the usual meet and join matrices $(S)_f$ and $[S]_f$. We also apply these formulas to LCM, MAX, GCD and MIN matrices, which are special cases of join and meet matrices.

  6. An event history analysis of union joining and leaving.

    Science.gov (United States)

    Buttigieg, Donna M; Deery, Stephen J; Iverson, Roderick D

    2007-05-01

    This article examines parallel models of union joining and leaving using individual-level longitudinal panel data collected over a 5-year period. The authors utilized objective measures of joining and leaving collected from union and organizational records and took into account time by using event history analysis. The results indicated that union joining was negatively related to procedural justice and higher performance appraisals and positively related to partner socialization and extrinsic union instrumentality. Conversely, members were most likely to leave the union when they perceived lower procedural justice, where there was no union representative present in the workplace, and where they had individualistic orientations. The authors discuss the implications of these findings for theory and practice for trade unions. PMID:17484562

  7. Superplasticity and joining of zirconia-based ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez-Rodriguez, A.; Gutierrez-Mora, F.; Jimenez-Melendo, M.; Chaim, R.; Routbort, J. L.

    1999-12-10

    Steady-state creep and joining of alumina/zirconia composites containing alumina volume fractions of 20, 60, and 85% have been investigated between 1,250 and 1,350 C. Superplasticity of these compounds is controlled by grain-boundary sliding and the creep rate is a function of alumina volume fraction, not grain size. Using the principles of superplasticity, pieces of the composite have been joined by applying the stress required to achieve 5 to 10% strain to form a strong interface at temperatures as low as 1,200 C.

  8. How to join and participate in a medical corporation.

    Science.gov (United States)

    Thomas, C

    1986-09-01

    Some nurse practitioners are becoming shareholders of medical corporations. This article discusses preliminary plans and specific areas to consider before joining a medical corporation. Information is also presented on precautions that the NP should consider taking before becoming a shareholder in a medical corporation, and the benefits the NP can expect from such involvement. PMID:3763064

  9. Joining Uranium to Aluminum using Electron Beam Welding and an Explosively Clad Niobium Interlayer

    Energy Technology Data Exchange (ETDEWEB)

    Elmer, J W; Terrill, P; Brasher, D; Butler, D

    2001-06-12

    A uranium alloy was joined to a high strength aluminum alloy using a commercially pure niobium interlayer. Joining of the Nb interlayer to the aluminum alloy was performed using an explosive welding process, while joining the Nb interlayer to the uranium alloy was performed using an electron beam welding process. Explosive welding was selected to bond the Nb to the aluminum alloy in order to minimize the formation of brittle intermetallic phases. Electron beam welding was selected to join the Nb to the uranium alloy in order to precisely control melting so as to minimize mixing of the two metals. A Modified Faraday Cup (MFC) technique using computer-assisted tomography was employed to determine the power distribution of the electron beam so that the welding parameters could be directly transferred to other welding machines. Optical microscopy, scanning electron microscopy, microhardness, and tensile testing of the welds were used to characterize the resulting joints. This paper presents the welding techniques and processing parameters that were developed to produce high integrity ductile joints between these materials.

  10. Joining the RHIC Online and Offline Models

    CERN Document Server

    Malitsky, Nikolay; Fedotov, Alexei V; Kewisch, Jorg; Luccio, Alfredo U; Pilat, Fulvia Caterina; Ptitsyn, Vadim; Satogata, Todd; Talman, Richard M; Tepikian, Steven; Wei, Jie

    2005-01-01

    The paper presents an interface encompassing the RHIC online ramp model and the UAL offline simulation framework. The resulting consolidated facility aims to minimize the gap between design and operational data, and to facilitate analysis of RHIC performance and future upgrades in an operational context. The interface is based on the Accelerator Description Exchange Format (ADXF), and represents a snapshot of the RHIC online model which is in turn driven by machine setpoints. This approach is also considered as an intermediate step towards integrating the AGS and RHIC modeling environments to produce a unified online and offline AGS model for operations.

  11. Joining of SiC ceramics and SiC/SiC composites

    Energy Technology Data Exchange (ETDEWEB)

    Rabin, B.H. [Idaho National Engineering Lab., Idaho Falls, ID (United States)

    1996-08-01

    This project has successfully developed a practical and reliable method for fabricating SiC ceramic-ceramic joints. This joining method will permit the use of SiC-based ceramics in a variety of elevated temperature fossil energy applications. The technique is based on a reaction bonding approach that provides joint interlayers compatible with SiC, and excellent joint mechanical properties at temperatures exceeding 1000{degrees}C. Recent emphasis has been given to technology transfer activities, and several collaborative research efforts are in progress. Investigations are focusing on applying the joining method to sintered {alpha}-SiC and fiber-reinforced SiC/SiC composites for use in applications such as heat exchangers, radiant burners and gas turbine components.

  12. Joining the Ideational and the Interpersonal Metafunction

    DEFF Research Database (Denmark)

    Holsting, Alexandra

    2013-01-01

    a systemic functional point of view and to demonstrate how the systemic concepts of semantic domain and different linguistic metafunctions, in this case the ideational and the interpersonal, can shed new light on this field. Based on analyses of newspaper examples, it is demonstrated how the resources...

  13. Marie and Pierre Curie: joined in science

    International Nuclear Information System (INIS)

    This book relates the life and works of the most famous married couple of scientists. Their works have completely overturned the science of the 20. century and their discovery of radium was rewarded by the Nobel price in 1903. This marriage both in science and life ended three years later because of a banal accident: Pierre Curie is fatally knocked down by a horse carriage in Paris. (J.S.)

  14. Quantum theory and the lattice join

    International Nuclear Information System (INIS)

    An informal explanation is presented of Birkhoff's and von Neumann's proposal according to which it is necessary, due to quantum theory, to replace the well-known lattice of properties, which is a heritage from George Boole, by a new quantum lattice of properties mirroring the structure of the Hilbert space. (Z.S.). 4 figs., 12 refs

  15. Joining distributed complex objects: definition and performance

    NARCIS (Netherlands)

    Teeuw, Wouter B.; Blanken, Henk M.

    1992-01-01

    The performance of a non-standard distributed database system is strongly ifluenced by complex objects. The effective exploitation of parallelism in querying them and a suitable structure to store them are required in order to obtain acceptable response times in these database environments where per

  16. Recent progress in micro and nano-joining

    Science.gov (United States)

    Zhou, Y.; Hu, A.; Khan, M. I.; Wu, W.; Tam, B.; Yavuz, M.

    2009-05-01

    Micro and nano-joining has been identified as a key enabling technology in the construction of micromechanical and microelectronic devices. The current article reviews recent progress in micro and nano-joining. In particular, laser micro-welding (LMW) of crossed 316 LVM stainless steel (SS) wire was compared to conventional resistance micro-welding (RMW) and was successfully employed in welding a Pt-Ir /SS dissimilar combination. Welding of Au nanoparticles was realized using femtosecond laser irradiation and its application in the surface enhanced Raman spectroscopy was investigated. Brazing between carbon nanotube (CNT) bundles and Ni electrodes was attained in vacuum, resulting in the development of a novel CNT filament of incandescent lamps.

  17. Laser -Based Joining of Metallic and Non-metallic Materials

    Science.gov (United States)

    Padmanabham, G.; Shanmugarajan, B.

    Laser as a high intensity heat source can be effectively used for joining of materials by fusion welding and brazing in autogenous or in hybrid modes. In autogenous mode, welding is done in conduction , deep penetration , and keyhole mode. However, due to inherently high energy density available from a laser source, autogenous keyhole welding is the most popular laser welding mode. But, it has certain limitations like need for extremely good joint fit-up, formation of very hard welds in steel , keyhole instability, loss of alloying elements, etc. To overcome these limitations, innovative variants such as laser-arc hybrid welding , induction-assisted welding , dual beam welding , etc., have been developed. Using laser heat, brazing can be performed by melting a filler to fill the joints, without melting the base materials. Accomplishing laser-based joining as mentioned above requires appropriate choice of laser source, beam delivery system, processing head with appropriate optics and accessories. Basic principles of various laser-based joining processes, laser system technology, process parameters, metallurgical effects on different base materials, joint performance, and applications are explained in this chapter.

  18. Perfect state transfer, integral circulants and join of graphs

    CERN Document Server

    Angeles-Canul, Ricardo Javier; Opperman, Michael C; Paribello, Christopher C; Russell, Matthew C; Tamon, Christino

    2009-01-01

    We propose new families of graphs which exhibit quantum perfect state transfer. Our constructions are based on the join operator on graphs, its circulant generalizations, and the Cartesian product of graphs. We build upon the results of Ba\\v{s}i\\'{c} et al \\cite{bps09,bp09} and construct new integral circulants and regular graphs with perfect state transfer. More specifically, we show that the integral circulant $\\textsc{ICG}_{n}(\\{2,n/2^{b}\\} \\cup Q)$ has perfect state transfer, where $b \\in \\{1,2\\}$, $n$ is a multiple of 16 and $Q$ is a subset of the odd divisors of $n$. Using the standard join of graphs, we also show a family of double-cone graphs which are non-periodic but exhibit perfect state transfer. This class of graphs is constructed by simply taking the join of the empty two-vertex graph with a specific class of regular graphs. This answers a question posed by Godsil \\cite{godsil08}.

  19. Bonding and Integration Technologies for Silicon Carbide Based Injector Components

    Science.gov (United States)

    Halbig, Michael C.; Singh, Mrityunjay

    2008-01-01

    Advanced ceramic bonding and integration technologies play a critical role in the fabrication and application of silicon carbide based components for a number of aerospace and ground based applications. One such application is a lean direct injector for a turbine engine to achieve low NOx emissions. Ceramic to ceramic diffusion bonding and ceramic to metal brazing technologies are being developed for this injector application. For the diffusion bonding, titanium interlayers (PVD and foils) were used to aid in the joining of silicon carbide (SiC) substrates. The influence of such variables as surface finish, interlayer thickness (10, 20, and 50 microns), processing time and temperature, and cooling rates were investigated. Microprobe analysis was used to identify the phases in the bonded region. For bonds that were not fully reacted an intermediate phase, Ti5Si3Cx, formed that is thermally incompatible in its thermal expansion and caused thermal stresses and cracking during the processing cool-down. Thinner titanium interlayers and/or longer processing times resulted in stable and compatible phases that did not contribute to microcracking and resulted in an optimized microstructure. Tensile tests on the joined materials resulted in strengths of 13-28 MPa depending on the SiC substrate material. Non-destructive evaluation using ultrasonic immersion showed well formed bonds. For the joining technology of brazing Kovar fuel tubes to silicon carbide, preliminary development of the joining approach has begun. Various technical issues and requirements for the injector application are addressed.

  20. Joining of silicon carbide/silicon carbide composites and dense silicon carbide using combustion reactions in the titanium-carbon-nickel system

    International Nuclear Information System (INIS)

    This paper reports on a ceramic joining technique that has been developed that utilizes an exothermic combustion reaction to simultaneously synthesize the joint interlayer material and to bond together the ceramic workpieces. The method has been used to join SiC ceramics using Ti-C-Ni powder mixtures that ignite below 1200 degrees C to form a TiC-Ni joining material. Thin layers of the powder reactants were prepared by tape casting, and joining was accomplished by heating in a hot-press to ignite the combustion reaction. during this process, localized exothermic heating of the joint region resulted in chemical interaction at the interface between the TiC-Ni and the SiC ceramic that contributed to bonding. Room-temperature four-point bending strengths of joints produced by this method have exceeded 100 MPa

  1. Thermoplastic Joining and Assembly of Bulk Metallic Glass Composites Through Capacitive Discharge

    Science.gov (United States)

    Hofmann, Douglas C. (Inventor); Roberts, Scott N. (Inventor); Kozachkov, Henry (Inventor); Demetriou, Marios D. (Inventor); Schramm, Joseph P. (Inventor); Johnson, William L. (Inventor)

    2015-01-01

    Systems and methods for joining BMG Composites are disclosed. Specifically, the joining of BMG Composites is implemented so as to preserve the amorphicity of their matrix phase and the microstructure of their particulate phase. Implementation of the joining method with respect to the construction of modular cellular structures that comprise BMG Composites is also discussed.

  2. Laser based metal and plastics joining for lightweight design

    Science.gov (United States)

    Kahmann, Max; Quentin, Ulf; Kirchhoff, Marc; Brockmann, Rüdiger; Löffler, Klaus

    2015-03-01

    One of the most important issues in automotive industry is lightweight design, especially since the CO2 emission of new cars has to be reduced by 2020. Plastic and fiber reinforced plastics (e.g. CFRP and GFRP) receive besides new manufacturing methods and the employment of high-strength steels or non-ferrous metals increasing interest. Especially the combination of different materials such as metals and plastics to single components exhausts the entire potential on weight reduction. This article presents an approach based on short laser pulses to join such dissimilar materials in industrial applications.

  3. New sandwichmaterials - production, forming, joining and corrosion behaviour; Neuartige Sandwichverbunde - Herstellung, Umformverhalten, Fuegen und Korrosionsverhalten

    Energy Technology Data Exchange (ETDEWEB)

    Palkowski, H.; Lange, G. [TU Clausthal, Institut fuer Metallurgie (IMET), Lehrstuhl fuer Werkstoffumformung, Robert-Koch-Strasse 42, 38678 Clausthal-Zellerfeld (Germany); Giese, P.; Wesling, V. [Technische Universitaet Clausthal, Institut fuer Schweisstechnik und Trennende Fertigungsverfahren (Germany); Spieler, S.; Goellner, J. [Otto-von-Guericke-Universitaet Magdeburg Institut fuer Werkstoff- und Fuegetechnik (Germany)

    2006-07-15

    New sandwich structures with sheet metal of CrNi-steel and core layer made of polypropylene were examined with regard to the processing and corrosion characteristics. Practicable solutions for bonding sandwich structures are represented with selected examples of bonding variants. Joining of the sandwich structures was carried out by laser welding and in form of hybrid junctions by adhesion and welding. It has to be taken into account that construction units are transformed before joining. The joint if possible does not lie in the transforming range if it is joined first. In the 3 roll bending test tubing elements up to a process-bound diameter of 70 mm were manufactured. As expected the corrosion resistance is affected negatively by the oxide scale due to welding at the fusion lines. The characteristics of the basic material were regained after removing the oxide scale. A sensitization to intergranular corrosion was not detected. With correct subsequent treatment the finished sandwich structures are sufficient for the appropriate requirements. (Abstract Copyright [2006], Wiley Periodicals, Inc.) [German] Neuartige Blechsandwichstrukturen aus hochlegiertem Chrom-Nickel-Stahl mit Kernschichten aus Polypropylen wurden hinsichtlich der Verarbeitungs- und Korrosionseigenschaften untersucht. Anhand einiger ausgewaehlter Beispiele von Fuegevarianten werden praktikable Loesungen fuer das Verbinden der Cr-Ni-Blechsandwichstrukturen dargestellt. Die Ausfuehrung der Verbindungen der Sandwichstrukturen untereinander erfolgte mittels Laserstrahlschweissen und in Form von Hybridverbindungen durch Kleben und Schweissen. Es ist zu beachten, dass Bauteile vor dem Fuegen umgeformt werden bzw. die Fuegestelle moeglichst nicht im Umformbereich liegt, wenn zuerst gefuegt wird. Im 3-Rollenbiegeversuch wurden Rohrelemente bis zu einem verfahrensbegrenzten Durchmesser von 70 mm gefertigt. - Erwartungsgemaess wirkten sich die infolge des Schweissens auf den Schmelzlinien befindlichen

  4. Joining of SiC-ceramics by means of boron carbide, silicon and carbon for high temperature applications

    International Nuclear Information System (INIS)

    The present work is a contribution to joining of SiC-Ceramics for high temperature applications. The aim was to develop a joining technique for Silicon Carbide ceramics by means of boron, carbon and silicon. The joint is created by the formation of a welding zone, which consists of SiC as it is the material to be joined. For this purpose are used the follow means: (a) sputtering layers of B4C, Si and C, (b) vacuum coatings of Si or Si foils and C, (c) powder mixtures of B4C, Si and C. The joints were examined at ceramographic cross sections of the bonding zone, by means of XRD, REM/EDAX, TEM and EPMA. The bond strength was determined in the 4-point bend test at room temperature and at 1370 C. It was found that a useable result can be obtained, if the temperature of the joining process exceeds the melting point of Si (1410 C). A high bending strength with a high Weibull modulus was achieved by using sputter layers. The powder mixtures provided a satisfactory bending strength with a low Weibull modulus. (orig.)

  5. Joining of Beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, A

    2006-02-01

    A handbook dealing with the many aspects of beryllium that would be important for the users of this metal is currently being prepared. With an introduction on the applications, advantages and limitations in the use of this metal the following topics will be discussed in this handbook: physical, thermal, and nuclear properties; extraction from the ores; purification and casting of ingots; production and types of beryllium powders; consolidation methods, grades, and properties; mechanical properties with emphasis on the various factors affecting these properties; forming and mechanical working; welding, brazing, bonding, and fastening; machining; powder deposition; corrosion; health aspects; and examples of production of components. This report consists of ''Section X--Joining'' from the handbook. The prefix X is maintained here for the figures, tables and references. In this section the different methods used for joining beryllium and the advantages, disadvantages and limitations of each are presented. The methods discussed are fusion welding, brazing, solid state bonding (diffusion bonding and deformation bonding), soldering, and mechanical fastening. Since beryllium has a high affinity for oxygen and nitrogen with the formation of oxides and nitrides, considerable care must be taken on heating the metal, to protect it from the ambient atmosphere. In addition, mating surfaces must be cleaned and joints must be designed to minimize residual stresses as well as locations for stress concentration (notch effects). In joining any two metals the danger exists of having galvanic corrosion if the part is subjected to moisture or to any type of corroding environment. This becomes a problem if the less noble (anodic) metal has a significantly smaller area than the more noble (cathodic) metal since the ions (positive charges) from the anodic (corroding) metal must correspond to the number of electrons (negative charges) involved at the cathode. Beryllium

  6. End Closure Joining of Ferritic-Martensitic and Oxide-Dispersion Strengthened Steel Cladding Tubes by Magnetic Pulse Welding

    Science.gov (United States)

    Lee, Jung-Gu; Park, Jin-Ju; Lee, Min-Ku; Rhee, Chang-Kyu; Kim, Tae-Kyu; Spirin, Alexey; Krutikov, Vasiliy; Paranin, Sergey

    2015-07-01

    The magnetic pulse welding (MPW) technique was employed for the end closure joining of fuel pin cladding tubes made of ferritic-martensitic (FM) steel and oxide-dispersion strengthened (ODS) steel. The technique is a solid-state impact joining process based on the electromagnetic force, similar to explosive welding. For a given set of optimal process parameters, e.g., the end-plug geometry, the rigid metallurgical bonding between the tube and end plug was obtained by high-velocity impact collision accompanied with surface jetting. The joint region showed a typical wavy morphology with a narrow grain boundary-like bonding interface. There was no evidence of even local melting, and only the limited grain refinement was observed in the vicinity of the bonding interface without destructing the original reinforcement microstructure of the FM-ODS steel, i.e., a fine grain structure with oxide dispersion. No leaks were detected during helium leakage test, and moreover, the rupture occurred in the cladding tube section without leaving any joint damage during internal pressure burst test. All of the results proved the integrity and durability of the MPWed joints and signified the great potential of this method of end closure joining for advanced fast reactor fuel pin fabrication.

  7. Joining Forces

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The Chinese and U.S. navies are bound to work together for the common good of the international community Sino-U.S. military relations recently received another boost. The Japan-Ibased U.S. destroyer USS Fitzgerald joined Chinese and foreign naval vessels in a grand international fleet review to celebrate the 60th anniversary of the founding of the Navy of the People’s Liberation Army (PLA) in the coastal city of Qingdao

  8. Joining of polymer composite materials

    Energy Technology Data Exchange (ETDEWEB)

    Magness, F.H.

    1990-11-01

    Under ideal conditions load bearing structures would be designed without joints, thus eliminating a source of added weight, complexity and weakness. In reality the need for accessibility, repair, and inspectability, added to the size limitations imposed by the manufacturing process and transportation/assembly requirements mean that some minimum number of joints will be required in most structures. The designer generally has two methods for joining fiber composite materials, adhesive bonding and mechanical fastening. As the use of thermoplastic materials increases, a third joining technique -- welding -- will become more common. It is the purpose of this document to provide a review of the available sources pertinent to the design of joints in fiber composites. The primary emphasis is given to adhesive bonding and mechanical fastening with information coming from documentary sources as old as 1961 and as recent as 1989. A third, shorter section on composite welding is included in order to provide a relatively comprehensive treatment of the subject.

  9. Joining by plastic deformation

    DEFF Research Database (Denmark)

    Mori, Ken-ichiro; Bay, Niels; Fratini, Livan;

    2013-01-01

    opportunities to design new products through joining dissimilar materials. This paper aims to provide an overview of the state of the art in such joining processes, including cold welding, friction stir welding, self-pierce riveting, mechanical clinching and joining by forming. The paper includes description...

  10. Comparative analysis of the practice of China and Russia joining the WTO

    OpenAIRE

    Anastasia Sergeyevna Loginova; Liliya Andreevna Travina

    2015-01-01

    Objective to examine the positive and negative experience of China39s joining the World Trade Organization WTO that joined it on terms similar to the Russian ones for the best understanding of the advantages and disadvantages of joining and building the appropriate policy. Methods the objective of the work has been achieved through the application of both general and specific scientific methods. In particular the analysis and synthesis allowed to study the social and economic context...

  11. Assessment of alternative joining techniques for Ti–6Al–4V/CFRP hybrid joints regarding tensile and fatigue strength

    International Nuclear Information System (INIS)

    Highlights: • Nd:YAG laser riveting of Ti–6Al–4V/CFRP lap joint was successfully realized. • Tensile strength is comparable to that of conventional riveted lap joints. • Fatigue strength of conventional riveted joint can be increased by adhesive bonding. • The effect of adhesive bonding is comparable to surface structuring of Ti–6Al–4V. - Abstract: CFRP and titanium joints are used in the aerospace industry. These materials are usually joined by titanium rivets which are inserted into holes drilled through both materials. Conventional riveted hybrid joints of CFRP and titanium parts fail under quasi static loading due to the uneven load distribution at the titanium rivets. Under cyclic loading, the fatigue failure occurs mainly in the titanium part because of the higher notch sensitivity. The aim of this work is the comparison of different joining concepts in terms of stiffness, strength and fatigue limit. First, laser riveting, here titanium pins are Nd:YAG laser beam welded to the Ti–6Al–4V parts. Second, conventional riveted hybrid joint is combined with adhesive bonding. Third, surface structuring of the Ti–6Al–4V parts is used to enhance friction in the riveted joint. Tensile and fatigue tests as well as fractographical examinations are performed to establish the process–property–performance relationship of the hybrid joints. Laser riveting leads to higher stiffness but equal strength, when compared to conventional riveted joints. Fatigue life is improved by the implementation of adhesive bonding and surface structuring

  12. Bonding thermoplastic polymers

    Science.gov (United States)

    Wallow, Thomas I.; Hunter, Marion C.; Krafcik, Karen Lee; Morales, Alfredo M.; Simmons, Blake A.; Domeier, Linda A.

    2008-06-24

    We demonstrate a new method for joining patterned thermoplastic parts into layered structures. The method takes advantage of case-II permeant diffusion to generate dimensionally controlled, activated bonding layers at the surfaces being joined. It is capable of producing bonds characterized by cohesive failure while preserving the fidelity of patterned features in the bonding surfaces. This approach is uniquely suited to production of microfluidic multilayer structures, as it allows the bond-forming interface between plastic parts to be precisely manipulated at micrometer length scales. The bond enhancing procedure is easily integrated in standard process flows and requires no specialized equipment.

  13. Joining consensus of networked multi-agent systems with nonlinear couplings and weighting constraints

    Science.gov (United States)

    Wang, Bohui; Wang, Jingcheng; Zhang, Langwen; Ge, Yang

    2016-04-01

    This paper studies the joining consensus of networked multi-agent systems subject to nonlinear couplings and weighted directed graphs via pinning control. A weighted-average consensus protocol is proposed to achieve the collective decision by interacting with the local information of some pinned agents. By proposing a novel joining consensus protocol, average consensus and general consensus strategies are joined to achieve an agreement for the weighting networked system. Furthermore, by calculating a proper consensus gain and using finite control Lyapunov controllers, an efficient joining consensus protocol is presented to improve the consensus speed. Sufficient conditions for achieving the consensuses asymptotically are proved. Finally, theoretical results are validated via simulations.

  14. Predictive modeling of reactive wetting and metal joining.

    Energy Technology Data Exchange (ETDEWEB)

    van Swol, Frank B.

    2013-09-01

    The performance, reproducibility and reliability of metal joints are complex functions of the detailed history of physical processes involved in their creation. Prediction and control of these processes constitutes an intrinsically challenging multi-physics problem involving heating and melting a metal alloy and reactive wetting. Understanding this process requires coupling strong molecularscale chemistry at the interface with microscopic (diffusion) and macroscopic mass transport (flow) inside the liquid followed by subsequent cooling and solidification of the new metal mixture. The final joint displays compositional heterogeneity and its resulting microstructure largely determines the success or failure of the entire component. At present there exists no computational tool at Sandia that can predict the formation and success of a braze joint, as current capabilities lack the ability to capture surface/interface reactions and their effect on interface properties. This situation precludes us from implementing a proactive strategy to deal with joining problems. Here, we describe what is needed to arrive at a predictive modeling and simulation capability for multicomponent metals with complicated phase diagrams for melting and solidification, incorporating dissolutive and composition-dependent wetting.

  15. A review of the US joining technologies for plasma facing components in the ITER fusion reactor

    International Nuclear Information System (INIS)

    This paper is a review of the current joining technologies for plasma facing components in the US for the International Thermonuclear Experimental Reactor (ITER) project. Many facilities are involved in this project. Many unique and innovative joining techniques are being considered in the quest to join two candidate armor plate materials (beryllium and tungsten) to a copper base alloy heat sink (CuNiBe, OD copper, CuCrZr). These techniques include brazing and diffusion bonding, compliant layers at the bond interface, and the use of diffusion barrier coatings and diffusion enhancing coatings at the bond interfaces. The development and status of these joining techniques will be detailed in this report

  16. Meet and Join Matrices in the Poset of Exponential Divisors

    Indian Academy of Sciences (India)

    Ismo Korkee; Pentti Haukkanen

    2009-06-01

    It is well-known that $(\\mathbb{Z}_+,|)=(\\mathbb{Z}_+,GCD,LCM)$ is a lattice, where $|$ is the usual divisibility relation and $GCD$ and $LCM$ stand for the greatest common divisor and the least common multiple of positive integers. The number $d=\\prod^r_{k=1}p^{d^{(k)}}_k$ is said to be an exponential divisor or an -divisor of $n=\\prod^r_{k=1}p^{n^{(k)}}_k(n >1)$, written as $d|_e n$, if $d^{(k)}|n^{(k)}$ for all prime divisors $p_k$ of . It is easy to see that $(\\mathbb{Z}_+\\backslash\\{1\\},|_e)$ is a poset under the exponential divisibility relation but not a lattice, since the greatest common exponential divisor $(GCED)$ and the least common exponential multiple $(LCEM)$ do not always exist. In this paper we embed this poset in a lattice. As an application we study the $GCED$ and $LCEM$ matrices, analogues of $GCD$ and $LCM$ matrices, which are both special cases of meet and join matrices on lattices.

  17. Non-homologous end joining: advances and frontiers.

    Science.gov (United States)

    Yang, Kai; Guo, Rong; Xu, Dongyi

    2016-07-01

    DNA double-strand breaks (DSBs) are the most serious form of DNA damage. In human cells, non-homologous end joining (NHEJ) is the major pathway for the repair of DSBs. Different types of DSBs result in different subsets of NHEJ repair strategies. These variations in NHEJ repair strategies depend on numerous elements, such as the flexible recruitment of NHEJ-related proteins, the complexity of the DSB ends, and the spatial- and temporal-ordered formation of the multi-protein complex. On the one hand, current studies of DNA DSBs repair focus on the repair pathway choices between homologous recombination and classic or alternative NHEJ. On the other hand, increasing researches have also deepened the significance and dug into the cross-links between the NHEJ pathway and the area of genome organization and aging. Although remarkable progress has been made in elucidating the underlying principles during the past decades, the detailed mechanism of action in response to different types of DSBs remains largely unknown and needs further evaluation in the future study. PMID:27217473

  18. Realizing joined-up government: Dynamic capabilities and stage models for transformation

    NARCIS (Netherlands)

    Klievink, B.; Janssen, M.

    2009-01-01

    Joining up remains a high priority on the e-government agenda and requires extensive transformation. Stage models are predictable patterns which exist in the growth of organizations and unfold as discrete time periods that result in discontinuity and can help e-government development towards joined-

  19. Combustion Synthesis of NiAl and In-situ Joining to Ni-based Superalloy

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Combustion synthesis is used as a joining technology to join Ni-based superalloys with in-situ synthesized NiAl filler. The synthesis mechanism is discussed. The microstructure of the joints is investigated and the joint strength is also evaluated by tensile testing.

  20. Creep and tensile properties of press molding joined GMT-sheets

    Institute of Scientific and Technical Information of China (English)

    Jin-Woo KIM; Dong-Gi LEE

    2011-01-01

    GMT-sheet is used in automobile bumper with high rigidity and strength, and its joining strength is influenced by lap length, one of the joined molding conditions. Fracture strength was calculated by dividing fracture load with cross-sectional area.Total five repeated measurements were made to obtain the average value. Tensile test was conducted at room temperature for l0 specimens. In addition, the effect of compression ratio on creep and tensile performance during lap joined molding was discussed.With increasing lap length, the lap joining efficiency of GMT-sheet was increased. However, higher compression ratio reduced the joining efficiency. Creep test on GMT-sheet showed abrupt fracture without tertiary creep. This can be explained by the weak thermal resistance of the resin. If GMT-sheet was exposed to high temperature for a long time, it was easily failed by external force.

  1. Development of an Explosive Bonding Process for Producing High Strength Bonds between Niobium and 6061-T651 Aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Palmer, T A; Elmer, J W; Brasher, D; Butler, D; Riddle, R

    2005-09-23

    An explosive bonding procedure for joining 9.5 mm thick niobium plate to 203 mm thick 6061-T651 Al plate has been developed in order to maximize the bond tensile and impact strengths and the amount of bonded material across the surface of the plate. This procedure improves upon previous efforts, in which the 9.5 mm thick niobium plate is bonded directly to 6061-T4 Al plate. In this improved procedure, thin Nb and Al interlayers are explosively clad between the thicker niobium and aluminum plates. Bonds produced using these optimized parameters display a tensile strength of approximately 255 MPa and an impact strength per unit area of approximately 0.148 J/mm{sup 2}. Specialized mechanical testing geometries and procedures are required to measure these bond properties because of the unique bond geometry. In order to ensure that differences in the thermal expansion coefficients of aluminum and niobium do not adversely affect the bond strength, the effects of thermal cycling at temperatures between -22 C and 45 C on the mechanical properties of these bonds have also been investigated by testing samples in both the as-received and thermal cycled conditions. Based on the results obtained from this series of mechanical tests, thermal cycling is shown to have no adverse effect on the resulting tensile and impact strengths of the bonds produced using the optimized bonding parameters.

  2. Precision Joining Center

    Energy Technology Data Exchange (ETDEWEB)

    Powell, J.W.; Westphal, D.A.

    1991-08-01

    A workshop to obtain input from industry on the establishment of the Precision Joining Center (PJC) was held on July 10--12, 1991. The PJC is a center for training Joining Technologists in advanced joining techniques and concepts in order to promote the competitiveness of US industry. The center will be established as part of the DOE Defense Programs Technology Commercialization Initiative, and operated by EG G Rocky Flats in cooperation with the American Welding Society and the Colorado School of Mines Center for Welding and Joining Research. The overall objectives of the workshop were to validate the need for a Joining Technologists to fill the gap between the welding operator and the welding engineer, and to assure that the PJC will train individuals to satisfy that need. The consensus of the workshop participants was that the Joining Technologist is a necessary position in industry, and is currently used, with some variation, by many companies. It was agreed that the PJC core curriculum, as presented, would produce a Joining Technologist of value to industries that use precision joining techniques. The advantage of the PJC would be to train the Joining Technologist much more quickly and more completely. The proposed emphasis of the PJC curriculum on equipment intensive and hands-on training was judged to be essential.

  3. Mounting and joining technology for the dosimetric and control pipelines of WWER-440 type power reactors

    International Nuclear Information System (INIS)

    The development of the mounting and joining technology for the pulse tubes and dosimetric pipelines is described. A GRW type welding machine was chosen for the mechanized welding of austenitic steel pulse tubes. The technology is very effective, high quality of joints can be attained even by workers of low qualification. For the joining of aluminium tubes of the dosimetric pipeline a sticking technology using epoxy adhesive resins has been developed. The AN 134 type resin proved to be very effective. (author)

  4. Wafer bonding applications and technology

    CERN Document Server

    Gösele, Ulrich

    2004-01-01

    During the past decade direct wafer bonding has developed into a mature materials integration technology. This book presents state-of-the-art reviews of the most important applications of wafer bonding written by experts from industry and academia. The topics include bonding-based fabrication methods of silicon-on-insulator, photonic crystals, VCSELs, SiGe-based FETs, MEMS together with hybrid integration and laser lift-off. The non-specialist will learn about the basics of wafer bonding and its various application areas, while the researcher in the field will find up-to-date information about this fast-moving area, including relevant patent information.

  5. Mezzanine finance and corporate bonds

    OpenAIRE

    Libena TETREVOVA

    2009-01-01

    The article deals with the problems of mezzanine finance in relation to corporate bonds. Firstly, attention is paid to definition of mezzanine finance. The term mezzanine finance is used as a term for hybrid forms of financing that combine elements of debt and equity financing. Mezzanine finance represents an alternative form of financing corporate activities. Secondly, possible forms of mezzanine finance are characterized. We can say that special types of corporate bonds (convertible bonds a...

  6. When and Whom to Join: The Expansion of Ongoing Violent Interstate Conflicts

    OpenAIRE

    Bayer, Reşat; Joyce, Kyle A.; Ghosn, Faten

    2014-01-01

    The opportunity and willingness framework has received much attention in research on interstate conflict expansion. This framework is extended here by examining when and what side third parties join during ongoing conflicts. It is maintained that without examining both timing and side selection, understanding of conflict expansion is limited. The timing and side joined in interstate disputes between 1816 and 2001 are analysed using a competing risks duration model. The findings contribute nov...

  7. Joining of 14YWT and F82H by Friction Stir Welding

    Energy Technology Data Exchange (ETDEWEB)

    Hoelzer, David T [ORNL; Unocic, Kinga A [ORNL; Sokolov, Mikhail A [ORNL; Feng, Zhili [ORNL

    2013-01-01

    The feasibility of using friction stir welding (FSW) to join specimens of the advanced oxide dispersion strengthened (ODS) 14YWT nanostructured ferritic alloy (NFA) and a plate of F82H tempered martensitic steel (TMS) was investigated. The sample used in the FSW experiment consisted of spot welding four specimens 14YWT prepared from prior tested dual notch fracture toughness bend bars in a corresponding slot that was machined in the F82H plate. The FSW run was successfully performed on the sample using a polycrystalline boron nitride tool (PCBN) that resulted in joints showing good bonding between butt joints of 14YWT specimens and 14YWT specimens and F82H plate. The joints were characterized by light microscopy and SEM analysis and were observed to be relatively narrow in width. The ultra-fine grain size associated with 14YWT increased by a factor of up to 3 while that of F82H was refined by a considerable amount in the thermomechanically affected zones (TMAZ) due to FSW. In addition, porosity was observed in the TMAZ of 14YWT on the advancing side of the FSW joint and at the interface between F82H and 14YWT. Vickers hardness (VH) measurements showed a decrease of ~120 VH from ~500 VH (~20% decrease) for 14YWT and an increase of ~220 VH from ~220 VH (~100% increase) for F82H in the FSW zones. Further refinements in the FSW process will be required to minimize defects including porosity.

  8. Joining of 14YWT and F82H by friction stir welding

    Energy Technology Data Exchange (ETDEWEB)

    Hoelzer, D.T., E-mail: hoelzerd@ornl.gov; Unocic, K.A.; Sokolov, M.A.; Feng, Z.

    2013-11-15

    Friction stir welding was investigated for joining specimens of the ODS 14YWT ferritic alloy together and to an F82H tempered martensitic steel plate. The FSW run was performed using a polycrystalline boron nitride tool and resulted in good bonding between 14YWT/14YWT and 14YWT/F82H. Joints and interfaces were observed by light microscopy and SEM analysis to be narrow in width. The ultra-small grain size of 14YWT increased by a factor up to 4 while that of F82H decreased by a considerable amount in the weld zones. The TEM analysis showed no significant changes in the size of the oxygen-enriched nanoclusters in the weld zone of 14YWT. However, defects such as a wormhole on the advancing side of the weld zone in 14YWT and small pores associated with joints and interfaces were observed in the FSW sample. The hardness measurements from unaffected zone into weld zones showed ∼20% decrease in hardness for 14YWT (from ∼500 VH to ∼380 VH) and ∼100% increase in hardness of F82H (from ∼220 VH to ∼440 VH)

  9. Credit default swaps, bond spreads and the bond market

    OpenAIRE

    Zhu, Meicheng

    2014-01-01

    With the rapid development of the credit default swap (CDS) market, the issue of how the introduction of CDSs affects the corporate bond market has been of particular interest to researchers and policy makers. This has been investigated in the literature from two perspectives. One is to examine the relationship between the CDS and the bond markets in price discovery, and the other is concerned with researching the CDS trading effects on bond spreads. Referring to the former approach, most rel...

  10. Solder extrusion pressure bonding process and bonded products produced thereby

    Science.gov (United States)

    Beavis, Leonard C.; Karnowsky, Maurice M.; Yost, Frederick G.

    1992-01-01

    Production of soldered joints which are highly reliable and capable of surviving 10,000 thermal cycles between about -40.degree. C. and 110.degree. C. Process involves interposing a thin layer of a metal solder composition between the metal surfaces of members to be bonded and applying heat and up to about 1000 psi compression pressure to the superposed members, in the presence of a reducing atmosphere, to extrude the major amount of the solder composition, contaminants including fluxing gases and air, from between the members being bonded, to form a very thin, strong intermetallic bonding layer having a thermal expansion tolerant with that of the bonded members.

  11. Recombination, transcription, and diversity of a partially germline-joined VH in a mammal.

    Science.gov (United States)

    Wang, Xinxin; Miller, Robert D

    2012-09-01

    Full or partially germline-joined V genes have been described in a number of different vertebrate lineages where they can contribute to the expressed antibody repertoire through different mechanisms. Here we demonstrate that VH3.1, a partially germline-joined VH gene in the opossum Monodelphis domestica, can undergo V(D)J recombination to generate productive IgH transcripts. VH3.1 is fused to a DH gene segment in the germline DNA and is the only known example of a germline-joined VH in a mammal. B cells that have recombined VH3.1 were not detected until nearly 2 months of age, around the time of weaning, and much later than B cells using the conventional VH. Compared to opossum IgH transcripts using the conventional VH genes, those with VH3.1 have unusually long CDR3 due to the length of the germline-joined DH.

  12. Spatial join optimization among WFSs based on recursive partitioning and filtering rate estimation

    Science.gov (United States)

    Lan, Guiwen; Wu, Congcong; Shi, Guangyi; Chen, Qi; Yang, Zhao

    2015-12-01

    Spatial join among Web Feature Services (WFS) is time-consuming for most of non-candidate spatial objects may be encoded by GML and transferred to client side. In this paper, an optimization strategy is proposed to enhance performance of these joins by filtering non-candidate spatial objects as many as possible. By recursive partitioning, the data skew of sub-areas is facilitated to reduce data transmission using spatial semi-join. Moreover filtering rate is used to determine whether a spatial semi-join for a sub-area is profitable and choose a suitable execution plan for it. The experimental results show that the proposed strategy is feasible under most circumstances.

  13. Modeling and experimental evaluation of the diffusion bonding of the oxide dispersion strengthened steel PM2000

    Science.gov (United States)

    Sittel, Wiebke; Basuki, Widodo W.; Aktaa, Jarir

    2015-10-01

    A modeling based optimization process of the solid state diffusion bonding is presented for joining ferritic oxide dispersion strengthened steels PM2000. An optimization study employing varying bonding temperatures and pressures results in almost the same strength and toughness of the bonded compared to the as received material. TEM investigations of diffusion bonded samples show a homogeneous distribution of oxide particles at the bonding seam similar to that in the bulk. Hence, no loss in strength or creep resistance due to oxide particle agglomeration is found, as verified by the mechanical properties observed for the joint.

  14. Human transcriptional coactivator PC4 stimulates DNA end joining and activates DSB repair activity.

    Science.gov (United States)

    Batta, Kiran; Yokokawa, Masatoshi; Takeyasu, Kunio; Kundu, Tapas K

    2009-01-23

    Human transcriptional coactivator PC4 is a highly abundant nuclear protein that is involved in diverse cellular processes ranging from transcription to chromatin organization. Earlier, we have shown that PC4, a positive activator of p53, overexpresses upon genotoxic insult in a p53-dependent manner. In the present study, we show that PC4 stimulates ligase-mediated DNA end joining irrespective of the source of DNA ligase. Pull-down assays reveal that PC4 helps in the association of DNA ends through its C-terminal domain. In vitro nonhomologous end-joining assays with cell-free extracts show that PC4 enhances the joining of noncomplementary DNA ends. Interestingly, we found that PC4 activates double-strand break (DSB) repair activity through stimulation of DSB rejoining in vivo. Together, these findings demonstrate PC4 as an activator of nonhomologous end joining and DSB repair activity.

  15. Study of international published experiences in joining copper and copper-alloys

    International Nuclear Information System (INIS)

    This study has revealed a number of joining processes to be used when manufacturing copper-canisters for the final storage of high level nuclear waste. However, the decision on which material and which joining process to be used has to be based on the design criterions. The welding procedure has to be qualified, i.e. it shall be demonstrated whether the procedure is capable of fulfilling specified requirements. 32 refs

  16. A Review of Similar and Dissimilar Micro-joining of Nitinol

    Science.gov (United States)

    Deepan Bharathi Kannan, T.; Ramesh, T.; Sathiya, P.

    2016-04-01

    NiTinol belongs to a class of smart materials which has a wide range of applications in the field of automotive, aerospace, biomedical, robotics, etc., owing to the growing trend in miniaturization of components. Micro-joining is becoming one of the important and familiar processes in the fabrication of miniaturized components. Recently, effective micro-joining of thin sheets has been gaining a lot of interest among researchers. In this article, the research and progress in micro-joining of NiTinol to itself and other metals are reviewed at different aspects. To date, laser welding, tungsten inert gas welding, and resistance welding have been used to a large extent in investigating the weldability of NiTinol alloys. Some important welding parameters used in micro joining by various researchers and their effects on weld qualities are detailed in this review. Metallurgical aspects, mechanical properties and corrosion aspects of micro-joined NiTinol sheets/wires are discussed. The aim of this report is to review the recent progress in micro-joining of NiTinol and to provide a basis for follow-on research.

  17. Laser hybrid joining of plastic and metal components for lightweight components

    Science.gov (United States)

    Rauschenberger, J.; Cenigaonaindia, A.; Keseberg, J.; Vogler, D.; Gubler, U.; Liébana, F.

    2015-03-01

    Plastic-metal hybrids are replacing all-metal structures in the automotive, aerospace and other industries at an accelerated rate. The trend towards lightweight construction increasingly demands the usage of polymer components in drive trains, car bodies, gaskets and other applications. However, laser joining of polymers to metals presents significantly greater challenges compared with standard welding processes. We present recent advances in laser hybrid joining processes. Firstly, several metal pre-structuring methods, including selective laser melting (SLM) are characterized and their ability to provide undercut structures in the metal assessed. Secondly, process parameter ranges for hybrid joining of a number of metals (steel, stainless steel, etc.) and polymers (MABS, PA6.6-GF35, PC, PP) are given. Both transmission and direct laser joining processes are presented. Optical heads and clamping devices specifically tailored to the hybrid joining process are introduced. Extensive lap-shear test results are shown that demonstrate that joint strengths exceeding the base material strength (cohesive failure) can be reached with metal-polymer joining. Weathering test series prove that such joints are able to withstand environmental influences typical in targeted fields of application. The obtained results pave the way toward implementing metalpolymer joints in manufacturing processes.

  18. Adhesive Bonding of Aluminium Alloy A5754 by Epoxy Resins

    Directory of Open Access Journals (Sweden)

    Ivan Michalec

    2013-01-01

    Full Text Available Joining thin sheets of aluminium and its alloys is a promising area in the field of joining materials. Nowadays, joining methods that do not melt the material itself are increasingly being utilised. This paper deals with adhesive bonding of aluminium alloy A5754 by two-component epoxy resins. Theresults show that joints bonded by Hysol 9466 have appropriate mechanical properties, but that joints bonded by Hysol 9492 have better thermal stability.

  19. Comparative analysis of the practice of China and Russia joining the WTO

    Directory of Open Access Journals (Sweden)

    Anastasia Sergeyevna Loginova

    2015-09-01

    Full Text Available Objective to examine the positive and negative experience of China39s joining the World Trade Organization WTO that joined it on terms similar to the Russian ones for the best understanding of the advantages and disadvantages of joining and building the appropriate policy. Methods the objective of the work has been achieved through the application of both general and specific scientific methods. In particular the analysis and synthesis allowed to study the social and economic context of the state in the framework of joining the WTO the consequences of such membership and to identify the key areas for improvement of this step for Russia. Statistical techniques were used in the process of gathering information about the key economic indicators. The fundamental method was comparativelegal which made it possible to draw parallels in joining the WTO by various states. Results basing on the measures taken by China both before and after joining the WTO as well as evaluation of their implication the conclusion was made about its successful experience. The actions before joining were very effective. In particular they are applicable to the fields of agriculture automotive industry investment policy etc. The measures of nonaddress subsidizing maintaining the socioeconomic stability in the country the export orientation of the economy along with functioning of special economic zones with joint ventures are in the authors39 opinion constructive actions for Russiarsquos adaptation to the WTO. Scientific novelty for the first time the thesis is put forward about the similarity of the Russia and China conditions when joining the WTO. The analysis is made of the complex measures preceding and following the joining. The necessity is grounded of reflecting the China39s positive and negative experiences in the Russian policy. Practical significance the main provisions and conclusions can be used in the research activity in addressing the issues of Russiarsquos

  20. Solid-Liquid Interdiffusion Bonding of Silicon Carbide to Steel for High Temperature MEMS Sensor Packaging and Bonding

    Science.gov (United States)

    Chan, Matthew Wei-Jen

    Complex engineering systems ranging from automobile engines to geothermal wells require specialized sensors to monitor conditions such as pressure, acceleration and temperature in order to improve efficiency and monitor component lifetime in what may be high temperature, corrosive, harsh environments. Microelectromechanical systems (MEMS) have demonstrated their ability to precisely and accurately take measurements under such conditions. The systems being monitored are typically made from metals, such as steel, while the MEMS sensors used for monitoring are commonly fabricated from silicon, silicon carbide and aluminum nitride, and so there is a sizable thermal expansion mismatch between the two. For these engineering applications the direct bonding of MEMS sensors to the components being monitored is often required. This introduces several challenges, namely the development of a bond that is capable of surviving high temperature harsh environments while mitigating the thermally induced strains produced during bonding. This project investigates the development of a robust packaging and bonding process, using the gold-tin metal system and the solid-liquid interdiffusion (SLID) bonding process, to join silicon carbide substrates directly to type-316 stainless steel. The SLID process enables bonding at lower temperatures while producing a bond capable of surviving higher temperatures. Finite element analysis was performed to model the thermally induced strains generated in the bond and to understand the optimal way to design the bond. The cross-sectional composition of the bonds has been analyzed and the bond strength has been investigated using die shear testing. The effects of high temperature aging on the bond's strength and the metallurgy of the bond were studied. Additionally, loading of the bond was performed at temperatures over 415 °C, more than 100 °C, above the temperature used for bonding, with full survival of the bond, thus demonstrating the benefit of

  1. Innovative cold joining technologies based on tube forming

    Directory of Open Access Journals (Sweden)

    Alves Luis M.

    2015-01-01

    Full Text Available This paper is focused on innovative cold joining technologies for connecting tubes and fixing tubes to sheets. The proposed technologies are based on the utilization of plastic instability waves in thin-walled tubes subjected to axial compression and may be seen as an alternative to conventional joining technologies based on mechanical fixing with fasteners, welding and structural adhesive bonding. Besides allowing connecting dissimilar materials and being successfully employed in fixture conditions that are difficult and costly to achieve by means of conventional joining the new proposed technologies also cope with the growing concerns on the demand, lifecycle and recycling of materials.

  2. Pulse joining cartridges

    Energy Technology Data Exchange (ETDEWEB)

    Golovashchenko, Sergey Fedorovich; Bonnen, John Joseph Francis

    2016-08-23

    A pulsed joining tool includes a tool body that defines a cavity that receives an inner tubular member and an outer tubular member and a pulse joining cartridge. The tubular members are nested together with the cartridge being disposed around the outer tubular member. The cartridge includes a conductor, such as a wire or foil, that extends around the outer tubular member and is insulated to separate a supply segment from a return segment. A source of stored electrical energy is discharged through the conductor to join the tubular members with an electromagnetic force pulse.

  3. Weld bonding of stainless steel

    DEFF Research Database (Denmark)

    Santos, I. O.; Zhang, Wenqi; Goncalves, V.M.;

    2004-01-01

    This paper presents a comprehensive theoretical and experimental investigation of the weld bonding process with the purpose of evaluating its relative performance in case of joining stainless steel parts, against alternative solutions based on structural adhesives or conventional spot-welding. Th......This paper presents a comprehensive theoretical and experimental investigation of the weld bonding process with the purpose of evaluating its relative performance in case of joining stainless steel parts, against alternative solutions based on structural adhesives or conventional spot...

  4. Innovative and Highly Productive Joining Technologies for Multi-Material Lightweight Car Body Structures

    Science.gov (United States)

    Meschut, G.; Janzen, V.; Olfermann, T.

    2014-05-01

    Driven by increasing costs for energy and raw material and especially by the European CO2-emission laws, automotive industry faces the challenge to develop more lightweight and at the same time still rigid and crash-stable car bodies, that are affordable for large-scale production. The implementation of weight-reduced constructions depends not only on the availability of lightweight materials and related forming technologies, but also on cost-efficient and reliable joining technologies suitable for multi-material design. This article discusses the challenges and requirements for these technologies, based on the example of joining aluminium with press-hardened boron steels, what is considered as a very important material combination for affordable future lightweight mobility. Besides a presentation of recent developments for extending the process limits of conventional mechanical joining methods, new promising technologies such as resistance element welding are introduced. In addition, the performance, advantages, and disadvantages of the presented technologies are compared and discussed.

  5. Glass-ceramic joining and coating of SiC/SiC for fusion applications

    International Nuclear Information System (INIS)

    The aim of this work is the joining and the coating of SiC/SiC composites by a simple, pressureless, low cost technique. A calcia-alumina glass-ceramic was chosen as joining and coating material, because its thermal and thermomechanical properties can be tailored by changing the composition, it does not contain boron oxide (incompatible with fusion applications) and it has high characteristic temperatures (softening point at about 1400 C). Furthermore, the absence of silica makes this glass-ceramic compatible with ceramic breeder materials (i.e. lithium-silicates, -alluminates or -zirconates). Coatings and joints were successfully obtained with Hi-Nicalon fiber-reinforced CVI silicon carbide matrix composite. Mechanical shear strength tests were performed on joined samples and the compatibility with a ceramic breeder material was examined. (orig.)

  6. Developments in laser joining and welding of plastics using high-power laser diodes

    Science.gov (United States)

    Hoult, Tony; Ong, Raymond

    2002-02-01

    Diode lasers are now being employed in industry for a range of applications, in particular they are starting to be used as alternatives to conventional techniques for thermal joining of plastics. This is being assisted by the use of improved reliability aluminum-free diodes and diode laser systems, partly due to a better understanding of failure mechanisms. The laser welding and related techniques are dependent on transmission of part of an infra-red beam through the upper layer of a joint and semi-quantitative assessment of this is required for specific applications. The technique is applicable not only to high average powers, but also to very low average power, in this regime delicate thin-walled components may be joined. Recent developments using derivatives of this technique have shown that a wide range of similar and dissimilar material combinations may be joined.

  7. The CMT-process and its possible applications, especially joining of steel with aluminium; Der CMT - Prozess und seine Moeglichkeiten, im speziellen das Fuegen von Stahl mit Aluminium

    Energy Technology Data Exchange (ETDEWEB)

    Bruckner, J.; Himmelbauer, K.; Hackl, H. [Fronius International GmbH, Wels (Austria)

    2004-07-01

    Knowing how to weld dissimilar metals is becoming more and more important. One reason is that it's often impossible for one material to provide the optimum chemical, physical, and mechanical characteristics needed for an application. For this reason, as well as cost efficiency, technology specialists are experimenting with different joining processes to weld bimetal joints optimally. A reliable method of joining the two most commonly used metals, steel and aluminum, would make it possible to make these joints in several applications. On one hand, aluminum is becoming increasingly more important in the automotive industry because of its good processing and performance characteristics and because it's lightweight, which results in lower fuel consumption. Given today's heightened need to decrease energy consumption, aluminum is a major player in modern-day mechanical engineering. On the other hand, steel continues to dominate many fields of engineering, a fact underlined by the development of high-strength and superhigh-strength steels. When different metals are joined, each metal's features should be considered. It's important to pay attention to the chemical and physical properties-such as the corrosion behavior and thermal expansion coefficient-and to atomic properties, such as the lattice constant and type of crystalline lattice. Processes typically used to join dissimilar metals are bonding, riveting, or clinching, which essentially have no influence on the metals' atomic properties. Another method, thermal joining, can shorten joining time, produce tight seams, and provide high strength. (orig.)

  8.  Optimizing relational algebra operations using discrimination-based joins and lazy products

    DEFF Research Database (Denmark)

    Henglein, Fritz

    to a specied equivalence relation on keys the values are associated with. We show how discriminators can be dened generically, purely functionally, and eciently (worst-case linear time) on top of the array-based basic multiset discrimination algorithm of Cai and Paige (1995). Discriminators provide the basis...... for discrimination-based joins, a new technique for computing joins that requires neither hashing nor sorting. Discriminators also provide ecient implementations for eliminating duplicates, set union and set dierence. We represent a cross-product lazily as a formal pair of the argument sets (relations). This allows...

  9. [Joining WHO of Republic of Korea and the projects in the 1950s].

