Torsional Shear Strength Tests for Glass-Ceramic Joined Silicon Carbide
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ferraris, Monica; Ventrella, Andrea; Salvo, Milena
2014-03-17
A torsion test on hour-glass-shaped samples with a full joined or a ring-shaped joined area was chosen in this study to measure shear strength of glass-ceramic joined silicon carbide. Shear strength of about 100 MPa was measured for full joined SiC with fracture completely inside their joined area. Attempts to obtain this shear strength with a ring-shaped joined area failed due to mixed mode fractures. However, full joined and ring-shaped steel hour-glasses joined by a glass-ceramic gave the same shear strength, thus suggesting that this test measures shear strength of joined components only when their fracture is completely inside theirmore » joined area.« less
In-network processing of joins in wireless sensor networks.
Kang, Hyunchul
2013-03-11
The join or correlated filtering of sensor readings is one of the fundamental query operations in wireless sensor networks (WSNs). Although the join in centralized or distributed databases is a well-researched problem, join processing in WSNs has quite different characteristics and is much more difficult to perform due to the lack of statistics on sensor readings and the resource constraints of sensor nodes. Since data transmission is orders of magnitude more costly than processing at a sensor node, in-network processing of joins is essential. In this paper, the state-of-the-art techniques for join implementation in WSNs are surveyed. The requirements and challenges, join types, and components of join implementation are described. The open issues for further research are identified.
In-Network Processing of Joins in Wireless Sensor Networks
Kang, Hyunchul
2013-01-01
The join or correlated filtering of sensor readings is one of the fundamental query operations in wireless sensor networks (WSNs). Although the join in centralized or distributed databases is a well-researched problem, join processing in WSNs has quite different characteristics and is much more difficult to perform due to the lack of statistics on sensor readings and the resource constraints of sensor nodes. Since data transmission is orders of magnitude more costly than processing at a sensor node, in-network processing of joins is essential. In this paper, the state-of-the-art techniques for join implementation in WSNs are surveyed. The requirements and challenges, join types, and components of join implementation are described. The open issues for further research are identified. PMID:23478603
McVey, Mitch
2010-01-01
DNA double-strand breaks are repaired by multiple mechanisms that are roughly grouped into the categories of homology-directed repair and non-homologous end joining. End-joining repair can be further classified as either classical non-homologous end joining, which requires DNA ligase 4, or “alternative” end joining, which does not. Alternative end joining has been associated with genomic deletions and translocations, but its molecular mechanism(s) are largely uncharacterized. Here, we report that Drosophila melanogaster DNA polymerase theta (pol theta), encoded by the mus308 gene and previously implicated in DNA interstrand crosslink repair, plays a crucial role in DNA ligase 4-independent alternative end joining. In the absence of pol theta, end joining is impaired and residual repair often creates large deletions flanking the break site. Analysis of break repair junctions from flies with mus308 separation-of-function alleles suggests that pol theta promotes the use of long microhomologies during alternative end joining and increases the likelihood of complex insertion events. Our results establish pol theta as a key protein in alternative end joining in Drosophila and suggest a potential mechanistic link between alternative end joining and interstrand crosslink repair. PMID:20617203
Kang, Hyunchul
2015-01-01
We investigate the in-network processing of an iceberg join query in wireless sensor networks (WSNs). An iceberg join is a special type of join where only those joined tuples whose cardinality exceeds a certain threshold (called iceberg threshold) are qualified for the result. Processing such a join involves the value matching for the join predicate as well as the checking of the cardinality constraint for the iceberg threshold. In the previous scheme, the value matching is carried out as the main task for filtering non-joinable tuples while the iceberg threshold is treated as an additional constraint. We take an alternative approach, meeting the cardinality constraint first and matching values next. In this approach, with a logical fragmentation of the join operand relations on the aggregate counts of the joining attribute values, the optimal sequence of 2-way fragment semijoins is generated, where each fragment semijoin employs a Bloom filter as a synopsis of the joining attribute values. This sequence filters non-joinable tuples in an energy-efficient way in WSNs. Through implementation and a set of detailed experiments, we show that our alternative approach considerably outperforms the previous one. PMID:25774710
A test of theory of planned behavior in Korea: participation in alcohol-related social gatherings.
Park, Hee Sun; Lee, Dong Wook
2009-12-01
Two studies are reported using the theory of planned behavior (TPB) to predict and explain joining and not joining alcohol-related social gatherings among Korean undergraduates in various engineering majors. Specifically, considering that the attitudinal component of TPB is behavioral-outcome-based, the current study investigated whether the outcomes of engaging in a behavior and of not engaging in a behavior would similarly predict intentions to engage in a behavior and intentions to not engage in a behavior. The current study also examined whether intentions to engage and intentions to not engage would be significantly related to self-reported behavior a week later. Participants in Study 1 reported TPB components (attitudes toward behavior, subjective norms, perceived behavioral control, and behavioral intentions) concerning joining alcohol-related social gatherings. Participants in Study 2 reported TPB components concerning not joining alcohol-related social gatherings. Additionally, a week later, the participants in both studies reported their participation in alcohol-related social gatherings from the past week. Generally, the results showed that the TPB components were significantly associated with undergraduates' intentions to join and intentions to not join. Specifically, conversation-related attitudes and senior-junior relationship-related attitudes were significantly related to intentions to join, and only group-related attitudes were significantly related to intentions to not join. Intentions to join and intentions to not join were not significantly related to self-reported behavior of joining alcohol-related social gatherings a week later. The findings from the current research provide some evidence that joining or not joining alcohol-related social gatherings may not be mere behavioral opposites, predictable by the presence or absence of the same behavioral outcomes. These two aspects of the behavior may require assessment of different behavioral outcomes or different assessments of the same behavioral outcomes.
NASA Technical Reports Server (NTRS)
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.
Joining of graphene flakes by low energy N ion beam irradiation
NASA Astrophysics Data System (ADS)
Wu, Xin; Zhao, Haiyan; Pei, Jiayun; Yan, Dong
2017-03-01
An approach utilizing low energy N ion beam irradiation is applied in joining two monolayer graphene flakes. Raman spectrometry and atomic force microscopy show the joining signal under 40 eV and 1 × 1014 cm-2 N ion irradiation. Molecular dynamics simulations demonstrate that the joining phenomenon is attributed to the punch-down effect and the subsequent chemical bond generation between the two sheets. The generated chemical bonds are made up of inserted ions (embedded joining) and knocked-out carbon atoms (saturation joining). The electronic transport properties of the joint are also calculated for its applications.
NASA Astrophysics Data System (ADS)
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 U.S. 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.
Conjoint Forming - Technologies for Simultaneous Forming and Joining
NASA Astrophysics Data System (ADS)
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.
Affordable, Robust Ceramic Joining Technology (ARCJoint) Developed
NASA Technical Reports Server (NTRS)
Steele, Gynelle C.
2001-01-01
Affordable, Robust Ceramic Joining Technology (ARCJoint) is a method for joining high temperature- resistant ceramic pieces together, establishing joints that are strong, and allowing joining to be done in the field. This new way of joining allows complex shapes to be formed by joining together geometrically simple shapes. The joining technology at NASA is one of the enabling technologies for the application of silicon-carbide-based ceramic and composite components in demanding and high-temperature applications. The technology is being developed and tested for high-temperature propulsion parts for aerospace use. Commercially, it can be used for joining ceramic pieces used for high temperature applications in the power-generating and chemical industries, as well as in the microelectronics industry. This innovation could yield big payoffs for not only the power-generating industry but also the Silicon Valley chipmakers. This technology, which was developed at the NASA Glenn Research Center by Dr. Mrityunjay Singh, is a two-step process involving first using a paste to join together ceramic pieces and bonding them by heating the joint to 110 to 120 C for between 10 and 20 min. This makes the joint strong enough to be handled for the final joining. Then, a silicon-based substance is applied to the joint and heated to 1400 C for 10 to 15 min. The resulting joint is as strong as the original ceramic material and can withstand the same high temperatures.
The joined wing - An overview. [aircraft tandem wings in diamond configurations
NASA Technical Reports Server (NTRS)
Wolkovitch, J.
1985-01-01
The joined wing is a new type of aircraft configuration which employs tandem wings arranged to form diamond shapes in plan view and front view. Wind-tunnel tests and finite-element structural analyses have shown that the joined wing provides the following advantages over a comparable wing-plus-tail system; lighter weight and higher stiffness, higher span-efficiency factor, higher trimmed maximum lift coefficient, lower wave drag, plus built-in direct lift and direct sideforce control capability. A summary is given of research performed on the joined wing. Calculated joined wing weights are correlated with geometric parameters to provide simple weight estimation methods. The results of low-speed and transonic wind-tunnel tests are summarized, and guidelines for design of joined-wing aircraft are given. Some example joined-wing designs are presented and related configurations having connected wings are reviewed.
Finite element thermal analysis for PMMA/st.st.304 laser direct joining
NASA Astrophysics Data System (ADS)
Hussein, Furat I.; Salloomi, Kareem N.; Akman, E.; Hajim, K. I.; Demir, A.
2017-01-01
This work is concerned with building a three-dimensional (3D) ab-initio models that is capable of predicting the thermal distribution of laser direct joining processes between Polymethylmethacrylate (PMMA) and stainless steel 304(st.st.304). ANSYS® simulation based on finite element analysis (FEA) was implemented for materials joining in two modes; laser transmission joining (LTJ) and conduction joining (CJ). ANSYS® simulator was used to explore the thermal environment of the joints during joining (heating time) and after joining (cooling time). For both modes, the investigation is carried out when the laser spot is at the middle of the joint width, at 15 mm from the commencement point (joint edge) at traveling time of 3.75 s. Process parameters involving peak power (Pp=3 kW), pulse duration (τ=5 ms), pulse repetition rate (PRR=20 Hz) and scanning speed (v=4 mm/s) are applied for both modes.
Akopiants, Konstantin; Zhou, Rui-Zhe; Mohapatra, Susovan; Valerie, Kristoffer; Lees-Miller, Susan P; Lee, Kyung-Jong; Chen, David J; Revy, Patrick; de Villartay, Jean-Pierre; Povirk, Lawrence F
2009-07-01
XLF/Cernunnos is a core protein of the nonhomologous end-joining pathway of DNA double-strand break repair. To better define the role of Cernunnos in end joining, whole-cell extracts were prepared from Cernunnos-deficient human cells. These extracts effected little joining of DNA ends with cohesive 5' or 3' overhangs, and no joining at all of partially complementary 3' overhangs that required gap filling prior to ligation. Assays in which gap-filled but unligated intermediates were trapped using dideoxynucleotides revealed that there was no gap filling on aligned DSB ends in the Cernunnos-deficient extracts. Recombinant Cernunnos protein restored gap filling and end joining of partially complementary overhangs, and stimulated joining of cohesive ends more than twentyfold. XLF-dependent gap filling was nearly eliminated by immunodepletion of DNA polymerase lambda, but was restored by addition of either polymerase lambda or polymerase mu. Thus, Cernunnos is essential for gap filling by either polymerase during nonhomologous end joining, suggesting that it plays a major role in aligning the two DNA ends in the repair complex.
A Modeling Approach for Plastic-Metal Laser Direct Joining
NASA Astrophysics Data System (ADS)
Lutey, Adrian H. A.; Fortunato, Alessandro; Ascari, Alessandro; Romoli, Luca
2017-09-01
Laser processing has been identified as a feasible approach to direct joining of metal and plastic components without the need for adhesives or mechanical fasteners. The present work sees development of a modeling approach for conduction and transmission laser direct joining of these materials based on multi-layer optical propagation theory and numerical heat flow simulation. The scope of this methodology is to predict process outcomes based on the calculated joint interface and upper surface temperatures. Three representative cases are considered for model verification, including conduction joining of PBT and aluminum alloy, transmission joining of optically transparent PET and stainless steel, and transmission joining of semi-transparent PA 66 and stainless steel. Conduction direct laser joining experiments are performed on black PBT and 6082 anticorodal aluminum alloy, achieving shear loads of over 2000 N with specimens of 2 mm thickness and 25 mm width. Comparison with simulation results shows that consistently high strength is achieved where the peak interface temperature is above the plastic degradation temperature. Comparison of transmission joining simulations and published experimental results confirms these findings and highlights the influence of plastic layer optical absorption on process feasibility.
Infrared transient-liquid-phase joining of SCS-6/ β21S titanium matrix composite
NASA Astrophysics Data System (ADS)
Blue, Craig A.; Sikka, Vinod K.; Blue, Randall A.; Lin, Ray Y.
1996-12-01
Fiber-reinforced titanium matrix composites (TMCs) are among the advanced materials being considered for use in the aerospace industry due to their light weight, high strength, and high modulus. A rapid infrared joining process has been developed for the joining of composites and advanced materials. Rapid infrared joining has been shown not to have many of the problems associated with conventional joining methods. Two models were utilized to predict the joint evolution and fiber reaction zone growth. Titanium matrix composite, 16-ply SCS-6/ β21S, has been successfully joined with total processing times of approximately 2 minutes, utilizing the rapid infrared joining technique. The process utilizes a 50 °C/s ramping rate, 17- µm Ti-15Cu-15Ni wt pct filler material between the faying surfaces; a joining temperature of 1100 °C; and 120 seconds of time to join the composite material. Joint shear-strength testing of the rapid infrared joints at temperatures as high as 800 °C has revealed no joint failures. Also, due to the rapid cooling of the process, no poststabilization of the matrix material is necessary to prevent the formation of a brittle omega phase during subsequent use of the TMC at intermediate temperatures, 270 °C to 430 °C, for up to 20 hours.
Reproductive performance of ewes grazing lucerne during different periods around mating.
Robertson, S M; Clayton, E H; Friend, M A
2015-11-01
High intake of lucerne pastures or feeding of other high quality diets during early pregnancy may increase embryo mortality, negating any benefit of improved nutrition on ovulation rate in ewes. This study was conducted to determine whether grazing ewes on lucerne (Medicago sativa) pastures for 7 days prior to and throughout joining would result in greater foetal numbers than if ewes were removed 7 days after the commencement of joining, or if ewes grazed senescent pasture throughout the joining period. Merino ewes (300) were allocated to two replicates of three treatments, grazing pastures between Days -7 and 36 of an unsynchronised, natural autumn joining. Grazing lucerne to Day 7 of joining resulted in 30% more (P<0.05) foetuses per ewe than grazing senescent pasture (1.60±0.07 and 1.31±0.07, respectively), and 19% more lambs marked per ewe joined. Extending grazing of lucerne past Day 7 of joining did not result in additional foetuses per ewe (1.61±0.06) in comparison with only grazing lucerne to Day 7 of joining. Greater than 80% of ewes mated during the first 14 days of joining, and the proportions of ewes returning to oestrus and re-mating (0.18±0.022) and of non-pregnant (0.09±0.017) ewes were similar (P>0.05) among all treatment groups, suggesting no differences between treatments in embryo mortality. Grazing naturally cycling ewes on lucerne prior to and during joinings in autumn is recommended as a means to increase the number of lambs born, although additional gains may not be obtained by grazing past day seven of joining. Copyright © 2015 Elsevier B.V. All rights reserved.
Thermoplastic Joining and Assembly of Bulk Metallic Glass Composites Through Capacitive Discharge
NASA Technical Reports Server (NTRS)
Roberts, Scott N. (Inventor); Schramm, Joseph P. (Inventor); Hofmann, Douglas C. (Inventor); Johnson, William L. (Inventor); Kozachkov, Henry (Inventor); Demetriou, Marios D. (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.
Toroid Joining Gun. [thermoplastic welding system using induction heating
NASA Technical Reports Server (NTRS)
Buckley, J. D.; Fox, R. L.; Swaim, R J.
1985-01-01
The Toroid Joining Gun is a low cost, self-contained, portable low powered (100-400 watts) thermoplastic welding system developed at Langley Research Center for joining plastic and composite parts using an induction heating technique. The device developed for use in the fabrication of large space sructures (LSST Program) can be used in any atmosphere or in a vacuum. Components can be joined in situ, whether on earth or on a space platform. The expanded application of this welding gun is in the joining of thermoplastic composites, thermosetting composites, metals, and combinations of these materials. Its low-power requirements, light weight, rapid response, low cost, portability, and effective joining make it a candidate for solving many varied and unique bonding tasks.
Welding and joining: A compilation
NASA Technical Reports Server (NTRS)
1975-01-01
A compilation is presented of NASA-developed technology in welding and joining. Topics discussed include welding equipment, techniques in welding, general bonding, joining techniques, and clamps and holding fixtures.
Laser microjoining of dissimilar and biocompatible materials
NASA Astrophysics Data System (ADS)
Bauer, Ingo; Russek, Ulrich A.; Herfurth, Hans J.; Witte, Reiner; Heinemann, Stefan; Newaz, Golam; Mian, A.; Georgiev, D.; Auner, Gregory W.
2004-07-01
Micro-joining and hermetic sealing of dissimilar and biocompatible materials is a critical issue for a broad spectrum of products such as micro-electronics, micro-optical and biomedical products and devices. Today, biocompatible titanium is widely applied as a material for orthopedic implants as well as for the encapsulation of implantable devices such as pacemakers, defibrillators, and neural stimulator devices. Laser joining is the process of choice to hermetically seal such devices. Laser joining is a contact-free process, therefore minimizing mechanical load on the parts to be joined and the controlled heat input decreases the potential for thermal damage to the highly sensitive components. Laser joining also offers flexibility, shorter processing time and higher quality. However, novel biomedical products, in particular implantable microsystems currently under development, pose new challenges to the assembly and packaging process based on the higher level of integration, the small size of the device's features, and the type of materials and material combinations. In addition to metals, devices will also include glass, ceramic and polymers as biocompatible building materials that must be reliably joined in similar and dissimilar combinations. Since adhesives often lack long-term stability or do not meet biocompatibility requirements, new joining techniques are needed to address these joining challenges. Localized laser joining provides promising developments in this area. This paper describes the latest achievements in micro-joining of metallic and non-metallic materials with laser radiation. The focus is on material combinations of metal-polymer, polymer-glass, metal-glass and metal-ceramic using CO2, Nd:YAG and diode laser radiation. The potential for applications in the biomedical sector will be demonstrated.
26 CFR 1.168(d)-1 - Applicable conventions-half-year and mid-quarter conventions.
Code of Federal Regulations, 2010 CFR
2010-04-01
... return year (i.e., July 1). (iv) In the case of a corporation that joins or leaves a consolidated group... placed in service by the joining or leaving member in the taxable year before it joins or after it leaves... test for the consolidated return year. If a corporation leaves a consolidated group and joins another...
Ceramic-to-Metal Joining for High Temperature, High Pressure Heat Exchangers
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mako, Frederick; Mako III, Frederick
2016-12-05
Designed and tested silicon carbide to metal joining and silicon carbide joining technology under high temperature and high pressure conditions. Determined that the joints maintained integrity and remained helium gas tight. These joined parts have been tested for mechanical strength, fracture toughness and hermeticity. A component testing chamber was designed and built and used for testing the joint integrity.
New local joining technique for metal materials using exothermic heat of Al/Ni multilayer powder
NASA Astrophysics Data System (ADS)
Izumi, Taisei; Kametani, Nagamasa; Miyake, Shugo; Kanetsuki, Shunsuke; Namazu, Takahiro
2018-06-01
The use of Al/Ni multilayer powders as a new heat source has been expected for metal joining technique owing to their instantaneous reaction and enormous amount of exothermic heat. In this study, the effects of the amount of Al/Ni multilayer powders on the electrical and mechanical properties of the joining part of Al strip specimens were examined. These electrical and mechanical properties were estimated by electric resistivity measurement using the four-terminal method and shear test, respectively. Experimental results show that Al specimens are successful joined under a limited condition and exhibit low electrical resistance and sufficiently high strength to maintain the joined state. However, overheating increases the amount of Al/Ni multilayer powder in the joined part, which causes considerable damage such as voids and dissolved loss. It is found that optimization of the amount of Al/Ni multilayer powder enables us to realize reliable joining of Al foils in electronics fields in the future.
NASA Astrophysics Data System (ADS)
Jiao, Junke; Xu, Zifa; Wang, Qiang; Sheng, Liyuan; Zhang, Wenwu
2018-07-01
Experiments with different joining parameters were carried out on fiber laser welding system to explore the mechanism of CFRTP/stainless steel joining and the influence of the parameters on the joining quality. The thermal defect and the microstructure of the joint was tested by SEM, EDS. The joint strength and the thermal defect zone width was measured by the tensile tester and the laser confocal microscope, respectively. The influence of parameters such as the laser power, the joining speed and the clamper pressure on the stainless steel surface thermal defect and the joint strength was analyzed. The result showed that the thermal defect on the stainless steel surface would change metal's mechanical properties and reduce its service life. A chemical bonding was found between the CFRTP and the stainless steel besides the physical bonding and the mechanical bonding. The highest shear stress was obtained as the laser power, the joining speed and the clamper pressure is 280 W, 4 mm/s and 0.15 MPa, respectively.
NASA Technical Reports Server (NTRS)
Mrityunjay, Singh; Gray, Hugh R. (Technical Monitor)
2002-01-01
Fiber reinforced ceramic matrix composites are under active consideration for use in a wide variety of high temperature applications within the aeronautics, energy, process, and nuclear industries. The engineering designs require fabrication and manufacturing of complex shaped parts. In many instances, it is more economical to build up complex shapes by Joining simple geometrical shapes. Thus, joining and attachment have been recognized as enabling technologies for successful utilization of ceramic components in various demanding applications. In this presentation, various challenges and opportunities in design, fabrication, and testing of high temperature joints in ceramic matrix composites will be presented. Various joint design philosophies and design issues in joining of composites will be discussed along with an affordable, robust ceramic joining technology (ARCJoinT). A wide variety of ceramic composites, in different shapes and sizes, have been joined using this technology. Microstructure and mechanical properties of joints will be reported. Current status of various ceramic joining technologies and future prospects for their applications will also be discussed.
Joining of aluminum sheet and glass fiber reinforced polymer using extruded pins
NASA Astrophysics Data System (ADS)
Conte, Romina; Buhl, Johannes; Ambrogio, Giuseppina; Bambach, Markus
2018-05-01
The present contribution proposes a new approach for joining sheet metal and fiber reinforced composites. The joining process draws upon a Friction Stir Forming (FSF) process, which is performed on the metal sheet to produce slender pins. These pins are used to pierce through the composite. Joining is complete by forming a locking head out of the part if the pin sticks out of the composite. Pins of different diameters and lengths were produced from EN AW-1050 material, which were joined to glass fiber reinforced polyamide-6. The strength of the joint has been experimentally tested in order to understand the effect of the process temperature on the pins strength and therefore on the joining. The results demonstrate the feasibility of this new technique, which uses no excess material.
Welding and Joining of Titanium Aluminides
Cao, Jian; Qi, Junlei; Song, Xiaoguo; Feng, Jicai
2014-01-01
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. PMID:28788113
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rabin, B.H.
A simple modified tape casting procedure has been developed for application to ceramic joining when the joining materials are in powder form. The method involves preparation of a slurry from the powder, solvent, and thermoplastic binder, and then casting directly onto the joining surface using a moving doctor blade. Handling of the tape prior to joining is not necessary: therefore, binder content is minimized, plasticizers are not required, and viscosity is controlled by solvent content. The utility of this technique for producing joints with thin, uniform interlayers is demonstrated for silicon carbide materials joined with TiC + Ni and SiCmore » + Si.« less
Joining of dissimilar materials
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.
NASA Astrophysics Data System (ADS)
Das, A.; Bang, H. S.; Bang, H. S.
2018-05-01
Multi-material combinations of aluminium alloy and carbon-fiber-reinforced-plastics (CFRP) have gained attention in automotive and aerospace industries to enhance fuel efficiency and strength-to-weight ratio of components. Various limitations of laser beam welding, adhesive bonding and mechanical fasteners make these processes inefficient to join metal and CFRP sheets. Friction lap joining is an alternative choice for the same. Comprehensive studies in friction lap joining of aluminium to CFRP sheets are essential and scare in the literature. The present work reports a combined theoretical and experimental study in joining of AA5052 and CFRP sheets using friction lap joining process. A three-dimensional finite element based heat transfer model is developed to compute the temperature fields and thermal cycles. The computed results are validated extensively with the corresponding experimentally measured results.
ERIC Educational Resources Information Center
Rankin, Susan R.; Hesp, Grahaeme A.; Weber, Genevieve N.
2013-01-01
The study included 337 self-identified gay and bisexual fraternity members, with 170 joining their chapters in the year 2000 or after, 99 joining their chapters between the years 1990 and 1999, and 68 joining in the year 1989 or before. Participants who self-identified as gay or bisexual men and who joined in the year 2000 or after reported a more…
Willmore energy for joining of carbon nanostructures
NASA Astrophysics Data System (ADS)
Sripaturad, P.; Alshammari, N. A.; Thamwattana, N.; McCoy, J. A.; Baowan, D.
2018-06-01
Numerous types of carbon nanostructure have been found experimentally, including nanotubes, fullerenes and nanocones. These structures have applications in various nanoscale devices and the joining of these structures may lead to further new configurations with more remarkable properties and applications. The join profile between different carbon nanostructures in a symmetric configuration may be modelled using the calculus of variations. In previous studies, carbon nanostructures were assumed to deform according to perfect elasticity, thus the elastic energy, depending only on the axial curvature, was used to determine the join profile consisting of a finite number of discrete bonds. However, one could argue that the relevant energy should also involve the rotational curvature, especially when its size is comparable to the axial curvature. In this paper, we use the Willmore energy, a natural generalisation of the elastic energy that depends on both the axial and rotational curvatures. Catenoids are absolute minimisers of this energy and pieces of these may be used to join various nanostructures. We focus on the cases of joining a fullerene to a nanotube and joining two fullerenes along a common axis. By comparing our results with the earlier work, we find that both energies give similar joining profiles. Further work on other configurations may reveal which energy provides a better model.
Aerodynamic and structural studies of joined-wing aircraft
NASA Technical Reports Server (NTRS)
Kroo, Ilan; Smith, Stephen; Gallman, John
1991-01-01
A method for rapidly evaluating the structural and aerodynamic characteristics of joined-wing aircraft was developed and used to study the fundamental advantages attributed to this concept. The technique involves a rapid turnaround aerodynamic analysis method for computing minimum trimmed drag combined with a simple structural optimization. A variety of joined-wing designs are compared on the basis of trimmed drag, structural weight, and, finally, trimmed drag with fixed structural weight. The range of joined-wing design parameters resulting in best cruise performance is identified. Structural weight savings and net drag reductions are predicted for certain joined-wing configurations compared with conventional cantilever-wing configurations.
Friction stir lap joining of automotive aluminium alloy and carbon-fiber-reinforced plastic
NASA Astrophysics Data System (ADS)
Bang, H. S.; Das, A.; Lee, S.; Bang, H. S.
2018-05-01
Multi-material combination such as aluminium alloys and carbon-fiber-reinforced plastics (CFRP) are increasingly used in the aircraft and automobile industries to enhance strength-to-weight ratio of the respective parts and components. Various processes such as adhesive bonding, mechanical fasteners and laser beam joining were employed to join metal alloy and CFRP sheets. However, long processing time of adhesive bonding, extra weight induced by mechanical fasteners and high operating cost of the laser is major limitations of these processes. Therefore, friction stir welding is an alternative choice to overcome those limitations in joining of CFRP and aluminium alloys. In the present work, an attempt is undertaken to join AA5052 alloy and polyamide 66 CFRP sheets by friction stir lap joining technique using pinned and pin-less tools. The joint qualities are investigated extensively at different joining conditions using two different types of tools and surface ground aluminium sheets. The results show that pin-less tool and surface ground aluminium alloy can provide the suitable joint with maximum joint strength around 8 MPa.
A Review of Similar and Dissimilar Micro-joining of Nitinol
NASA Astrophysics Data System (ADS)
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.
Enabling Dissimilar Material Joining Using Friction Stir Scribe Technology
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hovanski, Yuri; Upadyay, Piyush; Kleinbaum, Sarah
2017-04-05
One challenge in adapting welding processes to dissimilar material joining is the diversity of melting temperatures of the different materials. Although the use of mechanical fasteners and adhesives have mostly paved the way for near-term implementation of dissimilar material systems, these processes only accentuate the need for low-cost welding processes capable of joining dissimilar material components regardless of alloy, properties, or melting temperature. Friction stir scribe technology was developed to overcome the challenges of joining dissimilar material components where melting temperatures vary greatly, and properties and/or chemistry are not compatible with more traditional welding processes. Although the friction stir scribemore » process is capable of joining dissimilar metals and metal/polymer systems, a more detailed evaluation of several aluminum/steel joints is presented herein to demonstrate the ability to both chemically and mechanically join dissimilar materials.« less
Enabling Dissimilar Material Joining Using Friction Stir Scribe Technology
Hovanski, Yuri; Upadyay, Piyush; Kleinbaum, Sarah; ...
2017-04-05
One challenge in adapting welding processes to dissimilar material joining is the diversity of melting temperatures of the different materials. Although the use of mechanical fasteners and adhesives have mostly paved the way for near-term implementation of dissimilar material systems, these processes only accentuate the need for low-cost welding processes capable of impartially joining dissimilar material components regardless of alloy, properties, or melting temperature. Friction stir scribe technology was developed to overcome the challenges of joining dissimilar material components where melting temperatures vary greatly, and properties and/or chemistry are not compatible with more traditional welding processes. Finally, although the frictionmore » stir scribe process is capable of joining dissimilar metals and metal/polymer systems, a more detailed evaluation of several aluminum/steel joints is presented herein to demonstrate the ability to both chemically and mechanically join dissimilar materials.« less
Design synthesis and optimization of joined-wing transports
NASA Technical Reports Server (NTRS)
Gallman, John W.; Smith, Stephen C.; Kroo, Ilan M.
1990-01-01
A computer program for aircraft synthesis using a numerical optimizer was developed to study the application of the joined-wing configuration to transport aircraft. The structural design algorithm included the effects of secondary bending moments to investigate the possibility of tail buckling and to design joined wings resistant to buckling. The structural weight computed using this method was combined with a statistically-based method to obtain realistic estimates of total lifting surface weight and aircraft empty weight. A variety of 'optimum' joined-wing and conventional aircraft designs were compared on the basis of direct operating cost, gross weight, and cruise drag. The most promising joined-wing designs were found to have a joint location at about 70 percent of the wing semispan. The optimum joined-wing transport is shown to save 1.7 percent in direct operating cost and 11 percent in drag for a 2000 nautical mile transport mission.
Stears, Keenan; Kerley, Graham I H; Shrader, Adrian M
2014-01-01
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.
Aluminum and stainless steel tubes joined by simple ring and welding process
NASA Technical Reports Server (NTRS)
Townhill, A.
1967-01-01
Duranel ring is used to join aluminum and stainless steel tubing. Duranel is a bimetal made up of roll-bonded aluminum and stainless steel. This method of joining the tubing requires only two welding operations.
Holographic optical assembly and photopolymerized joining of planar microspheres
Shaw, L. A.; Chizari, S.; Panas, R. M.; ...
2016-07-27
The aim of this research is to demonstrate a holographically driven photopolymerization process for joining colloidal particles to create planar microstructures fixed to a substrate, which can be monitored with real-time measurement. Holographic optical tweezers (HOT) have been used to arrange arrays of microparticles prior to this work; here we introduce a new photopolymerization process for rapidly joining simultaneously handled microspheres in a plane. Additionally, we demonstrate a new process control technique for efficiently identifying when particles have been successfully joined by measuring a sufficient reduction in the particles’ Brownian motion. Furthermore, this technique and our demonstrated joining approach enablemore » HOT technology to take critical steps toward automated additive fabrication of microstructures.« less
Bentley, Johanne; Diggle, Christine P.; Harnden, Patricia; Knowles, Margaret A.; Kiltie, Anne E.
2004-01-01
In human cells DNA double strand breaks (DSBs) can be repaired by the non-homologous end-joining (NHEJ) pathway. In a background of NHEJ deficiency, DSBs with mismatched ends can be joined by an error-prone mechanism involving joining between regions of nucleotide microhomology. The majority of joins formed from a DSB with partially incompatible 3′ overhangs by cell-free extracts from human glioblastoma (MO59K) and urothelial (NHU) cell lines were accurate and produced by the overlap/fill-in of mismatched termini by NHEJ. However, repair of DSBs by extracts using tissue from four high-grade bladder carcinomas resulted in no accurate join formation. Junctions were formed by the non-random deletion of terminal nucleotides and showed a preference for annealing at a microhomology of 8 nt buried within the DNA substrate; this process was not dependent on functional Ku70, DNA-PK or XRCC4. Junctions were repaired in the same manner in MO59K extracts in which accurate NHEJ was inactivated by inhibition of Ku70 or DNA-PKcs. These data indicate that bladder tumour extracts are unable to perform accurate NHEJ such that error-prone joining predominates. Therefore, in high-grade tumours mismatched DSBs are repaired by a highly mutagenic, microhomology-mediated, alternative end-joining pathway, a process that may contribute to genomic instability observed in bladder cancer. PMID:15466592
Development of a procedure for forming assisted thermal joining of tubes
NASA Astrophysics Data System (ADS)
Chen, Hui; Löbbe, Christian; Staupendahl, Daniel; Tekkaya, A. Erman
2018-05-01
With the demand of lightweight design in the automotive industry, not only the wall-thicknesses of tubular components of the chassis or spaceframe are continuously decreased. Also the thicknesses of exhaust system parts are reduced to save material and mass. However, thinner tubular parts bring about additional challenges in joining. Welding or brazing methods, which are utilized in joining tubes with specific requirements concerning leak tightness, are sensitive to the gap between the joining partners. Furthermore, a large joining area is required to ensure the durability of the joint. The introduction of a forming step in the assembled state prior to thermal joining can define and control the gap for subsequent brazing or welding. The mechanical pre-joint resulting from the previously described calibration step also results in easier handling of the tubes prior to thermal joining. In the presented investigation, a spinning process is utilized to produce force-fit joints of varying lengths and diameter reduction and form-fit joints with varying geometrical attributes. The spinning process facilitates a high formability and geometrical flexibility, while at the achievable precision is high and the process forces are low. The strength of the joints is used to evaluate the joint quality. Finally, a comparison between joints produced by forming with subsequent brazing and original tube is conducted, which presents the high performance of the developed procedure for forming assisted thermal joining.