    Science.gov (United States)

    Lee, Sun Ho

    2014-04-01

    The Republic of Korea(ROK) and the World Health Organization(WHO) have done many projects successfully from 1949, in which the government of First Republic joined the WHO. However the relation between the ROK and the WHO have not been studied very much so far. The main purpose of this research, which could be done by the support of WHO, is connected with three questions. First research point would be "how could the ROK joined WHO in 1949 and what's the meaning of it? And the what's the difference in the process for the WHO between the ROK of 1949 and the DPRK(Democratic People's Republic of Korea) of 1973?" The first president of the ROK, Rhee Syngman, who had received his Ph. D.(about international politics) from Princeton University in 1910, was strongly interested in joining international institutes like UN, WHO. The ROK that could join WHO on 17 August 1949, with the approval of Assembly on 25 May 1949, was one of the founder members of the Western Pacific Region. By joining WHO, the ROK could get chance to increase the level of public health and its administration in 1950's. But the DPRK manage to became a member of WHO on 19 May 1973 and joined the South-East Asia Region. The joining of DPRK was influenced by the easing of the cold war after the Nixon Doctrine and the joining of the China(People's Republic of China). Second research point would be "What kind of roll did the WHO take in the First Republic?" Yet the public health administration of the First Republic that had been made in the period of US army military government was been strongly influenced by USA, the roll of WHO was also important in the 1950's. Last research point would be "What kind of the projects did the ROK and the WHO take part in during the period of he First Republic? How could evaluate the results?" The ROK and the WHO handled the projects including health services, communicable disease prevention and control, control of noncommunicable diseases, and protection of health. Specially

  10. Molecular dynamics simulation of joining process of Ag-Au nanowires and mechanical properties of the hybrid nanojoint

    Directory of Open Access Journals (Sweden)

    Su Ding

    2015-05-01

    Full Text Available The nanojoining process of Ag-Au hybrid nanowires at 800K was comprehensively studied by virtue of molecular dynamics (MD simulation. Three kinds of configurations including end-to-end, T-like and X-like were built in the simulation aiming to understand the nanojoining mechanism. The detailed dynamic evolution of atoms, crystal structure transformation and defects development during the nanojoining processes were performed. The results indicate that there are two stages in the nanojoining process of Ag-Au nanowires which are atom diffusion and new bonds formation. Temperature is a key parameter affecting both stages ascribed to the energy supply and the optimum temperature for Ag-Au nanojoint with diameter of 4.08 nm has been discussed. The mechanical properties of the nanojoint were examined with simulation of tensile test on the end-to-end joint. It was revealed that the nanojoint was strong enough to resist fracture at the joining area.

  11. Hot rolling joining process

    International Nuclear Information System (INIS)

    In the case of incorporating nonferrous metal equipment in fuel reprocessing processes, from the viewpoint of reducing maintenance works for the piping connection to peripheral equipments, it is desirable to adopt the pipe joints of joining the materials of different kinds, which have the high reliability against leakage. In order to meet this demand, the development of the manufacturing technology of the pipe joints by hot rolling process has been carried out. As for the structure of this pipe joint, a small diameter nonferrous metal pipe and a large diameter stainless steel pipe are joined by hot rolling by using an inserted material. The materials are Ti-5% Ta, Ti and Zr for the nonferrous metals, SUS 304L for the stainless steel, and Ta foil for the inserted material. The merits and demerits of this pipe joints are shown. The control of the interface structure in the joining of different materials was carried out by using the inserted material. The method of manufacturing the pipe joints and the proper conditions of the rolling joining are explained. As for the performance of the pipe joints, the evaluations of the defects in the joining interface, the strength of the joining, the corrosion resistance and the susceptibility to stress corrosion cracking are reported. (K.I.)

  12. Loosening and damage mechanism of thread-joined structures in nuclear power equipment

    International Nuclear Information System (INIS)

    The author proposes a loosening mechanism of thread-joined structures under vibrate environments in the nuclear power equipment and structures, which is on the base of the macro and imperceptible-mechanics analysis. It has answered the problems on the seizing, the adhesive wearing, the generation of cracks, the thread-tooth fracture. So it has a conclusion that the loosening of thread-joined structures is essential trend, in other words, the locking property of thread-pair is failure under vibrate environments

  13. Kinematics analysis and optimization of the fast shearing-extrusion joining mechanism for solid-state metal

    Science.gov (United States)

    Zhang, Shuangjie; Yao, Yunfeng; Li, Lingchong; Wang, Lijuan; Li, Junxia; Li, Qiang

    2015-11-01

    Dynamical Joining of the solid-state metal is the key technology to realize endless hot rolling. The heating and laser welding method both require long joining time. Based on super deformation method, a 7-bar and 2-slider mechanism was developed in Japan, and the joining time is less than 0.5 s, however the length of each bar are not reported and this mechanism is complex. A relatively simple 6-bar and 1-slider mechanism is put forward, which can realize the shearing and extrusion motion of the top and bottom blades with a speed approximately equal to the speed of the metal plates. In order to study the kinematics property of the double blades, based on complex vector method, the multi-rigid-body model is built, and the displacement and speed functions of the double blades, the joining time and joining thickness are deduced, the kinematics analysis shows that the initial parameters can't satisfy the joining process. Hence, optimization of this mechanism is employed using genetic algorithm(GA) and the optimization parameters of this mechanism are obtained, the kinematics analysis show that the joining time is less than 0.1 s, the joining thickness is more than 80% of the thickness of the solid-state metal, and the horizontal speeds of the blades are improved. A new mechanism is provided for the joining of the solid-state metal and a foundation is laid for the design of the device.

  14. Esquel Group and LEGO Group Joined Hands to Establish "Mindstorms Robotics Workshop"

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ With a mission"To encourage the Spirit of Learning"and to enhance learning opportunities for children in need,Esquel Group joined hands with Lego Group,and Semia Limited and established"Mindstorms Robotics Workshop"and donated RMB 200,000worth of educational robotic equipments to the Xinjiang Science and Technology Museum.

  15. PRESS RELEASE-Foseco and ProService Join Forces for Thermal Analysis Systems

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ Foseco and ProService have joined forces to drive the development of thermal analysis as the leading metallurgical control tool for iron foundries. As part of the agreement, Foseco has funded the development of a web-based version of ITACA and ProService have appointed Foseco as exclusive distributors for its ITACA Thermal Analysis systems.

  16. Performance Comparison of the Optimized Inverted Joined Wing Airplane Concept and Classical Configuration Airplanes

    Directory of Open Access Journals (Sweden)

    Sieradzki Adam

    2016-09-01

    Full Text Available The joined wing concept is an unconventional airplane configuration, known since the mid-twenties of the last century. It has several possible advantages, like reduction of the induced drag and weight due to the closed wing concept. The inverted joined wing variant is its rarely considered version, with the front wing being situated above the aft wing. The following paper presents a performance prediction of the recently optimized configuration of this airplane. Flight characteristics obtained numerically were compared with the performance of two classical configuration airplanes of similar category. Their computational fluid dynamics (CFD models were created basing on available documentation, photographs and some inverse engineering methods. The analysis included simulations performed for a scale of 3-meter wingspan inverted joined wing demonstrator and also for real-scale manned airplanes. Therefore, the results of CFD calculations allowed us to assess the competitiveness of the presented concept, as compared to the most technologically advanced airplanes designed and manufactured to date. At the end of the paper, the areas where the inverted joined wing is better than conventional airplane were predicted and new research possibilities were described.

  17. CCI and CI Join Hands:A Better Supply Chain with More Innovations on Cotton Fabrics

    Institute of Scientific and Technical Information of China (English)

    Tom; Xue

    2010-01-01

    Cotton Council International("CCI")and Cotton Incorporated("CI") joined forces again,from October 19-22,2010 at Intertextile Shanghai,to promote natural fiber-U.S.cotton.As global textile strategic partners,both organizations were bringing together alliances through the cotton

  18. Ex-WTO Chief and lndustry Veteran join CNOOC's Advisory Body

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    CNOOC Limited announced on March 20 that world-renowned corporate leaders, Mr. Peter Sutherland, a non-executive Chairman of BP plc andex-Director general of WTO organization and Professor Cornelius Herkstrǒter, a retired Chairman of Royal Dutch/Shell have joined the International Advisory Board (“IAB”) of the Company.

  19. The Ku80 carboxy terminus stimulates joining and artemis-mediated processing of DNA ends

    DEFF Research Database (Denmark)

    Weterings, Eric; Verkaik, Nicole S; Keijzers, Guido;

    2008-01-01

    Repair of DNA double-strand breaks (DSBs) is predominantly mediated by nonhomologous end joining (NHEJ) in mammalian cells. NHEJ requires binding of the Ku70-Ku80 heterodimer (Ku70/80) to the DNA ends and subsequent recruitment of the DNA-dependent protein kinase catalytic subunit (DNA-PK(CS)) an...

  20. Halogen Bonding in Organic Synthesis and Organocatalysis.

    Science.gov (United States)

    Bulfield, David; Huber, Stefan M

    2016-10-01

    Halogen bonding is a noncovalent interaction similar to hydrogen bonding, which is based on electrophilic halogen substituents. Hydrogen-bonding-based organocatalysis is a well-established strategy which has found numerous applications in recent years. In light of this, halogen bonding has recently been introduced as a key interaction for the design of activators or organocatalysts that is complementary to hydrogen bonding. This Concept features a discussion on the history and electronic origin of halogen bonding, summarizes all relevant examples of its application in organocatalysis, and provides an overview on the use of cationic or polyfluorinated halogen-bond donors in halide abstraction reactions or in the activation of neutral organic substrates.

  1. Joining the club: Conforming to and resisting biology in practice

    Science.gov (United States)

    Buxton, Cory Alexander

    2000-10-01

    This study explores how science and scientists were produced and reproduced within the setting of a university biology department. It builds upon recent work in anthropology of education and feminist science studies. My purpose was to look at both the contextual and constitutive values of science as they were negotiated and played out in the training of scientists in a setting where: (1) women were well represented in leadership positions; and (2) "mainstream" science was being both taught and practiced. Findings included the organization of a status hierarchy within the department, the meanings of science and scientists that students constructed within the social spaces they occupied, examples of individual resistance to certain norms of biology practice, and examples of institutional opposition to that resistance. There was some evidence that the unusually high representation of women in positions of leadership in the biology department did result in changes in both the contextual and constitutive values of how science was conceptualized, practiced and taught in this setting. Contextually, social spaces controlled by women were likely to emphasize: (1) teamwork bringing together participants with varied backgrounds and perspectives; (2) flexible and collaborative use of physical space; and (3) willingness to do work for which they went unacknowledged or to share rewards equally even when the work distribution was not equitable. Constitutively, these social spaces were prone to: (1) interdisciplinary synthesis and comprehensive approaches; (2) the study of topics that reconsidered beliefs about gender roles in plant and animal reproduction; (3) work that would be slower and take longer to produce (and publish) but might make a large contribution (be a high quality product) eventually; and (4) an awareness by women that their practices were different in some ways than the practices of their male colleagues.

  2. Talking REDD+: Beyond forestry - joining up and moving forward

    Energy Technology Data Exchange (ETDEWEB)

    Nhantumbo, Isilda; Rolington, Leianne

    2011-12-15

    On Sunday 27 November 2011, the eve of the 17th conference of the parties to the UNFCCC (COP17), the International Institute for Environment and Development, together with its partners, hosted a South-South learning event, 'REDD+, poverty reduction and sustainable development: are there cost-effective and pro-poor options?' This was a platform to share information about the practices that already work, to discuss how REDD+ can build on and scale up cost-effective options that deal with the fundamental problem of climate change. Deforestation and degradation of forests requires concerted interventions across national and regional borders. Learning from each other's experience in dealing with the underlying problems and understanding how to adapt them to a different local context is critical – and will help to both ensure its success and to lower transaction costs. This briefing gives an overview of the key REDD+ issues, in particular: integrating mitigation and adaptation actions; addressing tenure; learning from participatory forest management and payment for ecosystems services; taking the right approach to gender; developing safeguards to minimize negative impacts of REDD+; and strengthening South-South collaboration to reduce the transaction costs of REDD+.

  3. Shanghai and Hong Kong Join Efforts for Oil Futures Exchanges

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    @@ Shanghai Futures Exchange (SHFE) and Hong Kong Exchanges and Clearing Limited (HKEx) announced in midApril they will jointly introduce crude oil futures. The two exchanges will jointly develop an energy derivatives market that serves both Chinese and international investors,according to a memorandum of understanding (MOU) signed between the two exchanges.

  4. Status of Joining Thin Sheet and Thin Wall Tubes of 14YWT

    Energy Technology Data Exchange (ETDEWEB)

    Hoelzer, David T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Unocic, Kinga A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Tang, Wei [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Feng, Zhili [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-09-18

    Beginning this fiscal year, the FCRD research project initiated an investigation on joining thin sections of the advanced ODS 14YWT ferritic alloy. Friction stir welding (FSW) was investigated as a method to join thin plate and tubing of 14YWT since it is a solid state joining method that has been shown in past studies to be a promising method for joining plates of ODS alloys, such as 14YWT. However, this study will attempt to be the first to demonstrate if FSW can successfully join thin plates and thin wall tubing of 14YWT. In the first FSW attempt, a 1.06 cm thick plate of 14YWT (SM13 heat) was successfully rolled at 1000ºC to the target thickness of 0.1 cm with no edge cracking. This achievement is a highlight since previous attempts to roll 14YWT plates have resulted in extensive cracking. For the FSW run, a pin tool being developed by the ORNL FSW Process Development effort was used. The first FSW run successfully produced a bead-on-plate weld in the 0.1 cm thick plate. The quality of the weld zone appears very good with no evidence of large defects such as cavities. The microstructural characterization study of the bead-on-plate weld zone has been initiated to compare the results of the microstructure analysis with those obtained in the reference microstructural analysis of the 14YWT (SM13 heat) that showed ultra-fine grain size of 0.43 μm and a high number density of ~2-5 nm sizes oxygen-enriched nanoclusters.

  5. Aria Sardinia: the on line community joining tradition and innovatiom

    Directory of Open Access Journals (Sweden)

    Fabrizio Lao

    2005-12-01

    Full Text Available The "ARIA Sardinia" project (Network Actions for Italians Abroad has been especially designed to integrate and give value to the network of relationships between public administrations, local socio-economic stakeholders and Italian communities abroad, this goal to be pursued with the support of new technologies and learning approaches emerging within the context of on line interest communities. The general objective of the project is the development of competencies and knowledge, intended to combine specific technical skills with local "territorial knowledge", in a process where the strengthening and the dissemination of these forms of culture come from the prompt use of innovative tools. The main activities of the project are the actions intended to guide and assist entrepreneurs, associations, development projects' partners or promoters in the path of acquisition and dissemination of the competencies which are necessary to the involvement of Italians abroad into the internationalization process of Sardinian economy. ARIA Sardinia was funded by the Italian Foreign Affairs Ministry and the European Social Fund (FSE, within the framework of the National Operational Program for Technical Assistance and System Action (PON ATAS aimed at specific promotion initiatives and fostering of permanent links between Southern Italy economy and Italians living abroad. Keywords: on line community, networking, Italians abroad, Sardinian economy, Sardinia, culture.

  6. OF ALIENATION, ASSOCIATION, AND ADVENTURE: WHY GERMAN FIGHTERS JOIN ISIL

    Directory of Open Access Journals (Sweden)

    Dorle Hellmuth

    2016-03-01

    Full Text Available This article provides an analysis of German foreign fighters who have left for Syria and Iraq since early 2012 and make up the second largest contingent among Western foreign fighters. It draws on statistical information about German foreign fighters, but also uses case studies in an attempt to shed more detailed light on their motivations and why they became radicalized. Drawing on recently released government data, trial documents, and media reports, the article seeks to contribute to new research on the prevailing mechanisms of Jihadi radicalization. To facilitate this kind of comprehensive analysis, McCauley and Moskalenko’s Friction framework is applied to fourteen prominent German fighters, including Denis Cuspert (who served as medium-level ISIL propaganda official, Philip Bergner and Robert Baum (responsible for ISIL suicide attacks in Iraq and Syria, Kreshnik B. and Harun Pashtoon (among the first returning fighters convicted of ISIL membership and other terrorist activities. The article concludes with a discussion of countermeasures used to prevent foreign fighters from leaving Germany, deradicalize those who have started to embrace violent ideas and/or actions, and deal with returning foreign fighters.

  7. Mexico joins the venture: Joint Implementation and Greenhouse Gas Emissions

    Energy Technology Data Exchange (ETDEWEB)

    Imaz, M.; Gay, C.; Friedmann, R.; Goldberg, B.

    1998-11-01

    Joint Implementation (JI) and its pilot phase of Activities Implemented Jointly (AIJ) are envisioned as an economic way of reducing global emissions of greenhouse gases. This paper draws upon the Mexican experience with AIJ to identify Mexican concerns with AIJ/JI and proposed solutions to these. Three approved Mexican AIJ projects (Ilumex, Scolel Te, and Salicornia) are described in detail. The Ilurnex project promotes the use of compact fluorescent lamps in Mexican homes of the States of Jalisco and Nuevo Leon, to reduce electric demand. Scolel Te is a sustainable forest management project in Chiapas. Salicornia examines the potential for carbon sequestration with a Halophyte-based crop irrigated with saline waters in Sonora. These three projects are reviewed to clarify the issues and concerns that Mexico has with AIJ and JI and propose measures to deal with them. These initial Mexican AIJ projects show that there is a need for creation of standard project evaluation procedures, and criteria and institutions to oversee project design, selection, and implementation. Further JI development will be facilitated by national and international clarification of key issues such as additionality criteria, carbon-credit sharing, and valuation of non-GHG environmental and/or social benefits and impacts for AIJ projects. Mexico is concerned that JI funding could negatively impact official development assistance or that OECD countries will use JI to avoid taking significant GHG mitigation actions in their own countries. The lack of carbon credit trading in the AIJ stage must be removed to provide useful experience on how to share carbon credits. National or international guidelines are needed to ensure that a portion of the carbon credits is allocated to Mexico.

  8. Weldability and joining techniques for advanced fossil energy system alloys

    Energy Technology Data Exchange (ETDEWEB)

    Lundin, C.D.; Qiao, C.Y.P.; Liu, W.; Yang, D.; Zhou, G.; Morrison, M. [Univ. of Tennessee, Knoxville, TN (United States)

    1998-05-01

    The efforts represent the concerns for the basic understanding of the weldability and fabricability of the advanced high temperature alloys so necessary to affect increases in the efficiency of the next generation Fossil Energy Power Plants. The effort was divided into three tasks with the first effort dealing with the welding and fabrication behavior of 310HCbN (HR3C), the second task details the studies aimed at understanding the weldability of a newly developed 310TaN high temperature stainless (a modification of 310 stainless) and Task 3 addressed the cladding of austenitic tubing with Iron-Aluminide using the GTAW process. Task 1 consisted of microstructural studies on 310HCbN and the development of a Tube Weldability test which has applications to production welding techniques as well as laboratory weldability assessments. In addition, the evaluation of ex-service 310HCbN which showed fireside erosion and cracking at the attachment weld locations was conducted. Task 2 addressed the behavior of the newly developed 310 TaN modification of standard 310 stainless steel and showed that the weldability was excellent and that the sensitization potential was minimal for normal welding and fabrication conditions. The microstructural evolution during elevated temperature testing was characterized and the second phase particles evolved upon aging were identified. Task 3 details the investigation undertaken to clad 310HCbN tubing with Iron Aluminide and developed welding conditions necessary to provide a crack free cladding. The work showed that both a preheat and a post-heat was necessary for crack free deposits and the effect of a third element on the cracking potential was defined together with the effect of the aluminum level for optimum weldability.

  9. Sinopec and CNOOC Join Hands for Oil Import

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ Sinopec and CNOOC, two of China's big-three oil companies, have set up a joint venture to import crude oil.The joint venture makes CNOOC the fifth largest crude oil importer in China. Following the move, CNOOC is also likely to gain government approval to build a large refinery and market oil products this year, company executives said.

  10. Joining the Game: Living and Learning as an Action Researcher

    Science.gov (United States)

    Hughes, Susan

    2016-01-01

    This study reports on graduate students' thoughts and beliefs about utilizing action research as a means of professional development two years after their graduation from a Master of Arts program in Education. Because many school districts now encourage teachers to engage in self-study and to collect data that informs their instruction, the author…

  11. Elections for staff representatives – Join, commit and vote!

    CERN Multimedia

    Staff Association

    2015-01-01

    The Staff Council is a statutory body representing collectively in the area of employment conditions all CERN staff members (MPE and MPA), as well as the pensioners, former Cernois. The Staff Council is the supreme representative body of the CERN staff and pensioners, which defines the main lines of the policy of the Staff Association. The Staff Council is composed of staff representatives (45 seats to represent staff members, and 5 for representing fellows and associate members), as well as delegates for pensioners (seven positions), designated by GAC-EPA. Every two years, the Council is renewed through elections. Concerning the 45 delegates representing staff members, all departments have a least two seats allocated, one in career paths AA to D and one in career paths E to H. This guarantees a fair distribution of seats among the various organizational units and career paths. The table below, shows the exact number of delegates per department and career paths. Staff members or fellows who want to participa...

  12. Localisation - When Language, Culture and Technology Join Forces

    Directory of Open Access Journals (Sweden)

    Jody Byrne

    2012-08-01

    Full Text Available When you switch on your computer and type up a letter, what language do you see? What about when you visit a website or play a computer game? Does your mobile phone speak your language? Chances are that each of these technological marvels of the modern age communicates with you in your own language. For many of us, this is so commonplace and seamless that we hardly give it a moment's thought but behind the scenes there is a whole industry dedicated to making sure that technology bridges the gap between language and culture without you even noticing.

  13. Chinese and Foreign Oil Giants Join Hands for Petrol Stations

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    @@ The negotiation on the 500 joint venture petrol stations between Sinopec and Royal Dutch/ Shell Group is now under the final stage. Once the negotiation is wound up, the first number of the joint venture petrol stations will be put into operation in Jiangsu Province within three months after the signature of the agreement. The remaining ones will be constructed and put into operation in three years.

  14. ITs in Engineering Education: Joining Efforts Between SPEE and IGIP

    Directory of Open Access Journals (Sweden)

    Alberto Cardoso

    2012-01-01

    Full Text Available The International Society for Engineering Education (IGIP and The Portuguese Society for Engineering Education (SPEE, the first being the oldest European Society for Engineering Education in Europe and the second the very young Society for Engineering Education in Portugal, have been intensifying the collaboration between the two societies as well as the exchange and dissemination of information about their relevant activities, whilst promoting understanding and cooperation between their respective members. One possible way is to create joint working groups, open to the members of both societies, on common topics of interest. In fact, both societies already kicked off this activity. The first initiative happened during the 1st World Engineering Education Flash Week (WEE, Lisbon, 2011. The SPEE-IGIP Flash Moment was a one day event integrated in the main Conference, which was dedicated to “Information & Communication Technologies in Engineering Education”.
    ITs allow the development of different teaching strategies which contribute to enhance the learning outcomes of students. ITs are also particularly suited to develop Life Long Learning tools, in a broad range of Engineering subjects, either open to the general market or oriented to a very specific public.
    Examples of teaching strategies involving ITs have been addressed during the Flash Moment SPEE-IGIP which took place during WEE, and some are described in detail in the present work.

  15. Welding Metallurgy and Processing Issues for Joining of Power Sources

    Energy Technology Data Exchange (ETDEWEB)

    Lienert, Thomas J. [Los Alamos National Laboratory; Reardon, Patrick T. [Los Alamos National Laboratory

    2012-08-14

    Weldability issues with the pertinent alloys have been reviewed and preliminary results of our work on Haynes 25 have been presented. Further results on the mechanical properties and metallography on the EB welds are imminent. Hot-ductility experiments will commence within a few weeks. Aging studies on the effects of heat treatment using the Gleeble are also planned. MST-6 has extensive background in the welding metallurgy of the pertinent alloys. We also have considerable experience with the various welding processes to be used.

  16. Anharmonicity and hydrogen bonding in electrooptic sucrose crystal

    Science.gov (United States)

    Szostak, M. M.; Giermańska, J.

    1990-03-01

    The polarized absorption spectra of the sucrose crystal in the 5300 - 7300 cm -1 region have been measured. The assignments of all the eight OH stretching overtones are proposed and their mechanical anharmonicities are estimated. The discrepancies from the oriented gas model (OGM) in the observed relative band intensities, especially of the -CH vibrations, are assumed to be connected with vibronic couplings enhanced by the helical arrangement of molecules joined by hydrogen bondings. It seems that this kind of interactions might be important for the second harmonic generation (SHG) by the sucrose crystal.

  17. Characteristics of deformation joining of aluminum-stainless steel composite sheet

    Institute of Scientific and Technical Information of China (English)

    李培武; 孙康宁; 李爱民; 李中友; 刘秀忠; 栾新民; 徐秀丽

    2003-01-01

    In order to study the characteristics of deformation joining of aluminum-stainless steel composite sheet,an applied example of this composite sheet was given.The conditions of the composite sheet were discussed,the optical micrographs and scanning electron micrographs were examined by contrast ways of deformation joining and braze joining.Simultaneously the analysis of energy spectrum was also conducted.The results indicate that the deformation joining composite sheet possesses high bonding strength,good corrosion resistance,less inclusions and less microcracks.

  18. Diffusion bonding and brazing of high purity copper for linear collider accelerator structures

    Science.gov (United States)

    Elmer, J. W.; Klingmann, J.; van Bibber, K.

    2001-05-01

    Diffusion bonding and brazing of high purity copper were investigated to develop procedures for joining precision machined copper components for the Next Linear Collider (NLC). Diffusion bonds were made over a range of temperatures from 400 °C to 1000 °C, under two different loading conditions [3.45 kPa (0.5 psi) and 3.45 MPa (500 psi)], and on two different diamond machined surface finishes. Brazes were made using pure silver, pure gold, and gold-nickel alloys, and different heating rates produced by both radiation and induction heating. Braze materials were applied by both physical vapor deposition (PVD) and conventional braze alloy shims. Results of the diffusion bonding experiments showed that bond strengths very near that of the copper base metal could be made at bonding temperatures of 700 °C or higher at 3.45 MPa bonding pressure. At lower temperatures, only partial strength diffusion bonds could be made. At low bonding pressures (3.45 kPa), full strength bonds were made at temperatures of 800 °C and higher, while no bonding (zero strength) was observed at temperatures of 700 °C and lower. Observations of the fracture surfaces of the diffusion bonded samples showed the effects of surface finish on the bonding mechanism. These observations clearly indicate that bonding began by point asperity contact, and flatter surfaces resulted in a higher percentage of bonded area under similar bonding conditions. Results of the brazing experiments indicated that pure silver worked very well for brazing under both conventional and high heating rate scenarios. Similarly, pure silver brazed well for both the PVD layers and the braze alloy shims. The gold and gold-containing brazes had problems, mainly due to the high diffusivity of gold in copper. These problems led to the necessity of overdriving the temperature to ensure melting, the presence of porosity in the joint, and very wide braze joints. Based on the overall findings of this study, a two-step joining method

  19. Diffusion Bonding and Characterization of a Dispersion Strengthened Aluminum Alloy

    Science.gov (United States)

    Cooke, Kavian Omar

    Aluminum metal matrix composites (Al-MMC's) containing silicon carbide or alumina particle reinforcements are used extensively in automotive and aircraft industries. The addition of a reinforcing phase has led to significant improvements in the mechanical properties of these alloys. However, despite substantial improvements in the properties, the lack of a reliable joining method has restricted their full potential. The differences in physical and metallurgical properties between the ceramic phase and the Al-MMC, prevents the successful application of the fusion welding processes, conventionally used for joining monolithic aluminum alloys. Therefore, alternative techniques that prevent microstructural changes in the base metal need to be developed. In this study, the transient liquid phase diffusion bonding and eutectic bonding of a particle reinforced Al 6061-MMC was investigated to identify a method that could control particle segregation within the joint and increase the final joint strength. The results showed that TLP bonding using Ni-foil was possible at 600°C for 10 minutes using a pressure of 0.01 MPa. However, characterization of the bond interface showed a wide particle segregated zone due to the "pushing effect" of the solid/liquid interface during isothermal solidification stage of bonding. The presence of this particle segregated zone was shown to cause low joint strengths. In order to overcome these problems, TLP bonding was performed using electrodeposited coatings of Ni and Ni-Al 2O3 as a way of controlling the volume of eutectic liquid formed at the joint. Theoretical and experimental work showed that the use of thin coatings was successful in reducing the width of the segregated zone formed at the joint and this had the effect of increasing joint shear strength values. Furthermore, lower bonding temperature could also be used as a method of reducing particle segregation and therefore, a Cu-Sn interlayer was used to form a eutectic bond. The

  20. UHV compatible Al to SS joining through electro magnetic forming technique

    Science.gov (United States)

    Prasad, N. K.; Ram, Y.; Sabharwal, T. P.; Pathak, K.; Kumar, M.; Matkar, A. W.; Rajawat, R. K.

    2008-05-01

    Fusion welding, which is the most versatile and widely used method of metallurgical bonding, can be troublesome in certain applications like dissimilar metal joining for Ultra High Vacuum requirements. Welding of Stainless Steel to Aluminum by conventional technique is very difficult due to thermal & metallurgical incompatibility. Consequently a number of non-conventional specialized joining techniques were developed. Joining of SS to Al by Electro Magnetic Forming (EMF) method is an effort in this direction. The paper discusses in detail the joining process, joint design and the results achieved.

  1. RECQ HELICASE RECQL4 PARTICIPATES IN NON-HOMOLOGOUS END JOINING AND INTERACTS WITH THE KU COMPLEX

    DEFF Research Database (Denmark)

    Shamanna, Raghavendra A; Singh, Dharmendra Kumar; Lu, Huiming;

    2014-01-01

    on the activity of DNA-PK, extracts from RECQL4 knockdown cells display reduced end-joining activity on DNA substrates with cohesive and non-cohesive ends. Depletion of RECQL4 also reduced the end joining activity on a GFP reporter plasmid in vivo. Knockdown of RECQL4 increased the sensitivity of cells to γ...

  2. Semiconductors bonds and bands

    CERN Document Server

    Ferry, David K

    2013-01-01

    As we settle into this second decade of the twenty-first century, it is evident that the advances in micro-electronics have truly revolutionized our day-to-day lifestyle. The technology is built upon semiconductors, materials in which the band gap has been engineered for special values suitable to the particular application. This book, written specifically for a one semester course for graduate students, provides a thorough understanding of the key solid state physics of semiconductors. It describes how quantum mechanics gives semiconductors unique properties that enabled the micro-electronics revolution, and sustain the ever-growing importance of this revolution.

  3. Lateral buckling and mechanical stretchability of fractal interconnects partially bonded onto an elastomeric substrate

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Haoran [Department of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058 (China); Departments of Civil and Environmental Engineering and Mechanical Engineering, Center for Engineering and Health, Skin Disease Research Center, Northwestern University, Evanston, Illinois 60208 (United States); Xu, Sheng; Rogers, John A., E-mail: y-huang@northwestern.edu, E-mail: jrogers@illinois.edu [Department of Materials Science and Engineering, Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States); Xu, Renxiao; Huang, Yonggang, E-mail: y-huang@northwestern.edu, E-mail: jrogers@illinois.edu [Departments of Civil and Environmental Engineering and Mechanical Engineering, Center for Engineering and Health, Skin Disease Research Center, Northwestern University, Evanston, Illinois 60208 (United States); Jiang, Jianqun [Department of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058 (China); Zhang, Yihui [Departments of Civil and Environmental Engineering and Mechanical Engineering, Center for Engineering and Health, Skin Disease Research Center, Northwestern University, Evanston, Illinois 60208 (United States); Center for Mechanics and Materials, Tsinghua University, Beijing 100084 (China)

    2015-03-02

    Fractal-inspired designs for interconnects that join rigid, functional devices can ensure mechanical integrity in stretchable electronic systems under extreme deformations. The bonding configuration of such interconnects with the elastomer substrate is crucial to the resulting deformation modes, and therefore the stretchability of the entire system. In this study, both theoretical and experimental analyses are performed for postbuckling of fractal serpentine interconnects partially bonded to the substrate. The deformation behaviors and the elastic stretchability of such systems are systematically explored, and compared to counterparts that are not bonded at all to the substrate.

  4. Common Influence Join

    DEFF Research Database (Denmark)

    Yiu, Man Lung; Mamoulis, Nikos; Karras, Panagiotis

    2008-01-01

    We identify and formalize a novel join operator for two spatial pointsets P and Q. The common influence join (CIJ) returns the pairs of points (p,q),p isin P,q isin Q, such that there exists a location in space, being closer to p than to any other point in P and at the same time closer to q than ......-demand, is very efficient in practice, incurring only slightly higher I/O cost than the theoretical lower bound cost for the problem....

  5. DNA Ligases I and III Cooperate in Alternative Non-Homologous End-Joining in Vertebrates

    OpenAIRE

    Katja Paul; Minli Wang; Emil Mladenov; Alena Bencsik-Theilen; Theresa Bednar; Wenqi Wu; Hiroshi Arakawa; George Iliakis

    2013-01-01

    Biochemical and genetic studies suggest that vertebrates remove double-strand breaks (DSBs) from their genomes predominantly by two non-homologous end joining (NHEJ) pathways. While canonical NHEJ depends on the well characterized activities of DNA-dependent protein kinase (DNA-PK) and LIG4/XRCC4/XLF complexes, the activities and the mechanisms of the alternative, backup NHEJ are less well characterized. Notably, the contribution of LIG1 to alternative NHEJ remains conjectural and although bi...

  6. Effect of continuous and pulsed currents on microstructural evolution of stainless steel joined by TIG welding

    International Nuclear Information System (INIS)

    In this study, AISI 316L series austenitic stainless steel sheets were joined by tungsten inert gas welding method in continuous and pulsed currents. Regarding microstructural investigation and hardness values of weld metal, samples were welded to investigate the effect of current type on grain structures of weld metal. Results showed that samples welded by using pulsed current had considerable different properties compared to the samples welded by using continuous current. While the weld metals of joinings obtained by using continuous current displayed a coarse-grained and columnar structure, weld metals obtained by using pulsed current had a finer-grained structure. It was also found that hardness values of samples, which were welded with continuous and pulsed current, were quite different.

  7. The Developmental Dynamics of Joining a Gang in Adolescence: Patterns and Predictors of Gang Membership.

    Science.gov (United States)

    Gilman, Amanda B; Hill, Karl G; Hawkins, J David; Howell, James C; Kosterman, Rick

    2014-06-01

    Researchers have examined the predictors of adolescent gang membership, finding significant factors in the neighborhood, family, school, peers, and individual domains. However, little is known about whether risk and protective factors differ in predictive salience at different developmental periods. The present study examines predictors of joining a gang, tests whether these factors have different effects at different ages, and whether they differ by gender using the Seattle Social Development Project (SSDP) sample (n=808). By age 19, 173 participants had joined a gang. Using survival analysis, results showed that unique predictors of gang membership onset included living with a gang member, antisocial neighborhood, and antisocial peer influences in the previous year. No time or gender interactions with predictors were statistically significant.

  8. Equitable Strong Edge Coloring of the Joins of Paths and Cycles

    Institute of Scientific and Technical Information of China (English)

    Tao WANG; Ming Ju LIU; De Ming LI

    2012-01-01

    For a proper edge coloring c of a graph G,if the sets of colors of adjacent vertices are distinct,the edge coloring c is called an adjacent strong edge coloring of G.Let ci be the number of edges colored by i.If |ci - cj| ≤ 1 for any two colors i and j,then c is an equitable edge coloring of G.The coloring c is an equitable adjacent strong edge coloring of G if it is both adjacent strong edge coloring and equitable edge coloring.The least number of colors of such a coloring c is called the equitable adjacent strong chromatic index of G.In this paper,we determine the equitable adjacent strong chromatic index of the joins of paths and cycles.Precisely,we show that the equitable adjacent strong chromatic index of the joins of paths and cycles is equal to the maximum degree plus one or two.

  9. Modeling and Testing Miniature Torsion Specimens for SiC Joining Development Studies for Fusion

    Energy Technology Data Exchange (ETDEWEB)

    Henager, Charles H.; Nguyen, Ba Nghiep; Kurtz, Richard J.; Roosendaal, Timothy J.; Borlaug, Brennan A.; Ferraris, Monica; Ventrella, Andrea; Katoh, Yutai

    2015-08-19

    The international fusion community has designed a miniature torsion specimen for neutron irradiation studies of joined SiC and SiC/SiC composite materials. Miniature torsion joints based on this specimen design were fabricated using displacement reactions between Si and TiC to produce Ti3SiC2 + SiC joints with CVD-SiC and tested in torsion-shear prior to and after neutron irradiation. However, many of these miniature torsion specimens fail out-of-plane within the CVD-SiC specimen body, which makes it problematic to assign a shear strength value to the joints and makes it difficult to compare unirradiated and irradiated joint strengths to determine the effects of the irradiation. Finite element elastic damage and elastic-plastic damage models of miniature torsion joints are developed that indicate shear fracture is likely to occur within the body of the joined sample and cause out-of-plane failures for miniature torsion specimens when a certain modulus and strength ratio between the joint material and the joined material exists. The model results are compared and discussed with regard to unirradiated and irradiated joint test data for a variety of joint materials. The unirradiated data includes Ti3SiC2 + SiC/CVD-SiC joints with tailored joint moduli, and includes steel/epoxy and CVD-SiC/epoxy joints. The implications for joint data based on this sample design are discussed.

  10. A Combined Experimental and Numerical Approach to the Laser Joining of Hybrid Polymer - Metal Parts

    Science.gov (United States)

    Rodríguez-Vidal, E.; Lambarri, J.; Soriano, C.; Sanz, C.; Verhaeghe, G.

    A two-step method for the joining of opaque polymer to metal is presented. Firstly, the metal is structured locally on a micro-scale level, to ensure adhesion with the polymeric counterpart. In a second step, the opposite side of the micro-structured metal is irradiated by means of a laser source. The heat thereby created is conducted by the metal and results in the melting of the polymer at the interface. The polymer thereby adheres to the metal and flows into the previously engraved structures, creating an additional mechanical interlock between the two materials. The welding parameters are fine-tuned with the assistance of a finite element model, to ensure the required interface temperature. The method is illustrated using a dual phase steel joined to a fiber-reinforced polyamide. The effect of different microstructures, in particular geometry and cavity aspect ratio, on the joint's tensile-shear mechanical performance is discussed.

  11. A joined multi-metric calibration of river discharge and nitrate loads with different performance measures

    Science.gov (United States)

    Haas, Marcelo B.; Guse, Björn; Pfannerstill, Matthias; Fohrer, Nicola

    2016-05-01

    Hydrological models are useful tools to investigate hydrology and water quality in catchments. The calibration of these models is a crucial step to adapt the model to the catchment conditions, allowing effective simulations of environmental processes. In the model calibration, different performance measures need to be considered to represent different hydrology and water quality conditions in combination. This study presents a joined multi-metric calibration of discharge and nitrate loads simulated with the ecohydrological model SWAT. For this purpose, a calibration approach based on flow duration curves (FDC) is advanced by also considering nitrate duration curves (NDC). Five segments of FDCs and of NDCs are evaluated separately to consider the different phases of hydrograph and nitrograph. To consider both magnitude and dynamics in river discharge and nitrate loads, the Kling-Gupta Efficiency (KGE) is used additionally as a statistical performance metric to achieve a joined multi-variable calibration. The results show that a separate assessment of five different magnitudes improves the calibrated nitrate loads. Subsequently, adequate model runs with good performance for different hydrological conditions both for discharge and nitrate are detected in a joined approach based on FDC, NDC, and KGE. In that manner, plausible results were obtained for discharge and nitrate loads in the same model run. Using a multi-metric performance approach, the simultaneous multi-variable calibration led to a balanced model result for all magnitudes of discharge and nitrate loads.

  12. Generic Multiset Programming with Discrimination-based Joins and Symbolic Cartesian Products

    DEFF Research Database (Denmark)

    Henglein, Fritz; Larsen, Ken Friis

    2011-01-01

    on equivalence discriminators, as an alternative to hash-based and sort-merge joins. Full source code for GMP in Haskell, which is based on generic top-down discrimina- tion (not included), is included for experimentation. We provide illustrative examples whose performance indicates that GMP, even without...... requisite algorithm and data structure engi- neering, is a realistic alternative to SQL even for SQL-expressible queries....

  13. Analytical and experimental evaluation of joining silicon carbide to silicon carbide and silicon nitride to silicon nitride for advanced heat engine applications Phase 2. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Sundberg, G.J.; Vartabedian, A.M.; Wade, J.A.; White, C.S. [Norton Co., Northboro, MA (United States). Advanced Ceramics Div.

    1994-10-01

    The purpose of joining, Phase 2 was to develop joining technologies for HIP`ed Si{sub 3}N{sub 4} with 4wt% Y{sub 2}O{sub 3} (NCX-5101) and for a siliconized SiC (NT230) for various geometries including: butt joins, curved joins and shaft to disk joins. In addition, more extensive mechanical characterization of silicon nitride joins to enhance the predictive capabilities of the analytical/numerical models for structural components in advanced heat engines was provided. Mechanical evaluation were performed by: flexure strength at 22 C and 1,370 C, stress rupture at 1,370 C, high temperature creep, 22 C tensile testing and spin tests. While the silicon nitride joins were produced with sufficient integrity for many applications, the lower join strength would limit its use in the more severe structural applications. Thus, the silicon carbide join quality was deemed unsatisfactory to advance to more complex, curved geometries. The silicon carbide joining methods covered within this contract, although not entirely successful, have emphasized the need to focus future efforts upon ways to obtain a homogeneous, well sintered parent/join interface prior to siliconization. In conclusion, the improved definition of the silicon carbide joining problem obtained by efforts during this contract have provided avenues for future work that could successfully obtain heat engine quality joins.

  14. Tractability results for the Double-Cut-and-Join circular median problem

    CERN Document Server

    Mahmoody-Ghaidary, Ahmad; Stacho, Ladislav

    2011-01-01

    The circular median problem in the Double-Cut-and-Join (DCJ) distance asks to find, for three given genomes, a fourth circular genome that minimizes the sum of the mutual distances with the three other ones. This problem has been shown to be NP-complete. We show here that, if the number of vertices of degree 3 in the breakpoint graph of the three input genomes is fixed, then the problem is tractable

  15. Development of a double beam process for joining aluminum and steel

    Science.gov (United States)

    Frank, Sascha

    2014-02-01

    Multi-material structures pose an attractive option for overcoming some of the central challenges in lightweight design. An exceptionally high potential for creating cost-effective lightweight solutions is attributed to the combination of steel and aluminum. However, these materials are also particularly difficult to join due to their tendency to form intermetallic compounds (IMCs). The growth of these compounds is facilitated by high temperatures and long process times. Due to their high brittleness, IMCs can severely weaken a joint. Thus, it is only possible to create durable steel-aluminum joints when the formation of IMCs can be limited to a non-critical level. To meet this goal, a new joining method has been designed. The method is based on the combination of a continuous wave (pw) and a pulsed laser (pw) source. Laser beams from both sources are superimposed in a common process zone. This makes it possible to apply the advantages of laser brazing to mixed-metal joints without requiring the use of chemical fluxes. The double beam technology was first tested in bead-on-plate experiments using different filler wire materials. Based on the results of these tests, a process for joining steel and aluminum in a double-flanged configuration is now being developed. The double flanged seams are joined using zinc- or aluminum-based filler wires. Microsections of selected seams show that it is possible to achieve good base material wetting while limiting the growth of IMCs to acceptable measures. In addition, the results of tensile tests show that high joint strengths can be achieved.

  16. Development and Characterization of the Bonding and Integration Technologies Needed for Fabricating Silicon Carbide Based Injector Components

    Science.gov (United States)

    Halbig,Michael C.; Singh, Mrityunjay

    2008-01-01

    Advanced ceramic bonding and integration technologies play a critical role in the fabrication and application of silicon carbide based components for a number of aerospace and ground based applications. One such application is a lean direct injector for a turbine engine to achieve low NOx emissions. Ceramic to ceramic diffusion bonding and ceramic to metal brazing technologies are being developed for this injector application. For the diffusion bonding technology, titanium interlayers (coatings and foils) were used to aid in the joining of silicon carbide (SiC) substrates. The influence of such variables as surface finish, interlayer thickness, and processing time were investigated. Electron microprobe analysis was used to identify the reaction formed phases. In the diffusion bonds, an intermediate phase, Ti5Si3Cx, formed that is thermally incompatible in its thermal expansion and caused thermal stresses and cracking during the processing cool-down. Thinner interlayers of pure titanium and/or longer processing times resulted in an optimized microstructure. Tensile tests on the joined materials resulted in strengths of 13-28 MPa depending on the SiC substrate material. Nondestructive evaluation using ultrasonic immersion showed well formed bonds. For the joining technology of brazing Kovar fuel tubes to silicon carbide, preliminary development of the joining approach has begun. Various technical issues and requirements for the injector application are addressed.

  17. Coincident In Vitro Analysis of DNA-PK-Dependent and -Independent Nonhomologous End Joining

    Directory of Open Access Journals (Sweden)

    Cynthia L. Hendrickson

    2010-01-01

    Full Text Available In mammalian cells, DNA double-strand breaks (DSBs are primarily repaired by nonhomologous end joining (NHEJ. The current model suggests that the Ku 70/80 heterodimer binds to DSB ends and recruits DNA-PKcs to form the active DNA-dependent protein kinase, DNA-PK. Subsequently, XRCC4, DNA ligase IV, XLF and most likely, other unidentified components participate in the final DSB ligation step. Therefore, DNA-PK plays a key role in NHEJ due to its structural and regulatory functions that mediate DSB end joining. However, recent studies show that additional DNA-PK-independent NHEJ pathways also exist. Unfortunately, the presence of DNA-PKcs appears to inhibit DNA-PK-independent NHEJ, and in vitro analysis of DNA-PK-independent NHEJ in the presence of the DNA-PKcs protein remains problematic. We have developed an in vitro assay that is preferentially active for DNA-PK-independent DSB repair based solely on its reaction conditions, facilitating coincident differential biochemical analysis of the two pathways. The results indicate the biochemically distinct nature of the end-joining mechanisms represented by the DNA-PK-dependent and -independent NHEJ assays as well as functional differences between the two pathways.

  18. Optimization of Friction Welding Process Parameters for Joining Carbon Steel and Stainless Steel%Optimization of Friction Welding Process Parameters for Joining Carbon Steel and Stainless Steel

    Institute of Scientific and Technical Information of China (English)

    R Paventhan; P R Lakshminarayanan; V Balasubramanian

    2012-01-01

    Friction weIding is a solid state joining process used extensively currently owing to its advantages such as low heat input, high production efficiency, ease of manufacture, and environment friendliness. Materials difficult to be welded by fusion welding processes can be successfully welded by friction welding. An attempt was made to develop an empirical relationship to predict the tensile strength of friction welded AISI 1040 grade medium carbon steel and AISI 304 austenitic stainless steel, incorporating the process parameters such as friction pressure, forging pressure, friction time and forging time, which have great influence on strength of the joints. Response surface methodology was applied to optimize the friction welding process parameters to attain maximum tensile strength of the joint. The maximum tensile strength of 543 MPa could be obtained for the joints fabricated under the welding conditions of friction pressure of 90 MPa, forging pressure of 90 MPa, friction time of 6 s and forging time of 6 s.

  19. Strength of Bond Covenants and Bond Assessment Framework

    Directory of Open Access Journals (Sweden)

    Noel Yahanpath

    2012-06-01

    Full Text Available We examine bond covenants of 29 New Zealand bond issues between 2001 and 2007.Results from the study indicate that protection provided for bondholders is weak and limited.On average, only 2-3 types of covenants are embedded with the issues and only 27% of thesecovenants provide full protection to the bondholders. However, bondholders are not compensated for taking the additional risk. We propose an alternative assessment framework that directly assesses the level of protection offered to bondholders. We calculate thecovenant quality score for the issues and classify them into four levels of protection: very high protection, moderate, low and very low. Recent legislative changes will go some way towards improving investor protection and confidence, but the effect is yet to be seen. This proposed scoring framework can be used by potential investors to complement the traditional credit ratings when making their investment decisions.

  20. Mechanical and microstructural behaviour during bonding of alumina to niobium by liquid state diffusion

    Energy Technology Data Exchange (ETDEWEB)

    Lemus R, J.; Ramirez R, M. I.; Verduzco M, J. A.; Zarate M, J., E-mail: jlruiz@umich.mx [Universidad Michoacana de San Nicolas de Hidalgo, Instituto de Investigacion en Metalurgia y Materiales, Francisco Mujica s/n, 58000 Morelia, Michoacan (Mexico)

    2015-10-15

    The objective of this work was to study various aspects of liquid state diffusion bonding of cylindrical samples of Al{sub 2}O{sub 3} and commercially pure niobium (99.7%) by brazing using a 25 μm thick 70/Cu-30/Zn (wt %) alloy as joining element. Initially, sintering of alumina powder was carried out in order to produce a 7 mm diameter samples at 1550 degrees C by 60 minutes. Joining experiments were carried out on Al{sub 2}O{sub 3}/Cu-Zn/Nb/Cu-Zn/Al{sub 2}O{sub 3} sandwich-like combinations at temperature of 920, 950 and 980 degrees C using vary holding times under Ar. The experimental results show a successful joining of Al{sub 2}O{sub 3} to Nb at 950 and 980 degrees C, however not at 920 degrees C. Joining of Al{sub 2}O{sub 3}/Cu-Zn/Nb/Cu-Zn/Al{sub 2}O{sub 3} occurred by the formation of a homogeneous diffusion zone with no interfacial cracking or porosity at the interface. Scanning electron microscopy (Sem) micrographs show the layer formed in the reaction zone. It was observed that the width of the reaction zone increases with bonding temperature and time. Electron probe microanalysis (Epma) revealed that at any particular bonding temperature, Nb travel into the Cu-Zn joining element forming a circular precipitate phase near to the Al{sub 2}O{sub 3} ceramic. Shears test evaluation show results vary from 57 to 127 MPa in samples joined at 980 degrees C and time vary from 10 to 35 minutes, respectively. (Author)

  1. Diversification, original sin, and international bond portfolios

    OpenAIRE

    John D. Burger; Warnock, Francis E.

    2003-01-01

    This paper has two main goals: to analyze country allocations in international bond portfolios and to describe the development of bond markets around the world. In the primary analysis, we find that country weights in U.S. investors' foreign bond portfolios are determined by the openness of capital accounts and potential diversification benefits. Positions in local-currency-denominated bonds are particularly sensitive to past and prospective volatility of returns. Analysis of reallocations in...

  2. European corporate bond liquidity and yield spreads

    OpenAIRE

    Pukka, Juhamatti

    2010-01-01

    PURPOSE OF THE STUDY The purpose of this study is to provide new empirical evidence on European corporate bond liquidity determinants and the liquidity effect on yield spreads. European corporate bond market is mostly ignored in corporate bond liquidity literature and this thesis’ purpose is to contribute to literature by being among the first papers to estimate liquidity determinants with comprehensive European corporate bond data, covering both investment grade and speculative grade rati...

  3. Effect of moisture, saliva, and blood contamination on the shear bond strength of brackets bonded with a conventional bonding system and self-etched bonding system

    Science.gov (United States)

    Prasad, Mandava; Mohamed, Shamil; Nayak, Krishna; Shetty, Sharath Kumar; Talapaneni, Ashok Kumar

    2014-01-01

    Background: The success of bonding brackets to enamel with resin bonding systems is negatively affected by contamination with oral fluids such as blood and saliva. The new self-etch primer systems combine conditioning and priming agents into a single application, making the procedure more cost effective. Objective: The purpose of the study was to investigate the effect of moisture, saliva and blood contamination on shear bond strength of orthodontic brackets bonded with conventional bonding system and self-etch bonding system. Materials and Methods: Each system was examined under four enamel surface conditions (dry, water, saliva, and blood), and 80 human teeth were divided into two groups with four subgroups each of 10 according to enamel surface condition. Group 1 used conventional bonding system and Group 2 used self-etched bonding system. Subgroups 1a and 2a under dry enamel surface conditions; Subgroups 1b and 2b under moist enamel surface condition; Subgroups 3a and 3b under saliva enamel surface condition and Subgroup 4a and 4b under blood enamel surface condition. Brackets were bonded, and all the samples were then submitted to a shear bond test with a universal testing machine with a cross head speed of 1mm/sec. Results: The results showed that the contamination reduced the shear bond strength of all groups. In self-etch bonding system water and saliva had significantly higher bond strength when compared to other groups. Conclusion: It was concluded that the blood contamination showed lowest bond strength from both bonding systems. Self-etch bonding system resulted in higher bond strength than conventional bonding system under all conditions except the dry enamel surface. PMID:24678210

  4. Transient liquid phase bonding of carbon steel tubes using a Cu interlayer: Characterization and comparison with amorphous Fe–B–Si interlayer bonds

    Energy Technology Data Exchange (ETDEWEB)

    Di Luozzo, Nicolas, E-mail: nicolasdiluozzo@gmail.com [Laboratorio de Sólidos Amorfos, INTECIN, Facultad de Ingeniería, Universidad de Buenos Aires – CONICET, Paseo Colón 850, C1063ACV Buenos Aires (Argentina); Laboratoire des Matériaux et du Génie Physique (CNRS UMR 5628), Grenoble Institute of Technology, MINATEC, Grenoble Cedex 1 (France); Boudard, Michel; Doisneau, Béatrice [Laboratoire des Matériaux et du Génie Physique (CNRS UMR 5628), Grenoble Institute of Technology, MINATEC, Grenoble Cedex 1 (France); Fontana, Marcelo; Arcondo, Bibiana [Laboratorio de Sólidos Amorfos, INTECIN, Facultad de Ingeniería, Universidad de Buenos Aires – CONICET, Paseo Colón 850, C1063ACV Buenos Aires (Argentina)

    2014-12-05

    Highlights: • Cu and Fe–B–Si foils were used as interlayers to bond steel tubes by TLPB process. • The microstructure and mechanical properties were characterized. • In Cu bonded samples, the solidification process was not systematically completed. • When using Cu foils, evidences of epitaxial solidification were observed. • Tensile tests show that Cu and Fe–B–Si bonded samples failed away from the joint. - Abstract: In the present work the transient liquid phase bonding process was performed to join seamless carbon steel tubes using commercially pure Cu interlayers. The structural and mechanical characteristics of the resulting bonds are compared with those achieved using amorphous Fe–B–Si interlayers, under the same process parameters: a holding temperature of 1300 °C, a holding time of 7 min and an applied pressure of 5 MPa. The joined tubes microstructures were characterized by direct observations – scanning electron microscopy – and diffraction techniques – electron backscatter diffraction. Chemical analysis was performed using electron probe microanalysis. Whereas the amorphous Fe-B-Si interlayer leads to a completion of the bonding process over the whole bonding area, the bond performed using a Cu interlayer achieved the completion of the bonding process only partially. As the Cu is a cementite promoter, the amount of cementite coexisting with ferrite grains is higher in the joint region (JR) – corresponding to the higher concentration of Cu – as compared with the heat affected zone (HAZ) and the base metal (BM). An opposite effect is observed when using Fe-B-Si interlayers due to the fact that the cementite is unable to form in Si enriched zones – the microstructure at the JR presents only ferrite grains. Tensile tests show that the joined tubes using Cu or Fe–B–Si interlayers failed away from the bond, at the HAZ, attaining almost the same ultimate tensile strength of the BM, in the as-received condition. Hardness

  5. Transient liquid phase bonding of carbon steel tubes using a Cu interlayer: Characterization and comparison with amorphous Fe–B–Si interlayer bonds

    International Nuclear Information System (INIS)

    Highlights: • Cu and Fe–B–Si foils were used as interlayers to bond steel tubes by TLPB process. • The microstructure and mechanical properties were characterized. • In Cu bonded samples, the solidification process was not systematically completed. • When using Cu foils, evidences of epitaxial solidification were observed. • Tensile tests show that Cu and Fe–B–Si bonded samples failed away from the joint. - Abstract: In the present work the transient liquid phase bonding process was performed to join seamless carbon steel tubes using commercially pure Cu interlayers. The structural and mechanical characteristics of the resulting bonds are compared with those achieved using amorphous Fe–B–Si interlayers, under the same process parameters: a holding temperature of 1300 °C, a holding time of 7 min and an applied pressure of 5 MPa. The joined tubes microstructures were characterized by direct observations – scanning electron microscopy – and diffraction techniques – electron backscatter diffraction. Chemical analysis was performed using electron probe microanalysis. Whereas the amorphous Fe-B-Si interlayer leads to a completion of the bonding process over the whole bonding area, the bond performed using a Cu interlayer achieved the completion of the bonding process only partially. As the Cu is a cementite promoter, the amount of cementite coexisting with ferrite grains is higher in the joint region (JR) – corresponding to the higher concentration of Cu – as compared with the heat affected zone (HAZ) and the base metal (BM). An opposite effect is observed when using Fe-B-Si interlayers due to the fact that the cementite is unable to form in Si enriched zones – the microstructure at the JR presents only ferrite grains. Tensile tests show that the joined tubes using Cu or Fe–B–Si interlayers failed away from the bond, at the HAZ, attaining almost the same ultimate tensile strength of the BM, in the as-received condition. Hardness

  6. Bonds and bands in semiconductors

    CERN Document Server

    Phillips, Jim

    2009-01-01

    This classic work on the basic chemistry and solid state physics of semiconducting materials is now updated and improved with new chapters on crystalline and amorphous semiconductors. Written by two of the world's pioneering materials scientists in the development of semiconductors, this work offers in a single-volume an authoritative treatment for the learning and understanding of what makes perhaps the world's most important engineered materials actually work. Readers will find: --' The essential principles of chemical bonding, electron energy bands and their relationship to conductive and s

  7. Effect of material flow on joint strength in activation spot joining of Al alloy and steel sheets

    Science.gov (United States)

    Watanabe, Goro; Yogo, Yasuhiro; Takao, Hisaaki

    2014-08-01

    A new joining method for dissimilar metal sheets was developed where a rotated consumable rod of Al alloy is pressed onto an Al alloy sheet at the part overlapped with a mild steel sheet. The metal flow in the joining region is increased by the through-hole in the Al sheet and consumable Al rod. The rod creates the joint interface and pads out of the thinly joined parts through pressing. This produces a higher joint strength than that of conventional friction stir spot welding. Measurements of the joint interface showed the presence of a 5-10 nm thick amorphous layer consisting of Al and Mg oxides.

  8. Cut-and-join operators and N=4 super Yang-Mills

    Energy Technology Data Exchange (ETDEWEB)

    Brown, T.W. [DESY, Hamburg (Germany). Theory Group

    2010-02-15

    We show which multi-trace structures are compatible with the symmetrisation of local operators in N=4 super Yang-Mills when they are organised into representations of the global symmetry group. Cut-and-join operators give the non-planar expansion of correlation functions of these operators in the free theory. Using these techniques we find the 1/N corrections to the quarter-BPS operators which remain protected at weak coupling. We also present a new way of counting these chiral ring operators using the Weyl group S{sub N}. (orig.)

  9. Hexacoordinate bonding and aromaticity in silicon phthalocyanine.

    Science.gov (United States)

    Yang, Yang

    2010-12-23

    Si-E bondings in hexacoordinate silicon phthalocyanine were analyzed using bond order (BO), energy partition, atoms in molecules (AIM), electron localization function (ELF), and localized orbital locator (LOL). Bond models were proposed to explain differences between hexacoordinate and tetracoordinate Si-E bondings. Aromaticity of silicon phthalocyanine was investigated using nucleus-independent chemical shift (NICS), harmonic oscillator model of aromaticity (HOMA), conceptual density functional theory (DFT), ring critical point (RCP) descriptors, and delocalization index (DI). Structure, energy, bonding, and aromaticity of tetracoordinate silicon phthalocyanine were studied and compared with hexacoordinate one. PMID:21105726

  10. Copper Wire Bonding Concerns and Best Practices

    Science.gov (United States)

    Chauhan, Preeti; Zhong, Z. W.; Pecht, Michael

    2013-08-01

    Copper wire bonding of microelectronic parts has developed as a means to cut the costs of using the more mature technology of gold wire bonding. However, with this new technology, changes in the bonding processes as well as bonding metallurgy can affect product reliability. This paper discusses the challenges associated with copper wire bonding and the solutions that the industry has been implementing. The paper also provides information to enable customers to conduct qualification and reliability tests on microelectronic packages to facilitate adoption in their target applications.

  11. Personal characteristics and contextual factors that determine "helping," "joining in," and "doing nothing" when witnessing cyberbullying.

    Science.gov (United States)

    Van Cleemput, Katrien; Vandebosch, Heidi; Pabian, Sara

    2014-01-01

    In this article, we investigated several determinants of bystanders' reactive behaviors when confronted with cyberbullying using self-reported data from 2,333 Flemish 9-16 year olds. Structural equation modeling showed that adolescents that had joined in on the cyberbullying were older, had lower levels of empathy and were more likely to have been involved in cyberbullying or traditional bullying as perpetrators. Adolescents who had helped the victim were younger, had higher levels of empathy and were more likely to have been a victim of cyberbullying or traditional bullying in the past months. Adolescents that did nothing when they witnessed cyberbullying, were also older, showed lower levels of empathy and were less likely to have been a victim of traditional bullying. Social anxiety was not related to joining in, helping and remaining passive. In the second part of the analysis, we found that bystanders' passive behavior could be explained in more detail by moral disengagement theory and other contextual factors. In the discussion, the implications of the findings for research on cyberbullying are addressed.

  12. Method for reactively joining materials

    NARCIS (Netherlands)

    Brinkman, H.J.; Duszczyk, J.; Katgerman, L.

    2000-01-01

    Method for reactively joining materials in solid form, such as intermetallic compounds and technical ceramics, wherein: a) a mixed powder is provided in solid form between the materials to be joined; b) at least the powder mixture is locally heated, causing exothermic reactions to take place, whereb

  13. Dynamic Virtual Join Point Dispatch

    NARCIS (Netherlands)

    Bockisch, Christoph; Hauptmann, Michael; Mezini, Mira

    2006-01-01

    Conceptually, join points are points in the execution of a program and advice is late-bound to them. We propose the notion of virtual join points that makes this concept explicit not only at a conceptual, but also at implementation level. In current implementations of aspect-oriented languages, bind

  14. Cooperativity in Surface Bonding and Hydrogen Bonding of Water and Hydroxyl at Metal Surfaces

    DEFF Research Database (Denmark)

    Schiros, T.; Ogasawara, H.; Naslund, L. A.;

    2010-01-01

    of the mixed phase at metal surfaces. The surface bonding can be considered to be similar to accepting a hydrogen bond, and we can thereby apply general cooperativity rules developed for hydrogen-bonded systems. This provides a simple understanding of why water molecules become more strongly bonded...... to the surface upon hydrogen bonding to OH and why the OH surface bonding is instead weakened through hydrogen bonding to water. We extend the application of this simple model to other observed cooperativity effects for pure water adsorption systems and H3O+ on metal surfaces....

  15. Solid State Joining of High Temperature Alloy Tubes for USC and Heat-Exchanger Systems

    Energy Technology Data Exchange (ETDEWEB)

    Bimal Kad

    2011-12-31

    The principal objective of this project was to develop materials enabling joining technologies for use in forward looking heat-exchanger fabrication in Brayton cycle HIPPS, IGCC, FutureGen concepts capable of operating at temperatures in excess of 1000{degree}C as well as conventional technology upgrades via Ultra Super-Critical (USC) Rankine-cycle boilers capable of operating at 760{degree}C (1400F)/38.5MPa (5500psi) steam, while still using coal as the principal fossil fuel. The underlying mission in Rankine, Brayton or Brayton-Rankine, or IGCC combined cycle heat engine is a steady quest to improving operating efficiency while mitigating global environmental concerns. There has been a progressive move to higher overall cycle efficiencies, and in the case of fossil fuels this has accelerated recently in part because of concerns about greenhouse gas emissions, notably CO{sub 2}. For a heat engine, the overall efficiency is closely related to the difference between the highest temperature in the cycle and the lowest temperature. In most cases, efficiency gains are prompted by an increase in the high temperature, and this in turn has led to increasing demands on the materials of construction used in the high temperature end of the systems. Our migration to new advanced Ni-base and Oxide Dispersion Strengthened (ODS) alloys poses significant fabrication challenges, as these materials are not readily weldable or the weld performs poorly in the high temperature creep regime. Thus the joining challenge is two-fold to a) devise appropriate joining methodologies for similar/dissimilar Ni-base and ODS alloys while b) preserving the near baseline creep performance in the welded region. Our program focus is on solid state joining of similar and dissimilar metals/alloys for heat exchanger components currently under consideration for the USC, HIPPS and IGCC power systems. The emphasis is to manipulate the joining methods and variables available to optimize joint creep

  16. 纳米尺度连接技术的研究现状与展望%Research and application of joining technology at nanometer scale

    Institute of Scientific and Technical Information of China (English)

    何鹏; 矫震; 王君; 林铁松

    2013-01-01

    Nanomaterials have been widely applied due to their unique properties. Joining technology at nanometer scale is gradually developed with the popularity of nanomaterials, which has broad application prospects in the fields of electronics, aerospace, biology, and health care. The microscopic effects of nanomaterials were introduced and the current development of joining technology at nanometer scale were reviewed. Solid state bonding, soldering/brazing and fusion welding were mainly discussed. The differences in some phenomena and physical processes between nanoscale and macroscale were analyzed. In addition , the function of molecular dynamics simulation in nano-join-ing field was pointed out. At last, the application prospect of joining technology at nanometer scale was presented.%纳米材料以其特有的结构和性质而得到了广泛应用,纳米尺度的连接技术也随之逐渐发展起来,在电子、宇航、生物医疗等领域具有广阔的应用前景.介绍了纳米材料的微观效应,并综述了纳米尺度连接技术的研究进展,其中主要介绍了纳米固相连接、纳米钎焊和纳米熔化焊的研究现状,分析了在纳米尺度进行材料连接时,一些现象和物理过程与宏观连接时的区别,同时指出了分子动力学方法在纳米连接领域的作用,最后对纳米尺度连接技术的应用前景进行了展望.

  17. Lif1 SUMOylation and its role in non-homologous end-joining

    OpenAIRE

    Vigasova, Dana; Sarangi, Prabha; Kolesar, Peter; Vlasáková, Danuša; Slezakova, Zuzana; Altmannova, Veronika; Nikulenkov, Fedor; Anrather, Dorothea; Gith, Rainer; Zhao, Xiaolan; Chovanec, Miroslav; Krejci, Lumir

    2013-01-01

    Non-homologous end-joining (NHEJ) repairs DNA double-strand breaks by tethering and ligating the two DNA ends. The mechanisms regulating NHEJ efficiency and interplay between its components are not fully understood. Here, we identify and characterize the SUMOylation of budding yeast Lif1 protein, which is required for the ligation step in NHEJ. We show that Lif1 SUMOylation occurs throughout the cell cycle and requires the Siz SUMO ligases. Single-strand DNA, but not double-strand DNA or the ...

  18. An innovative platform for quick and flexible joining of assorted DNA fragments.

    Science.gov (United States)

    De Paoli, Henrique Cestari; Tuskan, Gerald A; Yang, Xiaohan

    2016-01-01

    Successful synthetic biology efforts rely on conceptual and experimental designs in combination with testing of multi-gene constructs. Despite recent progresses, several limitations still hinder the ability to flexibly assemble and collectively share different types of DNA segments. Here, we describe an advanced system for joining DNA fragments from a universal library that automatically maintains open reading frames (ORFs) and does not require linkers, adaptors, sequence homology, amplification or mutation (domestication) of fragments in order to work properly. This system, which is enhanced by a unique buffer formulation, provides unforeseen capabilities for testing, and sharing, complex multi-gene circuitry assembled from different DNA fragments. PMID:26758940

  19. Joining Forces

    DEFF Research Database (Denmark)

    Christiansen, Anne Mette

    2013-01-01

    companies have over the last 23 years embraced the concept of strategic CSR and are increasingly engaging in cross-sector partnerships as part of their CSR strategy. The partnerships take different forms both in regards to number of partners, focus areas and level of strategic engagement. In the article......The interest in Corporate Social Responsibility (CSR) has grown dramatically over the last three years in Greenland. A vast geographical area with a tiny population, Greenland has recently obtained self-government status and is going through a rapid development economically and socially...

  20. Joining Forces

    Science.gov (United States)

    Sawchuk, Stephen; Sparks, Sarah D.; Cavanagh, Sean; Samuels, Christina A.

    2011-01-01

    A mantra in recent years has been to blame the teachers' unions for many of the problems that beset public education. Americans only need look at Wisconsin, where the governor and lawmakers pushed through legislation curtailing the collective bargaining rights of teachers and other public employees. This special report examines the attempts by a…

  1. Emergence and oscillation of cosmic space by joining M1-branes

    OpenAIRE

    Sepehri, Alireza; Rahaman, Farook; Capozziello, Salvatore; Ali, Ahmed Farag; Pradhan, Anirudh(Department of Mathematics, Institute of Applied Sciences & Humanities, GLA University, Mathura, U.P., 281 406, India)

    2016-01-01

    Recently, it has been proposed by Padmanabhan that the difference between the number of degrees of freedom on the boundary surface and the number of degrees of freedom in a bulk region leads to the expansion of the universe. Now, a natural question arises, how this model could explain the oscillation of universe between contraction and expansion branches? We try to address this issue in the framework of BIonic system. In this model, $M0$-branes join to each other and give rise to a pair of $M...

  2. Group-living herbivores weigh up food availability and dominance status when making patch-joining decisions.

    Directory of Open Access Journals (Sweden)

    Keenan Stears

    Full Text Available Two key factors that influence the foraging behaviour of group-living herbivores are food availability and individual dominance status. Yet, how the combination of these factors influences the patch-joining decisions of individuals foraging within groups has scarcely been explored. To address this, we focused on the patch-joining decisions of group-living domestic goats (Capra hircus. When individuals were tested against the top four ranked goats of the herd, we found that at patches with low food availability they avoided these dominant patch-holders and only joined subordinates (i.e. costs outweighed benefits. However, as the amount of food increased, the avoidance of the top ranked individuals declined. Specifically, goats shifted and joined the patch of an individual one dominance rank higher than the previous dominant patch holder when the initial quantity of food in the new patch was twice that of the lower ranking individual's patch (i.e. benefits outweighed costs. In contrast, when individuals chose between patches held by dominant goats, other than the top four ranked goats, and subordinate individuals, we found that they equally joined the dominant and subordinate patch-holders. This joining was irrespective of the dominance gap, absolute rank of the dominant patch-holder, sex or food availability (i.e. benefits outweighed costs. Ultimately, our results highlight that herbivores weigh up the costs and benefits of both food availability and patch-holder dominance status when making patch-joining decisions. Furthermore, as the initial quantity of food increases, food availability becomes more important than dominance with regard to influencing patch-joining decisions.

  3. Environmentally friendly joining of tubes by their ends

    DEFF Research Database (Denmark)

    Silva, Carlos M.A.; Nielsen, Chris Valentin; Alves, Luis M.;

    2015-01-01

    This paper proposes an environmentally friendly joining process for connecting tubes by their ends that has the potential to replace current solutions based on fastened, crimped, welded, brazed or adhesive bonded joints. The process is based on a new type of tubular lap joint produced by local...... plastic instability and compression beading that has a substantial overlap with the counterfacing surfaces of the mating tubes to be joined. The presentation combines independent characterization of the materials, experimentation and numerical simulation of the process in order to identify the modes...

  4. Systems of joining undefitting in range of temperature 73 K-543 K between treated PTFE with metallic sodium and metals

    International Nuclear Information System (INIS)

    The systems of joining undefitting of the pieces of PTFE (Teflon) with the metals and the method of their achievement are described. These consist in joining through soldering with adhesive X60 or EP 310, made by HBM-Germany. This adhesive is coated on joining surface of the pieces, processed at a certain roughness in a layer of a calculated thickness. To achieve this joining the PTFE surface was subjected to a special treatment, which was achieved with metallic sodium. Following the joining by specific procedures of soldering, concomitant with plastic deformation of the metal, undefitting systems with unique characteristics and properties have resulted. The tests to which these systems were subjected have shown the tightness of the joining to high vacuum (∼ 10-9 torr) in conditions of repeated thermal shocks, in the temperature range of 73 K - 543 K. Superior mechanical characteristics were obtained and by the tests achieved according with the specific ASTM and DIN standards. Special characteristics of these systems made it possible their using in high technology: cryogenics, physics of the low temperatures, cosmic space, nuclear power plants, electrotechnology, chemical industry, the high vacuum technique, superinsulation, car industry and so on. (authors)

  5. Silver- and gold-mediated nucleobase bonding.

    Science.gov (United States)

    Acioli, Paulo H; Srinivas, Sudha

    2014-08-01

    We report the results of a density functional theory investigation of the bonding of nucleobases mediated by silver and gold atoms in the gas phase. Our calculations use the Becke exchange and Perdew-Wang correlation functional (BPW91) combined with the Stuttgart effective core potentials to represent the valence electrons of gold, silver, and platinum, and the all-electron DGTZVP basis set for C, H, N, and O. This combination was chosen based on tests on the metal atoms and tautomers of adenine, cytosine, and guanine. To establish a benchmark to understand the metal-mediated bonding, we calculated the binding energy of each of the base pairs in their canonical forms. Our calculations show rather strong bonds between the Watson-Crick base pairs when compared with typical values for N-H-N and N-H-O hydrogen bonds. The neutral metal atoms tend to bond near the nitrogen atoms. The effect of the metal atoms on the bonding of nucleobases differs depending on whether or not the metal atoms bond to one of the hydrogen-bonding sites. When the silver or gold atoms bond to a non-hydrogen-bonding site, the effect is a slight enhancement of the cytosine-guanine bonding, but there is almost no effect on the adenine-thymine pairing. The metal atoms can block one of the hydrogen-bonding sites, thus preventing the normal cytosine-guanine and adenine-thymine pairings. We also find that both silver and gold can bond to consecutive guanines in a similar fashion to platinum, albeit with a significantly lower binding energy.

  6. FMEA and FTA Analyses of the Adhesive Joining Process using Electrically Conductive Adhesives

    Directory of Open Access Journals (Sweden)

    E. Povolotskaya

    2012-01-01

    Full Text Available This paper introduces a formulation of appropriate risk estimation methods that can be used for improving of processes in the electronics area. Two risk assessment methods have been chosen with regard to the specifics of adhesive joining based on electrically conductive adhesives. The paper provides a combination of a failure mode and effect analysis (FMEA and fault tree analysis (FTA for optimizing of the joining process. Typical features and failures of the process are identified. Critical operations are found and actions for avoiding failures in these actions are proposed. A fault treehas been applied to the process in order to get more precise information about the steps and operations in the process, and the relations between these operations. The fault tree identifies potential failures of the process. Then the effects of the failures have been estimated by the failure mode and effect analysis method. All major differences between failure mode and effect analysis and fault tree analysis are defined and there is a discussion about how to use the two techniquescomplement each other and achieve more efficient results.

  7. Main Chain Noncentrosymmetric Hydrogen Bonded Macromolecules Incorporating Aniline, Alkanol, and Alkanoic Acid Hydrogen Bond Donors

    OpenAIRE

    Jeremy R. Wolf

    2014-01-01

    The syntheses and characterization of three noncentrosymmetric main chain hydrogen bonded macromolecules which incorporate aniline, alkanoic acid, and alkanol hydrogen bond donor units are reported. These macromolecules participate in weak intermolecular hydrogen bonding as demonstrated using attenuated total reflectance (ATR) FTIR. The phase transitions of these macromolecules depend on the identity of the hydrogen bond donor.

  8. Hermetic glass frit packaging in air and vacuum with localized laser joining

    Science.gov (United States)

    Lorenz, N.; Millar, S.; Desmulliez, M.; Hand, D. P.

    2011-04-01

    Glass frit packaging is a simple and robust method used for hermetic sealing of micro-devices. Conventional glass frit packaging processes rely on furnace heating where the entire package is heated to elevated temperatures, hence restricting the use of temperature-sensitive materials inside the package and generating problems in multi-stage packaging processes. The use of a laser as an alternative heat source offers the possibility of highly localized heating where the heat-input can be restricted to the joining area only. In this paper the clear benefits of combining glass frit packaging and localized laser heating are demonstrated. Two novel laser-based glass frit packaging processes for sealing of leadless chip carrier (LCC) packages in both air and vacuum have been developed. Full hermetic seals according to MIL-STD-883G are achieved in high yield processes where the temperature in the centre of the device is kept at least 230 °C below the temperature in the joining region.

  9. Joining of AZ31 and AZ91 Mg alloys by friction stir welding

    Directory of Open Access Journals (Sweden)

    B. Ratna Sunil

    2015-12-01

    Full Text Available Two dissimilar magnesium (Mg alloy sheets, one with low aluminium (AZ31 and another with high aluminium (AZ91 content, were successfully joined by friction stir welding (FSW. The effect of process parameters on the formation of hot cracks was investigated. A sound metallurgical joint was obtained at optimized process parameters (1400 rpm with 25 mm/min feed which contained fine grains and distributed β (Mg17Al12 phase within the nugget zone. An increasing trend in the hardness measurements has also confirmed more amount of dissolution of aluminium within the nugget zone. A sharp interface between nugget zone and thermo mechanical affected zone (TMAZ was clearly noticed at the AZ31 Mg alloy side (advancing but not on the AZ91 Mg alloy side (retreating. From the results it can be concluded that FSW can be effectively used to join dissimilar metals, particularly difficult to process metals such as Mg alloys, and hot cracking can be completely eliminated by choosing appropriate process parameters to achieve sound joint.

  10. Fracture strength of different soldered and welded orthodontic joining configurations with and without filling material

    Directory of Open Access Journals (Sweden)

    Jens Johannes Bock

    2008-10-01

    Full Text Available The aim of this study was to compare the mechanical strength of different joints made by conventional brazing, TIG and laser welding with and without filling material. Five standardized joining configurations of orthodontic wire in spring hard quality were used: round, cross, 3 mm length, 9 mm length and 7 mm to orthodontic band. The joints were made by five different methods: brazing, tungsten inert gas (TIG and laser welding with and without filling material. For the original orthodontic wire and for each kind of joint configuration or connecting method 10 specimens were carefully produced, totalizing 240. The fracture strengths were measured with a universal testing machine (Zwick 005. Data were analyzed by ANOVA (p=0.05 and Bonferroni post hoc test (p=0.05. In all cases, brazing joints were ruptured on a low level of fracture strength (186-407 N. Significant differences between brazing and TIG or laser welding (p<0.05, Bonferroni post hoc test were found in each joint configuration. The highest fracture strength means were observed for laser welding with filling material and 3 mm joint length (998 N. Using filling materials, there was a clear tendency to higher mean values of fracture strength in TIG and laser welding. However, statistically significant differences were found only in the 9-mm long joints (p<0.05, Bonferroni post hoc test. In conclusion, the fracture strength of welded joints was positively influenced by the additional use of filling material. TIG welding was comparable to laser welding except for the impossibility of joining orthodontic wire with orthodontic band.

  11. Constructing Models in Teaching of Chemical Bonds: Ionic Bond, Covalent Bond, Double and Triple Bonds, Hydrogen Bond and Molecular Geometry

    Science.gov (United States)

    Uce, Musa

    2015-01-01

    Studies in chemistry education show that chemistry topics are considered as abstract, complicated and hard to understand by students. For this reason, it is important to develop new materials and use them in classes for better understanding of abstract concepts. Moving from this point, a student-centered research guided by a teacher was conducted…

  12. Three dimensional geometrical and material nonlinear finite element analysis of adhesively bonded joints for marine structures

    OpenAIRE

    Sampathkumar, Narasimhan

    2005-01-01

    The use of adhesive bonding as a structural joining method has been gaining recognition in marine industry in recent years, though it has been widely adopted in other fields such as aerospace, automobiles, trains and in civil constructions. The type of materials used and design practices followed in marine structures are different from what is applied in other disciplines. Therefore new research approaches are required and recent novel ideas are ex- plored in the context of app...

  13. Effect of new adhesion promoter and mechanical interlocking on bonding strength in metal-polymer composites

    Science.gov (United States)

    Schuberth, A.; Göring, M.; Lindner, T.; Töberling, G.; Puschmann, M.; Riedel, F.; Scharf, I.; Schreiter, K.; Spange, S.; Lampke, T.

    2016-03-01

    There are various opportunities to improve the adhesion between polymer and metal in metal-plastic composites. The addition of a bonding agent which reacts with both joining components at the interfaces of the composite can enhance the bonding strength. An alternative method for the adjustment of interfaces in metal-plastic composites is the specific surface structuring of the joining partners in order to exploit the mechanical interlock effect. In this study the potential of using an adhesion promoter based on twin polymerization for metal-plastic composites in combination with different methods of mechanical surface treatment is evaluated by using the tensile shear test. It is shown that the new adhesion promoter has a major effect when applied on smooth metal surfaces. A combination of both mechanical and chemical surface treatment of the metal part is mostly just as effective as the application of only one of these surface treatment methods.

  14. Diffusion bonding

    Science.gov (United States)

    Anderson, Robert C.

    1976-06-22

    1. A method for joining beryllium to beryllium by diffusion bonding, comprising the steps of coating at least one surface portion of at least two beryllium pieces with nickel, positioning a coated surface portion in a contiguous relationship with an other surface portion, subjecting the contiguously disposed surface portions to an environment having an atmosphere at a pressure lower than ambient pressure, applying a force upon the beryllium pieces for causing the contiguous surface portions to abut against each other, heating the contiguous surface portions to a maximum temperature less than the melting temperature of the beryllium, substantially uniformly decreasing the applied force while increasing the temperature after attaining a temperature substantially above room temperature, and maintaining a portion of the applied force at a temperature corresponding to about maximum temperature for a duration sufficient to effect the diffusion bond between the contiguous surface portions.

  15. Sunspots and Inflation-indexed Bonds

    OpenAIRE

    Minwook KANG

    2014-01-01

    An economy with incomplete ?nancial markets, as described by Cass (1989), typically has in?ation volatility driven by sunspots. The purpose of this paper is to investigate how the introduction of in?ation- indexed bonds to the ?Cass?economy in?uences a monetary market, an indexed bond market, and welfare. The introduction of indexed bonds is considered a sunspot-stabilizing policy. However, this introduction unrealistically causes the complete shutdown of monetary markets. This problem can be...

  16. Upper bound analysis for deep tunnel face with joined failure mechanism of translation and rotation

    Institute of Scientific and Technical Information of China (English)

    许敬叔; 杜佃春; 杨子汉

    2015-01-01

    A joined failure mechanism of translation and rotation was proposed for the stability analysis of deep tunnel face, and the upper bound solution of supporting force of deep tunnel was calculated under pore water pressure. The calculations were based on limit analysis method of upper bound theory, with the employment of non-associated Mohr-Coulomb flow rule. Nonlinear failure criterion was adopted. Optimized analysis was conducted for the effects of the tunnel depth, pore water pressure coefficient, the initial cohesive force and nonlinear coefficient on supporting force. The upper bound solutions are obtained by optimum method. Results are listed and compared with the previously published solutions for the verification of correctness and effectiveness. The failure shapes are presented, and results are discussed for different pore water pressure coefficients and nonlinear coefficients of tunnel face.

  17. Enhancing project-oriented learning by joining communities of practice and opening spaces for relatedness

    Science.gov (United States)

    Pascual, R.

    2010-03-01

    This article describes an extension to project-oriented learning to increase social construction of knowledge and learning. The focus is on: (a) maximising opportunities for students to share their knowledge with practitioners by joining communities of practice, and (b) increasing their intrinsic motivation by creating conditions for student's relatedness. The case study considers a last year capstone course in Mechanical Engineering. The work addresses innovative practices of active learning and beyond project-oriented learning through: (a) the development of a web-based decision support system, (b) meetings between the communities of students, maintenance engineers and academics, and (c) new off-campus group instances. The author hypothesises that this multi-modal approach increases deep learning and social impact of the educational process. Surveys to the actors support a successful achievement of the educational goals. The methodology can easily be extended to further improve the learning process.

  18. Effects of pyrolysis temperature and fillers on joining of ceramics via silicone resin

    Institute of Scientific and Technical Information of China (English)

    SUO Jun; CHEN Zhao-hui; ZHENG Wen-wei; HAN Wei-min

    2005-01-01

    The joining of graphite, ceramic SiC and Cf/SiC composites via preceramic silicone resin(SR) at high temperature (800-1400℃) was studied. The curing and pyrolysis process of SR, pyrolysis temperature, inert and active fillers were especially discussed. The results show that the curing process of SR was accomplished by consuming Si-OH. The temperature of 1200℃ is the appropriate treating temperature for graphite and SiC ceramic, and the temperature of 1400℃ is suitable for Cf/SiC composites. Inert filler SiC powder(5%, mass fraction) has much positive influence on the shear strength of the joints. Active filler nano Ai, Si powder can greatly improve the properties of the joints treated at high temperature. The improvement is over 700%.

  19. Cut-and-join description of generalized Brezin-Gross-Witten model

    CERN Document Server

    Alexandrov, Alexander

    2016-01-01

    We investigate the Brezin-Gross-Witten model, a tau-function of the KdV hierarchy, and its natural one-parameter deformation, the generalized Brezin-Gross-Witten tau-function. In particular, we derive the Virasoro constraints, which completely specify the partition function. We solve them in terms of the cut-and-join operator. The Virasoro constraints lead to the loop equations, which we solve in terms of the correlation functions. Explicit expressions for the coefficients of the tau-function and the free energy are derived, and a compact formula for the genus zero contribution is conjectured. A family of polynomial solutions of the KdV hierarchy, given by the Schur functions, is obtained for the half-integer values of the parameter. The quantum spectral curve and its classical limit are discussed.

  20. Dissimilar Laser Joining of NiTi SMA and MP35N Wires

    Science.gov (United States)

    Panton, Boyd; Pequegnat, Andrew; Zhou, Y. Norman

    2014-07-01

    The laser welding of NiTi alloy wire to MP35N wire was investigated to improve the understanding of dissimilar materials joining of NiTi shape memory alloys (SMAs), facilitating their future application in novel devices. Both positioning of the laser beam with respect to the joint's centerline and laser peak power were found to be critical variables affecting the physical and thermomechanical properties of the welded joint. Positioning of the laser beam was used to control the weld pool composition, while the laser beam intensity affected the pool size and mixing. These variables were shown to greatly affect hardness and susceptibility to cracking in the fusion zone, which heavily impacted the weld strength. With a lower peak power and the laser positioned over the MP35N wire, butt-welded wire joints were achieved with the ultimate load of 66 pct of the NiTi wire breaking load.

  1. ATRX loss promotes tumor growth and impairs nonhomologous end joining DNA repair in glioma.

    Science.gov (United States)

    Koschmann, Carl; Calinescu, Anda-Alexandra; Nunez, Felipe J; Mackay, Alan; Fazal-Salom, Janet; Thomas, Daniel; Mendez, Flor; Kamran, Neha; Dzaman, Marta; Mulpuri, Lakshman; Krasinkiewicz, Johnathon; Doherty, Robert; Lemons, Rosemary; Brosnan-Cashman, Jacqueline A; Li, Youping; Roh, Soyeon; Zhao, Lili; Appelman, Henry; Ferguson, David; Gorbunova, Vera; Meeker, Alan; Jones, Chris; Lowenstein, Pedro R; Castro, Maria G

    2016-03-01

    Recent work in human glioblastoma (GBM) has documented recurrent mutations in the histone chaperone protein ATRX. We developed an animal model of ATRX-deficient GBM and showed that loss of ATRX reduces median survival and increases genetic instability. Further, analysis of genome-wide data for human gliomas showed that ATRX mutation is associated with increased mutation rate at the single-nucleotide variant (SNV) level. In mouse tumors, ATRX deficiency impairs nonhomologous end joining and increases sensitivity to DNA-damaging agents that induce double-stranded DNA breaks. We propose that ATRX loss results in a genetically unstable tumor, which is more aggressive when left untreated but is more responsive to double-stranded DNA-damaging agents, resulting in improved overall survival. PMID:26936505

  2. Green and social bonds - A promising tool

    International Nuclear Information System (INIS)

    Issues of green bonds, socially responsible bonds and climate bonds are on the rise. Novethic estimates that some Euro 5 billion in such bonds has been issued since the start of 2013 by development banks, the main issuers of this type of debt. The figure is equal to over half of their total issues since 2007. Including local authorities, corporations and banks, a total Euro 8 billion of these bonds has been issued thus far in 2013. Given the size of the bond market, which the OECD estimated at Euro 95,000 billion in 2011, green and social bonds are still something of a niche but have strong growth potential. A number of large issues, from Euro 500 million to Euro 1 billion, were announced at the end of the year. Unlike conventional bonds, green and social bonds are not intended to finance all the activities of the issuer or refinance its debt. They serve instead to finance specific projects, such as producing renewable energy or adapting to climate change, the risk of which is shouldered by the issuer. This makes them an innovative instrument, used to earmark investments in projects with a direct environmental or social benefit rather than simply on the basis of the issuer's sustainable development policy. With financing being sought for the ecological transition, green and social bonds are promising instruments, sketching out at global level the shape of tools adapted to the financing of a green economy. On the strength of these advantages, the interest of responsible investors - the main target of green and social bond issuers - is growing fast. Judging by issuer press releases and the most commonly used currencies, the main subscribers today are US investors, among them CalSTRS and fund managers like Calvert Investment Management and Trillium Asset Management. European asset owners are also starting to focus on green and social bonds. A Novethic survey shows that 13% of them have already subscribed to such an issue or plan to do so. The present study

  3. Embedded Heaters for Joining or Separating Plastic Parts

    Science.gov (United States)

    Bryant, Melvin A., III

    2004-01-01

    A proposed thermal-bonding technique would make it possible to join or separate thermoplastic parts quickly and efficiently. The technique would eliminate the need for conventional welding or for such conventional fastening components as bolted flanges or interlocking hooks. The technique could be particularly useful in the sign industry (in which large quantities of thermoplastics are used) or could be used to join plastic pipes. A thin sheet of a suitable electrically conductive material would be formed to fit between two thermoplastic parts to be joined (see figure). The electrically conductive sheet and the two parts would be put together tightly, then an electrical current would be sent through the conductor to heat the thermoplastic locally. The magnitude of the current and the heating time would be chosen to generate just enough heat to cause the thermoplastic to adhere to both sides of the electrically conductive sheet. Optionally, the electrically conductive sheet could contain many small holes to provide purchase or to increase electrical resistance to facilitate the generation of heat. After thermal bonding, the electrically conductive sheet remains as an integral part of the structure. If necessary, the electrically conductive sheet can be reheated later to separate the joined thermoplastic parts.

  4. Halogen bonding origin properties and applications

    International Nuclear Information System (INIS)

    σ-hole bonding represents an unusual and novel type of noncovalent interactions in which atom with σ- hole interacts with Lewis base such as an electronegative atom (oxygen, nitrogen, …) or aromatic systems. This bonding is of electrostatic nature since the σ-hole bears a positive charge. Dispersion energy forms equally important energy term what is due to the fact that two heavy atoms (e.g. halogen and oxygen) having high polarizability lie close together (the respective distance is typically shorter than the sum of van der Waals radii). Among different types of σ-hole bondings the halogen bonding is by far the most known but chalcogen and pnictogen bondings are important as well

  5. Halogen bonding origin properties and applications

    Energy Technology Data Exchange (ETDEWEB)

    Hobza, Pavel [Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, 166 10 Prague (Czech Republic); Regional Center of Advanced Technologies and Materials, Department of Physical Chemistry, Palacky University, 77146 Olomouc (Czech Republic)

    2015-12-31

    σ-hole bonding represents an unusual and novel type of noncovalent interactions in which atom with σ- hole interacts with Lewis base such as an electronegative atom (oxygen, nitrogen, …) or aromatic systems. This bonding is of electrostatic nature since the σ-hole bears a positive charge. Dispersion energy forms equally important energy term what is due to the fact that two heavy atoms (e.g. halogen and oxygen) having high polarizability lie close together (the respective distance is typically shorter than the sum of van der Waals radii). Among different types of σ-hole bondings the halogen bonding is by far the most known but chalcogen and pnictogen bondings are important as well.

  6. Join Operations in Temporal Databases

    DEFF Research Database (Denmark)

    Gao, D.; Jensen, Christian Søndergaard; Snodgrass, R.T.;

    2005-01-01

    , if any, comparison of the various operators. We then address evaluation algorithms, comparing the applicability of various algorithms to the temporal join operators and describing a performance study involving algorithms for one important operator, the temporal equijoin. Our focus, with respect......Joins are arguably the most important relational operators. Poor implementations are tantamount to computing the Cartesian product of the input relations. In a temporal database, the problem is more acute for two reasons. First, conventional techniques are designed for the evaluation of joins...... with equality predicates rather than the inequality predicates prevalent in valid-time queries. Second, the presence of temporally varying data dramatically increases the size of a database. These factors indicate that specialized techniques are needed to efficiently evaluate temporal joins. We address...

  7. Blind-date Conversation Joining

    Directory of Open Access Journals (Sweden)

    Luca Cesari

    2013-07-01

    Full Text Available We focus on a form of joining conversations among multiple parties in service-oriented applications where a client may asynchronously join an existing conversation without need to know in advance any information about it. More specifically, we show how the correlation mechanism provided by orchestration languages enables a form of conversation joining that is completely transparent to clients and that we call 'blind-date joining'. We provide an implementation of this strategy by using the standard orchestration language WS-BPEL. We then present its formal semantics by resorting to COWS, a process calculus specifically designed for modelling service-oriented applications. We illustrate our approach by means of a simple, but realistic, case study from the online games domain.

  8. Analytical and Experimental Evaluation of Joining Silicon Carbide to Silicon Carbide and Silicon Nitride to Silicon Nitride for Advanced Heat Engine Applications Phase II

    Energy Technology Data Exchange (ETDEWEB)

    Sundberg, G.J.

    1994-01-01

    Techniques were developed to produce reliable silicon nitride to silicon nitride (NCX-5101) curved joins which were used to manufacture spin test specimens as a proof of concept to simulate parts such as a simple rotor. Specimens were machined from the curved joins to measure the following properties of the join interlayer: tensile strength, shear strength, 22 C flexure strength and 1370 C flexure strength. In parallel, extensive silicon nitride tensile creep evaluation of planar butt joins provided a sufficient data base to develop models with accurate predictive capability for different geometries. Analytical models applied satisfactorily to the silicon nitride joins were Norton's Law for creep strain, a modified Norton's Law internal variable model and the Monkman-Grant relationship for failure modeling. The Theta Projection method was less successful. Attempts were also made to develop planar butt joins of siliconized silicon carbide (NT230).

  9. On the Performance and Pruning Power of Different Join Enumeration Strategies

    OpenAIRE

    Viktor Leis

    2016-01-01

    To find the optimal join order two different generative join enumeration strategies have been proposed. The most commonly used one is dynamic programming which proceeds bottom-up. The alternative is top down enumeration with memoization. For both strategies algorithms exist that enumerate only solutions without cartesian products, which is a commonly used heuristics. With top-down enumeration it is possible to further improve optimization time by pruning the search space while still obtaining...

  10. The Nature of the Hydrogen Bond Outline of a Comprehensive Hydrogen Bond Theory

    CERN Document Server

    Gilli, Gastone

    2009-01-01

    Hydrogen bond (H-bond) effects are known: it makes sea water liquid, joins cellulose microfibrils in trees, shapes DNA into genes and polypeptide chains into wool, hair, muscles or enzymes. Its true nature is less known and we may still wonder why O-H...O bond energies range from less than 1 to more than 30 kcal/mol without apparent reason. This H-bond puzzle is re-examined here from its very beginning and presented as an inclusive compilation of experimental H-bond energies andgeometries.New concepts emerge from this analysis: new classes of systematically strong H-bonds (CAHBs and RAHBs: cha

  11. Desperately seeking fusion: on 'joined-up thinking', 'holistic practice' and the new economy of welfare professional power.

    Science.gov (United States)

    Allen, Chris

    2003-06-01

    This paper argues that social welfare research on joined-up thinking is underpinned by two theses. The 'systemic move' thesis suggests that joined-up thinking is needed to fill gaps in welfare service provision arising from a lack of interorganizational co-ordination. The 'epistemological move' thesis advises that joined-up thinking is needed to overcome deficiencies in the institutional division and distribution of welfare knowledge. Both theses macro-systematize blame for previous social welfare failures, and both are teleological because they present joined-up thinking as a progressive solution that results in a more effective (and thus less fallible) welfare system. In this paper, I argue thatjoined-up thinking can also create a new economy of welfare professional power. First, I show how some versions of 'joined-up' thinking manifest themselves in holistic practices that can 'see everything', 'know everything' and 'do anything', and thus a 'holistic power' to discipline and control every aspect of welfare recipients lives. Since holistic power is seen as infallible, its failure to produce 'active bodies' necessitates the creation of secondary 'joined-up powers' that individualize blame and exclude those to blame from welfare resources. These 'secondary powers' match the social disciplines enforced by one welfare agency (e.g. the responsibility to work enforced by the employment service) with legal rights under another agency (e.g. the right to housing from social landlords), so that breach of the former leads to exclusion from the latter. I conclude that this power strategy is primitive and punitive because it simply excludes welfare recipients. Exclusion is also uneconomic because it pushes welfare recipients into the shade of welfare institutional power. PMID:12945871

  12. Detection and Repair of Ionizing Radiation-Induced DNA Double Strand Breaks: New Developments in Nonhomologous End Joining

    International Nuclear Information System (INIS)

    DNA damage can occur as a result of endogenous metabolic reactions and replication stress or from exogenous sources such as radiation therapy and chemotherapy. DNA double strand breaks are the most cytotoxic form of DNA damage, and defects in their repair can result in genome instability, a hallmark of cancer. The major pathway for the repair of ionizing radiation-induced DSBs in human cells is nonhomologous end joining. Here we review recent advances on the mechanism of nonhomologous end joining, as well as new findings on its component proteins and regulation

  13. Childhood exposure to violence and lifelong health: Clinical intervention science and stress biology research join forces

    Science.gov (United States)

    Moffitt, Terrie E.

    2013-01-01

    Many young people who are mistreated by an adult, victimized by bullies, criminally assaulted, or who witness domestic violence react to this violence exposure by developing behavioral, emotional, or learning problems. What is less well known is that adverse experiences like violence exposure can lead to hidden physical alterations inside a child’s body, alterations which may have adverse effects on life-long health. We discuss why this is important for the field of developmental psychopathology and for society, and we recommend that stress-biology research and intervention science join forces to tackle the problem. We examine the evidence base in relation to stress-sensitive measures for the body (inflammatory reactions, telomere erosion, epigenetic methylation, and gene expression) and brain (mental disorders, neuroimaging, and neuropsychological testing). We also review promising interventions for families, couples, and children that have been designed to reduce the effects of childhood violence exposure. We invite intervention scientists and stress-biology researchers to collaborate in adding stress-biology measures to randomized clinical trials of interventions intended to reduce effects of violence exposure and other traumas on young people. PMID:24342859

  14. Laser-Based Hot-Melt Bonding of Thermosetting GFRP

    Science.gov (United States)

    Amend, P.; Pillach, B.; Frick, T.; Schmidt, M.

    In the future the use of tailored multi-material components will increase because of lightweight constructions. However for an optimal integration of different materials suitable joining techniques are necessary. This paper presents results of joining thermosetting composites to thermoplastics by means of laser-based hot-melt bonding. First the joining process of glass fiber reinforced plastics (GFRP) to thermoplastics is analyzed with regard to appropriate material selection of the thermoplastic joining partner. Then experiments are performed to join two thermosetting GFRP composites using a thermoplastic interlayer. All joined specimens are characterized by tensile shear tests whereby the influences of the used peel ply and the thermoplastic joining partner on the tensile shear strength are analyzed. Finally climate tests are performed to investigate the long-term durability of the joint connections.

  15. Why Children Join and Stay in Sports Clubs: Case Studies in Australian, French and German Swimming Clubs

    Science.gov (United States)

    Light, Richard L.; Harvey, Stephen; Memmert, Daniel

    2013-01-01

    This article builds upon research on youth sport clubs conducted from a socio-cultural perspective by reporting on a study that inquired into the reasons why children aged 9-12 joined swimming clubs in France, Germany and Australia. Comprising three case studies it employed a mixed method approach with results considered within the framework of…

  16. Shear bond strength of different retainer wires and bonding adhesives in consideration of the pretreatment process

    OpenAIRE

    Reicheneder, C. (Claudia); Hofrichter, B. (Bernd); Faltermeier, A. (Andreas); P. Proff; Lippold, C. (Carsten); Kirschneck, C.J. (Christian)

    2015-01-01

    Introduction: We aimed to compare the shear bond strength (SBS) of three different retainer wires and three different bonding adhesives in consideration of the pretreatment process of enamel surface sandblasting. Methods: 400 extracted bovine incisors were divided into 10 groups of 20 paired specimens each. 10 specimens of each group were pretreated by enamel sandblasting. The retainer wires Bond-A-Braid™, GAC-Wildcat®-Twistflex and everStick®ORTHO were bonded to the teeth with the adhesives ...

  17. HYDROGEN BONDING IN POLYMERIC ADSORBENTS BASED ADSORPTION AND SEPARATION

    Institute of Scientific and Technical Information of China (English)

    XUMancai; SHIZuoqing; 等

    2000-01-01

    After a concise introduction of hydrogen bonding effects in solute-solute and solute-solvent bonding,the design of polymeric adsorbents based on hydrogen bonding ,selectivity in adsorption through hydrogen bonding,and characterization of hydrogen bonding in adsorption and separation were reviewed with 28 references.

  18. Analytical and experimental evaluation of joining ceramic oxides to ceramic oxides and ceramic oxides to metal for advanced heat engine applications. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, J.; Majumdar, B.; Rosenfield, A.R.; Swartz, S.L.; Cawley, J.; Park, E.; Hauser, D.; Hopper, A.T. [Battelle Columbus Labs., OH (United States)

    1992-04-01

    The problem of designing reliable, high strength zirconia-to-zirconia and zirconia-to-nodular cast iron joints is addressed by developing a general joint design and assessment methodology. A joint`s load carrying capability is predicted in terms of its material strength and fracture toughness characteristics. The effects of joint constituent properties and joining process variables are included. The methodology is verified in a two step process by applying it first to notched bend bars and then to a notched disk specimen loaded in compression. Key technical accomplishments in the program include the development of a joint design and assessment methodology which predicts failure based on a combination of strength and toughness, the development of a new method of hot forging magnesia partially stabilized zirconia to itself, and the development of a bimaterial disk-shaped specimen notched along the diametral bond line and compressively loaded to generate both shear and tensile loadings on the bond line. Mechanical and thermal characterization of joints, adherents, and interlayer materials were performed to provide data for input to the design methodology. Results from over 150 room temperature tests and 30 high temperature tests are reported. Extensive comparisons of experimental results are made with model predictions of failure load. The joint design and assessment model, as applied to the materials and test specimens of this program, has been programmed for a PC and is available to interested researchers.

  19. Analytical and experimental evaluation of joining ceramic oxides to ceramic oxides and ceramic oxides to metal for advanced heat engine applications

    Energy Technology Data Exchange (ETDEWEB)

    Ahmad, J.; Majumdar, B.; Rosenfield, A.R.; Swartz, S.L.; Cawley, J.; Park, E.; Hauser, D.; Hopper, A.T. (Battelle Columbus Labs., OH (United States))

    1992-04-01

    The problem of designing reliable, high strength zirconia-to-zirconia and zirconia-to-nodular cast iron joints is addressed by developing a general joint design and assessment methodology. A joint's load carrying capability is predicted in terms of its material strength and fracture toughness characteristics. The effects of joint constituent properties and joining process variables are included. The methodology is verified in a two step process by applying it first to notched bend bars and then to a notched disk specimen loaded in compression. Key technical accomplishments in the program include the development of a joint design and assessment methodology which predicts failure based on a combination of strength and toughness, the development of a new method of hot forging magnesia partially stabilized zirconia to itself, and the development of a bimaterial disk-shaped specimen notched along the diametral bond line and compressively loaded to generate both shear and tensile loadings on the bond line. Mechanical and thermal characterization of joints, adherents, and interlayer materials were performed to provide data for input to the design methodology. Results from over 150 room temperature tests and 30 high temperature tests are reported. Extensive comparisons of experimental results are made with model predictions of failure load. The joint design and assessment model, as applied to the materials and test specimens of this program, has been programmed for a PC and is available to interested researchers.

  20. Finite element modelling of hybrid (spot welded/bonded) joints under service conditions

    OpenAIRE

    Dang, Weidong

    2015-01-01

    Spot welding and adhesive bonding are widely used in joining of sheet metals, such as assembling of car body-in-white. Recently, spot weld and adhesive are combined to make weld bonded joint, which is employed to join Advanced High Strength Steel to improve the stiffness and crashworthiness of car body. In industry, the assessment of designing prior to prototype requires reliable constitutive models in terms of the prediction of the mechanical behaviors. The FE model of weld bonded joint is a...

  1. Mechatronic modeling and simulation using bond graphs

    CERN Document Server

    Das, Shuvra

    2009-01-01

    Bond graphs are especially well-suited for mechatronic systems, as engineering system modeling is best handled using a multidisciplinary approach. Bond graphing permits one to see the separate components of an engineering system as a unified whole, and allows these components to be categorized under a few generalized elements, even when they come from different disciplines. In addition to those advantages, the bond graph offers a visual representation of a system from which derivation of the governing equations is algorithmic. This makes the design process accessible to beginning readers, prov

  2. Can Taxes and Bonds Finance Government Spending?

    OpenAIRE

    Stephanie Bell

    1998-01-01

    This paper investigates the commonly held belief that government spending is normally financed through a combination of taxes and bond sales. The argument is a technical one and requires a detailed analysis of reserve accounting at the central bank. After carefully considering the complexities of reserve accounting, it is argued that the proceeds from taxation and bond sales are technically incapable of financing government spending and that modern governments actually finance all of their sp...

  3. Credit unions and the common bond

    OpenAIRE

    William R. Emmons; Frank A. Schmid

    1998-01-01

    A distinguishing feature of credit unions is the legal requirement that members share a common bond. This organizing principle recently became the focus of national attention when the Supreme Court and the U.S. Congress took opposite sides in a controversy regarding the number of common bonds (fields of membership) that could coexist within a single credit union. In this article, Emmons and Schmid develop and simulate a model of credit-union formation and consolidation to examine the effects ...

  4. Bibliography of the technical literature of the Materials Joining Group, Metals and Ceramics Division, 1951 through June 1987

    International Nuclear Information System (INIS)

    This document contains a listing of the written scientific information originating in the Materials Joining Group (formerly the Welding and Brazing Group), Metals and Ceramics Division, Oak Ridge National Laboratory during 1951 through June 1987. It is a registry of about 400 documents as nearly as possible in the order in which they were issued

  5. Bibliography of the technical literature of the Materials Joining Group, Metals and Ceramics Division, 1951 through June 1987

    Energy Technology Data Exchange (ETDEWEB)

    David, S.A.; Goodwin, G.M.; Gardner, K. (comps.)

    1987-08-01

    This document contains a listing of the written scientific information originating in the Materials Joining Group (formerly the Welding and Brazing Group), Metals and Ceramics Division, Oak Ridge National Laboratory during 1951 through June 1987. It is a registry of about 400 documents as nearly as possible in the order in which they were issued.

  6. Joined-up Planetary Information, in the Cloud and on Devices.

    Science.gov (United States)

    Smith, M. J.; Emmott, S.; Purves, D. W.; Joppa, L. N.; Lyutsarev, V.

    2014-12-01

    In scientific research and development, emphasis is placed on research over development. A significant cost is that the two-way interaction between scientific insights and societal needs does not function effectively to lead to impacts in the wider world. We simply must embrace new software and hardware approaches if we are to provide timely predictive information to address global problems, support businesses and inform governments and citizens. The Microsoft Research Computational Science Lab has been pioneering research into software and methodologies to provide useful and usable new environmental information. Our approach has been very joined-up: from accellerating data acquisition from the field with remote sensor technology, targetted data collection and citizen science, to enabling proces based modelling-using multiple heterogeneous data-sets in the cloud and enabling the resulting planetary information to be accessed from any device. This talk will demonstrate some of the specific research and development we are doing to accerate the pace in which important science has impact on the wider world and will emphasise the important insights gained from advancing the research and develoment together.

  7. Decomposing European bond and equity volatility

    DEFF Research Database (Denmark)

    Christiansen, Charlotte

    The paper investigates volatility spillover from US and aggregate European asset markets into European national asset markets. A main contribution is that bond and equity volatilities are analyzed simultaneously. A new model belonging to the "volatilityspillover" family is suggested: The conditio...... (stock) volatilities are mainly influenced by bond (stock) effects. Global, regional, and local volatility effects are all important. The introduction of the euro is associated with a structural break....

  8. Explaining arbitrage of CDS and Bond markets

    OpenAIRE

    Mishyn, Maksym Kostyantynovich

    2014-01-01

    The focus of this paper is the theoretical arbitrage relationship between the Credit Default Swaps and Corporate Bonds. We find that the arbitrage relationship tends to be violated, creating short term opportunities for traders. Results of VECM suggest that the difference in price of credit risk persists over time. This violation is explained by three sets of factors: 1) firm-specific credit risk proxies, 2) bond and CDS liquidity and 3) overall market conditions. Variables gai...

  9. DNA ligases I and III cooperate in alternative non-homologous end-joining in vertebrates.

    Directory of Open Access Journals (Sweden)

    Katja Paul

    Full Text Available Biochemical and genetic studies suggest that vertebrates remove double-strand breaks (DSBs from their genomes predominantly by two non-homologous end joining (NHEJ pathways. While canonical NHEJ depends on the well characterized activities of DNA-dependent protein kinase (DNA-PK and LIG4/XRCC4/XLF complexes, the activities and the mechanisms of the alternative, backup NHEJ are less well characterized. Notably, the contribution of LIG1 to alternative NHEJ remains conjectural and although biochemical, cytogenetic and genetic experiments implicate LIG3, this contribution has not been formally demonstrated. Here, we take advantage of the powerful genetics of the DT40 chicken B-cell system to delineate the roles of LIG1 and LIG3 in alternative NHEJ. Our results expand the functions of LIG1 to alternative NHEJ and demonstrate a remarkable ability for LIG3 to backup DSB repair by NHEJ in addition to its essential function in the mitochondria. Together with results on DNA replication, these observations uncover a remarkable and previously unappreciated functional flexibility and interchangeability between LIG1 and LIG3.