Hofler, Richard A; Ortiz, Judith
2016-07-28
Little is known about the impact of joining an Accountable Care Organization (ACO) on primary care provider organization's costs. The purpose of this study was to determine whether joining an ACO is associated with an increase in a Rural Health Clinic's (RHC's) cost per visit. The analyses focused on cost per visit in 2012 and 2013 for RHCs that joined an ACO in 2012 and cost per visit in 2013 for RHCs that joined an ACO in 2013. The RHCs were located in nine states. Data were obtained from Medicare Cost Reports. The analysis was conducted taking a treatment effects approach where the treatment is joining an ACO. Propensity-score matching was employed to provide multiple single and pooled estimates of the average treatment effect on the treated. Four-hundred thirty four to 544 RHCs (depending on the type of analysis and the variables used) were used in the several analyses. Seven of the RHCs joined an ACO in 2012 and 14 joined an ACO in 2013. The mean cost per visit for RHCs that did not join an ACO rose 4.40 % from 2011 to 2012 whereas the mean cost per visit for RHCs that joined an ACO rose by triple: 13.5 %. All of the pooled estimates of the average treatment effect on the treated from the propensity-score matching showed that joining an ACO was associated with higher mean cost per visit. The range of the estimated mean cost per visit differences was $17.19 (p value = 0.00) to $25.19 (p value = 0.00). This study is one of the first to describe the cost of ACO participation from the perspective of primary care provider organizations. It appears that for at least one type of primary care provider - the RHC - there are substantial costs associated with ACO participation during the first two years.
NASA Technical Reports Server (NTRS)
Singh, Mrityunjay
2006-01-01
Advanced ceramics and fiber reinforced composites are under active consideration for use in a wide variety of high temperature applications within the aeronautics, space transportation, energy, and nuclear industries. The engineering designs of ceramic and composite components require fabrication and manufacturing of large and complex shaped parts of various thicknesses. In many instances, it is more economical to build up complex shapes by joining simple geometrical shapes. In addition, these components have to be joined or assembled with metallic sub-components. Thus, joining and attachment have been recognized as enabling technologies for successful utilization of ceramic components in various demanding applications. In this presentation, various challenges and opportunities in design, fabrication, and testing of high temperature joints in advanced ceramics and ceramic matrix composites will be presented. Silicon carbide based advanced ceramics and fiber reinforced composites in different shapes and sizes, have been joined using an affordable, robust ceramic joining technology. In addition, some examples of metal-ceramic brazing will also be presented. Microstructure and high temperature mechanical properties of joints in silicon carbide ceramics and composites will be reported. Various joint design philosophies and design issues in joining of ceramics and composites will be discussed.
NASA Astrophysics Data System (ADS)
Adachi, Kazunari; Uchiyama, Kenta; Kuriyama, Takashi; Miyata, Ken; Hisamatsu, Tokuro
2009-11-01
The authors previously determined that thermal effects are not a dominant factor in the ultrasonic joining of very low density polyethylene (VLDPE) films using torsional vibration. Now, to confirm that the plastic materials are not “melted” by mechanically generated heat in the joining, they have conducted joining experiments for thin poly(ethylene terephthalate) (PET) films. The temperature at the interface of two PET films of 0.1 mm thickness only increased to approximately 100 °C, and no trace of liquidation of the material was observed at the interface under a polarizing microscope. Investigation using a differential scanning calorimeter (DSC) revealed that the “melting point” of PET is about 260 °C, and an ultrasonically joined specimen showed no significant difference in thermal characteristics compared with an intact PET film. It was also determined that the PET films cannot be joined even after being pressed together for a period of 30 min or longer at approximately 150 °C. From the results obtained using the microscope and the DSC, the authors conclude that melting of the materials plays essentially no role in ultrasonic plastic joining.
JOINING DISSIMILAR MATERIALS USING FRICTION STIR SCRIBE TECHNIQUE
DOE Office of Scientific and Technical Information (OSTI.GOV)
Upadhyay, Piyush; Hovanski, Yuri; Jana, Saumyadeep
2016-09-01
Development of robust and cost effective method of joining dissimilar materials can provide a critical pathway to enable widespread use of multi-material design and components in mainstream industrial applications. The use of multi-material components such as Steel-Aluminum, Aluminum-Polymer allows design engineers to optimize material utilization based on service requirements and often lead weight and cost reductions. However producing an effective joint between materials with vastly different thermal, microstructural and deformation response is highly problematic using conventional joining and /or fastening methods. This is especially challenging in cost sensitive high volume markets that largely rely on low–cost joining solutions. Friction Stirmore » Scribe technology was developed to meet the demands of joining materials with drastically different properties and melting regimes. The process enables joining of light metals like Magnesium and Aluminum to high temperature materials like Steels and Titanium. Additionally viable joints between polymer composites and metal can also be made using this method. This paper will present state of the art, progress made and challenges associated with this innovative derivative of Friction Stir welding in reference to joining dissimilar metals and polymer/metal combinations.« less
Chen, Chao; Zhao, Shengdun; Han, Xiaolan; Wang, Yongfei; Zhao, Xuzhe
2017-12-15
In recent years, the use of aluminum alloy has tended to increase for building lightweight automobiles to reduce their automotive weight, which is helpful to save energy and protect the environment. In order to join aluminum alloy, a flat-clinching process combined with material forming technology was investigated to join aluminum alloy sheets using an experimental and a numerical method. Al1060 was chosen as the material of the sheet, and DEFORM-2D software was used to build the numerical model. After the numerical model was validated by the experimental results, the influences of punch diameter and holder force on the materials deforming behavior of the clinched joint were analyzed using the numerical model. Then, the material flow, joining ability, and joining quality were investigated to assess the clinched joint. The results showed that an increase in punch diameter could give rise to an increase in neck thickness and interlocking length, while an increase in blank holder force induced a decrease in interlocking length and an increase in neck thickness. The joining quality could be increased by increasing the forming force. It can be concluded that a clinched joint has better joining quality for joining light-weight sheets onto automotive structures.
Joining Dissimilar Materials Using Friction Stir Scribe Technique
DOE Office of Scientific and Technical Information (OSTI.GOV)
Upadhyay, Piyush; Hovanski, Yuri; Jana, Saumyadeep
2016-10-03
Development of a robust and cost-effective method of joining dissimilar materials could provide a critical pathway to enable widespread use of multi-material designs and components in mainstream industrial applications. The use of multi-material components such as steel-aluminum and aluminum-polymer would allow design engineers to optimize material utilization based on service requirements and could often lead to weight and cost reductions. However, producing an effective joint between materials with vastly different thermal, microstructural, and deformation responses is highly problematic using conventional joining and/or fastening methods. This is especially challenging in cost sensitive, high volume markets that largely rely on low costmore » joining solutions. Friction stir scribe technology was developed to meet the demands of joining materials with drastically different properties and melting regimes. The process enables joining of light metals like magnesium and aluminum to high temperature materials like steel and titanium. Viable joints between polymer composites and metal can also be made using this method. This paper will present the state of the art, progress made, and challenges associated with this innovative derivative of friction stir welding in reference to joining dissimilar metals and polymer/metal combinations.« less
Laser hybrid joining of plastic and metal components for lightweight components
NASA Astrophysics Data System (ADS)
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.
NASA Technical Reports Server (NTRS)
Miller, F. R.
1972-01-01
Joining processes for aerospace systems combine fusion welding and solid state joining during production of metal structures. Detailed characteristics of electron beam welding, plasma arc welding, diffusion welding, inertia welding and weldbond processes are discussed.
Advanced concepts in joining by conventional processes
DOE Office of Scientific and Technical Information (OSTI.GOV)
Edwards, G.R.; Fasching-James, A.A.; Onsoien, M.I.
1994-12-31
Innovations which can be made to conventional arc welding processes so that advanced materials can be more efficiently joined are considered. Three examples are discussed: (1) GTA welding of iron aluminides, (2) GMA welding of advanced steels, and (3) SMA welding of structural steels. Advanced materials present new challenges for the materials joining specialist. The three examples discussed in this paper demonstrate, however, that modest but creative alterations of conventional GTAW, GMAW, or SMAW processes can provide new and better controls for solving advanced materials joining problems.
Simpson-Arbuckle contact revisited in Northwest Oklahoma County, Oklahoma
DOE Office of Scientific and Technical Information (OSTI.GOV)
Allison, M.D.; Allen, R.W.
The Joins Formation, the lowermost formation of the Simpson Group, is traditionally the least studied or understood of the Simpson formations. The Joins, not known to produce hydrocarbons in central Oklahoma, is frequently overlooked by those more interested in the productive Simpson formations above and the Arbuckle carbonates below. In a study of the lower Simpson to upper Arbuckle interval in northwestern Oklahoma County, Oklahoma, the Joins Formation was found to be present. The central Oklahoma section consists of interbedded gray, olive gray and green splintery moderately waxy shale, cream to light gray homogeneous microcrystallin dolomite, and microcrystalline to finemore » crystalline fossiliferous slightly glauconitic well cemented sandstones are also noted. The entire Joins Formation is moderately to very fossiliferous; primarily consisting of crinoids, ostracods, brachiopods, and trilobites. The ostracod fauna closely resembles and correlates with the Arbuckle Mountain section, which has been extensively studied over the years by such authors as Taff, Ulrich and Harris. Beneath the Joins in this area is a normal section of Arbuckle dolomites. Due to the absence of a basal sand in the Joins the separation of the Joins and Arbuckle, utilizing electric logs only, is frequently tenuous. In comparison with the Arbuckle, the Joins tends to have higher gamma ray and S.P. values. Other tools, such as resistivity, bulk density and photoelectric (PE), are frequently inconclusive. For geologists studying the Simpson-Arbuckle contact in central Oklahoma, the presence or absence of the Joins Formation is best determined through conventional lithologic and palenontologic sample identification techniques. Once this has been done, correlation of electric logs with this type log is possible for the local area.« less
Telles, Guilherme P; Araújo, Graziela S; Walter, Maria E M T; Brigido, Marcelo M; Almeida, Nalvo F
2018-05-16
In phylogenetic reconstruction the result is a tree where all taxa are leaves and internal nodes are hypothetical ancestors. In a live phylogeny, both ancestral and living taxa may coexist, leading to a tree where internal nodes may be living taxa. The well-known Neighbor-Joining heuristic is largely used for phylogenetic reconstruction. We present Live Neighbor-Joining, a heuristic for building a live phylogeny. We have investigated Live Neighbor-Joining on datasets of viral genomes, a plausible scenario for its application, which allowed the construction of alternative hypothesis for the relationships among virus that embrace both ancestral and descending taxa. We also applied Live Neighbor-Joining on a set of bacterial genomes and to sets of images and texts. Non-biological data may be better explored visually when their relationship in terms of content similarity is represented by means of a phylogeny. Our experiments have shown interesting alternative phylogenetic hypothesis for RNA virus genomes, bacterial genomes and alternative relationships among images and texts, illustrating a wide range of scenarios where Live Neighbor-Joining may be used.
Feasibility of community-based health insurance in rural tropical Ecuador.
Eckhardt, Martin; Forsberg, Birger Carl; Wolf, Dorothee; Crespo-Burgos, Antonio
2011-03-01
The main objective of this study was to assess people's willingness to join a community-based health insurance (CHI) model in El Páramo, a rural area in Ecuador, and to determine factors influencing this willingness. A second objective was to identify people's understanding and attitudes toward the presented CHI model. A cross-sectional survey was carried out using a structured questionnaire. Of an estimated 829 households, 210 were randomly selected by two-stage cluster sampling. Attitudes toward the scheme were assessed. Information on factors possibly influencing willingness to join was collected and related to the willingness to join. To gain an insight into a respondent's possible ability to pay, health care expenditure on the last illness episode was assessed. Feasibility was defined as at least 50% of household heads willing to join the scheme. Willingness to join the CHI model for US$30 per year was 69.3%. With affiliation, 92.2% of interviewees stated that they would visit the local health facility more often. Willingness to join was found to be negatively associated with education. Other variables showed no significant association with willingness to join. The study showed a positive attitude toward the CHI scheme. Substantial health care expenditures on the last illness episode were documented. The investigation concludes that CHI in the study region is feasible. However, enrollments are likely to be lower than the stated willingness to join. Still, a CHI scheme should present an interesting financing alternative in rural areas where services are scarce and difficult to sustain.
The Joining-Up Process: Issues in Effective Human Resource Development
ERIC Educational Resources Information Center
Frohman, Alan L.; Kotter, John P.
1975-01-01
Four specific problems associated with ineffective and expensive joining-up which are examined in the article are: (1) mismatched expectations; (2) stifling creativity and challenge; (3) lack of managerial awareness and sensitivity to joining-up issues; and (4) using inappropriate or incomplete screening criteria. Solutions are suggested; a table…
Fermilab Friends for Science Education | Join Us
Fermilab Friends for Science Education FFSE Home About Us Join Us Support Us Contact Us Join Us photo Fermilab Friends for Science Education (FFSE) needs you now! More than ever our society and improving science (science, technology, engineering and mathematics) education. Your donation allows us to
Joining Forces. A Team Approach to Secondary School Development.
ERIC Educational Resources Information Center
Miller, Rima; Corcoran, Thomas B.
This manual is designed to guide the implementation of the Joining Forces Program, a comprehensive improvement process for secondary schools. Implementation of the program requires the cooperative effort of the local school district, state and local education associations, and the administration and staff of participating schools. Joining Forces…
Newly Branded Energy Systems Integration Group Joins International
research fellow at NREL. Likewise, UVIG sees opportunity in partnering with iiESI. The international Group Joins International Institute for Energy Systems Integration Newly Branded Energy Systems Integration Group Joins International Institute for Energy Systems Integration March 22, 2018 The world of
Joining of advanced materials by superplastic deformation
Goretta, Kenneth C.; Routbort, Jules L.; Gutierrez-Mora, Felipe
2008-08-19
A method for utilizing superplastic deformation with or without a novel joint compound that leads to the joining of advanced ceramic materials, intermetallics, and cermets. A joint formed by this approach is as strong as or stronger than the materials joined. The method does not require elaborate surface preparation or application techniques.
Joining of advanced materials by superplastic deformation
Goretta, Kenneth C.; Routbort, Jules L.; Gutierrez-Mora, Felipe
2005-12-13
A method for utilizing superplastic deformation with or without a novel joint compound that leads to the joining of advanced ceramic materials, intermetallics, and cermets. A joint formed by this approach is as strong as or stronger than the materials joined. The method does not require elaborate surface preparation or application techniques.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Golovashchenko, Sergey Fedorovich; Bonnen, John Joseph Francis
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.
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.
NASA Astrophysics Data System (ADS)
Ferasat, Keyvan; Aashuri, Hossein; Kokabi, Amir Hossein; Shafizadeh, Mahdi; Nikzad, Siamak
2015-12-01
Semisolid stir joining has been under deliberation as a possible method for joining of copper alloys. In this study, the effect of temperature and rotational speed of stirrer on macrostructure evaluation and mechanical properties of samples were investigated. Optical microscopy and X-ray diffraction were performed for macro and microstructural analysis. A uniform micro-hardness profile was attained by semisolid stir joining method. The ultimate shear strength and bending strength of welded samples were improved in comparison with the cast sample. There is also lower area porosity in welded samples than the cast metal. The mechanical properties were improved by increasing temperature and rotational speed of the joining process.
Prospects of joining multi-material structures
NASA Astrophysics Data System (ADS)
Sankaranarayanan, R.; Hynes, N. Rajesh Jesudoss
2018-05-01
Spring up trends and necessities make the pipelines for the brand new Technologies. The same way, Multimaterial structures emerging as fruitful alternatives for the conventional structures in the manufacturing sector. Especially manufacturing of transport vehicles is placing a perfect platform for these new structures. Bonding or joining technology plays a crucial role in the field of manufacturing for sustainability. These latest structures are purely depending on such joining technologies so that multi-material structuring can be possible practically. The real challenge lies on joining dissimilar materials of different properties and nature. Escalation of thermoplastic usage in large structural components also faces similar ambiguity for joining multi-material structures. Adhesive bonding, mechanical fastening and are the answering technologies for multi-material structures. This current paper analysis the prospects of these bonding technologies to meet the challenges of tomorrow.
Nick McElhinny, Stephanie A; Ramsden, Dale A
2004-08-01
The nonhomologous end-joining pathway is a major means for repairing double-strand breaks (DSBs) in all mitotic cell types. This repair pathway is also the only efficient means for resolving DSB intermediates in V(D)J recombination, a lymphocyte-specific genome rearrangement required for assembly of antigen receptors. A role for polymerases in end-joining has been well established. They are a major factor in determining the character of repair junctions but, in contrast to 'core' end-joining factors, typically appear to have a subtle impact on the efficiency of end-joining. Recent work implicates several members of the Pol X family in end-joining and suggests surprising complexity in the control of how these different polymerases are employed in this pathway.
Self-Pierce Riveting of Three Aluminium Alloy and Mild Steel Sheets
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mori, K.; Abe, Y.; Sakai, S.
2010-06-15
Three aluminium alloy and steel sheets were joined with a self-piercing rivet. Self-pierce riveting has the function of joining steel and aluminium alloys having very different melting points due to plastic joining. The requisites for joining the three sheets are the driving of the rivet leg through the middle sheet, the flaring of the rivet leg in the lower sheet and the prevention of the fracture of the lower sheet. The joinability for various combinations of the three sheets was determined. When the rivet leg is small, no driving through the middle sheet occurs, the lower sheet ruptures for amore » large rivet leg. In addition, 980 MPa high strength steel, mild steel and aluminium alloy sheets were joined by the self-pierce riveting.« less
Evaluating the Upset Protrusion Joining (UPJ) Method to Join magnesium Castings to Dissimilar Metals
DOE Office of Scientific and Technical Information (OSTI.GOV)
Logan, Stephen D.
2015-08-19
This presentation discusses advantages and best practices for incorporating magnesium in automotive component applications to achieve substantial mass reduction, as well as some of the key challenges with respect to joining, coating, and galvanic corrosion, before providing an introduction and status update of the U.S. Department of Energy and Department of Defense jointly sponsored Upset Protrusion Joining (UPJ) process development and evaluation project. This update includes sharing performance results of a benchmark evaluation of the self-pierce riveting (SPR) process for joining dissimilar magnesium (Mg) to aluminum (Al) materials in four unique coating configurations before introducing the UPJ concept and comparingmore » performance results of the joints made with the UPJ process to those made with the SPR process.« less
NASA Technical Reports Server (NTRS)
Singh, M.
2004-01-01
Silicon carbide based advanced ceramics and fiber reinforced composites are under active consideration for use in wide variety of high temperature applications within the aeronautics, space transportation, energy, and nuclear industries. The engineering designs of ceramic and composite component require fabrication and manufacturing of large and complex shaped parts of various thicknesses. In many instances, it is more economical to build up complex shapes by joining simple geometrical shapes. In addition these components have to be joined or assembled with metallic sub-components. Thus, joining and attachment have been recognized as enabling technologies for successful utilization of ceramic components in various demanding applications. In this presentation, various challenges and opportunities in design, fabrication, and testing o high temperature joints in ceramic matrix composites will be presented. Silicon carbide based advanced ceramics (CVD and hot pressed), and C/SiC and SiC/SiC composites, in different shapes and sizes, have been joined using an affordable, robust ceramic joining technology (ARCJoinT). Microstructure and high temperature mechanical properties of joints in silicon carbide ceramics and CVI and melt infiltrated SiC matrix composites will,be reported. Various joint design philosophies and design issues in joining of ceramics and composites well be discussed.
Improving Self-Pierce Rivet Performance through Processing and Alloy Development
NASA Astrophysics Data System (ADS)
Van Hall, Stephen N.
Spot welding has been used to join steel sheet material in the past during automotive manufacturing. The increasing use of aluminum and mixed materials to achieve continually increasing fuel economy standards requires mechanical joining methods to provide adequate impact performance. One such mechanical joining process is self-pierce riveting (SPR). Self-pierce riveting has grown in popularity in recent years due to fast cycle times, high static strength and fatigue performance as well as the ability to join many different sheet material combinations. Self-pierce rivet utilization has become limited due to the material properties of the rivet in two main areas: the joining of high-strength sheet material and joining of multiple sheet material combinations using a single rivet geometry, referred to as commonization. Two specific case studies have been developed to assess the failures that occur and evaluate potential solutions: joining of press-hardened steel (PHS) to Al6111 and improved commonization ability using a two layer aluminum joint that is currently joined with a specialized rivet. Riveting trials have been performed on each of the two case studies using cold forged rivets produced from 10B37 steel that has been heat-treated through a quench and temper process to a range of hardness levels to evaluate the failures that occur within the rivet. The failures occur with two different modes: buckling of the rivet at hardness values below 550 HV when joining PHS and Al6111 and fractures that occur in the rivet tail at hardness values above 550 HV during joining in each of the case studies under evaluation. The fractures have been attributed to a high degree of hoop strain that forms when the rivets are flared beyond the design specifications. A method to replicate the rivet flaring procedure under laboratory conditions has been developed by flaring the rivets through various strain paths to induce a hoop strain and the resultant fractures. The flaring method shows the ability to replicate the types of fractures that were observed during joining attempts while monitoring applied force, crosshead displacement and strain at the point of fracture at the rivet tail using digital image correlation. Alternative alloys including 4130, 4340 and 5160 were evaluated alongside 10B37 for improved performance after quenching and tempering, austempering and after being intentionally decarburized to varying degrees. The heat-treatments were evaluated through microscopy, fractography, rivet flaring and joining attempts for each case study and alloy under investigation. All of the alternative alloys showed no significant performance gains after being quenched and tempered or austempered. However, hoop strain to failure during flaring was increased between 2-4x after the rivets had been intentionally decarburized. The intentionally decarburized rivets were evaluated through joining trials and provided successful joining for each of the case studies under investigation using 10B37 rivets. Rivets produced from 4340 and 5160 also showed instances of success during joining attempts. The Cockroft and Latham failure criterion was evaluated in regards to rivet flaring through the development of finite element simulations using Abaqus. The Cockroft and Latham failure criterion was able to successfully predict the location of riveting fractures through multiple strain paths, rivet geometries and microstructures. Cockroft and Latham values from tensile tests of 10B37 wire led to an underestimate of the strain to failure when compared to the rivet flaring process for quenched and tempered rivets but was very similar to the strain predicted for rivets that had been intentionally decarburized.
High-precision and high-speed laser microjoining for electronics and microsystems
NASA Astrophysics Data System (ADS)
Gillner, Arnold; Olowinsky, Alexander; Klages, Kilian; Gedicke, Jens; Sari, Fahri
2006-02-01
The joining processes in electronic device manufacturing are today still dominated by conventional joining techniques like press fitting, crimping and resistance welding. Laser beam joining techniques have been under intensive investigations and subsequently new processes for mass manufacturing and high accuracy assembling were established. With the newly developed SHADOW (R) welding technology technical aspects such as tensile strength, geometry and precision of the weld could be improved. This technology provides highest flexibility in weld geometry with a minimum welding time as well as new possibilities in using application adapted materials. Different parts and even different metals can be joined by a non-contact process. The application of a relative movement between the laser beam and the part to be joined at feed rates of up to 60 m/min produces weld seams with a length from 0.6 mm to 15.7 mm using a pulsed Nd:YAG laser with a pulse duration of up to 50 ms. Due to the low energy input, typically 1 J to 6 J, a weld width as small as 50 μm and a weld depth as small as 20 pm have been attained. This results in low distortion of the joined watch components. Within this paper this new welding process will be explained and several examples of joined components will be presented with respect to fundamentals and the sustainable implementation of the SHADOW (R) welding technique into watch manufacturing and electronic industry. For microsystem applications the laser joining technology is modified to join even silicon and glass parts without any melting based on the formation of a thermally induced oxygen bond. New fields of applications for joining different materials such as steel to brass or steel to copper for electrical interconnects will be discussed. Here the SHADOW (R) welding technique offers new possibilities for the combination of good electrical properties of copper with high mechanical stiffness of steel. The paper will give a closer look to microjoining applications especially using the SHADOW (R) welding technique. Basics of the process as well as its application on dedicated examples will be shown for small parts such as axis-wheel combinations and electrical connectors.
The Flying Diamond: A joined aircraft configuration design project, volume 1
NASA Technical Reports Server (NTRS)
Ball, Chris; Czech, Joe; Lentz, Bryan; Kobashigawa, Daryl; Oishi, Curtis; Poladian, David
1988-01-01
The results of the analysis conducted on the Joined Wing Configuration study are presented. The joined wing configuration employs a conventional fuselage and incorporates two wings joined together near their tips to form a diamond shape in both plan view and front view. The arrangement of the lifting surfaces uses the rear wing as a horizontal tail and as a forward wing strut. The rear wing has its root at the tip of the vertical stabilizer and is structurally attached to the trailing edge of the forward wing. This arrangement of the two wings forms a truss structure which is inherently resistant to the aerodynamic bending loads generated during flight. This allows for a considerable reduction in the weight of the lifting surfaces. With smaller internal wing structures needed, the Joined Wing may employ thinner wings which are more suitable for supersonic and hypersonic flight, having less induced drag than conventional cantilever winged aircraft. Inherent in the Joined Wing is the capability of the generation of direct lift and side force which enhance the performance parameters.
Amjad, Naumana; Wood, Alex M
2009-01-01
Two studies investigated the role of beliefs about the acceptability of aggression ("normative beliefs") against Jews in determining who would join an extremist group. In Study 1, students in a university in Pakistan (N=144) completed self-report attitude measures, and were subsequently approached by a confederate who asked whether they wanted to join an extremist anti-Semitic organization. Normative beliefs about aggression against Jews were very strong predictors of whether participants agreed to join. In Study 2, participants (N=92) were experimentally assigned to either a brief educational intervention, designed to improve inter-group relations, or to a control group. They also filled in self-report attitude measures pre and post intervention. Participants in the intervention group were much less likely to agree to join the extremist group, and this effect of the intervention on joining was mediated by changes in normative beliefs about aggression against Jews. The results have implications for theories of inter-group aggression and interventions to prevent people from being recruited into extremist groups.
Laser beam joining of material combinations for automotive applications
NASA Astrophysics Data System (ADS)
Schubert, Emil; Zerner, Ingo; Sepold, Gerd
1997-08-01
An ideal material for automotive applications would combine the following properties: high corrosion resistance, high strength, high stiffness and not at least a low material price. Today a single material is not able to meet all these requirements. Therefore, in the future different materials will be placed where they meet the requirements best. The result of this consideration is a car body with many different alloys and metals, which have to be joined to one another. BIAS is working on the development of laser based joining technologies for different material combinations, especially for thin sheets used in automotive applications. One result of the research is a joining technology for an aluminum-steel-joint. Using a Nd:YAG laser the problem of brittle intermetallic phases between these materials was overcome. Using suitable temperature-time cycles, elected by a FEM-simulation, the thickness of intermetallic phases was kept below 10 micrometers . This technology was also applied to coated steels, which were joined with different aluminum alloys. Further it is demonstrated that titanium alloys, e.g. used for racing cars, can also be joined with aluminum alloys.
NASA Astrophysics Data System (ADS)
Cavallaro, Rauno; Demasi, Luciano
2016-11-01
Diamond Wings, Strut- and Truss-Braced Wings, Box Wings, and PrandtlPlane, the so-called "JoinedWings", represent a dramatic departure from traditional configurations. Joined Wings are characterized by a structurally overconstrained layout which significantly increases the design space with multiple load paths and numerous solutions not available in classical wing systems. A tight link between the different disciplines (aerodynamics, flight mechanics, aeroelasticity, etc.) makes a Multidisciplinary Design and Optimization approach a necessity from the early design stages. Researchers showed potential in terms of aerodynamic efficiency, reduction of emissions and superior performances, strongly supporting the technical advantages of Joined Wings. This review will present these studies, with particular focus on the United States joined-wing SensorCraft, Strut- and Truss- Braced Wings, Box Wings and PrandtlPlane.
Morris, S T; Morel, P C H; Kenyon, P R
2006-04-01
To examine of the influence of liveweight (LW), condition (CS) and age of dam on inter-calving interval (ICI), date of calving, days from joining to calving, and birth and weaning weights of calves. LW and CS were measured in a herd of mixed-aged (3-8 years) Hereford x Friesian beef cows on four occasions, annually, over a 3-year period from joining (the date bulls were introduced into the herd at the start of a restricted breeding season) in November 2000 to weaning in March 2004. The four dates of weighing and condition-scoring were joining (November), weaning (March), winter (June), and pre-calving (August). Calves were tagged, identified to their dam, and weighed within 24 h of birth, and at weaning. Date of calving, ICI and days from joining to calving were determined. The CS and LW of cows varied between years. LW increased in cows up to 6 years of age. Three-year-old cows had a longer ICI than older cows. Change in CS and LW from winter to pre-calving and pre-calving to joining were negatively correlated with ICI for younger cows but not for cows > or = 5 years (CS) and 6-8 years (LW) old. No difference in CS or LW precalving was evident between cows that subsequently became pregnant compared with non-pregnant cows, although cows that became pregnant gained more condition from pre-calving to joining than non-pregnant cows. Pregnant cows were heavier and had higher CS at joining than non-pregnant cows. Young cows, up to second-mating as 3-year-olds, would benefit from separate nutritional management from older cows, to ensure ICI and days to conception are kept at targeted levels. In addition, increasing CS from pre-calving to joining and higher LW and CS at joining resulted in higher pregnancy rates.
Physician participation in alternative health plans
Rosenbach, Margo L.; Harrow, Brooke S.; Hurdle, Sylvia
1988-01-01
In this article, physician participation in alternative health plans is examined, using cross-sectional data from the Physicians' Practice Costs and Income Survey, 1983-85. Overall, about one-third of physicians participated in one or more plans, ranging from 18 percent of general practitioners to 46 percent of medical subspecialists. Only 19 percent, however, received income from prepaid sources, averaging $5,275 per physician. Reasons for joining or not joining are also examined. Participants joined most often to maintain or increase workload, while nonparticipants most often declined to join because they would be giving up independence. PMID:10312633
[Early prenatal diagnosis of diprosopic syncephalic joined twins].
Picaud, A; Nlome-Nze, A R; Engongha-Beka, T; Ogowet-Igumu, N
1990-06-01
The authors summarize the case of diprosopic syncephalic joined twins diagnosed at 22 weeks of pregnancy by ultrasonography performed because of hydramnios. The rate of separation anomalies of monozygotic twins is assessed by a review of the literature: from 1 to twenty to fifty thousands for joined twins to 1 per cent fifty thousand to fifteen millions for diprosopus. The etiology is the result of a late division of the egg between D12 and D16. Often an encephalic diprosopic joined twins cause elevated levels of maternal serum alpha protein. Early ultrasonography permits to consider a vaginal therapeutic abortion.
Performing a global barrier operation in a parallel computer
Archer, Charles J; Blocksome, Michael A; Ratterman, Joseph D; Smith, Brian E
2014-12-09
Executing computing tasks on a parallel computer that includes compute nodes coupled for data communications, where each compute node executes tasks, with one task on each compute node designated as a master task, including: for each task on each compute node until all master tasks have joined a global barrier: determining whether the task is a master task; if the task is not a master task, joining a single local barrier; if the task is a master task, joining the global barrier and the single local barrier only after all other tasks on the compute node have joined the single local barrier.
Laser beam joining of optical fibers in silicon V-grooves
NASA Astrophysics Data System (ADS)
Kaufmann, Stefan; Otto, Andreas; Luz, Gerhard
2000-06-01
The increasing use of optical data transmission systems and the development of new optical components require adjustment-insensitive and reliable joining and assembling techniques. The state of the art includes the utilization of silicon submounts with anisotropically etched V-grooves. Several glass fibers are fixed in these V-grooves with adhesive. Adhesive bonds tend towards degradation under the influence of temperature and moisture. For this reason, the alternative joining processes laser beam welding and laser beam soldering are relevant. The goal is a reliable joining of optical fibers in V-grooves without damage to the fibers or the silicon submount. Because of the anomaly of silicon during phase transformation, a positive joining can be realized by laser beam welding. A melt pool is created through the energy of a Nd:YAG-laser pulse. During solidification, the volume of silicon increases and a bump is formed in the center. Experiments have shown that this phenomenon can be used for joining optical fibers in silicon-V-grooves. With suitable parameters the silicon flows half around the fiber during solidification. For each fiber, several welding points are necessary. Another promising joining method is laser bema soldering. In this case, a second silicon sheet with a solder deposit is placed on the fibers which lie in the V-grooves of the metallized silicon submount. The laser heats the upper silicon until the solder metals by heat conduction.
The influence of performance-based payment on childhood immunisation coverage.
Merilind, Eero; Salupere, Rauno; Västra, Katrin; Kalda, Ruth
2015-06-01
Pay-for-performance, also called the quality system (QS) in Estonia, was implemented in 2006 and one indicator for achievement is the childhood immunisation coverage rate. The WHO vaccination coverage in Europe for diphtheria, tetanus and pertussis, and measles in children aged around one year old should meet or exceed 90 per cent. The study was conducted using a database from the Estonian Health Insurance Fund. The study compared childhood immunisation coverage rates of all Estonian family physicians in two groups, joined and not joined to the quality system during the observation period 2006-2012. Immunisation coverage was calculated as the percentage of persons in the target age group who received a vaccine dose by a given age. The target level of immunisations in Estonia is set at 90 per cent and higher. Immunisation coverage rates of family doctors (FD) in Estonia showed significant differences between two groups of doctors: joined to the quality system and not joined. Doctors joined to the quality system met the 90 per cent vaccination criterion more frequently compared to doctors not joined to the quality system. Doctors not joined to the quality system were below the 90 per cent vaccination criterion in all vaccinations listed in the Estonian State Immunisation Schedule. Pay-for-performance as a financial incentive encourages higher levels of childhood immunisations. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
News Release: USDA Joins Fair Food Network, State and Local Partners to
Promote Nutrition Resources for Lead-Affected Flint Residents - PHE You may be trying to access Joins Fair Food Network, State and Local Partners to Promote Nutrition Resources for Lead-Affected Flint Residents News Release: USDA Joins Fair Food Network, State and Local Partners to Promote Nutrition
Explosive Joining for the Mars Sample Return Mission
NASA Technical Reports Server (NTRS)
Bement, Laurence J.; Sanok, Joseph T.