  10. The mining industry and the community: Joining forces for sustainable social development

    International Nuclear Information System (INIS)

    This article joins the continuing policy debate over the social responsibility of corporations, particularly in the mining industry. The author argues that the 'old school mining orthodoxy' - approaching the exploitation of mineral deposits solely from the technical and economic points of view-is long dead. Mining companies must also encompass the social dimension. New policies for the mining industry are discussed in terms of recent worldwide trends and movements, e.g. globalization, economic interdependence and decentralization of governmental authority, and the rise of civil society as a political factor. These trends, together with the United Nations policies in quest of sustainable development and the consensus expressed at international conferences during the last decade, have deepened social awareness and set the stage for enhanced social responsiveness from the private sector. Socially responsible corporate policies include decentralization of decision-making to the field level, reaching out to stake holders and shareholders, supporting governments which provide official development assistance for good governance and building broad partnerships to reduce social exposures. (author)

  11. GDP-linked bonds and sovereign default

    OpenAIRE

    Barr, David; Bush, Oliver; Pienkowski, Alex

    2014-01-01

    Using a calibrated model of endogenous sovereign default, we explore how GDP-linked bonds can raise the maximum sustainable debt level of a government, and substantially reduce the incidence of default. The model explores both the costs (in particular the GDP risk premium) and the benefits of issuing GDP-linked bonds. It concludes that significant welfare gains can be achieved by indexing debt to GDP.

  12. Optimising query execution time in LHCb Bookkeeping System using partition pruning and Partition-Wise joins

    Science.gov (United States)

    Mathe, Zoltan; Charpentier, Philippe

    2014-06-01

    The LHCb experiment produces a huge amount of data which has associated metadata such as run number, data taking condition (detector status when the data was taken), simulation condition, etc. The data are stored in files, replicated on the Computing Grid around the world. The LHCb Bookkeeping System provides methods for retrieving datasets based on their metadata. The metadata is stored in a hybrid database model, which is a mixture of Relational and Hierarchical database models and is based on the Oracle Relational Database Management System (RDBMS). The database access has to be reliable and fast. In order to achieve a high timing performance, the tables are partitioned and the queries are executed in parallel. When we store large amounts of data the partition pruning is essential for database performance, because it reduces the amount of data retrieved from the disk and optimises the resource utilisation. This research presented here is focusing on the extended composite partitioning strategy such as range-hash partition, partition pruning and usage of the Partition-Wise joins. The system has to serve thousands of queries per minute, the performance and capability of the system is measured when the above performance optimization techniques are used.

  13. Optimising query execution time in LHCb Bookkeeping System using partition pruning and Partition-Wise joins

    International Nuclear Information System (INIS)

    The LHCb experiment produces a huge amount of data which has associated metadata such as run number, data taking condition (detector status when the data was taken), simulation condition, etc. The data are stored in files, replicated on the Computing Grid around the world. The LHCb Bookkeeping System provides methods for retrieving datasets based on their metadata. The metadata is stored in a hybrid database model, which is a mixture of Relational and Hierarchical database models and is based on the Oracle Relational Database Management System (RDBMS). The database access has to be reliable and fast. In order to achieve a high timing performance, the tables are partitioned and the queries are executed in parallel. When we store large amounts of data the partition pruning is essential for database performance, because it reduces the amount of data retrieved from the disk and optimises the resource utilisation. This research presented here is focusing on the extended composite partitioning strategy such as range-hash partition, partition pruning and usage of the Partition-Wise joins. The system has to serve thousands of queries per minute, the performance and capability of the system is measured when the above performance optimization techniques are used

  14. Emergence and oscillation of cosmic space by joining M1-branes

    CERN Document Server

    Sepehri, Alireza; Capozziello, Salvatore; Ali, Ahmed Farag; Pradhan, Anirudh

    2016-01-01

    Recently, it has been proposed by Padmanabhan that the difference between the number of degrees of freedom on the boundary surface and the number of degrees of freedom in a bulk region leads to the expansion of the universe. Now, a natural question arises, how this model could explain the oscillation of universe between contraction and expansion branches? We try to address this issue in the framework of BIonic system. In this model, $M0$-branes join to each other and give rise to a pair of $M1$-anti-$M1$-branes. The fields which live on these branes play the roles of massive gravitons that cause the emergence of a wormhole between them and formation of a BIon system. This wormhole dissolves into M1-branes and causes a divergence between the number of degrees of freedom on the boundary surface of $M1$ and the bulk leading to an expansion of $M1$-branes. When $M1$-branes become close to each other, the square energy of their system becomes negative and some tachyonic states emerge. To removes these states, $M1$...

  15. Selecting one of several mating types through gene segment joining and deletion in Tetrahymena thermophila.

    Directory of Open Access Journals (Sweden)

    Marcella D Cervantes

    Full Text Available The unicellular eukaryote Tetrahymena thermophila has seven mating types. Cells can mate only when they recognize cells of a different mating type as non-self. As a ciliate, Tetrahymena separates its germline and soma into two nuclei. During growth the somatic nucleus is responsible for all gene transcription while the germline nucleus remains silent. During mating, a new somatic nucleus is differentiated from a germline nucleus and mating type is decided by a stochastic process. We report here that the somatic mating type locus contains a pair of genes arranged head-to-head. Each gene encodes a mating type-specific segment and a transmembrane domain that is shared by all mating types. Somatic gene knockouts showed both genes are required for efficient non-self recognition and successful mating, as assessed by pair formation and progeny production. The germline mating type locus consists of a tandem array of incomplete gene pairs representing each potential mating type. During mating, a complete new gene pair is assembled at the somatic mating type locus; the incomplete genes of one gene pair are completed by joining to gene segments at each end of germline array. All other germline gene pairs are deleted in the process. These programmed DNA rearrangements make this a fascinating system of mating type determination.

  16. Equity Volatility and Corporate Bond Yields

    OpenAIRE

    Campbell, John; Taksler, Glen

    2002-01-01

    This paper explores the effect of equity volatility on corporate bond yields. Panel data for the late 1990s show that idiosyncratic firm-level volatility can explain as much cross-sectional variation in yields as can credit ratings. This finding, together with the upward trend in idiosyncratic equity volatility documented by Campbell, Lettau, Malkiel, and Xu (2001), helps to explain recent increases in corporate bond yields. The definitive version is available at www.blackwell-synergy.com.

  17. An Ocean Reanalysis System for the Joining Area of Asia and Indian-Pacific Ocean

    Institute of Scientific and Technical Information of China (English)

    YAN Chang-Xiang; ZHU Jiang; XIE Ji-Ping

    2010-01-01

    An ocean reanalysis system for the joining area of Asia and Indian-Pacific Ocean(AIPO)has been developed and is currently delivering reanalysis data sets for study on the air-sea interaction over AIPO and its climate variation over China in the inter-annual time scale.This system consists of a nested ocean model forced by atmospheric reanalysis,an ensemble-based multivariate ocean data assimilation system and various ocean observations.The following report describes the main components of the data assimilation system in detail.The system adopts an ensemble optimal interpolation scheme that uses a seasonal update from a free running model to estimate the background error covariance matrix.In view of the systematic biases in some observation systems,some treatments were performed on the observations before the assimilation.A coarse resolution reanalysis dataset from the system is preliminarily evaluated to demonstrate the performance of the system for the period 1992 to 2006 by comparing this dataset with other observations or reanalysis data.

  18. Correlation of Fe2+ isomer shifts with bond lengths and bond strengths in neso- and sorosilicates

    Institute of Scientific and Technical Information of China (English)

    李哲; E.DeGrave

    1995-01-01

    An evaluation of Mbssbauer isomer shift and quadrupole splitting data of Fe2+ in a number of structurally well characterized neso- and sorosilicates is presented. It is found that the nearly linear correlations exist both between the isomer shift and the bond length and between the isomer shift and the bond strength. These correlations are discussed on the basis of the variation of the s-electron density at the Fe2+ nuclei with the chemical bond characteristics.

  19. Effect of Surface States on Joining Mechanisms and Mechanical Properties of Aluminum Alloy (A5052 and Polyethylene Terephthalate (PET by Dissimilar Friction Spot Welding

    Directory of Open Access Journals (Sweden)

    Farazila Yusof

    2016-04-01

    Full Text Available In this research, polyethylene terephthalate (PET, as a high-density thermoplastic sheet, and Aluminum A5052, as a metal with seven distinct surface roughnesses, were joined by friction spot welding (FSW. The effect of A5052’s various surface states on the welding joining mechanism and mechanical properties were investigated. Friction spot welding was successfully applied for the dissimilar joining of PET thermoplastics and aluminum alloy A5052. During FSW, the PET near the joining interface softened, partially melted and adhered to the A5052 joining surface. The melted PET evaporated to form bubbles near the joining interface and cooled, forming hollows. The bubbles have two opposite effects: its presence at the joining interface prevent PET from contacting with A5052, while bubbles or hollows are crack origins that induce crack paths which degrade the joining strength. On the other hand, the bubbles’ flow pushed the softened PET into irregularities on the roughened surface to form mechanical interlocking, which significantly improved the strength. The tensile-shear failure load for an as-received surface (0.31 μ m Ra specimen was about 0.4–0.8 kN while that for the treated surface (>0.31 μ m Ra specimen was about 4.8–5.2 kN.

  20. Definition and Application of Topological Index Based on Bond Connectivity

    Institute of Scientific and Technical Information of China (English)

    WANG Zhen-dong; YANG Feng; YANG Hai-lang; LUO Ming-dao; QU Song-sheng

    2003-01-01

    Bond connectivity topological index Si based on chemical bonds was defined by using a matrix method.And Si is formed by atomic parameters such as the number of valence electrons,the number of the highest main quantum of atoms and the bonding electrons and bond parameters such as the length of bonds,the electronegativity difference of bonding atoms.The molecular bond connectivity topological index S is composed of Si.The thermodynamic properties of saturated hydrocarbons,unsaturated hydrocarbons,oxygen organic,methane halide and transitional element compounds and the molecular bond connectivity topological index S have an optimal correlative relationship.

  1. Efficient Privacy Preserving Protocols for Similarity Join

    Directory of Open Access Journals (Sweden)

    Bilal Hawashin

    2012-04-01

    Full Text Available During the similarity join process, one or more sources may not allow sharing its data with other sources. In this case, a privacy preserving similarity join is required. We showed in our previous work [4] that using long attributes, such as paper abstracts, movie summaries, product descriptions, and user feedbacks, could improve the similarity join accuracy using supervised learning. However, the existing secure protocols for similarity join methods can not be used to join sources using these long attributes. Moreover, the majority of the existing privacy‐preserving protocols do not consider the semantic similarities during the similarity join process. In this paper, we introduce a secure efficient protocol to semantically join sources when the join attributes are long attributes. We provide two secure protocols for both scenarios when a training set exists and when there is no available training set. Furthermore, we introduced the multi‐label supervised secure protocol and the expandable supervised secure protocol. Results show that our protocols can efficiently join sources using the long attributes by considering the semantic relationships among the long string values. Therefore, it improves the overall secure similarity join performance.

  2. Comparison of scaffold-enhanced albumin and n-butyl-cyanoacrylate adhesives for joining of tissue in a porcine model

    Science.gov (United States)

    McNally-Heintzelman, Karen M.; Riley, Jill N.; Heintzelman, Douglas L.

    2003-06-01

    An ex vivo study was conducted to compare the tensile strength of tissue samples repaired using three different techniques: (i) application of a scaffold-enhanced light-activated albumin protein solder, (ii) application of a scaffold-enhanced n-butyl-cyanoacrylate adhesive, and (iii) repair via conventional suture technique. Biodegradable polymer scaffolds of controlled porosity were fabricated with poly(L-lactic-co-glycolic acid) and salt particles using a solvent-casting and particulate-leaching technique. Group I porous scaffolds were doped with protein solder composed of 50%(w/v) bovine serum albumin solder and 0.5mg/ml indocyanine green dye mixed in deionized water, and activated with an 808-nm diode laser. Group II scaffolds were doped with n-butyl-cyanoacrylate, and required no light-activation. No stay sutures were required for Group I or II experiments. Group III repairs were performed using a single 4-0 suture. Thirteen organs were tested ranging from skin to liver to the small intestine, as well as the coronary, pulmonary, carotid, femoral and splenic arteries. Acute breaking strengths were measured and the data were analyzed by Student"s T-test. Using the protein solder of Group I, repairs formed on the ureter were most successful followed by small intestine, sciatic nerve, spleen, atrium, kidney, muscle, skin and ventricle. The strongest vascular repairs were achieved in the carotid artery and femoral artery. Overall, the tensile strength of Group III repairs performed via suture techniques were equivalent in magnitude to that of Group I repairs, however, a larger variance was observed in the suture repair group. Group II repairs utilizing the cyanoacrylate-doped scaffold all performed extremely well. Bonds formed using the Group II adhesive were approximately 30% stronger than Group I and III organ repairs and approximately 20% stronger than Group I and III vascular repairs. Application of the polymer scaffold assists in tissue alignment and reduces

  3. A review of joining techniques for SiCf/SiC composites for first wall applications

    International Nuclear Information System (INIS)

    Many methods for joining monolithic and composite silicon carbide are available. Three techniques are candidates for use in fusion energy systems: in-situ displacement reactions, pre-ceramic polymer adhesives, and reaction bonding. None of the methods are currently developed enough to satisfy all of the criteria required, i.e., low temperature fabrication, high strength, and radiation stability. 58 refs

  4. Emergence and oscillation of cosmic space by joining M1-branes

    Energy Technology Data Exchange (ETDEWEB)

    Sepehri, Alireza [Shahid Bahonar University, Faculty of Physics, Kerman (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha (RIAAM), Maragha (Iran, Islamic Republic of); Rahaman, Farook [Jadavpur University, Department of Mathematics, Kolkata, West Bengal (India); Capozziello, Salvatore [Universita di Napoli Federico II, Dipartimento di Fisica ' ' E. Pancini' ' , Naples (Italy); Gran Sasso Science Institute (INFN), L' Aquila (Italy); Tomsk State Pedagogical University, Tomsk (Russian Federation); INFN Sezione di Napoli, Naples (Italy); Ali, Ahmed Farag [Benha University, Department of Physics, Faculty of Science, Benha (Egypt); Pradhan, Anirudh [G L A University, Department of Mathematics, Institute of Applied Sciences and Humanities, Mathura, Uttar Pradesh (India)

    2016-05-15

    Recently, it has been proposed by Padmanabhan that the difference between the number of degrees of freedom on the boundary surface and the number of degrees of freedom in a bulk region leads to the expansion of the universe. Now, a natural question arises; how could this model explain the oscillation of the universe between contraction and expansion branches? We try to address this issue in the framework of a BIonic system. In this model, M0-branes join to each other and give rise to a pair of M1-anti-M1-branes. The fields which live on these branes play the roles of massive gravitons that cause the emergence of a wormhole between them and formation of a BIon system. This wormhole dissolves into M1-branes and causes a divergence between the number of degrees of freedom on the boundary surface of M1 and the bulk leading to an expansion of M1-branes. When M1-branes become close to each other, the square energy of their system becomes negative and some tachyonic states emerge. To remove these states, M1-branes become compact, the sign of compacted gravity changes, causing anti-gravity to arise: in this case, branes get away from each other. By articulating M1-BIons, an M3-brane and an anti-M3-brane are created and connected by three wormholes forming an M3-BIon. This new system behaves like the initial system and by closing branes to each other, they become compact and, by getting away from each other, they open. Our universe is located on one of these M3-branes and, by compactifying the M3-brane, it contracts and, by opening it, it expands. (orig.)

  5. Emergence and oscillation of cosmic space by joining M1-branes

    Science.gov (United States)

    Sepehri, Alireza; Rahaman, Farook; Capozziello, Salvatore; Ali, Ahmed Farag; Pradhan, Anirudh

    2016-05-01

    Recently, it has been proposed by Padmanabhan that the difference between the number of degrees of freedom on the boundary surface and the number of degrees of freedom in a bulk region leads to the expansion of the universe. Now, a natural question arises; how could this model explain the oscillation of the universe between contraction and expansion branches? We try to address this issue in the framework of a BIonic system. In this model, M0-branes join to each other and give rise to a pair of M1-anti- M1-branes. The fields which live on these branes play the roles of massive gravitons that cause the emergence of a wormhole between them and formation of a BIon system. This wormhole dissolves into M1-branes and causes a divergence between the number of degrees of freedom on the boundary surface of M1 and the bulk leading to an expansion of M1-branes. When M1-branes become close to each other, the square energy of their system becomes negative and some tachyonic states emerge. To remove these states, M1-branes become compact, the sign of compacted gravity changes, causing anti-gravity to arise: in this case, branes get away from each other. By articulating M1-BIons, an M3-brane and an anti- M3-brane are created and connected by three wormholes forming an M3-BIon. This new system behaves like the initial system and by closing branes to each other, they become compact and, by getting away from each other, they open. Our universe is located on one of these M3-branes and, by compactifying the M3-brane, it contracts and, by opening it, it expands.

  6. Innovative Structural and Joining Concepts for Lightweight Design of Heavy Vehicle Systems

    Energy Technology Data Exchange (ETDEWEB)

    Jacky C. Prucz; Samir N. Shoukry; Gergis W. William

    2005-08-31

    heavy vehicles. The research work planed for the first year of this project (June 1, 2003 through May 30, 2004) focused on a theoretical investigation of weight benefits and structural performance tradeoffs associated with the design, fabrication, and joining of MMC components for heavy-duty vehicles. This early research work conducted at West Virginia University yielded the development of integrated material-structural models that predicted marginal benefits and significant barriers to MMC applications in heavy trailers. The results also indicated that potential applications of MMC materials in heavy vehicles are limited to components identified as critical for either loadings or weight savings. Therefore, the scope of the project was expanded in the following year (June 1, 2004 through May 30, 2005) focused on expanding the lightweight material-structural design concepts for heavy vehicles from the component to the system level. Thus, the following objectives were set: (1) Devise and evaluate lightweight structural configurations for heavy vehicles. (2) Study the feasibility of using Metal Matrix Composites (MMC) for critical structural components and joints in heavy vehicles. (3) Develop analysis tools, methods, and validated test data for comparative assessments of innovative design and joining concepts. (4) Develop analytical models and software for durability predictions of typical heavy vehicle components made of particulate MMC or fiber-reinforced composites. This report summarizes the results of the research work conducted during the past two years in this projects.

  7. Reinforced direct bonding of optical materials by femtosecond laser welding.

    Science.gov (United States)

    Hélie, David; Bégin, Michael; Lacroix, Fabrice; Vallée, Réal

    2012-04-20

    A process for reinforcing a direct bond between optical materials using femtosecond laser welding is presented. As a side benefit, the optical transmission properties of the joined components are shown not to be altered by the joining process. The joints exhibits higher shear breakage loads, yielding a maximum measured joint strength of 5.25 MPa for an applied load of 75 kg in fused silica. The laser sealing of direct bonds between dissimilar materials improves their resistance to thermal shocks. Direct bonds sealed by a circular weld seam can withstand thermal shocks at temperatures at least twice as great as nonreinforced direct bonds. The combination of ultrashort laser welding and direct bonding provides an innovative joining method that benefits from the advantages of both contributing physical processes. PMID:22534922

  8. LAMMPS Framework for Dynamic Bonding and an Application Modeling DNA

    DEFF Research Database (Denmark)

    Svaneborg, Carsten

    2012-01-01

    and bond types. When breaking bonds, all angular and dihedral interactions involving broken bonds are removed. The framework allows chemical reactions to be modeled, and use it to simulate a simplistic, coarse-grained DNA model. The resulting DNA dynamics illustrates the power of the present framework.......We have extended the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) to support directional bonds and dynamic bonding. The framework supports stochastic formation of new bonds, breakage of existing bonds, and conversion between bond types. Bond formation can be controlled to...... limit the maximal functionality of a bead with respect to various bond types. Concomitant with the bond dynamics, angular and dihedral interactions are dynamically introduced between newly connected triplets and quartets of beads, where the interaction type is determined from the local pattern of bead...

  9. Electronic structure and bonding in crystalline peroxides

    Science.gov (United States)

    Königstein, Markus; Sokol, Alexei A.; Catlow, C. Richard A.

    1999-08-01

    Hartree-Fock and density-functional PW91 theories as realized in the CRYSTAL95 code have been applied to investigate the structural and electronic properties of Ba, Sr, and Ca peroxide materials with the calcium carbide crystal structure, results for which are compared with those for the corresponding oxides. Special attention is paid to the stabilization of the peroxide molecular ion O2-2 in the ionic environment provided by the lattice, and to chemical bonding effects. In order to describe the covalent bonding within the O2-2 ion and the polarization of the O- ion in the crystal electrostatic field, it is essential to include an account of the effects of electron correlation. The PW91 density functional has allowed us to reproduce the crystallographic parameters within a 3% error. The chemical bonding within the peroxide molecular ion has a complex nature with a balance between the weak covalent bond of σz type and the strong electrostatic repulsion of the closed-shell electron groups occupying O 2s and O 2px and 2py states. Compression of the peroxide ion in the ionic crystals gives rise to an excessive overlap of the O 2s closed shells of the two O- ions of a peroxide molecular ion O2-2, which in turn determines the antibonding character of the interaction and chemical bonding in the O2-2 molecular ion.

  10. Joining of Tungsten Armor Using Functional Gradients

    International Nuclear Information System (INIS)

    The joining of low thermal expansion armor materials such as tungsten to high thermal expansion heat sink materials has been a major problem in plasma facing component (PFC) development. Conventional planar bonding techniques have been unable to withstand the high thermal induced stresses resulting from fabrication and high heat flux testing. During this investigation, innovative functional gradient joints produced using vacuum plasma spray forming techniques have been developed for joining tungsten armor to copper alloy heat sinks. A model was developed to select the optimum gradient architecture. Based on the modeling effort, a 2mm copper rich gradient was selected. Vacuum plasma pray parameters and procedures were then developed to produce the functional gradient joint. Using these techniques, dual cooling channel, medium scale mockups (32mm wide x 400mm length) were produced with vacuum plasma spray formed tungsten armor. The thickness of the tungsten armor was up to 5mm thick. No evidence of debonding at the interface between the heat sink and the vacuum plasma sprayed material was observed.

  11. Ancient and recent adaptive evolution of primate non-homologous end joining genes.

    Directory of Open Access Journals (Sweden)

    Ann Demogines

    2010-10-01

    Full Text Available In human cells, DNA double-strand breaks are repaired primarily by the non-homologous end joining (NHEJ pathway. Given their critical nature, we expected NHEJ proteins to be evolutionarily conserved, with relatively little sequence change over time. Here, we report that while critical domains of these proteins are conserved as expected, the sequence of NHEJ proteins has also been shaped by recurrent positive selection, leading to rapid sequence evolution in other protein domains. In order to characterize the molecular evolution of the human NHEJ pathway, we generated large simian primate sequence datasets for NHEJ genes. Codon-based models of gene evolution yielded statistical support for the recurrent positive selection of five NHEJ genes during primate evolution: XRCC4, NBS1, Artemis, POLλ, and CtIP. Analysis of human polymorphism data using the composite of multiple signals (CMS test revealed that XRCC4 has also been subjected to positive selection in modern humans. Crystal structures are available for XRCC4, Nbs1, and Polλ; and residues under positive selection fall exclusively on the surfaces of these proteins. Despite the positive selection of such residues, biochemical experiments with variants of one positively selected site in Nbs1 confirm that functions necessary for DNA repair and checkpoint signaling have been conserved. However, many viruses interact with the proteins of the NHEJ pathway as part of their infectious lifecycle. We propose that an ongoing evolutionary arms race between viruses and NHEJ genes may be driving the surprisingly rapid evolution of these critical genes.

  12. Application of Filters to Multiway Joins in MapReduce

    Directory of Open Access Journals (Sweden)

    Taewhi Lee

    2014-01-01

    be replicated, so multiple sets of filters need to be created, which depend on the number of join attributes. The experimental results showed that our approach outperformed a cascade of two-way joins and basic multiway joins in cases where small portions of input datasets were joined.

  13. 53BP1 regulates DNA resection and the choice between classical and alternative end joining during class switch recombination.

    Science.gov (United States)

    Bothmer, Anne; Robbiani, Davide F; Feldhahn, Niklas; Gazumyan, Anna; Nussenzweig, Andre; Nussenzweig, Michel C

    2010-04-12

    Class switch recombination (CSR) diversifies antibodies by joining highly repetitive DNA elements, which are separated by 60-200 kbp. CSR is initiated by activation-induced cytidine deaminase, an enzyme that produces multiple DNA double-strand breaks (DSBs) in switch regions. Switch regions are joined by a mechanism that requires an intact DNA damage response and classical or alternative nonhomologous end joining (A-NHEJ). Among the DNA damage response factors, 53BP1 has the most profound effect on CSR. We explore the role of 53BP1 in intrachromosomal DNA repair using I-SceI to introduce paired DSBs in the IgH locus. We find that the absence of 53BP1 results in an ataxia telangiectasia mutated-dependent increase in DNA end resection and that resected DNA is preferentially repaired by microhomology-mediated A-NHEJ. We propose that 53BP1 favors long-range CSR in part by protecting DNA ends against resection, which prevents A-NHEJ-dependent short-range rejoining of intra-switch region DSBs.

  14. Bonding theory for metals and alloys

    CERN Document Server

    Wang, Frederick E

    2005-01-01

    Bonding Theory for Metals and Alloys exhorts the potential existence of covalent bonding in metals and alloys. Through the recognition of the covalent bond in coexistence with the 'free' electron band, the book describes and demonstrates how the many experimental observations on metals and alloys can all be reconciled. Subsequently, it shows how the individual view of metals and alloys by physicists, chemists and metallurgists can be unified. The physical phenomena of metals and alloys covered in this book are: Miscibility Gap between two liquid metals; Phase Equilibrium Diagrams; Phenomenon of Melting. Superconductivity; Nitinol; A Metal-Alloy with Memory; Mechanical Properties; Liquid Metal Embrittlement; Superplasticity; Corrosion; The author introduces a new theory based on 'Covalon' conduction, which forms the basis for a new approach to the theory of superconductivity. This new approach not only explains the many observations made on the phenomenon of superconductivity but also makes predictions that ha...

  15. Bond strength, bond stress and spallation mechanisms of thermal barrier coatings

    Energy Technology Data Exchange (ETDEWEB)

    Gell, M.; Krishnakumar, V.; McCarron, K.; Barber, B.; Sohn, Y.-H. [Connecticut Univ., Storrs, CT (United States). Dept. of Metall. and Mater. Eng.; Eric, J. [Connecticut Univ., Storrs, CT (United States). Dept. of Mechanical Engineering; Tolpygo, V.K.

    1999-11-01

    Five production thermal barrier coatings were thermally cycled between room temperature and 1121 C (2050 F) to determine relative spallation life. Bond strength measurements were made using a modified ASTM direct pull-test. Bond stress measurements were made in the thermally grown oxide using a laser photoluminescence technique. Bond strength and bond stress measurements were conducted on two electron beam physical vapor deposition coatings as a function of thermal cycling. Each coating showed characteristic values of as-coated strength and stress and changes in strength and stress with thermal cycling. These variations in strength and stress with thermal cycling are related to oxidation and micro-debonding effects. (orig.)

  16. Bond strength, bond stress and spallation mechanisms of thermal barrier coatings

    International Nuclear Information System (INIS)

    Five production thermal barrier coatings were thermally cycled between room temperature and 1121 C (2050 F) to determine relative spallation life. Bond strength measurements were made using a modified ASTM direct pull-test. Bond stress measurements were made in the thermally grown oxide using a laser photoluminescence technique. Bond strength and bond stress measurements were conducted on two electron beam physical vapor deposition coatings as a function of thermal cycling. Each coating showed characteristic values of as-coated strength and stress and changes in strength and stress with thermal cycling. These variations in strength and stress with thermal cycling are related to oxidation and micro-debonding effects. (orig.)

  17. Generalized join-hemimorphisms on Boolean algebras

    OpenAIRE

    Sergio Celani

    2003-01-01

    We introduce the notions of generalized join-hemimorphism and generalized Boolean relation as an extension of the notions of join-hemimorphism and Boolean relation, respectively. We prove a duality between these two notions. We will also define a generalization of the notion of Boolean algebra with operators by considering a finite family of Boolean algebras endowed with a generalized join-hemimorphism. Finally, we define suitable notions of subalgebra, congruences, Boole...

  18. Comparative evaluation of the bonding efficacy of sixth and seventh generation bonding agents: An In-Vitro study

    OpenAIRE

    Nair, Manuja; Paul, Joseph; Kumar, Satheesh; Chakravarthy, Yadav; Krishna, Vel; Shivaprasad

    2014-01-01

    Aims: To compare the shear bond strength of sixth generation and seventh generation bonding agents to dentin. Materials and Methods: Eighty human maxillary premolars were reduced to expose flat surface of dentin and divided into four equal groups, which were bonded using following bonding agents: Sixth generation bonding agents, Adper SE Plus and Xeno III and Seventh generation bonding agents, Adper Easy One and Xeno V. Composite cylinders were then built using a plastic mould on these prepar...

  19. Comparative evaluation of the bonding efficacy of sixth and seventh generation bonding agents: An In-Vitro study

    OpenAIRE

    Manuja Nair; Joseph Paul; Satheesh Kumar; Yadav Chakravarthy; Vel Krishna; Shivaprasad

    2014-01-01

    Aims: To compare the shear bond strength of sixth generation and seventh generation bonding agents to dentin. Materials and Methods: Eighty human maxillary premolars were reduced to expose flat surface of dentin and divided into four equal groups, which were bonded using following bonding agents: Sixth generation bonding agents, Adper SE Plus and Xeno III and Seventh generation bonding agents, Adper Easy One and Xeno V. Composite cylinders were then built using a plastic mould on these pr...

  20. Stock vs. Bond Yields, and Demographic Fluctuations

    DEFF Research Database (Denmark)

    Gozluklu, Arie; Morin, Annaïg

    This paper analyzes the strong comovement between real stock and nominal bond yields at generational (low) frequencies. Life-cycle patterns in savings behavior in an overlapping generations model with cash-in-advance constraints explain this persistent comovement between financial yields. We argue...... that the slow-evolving time-series covariation due to changing population age structure accounts for the equilibrium relation between stock and bond markets. As a result, by exploiting the demographic information into distant future, the forecasting performance of evaluation models improves. Finally, using...... a cross-country panel, we document the cross-sectional variation of the demographic effect and explain the cross-country differences in comovement between stock and bond markets....

  1. Deformation and Failure of Polymer Bonded Explosives

    Institute of Scientific and Technical Information of China (English)

    陈鹏万; 黄风雷; 丁雁生

    2004-01-01

    The deformation and failure of pressed polymer bonded explosives under different types of loads including tension, compression and low velocity impact are presented. Brazilian test is used to study the tensile properties. The microstructure of polymer bonded explosives and its evolution are studied by use of scanning electronic microscopy and polarized light microscopy. Polishing techniques have been developed to prepare samples for microscopic examination. The failure mechanisms of polymer bonded explosives under different loads are analyzed. The results show that interfacial debonding is the predominant failure mode in quasi-static tension, while extensive crystal fractures are induced in compression. With the increase of strain rate, more crystal fractures occur. Low velocity impact also induces extensive crystal fractures.

  2. Symmetry in bonding and spectra an introduction

    CERN Document Server

    Douglas, Bodie E

    1985-01-01

    Many courses dealing with the material in this text are called ""Applications of Group Theory."" Emphasizing the central role and primary importance of symmetry in the applications, Symmetry in Bonding and Spectra enables students to handle applications, particularly applications to chemical bonding and spectroscopy. It contains the essential background in vectors and matrices for the applications, along with concise reviews of simple molecular orbital theory, ligand field theory, and treatments of molecular shapes, as well as some quantum mechanics. Solved examples in the text illustra

  3. Comparison of Bond Character in Hydrocarbons and Fullerenes

    OpenAIRE

    Snoke, D. W.; Cardona, M.; Sanguinetti, S.; Benedek, G

    1996-01-01

    We present a comparison of the bond polarizabilities for carbon-carbon bonds in hydrocarbons and fullerenes, using two different models for the fullerene Raman spectrum and the results of Raman measurements on ethane and ethylene. We find that the polarizabilities for single bonds in fullerenes and hydrocarbons compare well, while the double bonds in fullerenes have greater polarizability than in ethylene.

  4. Ancient and Recent Adaptive Evolution of Primate Non-Homologous End Joining Genes

    OpenAIRE

    Ann Demogines; Alysia M East; Ji-Hoon Lee; Grossman, Sharon R.; Sabeti, Pardis C.; Paull, Tanya T.; Sawyer, Sara L.

    2010-01-01

    In human cells, DNA double-strand breaks are repaired primarily by the non-homologous end joining (NHEJ) pathway. Given their critical nature, we expected NHEJ proteins to be evolutionarily conserved, with relatively little sequence change over time. Here, we report that while critical domains of these proteins are conserved as expected, the sequence of NHEJ proteins has also been shaped by recurrent positive selection, leading to rapid sequence evolution in other protein domains. In order to...

  5. INTEREST RATES AND CURRENCIES EFFECTS ON ISLAMIC AND CONVENTIONAL BONDS

    Directory of Open Access Journals (Sweden)

    Ghazali Syamni

    2011-09-01

    Full Text Available Bond markets have not been well developed in emerging countries. Realizing its important role, especially after the 1997 crises and the islamic economics development, emerging countries have started to develop such markets. This research examines the effect of interest rates and currencies on Islamic and conventional bonds in Bursa Malaysia. The analysis on Islamic bonds shows that interest rates and currencies do not influence Islamic bonds, which supports the prohibition of interest in Islam. The analysis on conventional bonds finds evidence that both interest rates and currencies affect conventional bond. It also finds evidence of a negative association between interest rates and a conventional bond. Keywords: Interest rate, currency, conventional bond, Islamic bond JEL classification numbers: G11, G12, G15

  6. Continuing Relationships with the Deceased: Disentangling Bonds and Grief

    Science.gov (United States)

    Schut, Henk A. W.; Stroebe, Margaret S.; Boelen, Paul A.; Zijerveld, Annemieke M.

    2006-01-01

    Some studies of the relationship between continuing bonds and grief intensity have claimed that continuing bonds lead to poor adaptation to bereavement. However, operationalizations of continuing bonds and grief intensity appear to overlap conceptually. Thus, it is still unclear what character the connection between continuing bonds and grief…

  7. Bibliography of the technical literature of the Materials Joining Group, Metals and Ceramics Division, 1951--June 1989

    Energy Technology Data Exchange (ETDEWEB)

    David, S.A.; Goodwin, G.M.; Gardner, K. (comps.)

    1989-10-01

    This document contains a listing of the written scientific information originating in the Materials Joining (formerly the Welding and Brazing Group), Metals and Ceramics Division, Oak Ridge National Laboratory during 1951 through June 1989. This registry of documents is as much as possible, in the order of issue date. A complete cross-referenced listing of the technical literature of the Metals and Ceramics Division is also available.

  8. Diffusion Bonding Behavior and Characterization of Joints Made Between 316L Stainless Steel Alloy and AZ31 Magnesium Alloy

    Science.gov (United States)

    Elthalabawy, Waled Mohamed

    The 316L austenitic stainless steel and AZ31 magnesium alloy have physical and mechanical properties which makes these alloys suitable in a number of high technology based industries such as the aerospace and automotive sectors. However, for these alloys to be used in engineering applications, components must be fabricated and joined successfully. The differences in the physical and metallurgical properties between these two alloys prevents the use of conventional fusion welding processes commonly employed in aerospace and transport industry. Therefore, alternative techniques need to be developed and diffusion bonding technology is a process that has considerable potential to join these two dissimilar alloys. In this research work both solid-state and transient liquid phase (TLP) bonding processes were applied. The solid-state bonding of 316L steel to AZ31 magnesium alloy was possible at a bonding temperature of 550°C for 120 minutes using a pressure of 1.3 MPa. The interface characterization of the joint showed a thin intermetallic zone rich in Fe-Al was responsible for providing a metallurgical bond. However, low joint shear strengths were recorded and this was attributed to the poor surface to surface contact. The macro-deformation of the AZ31 alloy prevented the use of higher bonding pressures and longer bonding times. In order to overcome these problems, the TLP bonding process was implemented using pure Cu and Ni foils as interlayers which produced a eutectic phase at the bonding temperature. This research identified the bonding mechanism through microstructural and differential scanning calorimetry investigations. The microstructural characterization of the TLP joints identified intermetallics which became concentrated along the 316L steel/AZ31 bond interface due to the "pushing effect" of the solid/liquid interface during isothermal solidification stage of bonding. The size and concentration of the intermetallics had a noticeable effect on the final joint

  9. Expected Business Conditions and Bond Risk Premia

    DEFF Research Database (Denmark)

    Eriksen, Jonas Nygaard

    2015-01-01

    This paper studies the predictability of bond risk premia by means of expectations to future business conditions using survey forecasts from the Survey of Professional Forecasters. We show that expected business conditions consistently affect excess bond returns and that the inclusion of expected...... business conditions in standard predictive regressions improve forecast performance relative to models using information derived from the current term structure or macroeconomic variables. The results are confirmed in a real-time out-of-sample exercise, where the models predictive accuracy are evaluated...

  10. Expected Business Conditions and Bond Risk Premia

    DEFF Research Database (Denmark)

    Eriksen, Jonas Nygaard

    business conditions in standard predictive regressions improve forecast performance relative to models using information derived from the current term structure or macroeconomic variables. The results are confirmed in a real-time out-of-sample exercise, where the predictive accuracy of the models......This paper studies the predictability of bond risk premia by means of expectations to future business conditions using survey forecasts from the Survey of Professional Forecasters. We show that expected business conditions consistently affect excess bond returns and that the inclusion of expected...

  11. [Morita Therapy to Treat Depression: When and How to Encourage Patients to Join Activities].

    Science.gov (United States)

    Nakamura, Kei

    2015-01-01

    The author discusses how Morita therapy is used to treat depression, illustrated with a clinical case, and makes comparisons between Morita therapy and behavioral activation (BA). The author further examines the issue of when and how to encourage patients to join activities in clinical practice in Japan. Both Morita therapy and BA share at least a common view that it is effective to activate patients' constructive behavior at a certain point in depression treatment. However, BA therapists, compared to Morita therapists, seem to pay less attention to the necessity of resting and the appropriate timing for introducing behavioral activation. There may be some contextual differences between depressive patients in Japan and those in North America. In the case of Japanese patients, exhaustion from overwork is often considered a factor triggering the development of depression. At the same time, the Morita-based pathogenic model of depression seems different from BA's model of the same disorder. BA's approach to understanding depression may be considered a psychological (behavioristic) model. In this model, the cause of depression lies in: (a) a lack of positive reinforcement, and (b) negative reinforcement resulting from avoidance of the experience of discomfort. Therefore, the basic strategy of BA is to release depressive patients from an avoidant lifestyle, which serves as a basis for negative reinforcement, and to redirect the patients toward activities which offer the experience of positive reinforcement BA is primarily practiced by clinical psychologists in the U. S. while psychiatrists prescribe medication as a medical service. On the other hand, the clinical practice of treating depression in Japan is based primarily on medical models of depression. This is also true of Morita therapy, but in a broad sense. While those who follow medical models in a narrow sense try to identify the cause of illness and then remove it, Morita therapists pay more attention to the

  12. [Morita Therapy to Treat Depression: When and How to Encourage Patients to Join Activities].

    Science.gov (United States)

    Nakamura, Kei

    2015-01-01

    The author discusses how Morita therapy is used to treat depression, illustrated with a clinical case, and makes comparisons between Morita therapy and behavioral activation (BA). The author further examines the issue of when and how to encourage patients to join activities in clinical practice in Japan. Both Morita therapy and BA share at least a common view that it is effective to activate patients' constructive behavior at a certain point in depression treatment. However, BA therapists, compared to Morita therapists, seem to pay less attention to the necessity of resting and the appropriate timing for introducing behavioral activation. There may be some contextual differences between depressive patients in Japan and those in North America. In the case of Japanese patients, exhaustion from overwork is often considered a factor triggering the development of depression. At the same time, the Morita-based pathogenic model of depression seems different from BA's model of the same disorder. BA's approach to understanding depression may be considered a psychological (behavioristic) model. In this model, the cause of depression lies in: (a) a lack of positive reinforcement, and (b) negative reinforcement resulting from avoidance of the experience of discomfort. Therefore, the basic strategy of BA is to release depressive patients from an avoidant lifestyle, which serves as a basis for negative reinforcement, and to redirect the patients toward activities which offer the experience of positive reinforcement BA is primarily practiced by clinical psychologists in the U. S. while psychiatrists prescribe medication as a medical service. On the other hand, the clinical practice of treating depression in Japan is based primarily on medical models of depression. This is also true of Morita therapy, but in a broad sense. While those who follow medical models in a narrow sense try to identify the cause of illness and then remove it, Morita therapists pay more attention to the

  13. Dissimilar Joining of ODS and F/M Steel Tube by Friction Stir Welding

    International Nuclear Information System (INIS)

    martensite, and the oxide particles are uniformly distributed as the mechanical alloying (MA) process. FSW was successfully applied for joining of tube and end-plug

  14. Dissimilar Joining of ODS and F/M Steel Tube by Friction Stir Welding

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Suk Hoon; Noh, Sanghoon; Kim, Jun Hwan; Kim, Tae Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    martensite, and the oxide particles are uniformly distributed as the mechanical alloying (MA) process. FSW was successfully applied for joining of tube and end-plug.

  15. FE modeling of Cu wire bond process and reliability

    NARCIS (Netherlands)

    Yuan, C.A.; Weltevreden, E.R.; Akker, P. van den; Kregting, R.; Vreugd, J. de; Zhang, G.Q.

    2011-01-01

    Copper based wire bonding technology is widely accepted by electronic packaging industry due to the world-wide cost reduction actions (compared to gold wire bond). However, the mechanical characterization of copper wire differs from the gold wire; hence the new wire bond process setting and new bond

  16. Hybrid layer difference between sixth and seventh generation bonding agent

    Directory of Open Access Journals (Sweden)

    Grace Syavira Suryabrata

    2006-03-01

    Full Text Available Since etching is completed at the same stage as priming and bonding, when applying the sixth and seventh generation bonding, the exposed smear layers are constantly surrounded by primer and bonding and cannot collapse. The smear layer and the depth of penetration of resin bonding in dentinal tubules are completely integrated into hybrid layer. The purpose of this laboratory research was to study the penetration depth of two self etching adhesive. Fourteen samples of human extracted teeth were divided into two groups. Each groups consisted of seven samples, each of them was treated with sixth generation bonding agent and the other was treated with seventh generation bonding agent. The results disclosed that the penetration into dentinal tubules of seventh generation bonding agent was deeper than sixth generation bonding agent. Conclusion: bond strength will improve due to the increasing of penetration depth of resin bonding in dentinal tubules.

  17. Fork-join and data-driven execution models on multi-core architectures: Case study of the FMM

    KAUST Repository

    Amer, Abdelhalim

    2013-01-01

    Extracting maximum performance of multi-core architectures is a difficult task primarily due to bandwidth limitations of the memory subsystem and its complex hierarchy. In this work, we study the implications of fork-join and data-driven execution models on this type of architecture at the level of task parallelism. For this purpose, we use a highly optimized fork-join based implementation of the FMM and extend it to a data-driven implementation using a distributed task scheduling approach. This study exposes some limitations of the conventional fork-join implementation in terms of synchronization overheads. We find that these are not negligible and their elimination by the data-driven method, with a careful data locality strategy, was beneficial. Experimental evaluation of both methods on state-of-the-art multi-socket multi-core architectures showed up to 22% speed-ups of the data-driven approach compared to the original method. We demonstrate that a data-driven execution of FMM not only improves performance by avoiding global synchronization overheads but also reduces the memory-bandwidth pressure caused by memory-intensive computations. © 2013 Springer-Verlag.

  18. Bond-length distributions for ions bonded to oxygen: alkali and alkaline-earth metals.

    Science.gov (United States)

    Gagné, Olivier Charles; Hawthorne, Frank Christopher

    2016-08-01

    Bond-length distributions have been examined for 55 configurations of alkali-metal ions and 29 configurations of alkaline-earth-metal ions bonded to oxygen, for 4859 coordination polyhedra and 38 594 bond distances (alkali metals), and for 3038 coordination polyhedra and 24 487 bond distances (alkaline-earth metals). Bond lengths generally show a positively skewed Gaussian distribution that originates from the variation in Born repulsion and Coulomb attraction as a function of interatomic distance. The skewness and kurtosis of these distributions generally decrease with increasing coordination number of the central cation, a result of decreasing Born repulsion with increasing coordination number. We confirm the following minimum coordination numbers: ([3])Li(+), ([3])Na(+), ([4])K(+), ([4])Rb(+), ([6])Cs(+), ([3])Be(2+), ([4])Mg(2+), ([6])Ca(2+), ([6])Sr(2+) and ([6])Ba(2+), but note that some reported examples are the result of extensive dynamic and/or positional short-range disorder and are not ordered arrangements. Some distributions of bond lengths are distinctly multi-modal. This is commonly due to the occurrence of large numbers of structure refinements of a particular structure type in which a particular cation is always present, leading to an over-representation of a specific range of bond lengths. Outliers in the distributions of mean bond lengths are often associated with anomalous values of atomic displacement of the constituent cations and/or anions. For a sample of ([6])Na(+), the ratio Ueq(Na)/Ueq(bonded anions) is partially correlated with 〈([6])Na(+)-O(2-)〉 (R(2) = 0.57), suggesting that the mean bond length is correlated with vibrational/displacement characteristics of the constituent ions for a fixed coordination number. Mean bond lengths also show a weak correlation with bond-length distortion from the mean value in general, although some coordination numbers show the widest variation in mean bond length for zero distortion, e.g. Li(+) in

  19. Bond-length distributions for ions bonded to oxygen: alkali and alkaline-earth metals.

    Science.gov (United States)

    Gagné, Olivier Charles; Hawthorne, Frank Christopher

    2016-08-01

    Bond-length distributions have been examined for 55 configurations of alkali-metal ions and 29 configurations of alkaline-earth-metal ions bonded to oxygen, for 4859 coordination polyhedra and 38 594 bond distances (alkali metals), and for 3038 coordination polyhedra and 24 487 bond distances (alkaline-earth metals). Bond lengths generally show a positively skewed Gaussian distribution that originates from the variation in Born repulsion and Coulomb attraction as a function of interatomic distance. The skewness and kurtosis of these distributions generally decrease with increasing coordination number of the central cation, a result of decreasing Born repulsion with increasing coordination number. We confirm the following minimum coordination numbers: ([3])Li(+), ([3])Na(+), ([4])K(+), ([4])Rb(+), ([6])Cs(+), ([3])Be(2+), ([4])Mg(2+), ([6])Ca(2+), ([6])Sr(2+) and ([6])Ba(2+), but note that some reported examples are the result of extensive dynamic and/or positional short-range disorder and are not ordered arrangements. Some distributions of bond lengths are distinctly multi-modal. This is commonly due to the occurrence of large numbers of structure refinements of a particular structure type in which a particular cation is always present, leading to an over-representation of a specific range of bond lengths. Outliers in the distributions of mean bond lengths are often associated with anomalous values of atomic displacement of the constituent cations and/or anions. For a sample of ([6])Na(+), the ratio Ueq(Na)/Ueq(bonded anions) is partially correlated with 〈([6])Na(+)-O(2-)〉 (R(2) = 0.57), suggesting that the mean bond length is correlated with vibrational/displacement characteristics of the constituent ions for a fixed coordination number. Mean bond lengths also show a weak correlation with bond-length distortion from the mean value in general, although some coordination numbers show the widest variation in mean bond length for zero distortion, e.g. Li(+) in

  20. Ligase I and ligase III mediate the DNA double-strand break ligation in alternative end-joining.

    Science.gov (United States)

    Lu, Guangqing; Duan, Jinzhi; Shu, Sheng; Wang, Xuxiang; Gao, Linlin; Guo, Jing; Zhang, Yu

    2016-02-01

    In eukaryotes, DNA double-strand breaks (DSBs), one of the most harmful types of DNA damage, are repaired by homologous repair (HR) and nonhomologous end-joining (NHEJ). Surprisingly, in cells deficient for core classic NHEJ factors such as DNA ligase IV (Lig4), substantial end-joining activities have been observed in various situations, suggesting the existence of alternative end-joining (A-EJ) activities. Several putative A-EJ factors have been proposed, although results are mostly controversial. By using a clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) system, we generated mouse CH12F3 cell lines in which, in addition to Lig4, either Lig1 or nuclear Lig3, representing the cells containing a single DNA ligase (Lig3 or Lig1, respectively) in their nucleus, was completely ablated. Surprisingly, we found that both Lig1- and Lig3-containing complexes could efficiently catalyze A-EJ for class switching recombination (CSR) in the IgH locus and chromosomal deletions between DSBs generated by CRISPR/Cas9 in cis-chromosomes. However, only deletion of nuclear Lig3, but not Lig1, could significantly reduce the interchromosomal translocations in Lig4(-/-) cells, suggesting the unique role of Lig3 in catalyzing chromosome translocation. Additional sequence analysis of chromosome translocation junction microhomology revealed the specificity of different ligase-containing complexes. The data suggested the existence of multiple DNA ligase-containing complexes in A-EJ. PMID:26787905

  1. Continuing bonds and grief : a prospective analysis

    NARCIS (Netherlands)

    Boelen, Paul A; Stroebe, Margaret S; Schut, Henk A W; Zijerveld, Annemieke M

    2006-01-01

    Using data of 56 bereaved individuals, this study examined associations of various manifestations of continuing bonds, assessed at 7-12 months post-loss, with concurrent and prospective (9 months later) symptoms of grief and depression. Among other things it was found that, independent of initial sy

  2. Ultrasonic power features of wire bonding and thermosonic flip chip bonding in microelectronics packaging

    Institute of Scientific and Technical Information of China (English)

    LI Jun-hui; HAN Lei; ZHONG Jue

    2008-01-01

    The driving voltage and current signals of piezoeeramie transducer (PZT) were measured directly by designing circuits from ultrasonic generator and using a data acquisition software system. The input impedance and power of PZT were investigated by using root mean square (RMS) calculation. The vibration driven by high frequency was tested by laser Doppler vibrometer (PSV-400-M2). And the thermosonic bonding features were observed by scanning electron microscope (JSM-6360LV). The results show that the input power of bonding is lower than that of no load. The input impedance of bonding is greater than that of no load.Nonlinear phase, plastic flow and expansion period, and strengthening bonding process are shown in the impedance and power curves. The ultrasonic power is in direct proportion to the vibration displacement driven by the power, and greater displacements driven by high power (5W) result in welding failure phenomena, such as crack, break, and peeling off in wedge bonding. For thermosonic flip chip bonding, the high power decreases position precision of bonding or results in slippage and rotation phenomena of bumps. To improve reliability and precision of thermosonic bonding, the low ultrasonic power (about 1-5W) should be chosen.

  3. A novel bonding method for fabrication of PET planar nanofluidic chip with low dimension loss and high bonding strength

    International Nuclear Information System (INIS)

    Plastic planar nanofluidic chips are becoming increasingly important for biological and chemical applications. However, the majority of the present bonding methods for planar nanofluidic chips suffer from high dimension loss and low bonding strength. In this work, a novel thermal bonding technique based on O2 plasma and ethanol treatment was proposed. With the assistance of O2 plasma and ethanol, the PET (polyethylene terephthalate) planar nanofluidic chip can be bonded at a low bonding temperature of 50 °C. To increase the bonding rate and bonding strength, the O2 plasma parameters and thermal bonding parameters were optimized during the bonding process. The tensile test indicates that the bonding strength of the PET planar nanofluidic chip can reach 0.954 MPa, while the auto-fluorescence test demonstrates that there is no leakage or blockage in any of the bonded micro- or nanochannels. (paper)

  4. Development and applications of rectangular box-type explosively bonded structures for high-heat-load beamline components

    Science.gov (United States)

    Shu, D.; Chang, J.; Kuzay, T. M.; Brasher, D. G.

    2001-07-01

    Explosive bonding technology is a good choice to join dissimilar materials, such as 304L stainless steel and GlidCop AL-15, and is used extensively in making the advanced photon source (APS) high-heat-load beamline and front-end components. It is a bonding method in which the controlled energy of a detonating explosive is used to create a metallurgical bond between two or more similar or dissimilar materials. In recent years, special explosive bonding units with rectangular box-type joints were developed for the APS new high-heat-load beamline components. Based on this new technique, the box form of the component could be built in two halves first, then welded together. Therefore, beamline designers have more freedom to optimize the cooling surface geometry.

  5. Joining, Leaving, and Staying in the American Indian/Alaska Native Race Category Between 2000 and 2010.

    Science.gov (United States)

    Liebler, Carolyn A; Bhaskar, Renuka; Porter, Sonya R

    2016-04-01

    Conceptualizing and operationalizing American Indian populations is challenging. Each census for decades has seen the American Indian population increase substantially more than expected, with indirect and qualitative evidence that this is due to changes in individuals' race responses. We apply uniquely suited (but not nationally representative) linked data from the 2000 and 2010 decennial censuses (N = 3.1 million) and the 2006-2010 American Community Survey (N = 188,131) to address three research questions. First, to what extent do American Indian people have different race responses across data sources? We find considerable race response change, especially among multiple-race and/or Hispanic American Indians. Second, how are people who change responses different from or similar to those who do not? We find three sets of American Indians: those who (1) had the same race and Hispanic responses in 2000 and 2010, (2) moved between single-race and multiple-race American Indian responses, and (3) added or dropped the American Indian response, thus joining or leaving the enumerated American Indian population. People in groups (1) and (2) were relatively likely to report a tribe, live in an American Indian area, report American Indian ancestry, and live in the West. Third, how are people who join a group different from or similar to those who leave it? Multivariate models show general similarity between joiners and leavers in group (1) and in group (2). Population turnover is hidden in cross-sectional comparisons; people joining each subpopulation of American Indians are similar in number and characteristics to those who leave it. PMID:26988712

  6. Laser assisted and hermetic room temperature bonding based on direct bonding technology

    Science.gov (United States)

    Haneveld, Jeroen; Tijssen, Peter; Oonk, Johannes; Olde Riekerink, Mark; Tigelaar, Hildebrand; van't Oever, Ronny; Blom, Marko

    2014-03-01

    A novel method for laser assisted room temperature bonding of two substrates is presented. The method enables the packaging of delicate (bio)structures and/or finished (MEMS) devices, as there is no need for a high temperature annealing process. This also allows the bonding of two substrates with non-matching thermal expansion coefficients. The basis of the presented technology is the ability to create a direct pre-bond between two substrates. These can be two glass substrates, of which one has a thin film metal coating (e.g. Cr. Ti, Ta, Au…), or a silicon-glass combination. After (aligned) pre-bonding of the two wafers, a laser (e.g. a Nd:YAG laser) is used to form a permanent bond line on the bond interface, using the metal layer as a light absorber (or the silicon, in the case of a glass-silicon combination). The permanent bond line width is in the order of 10-50μm. The use of a laser to form the permanent bond ensures a hermetic sealing of the total package; a distinctive advantage over other, more conventional methods of room temperature bonding (e.g. adhesive bonding). He-leak testing showed leak rates in the order of 10-9 mbar l/s. This meets the failure criteria of the MIL-STD-883H standard of 5x10-8 mbar l/s. An added functionality of the proposed method is the possibility to create electrical circuitry on the bond interface, using the laser to modify the metal interlayer, rendering it electrically non-conductive. Biocompatible packages are also possible, by choosing the appropriate interlayer material. This would allow for the fabrication of implantable packages.