2000-01-01
A unique, small-scale, ribbon explosive joining process is being developed as an option for closing and sealing a metal canister to allow the return of a pristine sample of the Martian surface and atmosphere to Earth. This joining process is accomplished by an explosively driven, high-velocity, angular collision of the metal, which melts and effaces the oxide films from the surfaces to allow valence electron sharing to bond the interface. Significant progress has been made through more than 100 experimental tests to meet the goals of this ongoing developmental effort. The metal of choice, aluminum alloy 6061, has been joined in multiple interface configurations and in complete cylinders. This process can accommodate dust and debris on the surfaces to be joined. It can both create and sever a joint at its midpoint with one explosive input. Finally, an approach has been demonstrated that can capture the back blast from the explosive.
Recommending teams promotes prosocial lending in online microfinance
Ai, Wei; Chen, Roy; Mei, Qiaozhu; Phillips, Webb
2016-01-01
This paper reports the results of a large-scale field experiment designed to test the hypothesis that group membership can increase participation and prosocial lending for an online crowdlending community, Kiva. The experiment uses variations on a simple email manipulation to encourage Kiva members to join a lending team, testing which types of team recommendation emails are most likely to get members to join teams as well as the subsequent impact on lending. We find that emails do increase the likelihood that a lender joins a team, and that joining a team increases lending in a short window (1 wk) following our intervention. The impact on lending is large relative to median lender lifetime loans. We also find that lenders are more likely to join teams recommended based on location similarity rather than team status. Our results suggest team recommendation can be an effective behavioral mechanism to increase prosocial lending. PMID:27974610
ERIC Educational Resources Information Center
Forbes, Joan, Ed.; Watson, Cate, Ed.
2011-01-01
Can we imagine different ways of working together to secure better outcomes for children and families? What are the complex issues that underlie the apparently simple call for "joined-up" services? Children's services in many countries around the world are being transformed as part of the call for "joined-up working for joined-up…
Joining of parts via magnetic heating of metal aluminum powders
Baker, Ian
2013-05-21
A method of joining at least two parts includes steps of dispersing a joining material comprising a multi-phase magnetic metal-aluminum powder at an interface between the at least two parts to be joined and applying an alternating magnetic field (AMF). The AMF has a magnetic field strength and frequency suitable for inducing magnetic hysteresis losses in the metal-aluminum powder and is applied for a period that raises temperature of the metal-aluminum powder to an exothermic transformation temperature. At the exothermic transformation temperature, the metal-aluminum powder melts and resolidifies as a metal aluminide solid having a non-magnetic configuration.
Method and apparatus for welding precipitation hardenable materials
Murray, Jr., Holt; Harris, Ian D.; Ratka, John O.; Spiegelberg, William D.
1994-01-01
A method for welding together members consisting of precipitation age hardened materials includes the steps of selecting a weld filler material that has substantially the same composition as the materials being joined, and an age hardening characteristic temperature age threshold below that of the aging kinetic temperature range of the materials being joined, whereby after welding the members together, the resulting weld and heat affected zone (HAZ) are heat treated at a temperature below that of the kinetic temperature range of the materials joined, for obtaining substantially the same mechanical characteristics for the weld and HAZ, as for the parent material of the members joined.
Method and apparatus for welding precipitation hardenable materials
Murray, H. Jr.; Harris, I.D.; Ratka, J.O.; Spiegelberg, W.D.
1994-06-28
A method for welding together members consisting of precipitation age hardened materials includes the steps of selecting a weld filler material that has substantially the same composition as the materials being joined, and an age hardening characteristic temperature age threshold below that of the aging kinetic temperature range of the materials being joined, whereby after welding the members together, the resulting weld and heat affected zone (HAZ) are heat treated at a temperature below that of the kinetic temperature range of the materials joined, for obtaining substantially the same mechanical characteristics for the weld and HAZ, as for the parent material of the members joined. 5 figures.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Shaw, L. A.; Chizari, S.; Panas, R. M.
The aim of this research is to demonstrate a holographically driven photopolymerization process for joining colloidal particles to create planar microstructures fixed to a substrate, which can be monitored with real-time measurement. Holographic optical tweezers (HOT) have been used to arrange arrays of microparticles prior to this work; here we introduce a new photopolymerization process for rapidly joining simultaneously handled microspheres in a plane. Additionally, we demonstrate a new process control technique for efficiently identifying when particles have been successfully joined by measuring a sufficient reduction in the particles’ Brownian motion. Furthermore, this technique and our demonstrated joining approach enablemore » HOT technology to take critical steps toward automated additive fabrication of microstructures.« less
Method of joining metallic and composite components
NASA Technical Reports Server (NTRS)
Semmes, Edmund B. (Inventor)
2010-01-01
A method is provided for joining a metallic member to a structure made of a composite matrix material. One or more surfaces of a portion of the metallic member that is to be joined to the composite matrix structure is provided with a plurality of outwardly projecting studs. The surface including the studs is brought into engagement with a portion of an uncured composite matrix material so that fibers of the composite matrix material intertwine with the studs, and the metallic member and composite structure form an assembly. The assembly is then companion cured so as to join the metallic member to the composite matrix material structure.
Laser beam soldering of micro-optical components
NASA Astrophysics Data System (ADS)
Eberhardt, R.
2003-05-01
MOTIVATION Ongoing miniaturisation and higher requirements within optical assemblies and the processing of temperature sensitive components demands for innovative selective joining techniques. So far adhesive bonding has primarily been used to assemble and adjust hybrid micro optical systems. However, the properties of the organic polymers used for the adhesives limit the application of these systems. In fields of telecommunication and lithography, an enhancement of existing joining techniques is necessary to improve properties like humidity resistance, laserstability, UV-stability, thermal cycle reliability and life time reliability. Against this background laser beam soldering of optical components is a reasonable joining technology alternative. Properties like: - time and area restricted energy input - energy input can be controlled by the process temperature - direct and indirect heating of the components is possible - no mechanical contact between joining tool and components give good conditions to meet the requirements on a joining technology for sensitive optical components. Additionally to the laser soldering head, for the assembly of optical components it is necessary to include positioning units to adjust the position of the components with high accuracy before joining. Furthermore, suitable measurement methods to characterize the soldered assemblies (for instance in terms of position tolerances) need to be developed.
Robust Joining and Integration Technologies for Advanced Metallic, Ceramic, and Composite Systems
NASA Technical Reports Server (NTRS)
Singh, M.; Shpargel, Tarah; Morscher, Gregory N.; Halbig, Michael H.; Asthana, Rajiv
2006-01-01
Robust integration and assembly technologies are critical for the successful implementation of advanced metallic, ceramic, carbon-carbon, and ceramic matrix composite components in a wide variety of aerospace, space exploration, and ground based systems. Typically, the operating temperature of these components varies from few hundred to few thousand Kelvin with different working times (few minutes to years). The wide ranging system performance requirements necessitate the use of different integration technologies which includes adhesive bonding, low temperature soldering, active metal brazing, diffusion bonding, ARCJoinT, and ultra high temperature joining technologies. In this presentation, a number of joining examples and test results will be provided related to the adhesive bonding and active metal brazing of titanium to C/C composites, diffusion bonding of silicon carbide to silicon carbide using titanium interlayer, titanium and hastelloy brazing to silicon carbide matrix composites, and ARCJoinT joining of SiC ceramics and SiC matrix composites. Various issues in the joining of metal-ceramic systems including thermal expansion mismatch and resulting residual stresses generated during joining will be discussed. In addition, joint design and testing issues for a wide variety of joints will be presented.
Affordable, Robust Ceramic Joining Technology (ARCJoinT) for High Temperature Applications
NASA Technical Reports Server (NTRS)
Singh, M.
1998-01-01
Ceramic joining is recognized as one of the enabling technologies for the successful utilization of silicon carbide-based monolithic ceramic and fiber reinforced composite components in a number of demanding and high temperature applications in aerospace and ground-based systems. An affordable, robust ceramic joining technology (ARCJoinT) for joining of silicon carbide-based ceramics and fiber reinforced composites has been developed. This technique is capable of producing joints with tailorable thickness and composition. A wide variety of silicon carbide-based ceramics and composites, in different shapes and sizes, have been joined using this technique. The room and high temperature mechanical properties and fractography of ceramic joints have been reported. In monolithic silicon carbide ceramics, these joints maintain their mechanical strength up to 1350 C in air. There is no change in the mechanical strength of joints in silicon carbide matrix composites up to 1200 C in air. In composites, simple butt joints yield only about 20% of the ultimate strength of the parent materials. This technology is suitable for the joining of large and complex shaped ceramic and composite components, and with certain modifications, can be applied to repair of ceramic components damaged in service.
Ad-Hoc Queries over Document Collections - A Case Study
NASA Astrophysics Data System (ADS)
Löser, Alexander; Lutter, Steffen; Düssel, Patrick; Markl, Volker
We discuss the novel problem of supporting analytical business intelligence queries over web-based textual content, e.g., BI-style reports based on 100.000's of documents from an ad-hoc web search result. Neither conventional search engines nor conventional Business Intelligence and ETL tools address this problem, which lies at the intersection of their capabilities. "Google Squared" or our system GOOLAP.info, are examples of these kinds of systems. They execute information extraction methods over one or several document collections at query time and integrate extracted records into a common view or tabular structure. Frequent extraction and object resolution failures cause incomplete records which could not be joined into a record answering the query. Our focus is the identification of join-reordering heuristics maximizing the size of complete records answering a structured query. With respect to given costs for document extraction we propose two novel join-operations: The multi-way CJ-operator joins records from multiple relationships extracted from a single document. The two-way join-operator DJ ensures data density by removing incomplete records from results. In a preliminary case study we observe that our join-reordering heuristics positively impact result size, record density and lower execution costs.
Aeroelastic tailoring and structural optimization of joined-wing configurations
NASA Astrophysics Data System (ADS)
Lee, Dong-Hwan
2002-08-01
Methodology for integrated aero-structural design was developed using formal optimization. ASTROS (Automated STRuctural Optimization System) was used as an analyzer and an optimizer for performing joined-wing weight optimization with stress, displacement, cantilever or body-freedom flutter constraints. As a pre/post processor, MATLAB was used for generating input file of ASTROS and for displaying the results of the ASTROS. The effects of the aeroelastic constraints on the isotropic and composite joined-wing weight were examined using this developed methodology. The aeroelastic features of a joined-wing aircraft were examined using both the Rayleigh-Ritz method and a finite element based aeroelastic stability and weight optimization procedure. Aircraft rigid-body modes are included to analyze of body-freedom flutter of the joined-wing aircraft. Several parametric studies were performed to determine the most important parameters that affect the aeroelastic behavior of a joined-wing aircraft. The special feature of a joined-wing aircraft is body-freedom flutter involving frequency interaction of the first elastic mode and the aircraft short period mode. In most parametric study cases, the body-freedom flutter speed was less than the cantilever flutter speed that is independent of fuselage inertia. As fuselage pitching moment of inertia was increased, the body-freedom flutter speed increased. When the pitching moment of inertia reaches a critical value, transition from body-freedom flutter to cantilever flutter occurred. The effects of composite laminate orientation on the front and rear wings of a joined-wing configuration were studied. An aircraft pitch divergence mode, which occurred because of forward movement of center of pressure due to wing deformation, was found. Body-freedom flutter and cantilever-like flutter were also found depending on combination of front and rear wing ply orientations. Optimized wing weight behaviors of the planar and non-planar configurations with isotropic and composite materials were investigated. Wing weight optimization of the composite joined-wing result in less weight compared to the metallic wing. Fuselage flexibility affects joined-wing flutter characteristics. Elastic mode shapes of the wing were affected by fuselage deformation and change the flutter speeds compared to the rigid fuselage. Body-freedom flutter speeds decrease as fuselage flexibility increases. Optimum wing weights increase as fuselage flexibility increases. Flutter analysis of a box wing configuration investigated the effects of center of gravity location and pitch moment of inertia on flutter speed.
Joining of SiC parts by polishing and hipping
Rossi, Guilio A.; Pelletier, Paul J.
1990-05-15
A method of joining two pre-sintered pieces of silicon carbide is disclosed. It entails polishing the surfaces to be joined to a mirror-finish, fitting the polished surfaces together to form a composite structure, and then subjecting the composite structure to hot isostatic pressing under conditions which are sufficient to form a joint which is essentially indistinguishable from the original silicon carbide pieces.
Federal Register 2010, 2011, 2012, 2013, 2014
2012-04-16
... with multiple bowls that are joined through a welding operation to form one unit are covered by the... bowls that are joined through a welding operation to form one unit are covered by the scope of the... sinks with multiple drawn bowls that are joined through a welding operation to form one unit are covered...
DeJonghe, Lutgard; Jacobson, Craig; Tucker, Michael; Visco, Steven
2013-01-01
Tubular objects having two or more concentric layers that have different properties are joined to one another during their manufacture primarily by compressive and friction forces generated by shrinkage during sintering and possibly mechanical interlocking. It is not necessary for the concentric tubes to display adhesive-, chemical- or sinter-bonding to each other in order to achieve a strong bond. This facilitates joining of dissimilar materials, such as ceramics and metals.
Joining of porous silicon carbide bodies
Bates, Carl H.; Couhig, John T.; Pelletier, Paul J.
1990-05-01
A method of joining two porous bodies of silicon carbide is disclosed. It entails utilizing an aqueous slip of a similar silicon carbide as was used to form the porous bodies, including the sintering aids, and a binder to initially join the porous bodies together. Then the composite structure is subjected to cold isostatic pressing to form a joint having good handling strength. Then the composite structure is subjected to pressureless sintering to form the final strong bond. Optionally, after the sintering the structure is subjected to hot isostatic pressing to further improve the joint and densify the structure. The result is a composite structure in which the joint is almost indistinguishable from the silicon carbide pieces which it joins.
Automated Program Recognition.
1987-02-01
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Efficient and Scalable Graph Similarity Joins in MapReduce
Chen, Yifan; Zhang, Weiming; Tang, Jiuyang
2014-01-01
Along with the emergence of massive graph-modeled data, it is of great importance to investigate graph similarity joins due to their wide applications for multiple purposes, including data cleaning, and near duplicate detection. This paper considers graph similarity joins with edit distance constraints, which return pairs of graphs such that their edit distances are no larger than a given threshold. Leveraging the MapReduce programming model, we propose MGSJoin, a scalable algorithm following the filtering-verification framework for efficient graph similarity joins. It relies on counting overlapping graph signatures for filtering out nonpromising candidates. With the potential issue of too many key-value pairs in the filtering phase, spectral Bloom filters are introduced to reduce the number of key-value pairs. Furthermore, we integrate the multiway join strategy to boost the verification, where a MapReduce-based method is proposed for GED calculation. The superior efficiency and scalability of the proposed algorithms are demonstrated by extensive experimental results. PMID:25121135
Efficient and scalable graph similarity joins in MapReduce.
Chen, Yifan; Zhao, Xiang; Xiao, Chuan; Zhang, Weiming; Tang, Jiuyang
2014-01-01
Along with the emergence of massive graph-modeled data, it is of great importance to investigate graph similarity joins due to their wide applications for multiple purposes, including data cleaning, and near duplicate detection. This paper considers graph similarity joins with edit distance constraints, which return pairs of graphs such that their edit distances are no larger than a given threshold. Leveraging the MapReduce programming model, we propose MGSJoin, a scalable algorithm following the filtering-verification framework for efficient graph similarity joins. It relies on counting overlapping graph signatures for filtering out nonpromising candidates. With the potential issue of too many key-value pairs in the filtering phase, spectral Bloom filters are introduced to reduce the number of key-value pairs. Furthermore, we integrate the multiway join strategy to boost the verification, where a MapReduce-based method is proposed for GED calculation. The superior efficiency and scalability of the proposed algorithms are demonstrated by extensive experimental results.
Tungsten foil laminate for structural divertor applications - Joining of tungsten foils
NASA Astrophysics Data System (ADS)
Reiser, Jens; Rieth, Michael; Möslang, Anton; Dafferner, Bernhard; Hoffmann, Jan; Mrotzek, Tobias; Hoffmann, Andreas; Armstrong, D. E. J.; Yi, Xiaoou
2013-05-01
This paper is the fourth in our series on tungsten laminates. The aim of this paper is to discuss laminate synthesis, meaning the joining of tungsten foils. It is obvious that the properties of the tungsten laminate strongly depend on the combination of (i) interlayer and (ii) joining technology, as this combination defines (i) the condition of the tungsten foil after joining (as-received or recrystallised) as well as (ii) the characteristics of the interface between the tungsten foil and the interlayer (wettability or diffusion leading to a solid solution or the formation of intermetallics). From the example of tungsten laminates joined by brazing with (i) an eutectic silver copper brazing filler, (ii) copper, (iii) titanium, and (iv) zirconium, the microstructure will be discussed, with special focus on the interface. Based on our assumptions of the mechanism of the extraordinary ductility of tungsten foil we present three syntheses strategies and make recommendations for the synthesis of high temperature tungsten laminates.
NASA Astrophysics Data System (ADS)
Drossel, Welf-Guntram; Schubert, Andreas; Putz, Matthias; Koriath, Hans-Joachim; Wittstock, Volker; Hensel, Sebastian; Pierer, Alexander; Müller, Benedikt; Schmidt, Marek
2018-01-01
The technique joining by forming allows the structural integration of piezoceramic fibers into locally microstructured metal sheets without any elastic interlayers. A high-volume production of the joining partners causes in statistical deviations from the nominal dimensions. A numerical simulation on geometric process sensitivity shows that the deviations have a high significant influence on the resulting fiber stresses after the joining by forming operation and demonstrate the necessity of a monitoring concept. On this basis, the electromechanical behavior of piezoceramic array transducers is investigated experimentally before, during and after the joining process. The piezoceramic array transducer consists of an arrangement of five electrical interconnected piezoceramic fibers. The findings show that the impedance spectrum depends on the fiber stresses and can be used for in-process monitoring during the joining process. Based on the impedance values the preload state of the interconnected piezoceramic fibers can be specifically controlled and a fiber overload.
Yancopoulos, G D; Blackwell, T K; Suh, H; Hood, L; Alt, F W
1986-01-31
We have recently proposed that a common recombinase performs all of the many variable region gene assembly events in B and T cells, and that the specificity of these joining events is mediated by regulating the "accessibility" of the involved gene segments. To test this possibility, we have introduced "accessible" T cell receptor (TCR) variable region gene segments into a pre-B cell line capable of recombining endogenous and transfected immunoglobulin (Ig) variable region gene segments. Although the corresponding "inaccessible" endogenous TCR gene segments do not rearrange in this line or in B cells in general, the introduced TCR gene segments join very frequently and, in fact, closely resemble introduced Ig gene segments in their recombination characteristics. These observations suggest a new role for conventional Ig transcriptional enhancers--recombinational enhancement. Our studies provide insight into additional aspects of the joining mechanism such as N region insertion, aberrant joining, and recombination-recognition sequence requirements for joining.
Corrosion behaviour of friction-bit-joined and weld-bonded AA7075-T6/galvannealed DP980
Lim, Yong Chae; Squires, Lile; Pan, Tsung-Yu; ...
2016-12-22
Joining of aluminium alloys 7075-T6 and galvannealed dual phase 980 steel was achieved by friction bit joining (FBJ) and weld-bonding (FBJ + adhesive) processes. Accelerated laboratory-scale corrosion tests were performed on both FBJ only and weld-bonded specimens to study joint strength under a corrosive environment. Static lap shear tests showed that both FBJ only and weld-bonded cases generally retained more than 80% of the joint strength of non-corroded specimens at the end of corrosion testing. The presence of Zn/Fe coating on the steel substrate resulted in improved corrosion resistance for FBJ specimens, compared to joints produced with bare steel. Finally,more » an optical microscopy was used for cross-sectional analysis of corroded specimens. Some corrosion on the joining bit was observed near the bit head. However, the joining bit was still intact on the steel substrate, indicating that the primary bond was sound.« less
Corrosion behaviour of friction-bit-joined and weld-bonded AA7075-T6/galvannealed DP980
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lim, Yong Chae; Squires, Lile; Pan, Tsung-Yu
Joining of aluminium alloys 7075-T6 and galvannealed dual phase 980 steel was achieved by friction bit joining (FBJ) and weld-bonding (FBJ + adhesive) processes. Accelerated laboratory-scale corrosion tests were performed on both FBJ only and weld-bonded specimens to study joint strength under a corrosive environment. Static lap shear tests showed that both FBJ only and weld-bonded cases generally retained more than 80% of the joint strength of non-corroded specimens at the end of corrosion testing. The presence of Zn/Fe coating on the steel substrate resulted in improved corrosion resistance for FBJ specimens, compared to joints produced with bare steel. Finally,more » an optical microscopy was used for cross-sectional analysis of corroded specimens. Some corrosion on the joining bit was observed near the bit head. However, the joining bit was still intact on the steel substrate, indicating that the primary bond was sound.« less
Laser-induced Self-organizing Microstructures on Steel for Joining with Polymers
NASA Astrophysics Data System (ADS)
van der Straeten, Kira; Burkhardt, Irmela; Olowinsky, Alexander; Gillner, Arnold
The combination of different materials such as thermoplastic composites and metals is an important way to improve lightweight construction. As direct connections between these materials fail due to their physical and chemical properties, other joining techniques are required. A new joining approach besides fastening and adhesive joining is a laser-based two-step process. Within the first step the metal surface is modified by laser-microstructuring. In order to enlarge the boundary surface and create undercuts, random self-organizing microstructures are generated on stainless steel substrates. In a second process step both joining partners, metal and composite, are clamped together, the steel surface is heated up with laser radiation and through heat conduction the thermoplastic matrix is melted and flows into the structures. After cooling-down a firm joint between both materials is created. The presented work shows the influence of different laser parameters on the generation of the microstructures. The joint strength is investigated through tensile shear strength tests.
Joining of Gamma Titanium Aluminides
2002-09-01
AFRL-ML-WP-TR-2003-4036 JOINING OF GAMMA TITANIUM ALUMINIDES LTC William A. Baeslack, III Metals Branch (AFRL/MLLM) Metals, Ceramics, and...GAMMA TITANIUM ALUMINIDES 5c. PROGRAM ELEMENT NUMBER 62102F 5d. PROJECT NUMBER MO2R 5e. TASK NUMBER 10 6. AUTHOR(S) LTC William A...comparatively discusses the results of research and development performed on the joining of gamma titanium aluminides during the past two decades. Although
Individual Factors Motivating People to Join Organized Violent Movements
2017-06-09
INDIVIDUAL FACTORS MOTIVATING PEOPLE TO JOIN ORGANIZED VIOLENT MOVEMENTS A thesis presented to the Faculty of the U.S...2016 – JUN 2017 4. TITLE AND SUBTITLE Individual Factors Motivating People to Join Organized Violent Movements 5a. CONTRACT NUMBER 5b. GRANT...NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) U.S. Army Command and General Staff College ATTN: ATZL-SWD-GD Fort Leavenworth, KS 66027
Human Factors Considerations of Undergrounds in Insurgencies
1966-09-01
personal advantage. Another may join because of a " bandwagon " effect ; if the movement is succeeding, he may join because, others join or because he...or wrong. Emotional appeals, outweighing the rational ones, tend to reinforce the bandwagon effect . Threats Threats also have been effective ...by the terror-stricken widow and children," who still have the written death sentence. "The bandwagon effect sought in these cases is to convince
Concept for a fast analysis method of the energy dissipation at mechanical joints
NASA Astrophysics Data System (ADS)
Wolf, Alexander; Brosius, Alexander
2017-10-01
When designing hybrid parts and structures one major challenge is the design, production and quality assessment of the joining points. While the polymeric composites themselves have excellent material properties, the necessary joints are often the weak link in assembled structures. This paper presents a method of measuring and analysing the energy dissipation at mechanical joining points of hybrid parts. A simplified model is applied based on the characteristic response to different excitation frequencies and amplitudes. The dissipation from damage is the result of relative moments between joining partners und damaged fibres within the composite, whereas the visco-elastic material behaviour causes the intrinsic dissipation. The ambition is to transfer these research findings to the characterisation of mechanical joints in order to quickly assess the general quality of the joint with this non-destructive testing method. The inherent challenge for realising this method is the correct interpretation of the measured energy dissipation and its attribution to either a bad joining point or intrinsic material properties. In this paper the authors present the concept for energy dissipation measurements at different joining points. By inverse analysis a simplified fast semi-analytical model will be developed that allows for a quick basic quality assessment of a given joining point.
Schimmel, Joost; Kool, Hanneke; van Schendel, Robin; Tijsterman, Marcel
2017-12-15
Cells employ potentially mutagenic DNA repair mechanisms to avoid the detrimental effects of chromosome breaks on cell survival. While classical non-homologous end-joining (cNHEJ) is largely error-free, alternative end-joining pathways have been described that are intrinsically mutagenic. Which end-joining mechanisms operate in germ and embryonic cells and thus contribute to heritable mutations found in congenital diseases is, however, still largely elusive. Here, we determined the genetic requirements for the repair of CRISPR/Cas9-induced chromosomal breaks of different configurations, and establish the mutational consequences. We find that cNHEJ and polymerase theta-mediated end-joining (TMEJ) act both parallel and redundant in mouse embryonic stem cells and account for virtually all end-joining activity. Surprisingly, mutagenic repair by polymerase theta (Pol θ, encoded by the Polq gene) is most prevalent for blunt double-strand breaks (DSBs), while cNHEJ dictates mutagenic repair of DSBs with protruding ends, in which the cNHEJ polymerases lambda and mu play minor roles. We conclude that cNHEJ-dependent repair of DSBs with protruding ends can explain de novo formation of tandem duplications in mammalian genomes. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.
IJA: an efficient algorithm for query processing in sensor networks.
Lee, Hyun Chang; Lee, Young Jae; Lim, Ji Hyang; Kim, Dong Hwa
2011-01-01
One of main features in sensor networks is the function that processes real time state information after gathering needed data from many domains. The component technologies consisting of each node called a sensor node that are including physical sensors, processors, actuators and power have advanced significantly over the last decade. Thanks to the advanced technology, over time sensor networks have been adopted in an all-round industry sensing physical phenomenon. However, sensor nodes in sensor networks are considerably constrained because with their energy and memory resources they have a very limited ability to process any information compared to conventional computer systems. Thus query processing over the nodes should be constrained because of their limitations. Due to the problems, the join operations in sensor networks are typically processed in a distributed manner over a set of nodes and have been studied. By way of example while simple queries, such as select and aggregate queries, in sensor networks have been addressed in the literature, the processing of join queries in sensor networks remains to be investigated. Therefore, in this paper, we propose and describe an Incremental Join Algorithm (IJA) in Sensor Networks to reduce the overhead caused by moving a join pair to the final join node or to minimize the communication cost that is the main consumer of the battery when processing the distributed queries in sensor networks environments. At the same time, the simulation result shows that the proposed IJA algorithm significantly reduces the number of bytes to be moved to join nodes compared to the popular synopsis join algorithm.
IJA: An Efficient Algorithm for Query Processing in Sensor Networks
Lee, Hyun Chang; Lee, Young Jae; Lim, Ji Hyang; Kim, Dong Hwa
2011-01-01
One of main features in sensor networks is the function that processes real time state information after gathering needed data from many domains. The component technologies consisting of each node called a sensor node that are including physical sensors, processors, actuators and power have advanced significantly over the last decade. Thanks to the advanced technology, over time sensor networks have been adopted in an all-round industry sensing physical phenomenon. However, sensor nodes in sensor networks are considerably constrained because with their energy and memory resources they have a very limited ability to process any information compared to conventional computer systems. Thus query processing over the nodes should be constrained because of their limitations. Due to the problems, the join operations in sensor networks are typically processed in a distributed manner over a set of nodes and have been studied. By way of example while simple queries, such as select and aggregate queries, in sensor networks have been addressed in the literature, the processing of join queries in sensor networks remains to be investigated. Therefore, in this paper, we propose and describe an Incremental Join Algorithm (IJA) in Sensor Networks to reduce the overhead caused by moving a join pair to the final join node or to minimize the communication cost that is the main consumer of the battery when processing the distributed queries in sensor networks environments. At the same time, the simulation result shows that the proposed IJA algorithm significantly reduces the number of bytes to be moved to join nodes compared to the popular synopsis join algorithm. PMID:22319375
Preliminary design optimization of joined-wing aircraft
NASA Technical Reports Server (NTRS)
Gallman, John W.; Kroo, Ilan M.; Smith, Stephen C.
1990-01-01
The joined wing is an innovative aircraft configuration that has a its tail connected to the wing forming a diamond shape in both top and plan view. This geometric arrangement utilizes the tail for both pitch control and as a structural support for the wing. Several researchers have studied this configuration and predicted significant reductions in trimmed drag or structural weight when compared with a conventional T-tail configuration. Kroo et al. compared the cruise drag of joined wings with conventional designs of the same lifting-surface area and structural weight. This study showed an 11 percent reduction in cruise drag for the lifting system of a joined wing. Although this reduction in cruise drag is significant, a complete design study is needed before any economic savings can be claimed for a joined-wing transport. Mission constraints, such as runway length, could increase the wing area and eliminate potential drag savings. Since other design codes do not accurately represent the interaction between structures and aerodynamics for joined wings, we developed a new design code for this study. The aerodynamic and structural analyses in this study are significantly more sophisticated than those used in most conventional design codes. This sophistication was needed to predict the aerodynamic interference between the wing and tail and the stresses in the truss-like structure. This paper describes these analysis methods, discusses some problems encountered when applying the numerical optimizer NPSOL, and compares optimum joined wings with conventional aircraft on the basis of cruise drag, lifting surface weight, and direct operating cost (DOC).
Yoshinari, Masao; Uzawa, Shinobu; Komiyama, Yataro
2016-10-01
The aim of this in vitro study was to evaluate tensile bond strengths and corrosion resistance of CoCr alloys joined with gold cylinder by a soldering system in comparison with the conventional cast-joining system. CoCr alloys joined with gold cylinder by a soldering system using a high-fusing gold solder (CoCr/Solder/Gold cylinder), gold alloy joined with gold cylinder by a cast joining system (Gold alloy/Gold cylinder) and CoCr castings were fabricated. The tensile bond strength and corrosion resistance in 0.9% NaCl solution (pH 7.4 and pH 2.3) were evaluated. Scanning electron microscopy (SEM) of the fractured surface and electron probe microanalysis (EPMA) of the joined interfaces were also performed. The tensile bond strengths of the CoCr/Solder/Gold cylinder specimens showed similar values as the Gold alloy/Gold cylinder specimens. SEM observation and EPMA analyses suggested firm bonding between the CoCr alloy and gold cylinder. The released elements from the CoCr/Solder/Gold cylinder specimens were similar to ones from CoCr castings. Results showed that superstructures made of CoCr alloys joined with the gold cylinder using a high-fusing gold solder had sufficient bond strength and high corrosion resistance. These hybrid frameworks with cobalt-chromium alloy and gold cylinder are promising prosthesis for implant superstructures with the low cost and favorable mechanical properties instead of conventional high-gold alloys. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.
Muleta, Muluken G; Schausberger, Peter
2013-09-01
Group-living animals frequently have to trade off the costs and benefits of leaving an established group and joining another group. Owing to their high fitness relevance, group-joining decisions are commonly nonrandom and may be based on traits of both individual members and the group such as life stage, body size, social status and group density or size, respectively. Many group-living animals are able to recognize and to associate preferentially with familiar individuals, i.e. those encountered before. Hence, after dispersing from established groups, animals commonly have to decide whether to join a new familiar or unfamiliar group. Using binary choice situations we assessed the effects of social familiarity on group-joining behaviour of the plant-inhabiting predatory mite Phytoseiulus persimilis . Group living in P. persimilis is brought about by the patchy distribution of its spider mite prey and mutual conspecific attraction. In the first experiment, gravid predator females given a choice between spider mite patches occupied by unfamiliar and familiar groups of females strongly preferred to join familiar groups and to deposit their eggs in these patches. Preference for socially familiar groups was robust across biases of spider mite prey densities between choice options. The second experiment revealed that the predatory mite females can smell social familiarity from a distance. Females subjected to odour choice situations in artificial cages were more strongly attracted to the odour of familiar than unfamiliar groups. We argue that P. persimilis females preferentially join socially familiar groups because a familiar social environment relaxes competition and optimizes foraging and reproduction.