  7. Composite bonding to stainless steel crowns using a new universal bonding and single-bottle systems.

    Science.gov (United States)

    Hattan, Mohammad Ali; Pani, Sharat Chandra; Alomari, Mohammad

    2013-01-01

    Aim. The aim of this study is to evaluate the shear bond strength of nanocomposite to stainless steel crowns using a new universal bonding system. Material and Methods. Eighty (80) stainless steel crowns (SSCs) were divided into four groups (20 each). Packable nanocomposite was bonded to the lingual surface of the crowns in the following methods: Group A without adhesive (control group), Group B using a new universal adhesive system (Scotchbond Universal Adhesive, 3M ESPE, Seefeld, Germany), and Group C and Group D using two different brands of single-bottle adhesive systems. Shear bond strengths were calculated and the types of failure also were recorded. Results. The shear strength of Group B was significantly greater than that of other groups. No significant differences were found between the shear bond strengths of Groups C and D. The control group had significantly lower shear bond strength (P steel crowns using the new universal bonding agent (Scotchbond Universal Adhesive, 3M ESPE, Seefeld, Germany) show significantly greater shear bond strengths and fewer adhesive failures when compared to traditional single-bottle systems.

  8. The Join-Up Meeting

    Science.gov (United States)

    Cameron, W. Scott

    2002-01-01

    I recently took on a new assignment and, as is my norm, I scheduled a series of one-hour, 1:1 join-up meetings with the various lead personnel on the team and their hierarchy. During one of these meetings, the person I was meeting with informed me how pleasantly surprised she was that I had scheduled this meeting as very few individuals took the time anymore to have them. I was shocked. I was taught that establishing a 1:1 relationship with the people on your team is critical to the project's success. This was the first time I'd heard anything like this about join-up meetings. I filed this feedback away. Later I was talking to my project manager-mentor, and he indicated he had finished his join-up meetings with every person in his new organization. He also indicated his predecessor had conducted few, if any, join-up meetings. Again, I was shocked. When I reflected on these two experiences, I realized a very negative trend might be emerging in our fast-paced, schedule-driven, 500-e-mail-per-day, cell-phone -ringing, 24/7 -communication, multi-tasking work lives: NO FACE TIME! Face time is what you spend with people to talk about the project you are working on, their expectations of you, your expectations of them, your hierarchy's expectations about each of you, and/or-last but certainly not least-what each of you plans on achieving during the project. A 1:1, face-to-face, join-up meeting is the only way I know to build solid trust between the project manager and the team members and their hierarchy.

  9. Effect of bonding time on joint properties of vacuum brazed WC - Co hard metal/carbon steel using stacked Cu and Ni alloy as insert metal

    Energy Technology Data Exchange (ETDEWEB)

    Lee, W.B.; Jung, S.B. [Sungkyunkwan Univ., Dept. of Advanced Materials Engineering, Suwon, Kyounggi-do (Korea); Kwon, B.D. [Seoul Technical High School, Dept. of Metallurgy, Seoul (Korea)

    2004-11-15

    Hard metal WC - Co and carbon steel were successfully joined using double layered Cu alloy and amorphous Ni alloy as inert metal and an oil cooling method after brazing. Defects such as cracks and voids were not formed near the bonded zone. This result means that double layered insert metals and oil cooling minimised the residual stress near the bonded zone after brazing. The shear strength of the joints decreased with increasing bond time. The reasons why the shear strength decreased as bond time increased could be many, including shape of the interface, formation and growth of brittle intermetallic compounds, and coarsening of WC particles near the bond zone. The maximum shear strength of the joints was 310 MPa under conditions 0.6 ks bond time and 8 wt-%Co content in the WC hard alloy. (Author)

  10. INTEREST RATES AND CURRENCIES EFFECTS ON ISLAMIC AND CONVENTIONAL BONDS

    OpenAIRE

    Ghazali Syamni; Husaini Husaini

    2011-01-01

    Bond markets have not been well developed in emerging countries. Realizing its important role, especially after the 1997 crises and the islamic economics development, emerging countries have started to develop such markets. This research examines the effect of interest rates and currencies on Islamic and conventional bonds in Bursa Malaysia. The analysis on Islamic bonds shows that interest rates and currencies do not influence Islamic bonds, which supports the prohibition of interest in Isla...

  11. Special event launches new partnership. IAEA and NFCR join forces to fight cancer in developing world

    International Nuclear Information System (INIS)

    Full text: IAEA Director General and Nobel Laureate Mohamed ElBaradei will join more than 100 leading public figures, philanthropists and cancer experts at the United Nations Headquarters in New York on 29 October to mark the launch of a new partnership between the IAEA and the US based National Foundation for Cancer Research (NFCR). Through this partnership, and the endowment fund called the PACT Fund at NFCR, Americans can support the IAEA and its partners in helping poor countries to combat the looming cancer epidemic. 'The IAEA has long provided radiotherapy machines and expertise to developing countries, but the growing cancer crisis cannot be fought with radiotherapy alone,' says Mohamed ElBaradei. 'Our Programme of Action for Cancer Therapy (PACT), which draws on the Agency's long experience in radiation therapy, is building international partnerships to assist in cancer prevention, early detection, treatment and palliative care. Now, through the PACT Fund at NFCR, Americans have the opportunity to support these efforts and bring hope to millions of cancer patients in developing nations.' According to the World Health Organization (WHO), the world is on the brink of a cancer crisis. New cases are expected to double to more than 16 million a year by 2020, unless action is taken now. Hardest hit will be low-income countries, whose health systems are already overburdened by infectious diseases such as HIV/AIDS, Tuberculosis and Malaria. PACT, which was created within the IAEA in 2004, is forging international partnerships with other cancer organizations in both the public and private sectors. Together with partners such as WHO, the American Cancer Society (ACS), the National Cancer Institute (NCI) and the International Agency for Research on Cancer (IARC), it has established pilot projects called Model Demonstration Sites (PMDS) in six countries (Albania, Nicaragua, Sri Lanka, Tanzania, Vietnam and Yemen) to develop and implement comprehensive, integrated

  12. Stress relaxation and bonding in Si3N4/MA6000 joints by reactive interlayers

    Science.gov (United States)

    Frisch, A.; Kaysser, W. A.; Zhang, W.; Petzow, G.

    Diffusion bonding of Si3N4 to the new generation of ODS-superalloys, such as MA6000, may yield strongly joined metal-ceramic systems for high-temperature applications. Si3N4 has been diffusion bonded to MA6000 during HIP at 100 MPa at 1100-1300 C. Stresses caused by the large thermal mismatch were reduced by multiphase interlayers. To promote the chemical adhesion, reactive and adhesive interlayers were used at the metal-ceramic interface which, in the absence of such layers, fail at low stresses. It has been shown that, during reactive bonding, brittle phases are frequently formed at the interfaces which may lead to a failure of the joint. The reduce of thermal stresses by thin soft interlayers is very limited but can be obtained by a microcrack-induced stress relaxation mechanism. During adhesive diffusion bonding, the mechanical strength of the bond is limited by the stress state and the strength of the ceramic component.

  13. Amidated joining peptide in the human pituitary, gut, adrenal gland and bronchial carcinoids. Immunocytochemical and immunochemical evidence

    DEFF Research Database (Denmark)

    Bjartell, A; Fenger, M; Ekman, R;

    1990-01-01

    The distribution of the proopiomelanocortin-derivated amidated joining peptide (JP-N) was examined in the human pituitary gland, adrenal gland, gut and in three bronchial carcinoids. Double immunostaining showed coexistence of immunoreactive JP-N and other proopiomelanocortin derivatives, e......-N, respectively, but under reduced conditions most of the immunoreactive material appeared as of low molecular weight in both extracts. In conclusion, immunoreactive JP-N is a major product from the processing of proopiomelanocortin in human extrapituitary tissues. The molecular forms of immunoreactive JP...

  14. Innovative Structural and Joining Concepts for Lightweight Design of Heavy Vehicle Systems

    Energy Technology Data Exchange (ETDEWEB)

    Prucz, Jacky C; Shoukry, Samir N; William, Gergis W; Evans, Thomas H

    2006-09-30

    The extensive research and development effort was initiated by the U.S. Department of Energy (DOE) in 2002 at West Virginia University (WVU) in order to investigate practical ways of reducing the structural weight and increasing the durability of heavy vehicles through the judicious use of lightweight composite materials. While this project was initially focused on specific Metal Matrix Composite (MMC) material, namely Aluminum/Silicon Carbide (Al/SiC) commercially referenced as ''LANXIDE'', the current research effort was expanded from the component level to the system level and from MMC to other composite material systems. Broadening the scope of this research is warranted not only by the structural and economical deficiencies of the ''LANXIDE'' MMC material, but also by the strong coupling that exists between the material and the geometric characteristics of the structure. Such coupling requires a truly integrated design approach, focused on the heaviest sections of a van trailer. Obviously, the lightweight design methods developed in this study will not be implemented by the commercial industry unless the weight savings are indeed impressive and proven to be economically beneficial in the context of Life Cycle Costs (LCC). ''Bulk Haul'' carriers run their vehicles at maximum certified weight, so that each pound saved in structural weight would translate into additional pound of cargo, and fewer vehicles necessary to transport a given amount of freight. It is reasonable to ascertain that a typical operator would be ready to pay a premium of about $3-4 for every additional pound of cargo, or every pound saved in structural weight. The overall scope of this project is to devise innovative, lightweight design and joining concepts for heavy vehicle structures, including cost effective applications of components made of metal matrix composite (MMC) and other composite materials in selected sections of such

  15. Efficient Joins with Compressed Bitmap Indexes

    Energy Technology Data Exchange (ETDEWEB)

    Computational Research Division; Madduri, Kamesh; Wu, Kesheng

    2009-08-19

    We present a new class of adaptive algorithms that use compressed bitmap indexes to speed up evaluation of the range join query in relational databases. We determine the best strategy to process a join query based on a fast sub-linear time computation of the join selectivity (the ratio of the number of tuples in the result to the total number of possible tuples). In addition, we use compressed bitmaps to represent the join output compactly: the space requirement for storing the tuples representing the join of two relations is asymptotically bounded by min(h; n . cb), where h is the number of tuple pairs in the result relation, n is the number of tuples in the smaller of the two relations, and cb is the cardinality of the larger column being joined. We present a theoretical analysis of our algorithms, as well as experimental results on large-scale synthetic and real data sets. Our implementations are efficient, and consistently outperform well-known approaches for a range of join selectivity factors. For instance, our count-only algorithm is up to three orders of magnitude faster than the sort-merge approach, and our best bitmap index-based algorithm is 1.2x-80x faster than the sort-merge algorithm, for various query instances. We achieve these speedups by exploiting several inherent performance advantages of compressed bitmap indexes for join processing: an implicit partitioning of the attributes, space-efficiency, and tolerance of high-cardinality relations.

  16. Authenticated join processing in outsourced databases

    KAUST Repository

    Yang, Yin

    2009-01-01

    Database outsourcing requires that a query server constructs a proof of result correctness, which can be verified by the client using the data owner\\'s signature. Previous authentication techniques deal with range queries on a single relation using an authenticated data structure (ADS). On the other hand, authenticated join processing is inherently more complex than ranges since only the base relations (but not their combination) are signed by the owner. In this paper, we present three novel join algorithms depending on the ADS availability: (i) Authenticated Indexed Sort Merge Join (AISM), which utilizes a single ADS on the join attribute, (ii) Authenticated Index Merge Join (AIM) that requires an ADS (on the join attribute) for both relations, and (iii) Authenticated Sort Merge Join (ASM), which does not rely on any ADS. We experimentally demonstrate that the proposed methods outperform two benchmark algorithms, often by several orders of magnitude, on all performance metrics, and effectively shift the workload to the outsourcing service. Finally, we extend our techniques to complex queries that combine multi-way joins with selections and projections. ©2009 ACM.

  17. A new approach to joining of bulk copper using microwave energy

    International Nuclear Information System (INIS)

    Research highlights: → Joining of bulk copper with a sandwich layer using 2.45 GHz microwaves at 900 W. → Melting of sandwich layer and metallurgical bonding with bulk surfaces. → Mechanism of joining using microwave hybrid heating is explained. → Tensile strength and elongation of microwave induced joints are monitored. → Failure mechanisms of microwave induced joints are studied. -- Abstract: Metallurgical joining of high thermal conductivity materials like copper has been technically challenging. This paper illustrates a novel method for joining of bulk metallic materials through microwave heating. Joining of copper in bulk form has been carried out using microwave energy in a multimode applicator at 2.45 GHz and 900 W. Charcoal was used as susceptor material to facilitate microwave hybrid heating (MHH). Copper in coin and plate forms have been successfully joined through microwave heating within 900 s of exposure time. A sandwich layer of copper powder with approximately 0.5 mm thickness was introduced between the two candidate surfaces. Near complete melting of the powder particles in the sandwich layer does take place during the microwave exposure leading to metallurgical bonding of the bulk surfaces. Characterisation of the joints has been carried out through microstructure study, elemental analysis, phase analysis, microhardness survey, porosity measurement and tensile strength testing. X-ray diffraction (XRD) pattern indicates that some copper powder particles got transformed into copper oxides. XRD analysis also reveals that the dominant orientation (3 1 1) in starting copper powder got transformed into a preferential orientation (1 1 1) in the joint. A dense uniform microstructure with good metallurgical bonds between the sandwich layer and the interface was obtained. The hardness of the joint area was observed to be 78 ± 7 Hv, while the porosity in the joint was observed to be 1.92%. Strength character of the copper joints shows approximately

  18. Phase formation at bonded vanadium and stainless steel interfaces

    International Nuclear Information System (INIS)

    The interface between vanadium bonded to stainless steel was studies to determine whether a brittle phase formed during three joining operations. Inertia friction welds between V and 21-6-9 stainless steel were examined using TEM. In the as-welded condition, a continuous, polygranular intermetallic layer about 0.25 μm thick was present at the interface. This layer grew to about 50 μm thick during heat treatment at 1000 degrees C for two hours. Analysis of electron diffraction patterns confirmed that this intermetallic was the ω phase. The interface between vanadium and type 304, SANDVIK SAF 2205, and 21-6-9 stainless steel bonded by a co-extrusion process had intermetallic particles at the interface in the as-extruded condition. Heat treatment at 1000 degrees C for two hours caused these particles to grow into continuous layers in all three cases. Based on the appearance, composition and hardness of this interfacial intermetallic, it was also concluded to be ω phase. Bonding V to type 430 stainless steel by co-extrusion caused V-rich carbides to form at the interface due to the higher concentration of C in the type 430 than in the other stainless steels investigated. The carbide particles initially present grew into a continuous layer during a two-hour heat treatment at 1000 degrees C. Co-hipping 21-6-9 stainless steel tubing with V rod resulted in slightly more concentric specimens than the co-extruded ones, but a continuous layer of the ω phase formed during the hipping operation. This brittle layer could initiate failure during subsequent forming operations. The vanadium near the stainless steel interface in the co-extruded and co-hipped tubing in some cases was harder than before heat treatment. It was concluded that this hardening was due to thermal straining during cooling following heat treatment and that thermal strains might present a greater problem than seen here when longer tubes are used in actual applications

  19. Microstructure and properties of hot roll bonding layer of dissimilar metals. 2. Bonding interface microstructure of Zr/stainless steel by hot roll bonding and its controlling

    International Nuclear Information System (INIS)

    The hot roll bonding of zirconium and stainless steel inserted with tantalium was investigated using the newly developed rolling mill. The effect of hot rolling temperatures of zirconium/stainless steel joints on bonding interface structure was evaluated. Intermetallic compound layer containing cracks was observed at the bonding interface between stainless steel and tantalium when the rolling temperature was above 1373K. The hardness of the bonding layer of zirconium and tantalium bonded above 1273K was higher than tantalium or zirconium base metal in spite of absence of intermetallic compound. The growth of reaction layer at the stainless steel and tantalium interface and at the tantalium and zirconium interface was conforming a parabolic low when that was isothermally heated after hot roll bonding, and the growth rate was almost same as that of static diffusion bonding without using hot roll bonding process. It is estimated that the strain caused by hot roll bonding gives no effect on the growth of reaction layer. It was confirmed that the dissimilar joint of zirconium and stainless steel with insert of tantalium having the sound bonding interface were obtained at the suitable bonding temperature of 1173K by the usage of the newly developed hot roll bonding process. (author)

  20. Atomic bonding between metal and graphene

    KAUST Repository

    Wang, Hongtao

    2013-03-07

    To understand structural and chemical properties of metal-graphene composites, it is crucial to unveil the chemical bonding along the interface. We provide direct experimental evidence of atomic bonding between typical metal nano structures and graphene, agreeing well with density functional theory studies. Single Cr atoms are located in the valleys of a zigzag edge, and few-atom ensembles preferentially form atomic chains by self-assembly. Low migration barriers lead to rich dynamics of metal atoms and clusters under electron irradiation. We demonstrate no electron-instigated interaction between Cr clusters and pristine graphene, though Cr has been reported to be highly reactive to graphene. The metal-mediated etching is a dynamic effect between metal clusters and pre-existing defects. The resolved atomic configurations of typical nano metal structures on graphene offer insight into modeling and simulations on properties of metal-decorated graphene for both catalysis and future carbon-based electronics. © 2013 American Chemical Society.

  1. Effect of clearfil protect bond and transbond plus self-etch primer on shear bond strength of orthodontic brackets

    Directory of Open Access Journals (Sweden)

    S Hamid Raji

    2011-01-01

    Conclusion: The shear bond strength of clearfil protect bond and transbond plus self-etch primer was enough for bonding the orthodontic brackets. The mode of failure of bonded brackets with these two self-etch primers is safe for enamel.

  2. Bond return predictability in expansions and recessions

    DEFF Research Database (Denmark)

    Engsted, Tom; Møller, Stig Vinther; Jensen, Magnus David Sander

    We document that over the period 1953-2011 US bond returns are predictable in expansionary periods but unpredictable during recessions. This result holds in both in-sample and out-of-sample analyses and using both univariate regressions and combination forecasting techniques. A simulation study...... shows that our tests have power to reject unpredictability in both expansions and recessions. To judge the economic significance of the results we compute utility gains for a meanvariance investor who takes the predictability patterns into account and show that utility gains are positive in expansions...... but negative in recessions. The results are also consistent with tests showing that the expectations hypothesis of the term structure holds in recessions but not in expansions. However, the results for bonds are in sharp contrast to results for stocks showing that stock returns are predictable in recessions...

  3. Ownership of Australian Equities and Corporate Bonds

    OpenAIRE

    Susan Black; Joshua Kirkwood

    2010-01-01

    Australian financial and non-financial companies tap capital markets – particularly equity and bond markets – to source funds from households, foreign investors and domestic institutional investors. Foreign investors supply around half of these funds, with institutional investors providing most of the remainder; households’ direct holdings are comparatively modest. During the financial crisis, foreign investors’ appetite for Australian assets remained strong, underpinned by the streng...

  4. Strength and leak testing of plasma activated bonded interfaces

    DEFF Research Database (Denmark)

    Visser, M.M.; Weichel, Steen; Reus, Roger De;

    2002-01-01

    Bond strength and hermeticity of plasma activated bonded (PAB) Si-Si interfaces are reported. Bonding of 100 mm Si(1 0 0) wafers was performed. An average bond strength of 9.0+/-3.9 MPa was achieved without performing any annealing steps. Cavities bonded in vacuum were found to be hermetic based ......-ionised water (DIW), 24 h in 2.5% HF, 24 h in acetone and 60 s in a resist developer. By analysing the thin silicon oxide present on the surfaces to be bonded with optical methods, the influence of pre-cleaning and activation process parameters was investigated....

  5. Repair Bond Strength of Aged Resin Composite after Different Surface and Bonding Treatments

    Directory of Open Access Journals (Sweden)

    Michael Wendler

    2016-07-01

    Full Text Available The aim of this study was to compare the effect of different mechanical surface treatments and chemical bonding protocols on the tensile bond strength (TBS of aged composite. Bar specimens were produced using a nanohybrid resin composite and aged in distilled water for 30 days. Different surface treatments (diamond bur, phosphoric acid, silane, and sandblasting with Al2O3 or CoJet Sand, as well as bonding protocols (Primer/Adhesive were used prior to application of the repair composite. TBS of the specimens was measured and the results were analyzed using analysis of variance (ANOVA and the Student–Newman–Keuls test (α = 0.05. Mechanically treated surfaces were characterized under SEM and by profilometry. The effect of water aging on the degree of conversion was measured by means of FTIR-ATR spectroscopy. An important increase in the degree of conversion was observed after aging. No significant differences in TBS were observed among the mechanical surface treatments, despite variations in surface roughness profiles. Phosphoric acid etching significantly improved repair bond strength values. The cohesive TBS of the material was only reached using resin bonding agents. Application of an intermediate bonding system plays a key role in achieving reliable repair bond strengths, whereas the kind of mechanical surface treatment appears to play a secondary role.

  6. Unusual H-Bond Topology and Bifurcated H-bonds in the 2-Fluoroethanol Trimer.

    Science.gov (United States)

    Thomas, Javix; Liu, Xunchen; Jäger, Wolfgang; Xu, Yunjie

    2015-09-28

    By using a combination of rotational spectroscopy and ab initio calculations, an unusual H-bond topology was revealed for the 2-fluoroethanol trimer. The trimer exhibits a strong heterochiral preference and adopts an open OH⋅⋅⋅OH H-bond topology while utilizing two types of bifurcated H-bonds involving organic fluorine. This is in stark contrast to the cyclic OH⋅⋅⋅OH H-bond topology adopted by trimers of water and other simple alcohols. The strengths of different H-bonds in the trimer were analyzed by using the quantum theory of atoms in molecules. The study showcases a remarkable example of a chirality-induced switch in H-bond topology in a simple transient chiral fluoroalcohol. It provides important insight into the H-bond topologies of small fluoroalcohol aggregates, which are proposed to play a key role in protein folding and in enantioselective reactions and separations where fluoroalcohols serve as a (co)solvent.

  7. Grandmothering life histories and human pair bonding.

    Science.gov (United States)

    Coxworth, James E; Kim, Peter S; McQueen, John S; Hawkes, Kristen

    2015-09-22

    The evolution of distinctively human life history and social organization is generally attributed to paternal provisioning based on pair bonds. Here we develop an alternative argument that connects the evolution of human pair bonds to the male-biased mating sex ratios that accompanied the evolution of human life history. We simulate an agent-based model of the grandmother hypothesis, compare simulated sex ratios to data on great apes and human hunter-gatherers, and note associations between a preponderance of males and mate guarding across taxa. Then we explore a recent model that highlights the importance of mating sex ratios for differences between birds and mammals and conclude that lessons for human evolution cannot ignore mammalian reproductive constraints. In contradiction to our claim that male-biased sex ratios are characteristically human, female-biased ratios are reported in some populations. We consider the likelihood that fertile men are undercounted and conclude that the mate-guarding hypothesis for human pair bonds gains strength from explicit links with our grandmothering life history. PMID:26351687

  8. Nonhomologous end joining of complex DNA double-strand breaks with proximal thymine glycol and interplay with base excision repair.

    Science.gov (United States)

    Almohaini, Mohammed; Chalasani, Sri Lakshmi; Bafail, Duaa; Akopiants, Konstantin; Zhou, Tong; Yannone, Steven M; Ramsden, Dale A; Hartman, Matthew C T; Povirk, Lawrence F

    2016-05-01

    DNA double-strand breaks induced by ionizing radiation are often accompanied by ancillary oxidative base damage that may prevent or delay their repair. In order to better define the features that make some DSBs repair-resistant, XLF-dependent nonhomologous end joining of blunt-ended DSB substrates having the oxidatively modified nonplanar base thymine glycol at the first (Tg1), second (Tg2), third (Tg3) or fifth (Tg5) positions from one 3' terminus, was examined in human whole-cell extracts. Tg at the third position had little effect on end-joining even when present on both ends of the break. However, Tg as the terminal or penultimate base was a major barrier to end joining (>10-fold reduction in ligated products) and an absolute barrier when present at both ends. Dideoxy trapping of base excision repair intermediates indicated that Tg was excised from Tg1, Tg2 and Tg3 largely if not exclusively after DSB ligation. However, Tg was rapidly excised from the Tg5 substrate, resulting in a reduced level of DSB ligation, as well as slow concomitant resection of the opposite strand. Ligase reactions containing only purified Ku, XRCC4, ligase IV and XLF showed that ligation of Tg3 and Tg5 was efficient and only partially XLF-dependent, whereas ligation of Tg1 and Tg2 was inefficient and only detectable in the presence of XLF. Overall, the results suggest that promoting ligation of DSBs with proximal base damage may be an important function of XLF, but that Tg can still be a major impediment to repair, being relatively resistant to both trimming and ligation. Moreover, it appears that base excision repair of Tg can sometimes interfere with repair of DSBs that would otherwise be readily rejoined. PMID:27049455

  9. Homolytic Bond Dissociation Enthalpies of C C and C-H Bonds in Highly Crowded Alkanes

    Institute of Scientific and Technical Information of China (English)

    ZHU Chen; RUI Lei; FU Yao

    2008-01-01

    The homolytic C-C and C--H bond dissociation enthalpyies (BDE) of highly crowded alkanes were calcu- lated by using an ONIOM-G3B3 method. Geometric parameters such as bond length, bond angle and molecular volume were carefully investigated, as most of the acyclic alkanes in this study were not yet synthesized. These pa-rameters reflect the influence of steric effect on BDE. Good correlations were found between the rapid decrease of BDE and the increase of molecular volumes. The correlations can be applied to the prediction of the possible exis-tence of many highly strained compounds.

  10. Modeling, simulation and control of pulsed DE-GMA welding process for joining of aluminum to steel

    Science.gov (United States)

    Zhang, Gang; Shi, Yu; Li, Jie; Huang, Jiankang; Fan, Ding

    2014-09-01

    Joining of aluminum to steel has attracted significant attention from the welding research community, automotive and rail transportation industries. Many current welding methods have been developed and applied, however, they can not precisely control the heat input to work-piece, they are high costs, low efficiency and consist lots of complex welding devices, and the generated intermetallic compound layer in weld bead interface is thicker. A novel pulsed double electrode gas metal arc welding(Pulsed DE-GMAW) method is developed. To achieve a stable welding process for joining of aluminum to steel, a mathematical model of coupled arc is established, and a new control scheme that uses the average feedback arc voltage of main loop to adjust the wire feed speed to control coupled arc length is proposed and developed. Then, the impulse control simulation of coupled arc length, wire feed speed and wire extension is conducted to demonstrate the mathematical model and predict the stability of welding process by changing the distance of contact tip to work-piece(CTWD). To prove the proposed PSO based PID control scheme's feasibility, the rapid prototyping experimental system is setup and the bead-on-plate control experiments are conducted to join aluminum to steel. The impulse control simulation shows that the established model can accurately represent the variation of coupled arc length, wire feed speed and the average main arc voltage when the welding process is disturbed, and the developed controller has a faster response and adjustment, only runs about 0.1 s. The captured electric signals show the main arc voltage gradually closes to the supposed arc voltage by adjusting the wire feed speed in 0.8 s. The obtained typical current waveform demonstrates that the main current can be reduced by controlling the bypass current under maintaining a relative large total current. The control experiment proves the accuracy of proposed model and feasibility of new control scheme

  11. Modeling, Simulation and Control of Pulsed DE-GMA Welding Process for Joining of Aluminum to Steel

    Institute of Scientific and Technical Information of China (English)

    ZHANG Gang; SHI Yu; LI Jie; HUANG Jiankang; FAN Ding

    2014-01-01

    Joining of aluminum to steel has attracted significant attention from the welding research community, automotive and rail transportation industries. Many current welding methods have been developed and applied, however, they can not precisely control the heat input to work-piece, they are high costs, low efficiency and consist lots of complex welding devices, and the generated intermetallic compound layer in weld bead interface is thicker. A novel pulsed double electrode gas metal arc welding(Pulsed DE-GMAW) method is developed. To achieve a stable welding process for joining of aluminum to steel, a mathematical model of coupled arc is established, and a new control scheme that uses the average feedback arc voltage of main loop to adjust the wire feed speed to control coupled arc length is proposed and developed. Then, the impulse control simulation of coupled arc length, wire feed speed and wire extension is conducted to demonstrate the mathematical model and predict the stability of welding process by changing the distance of contact tip to work-piece(CTWD). To prove the proposed PSO based PID control scheme’s feasibility, the rapid prototyping experimental system is setup and the bead-on-plate control experiments are conducted to join aluminum to steel. The impulse control simulation shows that the established model can accurately represent the variation of coupled arc length, wire feed speed and the average main arc voltage when the welding process is disturbed, and the developed controller has a faster response and adjustment, only runs about 0.1 s. The captured electric signals show the main arc voltage gradually closes to the supposed arc voltage by adjusting the wire feed speed in 0.8 s. The obtained typical current waveform demonstrates that the main current can be reduced by controlling the bypass current under maintaining a relative large total current. The control experiment proves the accuracy of proposed model and feasibility of new control scheme

  12. Hole-pin joining structure with fiber-round-hole distribution of lobster cuticle and biomimetic study.

    Science.gov (United States)

    Chen, Bin; Fan, Jinghong; Gou, Jihua; Lin, Shiyun

    2014-12-01

    Observations of the cuticle of the Boston Spiny Lobster using scanning electron microscope (SEM) show that it is a natural biocomposite consisting of chitin fibers and sclerotic-protein matrix with hierarchical and helicoidal structure. The SEM images also indicate that there is a hole-pin joining structure in the cuticle. In this joining structure, the chitin fibers in the neighborhood of the joining holes continuously round the holes to form a fiber-round-hole distribution. The maximum pullout force of the fibers in the fiber-round-hole distribution, which is closely related to the fracture toughness of the cuticle, is investigated and compared with that of the fibers in non-fiber-round-hole distribution based on their representative models. It is revealed that the maximum pullout force of the fibers in the fiber-round-hole distribution is significantly larger than that of the fibers in the non-fiber-round-hole distribution, and that a larger diameter of the hole results in a larger difference in the maximum pullout forces of the fibers between the two kinds of the fiber distributions. Inspired by the fiber-round-hole distribution found in the cuticle, composite specimens with the fiber-round-hole distribution were fabricated with a special mold and process to mirror the fiber-round-hole distribution. The fracture toughness of the biomimetic composite specimens is tested and compared with that of the conventional composite specimens with the non-fiber-round-hole distribution. It is demonstrated that the fracture toughness of the biomimetic composite specimens with the fiber-round-hole distribution is significantly larger than that of the conventional composite specimens with the non-fiber-round-hole distribution.

  13. Issuer Quality and Corporate Bond Returns

    OpenAIRE

    Greenwood, Robin Marc; Hanson, Samuel Gregory

    2013-01-01

    We show that the credit quality of corporate debt issuers deteriorates during credit booms, and that this deterioration forecasts low excess returns to corporate bondholders. The key insight is that changes in the pricing of credit risk disproportionately affect the financing costs faced by low quality firms, so the debt issuance of low quality firms is particularly useful for forecasting bond returns. We show that a significant decline in issuer quality is a more reliable signal of credit ma...

  14. Summary of Dissimilar Metal Joining Trials Conducted by Edison Welding Institute

    International Nuclear Information System (INIS)

    noticeable reaction layer. T-111 was found to have a small reaction layer at the interface with deposited Hastelloy X. Mar M-247 had a reaction layer larger than T-111. Hastelloy X joined well with a substrate of the same alloy, and throughout the experiments was found to have a density of ∼99%, based on metallographic observations of porosity in the deposit. Of the three joining methods tested, inertial welding of bar stock appears to be the most mature at this time. MPW may be an attractive alternative due to the potential for high bond integrity, similar to that seen in explosion bonding. However, all three joining methods used in this work will require adaptation in order to join piping and tubing. Further investigations into the change in mechanical properties of these joints with time, temperature, irradiation, and the use of interlayers between the two materials must also be performed

  15. Summary of Dissimilar Metal Joining Trials Conducted by Edison Welding Institute

    Energy Technology Data Exchange (ETDEWEB)

    MJ Lambert

    2005-11-18

    noticeable reaction layer. T-111 was found to have a small reaction layer at the interface with deposited Hastelloy X. Mar M-247 had a reaction layer larger than T-111. Hastelloy X joined well with a substrate of the same alloy, and throughout the experiments was found to have a density of {approx}99%, based on metallographic observations of porosity in the deposit. Of the three joining methods tested, inertial welding of bar stock appears to be the most mature at this time. MPW may be an attractive alternative due to the potential for high bond integrity, similar to that seen in explosion bonding. However, all three joining methods used in this work will require adaptation in order to join piping and tubing. Further investigations into the change in mechanical properties of these joints with time, temperature, irradiation, and the use of interlayers between the two materials must also be performed.

  16. Numerical Modelling and Experimental Investigation of Microsegregation in Al-4.45 wt pct Cu: Effect of Dendrite Joining

    Institute of Scientific and Technical Information of China (English)

    H.B.Dong

    2005-01-01

    A numerical model Alloy/M has been applied to investigate the microsegregation in Al-4.45 wt pct Cu alloy. The calculated data were compared with the experimental measurements for samples solidified at different cooling rates.Discrepancies in solute concentration occur between the experimental observations and calculated results. Reasons for the discrepancies were discussed, and the effect of dendrite joining at a later stage of solidification on the microsegregation was investigated. Calculations that have included this effect showed a better fit with experimental results.

  17. Interfiber bonding and fiber segment activation in paper

    OpenAIRE

    Hannu Paulapuro; Anna K. Vainio

    2007-01-01

    Bonding and activation in paper were studied with the help of laboratory test sheets and common paper strength tests. Different papermaking furnishes and raw material treatments were used to examine the effects they have on bonding and activation. Furthermore, various boundary conditions during drying were included to single out the influence of bonding and activation on paper properties. It was found that bonding is clearly increased by beating of kraft pulp, starch addition, and thermomecha...

  18. Reactive Diffusion Bonding of SiCp/Al Composites by Insert Powder Layers with Eutectic Composition

    Institute of Scientific and Technical Information of China (English)

    Jihua HUANG; Yueling DONG; Jiangang ZHANG; Yun WAN; Guoan ZHOU

    2005-01-01

    Mixed Al-Si and Al-Cu powders were investigated as insert layers to reactive diffusion bond SiCp/6063 metal matrix composite (MMC). The results show that SiCp/6063 MMC joints bonded by the insert layers of the mixed Al-Si and Al-Cu powders have a dense joining layer of high quality. The mass transfer between the bonded materials and insert layers during bonding leads to the hypoeutectic microstructure of the joining layers bonded by both the mixed Al-Si and Al-Cu powders with eutectic composition. At fixed bonding time (temperature), the shear strength of the joints by both insert layers of the mixed Al-Si and Al-Cu powders increases with increasing the bonding temperature (time), but get maxima at bonding temperature 600℃ (time 90 min).

  19. New gravitational formula as a bridge to join the modern physics and the classical physics

    Science.gov (United States)

    Chen, Shao-Guang

    measuring value of one-way velocity of light (H05-0020-08) to replace the infinity value of light speed measured by Galileo in 1607, thereby the mass m in NM will become variable m. Or else, the energy of electron in accelerator should not larger than 0.51Mev which conflict with the experimental fact. According to the variable mass and the definition of force we again get Eq.(1) from NM without hypothesis, i.e., NM is generalized in which Galileo coordinates transformation and the action at a distance will be of no effect. Eq.(1) has more reliable experimental base and generalized NM may be applied to the high-speed and the microscopic conditions. Because of the result of a test of GR with use of a hydrogen-maser frequency standard in a spacecraft launched nearly vertically upward to 10000 km (R. F. C. Vessot et.al., Phys. Rev. Lett. 45, 2081 (1980)), the isotropy of one-way velocity of light had been validated at the 1*10 (-10) level (D2.4-0030-12, H0.1-0009-12, H0.2-0008-12). Again from the Lorentz transformation (H01-0006-08) and the uncertainty principle (H05-0036-10) deduced from the metrical results of Doppler effects, SR and QM, thereby QFT and GR, all become the inferential theorems from generalized NM. Formula (1) is as a bridge to join the modern physics and classical physics. The inertial system (IS) is defined as a linear coordinate system with equal speed, for to judge it yes or not IS we again must measure in a linear coordinate system with equal speed. At the acceleration coordinate to judge IS will make a mistake. So that IS in a logic cycle with self to judge itself. In other words, to determine an IS need another IS, how to judge the first IS? In present measuring precision, we would not find a real IS, Galileo ship concept became as history. The definition of IS in NM had been inherited by SR, GR, QM and QFT, in GR the IS become the local IS. The logic cycle of IS will be a collective problem of the modern physics and the classical physics, and leads to

  20. Join-Graph Propagation Algorithms

    OpenAIRE

    Mateescu, Robert; Kask, Kalev; Gogate, Vibhav; Dechter, Rina

    2014-01-01

    The paper investigates parameterized approximate message-passing schemes that are based on bounded inference and are inspired by Pearl's belief propagation algorithm (BP). We start with the bounded inference mini-clustering algorithm and then move to the iterative scheme called Iterative Join-Graph Propagation (IJGP), that combines both iteration and bounded inference. Algorithm IJGP belongs to the class of Generalized Belief Propagation algorithms, a framework that allowed connections with a...

  1. Prediction of allosteric sites and mediating interactions through bond-to-bond propensities

    CERN Document Server

    Amor, Benjamin R C; Yaliraki, Sophia N; Barahona, Mauricio

    2016-01-01

    Allosteric regulation is central to many biochemical processes. Allosteric sites provide a target to fine-tune protein activity, yet we lack computational methods to predict them. Here, we present an efficient graph-theoretical approach for identifying allosteric sites and the mediating interactions that connect them to the active site. Using an atomistic graph with edges weighted by covalent and non-covalent bond energies, we obtain a bond-to-bond propensity that quantifies the effect of instantaneous bond fluctuations propagating through the protein. We use this propensity to detect the sites and communication pathways most strongly linked to the active site, assessing their significance through quantile regression and comparison against a reference set of 100 generic proteins. We exemplify our method in detail with three well-studied allosteric proteins: caspase-1, CheY, and h-Ras, correctly predicting the location of the allosteric site and identifying key allosteric interactions. Consistent prediction of...

  2. Shear bond strength, failure modes, and confocal microscopy of bonded amalgam restorations.

    Science.gov (United States)

    Cianconi, Luigi; Conte, Gabriele; Mancini, Manuele

    2011-01-01

    This study evaluated the shear bond strength, failure modes, and confocal microscopy of two different amalgam alloy restorations lined with five adhesive systems. Two regular-set high-copper dental amalgam alloys, Amalcap Plus and Valiant Ph.D, and five commercially available adhesive systems were selected. One hundred and twenty freshly-extracted human third molars were used for the study. The results were statistically evaluated using two-factor analysis of variance (ANOVA). The shear bond strength (SBS) of amalgam to dentin was significantly affected by both the adhesive (pValiant Ph.D, 31 of 50 exhibited adhesive failure, and 19 displayed mixed failure. Laser optical microscopy (OM) of the bonded interface revealed the presence of a good hybrid layer was evident in all experimental groups. Higher bond strengths were measured for four of the five adhesives when used in combination with the spherical alloy. PMID:21383518

  3. Bayesian field theoretic reconstruction of bond potential and bond mobility in single molecule force spectroscopy

    CERN Document Server

    Chang, Joshua C; Chou, Tom

    2015-01-01

    Quantifying the forces between and within macromolecules is a necessary first step in understanding the mechanics of molecular structure, protein folding, and enzyme function and performance. In such macromolecular settings, dynamic single-molecule force spectroscopy (DFS) has been used to distort bonds. The resulting responses, in the form of rupture forces, work applied, and trajectories of displacements, have been used to reconstruct bond potentials. Such approaches often rely on simple parameterizations of one-dimensional bond potentials, assumptions on equilibrium starting states, and/or large amounts of trajectory data. Parametric approaches typically fail at inferring complex-shaped bond potentials with multiple minima, while piecewise estimation may not guarantee smooth results with the appropriate behavior at large distances. Existing techniques, particularly those based on work theorems, also do not address spatial variations in the diffusivity that may arise from spatially inhomogeneous coupling to...

  4. Comparison of the microtensile bond strength of different composite core materials and bonding systems to a fiber post (DT Light

    Directory of Open Access Journals (Sweden)

    Lelya Sadighpour

    2013-10-01

    Full Text Available   Background and Aims: Retention and stability of the post and core system is the key factor for success of final restoration . The aim of this study was to evaluate the microtensile bond strength of the different composite core materials and bonding systems to a fiber post.   Materials and Methods: To evaluate the bond strength of the composite resins to a fiber post ( DT light post 60 posts were divided into six groups : group A: Heliomolar Flow + Seal Bond, group B: Heliomolar Flow + SE Bond , group C: Valux Plus + Seal Bond , group D: Valux Plus + SE Bond , group E: Corecem + Seal Bond, group F: Corecem + SE Bond. All samples were thermocycled for 5000 cycles (5-55 0C and cut into four bars for the microtensile bond strength test. Failure modes were identified using a stereomicroscope. Data were analysed using One-way ANOVA and Tukey HSD post hoc test (P<0.05.   Results: The interaction between composite resin materials and bonding systems were positive. The conventional hybrid composite (Valux Plus had significantly higher bond strength compared with the core specific flowable composite (Corecem when Seal Bond was applied as bonding agent (P<0.05. However, when SE Bond was utilized hybrid composite demonstrated significantly lower bond strength than that of other two groups (P<0.05.   Conclusion: The performance of a particular composite is affected by the bonding system that is applied. A single composite resin may have different bond strength when combined with different bonding system.

  5. Shear Bond Strength of Three Orthodontic Bonding Systems on Enamel and Restorative Materials

    Science.gov (United States)

    Ebeling, Jennifer; Schauseil, Michael; Stein, Steffen; Roggendorf, Matthias; Korbmacher-Steiner, Heike

    2016-01-01

    Objective. The aim of this in vitro study was to determine the shear bond strength (SBS) and adhesive remnant index (ARI) score of two self-etching no-mix adhesives (iBond™ and Scotchbond™) on different prosthetic surfaces and enamel, in comparison with the commonly used total etch system Transbond XT™. Materials and Methods. A total of 270 surfaces (1 enamel and 8 restorative surfaces, n = 30) were randomly divided into three adhesive groups. In group 1 (control) brackets were bonded with Transbond XT primer. In the experimental groups iBond adhesive (group 2) and Scotchbond Universal adhesive (group 3) were used. The SBS was measured using a Zwicki 1120™ testing machine. The ARI and SBS were compared statistically using the Kruskal–Wallis test (P ≤ 0.05). Results. Significant differences in SBS and ARI were found between the control group and experimental groups. Conclusions. Transbond XT showed the highest SBS on human enamel. Scotchbond Universal on average provides the best bonding on all other types of surface (metal, composite, and porcelain), with no need for additional primers. It might therefore be helpful for simplifying bonding in orthodontic procedures on restorative materials in patients. If metal brackets have to be bonded to a metal surface, the use of a dual-curing resin is recommended.

  6. Preliminary results for explosion bonding of beryllium to copper

    Energy Technology Data Exchange (ETDEWEB)

    Butler, D.J. [Northwest Technical Industries, Inc., Sequim, WA (United States); Dombrowski, D.E. [Brush Wellman, Inc., Cleveland, OH (United States)

    1995-09-01

    This program was undertaken to determine if explosive bonding is a viable technique for joining beryllium to copper substrates. The effort was a cursory attempt at trying to solve some of the problems associated with explosive bonding beryllium and should not be considered a comprehensive research effort. There are two issues that this program addressed. Can beryllium be explosive bonded to copper substrates and can the bonding take place without shattering the beryllium? Thirteen different explosive bonding iterations were completed using various thicknesses of beryllium that were manufactured with three different techniques.

  7. Detecting variable (V, diversity (D and joining (J gene segment recombination using a two-colour fluorescence system

    Directory of Open Access Journals (Sweden)

    Scott Gina B

    2010-03-01

    Full Text Available Abstract Background Diversity of immunoglobulins and the T cell antigen receptors is achieved via the recombination activating gene (RAG-mediated rearrangement of variable (V, diversity (D and joining (J gene segments, and this underpins the efficient recognition of a seemingly limitless array of antigens. Analysis of V(DJ recombination activity is typically performed using extrachromosomal recombination substrates that are recovered from transfected cells and selected using bacterial transformation. We have developed a two-colour fluorescence-based system that simplifies detection of both deletion and inversion joining events mediated by RAG proteins. Results This system employs two fluorescent reporter genes that differentially mark unrearranged substrates and those that have undergone RAG-mediated deletion or inversion events. The recombination products bear the hallmarks of true V(DJ recombination and activity can be detected using fluorescence microscopy or flow cytometry. Recombination events can be detected without the need for cytotoxic selection of recombination products and the system allows analysis of recombination activity using substrates integrated into the genome. Conclusions This system will be useful in the analysis and exploitation of the V(DJ recombination machinery and suggests that similar approaches could be used to replace expression of one gene with another during lymphocyte development.

  8. Comparison of shear bond strength of amalgam bonded to primary and permanent dentin

    OpenAIRE

    Mahdi S; Bahman S; Arghavan A; Fatemeh M

    2008-01-01

    Amalgam′s non-adhesive characteristics necessitate cavity preparations incorporating retentive features, which often require the removal of non-carious tooth structure. Use of adhesives beneath amalgam restorations, would be helpful to overcome this disadvantage. This study was undertaken to compare the mean shear bond strength of amalgam bonded to primary and permanent dentin, to evaluate the efficacy of amalgam adhesives in pediatric dentistry.27 primary and 28 permanent posterior te...

  9. DISULFIND: A DISULFIDE BONDING STATE AND CYSTEINE CONNECTIVITY PREDICTION SERVER

    OpenAIRE

    Ceroni, A; Passerini, A.; Vullo,A; Frasconi, P.

    2006-01-01

    DISULFIND is a server for predicting the disulfide bonding state of cysteines and their disulfide connectivity starting from sequence alone. Optionally, disulfide connectivity can be predicted from sequence and a bonding state assignment given as input. The output is a simple visualization of the assigned bonding state (with confidence degrees) and the most likely connectivity patterns. The server is available at .

  10. Cooperative effects between tetrel bond and other σ-hole bond interactions: a comparative investigation

    Science.gov (United States)

    Esrafili, Mehdi D.; Nurazar, Roghaye; Mohammadian-Sabet, Fariba

    2015-12-01

    Covalently bonded atoms of Groups IV-VII tend to have anisotropic charge distributions, the electronic densities being less on the extensions of the bonds (σ-holes) than in the intervening regions. These σ-holes often give rise to positive electrostatic potentials through which the atom can interact attractively and highly directionally with negative sites. In this work, cooperative effects between tetrel bond and halogen/chalcogen/pnicogen bond interactions are studied in multi-component YH3M...NCX...NH3 complexes, where Y = F, CN; M = C, Si and X = Cl, SH and PH2. These effects are analysed in detail in terms of the structural, energetic, charge-transfer and electron density properties of the complexes. The nature of the σ-hole bonds is unveiled by quantum theory of atoms in molecules and natural bond orbital theory. A favourable cooperativity is found with values that range between -0.34 and -1.15 kcal/mol. Many-body decomposition of interaction energies indicate that two-body energy term is the most important source of the attraction, which its contribution accounts for 87%-96% of the total interaction energy.

  11. TRF2/RAP1 and DNA-PK mediate a double protection against joining at telomeric ends.

    Science.gov (United States)

    Bombarde, Oriane; Boby, Céline; Gomez, Dennis; Frit, Philippe; Giraud-Panis, Marie-Josèphe; Gilson, Eric; Salles, Bernard; Calsou, Patrick

    2010-05-01

    DNA-dependent protein kinase (DNA-PK) is a double-strand breaks repair complex, the subunits of which (KU and DNA-PKcs) are paradoxically present at mammalian telomeres. Telomere fusion has been reported in cells lacking these proteins, raising two questions: how is DNA-PK prevented from initiating classical ligase IV (LIG4)-dependent non-homologous end-joining (C-NHEJ) at telomeres and how is the backup end-joining (EJ) activity (B-NHEJ) that operates at telomeres under conditions of C-NHEJ deficiency controlled? To address these questions, we have investigated EJ using plasmid substrates bearing double-stranded telomeric tracks and human cell extracts with variable C-NHEJ or B-NHEJ activity. We found that (1) TRF2/RAP1 prevents C-NHEJ-mediated end fusion at the initial DNA-PK end binding and activation step and (2) DNA-PK counteracts a potent LIG4-independent EJ mechanism. Thus, telomeres are protected against EJ by a lock with two bolts. These results account for observations with mammalian models and underline the importance of alternative non-classical EJ pathways for telomere fusions in cells. PMID:20407424

  12. Continuing relationships with the deceased : disentangling bonds and grief

    NARCIS (Netherlands)

    Schut, Henk A W; Stroebe, Margaret S; Boelen, Paul A; Zijerveld, Annemieke M

    2006-01-01

    Some studies of the relationship between continuing bonds and grief intensity have claimed that continuing bonds lead to poor adaptation to bereavement. However, operationalizations of continuing bonds and grief intensity appear to overlap conceptually. Thus, it is still unclear what character the c

  13. Development finance via diaspora bonds track record and potential

    OpenAIRE

    Ketkar, Suhas L.; Ratha, Dilip

    2004-01-01

    A diaspora bond is a debt instrument issued by a country - or potentially, a sub-sovereign entity or a private corporation - to raise financing from its overseas diaspora. Israel and India have raised $35-40 billion using these bonds. Drawing on their experiences, this paper discusses the rationale, methodology, and factors affecting the issuance of diaspora bonds for raising external deve...

  14. A review of joining techniques for SiC{sub f}/SiC composites for first wall applications

    Energy Technology Data Exchange (ETDEWEB)

    Lewinsohn, C.A.; Jones, R.H. [Pacific Northwest National Lab., Richland, WA (United States)

    1998-09-01

    Many methods for joining monolithic and composite silicon carbide are available. Three techniques are candidates for use in fusion energy systems: in-situ displacement reactions, pre-ceramic polymer adhesives, and reaction bonding. None of the methods are currently developed enough to satisfy all of the criteria required, i.e., low temperature fabrication, high strength, and radiation stability. 58 refs.

  15. Various Carbon to Carbon Bond Lengths Inter-related via the Golden Ratio, and their Linear Dependence on Bond Energies

    CERN Document Server

    Heyrovska, Raji

    2008-01-01

    This work presents the relations between the carbon to carbon bond lengths in the single, double and triple bonds and in graphite, butadiene and benzene. The Golden ratio, which was shown to divide the Bohr radius into two parts pertaining to the charged particles, the electron and proton, and to divide inter-atomic distances into their cationic and anionic radii, also plays a role in the carbon-carbon bonds and in the ionic/polar character of those in graphite, butadiene and benzene. Further, the bond energies of the various CC bonds are shown to vary linearly with the bond lengths.

  16. Residual stresses generated during joining of dissimilar alumina-zirconia composites by plastic deformation and its implications on mechanical properties

    International Nuclear Information System (INIS)

    Ceramic bars of zirconia toughened-alumina composites were fabricated by pressureless sintering in air at 1450 deg. C for 4 h. Composite samples were fabricated with two different compositions: zirconia with 60 vol.% alumina (ZT60A) and zirconia with 40 vol.% alumina (ZT40A). Average four-point-bend strengths for the ZT40A and ZT60A were 480 ± 45 MPa and 410 ± 120 MPa, respectively. Three-layered sandwich structures were fabricated by joining two bars of sintered ZT60A with a sintered ZT40A bar. High-temperature plastic joining was accomplished at 1350 deg. C at a strain rate of 5 x 10-6 s-1 and a compressive stress ranging from 30-40 MPa. Bend tests conducted on the layered structure exhibited average strengths of 707 ± 81 MPa. Strength enhancements for the multilayered structure were higher than those predicted by stress analysis. Stress enhancements were compared with the residual stresses measured in the layered sample using X-ray micro-diffraction at the Advance Photon Source (APS). Scanning electron microscopy (SEM) was also conducted to identify the location of failure causing flaws.

  17. Redundant function of DNA ligase 1 and 3 in alternative end-joining during immunoglobulin class switch recombination.

    Science.gov (United States)

    Masani, Shahnaz; Han, Li; Meek, Katheryn; Yu, Kefei

    2016-02-01

    Nonhomologous end-joining (NHEJ) is the major DNA double-strand break (DSB) repair pathway in mammals and resolves the DSBs generated during both V(D)J recombination in developing lymphocytes and class switch recombination (CSR) in antigen-stimulated B cells. In contrast to the absolute requirement for NHEJ to resolve DSBs associated with V(D)J recombination, DSBs associated with CSR can be resolved in NHEJ-deficient cells (albeit at a reduced level) by a poorly defined alternative end-joining (A-EJ) pathway. Deletion of DNA ligase IV (Lig4), a core component of the NHEJ pathway, reduces CSR efficiency in a mouse B-cell line capable of robust cytokine-stimulated CSR in cell culture. Here, we report that CSR levels are not further reduced by deletion of either of the two remaining DNA ligases (Lig1 and nuclear Lig3) in Lig4(-/-) cells. We conclude that in the absence of Lig4, Lig1, and Lig3 function in a redundant manner in resolving switch region DSBs during CSR. PMID:26787901

  18. Students' Perceptions of Parental Bonding Styles and Their Academic Burnout

    Science.gov (United States)

    Shin, Hyojung; Lee, Jayoung; Kim, Boyoung; Lee, Sang Min

    2012-01-01

    This study investigated how parental bonding style affects academic burnout in Korean adolescents. Participants were 447 middle school students, who completed the Parental Bonding Instrument and the Maslach Burnout Inventory-Student Survey. MANCOVA results confirmed that adolescents reporting the optimal bonding parental style, for both mother and…

  19. Joining of silicon carbide using interlayer with matching coefficient of thermal expansion

    International Nuclear Information System (INIS)

    The primary objective of this study is to develop a technique for joining a commercially available Silicon Carbide that gives good room temperature strength and the potential for good high temperature strength. One secondary objective is that the joining technique be adaptable to SiCf/SiC composites and/or Nickel based superalloys, and another secondary objective is that the materials provide good neutron irradiation resistance and low activation for potential application inside nuclear fusion reactors. The joining techniques studied here are: (1) reaction bonding with Al-Si/Si/SiC/C; (2) reaction/infiltration with calcium aluminum silicate; (3) ion exchange mechanism to form calcium hexaluminate (a refractory cement); and (4) oxide frit brazing with cordierite

  20. Amidated joining peptide in the human pituitary, gut, adrenal gland and bronchial carcinoids. Immunocytochemical and immunochemical evidence

    DEFF Research Database (Denmark)

    Bjartell, A; Fenger, M; Ekman, R;

    1990-01-01

    The distribution of the proopiomelanocortin-derivated amidated joining peptide (JP-N) was examined in the human pituitary gland, adrenal gland, gut and in three bronchial carcinoids. Double immunostaining showed coexistence of immunoreactive JP-N and other proopiomelanocortin derivatives, e......-N was costored with somatostatin in endocrine cells. Using radioimmunoassay, JP-N was found in higher concentrations than ACTH and alpha-MSH in the gut but not in the adrenal gland. Gel chromatography of gastric antrum and adrenal gland extracts showed three and two dominating components of immunoreactive JP......-N, respectively, but under reduced conditions most of the immunoreactive material appeared as of low molecular weight in both extracts. In conclusion, immunoreactive JP-N is a major product from the processing of proopiomelanocortin in human extrapituitary tissues. The molecular forms of immunoreactive JP...

  1. Microwave joining of SiC

    Energy Technology Data Exchange (ETDEWEB)

    Silberglitt, R.; Ahmad, I.; Tian, Y.L. [FM Technologies, Inc., Fairfax, VA (United States)] [and others

    1997-04-01

    The purpose of this work is to optimize the properties of SiC-SiC joints made using microwave energy. The current focus is on identification of the most effective joining methods for scale-up to large tube assemblies, including joining using SiC produced in situ from chemical precursors. During FY 1996, a new microwave applicator was designed, fabricated and tested that provides the capability for vacuum baking of the specimens and insulation and for processing under inert environment. This applicator was used to join continuous fiber-reinforced (CFCC) SiC/SiC composites using a polymer precursor to form a SiC interlayer in situ.

  2. The chemical bond structure and dynamics

    CERN Document Server

    Zewail, Ahmed

    1992-01-01

    This inspired book by some of the most influential scientists of our time--including six Nobel laureates--chronicles our emerging understanding of the chemical bond through the last nine decades and into the future. From Pauling's early structural work using x-ray and electron diffraction to Zewail's femtosecond lasers that probe molecular dynamics in real time; from Crick's molecular biology to Rich's molecular recognition, this book explores a rich tradition of scientific heritage and accomplishment. The perspectives given by Pauling, Perutz, Rich, Crick, Porter, Polanyi, Herschbach, Zewail,

  3. Joining NanoSIMS and STXM/NEXAFS to visualize soil biotic and abiotic processes at the nano-scale

    Science.gov (United States)

    Pett-Ridge, J.; Keiluweit, M.; Bougoure, J.; Weber, P. K.; Kleber, M.; Nico, P.

    2012-04-01

    Understanding the fate and residence time of organic matter in soils is important to natural resource management, including strategies to mitigate climate change. The time scales of carbon cycling, the relative importance of biotic and abiotic processes in organic matter stabilization in soils, and spatial factors in these processes are all critical characteristics that currently cannot be addressed by any single analytical approach. Here we demonstrate how many of these concerns can be approached by a combination of high-resolution secondary ion mass spectroscopy (NanoSIMS) and Scanning Transmission X-ray Microscopy (STXM) coupled with Near Edge X-ray Absorption Fine Structure spectroscopy (NEXAFS). When used in concert, these analytical techniques have the capacity to yield quantitative, in situ information on the source, molecular class, and elemental quantity of organic matter. We: (i) discuss the rationale for the joined application of the two procedures, (ii) provide examples for the their combined application, (iii) point out some of the methodological caveats that warrant consideration, and (iv) provide some directions for future developmental efforts. To illustrate the synergies of this combined approach, we examined organic-mineral associations in samples from both an artificial well-defined mixture and an unconstrained natural soil decomposition experiment. Case 1 demonstrates how the joined techniques help to determine modes of interaction between 13C- and 15N-labeled microorganisms and a defined mineral phase;, in case 2 we examine the incorporation of a 15N label into mineral organic associations 12 years after application to a forest soil. This unique analytical combination, the simultaneous application of STXM/NEXAFS and NanoSIMS imaging, has the potential to contribute a mechanistic understanding of sorption, occlusion, and decomposition processes that operate at fine spatial scales in natural environments.

  4. The Laplace transform of the cut-and-join equation of Mari\\~no-Vafa formula and its applications

    CERN Document Server

    Zhu, Shengmao

    2010-01-01

    By the same method introduced in [9], we calculate the Laplace transform of the celebrated cut-and-join equation of Mari\\~no-Vafa formula discovered by C. Liu, K. Liu and J. Zhou [17]. Then, we study the applications of the polynomial identity (1) obtained in theorem 1.1 of this paper. We show the proof Bouchard-Mari\\~no conjecture for C^3 which was given by L. Chen [5] Firstly. Subsequently, we will present how to obtain series Hodge integral identities from this polynomial identity (1). In particular, the main result in [9] is one of special case in such series of Hodge integral identities. At last, we give a explicit formula for the computation of Hodge integral _{g} where b_L = (b_1,..,b_l).

  5. Theoretical study for Bond between Reinforcement steel and Concrete

    Directory of Open Access Journals (Sweden)

    usama mostafa mahran

    2013-04-01

    Full Text Available The behavior and load carrying behavior of reinforced concrete structures is influence by the interaction between the concrete and reinforcement. The stress transfer between reinforcement and concrete in the longitudinal direction of the bars is called bond. An essential feature of reinforced concrete is the bond between steel and concrete. Anchorage of reinforcement depends on the bond between steel and concrete, crack width and crack spacing are mainly governed by it. So, stiffness, deformation and dynamic behavior are influenced by it, and in reverse loading damping and energy dissipation is a function of bond. This is one of the reasons why bond has been, and still is, a topic of fundamental and applied research. Bond stress is the equivalent unit shear stress acting in parallel to the reinforcing bar on the interface between reinforcing steel bar and concrete. Due to the transfer of forces through bond stress, between the reinforcing rebar and concrete, the force in the reinforcing bar changes along its length. Because bond stress is thought of as stress per unit area of bar surface, it is related to the rate of change of steel stress. Consequently, to have bond stress it is necessary to have a changing steel stress. In cases of high stress at the contact interface, near cracks or end anchorages, the bond stresses are related to relative displacements between concrete and steel. These relative displacements, which are caused by different average strains in the concrete and the steel, are usually called bond-slip (t-d.

  6. PAXX and XLF DNA repair factors are functionally redundant in joining DNA breaks in a G1-arrested progenitor B-cell line.

    Science.gov (United States)

    Kumar, Vipul; Alt, Frederick W; Frock, Richard L

    2016-09-20

    Classical nonhomologous end joining (C-NHEJ) is a major mammalian DNA double-strand break (DSB) repair pathway. Core C-NHEJ factors, such as XRCC4, are required for joining DSB intermediates of the G1 phase-specific V(D)J recombination reaction in progenitor lymphocytes. Core factors also contribute to joining DSBs in cycling mature B-lineage cells, including DSBs generated during antibody class switch recombination (CSR) and DSBs generated by ionizing radiation. The XRCC4-like-factor (XLF) C-NHEJ protein is dispensable for V(D)J recombination in normal cells, but because of functional redundancy, it is absolutely required for this process in cells deficient for the ataxia telangiectasia-mutated (ATM) DSB response factor. The recently identified paralogue of XRCC4 and XLF (PAXX) factor has homology to these two proteins and variably contributes to ionizing radiation-induced DSB repair in human and chicken cells. We now report that PAXX is dispensable for joining V(D)J recombination DSBs in G1-arrested mouse pro-B-cell lines, dispensable for joining CSR-associated DSBs in a cycling mouse B-cell line, and dispensable for normal ionizing radiation resistance in both G1-arrested and cycling pro-B lines. However, we find that combined deficiency for PAXX and XLF in G1-arrested pro-B lines abrogates DSB joining during V(D)J recombination and sensitizes the cells to ionizing radiation exposure. Thus, PAXX provides core C-NHEJ factor-associated functions in the absence of XLF and vice versa in G1-arrested pro-B-cell lines. Finally, we also find that PAXX deficiency has no impact on V(D)J recombination DSB joining in ATM-deficient pro-B lines. We discuss implications of these findings with respect to potential PAXX and XLF functions in C-NHEJ. PMID:27601633

  7. Carbonate clumped isotope bond reordering and geospeedometry

    Science.gov (United States)

    Passey, Benjamin H.; Henkes, Gregory A.

    2012-10-01

    Carbonate clumped isotope thermometry is based on the preference of 13C and 18O to form bonds with each other. At elevated temperatures such bond ordering is susceptible to resetting by diffusion of C and O through the solid mineral lattice. This type of bond reordering has the potential to obscure primary paleoclimate information, but could also provide a basis for reconstructing shallow crustal temperatures and cooling rates. We determined Arrhenius parameters for solid-state reordering of C-O bonds in two different calcites through a series of laboratory heating experiments. We find that the calcites have different susceptibilities to solid-state reordering. Reaction progress follows a first order rate law in both calcites, but only after an initial period of non-first order reaction that we suggest relates to annealing of nonequilibrium defects when the calcites are first heated to experimental temperature. We show that the apparent equilibrium temperature equations (or "closure temperature" equations) for carbonate clumped isotope reordering are analogous Dodson's equations for first order loss of daughter isotopes. For each calcite, the sensitivity of apparent equilibrium temperature to cooling rate is sufficiently high for inference of cooling rates within a factor of ˜5 or better for cooling rates ranging from tens of degrees per day to a few degrees per million years. However, because the calcites have different susceptibilities to reordering, each calcite defines its own cooling rate-apparent equilibrium temperature relationship. The cooling rates of Carrara marble inferred from carbonate clumped isotope geospeedometry are 10-6-10-3 degrees per annum and are in broad agreement with rates inferred from thermochronometric methods. Cooling rates for 13C-depleted calcites from the late Neoproterozoic Doushantou cap carbonates in south China are on the order of 102-104 degrees per annum, consistent with rapid cooling following formation of these calcites by a

  8. Surface plasmon resonance assisted rapid laser joining of glass

    Energy Technology Data Exchange (ETDEWEB)

    Zolotovskaya, Svetlana A.; Tang, Guang; Abdolvand, Amin, E-mail: a.abdolvand@dundee.ac.uk [School of Engineering, Physics and Mathematics, University of Dundee, Dundee DD1 4HN (United Kingdom); Wang, Zengbo [School of Electronic Engineering, Bangor University, Bangor LL57 1UT (United Kingdom)

    2014-08-25

    Rapid and strong joining of clear glass to glass containing randomly distributed embedded spherical silver nanoparticles upon nanosecond pulsed laser irradiation (∼40 ns and repetition rate of 100 kHz) at 532 nm is demonstrated. The embedded silver nanoparticles were ∼30–40 nm in diameter, contained in a thin surface layer of ∼10 μm. A joint strength of 12.5 MPa was achieved for a laser fluence of only ∼0.13 J/cm{sup 2} and scanning speed of 10 mm/s. The bonding mechanism is discussed in terms of absorption of the laser energy by nanoparticles and the transfer of the accumulated localised heat to the surrounding glass leading to the local melting and formation of a strong bond. The presented technique is scalable and overcomes a number of serious challenges for a widespread adoption of laser-assisted rapid joining of glass substrates, enabling applications in the manufacture of microelectronic devices, sensors, micro-fluidic, and medical devices.

  9. Diffusion Bonding Beryllium to Reduced Activation Ferritic Martensitic Steel: Development of Processes and Techniques

    Science.gov (United States)

    Hunt, Ryan Matthew

    Only a few materials are suitable to act as armor layers against the thermal and particle loads produced by magnetically confined fusion. These candidates include beryllium, tungsten, and carbon fiber composites. The armor layers must be joined to the plasma facing components with high strength bonds that can withstand the thermal stresses resulting from differential thermal expansion. While specific joints have been developed for use in ITER (an experimental reactor in France), including beryllium to CuCrZr as well as tungsten to stainless steel interfaces, joints specific to commercially relevant fusion reactors are not as well established. Commercial first wall components will likely be constructed front Reduced Activation Ferritic Martensitic (RAFM) steel, which will need to be coating with one of the three candidate materials. Of the candidates, beryllium is particularly difficult to bond, because it reacts during bonding with most elements to form brittle intermetallic compounds. This brittleness is unacceptable, as it can lead to interface crack propagation and delamination of the armor layer. I have attempted to overcome the brittle behavior of beryllium bonds by developing a diffusion bonding process of beryllium to RAFM steel that achieves a higher degree of ductility. This process utilized two bonding aids to achieve a robust bond: a. copper interlayer to add ductility to the joint, and a titanium interlayer to prevent beryllium from forming unwanted Be-Cu intermetallics. In addition, I conducted a series of numerical simulations to predict the effect of these bonding aids on the residual stress in the interface. Lastly, I fabricated and characterized beryllium to ferritic steel diffusion bonds using various bonding parameters and bonding aids. Through the above research, I developed a process to diffusion bond beryllium to ferritic steel with a 150 M Pa tensile strength and 168 M Pa shear strength. This strength was achieved using a Hot Isostatic

  10. An investigation on microstructure evolution and mechanical properties during liquid state diffusion bonding of Al2024 to Ti–6Al–4V

    International Nuclear Information System (INIS)

    Joining mechanism of Ti/Al dissimilar alloys was studied during liquid state diffusion bonding process using Cu/Sn/Cu interlayer at 510 °C under vacuum of 7.5 × 10−5 Torr for various bonding times. The microstructure and compositional changes in the joint zone were analyzed by scanning electron microscopy equipped with energy dispersive spectroscopy and X-ray diffraction. Microhardness and shear strength tests were also applied to study the mechanical properties of the joints. It was found that with an increase in bonding time, the elements of interlayer diffused into the parent metals and formed various intermetallic compounds at the interface. Diffusion process led to the isothermal solidification and the bonding evolution in the joint zone. The results from mechanical tests showed that microhardness and shear strength values have a straight relation with bonding time so that the maximum shear strength of joint was obtained for a bond made with 60 min bonding time. - Highlights: • Liquid state diffusion bonding of Al2024 to Ti–6Al–4V was performed successfully. • Diffusion of the elements caused the formation of various intermetallics at the interface. • Microhardness and shear strength values have a straight relation with bonding time. • The maximum shear strength reached to 36 MPa in 60 min bonding time

  11. The comovement of US and German bond markets

    DEFF Research Database (Denmark)

    Engsted, Tom; Tanggaard, Carsten

    2007-01-01

    We use a vector-autoregression, with parameter estimates corrected for small-sample bias, to decompose US and German unexpected bond returns into three 'news' components: news about future inflation, news about future real interest rates, and news about future excess bond returns (term premia). We...... inflation will increase, there is a tendency that German inflation will also increase. This is regarded bad news for the bond market in both countries whereby bond prices are bid down leading to immediate negative return innovations and changing expectations of future excess bond returns. Thus, comovement...

  12. Advances in modeling and design of adhesively bonded systems

    CERN Document Server

    Kumar, S

    2013-01-01

    The book comprehensively charts a way for industry to employ adhesively bonded joints to make systems more efficient and cost-effective Adhesively bonded systems have found applications in a wide spectrum of industries (e.g., aerospace, electronics, construction, ship building, biomedical, etc.) for a variety of purposes. Emerging adhesive materials with improved mechanical properties have allowed adhesion strength approaching that of the bonded materials themselves. Due to advances in adhesive materials and the many potential merits that adhesive bonding offers, adhesive bonding has replac

  13. TDP2-dependent non-homologous end-joining protects against topoisomerase II-induced DNA breaks and genome instability in cells and in vivo.

    Directory of Open Access Journals (Sweden)

    Fernando Gómez-Herreros

    Full Text Available Anticancer topoisomerase "poisons" exploit the break-and-rejoining mechanism of topoisomerase II (TOP2 to generate TOP2-linked DNA double-strand breaks (DSBs. This characteristic underlies the clinical efficacy of TOP2 poisons, but is also implicated in chromosomal translocations and genome instability associated with secondary, treatment-related, haematological malignancy. Despite this relevance for cancer therapy, the mechanistic aspects governing repair of TOP2-induced DSBs and the physiological consequences that absent or aberrant repair can have are still poorly understood. To address these deficits, we employed cells and mice lacking tyrosyl DNA phosphodiesterase 2 (TDP2, an enzyme that hydrolyses 5'-phosphotyrosyl bonds at TOP2-associated DSBs, and studied their response to TOP2 poisons. Our results demonstrate that TDP2 functions in non-homologous end-joining (NHEJ and liberates DSB termini that are competent for ligation. Moreover, we show that the absence of TDP2 in cells impairs not only the capacity to repair TOP2-induced DSBs but also the accuracy of the process, thus compromising genome integrity. Most importantly, we find this TDP2-dependent NHEJ mechanism to be physiologically relevant, as Tdp2-deleted mice are sensitive to TOP2-induced damage, displaying marked lymphoid toxicity, severe intestinal damage, and increased genome instability in the bone marrow. Collectively, our data reveal TDP2-mediated error-free NHEJ as an efficient and accurate mechanism to repair TOP2-induced DSBs. Given the widespread use of TOP2 poisons in cancer chemotherapy, this raises the possibility of TDP2 being an important etiological factor in the response of tumours to this type of agent and in the development of treatment-related malignancy.

  14. SUPERPLASTICITY AND DIFFUSION BONDING OF IN718 SUPERALLOY

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The superplasticity and diffusion bonding of IN718 superalloy were studied in this article. The strain rate sensitivity index m was obtained at different temperatures and various initial strain rates using the tensile speed mutation method; m reached its maximum value 0.53 at an initial strain rate of 1 ×10-4s-1 at 1253K. The diffusion bonding parameters, including the bonding temperature T,pressure p, and time t, affected the mechanism of joints. When the bonded specimen with 25μm thick nickel foil interlayer was tensile at room temperature, the shear fracture of the joints with nickel foil interlayer took place at the IN718 part. Microstructure study was carried out with the bonded samples. The microstructure shows an excellent bonding at the interfaces. The optimum parameters for the diffusion bonding are: T= 1273-1323K, p = 20-30MPa, t = 45-60min.

  15. Evaluation of bond strength of different adhesive systems: Shear and Microtensile Bond Strength Test

    Science.gov (United States)

    GALLUSI, G.; GALEANO, P.; LIBONATI, A.; GIUCA, M.R.; CAMPANELLA, V.

    2010-01-01

    SUMMARY Objectives. Aim of this work is the in vitro bond strength evaluation of three bonding agents comparing the results of two kinds of test, Microtensile Bond Strength Test and a Shear Bond Strength Test. Bond strength tests have been used to test both direct and indirect restorative techniques to investigate if methods could give different results. Methods 72 human third molars have been collected and stored in physiological solution. Three kinds of test were conducted: 1- SB, 2- “Slice” preparation μTBS1, 3- “Stick” preparation μTBS2. We tested three different adhesive systems (Groups 1-2-3 n=24), two restorative techniques (subgroup A–B n=12). The tested adhesives were: Optibond FL (OFL) (Group 1), Optibond Solo Plus (OSP) (Group 2), Optibond Solo Plus Self-Etch (OSSE) (Group 3). For all tests was used a universal load machine Instron Machine. Results. Best values were found for Optibond FL with mean values of 45–50 MPa. Optibond Solo Plus resulted in values very similar and in some cases almost identical to FL. Optibond Solo Self Etch showed poorer adhesion in both direct and indirect restorative techniques. The parametric and non parametric statistical variance analysis pointed out the absence of significant differences between OFL and OSP, and demonstrated a significant difference for OSSE adhesive. Significance. The results confirm that a total etch two-step adhesive is the best compromise between easiness and effectiveness. PMID:23285371

  16. Development of fricriveting as a new joining technique for polymer and lightweight alloys; Entwicklung des Reibnietens als neues Fuegeverfahren fuer Kunststoff und Leichtbaulegierungen

    Energy Technology Data Exchange (ETDEWEB)

    Amancio-Filho, S.T.; Santos, J.F. dos [GKSS Forschungszentrum GmbH, Institut fuer Werkstoffforschung, Werkstoffmechanik, Geesthacht (Germany)

    2008-11-15

    The increasing demand on environmental consciousness, cost savings and high performance end products has been guiding scientists and engineers to a constant development of new materials and technologies. This class of lightweight structures are specially used in industrial fields such as transportation and modern civil engineering. Currently available joining methods for polymer-metal structures (adhesive bonding and mechanical fastening) are usually application-specific, presenting high operational costs, limited mechanical performance or are not environmental friendly. 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 one or more thermoplastic base plates. The high rotation speed and pressure increase friction and heat is generated. When the preset time is achieved the temperature highly increases and the rivet tip plasticizes. At this point rotation is decelerated and the axial pressure increased, so the plasticized rivet tip becomes deformed; 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 and mechanisms of FricRiveting. Sound friction riveted point-on-plate and single-rivet overlap joints with elevated joint efficiencies in terms of base materials strength were obtained (tensile joint efficiencies of about 97 % of the rivet strength and shear joint efficiencies of about 70 % of the polymer strength) through tensile and lap shear testing at room temperature. Finally, the microstructural changes and properties were described for this case-study joint. The feasibility of FricRiveting was demonstrated in this work by the presented

  17. Comparison of shear bond strength between unfilled resin to dry enamel and dentin bonding to moist and dry enamel

    Directory of Open Access Journals (Sweden)

    Yasini E.

    2005-05-01

    Full Text Available Statement of Problem: The use of dentine bondings on enamel and dentin in total etch protocols has recently become popular. Unfilled resin is hydrophobic and dentin bonding is hydrophilic in nature. This chemical difference could be effective in enamel bonding process. Purpose: The aim of this study was to compare the shear bond strength of unfilled resin to dry enamel and dentin bonding to dry and moist enamel. Materials and Methods: In this experimental study, a total of 30 incisor teeth were used. The specimens were randomly assigned to three groups of 10. 37% phosphoric acid etchant was applied to the enamel surfaces in each group for 15 seconds, rinsed with water for 20 seconds and dried for 20 seconds with compressed air in groups one and two. After conditioning, group 1 received unfilled resin (Margin Bond, Colten and group 2 received dentin bonding (Single Bond, 3M and in group 3 after conditioning and rinsing with water, a layer of dentin bonding (Single Bond was applied on wet enamel. The enamel and dentin bonding were light cured for 20 seconds. A ring mold 3.5 mm in diameter and 2 mm height was placed over the specimens to receive the composite filling material (Z100, 3M. The composite was cured for 40 seconds. The specimens were thermocycled and shear bond strengths were determined using an Instron Universal Testing Machine. The findings were analyzed by ANOVA One-Way and Tukey HSD tests. Results: Shear bond strength of dentin bonding to dry enamel was significantly less than unfilled resin to dry enamel (P<0.05. There was no significant difference between the bond strength of dentin bonding to moist and dry enamel. In addition bond strength of dentin bonding to wet enamel was not significantly different from unfilled resin to dry enamel. Conclusion: Based on the findings of this study, it is suggested that enamel surface should remain slightly moist after etching before bonding with single bond but when using unfilled resin, the

  18. Optimization of Laser Transmission Joining Process Parameters on Joint Strength of PET and 316 L Stainless Steel Joint Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Shashi Prakash Dwivedi

    2014-01-01

    Full Text Available The objective of the present work is to study the effects of laser power, joining speed, and stand-off distance on the joint strength of PET and 316 L stainless steel joint. The process parameters were optimized using response methodology for achieving good joint strength. The central composite design (CCD has been utilized to plan the experiments and response surface methodology (RSM is employed to develop mathematical model between laser transmission joining parameters and desired response (joint strength. From the ANOVA (analysis of variance, it was concluded that laser power is contributing more and it is followed by joining speed and stand-off distance. In the range of process parameters, the result shows that laser power increases and joint strength increases. Whereas joining speed increases, joint strength increases. The joint strength increases with the increase of the stand-off distance until it reaches the center value; the joint strength then starts to decrease with the increase of stand-off distance beyond the center limit. Optimum values of laser power, joining speed, and stand-off distance were found to be 18 watt, 100 mm/min, and 2 mm to get the maximum joint strength (predicted: 88.48 MPa. There was approximately 3.37% error in the experimental and modeled results of joint strength.

  19. Joining porous components to solid metal structures

    Science.gov (United States)

    Fortini, A.; Tulisiak, G.

    1972-01-01

    Process for joining porous metal material to solid metal structure without cracking or blockage of porous component is described. Procedures of electron beam welding and electroforming are discussed. Illustration of microstructure resulting from process is included.

  20. Comparison between vitrified bond and resin bond diamond grinding wheel in grinding PDC

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiaofu; Zhang Hongxia; Lu Anxian; Mark J. Jackson

    2008-01-01

    In this research, the advantages and disadvantages of the cylindrical grinding process of Polycrystalline Diamond Compacts (short for PDC) with vitrified and resin bond diamond grinding wheel are compared. The research results show that the vitrified bond diamond grinding wheels, which use Ti-coated diamond grains as abrasive and glass ceramic as bond, have many advantages in grinding PDC . Compared with resin diamond grinding wheel,vitrified bond wheels lead to 35% grinding cost reduced, 40% grinding time of each PDC saved, and the size precision of PDC improved (from ±0.03mm to ±0.01mm). When grinding feed is <0.10 mm, the grinding ratio increases with increased grinding feed. However, when the grinding feed exceeds 0.10 mm, the grinding radio decreases rapidly with the increasing of grinding feed. The disadvantage of this kind of grinding wheel is that the brightness of the ground PDC cylinder is not as shining as that processed by resin bond diamond grinding wheel.

  1. Spain to Join ESO

    Science.gov (United States)

    2006-02-01

    /infrared astronomical observing site in Europe and site of the Spanish 10m GranTeCan telescope now nearing completion. With the high quality of Spanish astronomical research as well as the technological competence of Spanish industry, it is only fitting that Spain should join ESO, world-leader in ground-based astronomy. Through ESO Spain will enjoy full access both to all of ESO's current facilities and to unrestricted participation in the great projects that ESO is planning for the future. Spain is already an active partner of the Atacama Large Millimeter Array (ALMA), whose construction and operations are led on behalf of Europe by ESO. ESO's Council approved the admission of Spain at its 107th meeting held in Garching on 7 and 8 December 2005. High resolution images and their captions are available on this page.

  2. Simulation of mechanical joining for automotive applications

    OpenAIRE

    Gårdstam, Johannes

    2006-01-01

    Regarding the use of material, modern lightweight car bodies are becoming more and more complex than previous constructions. The materials nowadays are used for a more specific field of application and more high strength steels are used and also other materials like aluminium, stainless steel, reinforced polymers are used more frequent. The joining of these materials often requires new or modified joining processes. The aim with this thesis is concerned with the development of simulation mode...

  3. Laser Assisted Joining of Hybrid Polyamide-aluminum Structures

    Science.gov (United States)

    Lamberti, Christian; Solchenbach, Tobias; Plapper, Peter; Possart, Wulff

    The demand for hybrid polymer-metal structures is continuously growing due to their great potential in automotive, aerospace and packaging applications. The expected capabilities are highly diverse and include functional, chemical and mechanical as well as economical and ecological aspects. A novel laser beam joining process for hybrid polyamide-aluminum structures is reported. The spatial and temporal heat input is optimized for optimal bonding quality. At the interface it was proven that the polyamide was not decomposed as a result of excessive thermal stress. It was shown that laser or electro-chemical surface pre-treatment of the aluminum substrate has a distinctive effect on the shear strength of the joint. However, the bond quality does not correspond to a change of surface roughness. Therefore, mechanical interlocking in direct relation to surface topology of the pre-treated substrate is not the principal cause for the bonding phenomenon. Chemical analysis in terms of IR-spectroscopy has shown a physicochemical interaction based on hydrogen bonds.

  4. A study on the Joining Properties of Bi-2212 High-Tc Superconducting Tube and Indium Solder

    International Nuclear Information System (INIS)

    As a material for SFCL(Superconducting Fault Current Limiter), BSCCO tube with metal stabilizer is a promising candidate, assuring the stability and large power capacity, For the application, the proper soldering technique, which overcome the difficulties of the joining between BSCCO and metal stabilizer, is required. In this study, after soldering In-Bi solder and In-Sn solder with BSCCO superconductor, welding properties between BSCCO and solders were investigated. Because ceramic materials is difficult to weld, Ag electro-plating on BSCCO 2212 is used for intermetallic layer. To find out the best welding condition for superconductor, soldering is tested in the maximum temperature from 155 degrees C to 165 degrees C in the reflow oven. By investigating the composition and thickness of IMC (lntermetallic Compound) created in the reaction of Ag with solder, we analyzed the welding properties of High-Tc superconductor from a micro point of view.

  5. Theoretical study of the interplay between lithium bond and hydrogen bond in complexes involved with HLi and HCN.

    Science.gov (United States)

    Li, Qingzhong; Hu, Ting; An, Xiulin; Li, Wenzuo; Cheng, Jianbo; Gong, Baoan; Sun, Jiazhong

    2009-12-21

    The lithium- and hydrogen-bonded complex of HLi-NCH-NCH is studied with ab initio calculations. The optimized structure, vibrational frequencies, and binding energy are calculated at the MP2 level with 6-311++G(2d,2p) basis set. The interplay between lithium bonding and hydrogen bonding in the complex is investigated with these properties. The effect of lithium bonding on the properties of hydrogen bonding is larger than that of hydrogen bonding on the properties of lithium bonding. In the trimer, the binding energies are increased by about 19% and 61% for the lithium and hydrogen bonds, respectively. A big cooperative energy (-5.50 kcal mol(-1)) is observed in the complex. Both the charge transfer and induction effect due to the electrostatic interaction are responsible for the cooperativity in the trimer. The effect of HCN chain length on the lithium bonding has been considered. The natural bond orbital and atoms in molecules analyses indicate that the electrostatic force plays a main role in the lithium bonding. A many-body interaction analysis has also been performed for HLi-(NCH)(N) (N=2-5) systems.

  6. COMPARATIVE EVALUATION OF THE BONDING EFFICACY OF SIXTH, SEVENTH AND EIGHTH GENERATION BONDING AGENTS: AN IN VITRO STUDY

    OpenAIRE

    Paul Joseph; Chakravarthy Yadav; Kumar Satheesh; Raju Rahna

    2013-01-01

    The aim of the study was to compare In-vitro the micro tensile bond strength of sixth generation (Clearfil SE Bond, Kuraray, Japan), seventh generation (Adper Easy One, 3 M ESPE, Germany) and eighth generation ((Futurabond DC, Voco, Germany) dentin bonding agents. Twenty freshly extracted caries free, unrestored human molars were selected. The occlusal surfaces were ground flat; divided into four groups of five each according to the bonding agent applied and covered with composite resin (10 m...

  7. Electric field effects on one-bond indirect spin-spin coupling constants and possible biomolecular perspectives.

    Science.gov (United States)

    Sahakyan, Aleksandr B; Shahkhatuni, Aleksan G; Shahkhatuni, Astghik A; Panosyan, Henry A

    2008-04-24

    Electric field (EF) induced changes of one-bond indirect spin-spin coupling constants are investigated on a wide range of molecules including peptide models. EFs were both externally applied and internally calculated without external EF application by the hybrid density functional theory method. Reliable agreement with experimental data has been obtained for calculated one-bond J-couplings. The role of the EF sign and direction, internal and induced components, hydrogen bonding, internuclear distance and hyperconjugative interactions on the one-bond J-coupling vs EF interconnection is analyzed. A linear dependence of 1J on EF projection along the bond is obtained, if the bound atoms possess different enough electron densities and an EF determined by the electronic polarization exists along the bond. Accentuating the 1JNH couplings as possible EF sensitive parameters, a systematic study is done in two sets of molecules with a large variation of the native internal EF value. The most EF affected component of the 1JNH coupling constant is the spin-dipole term of Ramsey's formulation; however, in the total J-coupling formation, the EF influence on the Fermi contact term is the most significant. The induced EF projection along the bond is 6.7 times weaker in magnitude than the simulated external uniform field. The absolute EF dependence of the one-bond J-coupling involves only the internal field, which is the sum of the induced field (if the external field exists) and the internuclear field determined by the native polarization. That linear and universal dependence joins the corresponding couplings in a diverse set of molecules under various electrostatic conditions. Many types of the one-bond J-couplings can be potentially measured in biomolecules, and the study of their relation with the electrostatic properties at the corresponding sites opens a new avenue to the full exploitation of the NMR measurable parameters with novel and exciting applications. PMID:18363392

  8. Recrafting the Neighbor-Joining Method

    DEFF Research Database (Denmark)

    Mailund; Brodal, Gerth Stølting; Fagerberg, Rolf;

    2006-01-01

    Background: The neighbor-joining method by Saitou and Nei is a widely used method for constructing phylogenetic trees. The formulation of the method gives rise to a canonical Θ(n3) algorithm upon which all existing implementations are based. Methods: In this paper we present techniques for speeding...... up the canonical neighbor-joining method. Our algorithms construct the same phylogenetic trees as the canonical neighbor-joining method. The best-case running time of our algorithms are O(n2) but the worst-case remains O(n3). We empirically evaluate the performance of our algoritms on distance...... neighbor-joining method. Conclusions: The experiments show that our algorithms also yield a significant speed-up, already for medium sized instances....

  9. Reactive diffusion bonding of SiCp/Al composites by insert layers of mixed Al-Si and Al-Si-SiC powders

    Institute of Scientific and Technical Information of China (English)

    Jihua Huang; Yueling Dong; Yun Wan; Jiangang Zhang; Hua Zhang

    2005-01-01

    Mixed Al-Si and Al-Si-SiC powders were employed as insert layers to reactive diffusion bond SiCp/6063 MMC (metal matrix composites). The results show that SiCp/6063 MMC joints bonded by the insert layer of the mixed Al-Si powder have a dense joining layer with a typical hypoeutectic microstructure. Using the mixed Al-Si-SiC powder as the insert layer, SiCp/6063 MMC can be reactive diffusion bonded by a composite joint. Because of the SiC segregation, however, there are a number of porous zones in the joining layer, which results in the bad shear strength of the joints reactive diffusion bonded by the insert layer of the mixed Al-SiSiC powder, even lower than that of the joints reactive diffusion bonded by the insert layer of the mixed Al-Si powder. Ti and Mg added in the insert layers obviously improve the strength of the joints reactive diffusion bonded by the insert layer of the mixed AlSi-SiC powder, especially, Mg has a more obvious effect.

  10. The bond length and bond energy of gaseous CrW.

    Science.gov (United States)

    Matthew, Daniel J; Oh, Sang Hoon; Sevy, Andrew; Morse, Michael D

    2016-06-01

    Supersonically cooled CrW was studied using resonant two-photon ionization spectroscopy. The vibronically resolved spectrum was recorded over the region 21 100 to 23 400 cm(-1), showing a very large number of bands. Seventeen of these bands, across three different isotopologues, were rotationally resolved and analyzed. All were found to arise from the ground (1)Σ(+) state of the molecule and to terminate on states with Ω' = 0. The average r0 bond length across the three isotopic forms was determined to be 1.8814(4) Å. A predissociation threshold was observed in this dense manifold of vibronic states at 23 127(10) cm(-1), indicating a bond dissociation energy of D0(CrW) = 2.867(1) eV. Using the multiple bonding radius determined for atomic Cr in previous work, the multiple bonding radius for tungsten was calculated to be 1.037 Å. Comparisons are made between CrW and the previously investigated group 6 diatomic metals, Cr2, CrMo, and Mo2, and to previous computational studies of this molecule. It is also found that the accurately known bond dissociation energies of group 5/6 metal diatomics Cr2, V2, CrW, NbCr, VNb, Mo2, and Nb2 display a qualitative linear dependence on the sum of the d-orbital radial expectation values, r; this relationship allows the bond dissociation energies of other molecules of this type to be estimated. PMID:27276956

  11. Thioamides: versatile bonds to induce directional and cooperative hydrogen bonding in supramolecular polymers.

    Science.gov (United States)

    Mes, Tristan; Cantekin, Seda; Balkenende, Dirk W R; Frissen, Martijn M M; Gillissen, Martijn A J; De Waal, Bas F M; Voets, Ilja K; Meijer, E W; Palmans, Anja R A

    2013-06-24

    The amide bond is a versatile functional group and its directional hydrogen-bonding capabilities are widely applied in, for example, supramolecular chemistry. The potential of the thioamide bond, in contrast, is virtually unexplored as a structuring moiety in hydrogen-bonding-based self-assembling systems. We report herein the synthesis and characterisation of a new self-assembling motif comprising thioamides to induce directional hydrogen bonding. N,N',N''-Trialkylbenzene-1,3,5-tris(carbothioamide)s (thioBTAs) with either achiral or chiral side-chains have been readily obtained by treating their amide-based precursors with P2S5. The thioBTAs showed thermotropic liquid crystalline behaviour and a columnar mesophase was assigned. IR spectroscopy revealed that strong, three-fold, intermolecular hydrogen-bonding interactions stabilise the columnar structures. In apolar alkane solutions, thioBTAs self-assemble into one-dimensional, helical supramolecular polymers stabilised by three-fold hydrogen bonding. Concentration- and temperature-dependent self-assembly studies performed by using a combination of UV and CD spectroscopy demonstrated a cooperative supramolecular polymerisation mechanism and a strong amplification of supramolecular chirality. The high dipole moment of the thioamide bond in combination with the anisotropic shape of the resulting cylindrical aggregate gives rise to sufficiently strong depolarised light scattering to enable depolarised dynamic light scattering (DDLS) experiments in dilute alkane solution. The rotational and translational diffusion coefficients, D(trans) and D(rot), were obtained from the DDLS measurements, and the average length, L, and diameter, d, of the thioBTA aggregates were derived (L = 490 nm and d = 3.6 nm). These measured values are in good agreement with the value L(w) = 755 nm obtained from fitting the temperature-dependent CD data by using a recently developed equilibrium model. This experimental verification

  12. Bonding, structure and solid-state chemistry

    CERN Document Server

    Ladd, Mark

    2016-01-01

    This book is aimed at undergraduate students in both chemistry and those degree subjects in which chemistry forms a significant part. It does not reflect any particular academic year, and so finds a place during the normal span of degree studies in the physical sciences. An A-level standard in science and mathematics is presumed; additional mathematical treatments are discussed in Appendices. An introductory first chapter leads into the main subject matter, which is treated through four chapters in terms of the principle bonding forces of cohesion in the solid state; a further chapter discusses nanosize materials. Important applications of the study topics are interspersed at appropriate points within the text. Each chapter is provided with a set of problems of varying degrees of difficulty, so as to assist the reader in gaining a facility with the subject matter and its applications. The problems are supplemented by detailed tutorial solutions, some of which present additional relevant material that indicate...

  13. Hydrogen bonds in concreto and in computro

    Science.gov (United States)

    Stouten, Pieter F. W.; Kroon, Jan

    1988-07-01

    Molecular dynamics simulations of liquid water and liquid methanol have been carried out. For both liquids an effective pair potential was used. The models were fitted to the heat of vaporization, pressure and various radial distribution functions resulting from diffraction experiments on liquids. In both simulations 216 molecules were put in a cubic periodical ☐. The system was loosely coupled to a temperature bath and to a pressure bath. Following an initial equilibration period relevant data were sampled during 15 ps. The distributions of oxygen—oxygen distances in hydrogen bonds obtained from the two simulations are essentially the same. The distribution obtained from crystal data is somewhat different: the maximum has about the same position, but the curve is much narrower, which can be expected merely from the fact that diffraction experiments only supply average atomic positions and hence average interatomic distances. When thermal motion is taken into account a closer likeness is observed.

  14. Speeding Up Neighbour-Joining Tree Construction

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Fagerberg, Rolf; Mailund, Thomas;

    A widely used method for constructing phylogenetic trees is the neighbour-joining method of Saitou and Nei. We develope heuristics for speeding up the neighbour-joining method which generate the same phylogenetic trees as the original method. All heuristics are based on using a quad-tree to guide...... the search for the next pair of nodes to join, but di#er in the information stored in quad-tree nodes, the way the search is performed, and in the way the quad-tree is updated after a join. We empirically evaluate the performance of the heuristics on distance matrices obtained from the Pfam collection...... of alignments, and compare the running time with that of the QuickTree tool, a well-known and widely used implementation of the standard neighbour-joining method. The results show that the presented heuristics can give a significant speed-up over the standard neighbour-joining method, already for medium sized...

  15. Accounting for the differences in the structures and relative energies of the highly homoatomic np pi-np pi (n > or = 3)-bonded S2I4 2+, the Se-I pi-bonded Se2I4 2+, and their higher-energy isomers by AIM, MO, NBO, and VB methodologies.

    Science.gov (United States)

    Brownridge, Scott; Crawford, Margaret-Jane; Du, Hongbin; Harcourt, Richard D; Knapp, Carsten; Laitinen, Risto S; Passmore, Jack; Rautiainen, J Mikko; Suontamo, Reijo J; Valkonen, Jussi

    2007-02-01

    The bonding in the highly homoatomic np pi-np pi (n > or = 3)-bonded S2I42+ (three sigma + two pi bonds), the Se-I pi-bonded Se2I42+ (four sigma + one pi bonds), and their higher-energy isomers have been studied using modern DFT and ab initio calculations and theoretical analysis methods: atoms in molecules (AIM), molecular orbital (MO), natural bond orbital (NBO), and valence bond (VB) analyses, giving their relative energies, theoretical bond orders, and atomic charges. The aim of this work was to seek theory-based answers to four main questions: (1) Are the previously proposed simple pi*-pi* bonding models valid for S2I42+ and Se2I42+? (2) What accounts for the difference in the structures of S2I42+ and Se2I42+? (3) Why are the classically bonded isolobal P2I4 and As2I4 structures not adopted? (4) Is the high experimentally observed S-S bond order supported by theoretical bond orders, and how does it relate to high bond orders between other heavier main group elements? The AIM analysis confirmed the high bond orders and established that the weak bonds observed in S2I42+ and Se2I42+ are real and the bonding in these cations is covalent in nature. The full MO analysis confirmed that S2I42+ contains three sigma and two pi bonds, that the positive charge is essentially equally distributed over all atoms, that the bonding between S2 and two I2+ units in S2I42+ is best described by two mutually perpendicular 4c2e pi*-pi* bonds, and that in Se2I42+, two SeI2+ moieties are joined by a 6c2e pi*-pi* bond, both in agreement with previously suggested models. The VB treatment provided a complementary approach to MO analysis and provided insight how the formation of the weak bonds affects the other bonds. The NBO analysis and the calculated AIM charges showed that the minimization of the electrostatic repulsion between EI2+ units (E = S, Se) and the delocalization of the positive charge are the main factors that explain why the nonclassical structures are favored for S2I42

  16. Accounting for the differences in the structures and relative energies of the highly homoatomic np pi-np pi (n > or = 3)-bonded S2I4 2+, the Se-I pi-bonded Se2I4 2+, and their higher-energy isomers by AIM, MO, NBO, and VB methodologies.

    Science.gov (United States)

    Brownridge, Scott; Crawford, Margaret-Jane; Du, Hongbin; Harcourt, Richard D; Knapp, Carsten; Laitinen, Risto S; Passmore, Jack; Rautiainen, J Mikko; Suontamo, Reijo J; Valkonen, Jussi

    2007-02-01

    The bonding in the highly homoatomic np pi-np pi (n > or = 3)-bonded S2I42+ (three sigma + two pi bonds), the Se-I pi-bonded Se2I42+ (four sigma + one pi bonds), and their higher-energy isomers have been studied using modern DFT and ab initio calculations and theoretical analysis methods: atoms in molecules (AIM), molecular orbital (MO), natural bond orbital (NBO), and valence bond (VB) analyses, giving their relative energies, theoretical bond orders, and atomic charges. The aim of this work was to seek theory-based answers to four main questions: (1) Are the previously proposed simple pi*-pi* bonding models valid for S2I42+ and Se2I42+? (2) What accounts for the difference in the structures of S2I42+ and Se2I42+? (3) Why are the classically bonded isolobal P2I4 and As2I4 structures not adopted? (4) Is the high experimentally observed S-S bond order supported by theoretical bond orders, and how does it relate to high bond orders between other heavier main group elements? The AIM analysis confirmed the high bond orders and established that the weak bonds observed in S2I42+ and Se2I42+ are real and the bonding in these cations is covalent in nature. The full MO analysis confirmed that S2I42+ contains three sigma and two pi bonds, that the positive charge is essentially equally distributed over all atoms, that the bonding between S2 and two I2+ units in S2I42+ is best described by two mutually perpendicular 4c2e pi*-pi* bonds, and that in Se2I42+, two SeI2+ moieties are joined by a 6c2e pi*-pi* bond, both in agreement with previously suggested models. The VB treatment provided a complementary approach to MO analysis and provided insight how the formation of the weak bonds affects the other bonds. The NBO analysis and the calculated AIM charges showed that the minimization of the electrostatic repulsion between EI2+ units (E = S, Se) and the delocalization of the positive charge are the main factors that explain why the nonclassical structures are favored for S2I42

  17. Expectations, Bond Yields and Monetary Policy

    DEFF Research Database (Denmark)

    Chun, Albert Lee

    2011-01-01

    Through explicitly incorporating analysts' forecasts as observable factors in a dynamic arbitrage-free model of the yield curve, this research proposes a framework for studying the impact of shifts in market sentiment on interest rates of all maturities. An empirical examination reveals that survey...... while accommodating output growth and monetary policy expectations. Forecasted GDP growth plays a significant role in explaining time variation in the market prices of risk. The sensitivity of long yields is linked to the persistence of expected inflation under the risk-neutral measure. Models...... of this type may provide traders and policymakers with a new set of tools for formally assessing the reaction of bond yields to shifts in market expectations...

  18. Change of gene structure and function by non-homologous end-joining, homologous recombination, and transposition of DNA.

    Directory of Open Access Journals (Sweden)

    Wolfgang Goettel

    2009-06-01

    Full Text Available An important objective in genome research is to relate genome structure to gene function. Sequence comparisons among orthologous and paralogous genes and their allelic variants can reveal sequences of functional significance. Here, we describe a 379-kb region on chromosome 1 of maize that enables us to reconstruct chromosome breakage, transposition, non-homologous end-joining, and homologous recombination events. Such a high-density composition of various mechanisms in a small chromosomal interval exemplifies the evolution of gene regulation and allelic diversity in general. It also illustrates the evolutionary pace of changes in plants, where many of the above mechanisms are of somatic origin. In contrast to animals, somatic alterations can easily be transmitted through meiosis because the germline in plants is contiguous to somatic tissue, permitting the recovery of such chromosomal rearrangements. The analyzed region contains the P1-wr allele, a variant of the genetically well-defined p1 gene, which encodes a Myb-like transcriptional activator in maize. The P1-wr allele consists of eleven nearly perfect P1-wr 12-kb repeats that are arranged in a tandem head-to-tail array. Although a technical challenge to sequence such a structure by shotgun sequencing, we overcame this problem by subcloning each repeat and ordering them based on nucleotide variations. These polymorphisms were also critical for recombination and expression analysis in presence and absence of the trans-acting epigenetic factor Ufo1. Interestingly, chimeras of the p1 and p2 genes, p2/p1 and p1/p2, are framing the P1-wr cluster. Reconstruction of sequence amplification steps at the p locus showed the evolution from a single Myb-homolog to the multi-gene P1-wr cluster. It also demonstrates how non-homologous end-joining can create novel gene fusions. Comparisons to orthologous regions in sorghum and rice also indicate a greater instability of the maize genome, probably due to

  19. 27 CFR 19.241 - Operations bond-distilled spirits plant and adjacent bonded wine cellar.

    Science.gov (United States)

    2010-04-01

    ... wine cellar. (a) General. A wine cellar under the provisions of 27 CFR part 24 shall be treated as... spirits plant and adjacent bonded wine cellar. 19.241 Section 19.241 Alcohol, Tobacco Products and... subpart G for the production of distilled spirits; and (2) Such wine cellar and distilled spirits...

  20. Bond Properties and Experimental Methods of Textile Reinforced Concrete

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Textile reinforced concrete(TRC, for short) allows the low size production and offers a high effectiveness of the reinforcement by using continuous roving instead of short-chopped fibers. However, whether textiles can cooperate with concrete very well depends on the bond between them. In this paper, the bonding mechanism that the stress was transferred from fine concrete to textile was analyzed, and the influences of the initial bond length of textile, the surface treatment of textile, the strength and workability of concrete as well as the level of prestressing force on bond behavior were investigated on the basis of pull-out tests. The results reveal that with initial bond length increasing, the maximum pull force increases, and increasing concrete strength and improving workability of concrete matrix, epoxy resin impregnating and sand covering of textile as well as prestressing textile can obviously increase the bond strength between the textile and concrete.

  1. Anion–arene adducts: C–H hydrogen bonding, anion– interaction, and carbon bonding motifs

    OpenAIRE

    Hay, Benjamin P.; Bryantsev, Vyacheslav S.

    2008-01-01

    This article summarizes experimental and theoretical evidence for the existence of four distinct binding modes for complexes of anions with charge-neutral arenes. These include C–H hydrogen bonding and three motifs involving the arene– system—the noncovalent anion– interaction, weakly covalent interaction, and strongly covalent interaction.

  2. The Pricing and Efficiency of Australian Treasury Bond Futures

    Directory of Open Access Journals (Sweden)

    Alex Frino

    2014-06-01

    Full Text Available This paper examines the efficiency of the Treasury Bond futures market in Australia. We provide a comprehensive explanation of the method used to price, and evaluate efficiency of the 3 and 10 Year Australian Treasury Bond Futures contracts, against underlying bond baskets. Results indicate that the futures contracts exhibit minimal variation from their theoretical value. The average mispricing equates to 1.96 basis points for 3 Year and 1.19 basis points for 10 Year government bond futures contracts. However, during some periods (including the financial crisis of 2008, the bond futures contracts exhibit greater mispricing. Consistent with prior literature, we find a decreasing pattern of mispricing towards expiry, with the futures contract yields and average forward yields of the underlying bonds converging towards expiry. Further analysis reveals that volatility and time to expiry exhibit a significant positive relationship with the absolute level of mispricing.

  3. The Romanian Municipal Bond Market and the International Financial Crisis

    Directory of Open Access Journals (Sweden)

    VALENTINA VASILE

    2010-06-01

    Full Text Available In Romania, the bond market was set up later, comparatively to the equity market. This market is in a development process, but the international financial crisis has affected even the interest of investors in bonds. The secondary municipal bond market is not a very liquid market because these securities are bought from the primary market and held in portfolios by investors because these bonds have a low risk. The issue of these bonds is correlated with the financial independence and the level of decentralization of the local public authorities. The issuance of these bonds is correlated with financial independence and decentralization level specific to local public authorities. Under crisis conditions, the volatility of this market is more significant, the increasing deficits of local budgets decreasing the interest of the middle-class in investing in such financial instruments.

  4. Childhood exposure to violence and lifelong health: clinical intervention science and stress-biology research join forces.

    Science.gov (United States)

    Moffitt, Terrie E

    2013-11-01

    Many young people who are mistreated by an adult, victimized by bullies, criminally assaulted, or who witness domestic violence react to this violence exposure by developing behavioral, emotional, or learning problems. What is less well known is that adverse experiences like violence exposure can lead to hidden physical alterations inside a child's body, alterations that may have adverse effects on life-long health. We discuss why this is important for the field of developmental psychopathology and for society, and we recommend that stress-biology research and intervention science join forces to tackle the problem. We examine the evidence base in relation to stress-sensitive measures for the body (inflammatory reactions, telomere erosion, epigenetic methylation, and gene expression) and brain (mental disorders, neuroimaging, and neuropsychological testing). We also review promising interventions for families, couples, and children that have been designed to reduce the effects of childhood violence exposure. We invite intervention scientists and stress-biology researchers to collaborate in adding stress-biology measures to randomized clinical trials of interventions intended to reduce effects of violence exposure and other traumas on young people. PMID:24342859

  5. Selective-area laser deposition (SALD) Joining of silicon carbide with silicon carbide filler

    Science.gov (United States)

    Harrison, Shay Llewellyn

    Selective Area Laser Deposition (SALD) is a gas-phase, solid freeform fabrication (SFF) process that utilizes a laser-driven, pyrolytic gas reaction to form a desired solid product. This solid product only forms in the heated zone of the laser beam and thus can be selectively deposited by control of the laser position. SALD Joining employs the SALD method to accomplish 'welding' of ceramic structures together. The solid reaction product serves as a filler material to bond the two parts. The challenges involved with ceramic joining center around the lack of a liquid phase, little plastic deformation and diffusivity and poor surface wetting for many ceramic materials. Due to these properties, traditional metal welding procedures cannot be applied to ceramics. Most alternative ceramic welding techniques use some form of a metal addition to overcome these material limitations. However, the metal possesses a lower ultimate use temperature than the ceramic substrate and therefore it decreases the temperature range over which the joined part can be safely used. SALD Joining enjoys several advantages over these ceramic welding procedures. The solid filler material chemistry can be tailored to match the type of ceramic substrate and therefore fabricate monolithic joints. The SALD filler material bonds directly to the substrate and the joined structure is made in a one step process, without any post-processing. The research documented in this dissertation focused on SALD Joining of silicon carbide structures with silicon carbide filler material. A historical progression of gas-phase SFF research and a literature review of the most prominent ceramic joining techniques are provided. A variety of SiC substrates were examined, as were various conditions of gas precursor pressures and mixtures, laser beam scan speed and joint configuration. The SALD material was characterized for composition and structure by x-ray diffraction, transmission electron microscopy and nuclear magnetic

  6. Interfiber bonding and fiber segment activation in paper

    Directory of Open Access Journals (Sweden)

    Hannu Paulapuro

    2007-01-01

    Full Text Available Bonding and activation in paper were studied with the help of laboratory test sheets and common paper strength tests. Different papermaking furnishes and raw material treatments were used to examine the effects they have on bonding and activation. Furthermore, various boundary conditions during drying were included to single out the influence of bonding and activation on paper properties. It was found that bonding is clearly increased by beating of kraft pulp, starch addition, and thermomechanical pulp fines, whereas activation benefited most from beating and addition of reinforcement fibers to mechanical pulp based furnishes. Subjecting test sheets to increasing amounts of drying stress affected activation positively, and bonding negatively. The increase in activation did not seem to be dependent on the beating degree of chemical pulp fibers. Bonding, on the other hand, deteriorated more significantly in sheets made of extensively beaten kraft fibers, i.e. in sheets where the initial bonding potential was higher. Commonly used paper strength measurements provide dependable and accurate tools for assessing the effect of different variables on both bonding and activation. A short literature survey of bonding and activation is also provided.

  7. Why join the Staff Association

    CERN Multimedia

    Association du personnel

    2011-01-01

    Becoming a member of the Staff Association (SA) is above all a personal choice, showing that the joining person’s commitment and adherence to values such as solidarity, social cohesion, etc.In September, the SA launches a membership campaign to convince a maximum number to join, to inform, arouse interest and support. Posters, emails and individual contacts are part of the campaign programme, just like this editorial. As far as individual contacts are concerned, we ask you to give time and lend an ear to the delegates of your department in the Staff Council, who will approach you, in order to make an open and constructive discussion possible. Do not hesitate to ask questions and let them know your thoughts about the SA, as (constructive) criticism enables us to progress. The Staff Association and its role of collective representation The Staff Association, via its delegates, represents collectively all staff of the Organization before the Director-General and Member States. To do this, staff rep...

  8. Bank Debt Regulations Implications for Bank Capital and Bond Risk

    OpenAIRE

    Stig Helberg; Snorre Lindset

    2013-01-01

    We use a structural model of default risk to study how optimal bank capital and bond risk are influenced by deposit insurance, implicit guarantees, depositor preference, asset encumbrance, and bail-in resolution frameworks. We find that these features of bank financing, in addition to having an immediate impact on bond debt risk, also change optimal bank capital, countering the first-order effect on bond debt risk. Bondholders' risk is thereby not materially affected, but shareholder value an...

  9. Monetary Policy Drivers of Bond and Equity Risks

    OpenAIRE

    John Y. Campbell; Pflueger, Carolin; Viceira, Luis Manuel

    2014-01-01

    How do monetary policy rules, monetary policy uncertainty, and macroeconomic shocks affect the risk properties of US Treasury bonds? The exposure of US Treasury bonds to the stock market has moved considerably over time. While it was slightly positive on average over the period 1960-2011, it was unusually high in the 1980s, and negative in the 2000s, a period during which Treasury bonds enabled investors to hedge macroeconomic risks. This paper develops a New Keynesian macroeconomic model wit...