Muleta, Muluken G.; Schausberger, Peter
2013-01-01
Group-living animals frequently have to trade off the costs and benefits of leaving an established group and joining another group. Owing to their high fitness relevance, group-joining decisions are commonly nonrandom and may be based on traits of both individual members and the group such as life stage, body size, social status and group density or size, respectively. Many group-living animals are able to recognize and to associate preferentially with familiar individuals, i.e. those encountered before. Hence, after dispersing from established groups, animals commonly have to decide whether to join a new familiar or unfamiliar group. Using binary choice situations we assessed the effects of social familiarity on group-joining behaviour of the plant-inhabiting predatory mite Phytoseiulus persimilis. Group living in P. persimilis is brought about by the patchy distribution of its spider mite prey and mutual conspecific attraction. In the first experiment, gravid predator females given a choice between spider mite patches occupied by unfamiliar and familiar groups of females strongly preferred to join familiar groups and to deposit their eggs in these patches. Preference for socially familiar groups was robust across biases of spider mite prey densities between choice options. The second experiment revealed that the predatory mite females can smell social familiarity from a distance. Females subjected to odour choice situations in artificial cages were more strongly attracted to the odour of familiar than unfamiliar groups. We argue that P. persimilis females preferentially join socially familiar groups because a familiar social environment relaxes competition and optimizes foraging and reproduction. PMID:24027341
Panchakshari, Rohit A; Zhang, Xuefei; Kumar, Vipul; Du, Zhou; Wei, Pei-Chi; Kao, Jennifer; Dong, Junchao; Alt, Frederick W
2018-01-23
Ig heavy chain (IgH) class switch recombination (CSR) in B lymphocytes switches IgH constant regions to change antibody functions. CSR is initiated by DNA double-strand breaks (DSBs) within a donor IgH switch (S) region and a downstream acceptor S region. CSR is completed by fusing donor and acceptor S region DSB ends by classical nonhomologous end-joining (C-NHEJ) and, in its absence, by alternative end-joining that is more biased to use longer junctional microhomologies (MHs). Deficiency for DSB response (DSBR) factors, including ataxia telangiectasia-mutated (ATM) and 53BP1, variably impair CSR end-joining, with 53BP1 deficiency having the greatest impact. However, studies of potential impact of DSBR factor deficiencies on MH-mediated CSR end-joining have been technically limited. We now use a robust DSB joining assay to elucidate impacts of deficiencies for DSBR factors on CSR and chromosomal translocation junctions in primary mouse B cells and CH12F3 B-lymphoma cells. Compared with wild-type, CSR and c-myc to S region translocation junctions in the absence of 53BP1, and, to a lesser extent, other DSBR factors, have increased MH utilization; indeed, 53BP1-deficient MH profiles resemble those associated with C-NHEJ deficiency. However, translocation junctions between c-myc DSB and general DSBs genome-wide are not MH-biased in ATM-deficient versus wild-type CH12F3 cells and are less biased in 53BP1- and C-NHEJ-deficient cells than CSR junctions or c-myc to S region translocation junctions. We discuss potential roles of DSBR factors in suppressing increased MH-mediated DSB end-joining and features of S regions that may render their DSBs prone to MH-biased end-joining in the absence of DSBR factors.
Barbi, Francisco C L; Camarini, Edevaldo T; Silva, Rafael S; Endo, Eliana H; Pereira, Jefferson R
2012-12-01
The influence of different joining techniques on passive fit at the interface structure/abutment of cobalt-chromium (Co-Cr) superstructures has not yet been clearly established. The purpose of this study was to compare 3 different techniques of joining Co-Cr superstructures by measuring the resulting marginal misfit in a simulated prosthetic assembly. A specially designed metal model was used for casting, sectioning, joining, and measuring marginal misfit. Forty-five cast bar-type superstructures were fabricated in a Co-Cr alloy and randomly assigned by drawing lots to 3 groups (n=15) according to the joining method used: conventional gas-torch brazing (G-TB), laser welding (LW), and tungsten inert gas welding (TIG). Joined specimens were assembled onto abutment analogs in the metal model with the 1-screw method. The resulting marginal misfit was measured with scanning electron microscopy (SEM) at 3 different points: distal (D), central (C), and mesial (M) along the buccal aspect of both abutments: A (tightened) and B (without screw). The Levene test was used to evaluate variance homogeneity and then the Welsch ANOVA for heteroscedastic data (α=.05). Significant differences were found on abutment A between groups G-TB and LW (P=.013) measured mesially and between groups G-TB and TIG (P=.037) measured centrally. On abutment B, significant differences were found between groups G-TB and LW (P<.001) and groups LW and TIG (P<.001) measured mesially; groups G-TB and TIG (P=.007) measured distally; and groups G-TB and TIG (P=.001) and LW and TIG (P=.007) measured centrally. The method used for joining Co-Cr prosthetic structures had an influence on the level of resulting passive fit. Structures joined by the tungsten inert gas method produced better mean results than did the brazing or laser method. Copyright © 2012 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.
The 1985 Army Experience Survey: Tabular Descriptions of First-Term Attritees. Volume 2
1986-01-01
survey receipt control and sample management systems . Data were also keyed, edited, coded, and weighted. The coding schemes developed to classify... R136 REGION OF RESIDENCE WHEN YOU JOINED ARMY. .. ................. 272-273 049 El37 U TERMS OF ACTIVE ENLISTMENT .. ........ ................ 274...272 R136 -- REGION OF RESIDENCE WHEN YOU JOINED ARMY RECODED - WHAT STATE WERE YOU LIVING IN WHEN YOU JOINED THE ARMY! (RECODED TO REGION OF RSID) I
Top scientists join Stephen Hawking at Perimeter Institute
NASA Astrophysics Data System (ADS)
Banks, Michael
2009-03-01
Nine leading researchers are to join Stephen Hawking as visiting fellows at the Perimeter Institute for Theoretical Physics in Ontario, Canada. The researchers, who include string theorists Leonard Susskind from Stanford University and Asoka Sen from the Harisch-Chandra Research Institute in India, will each spend a few months of the year at the institute as "distinguished research chairs". They will be joined by another 30 scientists to be announced at a later date.
Improving U.S. Navy Foodservice Management Training. Part 1. Evaluation of the Current System
1985-11-01
Experience in civilian foodservice before joining Navy? FAST FOOD FRANCHISE BAKERY RESTAURANT COFFEE SHOP CAFETERIA DELICATESSEN NONE WORKED AS...civilian foodservice since joining Navy? FAST FOOD FRANCHISE 12 8 BAKERY 15 5 RESTAURANT 12 18 COFFEE SHOP 8 — CAFETERIA 8 — DELICATESSEN — NONE...food service before joining the Navy? (PLEASE CHECK l^ THAT APPLY TO WHERE YOU WORKED) Fast Food Franchise Cafeteria Bakery Delieateesan
Method of forming a ceramic to ceramic joint
Cutler, Raymond Ashton; Hutchings, Kent Neal; Kleinlein, Brian Paul; Carolan, Michael Francis
2010-04-13
A method of joining at least two sintered bodies to form a composite structure, includes: providing a joint material between joining surfaces of first and second sintered bodies; applying pressure from 1 kP to less than 5 MPa to provide an assembly; heating the assembly to a conforming temperature sufficient to allow the joint material to conform to the joining surfaces; and further heating the assembly to a joining temperature below a minimum sintering temperature of the first and second sintered bodies. The joint material includes organic component(s) and ceramic particles. The ceramic particles constitute 40-75 vol. % of the joint material, and include at least one element of the first and/or second sintered bodies. Composite structures produced by the method are also disclosed.
Two-sided friction stir riveting by extrusion: A process for joining dissimilar materials
Evans, William T.; Cox, Chase D.; Strauss, Alvin M.; ...
2016-06-25
Two-sided friction stir riveting (FSR) by extrusion is an innovative process developed to rapidly, efficiently, and securely join dissimilar materials. This process extends a previously developed one sided friction stir extrusion process to create a strong and robust joint by producing a continuous, rivet-like structure through a preformed hole in one of the materials with a simultaneous, two-sided friction stir spot weld. The two-sided FSR by extrusion process securely joins the dissimilar materials together and effectively locks them in place without the use of any separate materials or fasteners. Lastly, in this paper we demonstrate the process by joining aluminummore » to steel and illustrate its potential application to automotive and aerospace manufacturing processes.« less
[Joining WHO of Republic of Korea and the projects in the 1950s].
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 for the efforts to prevent communicable disease, the WHO focused on leprosy, malaria, measles, smallpox, tuberculosis in 1950's. The First Republic could overcome the bad health condition after the Korea War successfully, supported by WHO.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pimputkar, S.M.; McCoy, J.K.; Stets, J.A.
1991-03-01
The integrity of a pipeline system is determined by its weakest links which may be the joints. Heat fusion is the most common method for joining gas distribution polyethylene (PE) piping. There are procedural, thermal, and mechanical aspects of making fusion joints. Acceptable procedural aspects, such as heater calibration and cleanliness, can be assured by rigorous training and certification of the operators. Thermal and mechanical aspects consist of specifying joining conditions such as the heater temperature, heating time, and joining pressure. In the absence of procedural errors, the strength of a fusion joint should depend on the pipe material, pipemore » dimensions, and the thermal and mechanical joining conditions. Socket heat fusion was studied both experimentally and analytically to determine how the strength of the joint varied with the conditions under which it was made. The standard tensile impact test was modified to test socket fusion joint samples in shear. The developed shear impact energy test data were found to be reliable measures of strength if the setups for conditions were meticulously identical. A parameter, termed the socket joining parameter, was found to characterize the joining conditions. It is a strong function of melt volume at the end of the heating phase, and physically, it is polyethylene transported parallel to the axis during insertion. The results for three resins are presented in the form of three nomographs. The nomographs may be used to select the required heater temperature or the heating time, for a given ambient temperature and a PE resin, to ensure a structurally sound socket heat fusion joint.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Pimputkar, S.M.; McCoy, J.K.; Stets, J.A.
1991-03-01
The integrity of a pipeline system is determined by its weakest links which may be the joints. Heat fusion is the most common method for joining gas distribution polyethylene (PE) piping. There are procedural, thermal, and mechanical aspects of making fusion joints. Acceptable procedural aspects, such as heater calibration and cleanliness, can be assured by rigorous training and certification of the operators. Thermal and mechanical aspects consist of specifying joining conditions such as the heater temperature, heating time, and joining pressure. In the absence of procedural errors, the strength of a fusion joint should depend on the pipe material, pipemore » dimensions, and the thermal and mechanical joining conditions. Socket heat fusion was studied both experimentally and analytically to determine how the strength of the joint varied with the conditions under which it was made. The standard tensile impact test was modified to test socket fusion joint samples in shear. The developed shear impact energy test data were found to be reliable measures of strength if the setup conditions were meticulously identical. A parameter, termed the socket joining parameter, was found to characterize the joining conditions. It is a strong function of melt volume at the end of the heating phase, and, physically, it is polyethylene transported parallel to the axis during insertion. The results for three resins are presented in the form of three nomographs. The nomographs may be used to select the required heater temperature or the heating time, for a given ambient temperature and a PE resin, to ensure a structurally sound socket heat fusion joint.« less
Boboila, Cristian; Jankovic, Mila; Yan, Catherine T; Wang, Jing H; Wesemann, Duane R; Zhang, Tingting; Fazeli, Alex; Feldman, Lauren; Nussenzweig, Andre; Nussenzweig, Michel; Alt, Frederick W
2010-02-16
Class switch recombination (CSR) in B lymphocytes is initiated by introduction of multiple DNA double-strand breaks (DSBs) into switch (S) regions that flank immunoglobulin heavy chain (IgH) constant region exons. CSR is completed by joining a DSB in the donor S mu to a DSB in a downstream acceptor S region (e.g., S gamma1) by end-joining. In normal cells, many CSR junctions are mediated by classical nonhomologous end-joining (C-NHEJ), which employs the Ku70/80 complex for DSB recognition and XRCC4/DNA ligase 4 for ligation. Alternative end-joining (A-EJ) mediates CSR, at reduced levels, in the absence of C-NHEJ, even in combined absence of Ku70 and ligase 4, demonstrating an A-EJ pathway totally distinct from C-NHEJ. Multiple DSBs are introduced into S mu during CSR, with some being rejoined or joined to each other to generate internal switch deletions (ISDs). In addition, S-region DSBs can be joined to other chromosomes to generate translocations, the level of which is increased by absence of a single C-NHEJ component (e.g., XRCC4). We asked whether ISD and S-region translocations occur in the complete absence of C-NHEJ (e.g., in Ku70/ligase 4 double-deficient B cells). We found, unexpectedly, that B-cell activation for CSR generates substantial ISD in both S mu and S gamma1 and that ISD in both is greatly increased by the absence of C-NHEJ. IgH chromosomal translocations to the c-myc oncogene also are augmented in the combined absence of Ku70 and ligase 4. We discuss the implications of these findings for A-EJ in normal and abnormal DSB repair.
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.
Process optimization of joining by upset bulging with local heating
NASA Astrophysics Data System (ADS)
Rusch, Michael; Almohallami, Amer; Sviridov, Alexander; Bonk, Christian; Behrens, Bernd-Arno; Bambach, Markus
2017-10-01
Joining by upset bulging is a mechanical joining method where axial load is applied to a tube to form two revolving bulges, which clamp the parts to be joined and create a force and form fit. It can be used to join tubes with other structures such as sheets, plates, tubes or profiles of the same or different materials. Other processes such as welding are often limited in joining multi-material assemblies or high-strength materials. With joining by upset bulging at room temperature, the main drawback is the possible initiation of damage (cracks) in the inner buckling zone because of high local stresses and strains. In this paper, a method to avoid the formation of cracks is introduced. Before forming the bulge the tube is locally heated by an induction coil. For the construction steel (E235+N) a maximum temperature of 700 °C was used to avoid phase transformation. For the numerical study of the process the mechanical properties of the tube material were examined at different temperatures and strain rates to determine its flow curves. A parametrical FE model was developed to simulate the bulging process with local heating. Experiments with local heating were executed and metallographic studies of the bulging area were conducted. While specimens heated to 500 °C showed small cracks left, damage-free flanges could be created at 600 and 700 °C. Static testing of damage-free bulges showed improvements in tensile strength and torsion strength compared to bulges formed at room-temperature, while bending and compression behavior remained nearly unchanged. In cyclic testing the locally heated specimens underwent about 3.7 times as many cycles before failure as the specimens formed at room temperature.
Using Negotiated Joining to Construct and Fill Open-ended Roles in Elite Culinary Groups.
Tan, Vaughn
2015-03-01
This qualitative study examines membership processes in groups operating in an uncertain environment that prevents them from fully predefining new members' roles. I describe how nine elite high-end, cutting-edge culinary groups in the U.S. and Europe, ranging from innovative restaurants to culinary R&D groups, use negotiated joining-a previously undocumented process-to systematically construct and fill these emergent, open-ended roles. I show that negotiated joining is a consistently patterned, iterative process that begins with a role that both aspirant and target group explicitly understand to be provisional. This provisional role is then jointly modified and constructed by the aspirant and target group through repeated iterations of proposition, validation through trial and evaluation, and selective integration of validated role components. The initially provisional role stabilizes and the aspirant achieves membership if enough role components are validated; otherwise the negotiated joining process is abandoned. Negotiated joining allows the aspirant and target group to learn if a mutually desirable role is likely and, if so, to construct such a role. In addition, the provisional roles in negotiated joining can support absorptive capacity by allowing novel role components to enter target groups through aspirants' efforts to construct stable roles for themselves, while the internal adjustment involved in integrating newly validated role components can have the unintended side effect of supporting adaptation by providing opportunities for the groups to use these novel role components to modify their role structure and goals to suit a changing and uncertain environment. Negotiated joining thus reveals role ambiguity's hitherto unexamined beneficial consequences and provides a foundation for a contingency theory of new-member acquisition.
Parametric weight evaluation of joined wings by structural optimization
NASA Technical Reports Server (NTRS)
Miura, Hirokazu; Shyu, Albert T.; Wolkovitch, Julian
1988-01-01
Joined-wing aircraft employ tandem wings having positive and negative sweep and dihedral, arranged to form diamond shapes in both plan and front views. An optimization method was applied to study the effects of joined-wing geometry parameters on structural weight. The lightest wings were obtained by increasing dihedral and taper ratio, decreasing sweep and span, increasing fraction of airfoil chord occupied by structural box, and locating the joint inboard of the front wing tip.
Communication Lower Bounds and Optimal Algorithms for Programs that Reference Arrays - Part 1
2013-05-14
include tensor contractions, the direct N-body algorithm, and database join. 1This indicates that this is the first of 5 times that matrix multiplication...and database join. Section 8 summarizes our results, and outlines the contents of Part 2 of this paper. Part 2 will discuss how to compute lower...contractions, the direct N–body algo- rithm, database join, and computing matrix powers Ak. 2 Geometric Model We begin by reviewing the geometric
Joining Pipe with the Hybrid Laser-GMAW Process: Weld Test Results and Cost Analysis
2006-06-01
Recent work investigating the poten- tial benefit of applying this technology to a shipyard pipe shop suggests that signifi- cant cost savings may be...arc-based joining processes. With recent advances in com- mercial laser technology , laser suppliers can now deliver dramatically higher power systems...reasons, shipyards in the U.S. are showing growing interest in hybrid laser-GMA welding technology . Hybrid Laser-GMA for Joining Pipe Welding of pipe
Connecting the Dots: Enduring Challenges in the Nation’s Information Sharing Environment
2010-05-12
mails describes an exchange in which Major Hassan wrote, “I can’t wait to join you” in the afterlife . 113...Hassan’s email: ‘I Can’t Wait to Join You’ in Afterlife ,” ABC News, (November 19, 2009). http://abcnews.go.com/Blotter/major-hasans-mail-wait-join... afterlife /story?id=9130339 (accessed January 12, 2010). 112Senate and Homeland Security and Governmental Affairs Committee, Statement by Juan Carlos
Joining and Integration of Silicon Carbide-Based Materials for High Temperature Applications
NASA Technical Reports Server (NTRS)
Halbig, Michael C.; Singh, Mrityunjay
2016-01-01
Advanced joining and integration technologies of silicon carbide-based ceramics and ceramic matrix composites are enabling for their implementation into wide scale aerospace and ground-based applications. The robust joining and integration technologies allow for large and complex shapes to be fabricated and integrated with the larger system. Potential aerospace applications include lean-direct fuel injectors, thermal actuators, turbine vanes, blades, shrouds, combustor liners and other hot section components. Ground based applications include components for energy and environmental systems. Performance requirements and processing challenges are identified for the successful implementation different joining technologies. An overview will be provided of several joining approaches which have been developed for high temperature applications. In addition, various characterization approaches were pursued to provide an understanding of the processing-microstructure-property relationships. Microstructural analysis of the joint interfaces was conducted using optical, scanning electron, and transmission electron microscopy to identify phases and evaluate the bond quality. Mechanical testing results will be presented along with the need for new standardized test methods. The critical need for tailoring interlayer compositions for optimum joint properties will also be highlighted.
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NASA Astrophysics Data System (ADS)
The present conference on advances in joining novel structural materials encompasses such material types as ceramics, plastics and composites, and new metallic materials. Specific issues addressed include the use of conductor electric explosion to join ceramics, the effects of brazing temperature on joint properties of SiC-fiber-reinforced Al-alloy-matrix composites, the in situ structure control of composite materials, and the weldability of polymeric materials that are heterogeneous as to chemical nature from the standpoint of morphology. Also addressed are the joining of the Al-Li alloy 8090, diffusion bonding of a creep-resistant Fe-ODS alloy, the adhesive bonding of zinc-coated steel sheets, welds in thermoplastic composite materials, and hot-melt joints for carbon-fiber-reinforced composites.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Rabin, B.H.
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 themore » 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.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
GLASS, S. JILL; LOEHMAN, RONALD E.; HOSKING, F. MICHAEL
The main objective of this project was to develop reliable, low-cost techniques for joining silicon nitride (Si{sub 3}N{sub 4}) to itself and to metals. For Si{sub 3}N{sub 4} to be widely used in advanced turbomachinery applications, joining techniques must be developed that are reliable, cost-effective, and manufacturable. This project addressed those needs by developing and testing two Si{sub 3}N{sub 4} joining systems; oxynitride glass joining materials and high temperature braze alloys. Extensive measurements were also made of the mechanical properties and oxidation resistance of the braze materials. Finite element models were used to predict the magnitudes and positions of themore » stresses in the ceramic regions of ceramic-to-metal joints sleeve and butt joints, similar to the geometries used for stator assemblies.« less
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Patriarca, P.; Slaughter, G.M.
1962-11-27
A method of joining metal surfaces is given. Surfaces having nickel or iron as the base metal are joined together with a brazing composition consisting of 80% nickel, 10% phosphorus, and 10% chromium. (AEC)
Method for in vitro recombination
Gibson, Daniel Glenn; Smith, Hamilton O
2013-05-07
The present invention relates to an in vitro method, using isolated protein reagents, for joining two double-stranded (ds) DNA molecules of interest, wherein the distal region of the first DNA molecule and the proximal region of the second DNA molecule share a region of sequence identity. The method allows the joining of a number of DNA fragments, in a predetermined order and orientation, without the use of restriction enzymes. It can be used, e.g., to join synthetically produced sub-fragments of a gene or genome of interest.
Low temperature reactive bonding
Makowiecki, D.M.; Bionta, R.M.
1995-01-17
The joining technique is disclosed that requires no external heat source and generates very little heat during joining. It involves the reaction of thin multilayered films deposited on faying surfaces to create a stable compound that functions as an intermediate or braze material in order to create a high strength bond. While high temperatures are reached in the reaction of the multilayer film, very little heat is generated because the films are very thin. It is essentially a room temperature joining process. 5 figures.
Astronaut Sullivan prepares to join crew in training
1984-09-04
41D-3188 (2 September 1984) --- Astronaut Kathryn D. Sullivan, 41-G mission specialist, joins with other members of the seven-person crew prior to a training session in the Shuttle mockup and integration laboratory at the Johnson Space Center. Dr. Sullivan will be the first American woman to perform an extravehicular activity (EVA) in space when she joins Astronaut David C. Leestma for some outside-the-Challenger duty on October 9. The mission is scheduled for an October 5, 1984 launch.
Internet Radicalization: Actual Threat or Phantom Menace?
2012-09-01
in Afterlife ,” abcnews.go.com, November 19, 2009, http://abcnews.go.com/Blotter/major-hasans-mail-wait-join- afterlife /story?id=9130339#.T28z6XjnsfM...Rhonda Schwartz. “Major Hasan’s E-Mail: ‘I Can’t Wait to Join You’ in Afterlife .” abcnews.go.com. November 19, 2009. http://abcnews.go.com/Blotter...major-hasans-mail-wait-join- afterlife /story?id=9130339#.T28z6XjnsfM. Rucker, Philip, and Julie Tate. “In Online Posts Apparently by Detroit Suspect
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Improved Joining of Metal Components to Composite Structures
NASA Technical Reports Server (NTRS)
Semmes, Edmund
2009-01-01
Systems requirements for complex spacecraft drive design requirements that lead to structures, components, and/or enclosures of a multi-material and multifunctional design. The varying physical properties of aluminum, tungsten, Invar, or other high-grade aerospace metals when utilized in conjunction with lightweight composites multiply system level solutions. These multi-material designs are largely dependent upon effective joining techAn improved method of joining metal components to matrix/fiber composite material structures has been invented. The method is particularly applicable to equipping such thin-wall polymer-matrix composite (PMC) structures as tanks with flanges, ceramic matrix composite (CMC) liners for high heat engine nozzles, and other metallic-to-composite attachments. The method is oriented toward new architectures and distributing mechanical loads as widely as possible in the vicinities of attachment locations to prevent excessive concentrations of stresses that could give rise to delaminations, debonds, leaks, and other failures. The method in its most basic form can be summarized as follows: A metal component is to be joined to a designated attachment area on a composite-material structure. In preparation for joining, the metal component is fabricated to include multiple studs projecting from the aforementioned face. Also in preparation for joining, holes just wide enough to accept the studs are molded into, drilled, or otherwise formed in the corresponding locations in the designated attachment area of the uncured ("wet') composite structure. The metal component is brought together with the uncured composite structure so that the studs become firmly seated in the holes, thereby causing the composite material to become intertwined with the metal component in the joining area. Alternately, it is proposed to utilize other mechanical attachment schemes whereby the uncured composite and metallic parts are joined with "z-direction" fasteners. The resulting "wet" assembly is then subjected to the composite-curing heat treatment, becoming a unitary structure. It should be noted that this new art will require different techniques for CMC s versus PMC's, but the final architecture and companion curing philosophy is the same. For instance, a chemical vapor infiltration (CVI) fabrication technique may require special integration of the pre-form and
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46 CFR 56.15-1 - Pipe joining fittings.
Code of Federal Regulations, 2013 CFR
2013-10-01
... subpart 50.25 of this subchapter are acceptable for use in piping systems. (b) Threaded, flanged, socket-welding, buttwelding, and socket-brazing pipe joining fittings, made in accordance with the applicable...
46 CFR 56.15-1 - Pipe joining fittings.
Code of Federal Regulations, 2011 CFR
2011-10-01
... subpart 50.25 of this subchapter are acceptable for use in piping systems. (b) Threaded, flanged, socket-welding, buttwelding, and socket-brazing pipe joining fittings, made in accordance with the applicable...
46 CFR 56.15-1 - Pipe joining fittings.
Code of Federal Regulations, 2014 CFR
2014-10-01
... subpart 50.25 of this subchapter are acceptable for use in piping systems. (b) Threaded, flanged, socket-welding, buttwelding, and socket-brazing pipe joining fittings, made in accordance with the applicable...
46 CFR 56.15-1 - Pipe joining fittings.
Code of Federal Regulations, 2012 CFR
2012-10-01
... subpart 50.25 of this subchapter are acceptable for use in piping systems. (b) Threaded, flanged, socket-welding, buttwelding, and socket-brazing pipe joining fittings, made in accordance with the applicable...
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International Rett Syndrome Foundation
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Splicing Efficiently Couples Optical Fibers
NASA Technical Reports Server (NTRS)
Lutes, G. F.
1985-01-01
Method of splicing single-mode optical fibers results in very low transmission losses through joined fiber ends. Coupling losses between joined optical-fiber ends only 0.1 dB. Method needs no special operator training.
49 CFR 192.283 - Plastic pipe: Qualifying joining procedures.
Code of Federal Regulations, 2011 CFR
2011-10-01
... Materials Other Than by Welding § 192.283 Plastic pipe: Qualifying joining procedures. (a) Heat fusion... for making plastic pipe joints by a heat fusion, solvent cement, or adhesive method, the procedure...
49 CFR 192.283 - Plastic pipe: Qualifying joining procedures.
Code of Federal Regulations, 2013 CFR
2013-10-01
... Materials Other Than by Welding § 192.283 Plastic pipe: Qualifying joining procedures. (a) Heat fusion... for making plastic pipe joints by a heat fusion, solvent cement, or adhesive method, the procedure...
49 CFR 192.283 - Plastic pipe: Qualifying joining procedures.
Code of Federal Regulations, 2014 CFR
2014-10-01
... Materials Other Than by Welding § 192.283 Plastic pipe: Qualifying joining procedures. (a) Heat fusion... for making plastic pipe joints by a heat fusion, solvent cement, or adhesive method, the procedure...
49 CFR 192.283 - Plastic pipe: Qualifying joining procedures.
Code of Federal Regulations, 2012 CFR
2012-10-01
... Materials Other Than by Welding § 192.283 Plastic pipe: Qualifying joining procedures. (a) Heat fusion... for making plastic pipe joints by a heat fusion, solvent cement, or adhesive method, the procedure...
American Academy of Neurological and Orthopaedic Surgeons
... standards through peer review and continuous medical education. Meetings Join us for our Annual Scientific Meeting, in ... seeks to provide its qualified members with the... Meetings Meetings Join us for our Annual Scientific Meeting, ...
Proctor, John P.
2001-02-27
A duct joining system for providing an air-tight seal and mechanical connection for ducts and fittings is disclosed. The duct joining system includes a flexible gasket affixed to a male end of a duct or fitting. The flexible gasket is affixed at an angle relative to normal of the male end of the duct. The female end of the other duct includes a raised bead in which the flexible gasket is seated when the ducts are properly joined. The angled flexible gasket seated in the raised bead forms an air-tight seal as well as fastens or locks the male end to the female end. Alternatively, when a flexible duct is used, a band clamp with a raised bead is clamped over the female end of the flexible duct and over the male end of a fitting to provide an air tight seal and fastened connection.
Proctor, John P.; deKieffer, Robert C.
2001-01-01
A duct joining system for providing an air-tight seal and mechanical connection for ducts and fittings is disclosed. The duct joining system includes a flexible gasket affixed to a male end of a duct or fitting. The flexible gasket is affixed at an angle relative to normal of the male end of the duct. The female end of the other duct includes a raised bead in which the flexible gasket is seated when the ducts are properly joined. The angled flexible gasket seated in the raised bead forms an air-tight seal as well as fastens or locks the male end to the female end. Alternatively, when a flexible duct is used, a band clamp with a raised bead is clamped over the female end of the flexible duct and over the male end of a fitting to provide an air tight seal and fastened connection.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Ma, Ying; Li, Hong; Bridges, Denzel
We report that the continuing miniaturization of microelectronics is pushing advanced manufacturing into nanomanufacturing. Nanojoining is a bottom-up assembly technique that enables functional nanodevice fabrication with dissimilar nanoscopic building blocks and/or molecular components. Various conventional joining techniques have been modified and re-invented for joining nanomaterials. Our review surveys recent progress in nanojoining methods, as compared to conventional joining processes. Examples of nanojoining are given and classified by the dimensionality of the joining materials. At each classification, nanojoining is reviewed and discussed according to materials specialties, low dimensional processing features, energy input mechanisms and potential applications. The preparation of new intermetallicmore » materials by reactive nanoscale multilayer foils based on self-propagating high-temperature synthesis is highlighted. This review will provide insight into nanojoining fundamentals and innovative applications in power electronics packaging, plasmonic devices, nanosoldering for printable electronics, 3D printing and space manufacturing.« less
Visovsky, Constance; Beedy, Dianne Morrison-
2016-12-01
Joining Forces is a comprehensive national initiative within the United States to mobilize all sectors of society to give service members and their families the opportunities and support they have earned. This national initiative begun in April 2012 was led by First Lady Michelle Obama and Dr. Jill Biden. The Joining Forces initiative is charged with enhancing the well-being and psychological health of the military family by providing mental health care services, integrating community-based services to reduce homelessness, substance abuse for veterans and military families. This manuscript addresses how one university with its global partners joined together to host an innovative conference addressing the research, education, and practice needs of healthcare professionals caring for military, veterans, and their families. Copyright © 2016 Elsevier Ltd. All rights reserved.
Design, Fabrication and Characterization of High Temperature Joints in Ceramic Composites
NASA Technical Reports Server (NTRS)
Singh, M.
1999-01-01
Ceramic joining has been recognized as one of the enabling technologies for the successful utilization of ceramic components in a number of demanding, high temperature applications. Various joint design philosophies and design issues have been discussed along with an affordable, robust ceramic joining technology (ARCJoinT). A wide variety of silicon carbide-based composite materials, in different shapes and sizes, have been joined using this technology. This technique is capable of producing joints with tailorable thickness and composition. The room and high temperature mechanical properties and fractography of ceramic joints have been reported. These joints maintain their mechanical strength up to 1200 C in air. This technology is suitable for the joining of large and complex shaped ceramic composite components and with certain modifications, can be applied to repair of ceramic components damaged in service.
Design, Fabrication, and Characterization of High Temperature Joints in Ceramic Composites
NASA Technical Reports Server (NTRS)
Singh, M.
1999-01-01
Ceramic joining has been recognized as one of the enabling technologies for the successful utilization of ceramic components in a number of demanding, high temperature applications. Various joint design philosophies and design issues have been discussed along with an affordable, robust ceramic joining technology (ARCJoinT). A wide variety of silicon carbide-based composite materials, in different shapes and sizes, have been joined using this technology. This technique is capable of producing joints with tailorable thickness and composition. The room and high temperature mechanical properties and fractography of ceramic joints have been reported. These joints maintain their mechanical strength up to 1200C in air. This technology is suitable for the joining of large and complex shaped ceramic composite components and with certain modifications, can be applied to repair of ceramic components damaged in service.
Laser Transmission Welding of CFRTP Using Filler Material
NASA Astrophysics Data System (ADS)
Berger, Stefan; Schmidt, Michael
In the automotive industry the increasing environmental awareness is reflected through consistent lightweight construction. Especially the use of carbon fiber reinforced thermoplastics (CFRTP) plays an increasingly important role. Accordingto the material substitution, the demand for adequate joining technologies is growing. Therefore, laser transmission welding with filler material provides a way to combine two opaque joining partners by using process specific advantages of the laser transmission welding process. After introducing the new processing variant and the used experimental setup, this paper investigates the process itselfand conditions for a stable process. The influence of the used process parameters on weld quality and process stability is characterized by tensile shear tests. The successfully performed joining of PA 6 CF 42 organic sheets using natural PA 6 as filler material underlines the potential of the described joining method for lightweight design and other industrial applications.
Application of the joined wing to tiltrotor aircraft
NASA Technical Reports Server (NTRS)
Wolkovitch, Julian; Wainfan, Barnaby; Ben-Harush, Yitzhak; Johnson, Wayne
1989-01-01
A study was made to determine the potential speed improvements and other benefits resulting from the application of the joined wing concept to tiltrotor aircraft. Using the XV-15 as a baseline, the effect of replacing the cantilever wing by a joined-wing pair was studied. The baseline XV-15 cantilever wing has a thickness/chord ratio of 23 percent. It was found that this wing could be replaced by a joined-wing pair of the same span and total area employing airfoils of 12 percent thickness/chord ratio. The joined wing meets the same static strength requirements as the cantilever wing, but increases the limiting Mach Number of the aircraft from M=0.575 to M=0.75, equivalent to an increase of over 100 knots in maximum speed. The joined wing configuration studied is lighter than the cantilever and has approximately 11 percent less wing drag in cruise. Its flutter speed of 245 knots EAS is not high enough to allow the potential Mach number improvement to be attained at low altitude. The flutter speed can be raised either by employing rotors which can be stopped and folded in flight at speeds below 245 knots EAS, or by modifying the airframe to reduce adverse coupling with the rotor dynamics. Several modifications of wing geometry and nacelle mass distribution were investigated, but none produced a flutter speed above 260 knots EAS. It was concluded that additional research is required to achieve a more complete understanding of the mechanism of rotor/wing coupling.
Munich, Stephan A; Tan, Lee A; Nogueira, Danilo M; Keigher, Kiffon M; Chen, Michael; Crowley, R Webster; Conners, James J; Lopes, Demetrius K
2017-09-01
The primary correlate to survival and preservation of neurologic function in patients suffering from an acute ischemic stroke is time from symptom onset to initiation of therapy and reperfusion. Communication and coordination among members of the stroke team are essential to maximizing efficiency and subsequently early reperfusion. In this work, we aim to describe our preliminary experience using the Join mobile application as a means to improve interdisciplinary team communication and efficiency. We describe our pilot experience with the initiation of the Join mobile application between July 2015 and July 2016. With this application, a mobile beacon is transported with the patient on the ambulance. Transportation milestone timestamps and geographic coordinates are transmitted to the treating facility and instantly communicated to all treatment team members. The transport team / patient can be tracked en route to the treating facility. During our pilot study, 62 patients were triaged and managed using the Join application. Automated time-stamping of critical events, geographic tracking of patient transport and summary documents were obtained for all patients. Treatment team members had an overall favorable impression of the Join application and recommended its continued use. The Join application is one of several components of a multi-institutional, interdisciplinary effort to improve the treatment of patients with acute ischemic stroke. The ability of the treatment team to track patient transport and communicate with the transporting team may improve reperfusion time and, therefore, improve neurologic outcomes.