  10. Carbodiimide Inactivation of MMPs and Effect on Dentin Bonding

    OpenAIRE

    Mazzoni, A.; Apolonio, F.M.; Saboia, V.P.A.; de Santi, S; Angeloni, V; Checchi, V.; Curci, R.; Di Lenarda, R.; Tay, F.R.; Pashley, D.H.; Breschi, L.

    2014-01-01

    The use of protein cross-linking agents during bonding procedures has been recently proposed to improve bond durability. This study aimed to use zymography and in situ zymography techniques to evaluate the ability of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) cross-linker to inhibit matrix metalloproteinase (MMP) activity. The hypotheses tested were that: (1) bonding procedures increase dentin gelatinolytic activity and (2) EDC pre-treatment prevents this enzymatic activity. The zym...

  11. Molecular dynamics simulation of the effect of carbon nanotube chirality on nano-joining with gold particle

    International Nuclear Information System (INIS)

    The behavior of gold atoms depending on the CNT chirality in a nanojoining process is studied by molecular dynamics simulation. The deformation regularity and the diffusing characteristic of the gold particle during the joining process, as well as the C-Au bonds distribution in the final joint are studied. Our results show that when joining with higher spirality CNT, gold particle tends to deform more. With the CNT more similar to armchair type, the gold particle as a whole displaces more. In the final joint, the total bonds number decreases from typical armchair CNT to typical zig-zag CNT. However, the bonds distribution in detail is irregular from joint to joint, which is the consequence of lattice structure of both materials. (author)

  12. SPATIO-TEXTUAL SIMILARITY JOIN

    Directory of Open Access Journals (Sweden)

    Ch Shylaja and Supreethi K.P

    2015-07-01

    Full Text Available Data mining is the process of discovering interesting patterns and knowledge from large amounts of data. Spatial databases store large space related data, such as maps, preprocessed remote sensing or medical imaging data. Modern mobile phones and mobile devices are equipped with GPS devices; this is the reason for the Location based services to gain significant attention. These Location based services generate large amounts of spatio- textual data which contain both spatial location and textual description. The spatiotextual objects have different representations because of deviations in GPS or due to different user descriptions. This calls for the need of efficient methods to integrate spatio-textual data. Spatio-textual similarity join meets this need. Spatio-textual similarity join: Given two sets of spatio-textual data, it finds all the similar pairs. Filter and refine framework will be developed to device the algorithms. The prefix filter technique will be extended to generate spatial and textual signatures and inverted indexes will be built on top of these signatures. Candidate pairs will be found using these indexes. Finally the candidate pairs will be refined to get the result. MBR-prefix based signature will be used to prune dissimilar objects. Hybrid signature will be used to support spatial and textual pruning simultaneously.

  13. Transient liquid phase bonding of titanium-, iron- and nickel-based alloys

    Science.gov (United States)

    Rahman, A. H. M. Esfakur

    The operating temperature of land-based gas turbines and jet engines are ever-increasing to increase the efficiency, decrease the emissions and minimize the cost. Within the engines, complex-shaped parts experience extreme temperature, fatigue and corrosion conditions. Ti-based, Ni-based and Fe-based alloys are commonly used in gas turbines and jet engines depending on the temperatures of different sections. Although those alloys have superior mechanical, high temperature and corrosion properties, severe operating conditions cause fast degradation and failure of the components. Repair of these components could reduce lifecycle costs. Unfortunately, conventional fusion welding is not very attractive, because Ti reacts very easily with oxygen and nitrogen at high temperatures, Ni-based superalloys show heat affected zone (HAZ) cracking, and stainless steels show intergranular corrosion and knife-line attack. On the other hand, transient liquid phase (TLP) bonding method has been considered as preferred joining method for those types of alloys. During the initial phase of the current work commercially pure Ti, Fe and Ni were diffusion bonded using commercially available interlayer materials. Commercially pure Ti (Ti-grade 2) has been diffusion bonded using silver and copper interlayers and without any interlayer. With a silver (Ag) interlayer, different intermetallics (AgTi, AgTi2) appeared in the joint centerline microstructure. While with a Cu interlayer eutectic mixtures and Ti-Cu solid solutions appeared in the joint centerline. The maximum tensile strengths achieved were 160 MPa, 502 MPa, and 382 MPa when Ag, Cu and no interlayers were used, respectively. Commercially pure Fe (cp-Fe) was diffusion bonded using Cu (25 m) and Au-12Ge eutectic interlayer (100 microm). Cu diffused predominantly along austenite grain boundaries in all bonding conditions. Residual interlayers appeared at lower bonding temperature and time, however, voids were observed in the joint

  14. Fabrication and integrity test preparation of HIP-joined W and ferritic-martensitic steel mockups for fusion reactor development

    Science.gov (United States)

    Lee, Dong Won; Shin, Kyu In; Kim, Suk Kwon; Jin, Hyung Gon; Lee, Eo Hwak; Yoon, Jae Sung; Choi, Bo Guen; Moon, Se Youn; Hong, Bong Guen

    2014-10-01

    Tungsten (W) and ferritic-martensitic steel (FMS) as armor and structural materials, respectively, are the major candidates for plasma-facing components (PFCs) such as the blanket first wall (BFW) and the divertor, in a fusion reactor. In the present study, three W/FMS mockups were successfully fabricated using a hot isostatic pressing (HIP, 900 °C, 100 MPa, 1.5 hrs) with a following post-HIP heat treatment (PHHT, tempering, 750 °C, 70 MPa, 2 hrs), and the W/FMS joining method was developed based on the ITER BFW and the test blanket module (TBM) development project from 2004 to the present. Using a 10-MHz-frequency flat-type probe to ultrasonically test of the joint, we found no defects in the fabricated mockups. For confirmation of the joint integrity, a high heat flux test will be performed up to the thermal lifetime of the mockup under the proper test conditions. These conditions were determined through a preliminary analysis with conventional codes such as ANSYS-CFX for thermal-hydraulic conditions considering the test facility, the Korea heat load test facility with an electron beam (KoHLT-EB), and its water coolant system at the Korea Atomic Energy Research Institute (KAERI).

  15. Development of the Bonding Representations Inventory to Identify Student Misconceptions about Covalent and Ionic Bonding Representations

    Science.gov (United States)

    Luxford, Cynthia J.; Bretz, Stacey Lowery

    2014-01-01

    Teachers use multiple representations to communicate the concepts of bonding, including Lewis structures, formulas, space-filling models, and 3D manipulatives. As students learn to interpret these multiple representations, they may develop misconceptions that can create problems in further learning of chemistry. Interviews were conducted with 28…

  16. Market presence in China strengthened Network growth and Dual-Chinese-Hub Strategy More frequet Flyer Benefit——Air China and shanhai Airlines Join Star Alliance

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ In the end of 2007, Air China Limited (hereinafter "Air China") and Shanghai Airlines, formally joined Star Alliance at a ceremony held in the new Terminal Three at Beijing Capital International Airport. With the addition of the two Chinese airlines, Star Alliance now has 19 member carriers operating 17,000 daily flights to 897 destinations in 160 countries.

  17. Flexible Friction Stir Joining Technology

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Zhili [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lim, Yong Chae [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Mahoney, Murray [MegaStir Technologies LLC, Orem, UT (United States); Sanderson, Samuel [MegaStir Technologies LLC, Orem, UT (United States); Larsen, Steve [MegaStir Technologies LLC, Orem, UT (United States); Steel, Russel [MegaStir Technologies LLC, Orem, UT (United States); Fleck, Dale [MegaStir Technologies LLC, Orem, UT (United States); Fairchild, Doug P [ExxonMobil, Upstream Research Company (URC), Houston, TX (United States); Wasson, Andrew J [ExxonMobil, Upstream Research Company (URC), Houston, TX (United States); Babb, Jon [MegaStir Technologies LLC, Orem, UT (United States); Higgins, Paul [MegaStir Technologies LLC, Orem, UT (United States)

    2015-07-23

    Reported herein is the final report on a U.S. Department of Energy (DOE) Advanced Manufacturing Office (AMO) project with industry cost-share that was jointly carried out by Oak Ridge National Laboratory (ORNL), ExxonMobil Upstream Research Company (ExxonMobil), and MegaStir Technologies (MegaStir). The project was aimed to advance the state of the art of friction stir welding (FSW) technology, a highly energy-efficient solid-state joining process, for field deployable, on-site fabrications of large, complex and thick-sectioned structures of high-performance and high-temperature materials. The technology innovations developed herein attempted to address two fundamental shortcomings of FSW: 1) the inability for on-site welding and 2) the inability to weld thick section steels, both of which have impeded widespread use of FSW in manufacturing. Through this work, major advance has been made toward transforming FSW technology from a “specialty” process to a mainstream materials joining technology to realize its pervasive energy, environmental, and economic benefits across industry.

  18. Prediction of allosteric sites and mediating interactions through bond-to-bond propensities

    Science.gov (United States)

    Amor, B. R. C.; Schaub, M. T.; Yaliraki, S. N.; Barahona, M.

    2016-08-01

    Allostery is a fundamental mechanism of biological regulation, in which binding of a molecule at a distant location affects the active site of a protein. Allosteric sites provide targets to fine-tune protein activity, yet we lack computational methodologies to predict them. Here we present an efficient graph-theoretical framework to reveal allosteric interactions (atoms and communication pathways strongly coupled to the active site) without a priori information of their location. Using an atomistic graph with energy-weighted covalent and weak bonds, we define a bond-to-bond propensity quantifying the non-local effect of instantaneous bond fluctuations propagating through the protein. Significant interactions are then identified using quantile regression. We exemplify our method with three biologically important proteins: caspase-1, CheY, and h-Ras, correctly predicting key allosteric interactions, whose significance is additionally confirmed against a reference set of 100 proteins. The almost-linear scaling of our method renders it suitable for high-throughput searches for candidate allosteric sites.

  19. Prediction of allosteric sites and mediating interactions through bond-to-bond propensities

    Science.gov (United States)

    Amor, B. R. C.; Schaub, M. T.; Yaliraki, S. N.; Barahona, M.

    2016-01-01

    Allostery is a fundamental mechanism of biological regulation, in which binding of a molecule at a distant location affects the active site of a protein. Allosteric sites provide targets to fine-tune protein activity, yet we lack computational methodologies to predict them. Here we present an efficient graph-theoretical framework to reveal allosteric interactions (atoms and communication pathways strongly coupled to the active site) without a priori information of their location. Using an atomistic graph with energy-weighted covalent and weak bonds, we define a bond-to-bond propensity quantifying the non-local effect of instantaneous bond fluctuations propagating through the protein. Significant interactions are then identified using quantile regression. We exemplify our method with three biologically important proteins: caspase-1, CheY, and h-Ras, correctly predicting key allosteric interactions, whose significance is additionally confirmed against a reference set of 100 proteins. The almost-linear scaling of our method renders it suitable for high-throughput searches for candidate allosteric sites. PMID:27561351

  20. Molecular dynamics simulations of the hydration of poly(vinyl methyl ether): Hydrogen bonds and quasi-hydrogen bonds

    Institute of Scientific and Technical Information of China (English)

    WU RongLiang; JI Qing; KONG Bin; YANG XiaoZhen

    2008-01-01

    Atomistic detailed hydration structures of poly(vinyl methyl ether) (PVME) have been investigated by molecular dynamics simulations under 300 K at various concentrations. Both radial distribution func-tions and the distance distributions between donors and acceptors in hydrogen bonds show that the hydrogen bonds between the polymer and water are shorter by 0.005 nm than those between water molecules. The Quasi-hydrogen bonds take only 7.2% of the van der Waals interaction pairs. It was found the hydrogen bonds are not evenly distributed along the polymer chain, and there still exists a significant amount (10%) of ether oxygen atoms that are not hydrogen bonded to water at a concentra-tion as low as 3.3%. This shows that in polymer solutions close contacts occur not only between polymer chains but also between chain segments within the polymer, which leads to inefficient con-tacts between ether oxygen atoms and water molecules. Variation of the quasi-hydrogen bonds with the concentration is similar to that of hydrogen bonds, but the ratio of the repeat units forming quasi-hydrogen bonds to those forming hydrogen bonds approaches 0.2. A transition was found in the demixing enthalpy at around 30% measured by dynamic testing differential scanning calorimetry (DTDSC) for aqueous solutions of a mono-dispersed low molecular weight PVME, which can be related to the transition of the fractions of hydrogen bonds and quasi-hydrogen bonds at ~27%. The transition of the fractions of hydrogen bonds and quasi-hydrogen bonds at ~27% can be used to explain the demixing enthalpy transition at 30% at a molecular scale. In addition, at the concentration of 86%, each ether oxygen atom bonded with water is assigned 1.56 water molecules on average, and 'free' water molecules emerge at the concentration of around 54%.

  1. Molecular dynamics simulations of the hydration of poly(vinyl methyl ether):Hydrogen bonds and quasi-hydrogen bonds

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Atomistic detailed hydration structures of poly(vinyl methyl ether)(PVME) have been investigated by molecular dynamics simulations under 300 K at various concentrations. Both radial distribution functions and the distance distributions between donors and acceptors in hydrogen bonds show that the hydrogen bonds between the polymer and water are shorter by 0.005 nm than those between water molecules. The Quasi-hydrogen bonds take only 7.2% of the van der Waals interaction pairs. It was found the hydrogen bonds are not evenly distributed along the polymer chain,and there still exists a significant amount(10%) of ether oxygen atoms that are not hydrogen bonded to water at a concentration as low as 3.3%. This shows that in polymer solutions close contacts occur not only between polymer chains but also between chain segments within the polymer,which leads to inefficient contacts between ether oxygen atoms and water molecules. Variation of the quasi-hydrogen bonds with the concentration is similar to that of hydrogen bonds,but the ratio of the repeat units forming quasi-hydrogen bonds to those forming hydrogen bonds approaches 0.2. A transition was found in the demixing enthalpy at around 30% measured by dynamic testing differential scanning calorimetry(DTDSC) for aqueous solutions of a mono-dispersed low molecular weight PVME,which can be related to the transition of the fractions of hydrogen bonds and quasi-hydrogen bonds at ~27%. The transition of the fractions of hydrogen bonds and quasi-hydrogen bonds at ~27% can be used to explain the demixing enthalpy transition at 30% at a molecular scale. In addition,at the concentration of 86%,each ether oxygen atom bonded with water is assigned 1.56 water molecules on average,and ’free’ water molecules emerge at the concentration of around 54%.

  2. Bond breaking in a Morse chain under tension: Fragmentation patterns, higher index saddles, and bond healing

    Science.gov (United States)

    Mauguière, F. A. L.; Collins, P.; Ezra, G. S.; Wiggins, S.

    2013-04-01

    We investigate the fragmentation dynamics of an atomic chain under tensile stress. We have classified the location, stability type (indices), and energy of all equilibria for the general n-particle chain, and have highlighted the importance of saddle points with index >1. We show that for an n = 2-particle chain under tensile stress the index 2 saddle plays a central role in organizing the dynamics. We apply normal form theory to analyze phase space structure and dynamics in a neighborhood of the index 2 saddle. We define a phase dividing surface (DS) that enables us to classify trajectories passing through a neighborhood of the saddle point using the values of the integrals associated with the normal form. We also generalize our definition of the dividing surface and define an extended dividing surface (EDS), which is used to sample and classify all trajectories that pass through a phase space neighborhood of the index 2 saddle at total energies less than that of the saddle. Classical trajectory simulations are used to study fragmentation patterns for the n = 2 chain under tension. That is, we investigate the relative probability for breaking one bond versus concerted fission of several (two, in this case) bonds. Initial conditions for trajectories are obtained by sampling the EDS at constant energy. We sample trajectories at fixed energies both above and below the energy of the saddle. The fate of trajectories (single versus multiple bond breakage) is explored as a function of the location of the initial condition on the EDS, and a connection made to the work of Chesnavich on collision-induced dissociation. A significant finding is that we can readily identify trajectories that exhibit bond healing. Such trajectories pass outside the nominal (index 1) transition state for single bond dissociation, but return to the potential well region, possibly several times, before ultimately dissociating.

  3. Steam turbines of scientific and industrial joining 'Turboatom' , their features and perfecting ways

    International Nuclear Information System (INIS)

    The article deals with the specific features of steam turbines for TPPs and NPPs developed by Turboatom Research and Production Association. Design diagrams of advanced turbines, including modified, are considered. Operation experience of turbines and turbine plants is analysed. 9 refs., 6 figs., 1 tab

  4. CHALCO and Guangxi Government Joined Forces to Drive Forward Optimization and Upgrading of Rare Earth Industry

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>In early June, Ding Haiyan, Assistant to General Manager of CHALCO and President of China Rare Metals And Rare Earth Corporation, met with Yang Daoxi, Vice Chairman of the People’s Congress of Guangxi Zhuang Autonomous Region in Nanning, and exchanged views on further development of Guangxi rare

  5. Mechanical strength and analysis of fracture of titanium joining submitted to laser and tig welding

    Directory of Open Access Journals (Sweden)

    Ana Cláudia Gabrielli Piveta

    2012-12-01

    Full Text Available This study compared the tensile strength and fracture mechanism of tungsten inert gas (TIG welds in cylindrical rods of commercially pure titanium (cp Ti with those of laser welds and intact samples. Thirty dumbbell-shaped samples were developed by using brass rods as patterns. The samples were invested in casings, subjected to thermal cycles, and positioned in a plasma arc welding machine under argon atmosphere and vacuum, and titanium was injected under vacuum/pressure. The samples were X-rayed to detect possible welding flaws and randomly assigned to three groups to test the tensile strength and the fracture mechanism: intact, laser welding, and TIG welding. The tensile test results were investigated using ANOVA, which indicated that the samples were statistically similar. The fracture analysis showed that the cpTi samples subjected to laser welding exhibited brittle fracture and those subjected to TIG welding exhibited mixed brittle/ductile fracture with a predominance of ductile fracture with the presence of microcavities and cleavage areas. Intact samples presented the characteristic straightening in the fracture areas, indicating the ductility of the material.

  6. Why Women Join the Military: Enlistment Decisions and Postdeployment Experiences of Service Members and Veterans.

    Science.gov (United States)

    Mankowski, Mariann; Tower, Leslie E; Brandt, Cynthia A; Mattocks, Kristin

    2015-10-01

    Over the past three decades women's enlistment has continued to increase. In an effort to help social workers better meet the needs of female veterans, this study sought to learn women's enlistment motivations and postdeployment experiences. This qualitative study was nested within the Women Veterans Cohort Study. Using a semistructured interview guide, authors interviewed 18 enlisted female service members and veterans. The themes that emerged, based on grounded theory, included not only opportunity and calling, but also outcomes. Unexpectedly, enlistment resulted in a professional military career, with over half of the participants making the military their life's work. Further study on the motivation, retention, and the reintegration needs of women postmilitary is necessary, particularly with military recruitment targets of 20 percent women by the year 2020 and the increased awareness of the military as a potentially hostile work environment for women.

  7. Comparison of joining efficiency and residual stresses in laser and laser hybrid welding

    OpenAIRE

    Suder, Wojciech; Ganguly, Supriyo; Williams, Stewart W.; Paradowska, A.M; Colegrove, Paul A.

    2011-01-01

    Laser welding is a high energy density process, which can produce welds with less energy input and thereby lower residual stress generation compared to arc welding processes. However, the narrow beam dimension makes it extremely sensitive in terms of fit up tolerance. This causes a problem in achieving high quality welds. Laser with arc hybrid process overcomes such issues. In this paper, longitudinal residual strains were compared for autogenous laser welding and laser/TIG ...

  8. Disulfide bonds and glycosylation in fungal peroxidases.

    Science.gov (United States)

    Limongi, P; Kjalke, M; Vind, J; Tams, J W; Johansson, T; Welinder, K G

    1995-01-15

    Four conserved disulfide bonds and N-linked and O-linked glycans of extracellular fungal peroxidases have been identified from studies of a lignin and a manganese peroxidase from Trametes versicolor, and from Coprinus cinereus peroxidase (CIP) and recombinant C. cinereus peroxidase (rCIP) expressed in Aspergillus oryzae. The eight cysteine residues are linked 1-3, 2-7, 4-5 and 6-8, and are located differently from the four conserved disulfide bridges present in the homologous plant peroxidases. CIP and rCIP were identical in their glycosylation pattern, although the extent of glycan chain heterogeneity depended on the fermentation batch. CIP and rCIP have one N-linked glycan composed only of GlcNAc and Man at residue Asn142, and two O-linked glycans near the C-terminus. The major glycoform consists of single Man residues at Thr331 and at Ser338. T. versicolor lignin isoperoxidase TvLP10 contains a single N-linked glycan composed of (GlcNAc)2Man5 bound to Asn103, whereas (GlcNAc)2Man3 was found in T. versicolor manganese isoperoxidase TvMP2 at the same position. In addition, mass spectrometry of the C-terminal peptide of TvMP2 indicated the presence of five Man residues in O-linked glycans. No phosphate was found in these fungal peroxidases. PMID:7851395

  9. Disulfide bonds and glycosylation in fungal peroxidases.

    Science.gov (United States)

    Limongi, P; Kjalke, M; Vind, J; Tams, J W; Johansson, T; Welinder, K G

    1995-01-15

    Four conserved disulfide bonds and N-linked and O-linked glycans of extracellular fungal peroxidases have been identified from studies of a lignin and a manganese peroxidase from Trametes versicolor, and from Coprinus cinereus peroxidase (CIP) and recombinant C. cinereus peroxidase (rCIP) expressed in Aspergillus oryzae. The eight cysteine residues are linked 1-3, 2-7, 4-5 and 6-8, and are located differently from the four conserved disulfide bridges present in the homologous plant peroxidases. CIP and rCIP were identical in their glycosylation pattern, although the extent of glycan chain heterogeneity depended on the fermentation batch. CIP and rCIP have one N-linked glycan composed only of GlcNAc and Man at residue Asn142, and two O-linked glycans near the C-terminus. The major glycoform consists of single Man residues at Thr331 and at Ser338. T. versicolor lignin isoperoxidase TvLP10 contains a single N-linked glycan composed of (GlcNAc)2Man5 bound to Asn103, whereas (GlcNAc)2Man3 was found in T. versicolor manganese isoperoxidase TvMP2 at the same position. In addition, mass spectrometry of the C-terminal peptide of TvMP2 indicated the presence of five Man residues in O-linked glycans. No phosphate was found in these fungal peroxidases.

  10. Submap joining smoothing and mapping for camera-based indoor localization and mapping

    Science.gov (United States)

    Bjärkefur, J.; Karlsson, A.; Grönwall, C.; Rydell, J.

    2011-06-01

    Personnel positioning is important for safety in e.g. emergency response operations. In GPS-denied environments, possible positioning solutions include systems based on radio frequency communication, inertial sensors, and cameras. Many camera-based systems create a map and localize themselves relative to that. The computational complexity of most such solutions grows rapidly with the size of the map. One way to reduce the complexity is to divide the visited region into submaps. This paper presents a novel method for merging conditionally independent submaps (generated using e.g. EKF-SLAM) by the use of smoothing. Using this approach it is possible to build large maps in close to linear time. The method is demonstrated in two indoor scenarios, where data was collected with a trolley-mounted stereo vision camera.

  11. Risk and Return: Bonds and Sukuk in Indonesia

    Directory of Open Access Journals (Sweden)

    Ahmad Rodoni

    2016-07-01

    Full Text Available The aim of this research is to compare the degree of risk and return of bonds with sukuk, using several calculations magnitudes, which are, yield to maturity (YTM, Macaulay's duration, and Value at Risk (VaR. The results of this study show that there is no significant difference between the YTM bonds and the YTM of emitted sukuk. Using the Macaulay’s duration formula to evaluate the duration of bonds and sukuk, the research found out that there is no significant difference in the duration of bonds and sukuk. However, the calculation and comparison of the VaR, showed a significant differences between bonds and sukuk , likewise either the comparison of the VaR of a sample group of bonds with a sample group of sukuk using k sample test. But by testing each group of the VaR of bonds sample group and sukuk sample group,the results show no significant differences.DOI: 10.15408/aiq.v8i2.3159

  12. Exploring the Intricacies of Weak Interactions in Metal-Metal Bonds Using an Unsymmetrical Carbonyl Precursor and a Triple-Bonded W2(6+) Paddlewheel.

    Science.gov (United States)

    Chiarella, Gina M; Feng, Chao; Murillo, Carlos A; Zhao, Qinliang

    2016-09-19

    Stepwise reaction of W(CO)6 with tetramethylated bicyclic guanidinate ligands, characterized by a central C(N)3 unit joining two fused six-membered rings with CH2CMe2CH2 units spanning two of the nitrogen atoms, allowed isolation of W2(μ-CO)2(μ-TMhpp)2(η(2)-TMhpp)2, 1, a precursor of W2(TMhpp)4Cl2 ( J. Am. Chem. Soc. 2013 , 135 , 17889 ; TMhpp = [(CH2CMe2CH2)2(C(N)3)]). Subsequent heating of 1 followed by reaction with TlPF6 generates [W2(TMhpp)4](PF6)2, 2. Compound 1 has an edge-sharing bioctahedral (ESBO) arrangement with a W2(μ-CO)2(4+) core having semibridging carbonyl groups, while 2 has a paddlewheel structure with a W2(6+) core spanned by four tetramethyl-substituted bicyclic guanidinate ligands. This compound also has hexafluorophosphate anions along the metal-metal bond that are nestled within methylene groups with the aid of a network of weak C-H···F interactions that prevent a close approach of the fluorine atoms to the dimetal unit. Theoretical computations were carried out on ditungsten model complexes supported by three ligand sets: bicyclic guanidinate, guanidinate, and formamidinate. The computations show that the π-accepting ability of the carbonyl groups significantly lowers the energy of the σ* orbital, and thus, the energy falls below that of the δ orbital. This information along with the diamagnetism of both 1 and 2-as shown by the sharp signals in the (1)H NMR spectra that support a lack of unpaired electrons (S = 0)-is consistent with the electronic configuration of σ(2)π(2)σ*(2)δ(2) (π(2)δ(2)) and thus a formal bond order of 2 for 1 and σ(2)π(4) for the triple-bonded W2(6+) core in 2. A comparison of the W-W bond lengths in 2, its chloro precursor W2(TMhpp)4Cl2, and the corresponding analogue W2(hpp)4Cl2 shows a substantial effect from the axially coordinated ligand, distal lone pair in determining the length of the metal-metal bond for these paddlewheel species. The importance of the ligands in tuning the energy level of

  13. Development of Be/Glidcop joint obtained by hot isostatic pressing diffusion bonding for high in-service temperature

    Energy Technology Data Exchange (ETDEWEB)

    Saint-Antonin, F.; Bucci, P.; Burlet, H.; Le Marois, G. [CEA Centre d`Etudes de Grenoble, 38 (France); Barberi, D.; Laille, A.

    1998-01-01

    This paper addresses some aspects of the beryllium-Glidcop joining by Hot Isostatic Pressing diffusion Bonding. The quality of a joint is mainly dependent on the interface microstructure. Thus, as Be/copper direct bonding is not recommended, the choice of interlayers is a critical point. The joining process parameters, i.e. temperature, pressure and time, must take into account the in-service requirements, the mechanical and metallurgical properties of each material. The Be/Glidcop joining process developed at CEA/Grenoble is presented here. (author)

  14. Study of diffusion bonding of Ti-6Al-4V and ZQSn10-10 with metal interlayer

    Institute of Scientific and Technical Information of China (English)

    Zhao Huanling; Zhao He; Feng Jicai; Song Minxia; Zhao Xihua

    2008-01-01

    The diffusion bonding was carried out to join Ti alloy (Ti-6Al-4V) and tin-bronze (ZQSn10-10) with Ni and Ni+Cu interlayer. The microstructures of the diffusion bonded joints were analyzed by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The results show that when the interlayer is Ni or Ni+Cu transition metals both could effectively prevent the diffusion between Ti and Cu and avoid the formation of the Cu-Ti intermetallic compounds (Cu3Ti, CuTi etc.). But the Ni-Ti intermetallic compounds (NiTi, Ni3Ti) are formed on the Ti-6Al-4V/Ni interface. When the interlayer is Ni, the optimum bonding parameters are 830℃/10 MPa/30min. And when the interlayer is Ni+Cu, the optimum bonding parameters are 850℃/10MPa/20min. With the optimum bonding parameters, the tensile strength of the joints with Ni and Ni+Cu interlayer both are 155.8MPa, which is 65 percent of the strength of ZQSn10-10 base metal.

  15. A simple surface treatment and characterization of AA 6061 aluminum alloy surface for adhesive bonding applications

    Energy Technology Data Exchange (ETDEWEB)

    Saleema, N., E-mail: saleema.noormohammed@imi.cnrc-nrc.gc.ca [National Research Council of Canada (ATC-NRC), 501 Boulevard University East, Saguenay, Quebec G7H 8C3 (Canada); Sarkar, D.K. [Centre Universitaire de Recherche sur l' Aluminium (CURAL), University of Quebec at Chicoutimi (UQAC), 555 Boulevard University East, Saguenay, Quebec G7H 2B1 (Canada); Paynter, R.W. [Institut National de la Recherche Scientifique Energie Materiaux Telecommunications (INRS-EMT), 1650 Boulevard Lionel-Boulet, Varennes, Quebec J3X 1S2 (Canada); Gallant, D.; Eskandarian, M. [National Research Council of Canada (ATC-NRC), 501 Boulevard University East, Saguenay, Quebec G7H 8C3 (Canada)

    2012-11-15

    Highlights: Black-Right-Pointing-Pointer A very simple surface treatment method to achieve excellent and durable aluminum adhesive bonding. Black-Right-Pointing-Pointer Our method involves simple immersion of aluminum in very dilute NaOH solution at room temperature with no involvement of strong acids or multiple procedures. Black-Right-Pointing-Pointer Surface analysis via various surface characterization techniques showed morphological and chemical modifications favorable for obtaining highly durable bond strengths on the treated surface. Black-Right-Pointing-Pointer Safe, economical, reproducible and simple method, easily applicable in industries. - Abstract: Structural adhesive bonding of aluminum is widely used in aircraft and automotive industries. It has been widely noted that surface preparation of aluminum surfaces prior to adhesive bonding plays a significant role in improving the strength of the adhesive bond. Surface cleanliness, surface roughness, surface wettability and surface chemistry are controlled primarily by proper surface treatment methods. In this study, we have employed a very simple technique influencing all these criteria by simply immersing aluminum substrates in a very dilute solution of sodium hydroxide (NaOH) and we have studied the effect of varying the treatment period on the adhesive bonding characteristics. A bi-component epoxy adhesive was used to join the treated surfaces and the bond strengths were evaluated via single lap shear (SLS) tests in pristine as well as degraded conditions. Surface morphology, chemistry, crystalline nature and wettability of the NaOH treated surfaces were characterized using various surface analytical tools such as scanning electron microscopy and energy dispersive X-ray analysis (SEM/EDX), optical profilometry, infrared reflection absorption spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction and contact angle goniometry. Excellent adhesion characteristics with complete cohesive failure

  16. Effect of thione primers on adhesive bonding between an indirect composite material and Ag-Pd-Cu-Au alloy.

    Science.gov (United States)

    Imai, Hideyuki; Koizumi, Hiroyasu; Shimoe, Saiji; Hirata, Isao; Matsumura, Hideo; Nikawa, Hiroki

    2014-01-01

    The current study evaluated the effect of primers on the shear bond strength of an indirect composite material joined to a silverpalladium-copper-gold (Ag-Pd-Cu-Au) alloy (Castwell). Disk specimens were cast from the alloy and were air-abraded with alumina. Eight metal primers were applied to the alloy surface. A light-polymerized indirect composite material (Solidex) was bonded to the alloy. Shear bond strength was determined both before and after the application of thermocycling. Two groups primed with Metaltite (thione) and M. L. Primer (sulfide) showed the greatest post-thermocycling bond strength (8.8 and 6.5 MPa). The results of the X-ray photoelectron spectroscopic (XPS) analysis suggested that the thione monomer (MTU-6) in the Metaltite primer was strongly adsorbed onto the Ag-Pd-Cu-Au alloy surface even after repeated cleaning with acetone. The application of either the thione (MTU-6) or sulfide primer is effective for enhancing the bonding between a composite material and Ag-Pd-Cu-Au alloy.

  17. Failure of dissimilar material bonded joints

    Science.gov (United States)

    Konstantakopoulou, M.; Deligianni, A.; Kotsikos, G.

    2016-03-01

    Joining of materials in structural design has always been a challenge for engineers. Bolting and riveting has been used for many years, until the emergence of fusion welding which revolutionised construction in areas such as shipbuilding, automotive, infrastructure and consumer goods. Extensive research in the past 50 years has resulted in better understanding of the process and minimised the occurrence of failures associated with fusion welding such as, residual stress cracking, stress corrosion and corrosion fatigue cracking, localised reduction in mechanical properties due to microstructural changes (heat affected zone) etc. Bonding has been a technique that has been proposed as an alternative because it eliminates several of the problems associated with fusion welding. But, despite some applications it has not seen wide use. There is however a renewed interest in adhesively bonded joints, as designers look for ever more efficient structures which inevitably leads to the use and consequently joining of combinations of lightweight materials, often with fundamentally different mechanical and physical properties. This chapter provides a review of adhesively bonded joints and reports on improvements to bonded joint strength through the introduction of carbon nanotubes at the bond interface. Results from various workers in the field are reported as well as the findings of the authors in this area of research. It is obvious that there are several challenges that need to be addressed to further enhance the strength of bonded joints and worldwide research is currently underway to address those shortcomings and build confidence in the implementation of these new techniques.

  18. Development of HIP bonding procedure and mechanical properties of HIP bonded joints for reduced activation ferritic steel F-82H

    International Nuclear Information System (INIS)

    Structural materials of blanket components in fusion DEMO reactors will receive a neutron wall load more than 3-5MW/m2 as well as exposed by surface heat flux more than 0.5MW/m2. A reduced activation ferritic steel F-82H has been developed by JAERI in collaboration with NKK from viewpoints of resistance for high temperature and neutron loads and lower radioactivity. This study intends to obtain basic performance of F-82H to establish the fabrication procedure of the first wall and blanket box by using Hot Isostatic Pressing (HIP) bonding. Before HIP bonding tests, effects of heat treatment temperature and surface roughness on mechanical properties of joints were investigated in the heat treatment tests and diffusion bonding tests, respectively. From these results, the optimum HIP bonding conditions and the post heat treatment were selected. Using these conditions, the HIP bonding tests were carried out to evaluate HIP bondability and to obtain mechanical properties of the joints. Sufficient HIP bonding performance was obtained under the temperature of 1040degC, the compressive stress of 150MPa, the holding time of 2h, and the surface roughness ∼μ m. Mechanical properties of HIP bonded joints with these conditions were similar to those of as-received base metal. An oxide formation on the surface to be bonded would need to be avoided for sufficient bonding. The bonding ratio, Charpy impact value and fatigue performance of the joints strongly depended on the HIP conditions, especially temperature, while micro-structure, Vickers hardness and tensile properties had little dependence on the HIP temperature. The surface roughness strongly affected the bonding ratio and would be required to be in the level of a few μ m. In the HIP bonding test of the welded material, the once-melted surface could be jointed by the HIP bonding under the above-mentioned procedure. (J.P.N.)

  19. Theoretical Electron Density Distributions for Fe- and Cu-Sulfide Earth Materials: A Connection between Bond Length, Bond Critical Point Properties, Local Energy Densities, and Bonded Interactions

    Energy Technology Data Exchange (ETDEWEB)

    Gibbs, Gerald V.; Cox, David F.; Rosso, Kevin M.; Ross, Nancy L.; Downs, R. T.; Spackman, M. A.

    2007-03-01

    Bond critical point and local energy density properties together with net atomic charges were calculated for theoretical electron density distributions, F(r), generated for a variety of Fe and Cu metal-sulfide materials with high- and low-spin Fe atoms in octahedral coordination and high-spin Fe atoms in tetrahedral coordination. The electron density, F(rc), the Laplacian, 32F(rc), the local kinetic energy, G(rc), and the oxidation state of Fe increase as the local potential energy density, V(rc), the Fe-S bond lengths, and the coordination numbers of the Fe atoms decrease. The properties of the bonded interactions for the octahedrally coordinated low-spin Fe atoms for pyrite and marcasite are distinct from those for high-spin Fe atoms for troilite, smythite, and greigite. The Fe-S bond lengths are shorter and the values of F(rc) and 32F(rc) are larger for pyrite and marcasite, indicating that the accumulation and local concentration of F(r) in the internuclear region are greater than those involving the longer, high-spin Fe-S bonded interactions. The net atomic charges and the bonded radii calculated for the Fe and S atoms in pyrite and marcasite are also smaller than those for sulfides with high-spin octahedrally coordinated Fe atoms. Collectively, the Fe-S interactions are indicated to be intermediate in character with the low-spin Fe-S interactions having greater shared character than the highspin interactions. The bond lengths observed for chalcopyrite together with the calculated bond critical point properties are consistent with the formula Cu+Fe3+S2. The bond length is shorter and the F(rc) value is larger for the FeS4 tetrahedron displayed by metastable greigite than those displayed by chalcopyrite and cubanite, consistent with a proposal that the Fe atom in greigite is tetravalent. S-S bond paths exist between each of the surface S atoms of adjacent slabs of FeS6 octahedra comprising the layer sulfide smythite, suggesting that the neutral Fe3S4 slabs are

  20. Theoretical electron density distributions for Fe- and Cu-sulfide earth materials: a connection between bond length, bond critical point properties, local energy densities, and bonded interactions.

    Science.gov (United States)

    Gibbs, G V; Cox, D F; Rosso, K M; Ross, N L; Downs, R T; Spackman, M A

    2007-03-01

    Bond critical point and local energy density properties together with net atomic charges were calculated for theoretical electron density distributions, rho(r), generated for a variety of Fe and Cu metal-sulfide materials with high- and low-spin Fe atoms in octahedral coordination and high-spin Fe atoms in tetrahedral coordination. The electron density, rho(rc), the Laplacian, triangle down2rho(rc), the local kinetic energy, G(rc), and the oxidation state of Fe increase as the local potential energy density, V(rc), the Fe-S bond lengths, and the coordination numbers of the Fe atoms decrease. The properties of the bonded interactions for the octahedrally coordinated low-spin Fe atoms for pyrite and marcasite are distinct from those for high-spin Fe atoms for troilite, smythite, and greigite. The Fe-S bond lengths are shorter and the values of rho(rc) and triangle down2rho(rc) are larger for pyrite and marcasite, indicating that the accumulation and local concentration of rho(r) in the internuclear region are greater than those involving the longer, high-spin Fe-S bonded interactions. The net atomic charges and the bonded radii calculated for the Fe and S atoms in pyrite and marcasite are also smaller than those for sulfides with high-spin octahedrally coordinated Fe atoms. Collectively, the Fe-S interactions are indicated to be intermediate in character with the low-spin Fe-S interactions having greater shared character than the high-spin interactions. The bond lengths observed for chalcopyrite together with the calculated bond critical point properties are consistent with the formula Cu+Fe3+S2. The bond length is shorter and the rho(rc) value is larger for the FeS4 tetrahedron displayed by metastable greigite than those displayed by chalcopyrite and cubanite, consistent with a proposal that the Fe atom in greigite is tetravalent. S-S bond paths exist between each of the surface S atoms of adjacent slabs of FeS6 octahedra comprising the layer sulfide smythite

  1. Transistor bonding pad configuration for uniform injection and low inductance

    Science.gov (United States)

    Jacobson, D. S.

    1970-01-01

    Modification of process for fabricating transistors, which comprises a metallization-pattern design for emitter and base areas together with a double bonding configuration for each emitter and base-bonding lead, improves uniformity of carrier injection in transistors and of reducing lead inductances at base-emitter terminals.

  2. Resin-Bonded Bridges in vitro and in vivo

    NARCIS (Netherlands)

    Veen, Johannes Hilbrandt van der

    1988-01-01

    In this thesis in vitro and in vivo studies on the clinical application of resin-bonded bridges are described and discussed. The development of different types of resin-bonded bridges is described in chapter 1. The bridges are often made by boding a cast metal retainer fitted with and artificial too

  3. 40 CFR 35.6590 - Bonding and insurance.

    Science.gov (United States)

    2010-07-01

    ... STATE AND LOCAL ASSISTANCE Cooperative Agreements and Superfund State Contracts for Superfund Response Actions Procurement Requirements Under A Cooperative Agreement § 35.6590 Bonding and insurance. (a) General. The recipient must meet the requirements regarding bonding described in 40 CFR 31.36(h)....

  4. Bond Issues.

    Science.gov (United States)

    Pollack, Rachel H.

    2000-01-01

    Notes trends toward increased borrowing by colleges and universities and offers guidelines for institutions that are considering issuing bonds to raise money for capital projects. Discussion covers advantages of using bond financing, how use of bonds impacts on traditional fund raising, other cautions and concerns, and some troubling aspects of…

  5. Homologous recombination and non-homologous end-joining repair pathways in bovine embryos with different developmental competence

    International Nuclear Information System (INIS)

    This study investigated the expression of genes controlling homologous recombination (HR), and non-homologous end-joining (NHEJ) DNA-repair pathways in bovine embryos of different developmental potential. It also evaluated whether bovine embryos can respond to DNA double-strand breaks (DSBs) induced with ultraviolet irradiation by regulating expression of genes involved in HR and NHEJ repair pathways. Embryos with high, intermediate or low developmental competence were selected based on the cleavage time after in vitro insemination and were removed from in vitro culture before (36 h), during (72 h) and after (96 h) the expected period of embryonic genome activation. All studied genes were expressed before, during and after the genome activation period regardless the developmental competence of the embryos. Higher mRNA expression of 53BP1 and RAD52 was found before genome activation in embryos with low developmental competence. Expression of 53BP1, RAD51 and KU70 was downregulated at 72 h and upregulated at 168 h post-insemination in response to DSBs induced by ultraviolet irradiation. In conclusion, important genes controlling HR and NHEJ DNA-repair pathways are expressed in bovine embryos, however genes participating in these pathways are only regulated after the period of embryo genome activation in response to ultraviolet-induced DSBs.

  6. Homologous recombination and non-homologous end-joining repair pathways in bovine embryos with different developmental competence

    Energy Technology Data Exchange (ETDEWEB)

    Henrique Barreta, Marcos [Universidade Federal de Santa Catarina, Campus Universitario de Curitibanos, Curitibanos, SC (Brazil); Laboratorio de Biotecnologia e Reproducao Animal-BioRep, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Garziera Gasperin, Bernardo; Braga Rissi, Vitor; Cesaro, Matheus Pedrotti de [Laboratorio de Biotecnologia e Reproducao Animal-BioRep, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Ferreira, Rogerio [Centro de Educacao Superior do Oeste-Universidade do Estado de Santa Catarina, Chapeco, SC (Brazil); Oliveira, Joao Francisco de; Goncalves, Paulo Bayard Dias [Laboratorio de Biotecnologia e Reproducao Animal-BioRep, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Bordignon, Vilceu, E-mail: vilceu.bordignon@mcgill.ca [Department of Animal Science, McGill University, Ste-Anne-De-Bellevue, QC (Canada)

    2012-10-01

    This study investigated the expression of genes controlling homologous recombination (HR), and non-homologous end-joining (NHEJ) DNA-repair pathways in bovine embryos of different developmental potential. It also evaluated whether bovine embryos can respond to DNA double-strand breaks (DSBs) induced with ultraviolet irradiation by regulating expression of genes involved in HR and NHEJ repair pathways. Embryos with high, intermediate or low developmental competence were selected based on the cleavage time after in vitro insemination and were removed from in vitro culture before (36 h), during (72 h) and after (96 h) the expected period of embryonic genome activation. All studied genes were expressed before, during and after the genome activation period regardless the developmental competence of the embryos. Higher mRNA expression of 53BP1 and RAD52 was found before genome activation in embryos with low developmental competence. Expression of 53BP1, RAD51 and KU70 was downregulated at 72 h and upregulated at 168 h post-insemination in response to DSBs induced by ultraviolet irradiation. In conclusion, important genes controlling HR and NHEJ DNA-repair pathways are expressed in bovine embryos, however genes participating in these pathways are only regulated after the period of embryo genome activation in response to ultraviolet-induced DSBs.

  7. 45 CFR 1309.23 - Insurance, bonding and maintenance.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Insurance, bonding and maintenance. 1309.23 Section 1309.23 Public Welfare Regulations Relating to Public Welfare (Continued) OFFICE OF HUMAN... of Federal Interest § 1309.23 Insurance, bonding and maintenance. (a) At the time of acquiring...

  8. Bond-Energy and Surface-Energy Calculations in Metals

    Science.gov (United States)

    Eberhart, James G.; Horner, Steve

    2010-01-01

    A simple technique appropriate for introductory materials science courses is outlined for the calculation of bond energies in metals from lattice energies. The approach is applied to body-centered cubic (bcc), face-centered cubic (fcc), and hexagonal-closest-packed (hcp) metals. The strength of these bonds is tabulated for a variety metals and is…

  9. Breastfeeding, Bonding, and the Mother-Infant Relationship.

    Science.gov (United States)

    Else-Quest, Nicole M.; Hyde, Janet Shibley; Clark, Roseanne

    2003-01-01

    Analyzed data from a longitudinal study of 570 mother-infant pairs to test the bonding hypothesis and the good-enough caregiver hypothesis as they relate to breastfeeding with maternal bonding and the mother-infant relationship. Found that breastfeeding dyads tended to show higher-quality relationships at 12 months than did bottle-feeding dyads.…

  10. The emerging project bond market - covenant provisions and credit spreads

    OpenAIRE

    Dailami, Mansoor; Hauswald, Robert

    2003-01-01

    The emergence in the 1990s of a nascent project bond market to fund long-term infrastructure projects in developing countries merits attention. The authors compile detailed information on a sample of 105 bonds issued between January 1993 and March 2002 for financing infrastructure projects in developing countries, document their contractual covenants, and analyze their pricing determinants...

  11. Oxytocin and mutual communication in mother-infant bonding

    Directory of Open Access Journals (Sweden)

    Miho eNagasawa

    2012-02-01

    Full Text Available Mother-infant bonding is universal to all mammalian species. In this review, we describe the manner in which reciprocal communication between the mother and infant leads to mother-infant bonding in rodents. In rats and mice, mother-infant bond formation is reinforced by various social stimuli, such as tactile stimuli and ultrasonic vocalizations from the pups to the mother, and feeding and tactile stimulation from the mother to the pups. Some evidence suggests that mother and infant can develop a cross-modal sensory recognition of their counterpart during this bonding process. Neurochemically, oxytocin in the neural system plays a pivotal role in each side of the mother-infant bonding process, although the mechanisms underlying bond formation in the brains of infants has not yet been clarified. Impairment of mother-infant bonding, that is, deprivation of social stimuli from the mother, strongly influences offspring sociality, including maternal behavior toward their own offspring in their adulthood, implying a non-genomic transmission of maternal environment, even in rodents. The comparative understanding of cognitive functions between mother and infants, and the biological mechanisms involved in mother-infant bonding may help us understand psychiatric disorders associated with mother-infant relationships.

  12. The coevolution of long-term pair bonds and cooperation.

    Science.gov (United States)

    Song, Z; Feldman, M W

    2013-05-01

    The evolution of social traits may not only depend on but also change the social structure of the population. In particular, the evolution of pairwise cooperation, such as biparental care, depends on the pair-matching distribution of the population, and the latter often emerges as a collective outcome of individual pair-bonding traits, which are also under selection. Here, we develop an analytical model and individual-based simulations to study the coevolution of long-term pair bonds and cooperation in parental care, where partners play a Snowdrift game in each breeding season. We illustrate that long-term pair bonds may coevolve with cooperation when bonding cost is below a threshold. As long-term pair bonds lead to assortative interactions through pair-matching dynamics, they may promote the prevalence of cooperation. In addition to the pay-off matrix of a single game, the evolutionarily stable equilibrium also depends on bonding cost and accidental divorce rate, and it is determined by a form of balancing selection because the benefit from pair-bond maintenance diminishes as the frequency of cooperators increases. Our findings highlight the importance of ecological factors affecting social bonding cost and stability in understanding the coevolution of social behaviour and social structures, which may lead to the diversity of biological social systems. PMID:23496797

  13. Agrobacterium tumefaciens T-DNA Integration and Gene Targeting in Arabidopsis thaliana Non-Homologous End-Joining Mutants

    Directory of Open Access Journals (Sweden)

    Qi Jia

    2012-01-01

    Full Text Available In order to study the role of AtKu70 and AtKu80 in Agrobacterium-mediated transformation and gene targeting, plant lines with a T-DNA insertion in AtKu80 or AtKu70 genes were functionally characterized. Such plant lines lacked both subunits, indicating that heterodimer formation between AtKu70 and AtKu80 is needed for the stability of the proteins. Homozygous mutants were phenotypically indistinguishable from wild-type plants and were fertile. However, they were hypersensitive to the genotoxic agent bleomycin, resulting in more DSBs as quantified in comet assays. They had lower end-joining efficiency, suggesting that NHEJ is a critical pathway for DSB repair in plants. Both Atku mutants and a previously isolated Atmre11 mutant were impaired in Agrobacterium T-DNA integration via floral dip transformation, indicating that AtKu70, AtKu80, and AtMre11 play an important role in T-DNA integration in Arabidopsis. The frequency of gene targeting was not significantly increased in the Atku80 and Atku70 mutants, but it was increased at least 10-fold in the Atmre11 mutant compared with the wild type.

  14. Effects of recycling and bonding agent application on bond strength of stainless steel orthodontic brackets

    OpenAIRE

    Bahnasi, Faisal-Ismail; Abd-Rahman, Aida-Nur-Ashikin; Abu-Hassan, Mohamed-Ibrahim

    2013-01-01

    Objectives: 1) to assess different methods of recycling orthodontic brackets, 2) to evaluate Shear Bond Strength (SBS) of (a) new, (b) recycled and (c) repeated recycled stainless steel brackets (i) with and (ii) without bracket base primer. Study Design: A total of 180 extracted human premolar teeth and 180 premolar stainless steel brackets were used. One hundred teeth and 100 brackets were divided into five groups of 20-teeth each. Four methods of recycling orthodontic brackets were used in...

  15. Exploitation of sulfonylurea resistance marker and non-homologous end joining mutants for functional analysis in Zymoseptoria tritici.

    Science.gov (United States)

    Sidhu, Y S; Cairns, T C; Chaudhari, Y K; Usher, J; Talbot, N J; Studholme, D J; Csukai, M; Haynes, K

    2015-06-01

    The lack of techniques for rapid assembly of gene deletion vectors, paucity of selectable marker genes available for genetic manipulation and low frequency of homologous recombination are major constraints in construction of gene deletion mutants in Zymoseptoria tritici. To address these issues, we have constructed ternary vectors for Agrobacterium tumefaciens mediated transformation of Z. tritici, which enable the single step assembly of multiple fragments via yeast recombinational cloning. The sulfonylurea resistance gene, which is a mutated allele of the Magnaporthe oryzae ILV2 gene, was established as a new dominant selectable marker for Z. tritici. To increase the frequency of homologous recombination, we have constructed Z. tritici strains deficient in the non-homologous end joining pathway of DNA double stranded break repair by inactivating the KU70 and KU80 genes. Targeted gene deletion frequency increased to more than 85% in both Z. tritici ku70 and ku80 null strains, compared to ⩽10% seen in the wild type parental strain IPO323. The in vitro growth and in planta pathogenicity of the Z. tritici ku70 and ku80 null strains were comparable to strain IPO323. Together these molecular tools add significantly to the platform available for genomic analysis through targeted gene deletion or promoter replacements and will facilitate large-scale functional characterization projects in Z. tritici. PMID:26092796

  16. Bond length variation in hydronitride molecules and nitride crystals

    Science.gov (United States)

    Buterakos, L. A.; Gibbs, G. V.; Boisen, M. B.

    1992-08-01

    Bond lengths calculated for the coordination polyhedra in hydronitride molecules match average values observed for XN bonds involving main group X-cations in nitride crystals to within ˜0.04 Å. As suggested for oxide and sulfide molecules and crystals, the forces that determine the average bond lengths recorded for coordinated polyhedra in hydronitride molecules and nitride crystals appear to be governed in large part by the atoms that comprise the polyhedra and those that induce local charge balance. The forces exerted on the coordinated polyhedra by other parts of the structure seem to play a small if not an insignificant role in governing bond length variations. Bonded radii for the nitride ion obtained from theoretical electron density maps calculated for the molecules increase linearly with bond length as observed for nitride crystals with the rock salt structure. Promolecule radii calculated for the molecules correlate with bonded and ionic radii, indicating that the electron density distributions in hydronitride molecules possess a significant atomic component, despite bond type.

  17. Ultrasonic Additive Manufacturing: Weld Optimization for Aluminum 6061, Development of Scarf Joints for Aluminum Sheet Metal, and Joining of High Strength Metals

    Science.gov (United States)

    Wolcott, Paul J.

    that plastic deformation occurs in the bulk of the foil, while previous studies have only identified microstructural changes to the bond interface region. A methodology for joining aluminum 6061 sheet material 0.076 in. (1.93 mm) thick is proposed based on iterative design studies which identified a scarf joint configuration as viable. Design of experiments studies indicate optimal properties can be achieved using a scarf joint angle of 10SO. Room temperature and elevated temperature tensile, and room temperature fatigue testing exhibit joint mechanical properties similar to solid, homogeneous material. Successful joints were achieved for Al/Ti, aluminum to steel, steel to aluminum, and steel to steel combinations. Mechanical characterization studies of Al/Ti combinations indicate that post-process heat treatments can significantly increase mechanical properties. Microstructural evaluations including electron back scatter diffraction show significant deformation within the softer aluminum layers. Investigations of Al/steel combinations indicate that mostly voidless interfaces occur and that plastic deformation is present in the steel layers only. Steel to steel combinations, while proven possible, require further work to enhance the consistency of the joints and improve the ability to build larger structures.

  18. 12 CFR 563.190 - Bonds for directors, officers, employees, and agents; form of and amount of bonds.

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Bonds for directors, officers, employees, and agents; form of and amount of bonds. 563.190 Section 563.190 Banks and Banking OFFICE OF THRIFT... provided by the insurance underwriter industry's standard forms, through the use of endorsements,...

  19. Increasing Database Performance through Optimizing Structure Query Language Join Statement

    Directory of Open Access Journals (Sweden)

    Ossama K. Muslih

    2010-01-01

    Full Text Available Problem statement: A join statement is a select statement with more than table in the FROM clause. A join predicate is a predicate in the WHERE clause that combines the columns of two of the tables in the join. Any database gives you the ability to join various tables together through different types of joins, resulting large number of rows to process. Query language can be used to join these tables and as it is well known query language should be declarative, so we can write alternative formulas to perform join statements. Different formulas provide variation in performance. Approach: This research presented a transparent middle layer between application interface front end and database back end. Results: The responsibilities of this layer were catching the SQL commands sent by application before reaching the database then examining these commands to see if they join more than one table, after that rewriting the SQL command taking into consideration the order of executing join predicates and none join predicates. This research focused on rewriting the SQL commands without application modification. Conclusion: Rewriting stage is the most complex stage because the system will restructure the SQL command with new syntax taking two things in its consideration, the first one was rewriting the command with better performance syntax after getting the help from recommendation dictionary, the second one was resulting the same data (output as previous old command.

  20. Bonding Energy and Growth Habit of Lithium Niobate Single Crystals

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    On the basis of crystallographic structure of lithium niobate (LN), the bonding energy was quantitatively calculated by the bond valence sum model, which was employed to investigate the crystal growth. A possible relationship between the crystal growth habit and chemical bonding energy of LN crystals are found. It is found that the higher the bond energy, the slower the growth rate, and the more important the plane. The analytical results indicate that (012) plane is the most influential face for the LN crystal growth, which consists well with the standard card (JCPDS Card: 20-0631) and our previous experimental observation. The current work shows that the chemical bond analysis of LN crystals allows us to predict its growth habit and thus to obtain the expected morphology during the spontaneous growth.

  1. THE POSITION OF THE RUSSIAN FEDERATION AND FEDERAL REPUBLIC OF GERMANY ON THE BALTIC REPUBLICS’ (LATVIA, LITHUANIA, ESTONIA JOINING THE EUROPEAN UNION

    Directory of Open Access Journals (Sweden)

    Mariya Dmitrievna Portnyagina

    2013-10-01

    Full Text Available Enlargement of the EU in 2004 was of great significance not only for the EU members, but for the Russian Federation as the candidates were former USSR republics and countries that had been under the influence of the USSR.  The purpose of this article is to uncover the attitude of Russian and German officials to Latvia, Lithuania and Estonia’s joining the EU. The study uses the methods of historicism and objectivity as its basis. A regional approach that describes the development of the region into global political process is used.The author proves that Russia has underestimated the consequence of Latvia, Lithuania and Estonia’s joining the EU. The Russian Federation made the hasty judgement that the Baltic countries’ joining the EU would automatically solve the bilateral problems in relations between Russia, Latvia, Lithiania and Estonia. Russian politicians failed to detect negative economic consequences, which the Baltic states’ joining the European Union brought about. The position of the German government was ambiguous. It was impacted by the obligations within its role as the ‘motor’ of European integration, but also had to consider the direct interests of the Federal Republic of Germany.  The German ruling coalition by morally supporting the intention of the Baltic Republics to join the EU delegated the role of an ‘advocate’ of newly independent republics to the northern European countries while taking the right to defend primarily national interests of the Federal Republic of Germany.The materials of the study can be used for further research of the history of the Baltic Region, in lectures and special courses.DOI: http://dx.doi.org/10.12731/2218-7405-2013-7-32

  2. Attachment and continuing bonds in bereavement

    Directory of Open Access Journals (Sweden)

    Anja Simonič

    2006-03-01

    Full Text Available The subject of this paper is the attachment in a relationship being one of the factors which co-form the grieving process after conjugal loss. In this integrative study about the grieving process after the loss of a partner due to sudden or expected death one or two years after the loss, the author determined that the relationship between partners represents an important indicator of the grieving process. Due to the sensitive nature of the process, the method used was a case study (seven participants were interviewed and a circular research process. The functioning of grieving persons in different areas of life was assessed with a semi-structured interview, specifically designed for this research, and with an adapted version of the Attachment Test, a part of Picture Test of Separation and Individuation (Žvelc and Žvelc, 2000. It was ascertained that particular contents in the grieving process are specifically connected with the type of relationship prior to death (ambivalent and closely connected/dependent relationship and the experiencing of the present position in relation to the deceased partner. Due to the fact that knowledge about possible maintenance/continuance of the bond between the partners has only recently become the locus of empirical research, the present study could not yet fully evaluate what kind of experience of current relationship position towards the partner contributes to healthy separation and individuation processes, i.e. grieving. Although the findings are limited to the specific context of each individual participant, the case study ascertained certain patterns in the relation between the grieving process and the attachment between partners, which indicates that there is a possibility of these in the wider population.

  3. New Product Development. Engineering and Commerce Students Join Forces with a Corporate Sponsor.

    Science.gov (United States)

    Audet, Josee; Pegna, Joseph

    2001-01-01

    Mechanical engineering and business student teams developed new products using a corporate sponsor's technology in a simulated business setting. Students learned about product development and venture start-up, and the sponsor gained new applications for its patented technology. (SK)

  4. The Comparative Analysis of Grain Trade Policies between China and South Korean after Joining the WTO

    Institute of Scientific and Technical Information of China (English)

    Li Xiaomei

    2006-01-01

    @@ In view of different grain trade structure and protectionism period, it is well known that China difficultly uses the technology and the green barriers to protect her domestic market as same skilled as Japan and European Union. At the same time, China often encounters above two barriers when it exports Japan and European Union.

  5. Sinopec and CNPC Join Hands to Keep Domestic oil Market Stable

    Institute of Scientific and Technical Information of China (English)

    Yang Xiangfeng

    2003-01-01

    @@ Sinopec and CNPC have recently issued an urgent circular on the joint efforts to stabilize the country's oil products market. The State Development and Reform Committee has lowered the retail median prices of gasoline and diesel by 290 yuan per ton and 260 yuan per ton respectively.

  6. Understanding Sarason's concepts of school cultures and change: joining a community in school improvement efforts.

    Science.gov (United States)

    Lorion, Raymond P

    2011-12-01

    This paper describes an evolving transformative partnership between a large comprehensive university, an urban school system and a predominantly African-American, low-income neighborhood. The partnership's originating intent was to apply an array of university, civic and local resources to improve the academic performance of a neighborhood's schools and the health, welfare and economic well-being of its residents. The extent to which that partnership would precipitate transactional (Sameroff and Fiese, Handbook of early childhood intervention, Cambridge University Press, Cambridge, pp. 119-149 in 1990) synergies among the partners was unanticipated; the long-term implications for each of the partners of such unfamiliar interactional processes remain unclear but are being systematically monitored over time. Evident at this point, however, it that a process has been initiated that has impacted how the university community, the local public school system, city government and the target neighborhood relate to each other, collaborate with each other and are changing each other. The pace of that process has varied over the years and challenged each partners' expectations and assumptions about the nature and consequences of their involvement. With time and perseverance, however, it appears that all are moving toward a sense of mutual learning and trust and toward extending to each other the benefit of the doubt. This paper discusses the evolution of that process and its implications for university-school-community collaborations. PMID:20857327

  7. Joining characteristics of titanium-based orthodontic wires connected by laser and electrical welding methods.

    Science.gov (United States)

    Matsunaga, Junko; Watanabe, Ikuya; Nakao, Noriko; Watanabe, Etsuko; Elshahawy, Waleed; Yoshida, Noriaki

    2015-01-01

    This study investigated the possibility of electrical and laser welding to connect titanium-based alloy (beta-titanium and nickel-titanium) wires and stainless-steel or cobalt-chromium alloy wires for fabrication of combination arch-wires. Four kinds of straight orthodontic rectangular wires (0.017 × 0.025 inch) were used: stainless-steel (S-S), cobalt-chromium (Co-Cr), beta-titanium alloy (β-Ti), and nickel-titanium (Ni-Ti). Homogeneous and heterogeneous end-to-end joints (15 mm long each) were made by electrical welding and laser welding. Non-welded wires (30 mm long) were also used as a control. Maximum loads at fracture (N) and elongation (%) were measured by conducting tensile test. The data (n = 10) were statistically analyzed using analysis of variance/Tukey test (P < 0.05).The S-S/S-S and Co-Cr/Co-Cr specimens showed significantly higher values of the maximum load (ML) at fracture and elongation (EL) than those of the Ni-Ti/Ni-Ti and β-Ti/β-Ti specimens for electrical welding and those of the S-S/S-S and Co-Cr/Co-Cr specimens welded by laser. On the other hand, the laser-welded Ni-Ti/Ni-Ti and β-Ti/β-Ti specimens exhibited higher values of the ML and EL compared to those of the corresponding specimens welded by electrical method. In the heterogeneously welded combinations, the electrically welded Ni-Ti/S-S, β-Ti/S-S and β-Ti/Co-Cr specimens showed significantly (P < 0.05) higher ML and EL than those of the corresponding specimens welded by laser. Electrical welding exhibited the higher values of maximum load at fracture and elongation for heterogeneously welded combinations than laser-welding. PMID:25595723

  8. Solid cartridge for a pulse weld forming electrode and method of joining tubular members

    Energy Technology Data Exchange (ETDEWEB)

    Bonnen, John Joseph Francis; Golovashchenko, Sergey Fedorovich; Mamutov, Alexander; Maison, Lloyd Douglas; Dawson, Scott Alwyn; deVries, James

    2016-02-23

    A cartridge assembly is disclosed for a pulse welding a first tube supported on a mandrel to a second tube. An outer tool is assembled over the second tube and a stored charge is discharged in the cartridge assembly. The cartridge comprises an annular conductor and a solid casing enveloping the conductor. The stored charge is electrically connected to the conductor and discharged through the conductor to compress the second tube and pulse weld the second tube to the first tube.

  9. The Boy from Fez: A tale of five charities, and the global community, joining hands.

    Science.gov (United States)

    Zniber, Layla; Rogers, Maria; Bhat, Akhlaque Nabi; Sallehuddin, Ahmad; Yacoub, Lisa

    2013-01-01

    A case study in global cooperation between multiple charities and cardiac centers helped to save a 8-year-old Moroccan boy suffering a case of Laubry-Pezzi syndrome with severe aortic regurgitation and ventricular septal defect. His recuperation was aided by the support of communities in both Morocco and Qatar. PMID:24689013

  10. World Crisis as "Teachable Moment": Joining Global Issues, International Law, and the Internet in the Classroom.

    Science.gov (United States)

    Leary, John E., Jr.

    2000-01-01

    Describes a mock judicial proceeding that incorporated computers in the classroom and questioned international law. Explains that students were divided into interested parties in the Kosovo conflict (NATO members, the Yugoslavian government, Kosovo Albanians, Russians, and Chinese), a delegation of human-rights groups, and a panel of judges. (CMK)

  11. Robert Beichner joins university as American Council of Education Fellow and visiting professor of physics

    OpenAIRE

    Owczarski, Mark

    2010-01-01

    Robert Beichner, Alumni Distinguished Professor of Physics and director of the Science, Technology, Engineering and Mathematics Education Initiative at North Carolina State University, will spend the fall semester as the American Council of Education Fellow and visiting professor of physics in the College of Science.

  12. Joined-up food policy? The trials of governance, public policy and the food system

    OpenAIRE

    Barling, D.; Lang, T; Caraher, M.

    2002-01-01

    To address the policy malfunctions of the recent past and present, UK food policy needs to link policy areas that in the past have been dealt with in a disparate manner, and to draw on a new ecological public health approach. This will need a shift within the dominant trade liberalization–national economic competitiveness paradigm that currently informs UK food policy, and the international levels of the EU and the WTO trade rules, and grants the large corporate players in the food system a f...

  13. Astronomy EPO and the 2012 Hysteria: Your Personal Guide to Joining the Battle

    Science.gov (United States)

    Larsen, K.

    2011-09-01

    Individual members of the astronomical community have, in recent months, begun to take up the charge and rally against the vast army of pseudoscience, superstition, and snake oil salesmen that is the 2012 phenomenon. EPO specialists and facilities are in a unique and vitally important position to move to the forefront of this battle, given our long-standing dedication to improving the astronomical education of the general public. This poster documents concrete ways in which the astronomy EPO community can (and should) combat the 2012 movement.

  14. Modeling the joined performance of PanSTARRS1 and PanSTARRS2 telescopes

    Science.gov (United States)

    Lilly (Schunova), Eva; Wainscoat, Richard J.; Weryk, Robert J.

    2016-10-01

    We have performed detailed simulations of the 1st and the 2nd telescope of the Panoramatic Survey Telescope and Rapid response System (PanSTARRS, Morgan et al. 2012, SPIE Conference Series, Vol. 8444; Chambers et al. 2007, Bulletin of the American Astronomical Society, Vol. 39, #142.06) in order to assess their combined performance and to optimize survey strategy for discovery and follow-up observations of near-Earth asteroids (NEAs).PanSTARRS1 (PS1) is situated on the summit of Haleakala, Maui (observatory code F51) and has been operated by the University of Hawaii since the spring of 2010. PS1 has a 1.8 m diameter primary mirror with an ~7 deg2 field of view and can survey ~900 deg2/night for moving objects.PS2 is located adjacent to PS1, and is similar, but benefits from many improvements coming from our experience with PS1. PS2 will be operational very soon.We will show how the best and the worst case scenarios of observing conditions (i.e. regarding the weather and the position of the Galactic plane) affect the NEA detection efficiency during a 1-month long survey for several PS1 and PS2 observing and follow-up strategies.

  15. Joining techniques development for neutron irradiation tests and post irradiation examinations in JMTR-HL

    International Nuclear Information System (INIS)

    The hot laboratory (JMTR-HL) associated with the JMTR (Japan Materials Testing Reactor) was founded to examine the material and fuel specimens irradiated mainly in the JMTR. Through the post-irradiation examinations (PIEs) have been developed and performed, the JMTR-HL contributes not only to research of materials for light water reactors, fast reactors, high temperature gas reactor, and fusion reactor, but also to production of domestic industrial radio isotopes like 192Ir. As the part of PIE technology development, several kinds of welding techniques have been systematically developed. These research and development of welding techniques such as circumference and sealing for irradiation capsules and rewelding with irradiated materials were implemented under the remote-controlled conditions in the hot cells. These techniques are very indispensable for the neutron irradiation tests and PIEs to be conducted in the JMTR. (author)

  16. Carlsberg Circular Community: when a company and its suppliers join forces to implement eco-innovation

    DEFF Research Database (Denmark)

    Niero, Monia; Boas, S.H.; Olsen, Stig Irving

    2014-01-01

    value for the stakeholders across the value chain and provide a positive impact for the users, then a broader approach oriented towards product quality and innovation was selected, i.e. the Cradle to Cradle® (C2C) design framework. C2C aims indeed at increasing the positive footprint of products...... and systems maximizing the benefit to ecological and economical systems, rather than as re-designing ingredients or additives in a material so they improve the quality of recycling. From a company point of view, LCA and C2C can be seen as complementary approaches in the development of sustainable...... and innovative solutions for beer packaging. However, from a value chain perspective C2C-inspired initiatives are potentially more beneficial. We will illustrate the challenges and opportunities emerging from the Carlsberg Circular Community experience in developing products that are optimized for re...

  17. Join the Revolution: How Montessori for Aging and Dementia can Change Long-Term Care Culture.

    Science.gov (United States)

    Bourgeois, Michelle S; Brush, Jennifer; Elliot, Gail; Kelly, Anne

    2015-08-01

    Efforts to improve the quality of life of persons with dementia in long-term care through the implementation of various approaches to person-centered care have been underway for the past two decades. Studies have yielded conflicting reports evaluating the evidence for these approaches. The purpose of this article is to outline the findings of several systematic reviews of this literature, highlighting the areas of improvement needs, and to describe a new person-centered care model, DementiAbility Methods: The Montessori Way. This model focuses on the abilities, needs, interests, and strengths of the person and creating worthwhile and meaningful roles, routines, and activities for the person within a supportive physical environment. This is accomplished through gaining the commitment of the facility's leaders, training staff, and monitoring program implementation. The potential for a culture change in long-term care environments is dependent on the development and rigorous evaluation of person-centered care approaches. PMID:26190512

  18. Highlights from e-EPS: EPS and EuChems are joining forces

    CERN Multimedia

    2013-01-01

    e-EPS News is an addition to the CERN Bulletin line-up, showcasing articles from e-EPS – the European Physical Society newsletter – as part of a collaboration between the two publications.   On the occasion of the EPS Council 2013 in Strasbourg, a memorandum of understanding was signed between the European Association for Chemical and Molecular Societies (EuCheMS) and the European Physical Society (EPS) by presidents Ulrich Schubert and Luisa Cifarelli. EuCheMS and EPS share many objectives, such as community building, scientific excellence, communication and representation of their respective members to European policy makers. The two societies recognise that issues in many fields such as education, publication, support for basic sciences and frontier research are similar in their respective disciplines. They wish to combine efforts in developing and presenting common standpoints to their mutual benefit as European representatives in chemistry ...

  19. Three High-Tech High Seniors Join the Alia Expedition to Samoa: Science and Science Education

    Science.gov (United States)

    English, B.; Delaney, R.; Staudigel, D.; Staudigel, H.; Koppers, A.; Hart, S.

    2005-12-01

    Three high school seniors from High Tech High (HTH) participated in the ALIA expedition that explored the Samoan hot spot track through seafloor mapping, rock sampling and the study of the water column above an active submarine volcano. The primary responsibility of the HTH participants focused on outreach and education, but they also were substantively involved in all scientific aspects of the cruise. Education and outreach activities included: maintaining the cruise website,the creation of ERESE digital library resources for earth science education, live video-conferences with students half a world away in San Diego, and offering tours of the Research Vessel Kilo Moana during an open house event organized with the Samoa Department of Eduation. At this occasion, the HTH seniors shared experiences and knowledge with the visiting Samoan elementary and high school students. Science involvement of the high school seniors included deck and laboratory work, by assisting with dredging, piston coring, rock cataloguing, casting CTDs, and computer programming. Three major computer programming efforts by the HTH seniors substantively supported the outreach activities and the science operations during ALIA. (1) The development of "CustomHTMLExport", a utility that allows for the export of photographs and their metadata into web pages and digital library collection. (2) The "CruiseWatch" featureson the ALIA website (http://earthref.org/ERESE/projects/ALIA/) that displays in near - real time key shipboard data such as the location on a map, geographic coordinates, ship speed, direction and wind speed and dredging data. (3) A dredge location simulator to predict the location of the dredge with respect to the ship and the seafloor which was made necessary for the safety of dredging due to the failure of pingers that normally are used to provide critical data for the location of the dredge with respect to the seafloor. The dredge location model is based a fluid dynamics approach

  20. Optimizing relational algebra operations using discrimination-based joins and lazy products

    DEFF Research Database (Denmark)

    Henglein, Fritz

    that discriminators can be constructed generically (by structural recursion on equivalence expressions), purely func- tionally, and efficiently (worst-case linear time). The array-based basic multiset discrimination algorithm of Cai and Paige (1995) provides a base discriminator that is both asymptotically and prac......- tically efficient. In contrast to hashing, discrimination is fully ab- stract (only depends on which equivalences hold on its inputs), and in contrast to comparison-based sorting, it does not require an or- dering relation on its inputs. In particular, it is applicable to ref- erences (pointers......). Furthermore, it has better asymptotic computa- tional complexity than both sorting and hashing. We represent cross-products and unions lazily (symbolically) as formal products of the argument sets (relations). This allows the selection operation to recognize on the fly whenever it is applied to a cross...

  1. Local air quality management and climate change: tools for joined up policy

    OpenAIRE

    Ireland, Matthew P.

    2003-01-01

    All tiers of UK Government are required to include a range of environmental objectives in developing land use and transportation plans. The current trend towards regionalisation of governance brings with it uncertainty and debate. Part of this debate must include determination of the optimum scale for implementing land use and transportation plans to incorporate environmental objectives. This thesis is the result of developing tools to assist in this debate, using the environmental objectives...

  2. Scientists and stakeholders: can two separate worlds be joined for sustainable water management?

    OpenAIRE

    Varanda, Marta Pedro; Bento, Sofia

    2013-01-01

    According to the International Council for Science, science should be developed for the benefit of all. In face of complex environmental problems and of a need for the sustainable management of water, answers are increasingly requested from science. A science that can face such challenge must be constructed in cooperation with policy makers and society (hence enlarging the traditional scientific sphere), and its product must be effectively linked to policy. However, these new forms of science...

  3. Considerations of metal joining processes for space fabrication, construction and repair

    Science.gov (United States)

    Russell, C.; Poorman, R.; Jones, C.; Nunes, A.; Hoffman, D.

    A comprehensive evaluation is conducted of candidate processes for metalworking in orbital (vacuum-microgravity) conditions. Attention is given to electron-beam welding, brazing, gas-tungsten arc welding, laser welding, plasma arc welding, and gas-metal arc welding. It is established that several of these processes will be required to cover all foreseeable requirements. Microgravity effects are considered minor, and efforts are being concentrated on problems associated with vacuum conditions and with process-operator safety.

  4. Proceedings of US-Japan workshop on new generation experiments and reactors (joined by EC)

    International Nuclear Information System (INIS)

    The workshop, titled 'New Generation Experiments and Reactors', was held at Plasma Physics Laboratory, Kyoto University from 25 to 28 July 1988. The purpose of the meeting was to review the latest achievements and status of stellarator/heliotron new generation experiments as well as the prospects for stellarator/heliotron fusion reactors on the occasion when the New Large Helical System of MOE in Japan is being realized. The reports on the New Large Helical System of MOE cover an overview, physics issues, design, MHD studies, transport code results and bootstrap current, particle orbit studies, divertor studies, NBI heating, analysis of wave heating, heating system, diagnostics, and SC coil technology. The reports on ATF II cover an overview, physics studies strategy, status of physics studies, engineering issues, perspective of helical systems, issues for next-generation experiments and relationship to the Univ. of Wisconsin Program, and issues for next-generation experiments and relation to Auburn Program. Other reports address recent studies of present devices, studies related with WVIIX, and reactor studies. (N.K.)

  5. SOCIAL NETWORKING: REASONS TO JOIN AND THINGS DONE BY THE ROMANIAN CONSUMERS - AN EXPLORATORY ASSESSMENT

    Directory of Open Access Journals (Sweden)

    Pantea Carmen

    2009-05-01

    Full Text Available Initially developed in order to allow human interactions in the virtual environment as online communities of people having common concerns and willing to share and exchange ideas, today social networks represent one of the online marketing tools with the

  6. Phase transformation and deformation behavior of NiTi-Nb eutectic joined NiTi wires.

    Science.gov (United States)

    Wang, Liqiang; Wang, Cong; Zhang, Lai-Chang; Chen, Liangyu; Lu, Weijie; Zhang, Di

    2016-04-06

    NiTi wires were brazed together via eutectic reaction between NiTi and Nb powder deposited at the wire contact region. Phase transformation and deformation behavior of the NiTi-Nb eutectic microstructure were investigated using transmission electron microscopy (TEM) and cyclic loading-unloading tests. Results show that R phase and B19' martensite transformation are induced by plastic deformation. R phase transformation, which significantly contributes to superelasticity, preferentially occurs at the interfaces between NiTi and eutectic region. Round-shaped Nb-rich phase with rod-like and lamellar-type eutectics are observed in eutectic regions. These phases appear to affect the deformation behavior of the brazed NiTi-Nb region via five distinct stages in stress-strain curves: (I) R phase reorientation, (II) R phase transformation from parent phase, (III) elastic deformation of reoriented martensite accompanied by the plastic deformation of Nb-rich phase and lamellar NiTi-Nb eutectic, (IV) B19' martensitic transformation, and (V) plastic deformation of the specimen.

  7. Phase transformation and deformation behavior of NiTi-Nb eutectic joined NiTi wires.

    Science.gov (United States)

    Wang, Liqiang; Wang, Cong; Zhang, Lai-Chang; Chen, Liangyu; Lu, Weijie; Zhang, Di

    2016-01-01

    NiTi wires were brazed together via eutectic reaction between NiTi and Nb powder deposited at the wire contact region. Phase transformation and deformation behavior of the NiTi-Nb eutectic microstructure were investigated using transmission electron microscopy (TEM) and cyclic loading-unloading tests. Results show that R phase and B19' martensite transformation are induced by plastic deformation. R phase transformation, which significantly contributes to superelasticity, preferentially occurs at the interfaces between NiTi and eutectic region. Round-shaped Nb-rich phase with rod-like and lamellar-type eutectics are observed in eutectic regions. These phases appear to affect the deformation behavior of the brazed NiTi-Nb region via five distinct stages in stress-strain curves: (I) R phase reorientation, (II) R phase transformation from parent phase, (III) elastic deformation of reoriented martensite accompanied by the plastic deformation of Nb-rich phase and lamellar NiTi-Nb eutectic, (IV) B19' martensitic transformation, and (V) plastic deformation of the specimen. PMID:27049025

  8. Getting at the Join: Integrating Astrophysics and Astronomy in Computer Science Coursework

    Science.gov (United States)

    Austin, S. A.; Zirbel, E. L.; Johnson, L. P.

    2001-05-01

    Scientific computing in the traditional Computer Science curriculum typically involves the application of methods across the disciplines of both Engineering and the Physical Sciences. Typical applications detach methods and computational techniques from the underlying science. As part of a OSS-funded educational initiative for Minority Institutions, we are exploring the integration and applications of Astronomy as part of an experimental project course. The exploratory course integrates fundamental background material in Astronomy together with computational methods used to generate graphical simulations of underlying physical concepts. Students participating in the course are advanced Computer Science majors with Physics minors interested in combining the two areas. The course is led by faculty in Astrophysics and Computer Science. Examples of some of the student' projects will be provided with some discussion of the challenges and opportunities posed by this interdisciplinary approach. [Supported by NASA/OSS

  9. LHCb: Optimising query execution time in LHCb Bookkeeping System using partition pruning and partition wise joins

    CERN Multimedia

    Mathe, Z

    2013-01-01

    The LHCb experiment produces a huge amount of data which has associated metadata such as run number, data taking condition (detector status when the data was taken), simulation condition, etc. The data are stored in files, replicated on the Computing Grid around the world. The LHCb Bookkeeping System provides methods for retrieving datasets based on their metadata. The metadata is stored in a hybrid database model, which is a mixture of Relational and Hierarchical database models and is based on the Oracle Relational Database Management System (RDBMS). The database access has to be reliable and fast. In order to achieve a high timing performance, the tables are partitioned and the queries are executed in parallel. When we store large amounts of data the partition pruning is essential for database performance, because it reduces the amount of data retrieved from the disk and optimises the resource utilisation. This research presented here is focusing on the extended composite partitioning strategy such as rang...

  10. Dividends Sharing Convertible Bonds Pricing and Numerical Evaluation

    Directory of Open Access Journals (Sweden)

    Xu Guo

    2013-01-01

    Full Text Available The convertible bond is becoming one of the most important financial instruments for the company to raise capital fund since it was first issued by American New York Erie Company in 1843. In this paper, it is the first time to study the pricing problem for convertible bond whose underlying stocks pay dividends via the reflected backward stochastic differential equations. Associating the solutions of reflected BSDEs with the obstacle problems for nonlinear parabolic PDEs, we establish the pricing formulas for convertible bonds with continuous and discrete dividends by means of the viscosity solutions for some PDEs. Besides, we also derive the price of convertible bonds with higher borrowing rate which is realistic in the financial market. Then the numerical evaluations are provided by the radial basis functions method. Moreover, we discuss the influence of dividends paying as well as higher borrowing rate on the convertible bond price at last.

  11. Joining direct and indirect inverse calibration methods to characterize karst, coastal aquifers

    Science.gov (United States)

    De Filippis, Giovanna; Foglia, Laura; Giudici, Mauro; Mehl, Steffen; Margiotta, Stefano; Negri, Sergio

    2016-04-01

    Parameter estimation is extremely relevant for accurate simulation of groundwater flow. Parameter values for models of large-scale catchments are usually derived from a limited set of field observations, which can rarely be obtained in a straightforward way from field tests or laboratory measurements on samples, due to a number of factors, including measurement errors and inadequate sampling density. Indeed, a wide gap exists between the local scale, at which most of the observations are taken, and the regional or basin scale, at which the planning and management decisions are usually made. For this reason, the use of geologic information and field data is generally made by zoning the parameter fields. However, pure zoning does not perform well in the case of fairly complex aquifers and this is particularly true for karst aquifers. In fact, the support of the hydraulic conductivity measured in the field is normally much smaller than the cell size of the numerical model, so it should be upscaled to a scale consistent with that of the numerical model discretization. Automatic inverse calibration is a valuable procedure to identify model parameter values by conditioning on observed, available data, limiting the subjective evaluations introduced with the trial-and-error technique. Many approaches have been proposed to solve the inverse problem. Generally speaking, inverse methods fall into two groups: direct and indirect methods. Direct methods allow determination of hydraulic conductivities from the groundwater flow equations which relate the conductivity and head fields. Indirect methods, instead, can handle any type of parameters, independently from the mathematical equations that govern the process, and condition parameter values and model construction on measurements of model output quantities, compared with the available observation data, through the minimization of an objective function. Both approaches have pros and cons, depending also on model complexity. For

  12. Fork-Join program response time on multiprocessors with exchangeable join

    Institute of Scientific and Technical Information of China (English)

    WANG Yong-cai; ZHAO Qian-chuan; ZHENG Da-zhong

    2006-01-01

    The Fork-Join program consisting of K parallel tasks is a useful model for a large number of computing applications.When the parallel processor has multi-channels, later tasks may finish execution earlier than their earlier tasks and may join with tasks from other programs. This phenomenon is called exchangeable join (EJ), which introduces correlation to the task's service time. In this work, we investigate the response time of multiprocessor systems with EJ with a new approach. We analyze two aspects of this kind of systems: exchangeable join (EJ) and the capacity constraint (CC). We prove that the system response time can be effectively reduced by EJ, while the reduced amount is constrained by the capacity of the multiprocessor. An upper bound model is constructed based on this analysis and a quick estimation algorithm is proposed. The approximation formula is verified by extensive simulation results, which show that the relative error of approximation is less than 5%.

  13. Pseudomyrmex ants and Acacia host plants join efforts to protect their mutualism from microbial threats

    OpenAIRE

    González-Teuber, Marcia; Heil, Martin

    2010-01-01

    Plants express numerous ‘pathogenesis-related’ (PR) proteins to defend themselves against pathogen infection. We recently discovered that PR-proteins such as chitinases, glucanases, peroxidases and thaumatin-like proteins are also functioning in the protection of extra-floral nectar (EFN) of Mexican Acacia myrmecophytes. These plants produce EFN, cellular food bodies and nesting space to house defending ant species of the genus Pseudomyrmex. More than 50 PR-proteins were discovered in this EF...

  14. Joining mechanisms and mechanical properties of PA composites obtained by selective laser sintering

    OpenAIRE

    Iuliano, Luca

    2012-01-01

    Additive manufacturing is today a viable industrial solution alongside traditional processes. Techniques like selective laser sintering (SLS) address the issues of digital production and mass customization in a variety of materials. Composite parts can be obtained with specific functional and mechanical properties. Building orientation during additive manufacturing often causes anisotropy of parts' properties that is still unspecified in technical information. The purpose of this paper is to ...

  15. Theoretical and practical investigation into sustainable metal joining process for the automotive industry

    International Nuclear Information System (INIS)

    Currently there are about 4300 weld points on the average steel vehicle. Errors and problems due to tip damage and wear can cause great losses due to production line downtime. Current industrial monitoring systems check the quality of the nugget after processing 15 cars average once every two weeks. The nuggets are examined off line using a destructive process, which takes approximately 10 days to complete causing a long delay in the production process. In this paper a simulation results using software package, SORPAS, will be presented to determined the sustainability factors in spot welding process including Voltage, Current, Force, Water cooling rates, Material thicknesses and usage. The experimental results of various spot welding processes will be investigated and reported. The correlation of experimental results shows that SORPAS simulations can be used as an off line measurement to reduce factory energy usage. This paper also provides an overview of electrode current selection and its variance over the lifetime of the electrode tip, and describes the proposed analysis system for the selection of welding parameters for the spot welding process, as the electrode tip wears.

  16. Generation and reactivation of T-cell receptor A joining region pseudogenes in primates

    Energy Technology Data Exchange (ETDEWEB)

    Thiel, C.; Lanchbury, J.S. [Guy`s Hospital, London (United Kingdom); Otting, N. [Biomedical Primate Research Centre, Rijswijk (Netherlands)] [and others

    1996-06-01

    Tandemly duplicated T-cell receptor (Tcr) AJ (J{alpha}) segments contribute significantly to TCRA chain junctional region diversity in mammals. Since only limited data exists on TCRA diversity in nonhuman primates, we examined the TCRAJ regions of 37 chimpanzee and 71 rhesus macaque TCRA cDNA clones derived from inverse polymerase chain reaction on peripheral blood mononuclear cell cDNA of healthy animals. Twenty-five different TCRAJ regions were characterized in the chimpanzee and 36 in the rhesus macaque. Each bears a close structural relationship to an equivalent human TCRAJ region. Conserved amino acid motifs are shared between all three species. There are indications that differences between nonhuman primates and humans exist in the generation of TCRAJ pseudogenes. The nucleotide and amino acid sequences of the various characterized TCRAJ of each species are reported and we compare our results to the available information on human genomic sequences. Although we provide evidence of dynamic processes modifying TCRAJ segments during primate evolution, their repertoire and primary structure appears to be relatively conserved. 21 refs., 2 figs.

  17. High-Cost Patients Had Substantial Rates Of Leaving Medicare Advantage And Joining Traditional Medicare.

    Science.gov (United States)

    Rahman, Momotazur; Keohane, Laura; Trivedi, Amal N; Mor, Vincent

    2015-10-01

    Medicare Advantage payment regulations include risk-adjusted capitated reimbursement, which was implemented to discourage favorable risk selection and encourage the retention of members who incur high costs. However, the extent to which risk-adjusted capitation has succeeded is not clear, especially for members using high-cost services not previously considered in assessments of risk selection. We examined the rates at which participants who used three high-cost services switched between Medicare Advantage and traditional Medicare. We found that the switching rate from 2010 to 2011 away from Medicare Advantage and to traditional Medicare exceeded the switching rate in the opposite direction for participants who used long-term nursing home care (17 percent versus 3 percent), short-term nursing home care (9 percent versus 4 percent), and home health care (8 percent versus 3 percent). These results were magnified among people who were enrolled in both Medicare and Medicaid. Our findings raise questions about the role of Medicare Advantage plans in serving high-cost patients with complex care needs, who account for a disproportionately high amount of total health care spending.

  18. Synthesis and Pharmacological Evaluation of Modified Adenosines Joined to Mono-Functional Platinum Moieties

    Directory of Open Access Journals (Sweden)

    Stefano D'Errico

    2014-07-01

    Full Text Available The synthesis of four novel platinum complexes, bearing N6-(6-amino-hexyladenosine or a 1,6-di(adenosin-N6-yl-hexane respectively, as ligands of mono-functional cisplatin or monochloro(ethylendiamineplatinum(II, is reported. The chemistry exploits the high affinity of the charged platinum centres towards the N7 position of the adenosine base system and a primary amine of an alkyl chain installed on the C6 position of the purine. The cytotoxic behaviour of the synthesized complexes has been studied in A549 adenocarcinomic human alveolar basal epithelial and MCF7 human breast adenocarcinomic cancer cell lines, in order to investigate their effects on cell viability and proliferation.

  19. Terahertz wave behaviours in ceramic and metal structures fabricated by spatial joining of micro-stereolithography

    Energy Technology Data Exchange (ETDEWEB)

    Kirihara, S; Niki, T; Kaneko, M [Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka Ibaraki, 567-0047 Osaka (Japan)], E-mail: kirihara@jwri.osaka-u.ac.jp

    2009-05-01

    We have newly developed micro-stereolithography system to realize freeform fabrication of micrometer order 3D metal structures. In this process, the photo-sensitive resin paste mixed with nanometer sized ceramic and metal particles was spread on a glass substrate with 10 {mu}m in layer thickness by using a mechanical knife edge, and two-dimensional images of UV ray were exposed using DMD (Digital Micro-mirror Device) with 2 {mu}m in part accuracy. Through the layer by layer stacking process, micrometer order three-dimensional objects were formed. Dense metal structures could be obtained by dewaxing and successive sintering of the formed objects. In our recent investigation, micro photonic crystals with lattice structures of alumina or pure copper were fabricated in order to control electromagnetic wave propagation in a terahertz (THz) frequency range. The micro photonic crystals with a diamond structure perfectly reflected the THz wave by Bragg diffraction.

  20. Algerian Economy and Multilateral Trading System: Why Is It So Hard to Join the WTO

    Directory of Open Access Journals (Sweden)

    Khayreddine Belaaze

    2014-08-01

    Full Text Available The main purpose of this paper is to provide a overview on different stages of the negotiations with World Trade Organization, since 1987 date of submission the application for accession, Algeria still trying to snatch accession card with minimum cost, where it tries to provide small guarantees, but some WTO members raises reservations over some issues like aspects related to investment, for example: the Rule of 49/51, and domestic component, prevention of exporting, besides the agricultural issue which takes advantage of domestic subsidies and exporting subsides, also services industry knows low degree of openness, especially In some sensitive areas such as financial services, telecommunications.

  1. How Does Auditory Training Work? Joined-Up Thinking and Listening.

    Science.gov (United States)

    Ferguson, Melanie; Henshaw, Helen

    2015-11-01

    Auditory training aims to compensate for degradation in the auditory signal and is offered as an intervention to help alleviate the most common complaint in people with hearing loss, understanding speech in a background noise. Yet there remain many unanswered questions. This article reviews some of the key pieces of evidence that assess the evidence for whether, and how, auditory training benefits adults with hearing loss. The evidence supports that improvements occur on the trained task; however, transfer of that learning to generalized real-world benefit is much less robust. For more than a decade, there has been an increasing awareness of the role that cognition plays in listening. But more recently in the auditory training literature, there has been an increased focus on assessing how cognitive performance relevant for listening may improve with training. We argue that this is specifically the case for measures that index executive processes, such as monitoring, attention switching, and updating of working memory, all of which are required for successful listening and communication in challenging or adverse listening conditions. We propose combined auditory-cognitive training approaches, where training interventions develop cognition embedded within auditory tasks, which are most likely to offer generalized benefits to the real-world listening abilities of people with hearing loss. PMID:27587911

  2. Joining and leaving sex work: experiences of women in Kigali, Rwanda

    NARCIS (Netherlands)

    M.C. Ingabire; K. Mitchell; N. Veldhuijzen; M.M. Umulisa; J. Nyinawabega; E. Kesteleyn; M. van Steijn; J. van de Wijgert; R. Pool

    2012-01-01

    Although sex work can bring significant economic benefit there are serious downsides, not least vulnerability to adverse sexual health outcomes. Focus-groups discussions and in-depth interviews were conducted with 70 female sex workers to explore the context in which they started sex work, their mot

  3. In College and in Recovery: Reasons for Joining a Collegiate Recovery Program

    Science.gov (United States)

    Laudet, Alexandre B.; Harris, Kitty; Kimball, Thomas; Winters, Ken C.; Moberg, D. Paul

    2016-01-01

    Objective: Collegiate Recovery Programs (CRPs), a campus-based peer support model for students recovering from substance abuse problems, grew exponentially in the past decade, yet remain unexplored. Methods: This mixed-methods study examines students' reasons for CRP enrollment to guide academic institutions and referral sources. Students (N =…

  4. Organizational Communication and Knowledge Management - Separated at Birth yet Joined at the Hip

    DEFF Research Database (Denmark)

    Kastberg, Peter

    2011-01-01

    of the conceptualizations of ‘organization’, ‘communication’ and ‘Knowledge Management’ respectively and view them – in their synthesis – as an expression of a new practice of communicating knowledge within the field of internal corporate communication. The presentation ends with a case study dealing with pertinent issues...... of this new practice in corporations. Key words: Internal corporate communication, Knowledge Management, triple helix of disciplinary trajectories......There is an emerging tendency – at least in continental Europe – that the corporate communication function of larger companies tends to enter into some kind of symbiosis with the companies’ Knowledge Management function. This should come as no surprise to neither the researcher nor the practitioner...

  5. Mechanical Behaviour and Microstructure of Aluminum-Steel Sheets Joined by FSSW

    OpenAIRE

    Bozzi, S.; Etter, A.L.; Baudin, T.; Robineau, A.; Goussain, J. C.

    2008-01-01

    At the prospect of a lightening of the automobile structures, welded spots have been realized on a stacking of two sheets (a 6008 aluminum alloy on steel) Friction Stir Spot welding (FSSW). Different process parameters have been tested, but only the influence of the dwell time will be described in the present paper. The dwell time corresponds to the time during which the probe stays in rotation at its bottom location before extracting. A study of the microstructures and textures associated to...

  6. The Female FTSE Board Report 2009: Norway and Spain join our census to benchmark corporate boards

    OpenAIRE

    Sealy, Ruth; Vinnicombe, Susan; Doldor, Elena

    2009-01-01

    2009 marks our eleventh annual report with a small incremental increase in the percentage of women on boards. Overall, there are 12.2% women directors on the FTSE 100 boards. There is a discouraging decline in the number of companies with female executive directors to 15 (from 16). Also disappointing is a decline in the number of boards with multiple women directors to 37 (from 39). In addition there is a decline in the overall number of companies with women on boards, and o...

  7. Jiangxi Copper and Yates Joined Hands in High-Grade Copper Foil Project Construction

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    <正> The construction of a large-scale copper foilproject recently started in the High-Tech De-velopment Zone of Nanchang,the capital ofJiangxi Province.This new copper foil factory,with a designed annual production capacity of6,000 tons of high-grade copper foil,is a jointventure project between Jiangxi Copper Group,the No.1 copper producer in China,and YatesInc.,a leading US copper product company andthe world’s first electrical circuit board maker.

  8. GRB 991216 Joins the Jet Set Discovery and Monitoring of its Optical Afterglow

    CERN Document Server

    Halpern, J P; Mirabal, N; Kassin, S; Thorstensen, J R; Keel, W C; Diercks, A H; Bloom, J S; Harrison, F; Mattox, J R; Eracleous, M

    2000-01-01

    The optical light curve of the energetic gamma-ray burst GRB 991216 is consistent with jet-like behavior in which a power-law decay steepens from t**(-1.22 +/- 0.04) at early times to t**(-1.53 +/- 0.05) in a gradual transition at around 2 d. The derivation of the late-time decay slope takes into account the constant contribution of a host or intervening galaxy which was measured 110 d after the event at R = 24.56 +/- 0.14, although the light curve deviates from a single power law whether or not a constant term is included. The early-time spectral energy distribution of the afterglow can be described as F_nu ~ nu**(-0.74 +/- 0.05) or flatter between optical and X-ray, which, together with the slow initial decay, is characteristic of standard adiabatic evolution in a uniformly dense medium. Assuming that a reported absorption-line redshift of 1.02 is correct, the apparent isotropic energy of 6.7 x 10**53 erg is reduced by a factor of ~ 200 in the jet model, and the initial half-opening angle is ~ 6 deg. GRB 99...

  9. Teach First Norway - who joins and what are their initial motivations for teaching?

    Directory of Open Access Journals (Sweden)

    Katrine Nesje

    2016-04-01

    Full Text Available Motivasjon for å undervise er et tema som er mye diskutert i offentlige debatter og i forskningslitteraturen. Grunnen til dette er at læreres profesjonelle motivasjon har vist seg å påvirke elevenes motivasjon, læreres tilfredshet i jobben, fravær og turnover i læreryrket, samt rekruttering av nye lærere. Alternative lærerutdanninger som tilbyr en raskere vei inn i læreryrket har i de senere årene blitt etablert, både i Norge og internasjonalt. Denne studien undersøker om den profesjonelle motivasjonen til kandidater som rekrutteres til disse programmene har spesielle kjennetegn. Artikkelen undersøker både motivasjon for undervisning og motivasjon for å delta i det alternative lederopplærings- og lærerutdanningsprogrammet Teach First Norway. Datamaterialet består av spørreskjemadata og intervjudata fra ett kull (N=13 Teach First Norway-kandidater. Basert på spørreskjemadata ble det utført en klyngeanalyse som fant tre motivasjonsprofiler: “Lav altruistisk motivasjon”, “Interesse for undervisning” og “Høy altruistisk motivasjon”. Ved hjelp av kvalitative intervjuer ble motivasjonsprofilene utdypet. Resultatene viser at samspillet mellom deltakernes ulike motivasjonsfaktorer er kompleks og unik. Det stereotype bildet av en Teach First Norway-kandidat som bruker programmet som et springbrett inn i lederstillinger i næringslivet nyanseres som følge av funnene.Nøkkelord: alternativ lærerutdanning, motivasjon for å undervise, karriere, Teach First NorwayAbstractTeacher motivation is a widely discussed topic in public debates and educational research literature. Prior research has found that teachers’ professional motivation impacts students’ motivation, teachers’ professional satisfaction, teacher absenteeism and turnover, as well as the recruitment of new teachers. Recently, the introduction of alternative teacher education programmes has provided a faster way into the teaching profession. This study

  10. On the strong metric dimension of corona product graphs and join graphs

    CERN Document Server

    Kuziak, Dorota; Rodriguez-Velazquez, Juan A

    2012-01-01

    Let $G$ be a connected graph. A vertex $w$ strongly resolves a pair $u$, $v$ of vertices of $G$ if there exists some shortest $u-w$ path containing $v$ or some shortest $v-w$ path containing $u$. A set $W$ of vertices is a strong resolving set for $G$ if every pair of vertices of $G$ is strongly resolved by some vertex of $W$. The smallest cardinality of a strong resolving set for $G$ is called the strong metric dimension of $G$. It is known that the problem of computing this invariant is NP-hard. It is therefore desirable to reduce the problem of computing the strong metric dimension of product graphs, to the problem of computing some parameter of the factor graphs. We show that the problem of finding the strong metric dimension of the corona product $G\\odot H$, of two graphs $G$ and $H$, can be transformed to the problem of finding certain clique number of $H$. As a consequence of the study we show that if $H$ has diameter two, then the strong metric dimension of $G\\odot H$ is obtained from the strong metri...

  11. Activation of C-H and B-H bonds through agostic bonding: an ELF/QTAIM insight.

    Science.gov (United States)

    Zins, Emilie-Laure; Silvi, Bernard; Alikhani, M Esmaïl

    2015-04-14

    Agostic bonding is of paramount importance in C-H bond activation processes. The reactivity of the σ C-H bond thus activated will depend on the nature of the metallic center, the nature of the ligand involved in the interaction and co-ligands, as well as on geometric parameters. Because of their importance in organometallic chemistry, a qualitative classification of agostic bonding could be very much helpful. Herein we propose descriptors of the agostic character of bonding based on the electron localization function (ELF) and Quantum Theory of Atoms in Molecules (QTAIM) topological analysis. A set of 31 metallic complexes taken, or derived, from the literature was chosen to illustrate our methodology. First, some criteria should prove that an interaction between a metallic center and a σ X-H bond can indeed be described as "agostic" bonding. Then, the contribution of the metallic center in the protonated agostic basin, in the ELF topological description, may be used to evaluate the agostic character of bonding. A σ X-H bond is in agostic interaction with a metal center when the protonated X-H basin is a trisynaptic basin with a metal contribution strictly larger than the numerical uncertainty, i.e. 0.01 e. In addition, it was shown that the weakening of the electron density at the X-Hagostic bond critical point with respect to that of X-Hfree well correlates with the lengthening of the agostic X-H bond distance as well as with the shift of the vibrational frequency associated with the νX-H stretching mode. Furthermore, the use of a normalized parameter that takes into account the total population of the protonated basin, allows the comparison of the agostic character of bonding involved in different complexes. PMID:25760795

  12. Ni/Al Multilayers Produced by Accumulative Roll Bonding and Sputtering

    Science.gov (United States)

    Simões, S.; Ramos, A. S.; Viana, F.; Emadinia, O.; Vieira, M. T.; Vieira, M. F.

    2016-10-01

    Ni/Al multilayers are known to transform into NiAl in a highly exothermic and self-sustaining reaction. The fact that this reaction has a high heat release rate and can be triggered by an external impulse, are reasons why it has already attracted much research attention. There is a huge potential in the use of Ni/Al multilayers as a controllable and localized heat source for joining temperature-sensitive materials such as microelectronic components. The heat released and the phases resulting from the reaction of Ni and Al multilayers depend on the production methods, their composition, as well as the bilayer thickness and annealing conditions. The present research aims to explore the influence of these variables on the reaction of different multilayers, namely those produced by accumulative roll bonding (ARB) and sputtering. Structural evolution of Ni/Al multilayers with temperature was studied by differential scanning calorimetry, x-ray diffraction and scanning electron microscopy. Phase evolution, heat release rate and NiAl final grain size are controlled by the ignition method used to trigger the reaction of Ni and Al. The potential use of these multilayers in the diffusion bonding of TiAl was analyzed. The ARB multilayers allow the production of joints with higher strength than the joints produced with commercial multilayers (NanoFoil®) produced by sputtering. However, the formation of brittle intermetallic phases (Ni3Al, Ni2Al3 and NiAl3) compromises the mechanical properties of the joint.

  13. Numerical Simulation on Joining of Ceramics with Metal by Friction Welding Technique

    Science.gov (United States)

    Jesudoss Hynes, N. Rajesh; Nagaraj, P.; Basil, S. Joshua

    The joining of ceramic and metals can be done by different techniques such as ultrasonic joining, brazing, transient liquid phase diffusion bonding, and friction welding. Friction Welding is a solid state joining process that generates heat through mechanical friction between a moving workpiece and a stationary component. In this article, numerical simulation on thermal analysis of friction welded ceramic/metal joint has been carried out by using Finite Element Analysis (FEA) software. The finite element analysis helps in better understanding of the friction welding process of joining ceramics with metals and it is important to calculate temperature and stress fields during the welding process. Based on the obtained temperature distribution the graphs were plotted between the lengths of the joint corresponding to the temperatures. To increase the wettability, aluminium sheet was used as an interlayer. Hence, numerical simulation of friction welding process is done by varying the interlayer sheet thickness. Transient thermal analysis had been carried out for each cases and temperature distribution was studied. From the simulation studies, it is found that the increase in interlayer thickness reduces the heat affected zone and eventually improves the joint efficiency of alumina/aluminum alloy joints.

  14. Seeking hydrogen bonds- with and without neutron diffraction

    International Nuclear Information System (INIS)

    The hydrogen-bond interaction can be studied using a variety of spectroscopic and crystallographic techniques, as well as theoretical studies based on quantum chemical principles, semi-empirical procedures, and statistical interpretations. A degree of specificity, along with flexibility, provides H-bonded systems with a variety of unusual and interesting physical, chemical and biological properties. Neutron diffraction is the method of choice for obtaining high-precision data on hydrogen-atom positions and hydrogen-bond stereo-chemistry in crystals. Neutron inelastic scattering can provide information on the dynamics of H-bonded systems. High-precision neutron diffraction studies on a variety of crystal hydrates, amino acids and small peptides, development of semi-empirical potential functions for bent-hydrogen bonds, and statistical analysis of H-bond populations associated with various donor and acceptor groups are some of the investigations on hydrogen bonding, carried out at Trombay during the past three decades. (author). 39 refs., 7 figs., 3 tabs

  15. Valence-Bond Concepts in Coordination Chemistry and the Nature of Metal-Metal Bonds.

    Science.gov (United States)

    Pauling, Linus; Herman, Zelek S.

    1984-01-01

    Discusses the valence-bond method, applying it to some coordination compounds of metals, especially those involving metal-metal bonds. Suggests that transition metals can form as many as nine covalent bonds, permitting valence-theory to be extended to transition metal compounds in a more effective way than has been possible before. (JN)

  16. Love and attachment: the psychobiology of social bonding.

    Science.gov (United States)

    Stein, Dan J; Vythilingum, Bavanisha

    2009-05-01

    Basic animal studies and human imaging studies have contributed to our understanding of the psychobiology of love and attachment. There are overlaps and distinctions in the neuronal circuitry of maternal love, romantic love, and long-term attachment. In these circuits, important molecules, which have been demonstrated to play a role in the psychobiology of social bonding include dopamine, serotonin, opioids, oxytocin, and vasopressin. Particular genetic and environmental variations contribute to social-bonding phenotypes, consistent with an evolutionary perspective on the value of these behaviors. Advances in the psychobiology of social bonds have led to hypotheses about the pharmacotherapy of disorders of attachment.

  17. Joining Technology of Dissimilar Materials for Automotive Components(Ⅱ)

    Institute of Scientific and Technical Information of China (English)

    Meung Ho Rhee; Jong Ho Song; Woo Young Chung; Young Myoung Kim

    2004-01-01

    Joining techniques of dissimilar materials for lightweight multi-material automotive body structure were discussed. The joining of 1 .4 mm thickness steel and 2 mm thickness of Al were performed by the new method that is hybrid laser welding system. After aluminum and steel were welded by laser hybrid welding process, the micro-structure investment and the micro-hardness test were carried out. Hybrid laser welding promises a bright future in joining technology of dissimilar materials for automotive components.

  18. New Joining Technology for Optimized Metal/Composite Assemblies

    OpenAIRE

    Holger Seidlitz; Lars Ulke-Winter; Lothar Kroll

    2014-01-01

    The development of a new joining technology, which is used to manufacture high strength hybrid constructions with thermoplastic composites (FRP) and metals, is introduced. Similar to natural regulation effects at trees, fibers around the FRP joint become aligned along the lines of force and will not be destroyed by the joining process. This is achieved by the local utilization of the specific plastic flow properties of the FRT and metal component. Compared with usual joining methods—such as f...

  19. Interface formation and strength of Be/DSCu diffusion bonding

    Energy Technology Data Exchange (ETDEWEB)

    Makino, T. [NGK Insulators Ltd., Nagoya (Japan). Mater. Res. Lab.; Iwadachi, T. [NGK Insulators Ltd., Handa-city (Japan). New Metals Div.

    1998-10-01

    Beryllium has been proposed to be used as a plasma facing material of the first wall for ITER, and will be bonded by HIP process to dispersion strengthened copper (DSCu). Be/DSCu diffusion bonding tests in the range of temperature from 600 C to 850 C by hot pressing techniques have been conducted to identify the effect of bonding temperature and time on interface formation and joint strength. The bonded Be/DSCu joints were evaluated by microstructural analysis of the interface and shear strength tests at room temperature. The diffusion layer of directly bonded Be/DSCu joints and the joints with Be-Cu interlayer consisted of Be{sub 2}Cu({delta}) phase on the Be side and Cu + BeCu({gamma}) phase on the DSCu side, Cu + BeCu({gamma}) phase generated remarkably fast at 800-850 C. The thickness of the diffusion layer was linear to a square root of bonding time. Shear strength of the joints bonded at 650-750 C are all around 200 MPa. Shear strength is dominated by the formation of the layer of Be{sub 2}Cu({delta}) phase on the Be side. (orig.) 2 refs.

  20. Interface formation and strength of Be/DSCu diffusion bonding

    Science.gov (United States)

    Makino, T.; Iwadachi, T.

    1998-10-01

    Beryllium has been proposed to be used as a plasma facing material of the first wall for ITER, and will be bonded by HIP process to Dispersion Strengthened Copper (DSCu). Be/DSCu diffusion bonding tests in the range of temperature from 600°C to 850°C by hot pressing techniques have been conducted to identify the effect of bonding temperature and time on interface formation and joint strength. The bonded Be/DSCu joints were evaluated by microstructural analysis of the interface and shear strength tests at room temperature. The diffusion layer of directly bonded Be/DSCu joints and the joints with Be-Cu interlayer consisted of Be 2Cu( δ) phase on the Be side and Cu + BeCu( γ) phase on the DSCu side. Cu + BeCu( γ) phase generated remarkably fast at 800-850°C. The thickness of the diffusion layer was linear to a square root of bonding time. Shear strength of the joints bonded at 650-750°C are all around 200 MPa. Shear strength is dominated by the formation of the layer of Be 2Cu( δ) phase on the Be side.