Biochemical evidence for Ku-independent backup pathways of NHEJ.
Wang, Huichen; Perrault, Ange Ronel; Takeda, Yoshihiko; Qin, Wei; Wang, Hongyan; Iliakis, George
2003-09-15
Cells of higher eukaryotes process within minutes double strand breaks (DSBs) in their genome using a non-homologous end joining (NHEJ) apparatus that engages DNA-PKcs, Ku, DNA ligase IV, XRCC4 and other as of yet unidentified factors. Although chemical inhibition, or mutation, in any of these factors delays processing, cells ultimately remove the majority of DNA DSBs using an alternative pathway operating with an order of magnitude slower kinetics. This alternative pathway is active in mutants deficient in genes of the RAD52 epistasis group and frequently joins incorrect ends. We proposed, therefore, that it reflects an alternative form of NHEJ that operates as a backup (B-NHEJ) to the DNA-PK-dependent (D-NHEJ) pathway, rather than homology directed repair of DSBs. The present study investigates the role of Ku in the coordination of these pathways using as a model end joining of restriction endonuclease linearized plasmid DNA in whole cell extracts. Efficient, error-free, end joining observed in such in vitro reactions is strongly inhibited by anti-Ku antibodies. The inhibition requires DNA-PKcs, despite the fact that Ku efficiently binds DNA ends in the presence of antibodies, or in the absence of DNA-PKcs. Strong inhibition of DNA end joining is also mediated by wortmannin, an inhibitor of DNA-PKcs, in the presence but not in the absence of Ku, and this inhibition can be rescued by pre-incubating the reaction with double stranded oligonucleotides. The results are compatible with a role of Ku in directing end joining to a DNA-PK dependent pathway, mediated by efficient end binding and productive interactions with DNA-PKcs. On the other hand, efficient end joining is observed in extracts of cells lacking DNA-PKcs, as well as in Ku-depleted extracts in line with the operation of alternative pathways. Extracts depleted of Ku and DNA-PKcs rejoin blunt ends, as well as homologous ends with 3' or 5' protruding single strands with similar efficiency, but addition of Ku suppresses joining of blunt ends and homologous ends with 3' overhangs. We propose that the affinity of Ku for DNA ends, particularly when cooperating with DNA-PKcs, suppresses B-NHEJ by quickly and efficiently binding DNA ends and directing them to D-NHEJ for rapid joining. A chromatin-based model of DNA DSB rejoining accommodating biochemical and genetic results is presented and deviations between in vitro and in vivo results discussed.
Biochemical evidence for Ku-independent backup pathways of NHEJ
Wang, Huichen; Perrault, Ange Ronel; Takeda, Yoshihiko; Qin, Wei; Wang, Hongyan; Iliakis, George
2003-01-01
Cells of higher eukaryotes process within minutes double strand breaks (DSBs) in their genome using a non-homologous end joining (NHEJ) apparatus that engages DNA-PKcs, Ku, DNA ligase IV, XRCC4 and other as of yet unidentified factors. Although chemical inhibition, or mutation, in any of these factors delays processing, cells ultimately remove the majority of DNA DSBs using an alternative pathway operating with an order of magnitude slower kinetics. This alternative pathway is active in mutants deficient in genes of the RAD52 epistasis group and frequently joins incorrect ends. We proposed, therefore, that it reflects an alternative form of NHEJ that operates as a backup (B-NHEJ) to the DNA-PK-dependent (D-NHEJ) pathway, rather than homology directed repair of DSBs. The present study investigates the role of Ku in the coordination of these pathways using as a model end joining of restriction endonuclease linearized plasmid DNA in whole cell extracts. Efficient, error-free, end joining observed in such in vitro reactions is strongly inhibited by anti-Ku antibodies. The inhibition requires DNA-PKcs, despite the fact that Ku efficiently binds DNA ends in the presence of antibodies, or in the absence of DNA-PKcs. Strong inhibition of DNA end joining is also mediated by wortmannin, an inhibitor of DNA-PKcs, in the presence but not in the absence of Ku, and this inhibition can be rescued by pre-incubating the reaction with double stranded oligonucleotides. The results are compatible with a role of Ku in directing end joining to a DNA-PK dependent pathway, mediated by efficient end binding and productive interactions with DNA-PKcs. On the other hand, efficient end joining is observed in extracts of cells lacking DNA-PKcs, as well as in Ku-depleted extracts in line with the operation of alternative pathways. Extracts depleted of Ku and DNA-PKcs rejoin blunt ends, as well as homologous ends with 3′ or 5′ protruding single strands with similar efficiency, but addition of Ku suppresses joining of blunt ends and homologous ends with 3′ overhangs. We propose that the affinity of Ku for DNA ends, particularly when cooperating with DNA-PKcs, suppresses B-NHEJ by quickly and efficiently binding DNA ends and directing them to D-NHEJ for rapid joining. A chromatin-based model of DNA DSB rejoining accommodating biochemical and genetic results is presented and deviations between in vitro and in vivo results discussed. PMID:12954774
Joined-wing research airplane feasibility study
NASA Technical Reports Server (NTRS)
Wolkovitch, J.
1984-01-01
The joined wing is a new type of aircraft configuration which employs tandem wings arranged to form diamond shapes in plan view and front view. Wind-tunnel tests and finite-element structural analyses have shown that the joined wing provides the following advantages over a comparable wing-plus-tail system; lighter weight and higher stiffness, higher span-efficiency factor, higher trimmed maximum lift coefficient, lower wave drag, plus built-in direct lift and direct sideforce control capability. To verify these advantages at full scale a manned research airplane is required. A study has therefore been performed of the feasibility of constructing such an airplane, using the fuselage and engines of the existing NAA AD-1 oblique-wing airplane. Cost and schedule constraints favored converting the AD-1 rather than constructing a totally new airframe. By removing the outboard wing panels the configuration can simulate wings joined at 60, 80, or 100 percent of span. For maximum versatility the aircraft has alternative control surfaces (such as ailerons and elevators on the front and/or rear wings), and a removeable canard to explore canard/joined-wing interactions at high-lift conditions. Design, performance, and flying qualities are discussed.
Histone H1 functions as a stimulatory factor in backup pathways of NHEJ
Rosidi, Bustanur; Wang, Minli; Wu, Wenqi; Sharma, Aparna; Wang, Huichen; Iliakis, George
2008-01-01
DNA double-strand breaks (DSBs) induced in the genome of higher eukaryotes by ionizing radiation (IR) are predominantly removed by two pathways of non-homologous end-joining (NHEJ) termed D-NHEJ and B-NHEJ. While D-NHEJ depends on the activities of the DNA-dependent protein kinase (DNA-PK) and DNA ligase IV/XRCC4/XLF, B-NHEJ utilizes, at least partly, DNA ligase III/XRCC1 and PARP-1. Using in vitro end-joining assays and protein fractionation protocols similar to those previously applied for the characterization of DNA ligase III as an end-joining factor, we identify here histone H1 as an additional putative NHEJ factor. H1 strongly enhances DNA-end joining and shifts the product spectrum from circles to multimers. While H1 enhances the DNA-end-joining activities of both DNA Ligase IV and DNA Ligase III, the effect on ligase III is significantly stronger. Histone H1 also enhances the activity of PARP-1. Since histone H1 has been shown to counteract D-NHEJ, these observations and the known functions of the protein identify it as a putative alignment factor operating preferentially within B-NHEJ. PMID:18250087
Expert system for adhesive selection of composite material joints
DOE Office of Scientific and Technical Information (OSTI.GOV)
Allen, R.B.; Vanderveldt, H.H.
The development of composite joining is still in its infancy and much is yet to be learned. Consequently, this field is developing rapidly and new advances occur with great regularity. The need for up-to-date information and expertise in engineering and planning of composite materials, especially in critical applications, is acute. The American Joining Institute`s (AJI) development of JOINEXCELL (an off-line intelligent planner for joining composite materials) is an intelligent engineering/planning software system that incorporates the knowledge of several experts which can be expanded as these developments occur. Phase I effort of JOINEXCELL produced an expert system for adhesive selection, JOINADSELECT,more » for composite material joints. The expert system successfully selects from over 26 different adhesive families for 44 separate material types and hundreds of application situations. Through a series of design questions the expert system selects the proper adhesive for each particular design. Performing this {open_quotes}off-line{close_quotes} engineering planning by computer allows the decision to be made with full knowledge of the latest information about materials and joining procedures. JOINADSELECT can greatly expedite the joining design process, thus yielding cost savings.« less
Embedded Heaters for Joining or Separating Plastic Parts
NASA Technical Reports Server (NTRS)
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.
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TRANSFORMER FOR JOINING UNBALANCED TO BALANCED TRANSMISSION MEANS
Bittner, B.J.; Opperman, R.H.
1960-06-28
An improved transformer is invented for joining an unbalanced transmission means to a balanced transmission means and is useful, for example, in transmitting an electromagnetic signal from a coaxial cable to a balanced dipole antenna.
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Liquid-solid joining of bulk metallic glasses
NASA Astrophysics Data System (ADS)
Huang, Yongjiang; Xue, Peng; Guo, Shu; Wu, Yang; Cheng, Xiang; Fan, Hongbo; Ning, Zhiliang; Cao, Fuyang; Xing, Dawei; Sun, Jianfei; Liaw, Peter K.
2016-07-01
Here, we successfully welded two bulk metallic glass (BMG) materials, Zr51Ti5Ni10Cu25Al9 and Zr50.7Cu28Ni9Al12.3 (at. %), using a liquid-solid joining process. An atomic-scale metallurgical bonding between two BMGs can be achieved. The interface has a transition layer of ~50 μm thick. The liquid-solid joining of BMGs can shed more insights on overcoming their size limitation resulting from their limited glass-forming ability and then promoting their applications in structural components.
Liquid-solid joining of bulk metallic glasses
Huang, Yongjiang; Xue, Peng; Guo, Shu; Wu, Yang; Cheng, Xiang; Fan, Hongbo; Ning, Zhiliang; Cao, Fuyang; Xing, Dawei; Sun, Jianfei; Liaw, Peter K.
2016-01-01
Here, we successfully welded two bulk metallic glass (BMG) materials, Zr51Ti5Ni10Cu25Al9 and Zr50.7Cu28Ni9Al12.3 (at. %), using a liquid-solid joining process. An atomic-scale metallurgical bonding between two BMGs can be achieved. The interface has a transition layer of ~50 μm thick. The liquid-solid joining of BMGs can shed more insights on overcoming their size limitation resulting from their limited glass-forming ability and then promoting their applications in structural components. PMID:27471073
Liquid-solid joining of bulk metallic glasses.
Huang, Yongjiang; Xue, Peng; Guo, Shu; Wu, Yang; Cheng, Xiang; Fan, Hongbo; Ning, Zhiliang; Cao, Fuyang; Xing, Dawei; Sun, Jianfei; Liaw, Peter K
2016-07-29
Here, we successfully welded two bulk metallic glass (BMG) materials, Zr51Ti5Ni10Cu25Al9 and Zr50.7Cu28Ni9Al12.3 (at. %), using a liquid-solid joining process. An atomic-scale metallurgical bonding between two BMGs can be achieved. The interface has a transition layer of ~50 μm thick. The liquid-solid joining of BMGs can shed more insights on overcoming their size limitation resulting from their limited glass-forming ability and then promoting their applications in structural components.
Fluxing agent for metal cast joining
Gunkel, Ronald W.; Podey, Larry L.; Meyer, Thomas N.
2002-11-05
A method of joining an aluminum cast member to an aluminum component. The method includes the steps of coating a surface of an aluminum component with flux comprising cesium fluoride, placing the flux coated component in a mold, filling the mold with molten aluminum alloy, and allowing the molten aluminum alloy to solidify thereby joining a cast member to the aluminum component. The flux preferably includes aluminum fluoride and alumina. A particularly preferred flux includes about 60 wt. % CsF, about 30 wt. % AlF.sub.3, and about 10 wt. % Al.sub.2 O.sub.3.
Liquid-solid joining of bulk metallic glasses
Huang, Yongjiang; Xue, Peng; Guo, Shu; ...
2016-07-29
Here, we successfully welded two bulk metallic glass (BMG) materials, Zr 51Ti 5Ni 10Cu 25Al 9 and Zr 50.7Cu 28Ni 9Al 12.3 (at. %), using a liquid-solid joining process. An atomic-scale metallurgical bonding between two BMGs can be achieved. The interface has a transition layer of ~50 μm thick. In conclusion, the liquid-solid joining of BMGs can shed more insights on overcoming their size limitation resulting from their limited glass-forming ability and then promoting their applications in structural components.
Gao, Wei; Vander Sande, John B.
1998-01-01
A method is provided for fabrication of superconducting oxides and superconducting oxide composites and for joining superconductors to other materials. A coating of a molten alloy containing the metallic elements of the oxide is applied to a substrate surface and oxidized to form the superconducting oxide. A material can be contacted to the molten alloy which is subsequently oxidized joining the material to the resulting superconducting oxide coating. Substrates of varied composition and shape can be coated or joined by this method.
Gao, W.; Vander Sande, J.B.
1998-07-28
A method is provided for fabrication of superconducting oxides and superconducting oxide composites and for joining superconductors to other materials. A coating of a molten alloy containing the metallic elements of the oxide is applied to a substrate surface and oxidized to form the superconducting oxide. A material can be contacted to the molten alloy which is subsequently oxidized joining the material to the resulting superconducting oxide coating. Substrates of varied composition and shape can be coated or joined by this method. 5 figs.
Joining of Silicon Carbide-Based Ceramics by Reaction Forming Method
NASA Technical Reports Server (NTRS)
Singh, M.; Kiser, J. D.
1997-01-01
Recently, there has been a surge of interest in the development and testing of silicon-based ceramics and composite components for a number of aerospace and ground based systems. The designs often require fabrication of complex shaped parts which can be quite expensive. One attractive way of achieving this goal is to build up complex shapes by joining together geometrically simple shapes. However, the joints should have good mechanical strength and environmental stability comparable to the bulk materials. These joints should also be able to maintain their structural integrity at high temperatures. In addition, the joining technique should be practical, reliable, and affordable. Thus, joining has been recognized as one of the enabling technologies for the successful utilization of silicon carbide based ceramic components in high temperature applications. Overviews of various joining techniques, i.e., mechanical fastening, adhesive bonding, welding, brazing, and soldering have been provided in recent publications. The majority of the techniques used today are based on the joining of monolithic ceramics with metals either by diffusion bonding, metal brazing, brazing with oxides and oxynitrides, or diffusion welding. These techniques need either very high temperatures for processing or hot pressing (high pressures). The joints produced by these techniques have different thermal expansion coefficients than the ceramic materials, which creates a stress concentration in the joint area. The use temperatures for these joints are around 700 C. Ceramic joint interlayers have been developed as a means of obtaining high temperature joints. These joint interlayers have been produced via pre-ceramic polymers, in-situ displacement reactions, and reaction bonding techniques. Joints produced by the pre-ceramic polymer approach exhibit a large amounts of porosity and poor mechanical properties. On the other hand, hot pressing or high pressures are needed for in-situ displacement reactions and reaction bonding techniques. Due to the equipment required, these techniques are impractical for joining large or complex shaped components.
Joining of thin glass with semiconductors by ultra-fast high-repetition laser welding
NASA Astrophysics Data System (ADS)
Horn, Alexander; Mingaeev, Ilja; Werth, Alexander; Kachel, Martin
2008-02-01
Lighting applications like OLED or on silicon for electro-optical applications need a reproducible sealing process. The joining has to be strong, the permeability for gasses and humidity very low and the process itself has to be very localized not affecting any organic or electronic parts inside the sealed region. The actual sealing process using glue does not fulfil these industrial needs. A new joining process using ultra-fast laser radiation offers a very precise joining with geometry dimensions smaller than 50 μm. Ultra-fast laser radiation is absorbed by multi-photon absorption in the glass. Due to the very definite threshold for melting and ablation the process of localized heating can be controlled without cracking. Repeating the irradiation at times smaller than the heat diffusion time the temperature in the focus is increased by heat accumulation reaching melting of the glass. Mowing the substrate relatively to the laser beam generates a seal of re-solidified glass. Joining of glass is achieved by positioning the laser focus at the interface. A similar approach is used for glass-silicon joining. The investigations presented will demonstrate the joining geometry by microscopy of cross-sections achieved by welding two glass plates (Schott D263 and AF45) with focused IR femtosecond laser radiation (wavelength λ = 1045nm, repetition rate f = 1 MHz, pulse duration t p = 500 fs, focus diameter w 0 = 4 μm, feeding velocity v= 1-10 mm/s). The strength of the welding seam is measured by tensile stress measurements and the gas and humidity is detected. A new diagnostic method for the on-line detection of the welding seam properties will be presented. Using a non-interferometric technique by quantitative phase microscopy the refractive index is measured during welding of glass in the time regime 0-2 μs. By calibration of the measured refractive index with a relation between refractive index and temperature a online-temperature detection can be achieved.
75 FR 8746 - Certain Steel Grating From China
Federal Register 2010, 2011, 2012, 2013, 2014
2010-02-25
... sheet or thin plate steel that has been slit and expanded, and does not involve welding or joining of..., that has been pierced and cold formed, and does not involve welding or joining of multiple pieces of...
33 CFR 166.500 - Areas along the Atlantic Coast.
Code of Federal Regulations, 2010 CFR
2010-07-01
... Fairway. The area enclosed by rhumb lines, [North American Datum of 1927 (NAD-27)] joining points at...″ W (ii) Nantucket to Ambrose Safety Fairway. The area enclosed by rhumb lines, NAD-27, joining point...
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NASA Astrophysics Data System (ADS)
Loehman, Ronald E.
Methods for joining ceramics are outlined with attention given to their fundamental properties, and some examples of ceramic bonding in engineering ceramic systems are presented. Ceramic-ceramic bonds using no filler material include diffusion and electric-field bonding and ceramic welding, and bonds with filler materials can be provided by Mo-Mn brazing, microwave joining, and reactive nonmetallic liquid bonding. Ceramic-metal joints can be effected with filler material by means of the same ceramic-ceramic processes and without filler material by means of use of molten glass or diffusion bonding. Key properties of the bonding processes include: bonds with discontinuous material properties, energies that are positive relative to the bulk material, and unique chemical and mechanical properties. The processes and properties are outlined for ceramic-metal joints and for joining silicon nitride, and the factors that control wetting, adhesion, and reaction on the atomic scale are critical for establishing successful joints.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Henager, Charles H.; Kurtz, Richard J.; Canfield, Nathan L.
The use of SiC composites in fusion environments likely requires joining of plates using reactive joining or brazing. One promising reactive joining method uses solid-state displacement reactions between Si and TiC to produce Ti3SiC2 + SiC. We continue to explore the processing envelope for this joint for the TITAN collaboration in order to produce optimal joints to undergo irradiation studies in HFIR. One noted feature of the joints produced using tape-calendared powders of TiC+Si has been the large void regions that have been apparently unavoidable. Although the produced joints are very strong, these voids are undesirable. In addition, the tapesmore » that were made for this joining were produced about 20 years ago and were aging. Therefore, we embarked on an effort to produce some new tape cast powders of TiC and Si that could replace our aging tape calendared materials.« less
Explosive Spot Joining of Metals
NASA Technical Reports Server (NTRS)
Bement, Laurence J. (Inventor); Perry, Ronnie B. (Inventor)
1997-01-01
The invention is an apparatus and method for wire splicing using an explosive joining process. The apparatus consists of a prebend, U-shaped strap of metal that slides over prepositioned wires. A standoff means separates the wires from the strap before joining. An adhesive means holds two ribbon explosives in position centered over the U-shaped strap. A detonating means connects to the ribbon explosives. The process involves spreading strands of each wire to be joined into a flat plane. The process then requires alternating each strand in alignment to form a mesh-like arrangement with an overlapped area. The strap slides over the strands of the wires. and the standoff means is positioned between the two surfaces. The detonating means then initiates the ribbon explosives that drive the strap to accomplish a high velocity. angular collision between the mating surfaces. This collision creates surface melts and collision bonding resulting in electron-sharing linkups.
One ring to bring them all--the role of Ku in mammalian non-homologous end joining.
Grundy, Gabrielle J; Moulding, Hayley A; Caldecott, Keith W; Rulten, Stuart L
2014-05-01
The repair of DNA double strand breaks is essential for cell survival and several conserved pathways have evolved to ensure their rapid and efficient repair. The non-homologous end joining pathway is initiated when Ku binds to the DNA break site. Ku is an abundant nuclear heterodimer of Ku70 and Ku80 with a toroidal structure that allows the protein to slide over the broken DNA end and bind with high affinity. Once locked into placed, Ku acts as a tool-belt to recruit multiple interacting proteins, forming one or more non-homologous end joining complexes that act in a regulated manner to ensure efficient repair of DNA ends. Here we review the structure and functions of Ku and the proteins with which it interacts during non-homologous end joining. Copyright © 2014 Elsevier B.V. All rights reserved.
Permanent wire splicing by an explosive joining process
NASA Technical Reports Server (NTRS)
Bement, Laurence J. (Inventor); Kushnick, Anne C. (Inventor)
1991-01-01
The invention is an apparatus and method for wire splicing using an explosive joining process. The apparatus consists of a prebent, U-shaped strap of metal that slides over prepositioned wires. A standoff means separates the wires from the strap before joining. An adhesive means holds two ribbon explosives in position centered over the U-shaped strap. A detonating means connects to the ribbon explosives. The process involves spreading strands of each wire to be joined into a flat plane. The process then requires alternating each strand in alignment to form a mesh-like arrangement with an overlapped area. The strap slides over the strands of the wires, and the standoff means is positioned between the two surfaces. The detonating means then initiates the ribbon explosives that drive the strap to accomplish a high velocity, angular collision between the mating surfaces. This collision creates surface melts and collision bonding results in electron sharing linkups.
NASA Technical Reports Server (NTRS)
Ahmed, Rafiq (Inventor); Wingate, Robert J. (Inventor)
2005-01-01
In the aerospace field spacecraft components are held together by separation systems until a specific time when they must be separated or deployed. Customarily a threaded joining bolt engages one of the components to be joined, and a threaded nut is placed on that bolt against the other component so they can be drawn together by a releasable locking assembly. The releasable locking assembly herein includes a plunger having one end coupled to one end of a plunger bolt. The other end is flanged to abut and compress a coil spring when the plunger is advanced toward the interface plane between the two components. When the plunger is so advanced toward the interface plane, the end of the plunger bolt can be connected to the joining bolt. Thus during retraction the joining bolt is drawn to one side of the interface plane by the force of the expanding spring.
NASA Technical Reports Server (NTRS)
Ahmed, Rafiq (Inventor); Wingate, Robert J. (Inventor)
2005-01-01
In the aerospace field spacecraft components are held together by separation systems until a specific time when they must be separated or deployed. Customarily a threaded joining bolt engages one of the components to be joined, and a threaded nut is placed on that bolt against the other component so they can be drawn together by a releasable locking assembly. The releasable locking assembly herein includes a plunger having one end coupled to one end of a plunger bolt. The other end is flanged to abut and compress a coil spring when the plunger is advanced toward the interface plane between the two components. When the plunger is so advanced toward the interface plane, the end of the plunger bolt can be connected to the joining bolt. Thus during retraction the joining bolt is drawn to one side of the interface plane by the force of the expanding spring.
Low temperature joining of ceramic composites
Barton, Thomas J.; Anderson, Iver E.; Ijadi-Maghsoodi, Sina; Nosrati, Mohammad; Unal, Ozer
1999-01-12
A method of joining similar or dissimilar ceramic and ceramic composite materials, such as SiC continuous fiber ceramic composites, at relatively low joining temperatures uses a solventless, three component bonding agent effective to promote mechanical bond toughness and elevated temperature strength to operating temperatures of approximately 1200 degrees C. The bonding agent comprises a preceramic precursor, an aluminum bearing powder, such as aluminum alloy powder, and mixtures of aluminum metal or alloy powders with another powder, and and boron powder in selected proportions. The bonding agent is disposed as an interlayer between similar or dissimilar ceramic or cermaic composite materials to be joined and is heated in ambient air or inert atmosphere to a temperature not exceeding about 1200 degrees C. to form a strong and tough bond joint between the materials. The bond joint produced is characterized by a composite joint microstructure having relatively soft, compliant aluminum bearing particulate regions dispersed in a ceramic matrix.
Low temperature joining of ceramic composites
Barton, Thomas J.; Anderson, Iver E.; Ijadi-Maghsoodi, Sina; Nosrati, Mohammad; Unal, Ozer
1999-07-13
A method of joining similar or dissimilar ceramic and ceramic composite materials, such as SiC continuous fiber ceramic composites, at relatively low joining temperatures uses a solventless, three component bonding agent effective to promote mechanical bond toughness and elevated temperature strength to operating temperatures of approximately 1200 degrees C. The bonding agent comprises a preceramic precursor, an aluminum bearing powder, such as aluminum alloy powder, and mixtures of aluminum metal or alloy powders with another powder, and and boron powder in selected proportions. The bonding agent is disposed as an interlayer between similar or dissimilar ceramic or ceramic composite materials to be joined and is heated in ambient air or inert atmosphere to a temperature not exceeding about 1200 degrees C. to form a strong and tough bond joint between the materials. The bond joint produced is characterized by a composite joint microstructure having relatively soft, compliant aluminum bearing particulate regions dispersed in a ceramic matrix.
Low temperature joining of ceramic composites
Barton, Thomas J.; Anderson, Iver E.; Ijadi-Maghsoodi, Sina; Nosrati, Mohammad; Unal, Ozer
2001-04-10
A method of joining similar or dissimilar ceramic and ceramic composite materials, such as SiC continuous fiber ceramic composites, at relatively low joining temperatures uses a solventless, three component bonding agent effective to promote mechanical bond toughness and elevated temperature strength to operating temperatures of approximately 1200 degrees C. The bonding agent comprises a preceramic precursor, an aluminum bearing powder, such as aluminum alloy powder, and mixtures of aluminum metal or alloy powders with another powder, and and boron powder in selected proportions. The bonding agent is disposed as an interlayer between similar or dissimilar ceramic or cermaic composite materials to be joined and is heated in ambient air or inert atmosphere to a temperature not exceeding about 1200 degrees C. to form a strong and tough bond joint between the materials. The bond joint produced is characterized by a composite joint microstructure having relatively soft, compliant aluminum bearing particulate regions dispersed in a ceramic matrix.
Low temperature joining of ceramic composites
Barton, T.J.; Anderson, I.E.; Ijadi-Maghsoodi, S.; Nosrati, M.; Unal, O.
1999-07-13
A method of joining similar or dissimilar ceramic and ceramic composite materials, such as SiC continuous fiber ceramic composites, at relatively low joining temperatures uses a solventless, three component bonding agent effective to promote mechanical bond toughness and elevated temperature strength to operating temperatures of approximately 1200 C. The bonding agent comprises a preceramic precursor, an aluminum bearing powder, such as aluminum alloy powder, and mixtures of aluminum metal or alloy powders with another powder, and boron powder in selected proportions. The bonding agent is disposed as an interlayer between similar or dissimilar ceramic or ceramic composite materials to be joined and is heated in ambient air or inert atmosphere to a temperature not exceeding about 1200 C to form a strong and tough bond joint between the materials. The bond joint produced is characterized by a composite joint microstructure having relatively soft, compliant aluminum bearing particulate regions dispersed in a ceramic matrix. 3 figs.
Low temperature joining of ceramic composites
Barton, T.J.; Anderson, I.E.; Ijadi-Maghsoodi, S.; Nosrati, M.; Unal, O.
1999-01-12
A method of joining similar or dissimilar ceramic and ceramic composite materials, such as SiC continuous fiber ceramic composites, at relatively low joining temperatures uses a solventless, three component bonding agent effective to promote mechanical bond toughness and elevated temperature strength to operating temperatures of approximately 1200 degrees C. The bonding agent comprises a preceramic precursor, an aluminum bearing powder, such as aluminum alloy powder, and mixtures of aluminum metal or alloy powders with another powder, and boron powder in selected proportions. The bonding agent is disposed as an interlayer between similar or dissimilar ceramic or ceramic composite materials to be joined and is heated in ambient air or inert atmosphere to a temperature not exceeding about 1200 degrees C. to form a strong and tough bond joint between the materials. The bond joint produced is characterized by a composite joint microstructure having relatively soft, compliant aluminum bearing particulate regions dispersed in a ceramic matrix. 3 figs.
Advances in Solid State Joining of High Temperature Alloys
NASA Technical Reports Server (NTRS)
Ding, Jeff; Schneider, Judy
2011-01-01
Many of the metals used in the oil and gas industry are difficult to fusion weld including Titanium and its alloys. Solid state joining processes are being pursued as an alternative process to produce robust structures more amenable to high pressure applications. Various solid state joining processes include friction stir welding (FSW) and a patented modification termed thermal stir welding (TSW). The configuration of TSWing utilizes an induction coil to preheat the material minimizing the burden on the weld tool extending its life. This provides the ability to precisely select and control the temperature to avoid detrimental changes to the microstructure. The work presented in this presentation investigates the feasibility of joining various titanium alloys using the solid state welding processes of FSW and TSW. Process descriptions and attributes of each weld process will be presented. Weld process set ]up and welding techniques will be discussed leading to the challenges experienced. Mechanical property data will also be presented.
NASA Astrophysics Data System (ADS)
Fedorov, Vasilii; Uhlig, Thomas; Wagner, Guntram
2017-07-01
Joining of dissimilar materials like stainless steel and aluminum is of special interest for automotive applications. Due to the different properties of these materials, suitable joining techniques are required. Brazing offers the possibilities to manufacture high performance joints in one step and at low joining temperatures. However, these joints often need to withstand a high number of high cyclic loads during application. Therefore, in addition to the monotonic properties, the fatigue behavior of the produced joints must be considered and evaluated. In the present work, specimens are manufactured by induction brazing using an AlSi10 filler and a non-corrosive flux. The mechanical properties are determined by tensile shear tests as well as in fatigue tests at ambient and elevated temperatures. The microstructure of the brazed joints and the fracture surfaces of the tested samples are investigated by SEM.
Zero-dimensional to three-dimensional nanojoining: current status and potential applications
Ma, Ying; Li, Hong; Bridges, Denzel; ...
2016-08-01
We report that the continuing miniaturization of microelectronics is pushing advanced manufacturing into nanomanufacturing. Nanojoining is a bottom-up assembly technique that enables functional nanodevice fabrication with dissimilar nanoscopic building blocks and/or molecular components. Various conventional joining techniques have been modified and re-invented for joining nanomaterials. Our review surveys recent progress in nanojoining methods, as compared to conventional joining processes. Examples of nanojoining are given and classified by the dimensionality of the joining materials. At each classification, nanojoining is reviewed and discussed according to materials specialties, low dimensional processing features, energy input mechanisms and potential applications. The preparation of new intermetallicmore » materials by reactive nanoscale multilayer foils based on self-propagating high-temperature synthesis is highlighted. This review will provide insight into nanojoining fundamentals and innovative applications in power electronics packaging, plasmonic devices, nanosoldering for printable electronics, 3D printing and space manufacturing.« less
Diffusion Bonding of Silicon Carbide for a Micro-Electro-Mechanical Systems Lean Direct Injector
NASA Technical Reports Server (NTRS)
Halbig, Michael C.; Singh, Mrityunjay; Shpargel, Tarah P.; Kiser, James D.
2006-01-01
Robust approaches for joining silicon carbide (SiC) to silicon carbide sub-elements have been developed for a micro-electro-mechanical systems lean direct injector (MEMS LDI) application. The objective is to join SiC sub-elements to form a leak-free injector that has complex internal passages for the flow and mixing of fuel and air. Previous bonding technology relied upon silicate glass interlayers that were not uniform or leak free. In a newly developed joining approach, titanium foils and physically vapor deposited titanium coatings were used to form diffusion bonds between SiC materials during hot pressing. Microscopy results show the formation of well adhered diffusion bonds. Initial tests show that the bond strength is much higher than required for the component system. Benefits of the joining technology are fabrication of leak free joints with high temperature and mechanical capability.
Self-healing of cracks in Ag joining layer for die-attachment in power devices
NASA Astrophysics Data System (ADS)
Chen, Chuantong; Nagao, Shijo; Suganuma, Katsuaki; Jiu, Jinting; Zhang, Hao; Sugahara, Tohru; Iwashige, Tomohito; Sugiura, Kazuhiko; Tsuruta, Kazuhiro
2016-08-01
Sintered silver (Ag) joining has attracted significant interest in power devices modules for its ability to form stable joints with a porous interconnection layer. A function for the self-healing of cracks in sintered porous Ag interlayers at high temperatures is discovered and reported here. A crack which was prepared on a Ag joining layer was closed after heating at 200 °C in air. The tensile strength of pre-cracked Ag joining layer specimens recovers to the value of non-cracked specimens after heating treatment. Transmission electron microscopy (TEM) was used to probe the self-healing mechanism. TEM images and electron diffraction patterns show that a large quantity of Ag nanoparticles formed at the gap with the size less than 10 nm, which bridges the crack in the self-healing process. This discovery provides additional motivation for the application of Ag as an interconnection material for power devices at high temperature.
NASA Technical Reports Server (NTRS)
Ferguson, Robert E.; Shafirovich, Evgeny; Mantovani, James G.
2017-01-01
To mitigate dust problems during launch/landing operations in lunar and Mars missions, it is desired to build solid pads on the surface. Recently, strong tiles have been fabricated from lunar regolith simulants using high-temperature sintering. The present work investigates combustion joining of these tiles through the use of exothermic intermetallic reactions. Specifically, nickel/aluminum (1:1 mole ratio) mixture was placed in a gap between the tiles sintered from JSC-1A lunar regolith simulant. Upon ignition by a laser, a self-sustained propagation of the combustion front over the mixture occurred. Joining was improved with increasing the tile thickness from 6.3 mm to 12.7 mm. The temperatures sufficient for melting the glass phase of JSC-1A were recorded for 12.7-mm tiles, which explains the observed better joining.
NASA Technical Reports Server (NTRS)
Ferguson, Robert E.; Mantovani, James G.; Shafirovich, Evgeny
2017-01-01
To mitigate dust problems during launch-landing operations in lunar and Mars missions, it is desired to build solid pads on the surface. Recently, strong tiles have been fabricated from lunar regolith simulants using high-temperature sintering. The present work investigates combustion joining of these tiles through the use of exothermic intermetallic reactions. Specifically, nickel aluminum (1:1 mole ratio) mixture was placed in a gap between the tiles sintered from JSC-1A lunar regolith simulant. Upon ignition by a laser, a self-sustained propagation of the combustion front over the mixture occurred. Joining was improved with increasing the tile thickness from 6.3 mm to 12.7 mm. The temperatures sufficient for melting the glass phase of JSC-1A were recorded for 12.7-mm tiles, which explains the observed better joining.
Bryan, Craig J; Bryan, AnnaBelle O; Ray-Sannerud, Bobbie N; Etienne, Neysa; Morrow, Chad E
2014-04-01
Past self-injurious thoughts and behaviors (SITB) are robust predictors of future suicide risk, but no studies have explored the prevalence of SITB occurring prior to military service among military personnel and veterans, or the association of premilitary SITB with suicidal ideation and suicide attempts during or after military service. The current study explores these issues in two separate samples. Self-report data were collected from 374 college student veterans via anonymous only survey (Study 1) and from 151 military personnel receiving outpatient mental health treatment (Study 2). Across both studies, premilitary suicide attempts were among the most prominent predictor of subsequent suicide attempts that occurred after joining the military, even when controlling for demographics and more recent emotional distress. Among military personnel who made a suicide attempt during or after military service, approximately 50% across both samples experienced suicidal ideation and up to 25% made a suicide attempt prior to joining the military. Military personnel and veterans who made suicide attempts prior to joining the military were over six times more likely to make a later suicide attempt after joining the military. In Study 2, significantly more severe current suicidal ideation was reported by participants with histories of premilitary suicide risk, even when controlling for SITB occurring while in the military. Military personnel and veterans who experienced SITB, especially suicide attempts, prior to joining the military are more likely to attempt suicide while in the military and/or as a veteran, and experience more severe suicidal crises. © 2014.
Conventional and Microwave Joining of Silicon Carbide Using Displacement Reactions
NASA Technical Reports Server (NTRS)
Kingsley, J.; Yiin, T.; Barmatz, M.
1995-01-01
Microwave heating was used to join Silicon Carbide rods using a thin TiC /Si tape interlayer . Microwaves quickly heated the rods and tape to temperatures where solid-state displacement reactions between TiC and Si occurred.
NASA Technical Reports Server (NTRS)
Stein, B. A. (Compiler); Buckley, J. D. (Compiler)
1972-01-01
Various technological processes to achieve lightweight reliable joining systems for structural elements of aircraft and spacecraft are considered. Joining methods, combinations of them, and nondestructive evaluation and quality assurance are emphasized.
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49 CFR 192.283 - Plastic pipe: Qualifying joining procedures.
Code of Federal Regulations, 2010 CFR
2010-10-01
....283 Section 192.283 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Joining of...
Chord Splicing & Joining Detail; Chord & CrossBracing Joint Details; ...
Chord Splicing & Joining Detail; Chord & Cross-Bracing Joint Details; Cross Bracing Center Joint Detail; Chord & Diagonal Joint Detail - Vermont Covered Bridge, Highland Park, spanning Kokomo Creek at West end of Deffenbaugh Street (moved to), Kokomo, Howard County, IN
A new generation of high temperature oxygen sensors
NASA Astrophysics Data System (ADS)
Spirig, John V.
Potentiometric internal reference oxygen sensors were created by embedding a metal/metal oxide mixture within an yttria-stabilized zirconia oxygen-conducting ceramic superstructure. A static internal reference oxygen pressure was produced inside the reference chamber of the sensor at the target application temperature. The metal/metal oxide-containing reference chamber was sealed within the stabilized zirconia ceramic superstructure by a high pressure (3-6 MPa) and high temperature (1200-1300°C) bonding method that initiated grain boundary sliding between the ceramic components. The bonding method created ceramic joints that were pore-free and indistinguishable from the bulk ceramic. The oxygen sensor presented in this study is capable of long-term operation and is resistant to the strains of thermal cycling. The temperature ceiling of this device was limited to 800°C by the glass used to seal the sensor package where the lead wire breached the inner-to-outer environment. Were it possible to create a gas-tight joint between an electron carrier and stabilized zirconia, additional sealing agents would not be necessary during sensor construction. In order to enable this enhancement it is necessary to make a gas-tight joint between two dissimilar materials: a ceramic electrolyte and an efficient ceramic electron carrier. Aluminum-doped lanthanum strontium manganese oxide, La0.77Sr 0.20Al0.9Mn0.1O3, was joined to stabilized tetragonal zirconia polymorph YTZP (ZrO2)0.97(Y 2O3)0.03 by a uniaxial stress (3-6 MPa) and high-temperature (1250-1350°C) bonding method that initiated grain-boundary sliding between the ceramic components. An analysis of reactivity between different Al-dopings of LaxSr1-xAlyMn1-yO3 indicated that the Al:Mn ratio must be high to diminish the reaction between LaxSr1-xAlyMn1-yO3 and stabilized zirconia. While the resulting compound, La0.77Sr 0.20Al0.9Mn0.1O3, was an inefficient electron carrier, the successful bond between an aluminum-doped manganate perovskite and stabilized zirconia, served as a model system for joining electron carriers to an electrolyte without the creation of undesirable interlayers. Electron microscopy confirmed that intergranular penetration occurred at the joining plane leading to effective bonding between the two dissimilar ceramics. Raman spectral maps of the joining planes obtained with 2-D Raman microscopy demonstrated the absence of any new phases at the interface. A conducting perovskite with a lower Al:Mn ratio, but compensating A-site deficiency, La0.69Sr0.18Al0.45Mn0.55 O3, was joined to YTZP at 1250°C. X-ray diffraction was used to gain structural information on this A-site deficient perovskite. Room temperature resistivity measurements of the electroceramics were performed on joined and unjoined samples to determine the extent to which joining altered electron conduction within the LSAM. Electron microscopy confirmed that intergranular penetration occurred at the joining plane leading to effective bonding between the two dissimilar ceramics. Raman spectral maps of the joined samples demonstrated that joining temperature determines the extent to which interlayers begin to form in the joining plane. X-ray microdiffraction of the joining planes confirmed a threshold temperature for operation of a device created from these materials at 1350°C. A new material with diminished reactivity and high conductivity is presented to serve as a replacement for metal electrodes. In this manner, the model for a new generation of high-temperature oxygen sensors with internal references and ceramic wires is elucidated.
Apache Wars: A Constabulary Perspective
2005-05-26
matriarchal ; young men would join their wife’s family upon marriage. Multiple families joined into local groups, which organized primarily for common interests...designated organization to free and protect its society from subversion, lawlessness, and insurgency. Also called FID. (JP 1-02) Information
Supercomputers Join the Fight against Cancer – U.S. Department of Energy
DOE Office of Scientific and Technical Information (OSTI.GOV)
None
The Department of Energy has some of the best supercomputers in the world. Now, they’re joining the fight against cancer. Learn about our new partnership with the National Cancer Institute and GlaxoSmithKline Pharmaceuticals.
Women's Heart Disease: Join the Heart Truth Community
... this page please turn JavaScript on. Feature: Women's Heart Disease Join The Heart Truth Community Past Issues / Winter 2014 Table of Contents National Symbol The centerpiece of The Heart Truth ® is The Red Dress ® which was introduced ...
4. Close view of the logs joining of the north ...
4. Close view of the logs joining of the north and south rooms, with scale (Note: hole with remains of peg SITU as seen in the east cabin) - The Hermitage, Alfred's Cabin, 4580 Rachel's Lane, Hermitage, Davidson County, TN
DOE Office of Scientific and Technical Information (OSTI.GOV)
None
Performing a global barrier operation in a parallel computer that includes compute nodes coupled for data communications, where each compute node executes tasks, with one task on each compute node designated as a master task, including: for each task on each compute node until all master tasks have joined a global barrier: determining whether the task is a master task; if the task is not a master task, joining a single local barrier; if the task is a master task, joining the global barrier and the single local barrier only after all other tasks on the compute node have joinedmore » the single local barrier.« less
Online Education and e-Consent for GeneScreen, a Preventive Genomic Screening Study.
Cadigan, R Jean; Butterfield, Rita; Rini, Christine; Waltz, Margaret; Kuczynski, Kristine J; Muessig, Kristin; Goddard, Katrina A B; Henderson, Gail E
2017-01-01
Online study recruitment is increasingly popular, but we know little about the decision making that goes into joining studies in this manner. In GeneScreen, a genomic screening study that utilized online education and consent, we investigated participants' perceived ease when deciding to join and their understanding of key study features. Individuals were recruited via mailings that directed them to a website where they could learn more about GeneScreen, consent to participate, and complete a survey. Participants found it easy to decide to join GeneScreen and had a good understanding of study features. Multiple regression analyses revealed that ease of deciding to join was related to confidence in one's genetic self-efficacy, limited concerns about genetic screening, trust in and lack of frustration using the website, and the ability to spend a limited time on the website. Understanding of study features was related to using the Internet more frequently and attaining more information about GeneScreen conditions. The ease of deciding to join a genomic screening study and comprehension of its key features should be treated as different phenomena in research and practice. There is a need for a more nuanced understanding of how individuals respond to web-based consent information. © 2017 S. Karger AG, Basel.
NASA Astrophysics Data System (ADS)
Kramer, Thorsten; Olowinsky, Alexander M.
2003-07-01
Conventional joining techniques like press fitting or crimping require the application of mechanical forces to the parts which, in combination with the tolerances of both parts to be joined, lead to imprecision and poor tensile strength. In contrast, laser beam micro welding provides consistent joining and high flexibility and it acts as an alternative as long as press fitting, crimping, screwing or gluing are not capable of batch production. Different parts and even different metals can be joined in a non-contact process at feed rates of up to 60 m/min and with weld seam lengths from 0.6 mm to 15.7 mm. Due to the low energy input, typically 1 J to 6 J, a weld width as small as 50 μm and a weld depth as small as 20 μm have been attained. This results in low distortion of the joined watch components. Since the first applications of laser beam micro welding of watch components showed promising results, the process has further been enhanced using the SHADOW technique. Aspects of the technique such as tensile strength, geometry and precision of the weld seam as well as the acceptance amongst the -mostly conservative- watch manufacturers have been improved.
NASA Astrophysics Data System (ADS)
Wesling, V.; Treutler, K.; Bick, T.; Stonis, M.; Langner, J.; Kriwall, M.
2018-06-01
In lightweight construction, light metals like aluminum are used in addition to high-strength steels. However, a welded joint of aluminum and steel leads to the precipitation of brittle, intermetallic phases and contact corrosion. Nevertheless, to use the advantages of this combination in terms of weight saving composite hybrid forging has been developed. In this process, an aluminum solid part and a steel sheet were formed in a single step and joined at the same time with zinc as brazing material. For this purpose, the zinc was applied by hot dipping on the aluminum in order to produce a connection via this layer in a forming process, under pressure and heat. Due to the formed intermediate layer of zinc, the formation of the Fe-Al intermetallic phases and the contact corrosion are excluded. By determining the mathematical relationships between joining parameters and the connection properties the strength of a specific joint geometry could be adjusted to reach the level of conventional joining techniques. In addition to the presentation of the joint properties, the influence of the joining process on the structure of the involved materials is also shown. Furthermore, the failure behavior under static tensile and shear stress will be shown.
NASA Astrophysics Data System (ADS)
Casalegno, Valentina; Kondo, Sosuke; Hinoki, Tatsuya; Salvo, Milena; Czyrska-Filemonowicz, Aleksandra; Moskalewicz, Tomasz; Katoh, Yutai; Ferraris, Monica
2018-04-01
The aim of this work was to investigate and discuss the microstructure and interface reaction of a calcia-alumina based glass-ceramic (CA) with SiC. CA has been used for several years as a glass-ceramic for pressure-less joining of SiC based components. In the present work, the crystalline phases in the CA glass-ceramic and at the CA/SiC interface were investigated and the absence of any detectable amorphous phase was assessed. In order to provide a better understanding of the effect of irradiation on the joining material and on the joints, Si ion irradiation was performed both on bulk CA and CA joined SiC. CA glass-ceramic and CA joined SiC were both irradiated with 5.1 MeV Si2+ ions to 3.3 × 1020 ions/m2 at temperatures of 400 and 800 °C at DuET facility, Kyoto University. This corresponds to a damage level of 5 dpa for SiC averaged over the damage range. This paper presents the results of a microstructural analysis of the irradiated samples as well as an evaluation of the dimensional stability of the CA glass-ceramic and its irradiation temperature and/or damage dependence.
Investigations on laser transmission welding of absorber-free thermoplastics
NASA Astrophysics Data System (ADS)
Mamuschkin, Viktor; Olowinsky, Alexander; Britten, Simon W.; Engelmann, Christoph
2014-03-01
Within the plastic industry laser transmission welding ranks among the most important joining techniques and opens up new application areas continuously. So far, a big disadvantage of the process was the fact that the joining partners need different optical properties. Since thermoplastics are transparent for the radiation of conventional beam sources (800- 1100 nm) the absorbance of one of the joining partners has to be enhanced by adding an infrared absorber (IR-absorber). Until recently, welding of absorber-free parts has not been possible. New diode lasers provide a broad variety of wavelengths which allows exploiting intrinsic absorption bands of thermoplastics. The use of a proper wavelength in combination with special optics enables laser welding of two optically identical polymer parts without absorbers which can be utilized in a large number of applications primarily in the medical and food industry, where the use of absorbers usually entails costly and time-consuming authorization processes. In this paper some aspects of the process are considered as the influence of the focal position, which is crucial when both joining partners have equal optical properties. After a theoretical consideration, an evaluation is carried out based on welding trials with polycarbonate (PC). Further aspects such as gap bridging capability and the influence of thickness of the upper joining partner are investigated as well.
Prevalence of and interest in unionization among staff pharmacists.
Zgarrick, David P; McHugh, Patrick P; Droege, Marcus
2006-09-01
Although the propensity for staff pharmacists to join a labor union has never been high, conditions in the profession and workplace have changed over the last decade. Some of these changes may result in staff pharmacists joining a labor union, as well as increased interest in staff pharmacists who are currently not union members to join. The objectives of this study were to (1) assess the degree of union membership among staff pharmacists in 6 states, (2) compare the practice settings, work activities and conditions, compensation, and demographic characteristics between union and nonunion staff pharmacists, (3) assess the level of interest in joining a union among nonunion staff pharmacists, and (4) compare the practice settings, work activities and working conditions, wages and benefits, and demographic characteristics between nonunion staff pharmacists interested in joining a union and nonunion staff pharmacists who were not interested in joining a union. A biennial pharmacist compensation study was conducted in 6 states (Florida, Iowa, Illinois, Minnesota, Tennessee, Wisconsin) in late 2003. Randomly selected pharmacists were mailed a self-administered questionnaire asking about their practice setting, work activities and conditions, wages and benefits, and demographic characteristics. Respondents were also asked to indicate current membership in a union and, if not a member, their desire to unionize their workplace. Compensation and unionization data were provided by 2,180 respondents (27% usable response rate), of which 1,226 (56%) were staff pharmacists. Eight percent of the staff pharmacists were union members, whereas 18% of nonunion members would vote to unionize their workplace. There were few statistically significant differences between union and nonunion staff pharmacists regarding work activities, working conditions, and hourly wages. However, the benefits provided to union staff pharmacists differed from those provided to nonunion staff pharmacists in several ways. Union staff pharmacists were younger than their nonunion counterparts (40.9 vs 44.5 years, P=.01), yet had worked for their current employers a longer time (11.1 vs 7.3 years, P=.03). Nonunion staff pharmacists interested in joining a union differed from those who would not by practice location and setting, working conditions, and benefits. Although the union membership rate among staff pharmacists is relatively low, there are geographic and practice areas where membership rates are higher. Differences in work activities, working conditions, wages, and benefits were noted between union and nonunion staff pharmacists as well as between those who would join a union and those who would not. These differences merit further investigation, especially with respect to evaluating the effectiveness of unions and identifying factors that may lead nonunionized staff pharmacists to join a union.
Chrysler Upset Protrusion Joining Techniques for Joining Dissimilar Metals
DOE Office of Scientific and Technical Information (OSTI.GOV)
Logan, Stephen
The project goal was to develop and demonstrate a robust, cost effective, and versatile joining technique, known as Upset Protrusion Joining (UPJ), for joining challenging dissimilar metal com-binations, especially those where one of the metals is a die cast magnesium (Mg) component. Since two of the key obstacles preventing more widespread use of light metals (especially in high volume automotive applications) are 1) a lack of robust joining techniques and 2) susceptibility to galvanic corrosion, and since the majority of the joint combinations evaluated in this project include die cast Mg (the lightest structural metal) as one of the twomore » materials being joined, and since die casting is the most common and cost effective process for producing Mg components, then successful project completion provides a key enabler to high volume application of lightweight materials, thus potentially leading to reduced costs, and encouraging implementation of lightweight multi-material vehicles for significant reductions in energy consumption and reduced greenhouse gas emissions. Eco-nomic benefits to end-use consumers are achieved primarily via the reduction in fuel consumption. Unlike currently available commercial processes, the UPJ process relies on a very robust mechanical joint rather than intermetallic bonding, so the more cathodic material can be coated prior to joining, thus creating a robust isolation against galvanic attack on the more anodic material. Additionally, since the UPJ protrusion is going through a hole that can be pre-drilled or pre-punched prior to coating, the UPJ process is less likely to damage the coating when the joint is being made. Further-more, since there is no additional cathodic material (such as a steel fastener) used to create the joint, there is no joining induced galvanic activity beyond that of the two parent materials. In accordance with its originally proposed plan, this project has successfully developed process variants of UPJ to enable joining of Mg die castings to aluminum (Al) and steel sheet components of various thicknesses, strengths and coating configurations. While most development focused on the simpler round boss version of the process, an additional phase of the work focused on devel-opment of an oval boss version to support applications with narrow flanges, while yet another vari-ant of the process, known as Upset Cast Riveting (UCR), was developed and evaluated for joining mixed metals that may not necessarily include Mg or Al die cast components. Although each varia-tion posed unique challenges described later in the report, all variations were successfully produced and evaluated, and each could be further developed for specific types of commercial applications. In this project, UPJ performed favorably against the benchmark self-pierce riveting (SPR) process in Mg AM60B to Al 6013 combinations although significant corrosion challenges were observed in both processes, especially for the bare Mg to bare Al configurations. Additional challenges were observed in joining Mg to steel with the UPJ process (SPR was not evaluated for this combination as it was not considered viable). To pass FCA’s specified corrosion tests with Mg/steel combina-tions, new steel treatments were evaluated, as well as adhesives and sealed edges. These showed significant improvement. In general, UPJ performed very well in Mg to Al 6016 combinations, even in corrosion evaluation of the bare Mg to bare Al configuration (again, SPR was not evaluated for this material combination as the 1.1 mm thick Al6016 sheet thickness was considered too thin for the SPR process). The improvement in corrosion performance of the Mg to Al 6016 combina-tion over the Mg to Al 6013 combination was thought to be a result of the lower copper content in the Al 6016 alloy. Oval boss joints showed substantial improvement in all joint strength criteria compared to 8.0-mm diameter round boss joints but were not evaluated for corrosion performance. The improved joint strength is likely a result of larger shear area. Cosmetic corrosion performance of all test assemblies (UPJ, UCR and SPR) was a challenge due to exposed edges and crevices al-lowing undercutting of the coatings. In real world component applications, the exposed edges, so prevalent on the joining test coupons, would be less prevalent and easier to protect.« less
How to Find the Right Therapist
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75 FR 43144 - Certain Steel Grating from the People's Republic of China: Countervailing Duty Order
Federal Register 2010, 2011, 2012, 2013, 2014
2010-07-23
... been slit and expanded, and does not involve welding or joining of multiple pieces of steel. The scope... formed, and does not involve welding or joining of multiple pieces of steel. Certain steel grating that...
METHOD FOR JOINING ALUMINUM TO STAINLESS STEEL
Lemon, L.C.
1960-05-24
Aluminum may be joined to stainless steel without the use of flux by tinning the aluminum with a tin solder containing 1% silver and 1% lead, tinning the stainless steel with a 50% lead 50% tin solder, and then sweating the tinned surfaces together.
91. VIEW OF THE SOUTHWEST CORNER WHERE THE TOWER JOINS ...
91. VIEW OF THE SOUTHWEST CORNER WHERE THE TOWER JOINS THE WEST GABLE & THE BRICK STEPS LEAD UP TO A SMALL VERANDAH (DUPLICATE OF HABS No. AL-765-34) - Kenworthy Hall, State Highway 14 (Greensboro Road), Marion, Perry County, AL
NASA Astrophysics Data System (ADS)
Amro, Elias; Kouadri-Henni, Afia
2018-05-01
Restrictions in pollutant emissions dictated at the European Commission level in the past few years have urged mass production car manufacturers to engage rapidly several strategies in order to reduce significantly the energy consumption of their vehicles. One of the most relevant taken action is light-weighting of body in white (BIW) structures, concretely visible with the increased introduction of polymer-based composite materials reinforced by carbon/glass fibers. However, the design and manufacturing of such "hybrid" structures is limiting the use of conventional assembly techniques like resistance spot welding (RSW) which are not transferable as they are for polymer-metal joining. This research aims at developing a joining technique that would eventually enable the assembly of a sheet molding compound (SMC) polyester thermoset-made component on a structure composed of several high strength steel grades. The state of the art of polymer-metal joining techniques highlighted the few ones potentially able to respond to the industrial challenge, which are: structural bonding, self-piercing riveting (SPR), direct laser joining and friction spot welding (FSpW). In this study, the promising SPR technique is investigated. Modelling of SPR process in the case of polymer-metal joining was performed through the building of a 2D axisymmetric FE model using the commercial code Abaqus CAE 6.10-1. Details of the numerical approach are presented with a particular attention to the composite sheet for which Mori-Tanaka's homogenization method is used in order to estimate overall mechanical properties. Large deformations induced by the riveting process are enabled with the use of a mixed finite element formulation ALE (arbitrary Lagrangian-Eulerian). FE model predictions are compared with experimental data followed by a discussion.
NASA Technical Reports Server (NTRS)
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.
Carey, Gemma; Crammond, Brad; Keast, Robyn
2014-10-20
The evidence base for the impact of social determinants of health has been strengthened considerably in the last decade. Increasingly, the public health field is using this as a foundation for arguments and actions to change government policies. The Health in All Policies (HiAP) approach, alongside recommendations from the 2010 Marmot Review into health inequalities in the UK (which we refer to as the 'Fairness Agenda'), go beyond advocating for the redesign of individual policies, to shaping the government structures and processes that facilitate the implementation of these policies. In doing so, public health is drawing on recent trends in public policy towards 'joined up government', where greater integration is sought between government departments, agencies and actors outside of government. In this paper we provide a meta-synthesis of the empirical public policy research into joined up government, drawing out characteristics associated with successful joined up initiatives.We use this thematic synthesis as a basis for comparing and contrasting emerging public health interventions concerned with joined-up action across government. We find that HiAP and the Fairness Agenda exhibit some of the characteristics associated with successful joined up initiatives, however they also utilise 'change instruments' that have been found to be ineffective. Moreover, we find that - like many joined up initiatives - there is room for improvement in the alignment between the goals of the interventions and their design. Drawing on public policy studies, we recommend a number of strategies to increase the efficacy of current interventions. More broadly, we argue that up-stream interventions need to be 'fit-for-purpose', and cannot be easily replicated from one context to the next.
Using Negotiated Joining to Construct and Fill Open-ended Roles in Elite Culinary Groups
Tan, Vaughn
2015-01-01
This qualitative study examines membership processes in groups operating in an uncertain environment that prevents them from fully predefining new members’ roles. I describe how nine elite high-end, cutting-edge culinary groups in the U.S. and Europe, ranging from innovative restaurants to culinary R&D groups, use negotiated joining—a previously undocumented process—to systematically construct and fill these emergent, open-ended roles. I show that negotiated joining is a consistently patterned, iterative process that begins with a role that both aspirant and target group explicitly understand to be provisional. This provisional role is then jointly modified and constructed by the aspirant and target group through repeated iterations of proposition, validation through trial and evaluation, and selective integration of validated role components. The initially provisional role stabilizes and the aspirant achieves membership if enough role components are validated; otherwise the negotiated joining process is abandoned. Negotiated joining allows the aspirant and target group to learn if a mutually desirable role is likely and, if so, to construct such a role. In addition, the provisional roles in negotiated joining can support absorptive capacity by allowing novel role components to enter target groups through aspirants’ efforts to construct stable roles for themselves, while the internal adjustment involved in integrating newly validated role components can have the unintended side effect of supporting adaptation by providing opportunities for the groups to use these novel role components to modify their role structure and goals to suit a changing and uncertain environment. Negotiated joining thus reveals role ambiguity’s hitherto unexamined beneficial consequences and provides a foundation for a contingency theory of new-member acquisition. PMID:26273105
Federal Register 2010, 2011, 2012, 2013, 2014
2010-01-06
... that has been slit and expanded, and does not involve welding or joining of multiple pieces of steel... pierced and cold formed, and does not involve welding or joining of multiple pieces of steel. Certain...
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Self-healing of cracks in Ag joining layer for die-attachment in power devices
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chen, Chuantong, E-mail: chenchuantong@sanken.osaka-u.ac.jp; Nagao, Shijo; Suganuma, Katsuaki
Sintered silver (Ag) joining has attracted significant interest in power devices modules for its ability to form stable joints with a porous interconnection layer. A function for the self-healing of cracks in sintered porous Ag interlayers at high temperatures is discovered and reported here. A crack which was prepared on a Ag joining layer was closed after heating at 200 °C in air. The tensile strength of pre-cracked Ag joining layer specimens recovers to the value of non-cracked specimens after heating treatment. Transmission electron microscopy (TEM) was used to probe the self-healing mechanism. TEM images and electron diffraction patterns show thatmore » a large quantity of Ag nanoparticles formed at the gap with the size less than 10 nm, which bridges the crack in the self-healing process. This discovery provides additional motivation for the application of Ag as an interconnection material for power devices at high temperature.« less
Mechanism of Microhomology-Mediated End-Joining Promoted by Human DNA Polymerase Theta
Kent, Tatiana; Chandramouly, Gurushankar; McDevitt, Shane Michael; Ozdemir, Ahmet Y.; Pomerantz, Richard T.
2014-01-01
Microhomology-mediated end-joining (MMEJ) is an error-prone alternative double-strand break repair pathway that utilizes sequence microhomology to recombine broken DNA. Although MMEJ is implicated in cancer development, the mechanism of this pathway is unknown. We demonstrate that purified human DNA polymerase θ (Polθ) performs MMEJ of DNA containing 3’ single-strand DNA overhangs with two or more base-pairs of homology, including DNA modeled after telomeres, and show that MMEJ is dependent on Polθ in human cells. Our data support a mechanism whereby Polθ facilitates end-joining and microhomology annealing then utilizes the opposing overhang as a template in trans which stabilizes the DNA synapse. Polθ exhibits a preference for DNA containing a 5’-terminal phosphate, similar to polymerases involved in non-homologous end-joining. Lastly, we identify a conserved loop domain that is essential for MMEJ and higher-order structures of Polθ which likely promote DNA synapse formation. PMID:25643323
DOE Office of Scientific and Technical Information (OSTI.GOV)
Henager, Charles H.; Nguyen, Ba Nghiep; Kurtz, Richard J.
2015-03-01
The use of SiC and SiC-composites in fission or fusion environments requires joining methods for assembling systems. The international fusion community designed miniature torsion specimens for joint testing and irradiation in test reactors with limited irradiation volumes. These torsion specimens fail out-of-plane when joints are strong and when elastic moduli are within a certain range compared to SiC, which causes difficulties in determining shear strengths for joints or for comparing unirradiated and irradiated joints. A finite element damage model was developed that indicates fracture is likely to occur within the joined pieces to cause out-of-plane failures for miniature torsion specimensmore » when a certain modulus and strength ratio between the joint material and the joined material exists. The model was extended to treat elastic-plastic joints such as SiC/epoxy and steel/epoxy joints tested as validation of the specimen design.« less
Delamination initiated by a defect
NASA Astrophysics Data System (ADS)
Biel, A.; Toftegaard, H.
2016-07-01
Composite materials in wind turbines are mainly joined with adhesives. Adhesive joining is preferable since it distributes the stresses over a larger area. This study shows how a defect can influence the fracture behaviour of adhesively joined composite. Repeated experiments are performed using double cantilever beam specimens loaded with bending moments. The specimens consist of two 8 mm thick GFRP-laminates which are joined by a 3 mm thick epoxy adhesive. A thin foil close to one of the laminates is used to start the crack. For some of the specimens a defect is created by an initial load-unload operation. During this operation, a clamp is used in order to prevent crack propagation in the main direction. For the specimens without defect, the crack propagates in the middle of the adhesive layer. For the specimens with defect, the crack directly deviates into the laminate. After about 25 mm propagation in the laminate, the crack returns to the adhesive. Compared to the adhesive the fracture energy for the laminate is significantly higher.
NASA Astrophysics Data System (ADS)
Picot, Florent; Gueydan, Antoine; Hug, Éric
2017-10-01
Lap joining configuration for Friction Stir Welding process is a methodology mostly dedicated to heterogeneous bonding. This welding technology was applied to join pure titanium with pure aluminum by varying the rotation speed and the movement speed of the tool. Regardless of the process parameters, it was found that the maximum strength of the junction remains almost constant. Microstructural observations by means of Scanning Electron Microscopy and Energy Dispersive Spectrometry analysis enable to describe the interfacial join and reveal asymmetric Cold Lap Defects on the sides of the junction. Chemical analysis shows the presence of one exclusive intermetallic compound through the interface identified as TiAl3. This compound is responsible of the crack spreading of the junction during the mechanical loading. The original version of this article supplied to AIP Publishing contained an accidental inversion of the authors, names. An updated version of this article, with the authors names formatted correctly was published on 20 October 2017.
NASA Astrophysics Data System (ADS)
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.
Reyes, Angelica N; Brown, Cary A
2018-01-01
Voluntary occupational therapy organizations fill an important role. However, recruitment and retention can be problematic. Little is known about factors influencing occupational therapists to join/maintain membership in professional associations. This study investigated factors influencing occupational therapists' decision to join/remain members of their association. An electronic survey was carried out and data were analyzed using SPSS software and manual categorization of open-ended comments. Two hundred and fifty-four therapists responded. Generation of new ideas, opportunities for professional development, self-improvement, maintenance of standards, improvement of the profession, and discounts on equipment/educational opportunities were significant factors in deciding to join the organization. The factors perceived as priorities varied in relation to participants' year of graduation. More-customized strategies, reflecting priorities that vary during a therapist's career path, may need to be employed to best address recruitment and retention across the range of therapists' needs and goals.
NASA Technical Reports Server (NTRS)
Thomas, F. P.
2006-01-01
Aerospace structures utilize innovative, lightweight composite materials for exploration activities. These structural components, due to various reasons including size limitations, manufacturing facilities, contractual obligations, or particular design requirements, will have to be joined. The common methodologies for joining composite components are the adhesively bonded and mechanically fastened joints and, in certain instances, both methods are simultaneously incorporated into the design. Guidelines and recommendations exist for engineers to develop design criteria and analyze and test composites. However, there are no guidelines or recommendations based on analysis or test data to specify a torque or torque range to apply to metallic mechanical fasteners used to join composite components. Utilizing the torque tension machine at NASA s Marshall Space Flight Center, an initial series of tests were conducted to determine the maximum torque that could be applied to a composite specimen. Acoustic emissions were used to nondestructively assess the specimens during the tests and thermographic imaging after the tests.
State-of-technology for joining TD-NiCr sheet.
NASA Technical Reports Server (NTRS)
Holko, K. H.; Moore, T. J.; Gyorgak, C. A.
1972-01-01
At the current state-of-technology there are many joining processes that can be used to make sound welds in TD-NiCr sheet. Some of these that are described in this report are electron beam welding (EBW), gas-tungsten arc welding (GTAW), diffusion welding (DFW), resistance spot welding (RSW), resistance seam welding (RSEW), and brazing. Roll welding (RW) and explosion welding (EXW) have not been developed to the point where they can be used to make sound welds in TD-NiCr. Joining work that has previously been done on TD-NiCr by various organizations, both privately supported and under Air Force and NASA contracts, is described in this summary. Current work is also described that is being done at General Dynamics/Convair (under NASA contract) and at NASA/Lewis to develop and evaluate DFW, RSW, RSEW, and brazing. Preliminary comparisons of joining processes are made for typical applications. A brief description of the manufacture of TD-NiCr sheet by a recently standardized process (under NASA contract) also is given.
Weldment for austenitic stainless steel and method
Bagnall, Christopher; McBride, Marvin A.
1985-01-01
For making defect-free welds for joining two austenitic stainless steel mers, using gas tungsten-arc welding, a thin foil-like iron member is placed between the two steel members to be joined, prior to making the weld, with the foil-like iron member having a higher melting point than the stainless steel members. When the weld is formed, there results a weld nugget comprising melted and then solidified portions of the joined members with small portions of the foil-like iron member projecting into the solidified weld nugget. The portions of the weld nugget proximate the small portions of the foil-like iron member which project into the weld nugget are relatively rich in iron. This causes these iron-rich nugget portions to display substantial delta ferrite during solidification of the weld nugget which eliminates weld defects which could otherwise occur. This is especially useful for joining austenitic steel members which, when just below the solidus temperature, include at most only a very minor proportion of delta ferrite.
Materials technology for Stirling space power converters
NASA Technical Reports Server (NTRS)
Baggenstoss, William; Mittendorf, Donald
1992-01-01
This program was conducted in support of the NASA LeRC development of the Stirling power converter (SPC) for space power applications. The objectives of this contract were: (1) to perform a technology review and analyses to support the evaluation of materials issues for the SPC; (2) to evaluate liquid metal compatibility issues of the SPC; (3) to evaluate and define a transient liquid phase diffusion bonding (TLPDB) process for the SPC joints to the Udimet 720 heater head; and (4) to evaluate alternative (to the TLPDB) joining techniques. In the technology review, several aspects of the current Stirling design were examined including the power converter assembly process, materials joining, gas bearings, and heat exchangers. The supporting analyses included GLIMPS power converter simulation in support of the materials studies, and system level analysis in support of the technology review. The liquid metal compatibility study evaluated process parameters for use in the Stirling power converter. The alternative joining techniques study looked at the applicability of various joining techniques to the Stirling power converter requirements.
NASA Technical Reports Server (NTRS)
Gyorgak, C. A.
1975-01-01
An evaluation was made of five braze filler metals for joining an aluminum-containing oxide dispersion-strengthened (ODS) alloy, TD-NiCrAl. All five braze filler metals evaluated are considered suitable for joining TD-NiCrAl in terms of wettability and flow. Also, the braze alloys appear to be tolerant of slight variations in brazing procedures since joints prepared by three sources using three of the braze filler metals exhibited similar brazing characteristics and essentially equivalent 1100 C stress-rupture properties in a brazed butt-joint configuration. Recommendations are provided for brazing the aluminum-containing ODS alloys.
Explosive Tube-to-fitting Joining of Small-diameter Tubes
NASA Technical Reports Server (NTRS)
Bement, L. J.
1985-01-01
An effort is currently under way by NASA Marshall Space Flight Center to upgrade the space shuttle main engine through the use of improved materials and processes. Under consideration is the use of the Langley Research Center explosive seam welding process. The objective is to demonstrate the feasibility of joining space shuttle main engine tube to fitting components in an oxygen heat exchanger, using the NASA LaRC explosive seam welding process. It was concluded that LaRC explosive joining is viable for this application; that there is no incompatability of materials; that ultrasonic inspection is the best nondestructive testing method; and that the .500 DIA joint experiences interface problems.
Loading Considerations for Implementing Friction STIR Welding for Large Diameter Tank Fabrication
NASA Technical Reports Server (NTRS)
Adams, Glynn
1998-01-01
The main objectives of the research presented here are to determine the reaction loads associated with friction stir welding (FSW) and to determine the suitability of an existing welding fixture for implementing this welding process in the fabrication of large diameter tanks. Friction stir welding is a relatively new process which is being investigated as a method for joining aluminum alloys. The aluminum-lithium alloy, Al-Li 2195, which is being used to fabricate the super-light-weight shuttle external tank has proven difficult to join using fusion techniques. Therefore, FSW and its potential applicability to joining Al-Li 2195 are of particular interest to NASA.
Tool and process for miniature explosive joining of tubes
NASA Technical Reports Server (NTRS)
Bement, Laurence J. (Inventor); Bailey, James W. (Inventor)
1987-01-01
A tool and process to be used in the explosive joining of tubes is disclosed. The tool consists of an initiator, a tool form, and a ribbon explosive. The assembled tool is a compact, storable, and safe device suitable for explosive joining of small, lightweight tubes down to 0.20 inch in diameter. The invention is inserted into either another tube or a tube plate. A shim or standoff between the two surfaces to be welded is necessary. Initiation of the explosive inside the tube results in a high velocity, angular collision between the mating surfaces. This collision creates surface melts and collision bonding wherein electron-sharing linkups are formed.
Toroid Joining Gun For Fittings And Couplings
NASA Technical Reports Server (NTRS)
Fox, Robert L.; Swaim, Robert J.; Johnson, Samuel D.; Buckley, John D.; Copeland, Carl E.; Coultrip, Robert H.; Johnston, David F.; Phillips, William M.
1992-01-01
Hand-held gun used to join metal heat-to-shrink couplings. Uses magnetic induction (eddy currents) to produce heat in metal coupling, and thermocouple to measure temperature and signals end of process. Gun, called "toroid joining gun" concentrates high levels of heat in localized areas. Reconfigured for use on metal heat-to-shrink fitting and coupling applications. Provides rapid heating, operates on low power, lightweight and portable. Safe for use around aircraft fuel and has no detrimental effects on surrounding surfaces or objects. Reliable in any environment and under all weather conditions. Gun logical device for taking full advantage of capabilities of new metal heat-to-shrink couplings and fittings.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hoelzer, David T.; Bunn, Jeffrey R.; Gussev, Maxim N.
The development of friction stir welding (FSW) for joining thin sections of the advanced oxide dispersion strengthened (ODS) 14YWT ferritic alloy was initiated in Fuel Cycle Research and Development (FCRD), now the Nuclear Technology Research and Development (NTRD), in 2015. The first FSW experiment was conducted in late FY15 and successfully produced a bead-on-plate stir zone (SZ) on a 1 mm thick plate of 14YWT (SM13 heat). The goal of this research task is to ultimately demonstrate that FSW is a feasible method for joining thin wall (0.5 mm thick) tubing of 14YWT.
Distributed coupling high efficiency linear accelerator
Tantawi, Sami G.; Neilson, Jeffrey
2016-07-19
A microwave circuit for a linear accelerator includes multiple monolithic metallic cell plates stacked upon each other so that the beam axis passes vertically through a central acceleration cavity of each plate. Each plate has a directional coupler with coupling arms. A first coupling slot couples the directional coupler to an adjacent directional coupler of an adjacent cell plate, and a second coupling slot couples the directional coupler to the central acceleration cavity. Each directional coupler also has an iris protrusion spaced from corners joining the arms, a convex rounded corner at a first corner joining the arms, and a corner protrusion at a second corner joining the arms.
75 FR 61481 - Supplemental Notice of Meeting
Federal Register 2010, 2011, 2012, 2013, 2014
2010-10-05
... Consulting to study the effects of Entergy Services, Inc. and Cleco Power joining the Southwest Power Pool... Entergy Services, Inc. and Cleco Power Joining the Southwest Power Pool Regional Transmission Organization... 27, 2010. On September 15, 2010, the Commission provided notice that a meeting will be held to...
Explosive Joining for Nuclear-Reactor Repair
NASA Technical Reports Server (NTRS)
Bement, L. J.; Bailey, J. W.
1983-01-01
In explosive joining technique, adapter flange from fuel channel machined to incorporate a V-notch interface. Ribbon explosive, 1/2 inch (1.3 cm) in width, drives V-notched wall of adapter into bellows assembly, producing atomic-level metallurgical bond. Ribbon charge yields joint with double parent metal strength.
Choe, Myoung-Ae; Kuwano, Noriko; Bang, Kyung-Sook; Cho, Mi-Kyoung; Yatsushiro, Rika; Kawata, Yuki
The purpose of this study was to identify differences in motivation for joining disaster relief activities as a nurse in the future between Japanese and Korean nursing students. A descriptive 2-group comparative study design was used. The participants were 721 first- to fourth-year nursing students (Japanese, n = 324; Korean, n = 397). From June to September 2014, data were collected through a researcher-administered questionnaire and self-reported answers. The collected data were analyzed by descriptive statistics, the χ test, and the t test.No significant difference was found between Japanese and Korean students in motivation to join domestic relief activities should a disaster occur in the area in which they lived. Compared with Korean students, Japanese students strongly agreed that it is necessary to carry out relief work across borders when disasters occur in foreign countries (p = .001). Meanwhile, Japanese students showed less motivation than Korean students to join relief activities in other domestic areas and foreign countries (p = .020).The results of this study suggest that the motivation of Japanese students to join disaster relief activities as nurses in the future should a disaster occur in other domestic areas and foreign countries needs to be increased. The results also suggest that undergraduate students should be well prepared for disasters through disaster nursing education, including practical training, disaster drills, and simulation.
Potapov, Vladimir; Ong, Jennifer L; Langhorst, Bradley W; Bilotti, Katharina; Cahoon, Dan; Canton, Barry; Knight, Thomas F; Evans, Thomas C; Lohman, Gregory Js
2018-05-08
DNA ligases are key enzymes in molecular and synthetic biology that catalyze the joining of breaks in duplex DNA and the end-joining of DNA fragments. Ligation fidelity (discrimination against the ligation of substrates containing mismatched base pairs) and bias (preferential ligation of particular sequences over others) have been well-studied in the context of nick ligation. However, almost no data exist for fidelity and bias in end-joining ligation contexts. In this study, we applied Pacific Biosciences Single-Molecule Real-Time sequencing technology to directly sequence the products of a highly multiplexed ligation reaction. This method has been used to profile the ligation of all three-base 5'-overhangs by T4 DNA ligase under typical ligation conditions in a single experiment. We report the relative frequency of all ligation products with or without mismatches, the position-dependent frequency of each mismatch, and the surprising observation that 5'-TNA overhangs ligate extremely inefficiently compared to all other Watson-Crick pairings. The method can easily be extended to profile other ligases, end-types (e.g. blunt ends and overhangs of different lengths), and the effect of adjacent sequence on the ligation results. Further, the method has the potential to provide new insights into the thermodynamics of annealing and the kinetics of end-joining reactions.
All-round joining method with carbon fiber reinforced interface
NASA Astrophysics Data System (ADS)
Miwa, Noriyoshi; Tanaka, Kazunori; Kamiya, Yoshiko; Nishi, Yoshitake
2008-08-01
Carbon fiber reinforced polymer (CFRP) has been recently applied to not only wing, but also fan blades of turbo fan engines. To prevent impact force, leading edge of titanium was often mounted on the CFRP fan blades with adhesive force. In order to enhance the joining strength, a joining method with carbon fiber reinforced interface has been developed. By using nickel-coated carbon fibers, a joining sample with carbon fiber-reinforced interface between CFRP and CFRM has been successfully developed. The joining sample with nickel-coated carbon fiber interface exhibits the high tensile strength, which was about 10 times higher than that with conventional adhesion. On the other hand, Al-welding methods to steel, Cu and Ti with carbon fiber reinforced interface have been successfully developed to lighten the parts of machines of racing car and airplane. Carbon fibers in felt are covered with metals to protect the interfacial reaction. The first step of the welding method is that the Al coated felt is contacted and wrapped with molten aluminum solidified under gravity pressure, whereas the second step is that the felt with double layer of Ni and Al is contacted and wrapped with molten steel (Cu or Ti) solidified under gravity pressure. Tensile strength of Al-Fe (Cu or Ti) welded sample with carbon fiber reinforced interface is higher than those of Al-Fe (Cu or Ti) welded sample.
Emphasizing Social Features in Information Portals: Effects on New Member Engagement
Sharma, Nikhil; Butler, Brian S.; Irwin, Jeannie; Spallek, Heiko
2013-01-01
Many information portals are adding social features with hopes of enhancing the overall user experience. Invitations to join and welcome pages that highlight these social features are expected to encourage use and participation. While this approach is widespread and seems plausible, the effect of providing and highlighting social features remains to be tested. We studied the effects of emphasizing social features on users' response to invitations, their decisions to join, their willingness to provide profile information, and their engagement with the portal's social features. The results of a quasi-experiment found no significant effect of social emphasis in invitations on receivers' responsiveness. However, users receiving invitations highlighting social benefits were less likely to join the portal and provide profile information. Social emphasis in the initial welcome page for the site also was found to have a significant effect on whether individuals joined the portal, how much profile information they provided and shared, and how much they engaged with social features on the site. Unexpectedly, users who were welcomed in a social manner were less likely to join and provided less profile information; they also were less likely to engage with social features of the portal. This suggests that even in online contexts where social activity is an increasingly common feature, highlighting the presence of social features may not always be the optimal presentation strategy. PMID:23626487
Experimental Investigation on the Joining of Aluminum Alloy Sheets Using Improved Clinching Process.
Chen, Chao; Zhao, Shengdun; Han, Xiaolan; Zhao, Xuzhe; Ishida, Tohru
2017-08-01
Aluminum alloy sheets have been widely used to build the thin-walled structures by mechanical clinching technology in recent years. However, there is an exterior protrusion located on the lower sheet and a pit on the upper sheet, which may restrict the application of the clinching technology in visible areas. In the present study, an improved clinched joint used to join aluminum alloy sheets was investigated by experimental method. The improved clinching process used for joining aluminum alloy evolves through four phases: (a) localized deformation; (b) drawing; (c) backward extrusion; and (d) mechanical interlock forming. A flat surface can be produced using the improved clinching process. Shearing strength, tensile strength, material flow, main geometrical parameters, and failure mode of the improved clinched joint were investigated. The sheet material was compressed to flow radially and upward using a punch, which generated a mechanical interlock by producing severe localized plastic deformation. The neck thickness and interlock of the improved clinched joint were increased by increasing the forming force, which also contributed to increase the strength of the clinched joint. The improved clinched joint can get high shearing strength and tensile strength. Three main failure modes were observed in the failure process, which were neck fracture mode, button separation mode, and mixed failure mode. The improved clinched joint has better joining quality to join aluminum alloy sheets on the thin-walled structures.
NASA Astrophysics Data System (ADS)
Cook, Grant O.; Sorensen, Carl D.
2013-12-01
Partial transient liquid-phase (PTLP) bonding is currently an esoteric joining process with limited applications. However, it has preferable advantages compared with typical joining techniques and is the best joining technique for certain applications. Specifically, it can bond hard-to-join materials as well as dissimilar material types, and bonding is performed at comparatively low temperatures. Part of the difficulty in applying PTLP bonding is finding suitable interlayer combinations (ICs). A novel interlayer selection procedure has been developed to facilitate the identification of ICs that will create successful PTLP bonds and is explained in a companion article. An integral part of the selection procedure is a filtering routine that identifies all possible ICs for a given application. This routine utilizes a set of customizable parameters that are based on key characteristics of PTLP bonding. These parameters include important design considerations such as bonding temperature, target remelting temperature, bond solid type, and interlayer thicknesses. The output from this routine provides a detailed view of each candidate IC along with a broad view of the entire candidate set, greatly facilitating the selection of ideal ICs. This routine provides a new perspective on the PTLP bonding process. In addition, the use of this routine, by way of the accompanying selection procedure, will expand PTLP bonding as a viable joining process.
Experimental Investigation on the Joining of Aluminum Alloy Sheets Using Improved Clinching Process
Chen, Chao; Zhao, Shengdun; Han, Xiaolan; Zhao, Xuzhe; Ishida, Tohru
2017-01-01
Aluminum alloy sheets have been widely used to build the thin-walled structures by mechanical clinching technology in recent years. However, there is an exterior protrusion located on the lower sheet and a pit on the upper sheet, which may restrict the application of the clinching technology in visible areas. In the present study, an improved clinched joint used to join aluminum alloy sheets was investigated by experimental method. The improved clinching process used for joining aluminum alloy evolves through four phases: (a) localized deformation; (b) drawing; (c) backward extrusion; and (d) mechanical interlock forming. A flat surface can be produced using the improved clinching process. Shearing strength, tensile strength, material flow, main geometrical parameters, and failure mode of the improved clinched joint were investigated. The sheet material was compressed to flow radially and upward using a punch, which generated a mechanical interlock by producing severe localized plastic deformation. The neck thickness and interlock of the improved clinched joint were increased by increasing the forming force, which also contributed to increase the strength of the clinched joint. The improved clinched joint can get high shearing strength and tensile strength. Three main failure modes were observed in the failure process, which were neck fracture mode, button separation mode, and mixed failure mode. The improved clinched joint has better joining quality to join aluminum alloy sheets on the thin-walled structures. PMID:28763027
NASA Technical Reports Server (NTRS)
Kiser, J. Douglas; Singh, Mrityunjay; Lei, Jin-Fen; Martin, Lisa C.
1999-01-01
A novel attachment approach for positioning sensor lead wires on silicon carbide-based monolithic ceramic and fiber reinforced ceramic matrix composite (FRCMC) components has been developed. This approach is based on an affordable, robust ceramic joining technology, named ARCJoinT, which was developed for the joining of silicon carbide-based ceramic and fiber reinforced composites. The ARCJoinT technique has previously been shown to produce joints with tailorable thickness and good high temperature strength. In this study, silicon carbide-based ceramic and FRCMC attachments of different shapes and sizes were joined onto silicon carbide fiber reinforced silicon carbide matrix (SiC/ SiC) composites having flat and curved surfaces. Based on results obtained in previous joining studies. the joined attachments should maintain their mechanical strength and integrity at temperatures up to 1350 C in air. Therefore they can be used to position and secure sensor lead wires on SiC/SiC components that are being tested in programs that are focused on developing FRCMCs for a number of demanding high temperature applications in aerospace and ground-based systems. This approach, which is suitable for installing attachments on large and complex shaped monolithic ceramic and composite components, should enhance the durability of minimally intrusive high temperature sensor systems. The technology could also be used to reinstall attachments on ceramic components that were damaged in service.
Processing and characterization of phase boundaries in ceramic and metallic materials
NASA Astrophysics Data System (ADS)
Zeng, Liang
The goal of this dissertation work was to explore and describe advanced characterization of novel materials processing. These characterizations were carried out using scanning and transmission electron microscopy (SEM and TEM), and X-ray diffraction techniques. The materials studied included ceramics and metallic materials. The first part of this dissertation focuses on the processing, and the resulting interfacial microstructure of ceramics joined using spin-on interlayers. SEM, TEM, and indentation tests were used to investigate the interfacial microstructural and mechanical property evolution of polycrystalline zirconia bonded to glass ceramic MaCor(TM), and polycrystalline alumina to single crystal alumina. Interlayer assisted specimens were joined using a thin amorphous silica interlayer. This interlayer was produced by spin coating an organic based silica bond material precursor and curing at 200°C, followed by joining in a microwave cavity or conventional electric furnace. Experimental results indicate that in the joining of the zirconia and MaCor(TM) no significant interfacial microstructural and mechanical property differences developed between materials joined either with or without interlayers, due to the glassy nature of MaCor(TM). The bond interface was non-planar, as a result of the strong wetting of MaCor(TM) and silica and dissolution of the zirconia. However, without the aid of a silica interlayer, sapphire and 98% polycrystalline alumina failed to join under the experimental conditions under this study. A variety of interfacial morphologies have been observed, including amorphous regions, fine crystalline alumina, and intimate contact between the sapphire and polycrystalline alumina. In addition, the evolution of the joining process from the initial sputter-cure to the final joining state and joining mechanisms were characterized. The second part of this dissertation focused on the effects of working and heat treatment on microstructure, texture, phase boundary movement, and mechanical property evolution in Ti-6Al-4V wire. The as-received wire consisted of equilibrium a and metastable beta phases and had a moderately strong fiber texture with prism plane normals aligned with the wire axis. The wire was worked by extrusion, solution heat-treatment and water quenching, and aging. The extrusion process strengthened the as-received texture. After solutionization and quenching, microstrucual observations showed the presence of many needlelike martensitic platelets in the prior beta phase regions. Texture analysis revealed that a secondary fiber with basal plane normals aligned with the wire axis emerged at the expense of the initial texture, indicating that highly preferred phase boundary motion (variant selection) occurred during the beta → alpha transformation. The strength of the variant selection consistently increased with solutionization temperature and time. In addition, the effects of dislocation type and density on variant selections were further investigated. This implies that strategic prior deformation and heat treatment can be exploited to design the resulting texture and microstructure and consequently optimize the properties of titanium products.
Joining the Video-Game Literacy Club: A Reluctant Mother Tries to Join the "Flow"
ERIC Educational Resources Information Center
Norton-Meier, Lori
2005-01-01
The author discusses the influence of video games and other technologies on modern family life, drawing on her own experiences. The implications of digital and other "new" and multiple literacies are described, with reference particularly to the work of Patrick Shannon and James Paul Gee.
Why Universities Join Cross-Sector Social Partnerships: Theory and Evidence
ERIC Educational Resources Information Center
Siegel, David J.
2010-01-01
Cross-sector partnerships are an increasingly popular mode of organizing to address intractable social problems, yet theory and research have virtually ignored university involvement in such activity. This article attempts to ascertain the reasons universities join networks of other social actors to support a common cause. Theories on the…
Deformation and Forming of Joined Materials
DOE Office of Scientific and Technical Information (OSTI.GOV)
Carsley, John; Hovanski, Yuri; Clarke, Kester D.
2014-09-23
Introductory article to a set of invited papers from the TMS committee on shaping and forming. This paper introduces a set of papers that were prepared to discussing the deformation and forming of joined materials, and to announce an upcoming symposium at the 2015 MS&T meeting in Columbus Ohio.
SAN FRANCISCO – Computational drug design company Numerate has signed a letter of intent to join an open consortium of scientists staffed from two U.S. national laboratories, industry, and academia working to transform drug discovery and developmen
Dan Macumber Photo of Daniel Macumber Dan Macumber Engineering Daniel.Macumber@nrel.gov | 303-384 -6172 Orcid ID http://orcid.org/0000-0002-6909-4725 Daniel joined NREL in 2008 and works in the and interoperability. Prior to joining NREL, Daniel worked as a software developer working on
Underage Children and Social Networking
ERIC Educational Resources Information Center
Weeden, Shalynn; Cooke, Bethany; McVey, Michael
2013-01-01
Despite minimum age requirements for joining popular social networking services such as Facebook, many students misrepresent their real ages and join as active participants in the networks. This descriptive study examines the use of social networking services (SNSs) by children under the age of 13. The researchers surveyed a sample of 199…
Orbital friction stir weld system
NASA Technical Reports Server (NTRS)
Ding, R. Jeffrey (Inventor); Carter, Robert W. (Inventor)
2001-01-01
This invention is an apparatus for joining the ends of two cylindrical (i.e., pipe-shaped) sections together with a friction stir weld. The apparatus holds the two cylindrical sections together and provides back-side weld support as it makes a friction stir weld around the circumference of the joined ends.
Joining Forces: The Case of Alliant International University
ERIC Educational Resources Information Center
Leslie, Heather
2013-01-01
Mergers and acquisitions are a prevalent force in higher education as more colleges and universities are joining forces to expand resources, enhance missions, or prevent closures. This study examines the merger of Alliant University (formerly California School of Professional Psychology) with United States International University to create what…
BMC Obesity - expanding the BMC series into an important area of research.
Horne, Genevieve; McTernan, Philip; Visscher, Tommy; Peeters, Anna
2014-01-01
This Editorial marks the launch of an important new journal to join the BMC series portfolio - BMC Obesity. BMC Obesity joins BMC Cancer as the second journal within the series to focus on a particular condition in the human body and the factors that contribute towards it.
Joining Forces: A Response to Kathy Rentz from the European Perspective
ERIC Educational Resources Information Center
Louhiala-Salminen, Leena
2010-01-01
In this article, the author responds to Kathy Rentz. She happily joins forces for pedagogically defensible teaching conditions and gives a brief "activist" account from the European perspective. However, rather than "European," she emphasizes that for the most part, this response looks at business communication teachers'…
NASA Technical Reports Server (NTRS)
Bateman, W. A.
1984-01-01
Cylindrical tubes joined together, end to end, by method employing adhesive, tapered ends, and spacing wires. Tapered joint between tubular structural elements provides pressure between bonding surfaces during adhesive curing. Spacing wires prevent adhesive from being scraped away when one element inserted in other. Method developed for assembling structural elements made of composite materials.
Personal Influence on the Decision to Join Voluntary Associations.
ERIC Educational Resources Information Center
Booth, Alan James
A longitudinal study (1961-1965) was planned to obtain information on the pervasiveness of personal influence with respect to decisions to join formal voluntary associations; examine the characteristics of opinion leaders and the individuals they influence; discover the differential patterns of joiners' exposure to mass communicated messages about…
Joining the Circle: Circle Banking on the Rosebud Reservation.
ERIC Educational Resources Information Center
Haase, Eric
1992-01-01
Describes the Sicangu Enterprise Center which provides training in business management and small loans to help Rosebud Sioux tribal members join with peers to start small businesses within their communities. Explains the center's innovative revolving loan fund. Highlights the businesses of an automechanic, a seamstress, and a sculptor. (DMM)
The design of a joined wing flight demonstrator aircraft
NASA Technical Reports Server (NTRS)
Smith, S. C.; Cliff, S. E.; Kroo, I. M.
1987-01-01
A joined-wing flight demonstrator aircraft has been developed at the NASA Ames Research Center in collaboration with ACA Industries. The aircraft is designed to utilize the fuselage, engines, and undercarriage of the existing NASA AD-1 flight demonstrator aircraft. The design objectives, methods, constraints, and the resulting aircraft design, called the JW-1, are presented. A wind-tunnel model of the JW-1 was tested in the NASA Ames 12-foot wind tunnel. The test results indicate that the JW-1 has satisfactory flying qualities for a flight demonstrator aircraft. Good agreement of test results with design predictions confirmed the validity of the design methods used for application to joined-wing configurations.
Research and Development Opportunities for Joining Technologies in HVAC&R
DOE Office of Scientific and Technical Information (OSTI.GOV)
Goetzler, William; Guernsey, Matt; Young, Jim
The Building Technologies Office (BTO) works with researchers and industry partners to develop and deploy technologies that can substantially reduce energy consumption and greenhouse gas (GHG) emissions in residential and commercial buildings. This opportunity assessment aims to advance BTO’s energy savings, GHG reduction, and other program goals by identifying research and development (R&D) initiatives for joining technologies in heating, ventilation, air-conditioning, and refrigeration (HVAC&R) systems. Improving joining technologies for HVAC&R equipment has the potential to increase lifetime equipment operating efficiency, decrease equipment and project cost, and most importantly reduce hydroflourocarbon (HFC) refrigerant leakage to support HFC phasedown and GHG reductionmore » goals.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Reza-E-Rabby, Md.; Ross, Kenneth; Overman, Nicole R.
A new solid-phase technique called friction stir dovetailing (FSD) has been developed for joining thick section aluminum to steel. In FSD, mechanical interlocks are formed at the aluminum-steel interface and are reinforced by metallurgical bonds where intermetallic growth has been uniquely suppressed. Lap shear testing shows superior strength and extension at failure compared to popular friction stir approaches where metallurgical bonding is the only joining mechanism. High resolution microscopy revealed the presence of a 40-70 nm interlayer having a composition of 76.4 at% Al, 18.4 at% Fe, and 5.2 at% Si, suggestive of limited FeAl3 intermetallic formation.
Letter from Thomas Moran to Ferdinand Hayden and Paintings by Thomas Moran
ERIC Educational Resources Information Center
Potter, Lee Ann; Eder, Elizabeth K.; Hussey, Michael
2012-01-01
Medical doctor and geologist Dr. Ferdinand Vandiveer Hayden selected more than 30 scientists, technical personnel, and artists, including photographer William Henry Jackson and painter Thomas Moran, to join the survey of the Yellowstone region in northwest Wyoming territory. Thomas Moran was an accomplished artist when he joined the survey to…
ETR, TRA642. WALL SECTION DETAILS. METAL SIDING JOINS TO ELECTRICAL ...
ETR, TRA-642. WALL SECTION DETAILS. METAL SIDING JOINS TO ELECTRICAL BUILDING, OFFICE BUILDING, AND ROOF. KAISER ETR-5528-MTR-A-13, 11/1955. INL INDEX NO. 532-0642-00-486-100920, REV. 4. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID
Community Leaders Speak Out against Substance Abuse. 1993 Report to the Nation.
ERIC Educational Resources Information Center
Join Together, Boston, MA.
The Join Together National Advisory Committee was created to help communities be more effective in developing and implementing strategies to reduce the harm from substance abuse. Join Together conducted this national report to describe community coalitions and to assess their contributions and needs. The findings are intended to help coalitions,…
ERIC Educational Resources Information Center
Olson, Cathy Applefeld
2011-01-01
A growing number of students in Blue Springs, Missouri, are joining the band, drawn by a band director who emphasizes caring and inclusiveness. In the four years since Melissia Goff arrived at Blue Springs High School, the school's extensive band program has swelled. The marching band alone has gone from 100 to 185 participants. Also under Goff's…
46 CFR 56.75-30 - Pipe joining details.
Code of Federal Regulations, 2010 CFR
2010-10-01
... be either of the socket or butt type. When butt joints are employed the edges to be joined shall be.... Circumferential joints may be either of the butt or socket type. Where butt joints are employed, the included... annular clearance of socket joints shall be held to small clearances which experience indicates is...
46 CFR 56.75-30 - Pipe joining details.
Code of Federal Regulations, 2014 CFR
2014-10-01
... be either of the socket or butt type. When butt joints are employed the edges to be joined shall be.... Circumferential joints may be either of the butt or socket type. Where butt joints are employed, the included... annular clearance of socket joints shall be held to small clearances which experience indicates is...
46 CFR 56.75-30 - Pipe joining details.
Code of Federal Regulations, 2013 CFR
2013-10-01
... be either of the socket or butt type. When butt joints are employed the edges to be joined shall be.... Circumferential joints may be either of the butt or socket type. Where butt joints are employed, the included... annular clearance of socket joints shall be held to small clearances which experience indicates is...
46 CFR 56.75-30 - Pipe joining details.
Code of Federal Regulations, 2012 CFR
2012-10-01
... be either of the socket or butt type. When butt joints are employed the edges to be joined shall be.... Circumferential joints may be either of the butt or socket type. Where butt joints are employed, the included... annular clearance of socket joints shall be held to small clearances which experience indicates is...
46 CFR 56.75-30 - Pipe joining details.
Code of Federal Regulations, 2011 CFR
2011-10-01
... be either of the socket or butt type. When butt joints are employed the edges to be joined shall be.... Circumferential joints may be either of the butt or socket type. Where butt joints are employed, the included... annular clearance of socket joints shall be held to small clearances which experience indicates is...
California Institute for Water Resources - California Institute for Water
Information Nitrogen Management Rosenberg Forum Follow us on Twitter Join Email List 174446display Resources Publications Keep in Touch QUICK LINKS Our Blog: The Confluence Drought & Water Information Nitrogen Management Rosenberg Forum Follow us on Twitter Join Email List 174446display Share Print Site Map
George Scott George Scott Researcher IV-Software Engineering George.Scott@nrel.gov | 303-384-6903 Orcid ID http://orcid.org/0000-0002-7983-3050 George joined NREL (then SERI) in 1985. He specializes in turbines and wind plants. Before joining NREL, George was a research geophysicist with Superior Oil in
Joining precipitation-hardened nickel-base alloys by friction welding
NASA Technical Reports Server (NTRS)
Moore, T. J.
1972-01-01
Solid state deformation welding process, friction welding, has been developed for joining precipitation hardened nickel-base alloys and other gamma prime-strengthened materials which heretofore have been virtually unweldable. Method requires rotation of one of the parts to be welded, but where applicable, it is an ideal process for high volume production jobs.
Federal Register 2010, 2011, 2012, 2013, 2014
2011-11-15
...; Toshiba Corporation, Yokohama, Japan; Panasonic Semiconductor Discrete Devices Co., Ltd., Kyoto, Japan... and admit program members that only join certain discrete projects and thus only have access to information and intellectual property created under the discrete projects that these lower-tiered members join...
Gang Prevention: An Overview of Research and Programs. Juvenile Justice Bulletin
ERIC Educational Resources Information Center
Howell, James C.
2010-01-01
This bulletin presents research on why youth join gangs and how a community can build gang prevention and intervention services. The author summarizes recent literature on gang formation and identifies promising and effective programs for gang prevention. The following are some key findings: (1) Youth join gangs for protection, enjoyment, respect,…
Joining the On-Line Community. An Introduction for Adult Literacy. Practice Guide.
ERIC Educational Resources Information Center
Rethemeyer, R. Karl
This technology guide is intended to introduce adult literacy providers to the concepts,hardware, and procedures of online communication. The six-part guide explains the following: (1) what electronic networks are; (2) why adult literacy practitioners may want to join the Internet; (3) how adult literacy practitioners are already using the…
Examining Decision Making Level of Wrestlers in Terms of Some Variable
ERIC Educational Resources Information Center
Yigit, Sihmehmet; Dalbudak, Ibrahim; Musa, Mihriay; Gürkan, Alper C.; Dalkiliç, Mehmet
2016-01-01
The aim of this research is to examine decision making level of wrestlers who joined Turkey inter university wrestling championship, according to variables as wrestlers' sex, age, grade, department, and education type. Study group consists of 34 females and 196 males, totally 230 athletes, who joined Turkey Inter University Wrestling Championship…
-275-3784 Zhiwen joined the Thermal Systems Group in 2009 to work in the field of Concentrating Solar thermal management and packaging, and gas turbines. He taught in the Department of Engineering Mechanics book chapter, and was awarded two patents in the areas of fuel cells and thermal fluids. Before joining
ERIC Educational Resources Information Center
Curriculum Review, 2008
2008-01-01
Celebrated annually on April 22, schools and communities organize numerous activities during Earth Day to promote awareness. To help teachers plan their own initiatives and to learn more about what is happening around the world, they can join the Earth Day Network at: http://network.earthday.net/. Once they have joined, they can create a webpage…
Philosophy for Children Kenyan Style
ERIC Educational Resources Information Center
Odierna, Rebecca
2012-01-01
It was the last day of Philosophy 492, the author's college course dedicated to teaching the principles and strategies of philosophy for children (p4c) Hawai'i. Months before she joined the Philosophy 492 class, she was asked to join Emerging Humanity as a volunteer in a project that focused on enhancing the classroom environments at the…
The multi-mode modulator: A versatile fluidic device for two-dimensional gas chromatography.
Seeley, John V; Schimmel, Nicolaas E; Seeley, Stacy K
2018-02-09
A fluidic device called the multi-mode modulator (MMM) has been developed for use as a comprehensive two-dimensional gas chromatography (GC x GC) modulator. The MMM can be employed in a wide range of capacities including as a traditional heart-cutting device, a low duty cycle GC x GC modulator, and a full transfer GC x GC modulator. The MMM is capable of producing narrow component pulses (widths <50ms) while operating at flows compatible with high resolution chromatography. The sample path of modulated components is confined to the interior of a joining capillary. The joining capillary dimensions and the position of the columns within the joining capillary can be optimized for the selected modulation mode. Furthermore, the joining capillary can be replaced easily and inexpensively if it becomes fouled due to sample matrix components or column bleed. The principles of operation of the MMM are described and its efficacy is demonstrated as a heart-cutting device and as a GC x GC modulator. Copyright © 2017 Elsevier B.V. All rights reserved.
Numerical investigation of electromagnetic pulse welded interfaces between dissimilar metals
DOE Office of Scientific and Technical Information (OSTI.GOV)
Xu, Wei; Sun, Xin
Electromagnetic pulse welding (EMPW), an innovative high-speed joining technique, is a potential method for the automotive industry in joining and assembly of dissimilar lightweight metals with drastically different melting temperatures and other thermal physical properties, such as thermal conductivity and thermal expansion coefficients. The weld quality of EMPW is significantly affected by a variety of interacting physical phenomena including large plastic deformation, materials mixing, localized heating and rapid cooling, possible localized melting and subsequent diffusion and solidification, micro-cracking and void, etc. In the present study, a thermo-mechanically coupled dynamic model has been developed to quantitatively resolve the high-speed impact joiningmore » interface characteristics as well as the process-induced interface temperature evolution, defect formation and possible microstructural composition variation. Reasonably good agreement has been obtained between the predicted results and experimental measurements in terms of interfacial morphology characteristics. The modeling framework is expected to provide further understanding of the hierarchical interfacial features of the non-equilibrium material joining process and weld formation mechanisms involved in the EMPW operation, thus accelerating future development and deployment of this advanced joining technology.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Henager, Charles H.; Nguyen, Ba Nghiep; Kurtz, Richard J.
2014-06-30
The use of SiC and SiC-composites in fission or fusion environments appears to require joining methods for assembling systems. The international fusion community has designed miniature torsion specimens for joint testing and for irradiation in HFIR. Therefore, miniature torsion joints were fabricated using displacement reactions between Si and TiC to produce Ti3SiC2 + SiC joints with CVD-SiC that were tested in shear prior to and after HFIR irradiation. However, these torsion specimens fail out-of-plane, which causes difficulties in determining a shear strength for the joints or for comparing unirradiated and irradiated joints. A finite element damage model has been developedmore » that indicates fracture is likely to occur within the joined pieces to 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 implications for torsion shear joint data based on this sample design are discussed.« less
Alternative end-joining pathway(s): bricolage at DNA breaks.
Frit, Philippe; Barboule, Nadia; Yuan, Ying; Gomez, Dennis; Calsou, Patrick
2014-05-01
To cope with DNA double strand break (DSB) genotoxicity, cells have evolved two main repair pathways: homologous recombination which uses homologous DNA sequences as repair templates, and non-homologous Ku-dependent end-joining involving direct sealing of DSB ends by DNA ligase IV (Lig4). During the last two decades a third player most commonly named alternative end-joining (A-EJ) has emerged, which is defined as any Ku- or Lig4-independent end-joining process. A-EJ increasingly appears as a highly error-prone bricolage on DSBs and despite expanding exploration, it still escapes full characterization. In the present review, we discuss the mechanism and regulation of A-EJ as well as its biological relevance under physiological and pathological situations, with a particular emphasis on chromosomal instability and cancer. Whether or not it is a genuine DSB repair pathway, A-EJ is emerging as an important cellular process and understanding A-EJ will certainly be a major challenge for the coming years. Copyright © 2014 The Authors. Published by Elsevier B.V. All rights reserved.
High-energy electron beams for ceramic joining
NASA Astrophysics Data System (ADS)
Turman, Bob N.; Glass, S. J.; Halbleib, J. A.; Helmich, D. R.; Loehman, Ron E.; Clifford, Jerome R.
1995-03-01
Joining of structural ceramics is possible using high melting point metals such as Mo and Pt that are heated with a high energy electron beam, with the potential for high temperature joining. A 10 MeV electron beam can penetrate through 1 cm of ceramic, offering the possibility of buried interface joining. Because of transient heating and the lower heat capacity of the metal relative to the ceramic, a pulsed high power beam has the potential for melting the metal without decomposing or melting the ceramic. We have demonstrated the feasibility of the process with a series of 10 MeV, 1 kW electron beam experiments. Shear strengths up to 28 MPa have been measured. This strength is comparable to that reported in the literature for bonding silicon nitride (Si3N4) to molybdenum with copper-silver-titanium braze, but weaker than that reported for Si3N4 - Si3N4 with gold-nickel braze. The bonding mechanism appears to be formation of a thin silicide layer. Beam damage to the Si3N4 was also assessed.
Launching biosimilar rituximab: an industry opinion on biosimilar uptake in Europe.
Trollope, Richard; Johnson, Sue; Ireland, Henry
2017-06-01
Richard Trollope and Sue Johnson talk with Henry Ireland, Senior Editor about the recent approval of biosimilar rituximab (Truxima ® ) & the current state of biosimilar uptake across Europe Richard Trollope, Head of Biosimilars, Mundipharma International Limited, qualified as a biochemist before joining Wyeth's commercial operations, prior to its acquisition by Pfizer. Richard later joined Yamanouchi Pharmaceuticals (now Astellas Pharma). His fascination with oncology led him to join Mundipharma in Europe and after joining the company's UK arm (Napp Pharmaceuticals Limited), Richard began his journey in biosimilars. He now heads up the biosimilar franchise at Mundipharma International as it launches biosimilar rituximab (Truxima ® ) - the first biosimilar monoclonal antibody for the treatment of cancer, which will be distributed by Napp Pharmaceuticals in the UK. Sue Johnson, PhD, Medical Insights at Mundipharma International Limited, is a scientist by background and completed her postdoc fellowship at Harvard Medical School. On returning to the UK, she began her career in the pharmaceutical industry, working in UK Medical Affairs before transitioning to a European role with Mundipharma 2 years ago, where she leads on Medical Insights for the biosimilars franchise.
Microassembly of Heterogeneous Materials using Transfer Printing and Thermal Processing
Keum, Hohyun; Yang, Zining; Han, Kewen; Handler, Drew E.; Nguyen, Thong Nhu; Schutt-Aine, Jose; Bahl, Gaurav; Kim, Seok
2016-01-01
Enabling unique architectures and functionalities of microsystems for numerous applications in electronics, photonics and other areas often requires microassembly of separately prepared heterogeneous materials instead of monolithic microfabrication. However, microassembly of dissimilar materials while ensuring high structural integrity has been challenging in the context of deterministic transferring and joining of materials at the microscale where surface adhesion is far more dominant than body weight. Here we present an approach to assembling microsystems with microscale building blocks of four disparate classes of device-grade materials including semiconductors, metals, dielectrics, and polymers. This approach uniquely utilizes reversible adhesion-based transfer printing for material transferring and thermal processing for material joining at the microscale. The interfacial joining characteristics between materials assembled by this approach are systematically investigated upon different joining mechanisms using blister tests. The device level capabilities of this approach are further demonstrated through assembling and testing of a microtoroid resonator and a radio frequency (RF) microelectromechanical systems (MEMS) switch that involve optical and electrical functionalities with mechanical motion. This work opens up a unique route towards 3D heterogeneous material integration to fabricate microsystems. PMID:27427243
In vitro non-homologous DNA end joining assays—The 20th anniversary
Pastwa, Elzbieta; Somiari, Richard I.; Malinowski, Mariusz; Somiari, Stella B.; Winters, Thomas A.
2010-01-01
DNA double-strand breaks (DSBs) are the most serious forms of DNA damage in cells. Unrepaired or misrepaired DSBs account for some of the genetic instabilities that lead to mutations or cell death, and consequently, to cancer predisposition. In human cells non-homologous DNA end joining (NHEJ) is the main repair mechanism of these breaks. Systems for DNA end joining study have been developing during the last 20 years. New assays have some advantages over earlier in vitro DSBs repair assays because they are less time-consuming, allow the use of clinical material and examination of the joining DNA ends produced physiologically in mammalian cells. Proteins involved in NHEJ repair pathway can serve as biomarkers or molecular targets for anticancer drugs. Results of studies on NHEJ in cancer could help to select potent repair inhibitors that may selectively sensitize tumor cells to ionizing radiation (IR) and chemotherapy. Here, we review the principles and practice of in vitro NHEJ assays and provide some insights into the future prospects of this assay in cancer diagnosis and treatment. PMID:19110069
Simonetti, Angelita; Marzi, Stefano; Billas, Isabelle M. L.; Tsai, Albert; Fabbretti, Attilio; Myasnikov, Alexander G.; Roblin, Pierre; Vaiana, Andrea C.; Hazemann, Isabelle; Eiler, Daniel; Steitz, Thomas A.; Puglisi, Joseph D.; Gualerzi, Claudio O.; Klaholz, Bruno P.
2013-01-01
Translation initiation factor 2 (IF2) promotes 30S initiation complex (IC) formation and 50S subunit joining, which produces the 70S IC. The architecture of full-length IF2, determined by small angle X-ray diffraction and cryo electron microscopy, reveals a more extended conformation of IF2 in solution and on the ribosome than in the crystal. The N-terminal domain is only partially visible in the 30S IC, but in the 70S IC, it stabilizes interactions between IF2 and the L7/L12 stalk of the 50S, and on its deletion, proper N-formyl-methionyl(fMet)-tRNAfMet positioning and efficient transpeptidation are affected. Accordingly, fast kinetics and single-molecule fluorescence data indicate that the N terminus promotes 70S IC formation by stabilizing the productive sampling of the 50S subunit during 30S IC joining. Together, our data highlight the dynamics of IF2-dependent ribosomal subunit joining and the role played by the N terminus of IF2 in this process. PMID:24029017
Truong, Lan N.; Li, Yongjiang; Shi, Linda Z.; Hwang, Patty Yi-Hwa; He, Jing; Wang, Hailong; Razavian, Niema; Berns, Michael W.; Wu, Xiaohua
2013-01-01
Microhomology-mediated end joining (MMEJ) is a major pathway for Ku-independent alternative nonhomologous end joining, which contributes to chromosomal translocations and telomere fusions, but the underlying mechanism of MMEJ in mammalian cells is not well understood. In this study, we demonstrated that, distinct from Ku-dependent classical nonhomologous end joining, MMEJ—even with very limited end resection—requires cyclin-dependent kinase activities and increases significantly when cells enter S phase. We also showed that MMEJ shares the initial end resection step with homologous recombination (HR) by requiring meiotic recombination 11 homolog A (Mre11) nuclease activity, which is needed for subsequent recruitment of Bloom syndrome protein (BLM) and exonuclease 1 (Exo1) to DNA double-strand breaks (DSBs) to promote extended end resection and HR. MMEJ does not require S139-phosphorylated histone H2AX (γ-H2AX), suggesting that initial end resection likely occurs at DSB ends. Using a MMEJ and HR competition repair substrate, we demonstrated that MMEJ with short end resection is used in mammalian cells at the level of 10–20% of HR when both HR and nonhomologous end joining are available. Furthermore, MMEJ is used to repair DSBs generated at collapsed replication forks. These studies suggest that MMEJ not only is a backup repair pathway in mammalian cells, but also has important physiological roles in repairing DSBs to maintain cell viability, especially under genomic stress. PMID:23610439
Primary Care Clinics and Accountable Care Organizations
Tang, Chiung-Ya; Lin, Yi-Ling; Masri, Maysoun D.
2015-01-01
Background: The Accountable Care Organization (ACO) is one of the new models of health care delivery in the United States. To date, little is known about the characteristics of health care organizations that have joined ACOs. We report on the findings of a survey of primary care clinics, the objective of which was to investigate the opinions of clinic management about participation in ACOs and the characteristics of clinic organizational structure that may contribute to joining ACOs or be willing to do so. Methods: A 27-item survey questionnaire was developed and distributed by mail in 3 annual waves to all Rural Health Clinics (RHCs) in 9 states. Two dependent variables—participation in ACOs and willingness to join ACOs—were created and analyzed using a generalized estimating equation approach. Results: A total of 257 RHCs responded to the survey. A small percentage (5.2%) of the respondent clinics reported that they were participating in ACOs. Rural Health Clinics in isolated areas were 78% less likely to be in ACOs (odds ratio = 0.22, P = .059). Nonprofit RHCs indicated a higher willingness to join an ACO than for-profit RHCs (B = 1.271, P = .054). There is a positive relationship between RHC size and willingness to join an ACO (B = 0.402, P = .010). Conclusion: At this early stage of ACO development, many RHC personnel are unfamiliar with the ACO model. Rural providers’ limited technological and human resources, and the lack of ACO development in rural areas, may delay or prevent their participation in ACOs. PMID:26900587
Jia, Qi; den Dulk-Ras, Amke; Shen, Hexi; Hooykaas, Paul J J; de Pater, Sylvia
2013-07-01
Besides the KU-dependent classical non-homologous end-joining (C-NHEJ) pathway, an alternative NHEJ pathway first identified in mammalian systems, which is often called the back-up NHEJ (B-NHEJ) pathway, was also found in plants. In mammalian systems PARP was found to be one of the essential components in B-NHEJ. Here we investigated whether PARP1 and PARP2 were also involved in B-NHEJ in Arabidopsis. To this end Arabidopsis parp1, parp2 and parp1parp2 (p1p2) mutants were isolated and functionally characterized. The p1p2 double mutant was crossed with the C-NHEJ ku80 mutant resulting in the parp1parp2ku80 (p1p2k80) triple mutant. As expected, because of their role in single strand break repair (SSBR) and base excision repair (BER), the p1p2 and p1p2k80 mutants were shown to be sensitive to treatment with the DNA damaging agent MMS. End-joining assays in cell-free leaf protein extracts of the different mutants using linear DNA substrates with different ends reflecting a variety of double strand breaks were performed. The results showed that compatible 5'-overhangs were accurately joined in all mutants, that KU80 protected the ends preventing the formation of large deletions and that PARP proteins were involved in microhomology mediated end joining (MMEJ), one of the characteristics of B-NHEJ.
Join or be excluded from biomedicine? JOINS and Post-colonial Korea.
Ma, Eunjeong
2015-04-01
This paper discusses re-emergence of Korean medicine(s) in the global context with a focus on a natural drug JOINS, a highly contentious drug regarding its legal status. By following through its life world, the paper contends that the drug is the embodiment of the postcolonial anxiety that crosses the intersections between the aspiring nation and globalizing strategies of the bio-pharmaceutical industry. JOINS is a natural drug prescribed to alleviate the symptoms of degenerative arthritis. SK Chemicals, Ltd., a giant domestic pharmaceutical company developed the drug by utilizing the knowledge of traditional pharmacopeia and put it on the market in 2001. In the domestic market, the drug is treated as a prescription drug, implying that Western medicine-trained doctors (as opposed to Korean medicine doctors) are entitled to prescribe drugs. It also indicates that the drug has undergone a series of lab tests such as toxicity, efficacy, and clinical trials in compliance with regulatory guidelines. However, the domestic standards are not rigorous enough to satisfy international standards, so that it is exported as a nutritional supplement abroad. The government, the pharmaceutical industry, and the Western medicine profession are happy with how the drug stands domestically and internationally. Rather, it is Korean doctors who try to disrupt the status quo and reclaim their rights to traditional knowledge, who have been alienated from the pharmaceuticalization of traditional knowledge. Thus, the JOINS tablet embodies the complex web of modern Korean society, professional interests, the pharmaceutical industry, and globalization.
ERIC Educational Resources Information Center
Delgado-Guerrero, Marla; Cherniack, Mayra A.; Gloria, Alberta M.
2014-01-01
This study sought to understand the reasons undergraduate women of color join a cultural-specific sorority. Through the use of an online survey, 159 narratives of women of color undergraduates attending predominately White institutions (PWIs) in the Midwest was conducted. LeCompte's (2000) 5-step analysis yielded four culturally focused…
Rothgeb, Timothy Moore [Norfolk, VA; Reece, Charles Edwin [Yorktown, VA
2009-06-02
A metallic seal or gasket for use in the joining of cryogenic fluid conduits, the seal or gasket having a generally planar and serpentine periphery defining a central aperture. According to a preferred embodiment, the periphery has at least two opposing elongated serpentine sides and two opposing arcuate ends joining the opposing elongated serpentine sides and is of a hexagonal cross-section.
Astronaut Garneau working with Audio Control System panel
1996-06-05
STS077-392-007 (19-29 May 1996) --- Inside the Spacehab Module onboard the Earth-orbiting Space Shuttle Endeavour, Canadian astronaut Marc Garneau, mission specialist, joins astronaut Curtis L. Brown, Jr., pilot, in checking out the audio control system for Spacehab. The two joined four other NASA astronauts for nine days of research and experimentation in Earth-orbit.
The Video Comprehension Strategies of Chinese-Speaking University Students
ERIC Educational Resources Information Center
Lin, Lu-Fang
2011-01-01
This study reports the strategies used by second language learners to comprehend computerized video material. In total, 211 students taking an English course in a public university in Taiwan joined the study, conducted over 1 academic year during which 63 students were involved in the pilot study in the first semester, and 148 joined the formal…
Joining the Conversation: Twitter as a Tool for Student Political Engagement
ERIC Educational Resources Information Center
Journell, Wayne; Ayers, Cheryl A.; Beeson, Melissa Walker
2013-01-01
This article describes possibilities afforded by using social media, specifically Twitter, as a way to encourage students to join political conversations across the United States and around the world. In this study, we describe a project in which students used Twitter to share commentary about the state of the 2012 presidential election. The…
Federal Register 2010, 2011, 2012, 2013, 2014
2010-06-08
...: (202) 482-3936. SUPPLEMENTARY INFORMATION: Case History The period of investigation (``POI'') is... slit and expanded, and does not involve welding or joining of multiple pieces of steel. The scope of... cold formed, and does not involve welding or joining of multiple pieces of steel. Certain steel grating...
Differentials in Characteristics between Parent Group Members and Non-Members.
ERIC Educational Resources Information Center
Keenan, Vincent; Suelzle, Marijean
Three hundred twenty-nine parents of developmentally disabled children (0 to 21 years old) were surveyed to test the hypothesis that parents who join parent groups are more likely to be white, highly educated, currently married, Republican, and to have higher family incomes than those who do not join parent groups. The survey questionnaire was…
NASA Technical Reports Server (NTRS)
1996-01-01
In order to more easily join the huge sections of the Space Shuttle external tank, Marshall Space Flight Center initiated development of the existing concept of Variable Polarity Plasma Arc (VPPA) welding. VPPA welding employs a variable current waveform that allows the system to operate for preset time increments in either of two polarity modes for effective joining of light alloys.
Your chance to shape the future of the RCN and the profession.
2017-07-19
Offering you the chance to join a committee is unlikely to set your pulse racing, so let's put it another way: would you like to join a group of dynamic nurses who will help shape the future of the RCN and the wider nursing profession? If the answer is yes, then read on.
12 CFR Appendix G to Part 360 - Deposit-Customer Join File Structure
Code of Federal Regulations, 2014 CFR
2014-01-01
... 12 Banks and Banking 5 2014-01-01 2014-01-01 false Deposit-Customer Join File Structure G Appendix G to Part 360 Banks and Banking FEDERAL DEPOSIT INSURANCE CORPORATION REGULATIONS AND STATEMENTS OF GENERAL POLICY RESOLUTION AND RECEIVERSHIP RULES Pt. 360, App. G Appendix G to Part 360—Deposit-Customer...
12 CFR Appendix G to Part 360 - Deposit-Customer Join File Structure
Code of Federal Regulations, 2011 CFR
2011-01-01
... 12 Banks and Banking 4 2011-01-01 2011-01-01 false Deposit-Customer Join File Structure G Appendix G to Part 360 Banks and Banking FEDERAL DEPOSIT INSURANCE CORPORATION REGULATIONS AND STATEMENTS OF GENERAL POLICY RESOLUTION AND RECEIVERSHIP RULES Pt. 360, App. G Appendix G to Part 360—Deposit-Customer...
12 CFR Appendix G to Part 360 - Deposit-Customer Join File Structure
Code of Federal Regulations, 2012 CFR
2012-01-01
... 12 Banks and Banking 5 2012-01-01 2012-01-01 false Deposit-Customer Join File Structure G Appendix G to Part 360 Banks and Banking FEDERAL DEPOSIT INSURANCE CORPORATION REGULATIONS AND STATEMENTS OF GENERAL POLICY RESOLUTION AND RECEIVERSHIP RULES Pt. 360, App. G Appendix G to Part 360—Deposit-Customer...
12 CFR Appendix G to Part 360 - Deposit-Customer Join File Structure
Code of Federal Regulations, 2013 CFR
2013-01-01
... 12 Banks and Banking 5 2013-01-01 2013-01-01 false Deposit-Customer Join File Structure G Appendix G to Part 360 Banks and Banking FEDERAL DEPOSIT INSURANCE CORPORATION REGULATIONS AND STATEMENTS OF GENERAL POLICY RESOLUTION AND RECEIVERSHIP RULES Pt. 360, App. G Appendix G to Part 360—Deposit-Customer...
ERIC Educational Resources Information Center
Okech, David
2012-01-01
Objectives: Using baseline and second wave data, the study evaluated the measurement and structural properties of parenting stress, personal mastery, and economic strain with N = 381 lower income parents who decided to join and those who did not join in a child development savings account program. Methods: Structural equation modeling mean and…
Student Chapters: Meeting Expectations and Providing High Quality Experiences
ERIC Educational Resources Information Center
Davis, Casey E.; Juengling, Lisa B.; Laurent, Rebekah D.; Pye, Nicole; Williamson, James
2014-01-01
Why do students join student chapters? What do they hope to gain from joining them? The Louisiana State University (LSU) chapter of the Society of American Archivists (SAA) conducted a research project that addresses these questions. The SAA-LSU chapter surveyed LIS students and recent graduates from the 61 ALA accredited LIS programs in the…
1996-01-01
In order to more easily join the huge sections of the Space Shuttle external tank, Marshall Space Flight Center initiated development of the existing concept of Variable Polarity Plasma Arc (VPPA) welding. VPPA welding employs a variable current waveform that allows the system to operate for preset time increments in either of two polarity modes for effective joining of light alloys.
12 CFR Appendix G to Part 360 - Deposit-Customer Join File Structure
Code of Federal Regulations, 2010 CFR
2010-01-01
..._Code Relationship CodeThe code indicating how the customer is related to the account. Possible values... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Deposit-Customer Join File Structure G Appendix... GENERAL POLICY RESOLUTION AND RECEIVERSHIP RULES Pt. 360, App. G Appendix G to Part 360—Deposit-Customer...
5 CFR 1201.36 - Consolidating and joining appeals.
Code of Federal Regulations, 2011 CFR
2011-01-01
... subsequent dismissal if the same appellant filed both appeals. (b) Action by judge. A judge may consolidate or join cases on his or her own motion or on the motion of a party if doing so would: (1) Expedite... motion for consolidation or joinder must be filed within 10 days of the date of service of the motion. ...
5 CFR 1201.36 - Consolidating and joining appeals.
Code of Federal Regulations, 2010 CFR
2010-01-01
... subsequent dismissal if the same appellant filed both appeals. (b) Action by judge. A judge may consolidate or join cases on his or her own motion or on the motion of a party if doing so would: (1) Expedite... motion for consolidation or joinder must be filed within 10 days of the date of service of the motion. ...
Department of Defense October 2002 Youth Poll Overview Report
2003-04-01
motivated to join. Of those who felt that engaging in battle was likely in the next four years, 30% were more likely to join the military, essentially the...job? K. Do you expect to spend part of your career in a government job? PS4 . Now I am going to read you some activities people have suggested for
75 FR 81433 - Airworthiness Directives; Airbus Model A321-211, -212, -231, and -232 Airplanes
Federal Register 2010, 2011, 2012, 2013, 2014
2010-12-28
... join individual electrical wires in the Wing Tank harness installations to in-tank equipment on QT... are used to join individual electrical wires in the Wing Tank harness installations to in-tank... electrical wires in the Wing Tank harness installations to in-tank equipment on QT circuit. The failure of a...
ERIC Educational Resources Information Center
Join Together, Boston, MA.
This guide accompanies Join Together's recommendations for drug and alcohol abuse prevention for policymakers and communities. It presents strategic examples of how major institutions and residents in communities have paid attention to substance abuse and worked to overcome its effects. Part 1 contains the recommendations and key policies…
"LinkedIn" for Accounting and Business Students
ERIC Educational Resources Information Center
Albrecht, W. David
2011-01-01
LinkedIn is a social media application that every accounting and business student should join and use. LinkedIn is a database of 90,000,000 business professionals that enables each to connect and interact with their business associates. Five reasons are offered for why accounting students should join LinkedIn followed by 11 hints for use.
ERIC Educational Resources Information Center
Warmerdam, Amanda; Lewis, Ioni; Banks, Tamara
2015-01-01
Purpose: Using the Theory of Planned Behaviour (TPB) framework, the purpose of this paper is to explore whether the standard TPB constructs explained variance in Generation Y (Gen Y) individuals' intentions to join their ideal organisation. Design/methodology/approach: A mixed methods approach was used featuring qualitative and quantitative…
Evaluating the Effects of Child Savings Accounts Program Participation on Parental Well-Being
ERIC Educational Resources Information Center
Okech, David
2012-01-01
Objectives: Using baseline and second wave data, the study evaluated the impact of child savings accounts participation on parenting stress, personal mastery, and economic strain with N = 381 lower income parents who decided to join and those who did not join in a child development savings account program. Methods: Structural equation modeling for…
Activity during first EVA of STS-72 mission
1996-01-15
STS072-305-034 (15 Jan. 1996) --- Astronaut Daniel T. Barry, mission specialist, works in the cargo bay of the Space Shuttle Endeavour during the first of two extravehicular activities (EVA). Barry was joined by astronaut Leroy Chiao for the EVA. The two joined four other NASA astronauts for a week and a half aboard Endeavour.
NASA Technical Reports Server (NTRS)
Leete, II, John H. (Inventor); Skinner, William J. (Inventor)
1989-01-01
Structural members for a frame or truss are formed of two substantially identical elongated tubular like members each having a planar extending wall with the tubular members joined together along the planar wall, back to back, and end portions of the joined planar walls form extending lugs. A complementary joint fitting includes a clevis having a slot for receiving the lug.
1982-03-01
embryo European government is not taken seriously. Direct election of the European Parliament in 1979 was a gesture toward stronger institutional...Spanish past, Spaniards want to join in a common European destiny . They also want to consolidate the democratization that has been achieved by joining
Rapid induction bonding of composites, plastics, and metals
NASA Technical Reports Server (NTRS)
Buckley, John D.; Fox, Robert L.
1991-01-01
The Toroid Bonding Gun is and induction heating device. It is a self contained, portable, low powered induction welding system developed for bonding or joining plastic, ceramic, or metallic parts. Structures can be bonded in a factory or in a the field. This type of equipment allows for applying heat directly to the bond lines and/or to the adhesives without heating the entire structure, supports, and fixtures of a bonding assembly. The induction heating gun originally developed for use in the fabrication of space Gangs of bonders are now used to rapidly join composite sheet and structural components. Other NASA-developed applications of this bonding technique include the joining of thermoplastic composites, thermosetting composites, metals, and combinations of these materials.
Predator avoidance as a function of flocking in the sexually dichromatic Hawaii akepa
Hart, P.J.; Freed, L.A.
2005-01-01
Hypotheses for joining a mixed-species bird flock consider each species as a single unit. In sexually dichromatic birds, differential conspicuousness between the sexes may result in differences in vigilance for predators. Aspects of the predator avoidance and foraging enhancement hypotheses for the selective value of joining a mixed-species flock were assessed for the strongly sexually dichromatic Hawaii akepa (Loxops coccineus coccineus). There was support for the primary predictions of the predator avoidance hypothesis: vigilance levels decreased with increasing group size, and with membership in a flock, but only for brightly colored adult males. There was little support for the hypothesis that the primary benefit of joining a mixed-species flock is to enhance foraging efficiency through "local enhancement".
Characterisation of the joining zone of serially arranged hybrid semi-finished components
NASA Astrophysics Data System (ADS)
Behrens, B.-A.; Chugreev, A.; Matthias, T.
2018-05-01
Forming of already joined semi-finished products is an innovative approach to manufacture components which are well-adapted to external loads. This approach results in an economically and ecologically improved production by the targeted use of high-quality materials in component areas, which undergo high stresses. One possible production method for hybrid semi-finished products is friction welding. This welding method allows for the production of hybrid semi-finished products made of aluminium and steel as well as steel and steel. In this paper, the thermomechanical tensile and shear stresses causing a failure of the joined zone are experimentally determined through tension tests. These tests are performed with specimens whose joint zones are aligned with different angles to the load direction.
Advances in Solid State Joining of High Temperature Alloys
NASA Technical Reports Server (NTRS)
Ding, R. Jeff; Schneider, Judy; Walker, Bryant
2011-01-01
Many of the metals used in the oil and gas industry are difficult to fusion weld including titanium and its alloys. Thus solid state joining processes, such as friction stir welding (FSWing) and a patented modification termed thermal stir welding (TSWing), are being pursued as alternatives to produce robust structures more amenable to high pressure applications. Unlike the FSWing process where the tool is used to heat the workpiece, TSWing utilizes an induction coil to preheat the material prior to stirring thus minimizing the burden on the weld tool and thereby extending its life. This study reports on the initial results of using a hybrid (H)-TSW process to join commercially pure, 1.3cm thick panels of titanium (CP Ti) Grade 2.
Flexible ordering of antibody class switch and V(D)J joining during B-cell ontogeny
Kumar, Satyendra; Wuerffel, Robert; Achour, Ikbel; Lajoie, Bryan; Sen, Ranjan; Dekker, Job; Feeney, Ann J.; Kenter, Amy L.
2013-01-01
V(D)J joining is mediated by RAG recombinase during early B-lymphocyte development in the bone marrow (BM). Activation-induced deaminase initiates isotype switching in mature B cells of secondary lymphoid structures. Previous studies questioned the strict ontological partitioning of these processes. We show that pro-B cells undergo robust switching to a subset of immunoglobulin H (IgH) isotypes. Chromatin studies reveal that in pro-B cells, the spatial organization of the Igh locus may restrict switching to this subset of isotypes. We demonstrate that in the BM, V(D)J joining and switching are interchangeably inducible, providing an explanation for the hyper-IgE phenotype of Omenn syndrome. PMID:24240234
Synthesis of terpene and steroid dimers and trimers having cyclobutadienyl-Co and aromatic tethers.
Sierra, Miguel A; Torres, M Rosario; Torre, María C de la; Alvaro, Elsa
2007-05-25
The reaction of natural product derived propargylic alcohols with CpCo(CO)2 produces three new types of natural product hybrids having two or three terpene or steroid fragments. The tether joining the natural product subunits is built during the reaction. Type 1 hybrids have two terpene or steroid moieties joined by a CpCo-cyclobutadiene tether, with the two units disposed in a 1,2-arrangement (9, 14, 22). Type 2 hybrids have a Co-cyclopentadienone tether (10). Type 3 has three units of terpene or steroid joined to a benzene ring (11, 12, 15). An unusual Co-mediated beta-carbon elimination pathway of propargylic alcohols leading to ketones (an unknown process in this chemistry) has been observed.
Who joins the network? Physicians' resistance to take budgetary co-responsibility.
Rischatsch, Maurus
2015-03-01
Managed Care (MC) is expected to provide health care at a lower cost than conventional provision. Therefore, Switzerland intends to promote MC by forcing health insurers to write MC contracts and introducing budgetary co-responsibility for ambulatory care physicians. A discrete choice experiment conducted in 2011 including 872 physicians reveals a strong preference heterogeneity with respect to network participation and alternative remuneration schemes. The number of physicians working in networks is unlikely to rise on a voluntary basis, while general practitioners are more likely to join networks than specialists with surgical activities. For physicians considering joining networks, cost savings are predicted to be higher than the estimated willingness-to-accept payments. Copyright © 2014 Elsevier B.V. All rights reserved.
Fundamental studies on a novel die concept for round-point shear-clinching
NASA Astrophysics Data System (ADS)
Hörhold, Réjane; Müller, Martin; Merklein, Marion; Meschut, Gerson
2016-10-01
A newly-developed round-point shear-clinching technology could increase the use of different materials like well formable aluminium and hardly formable ultra-high-strength steels (UHSS). This innovative technology joins in a single-stage process without any pilot-hole, surface pre-treatment or auxiliary joining part. The combination of an inner and outer punch realises an indirect cutting operation of the die-sided material, whereas the punch-sided material remains unharmed. The current die-sided tool set acts as a cutting die and enables a radial extrusion of the punch-sided material after being drawn though the created hole in the UHSS. The die has a fixed die depth. After ejecting the joined components, the slug has to be removed from the top of the spring-loaded anvil. The novel die concept investigated in this paper offers the possibility to push the slug continuously through the die in the joining direction. The removed slugs remain inside the die, so manual removal is unnecessary. The one-parted tool is supposed to be more robust than the multi-parted one that is currently used. This paper represents the task to evaluate the geometry of a useful shear-clinching die concept. To reduce the experimental effort, FEM should assist the development of the most promising approach. To quantify the success, conventional shear-clinching with opening die acts as a reference. The results show the high potential and the raison d'être of shear-clinching technologies as a mechanical joining technology for future multimaterial applications especially for UHSS.
Singh, Ipsha; Nair, K Chandrasekharan; Shetty, Jayakar
2017-01-01
The aim of this study is to evaluate the strain developed in simulated mandibular model before and after the joining of an implant-supported screw-retained prosthesis by different joining techniques, namely, arc welding, laser welding, and soldering. A specimen simulating a mandibular edentulous ridge was fabricated in heat-cured acrylic resin. 4-mm holes were drilled in the following tooth positions; 36, 33, 43, 46. Implant analogs were placed in the holes. University of California, Los Angeles, abutment was attached to the implant fixture. Eight strain gauges were attached to the acrylic resin model. Six similar models were made. Implant-supported screw-retained fixed prosthesis was fabricated in nickel-chromium alloy. A load of 400 N was applied on the prosthesis using universal testing machine. Resultant strain was measured in each strain gauge. All the prostheses were sectioned at the area between 36 and 33, 33 and 43, and 43 and 46 using 35 micrometer carborundum disc, and strain was measured in each strain gauge after applying a load of 400 N on the prosthesis. Specimens were joined by arc welding, soldering, and laser welding. After joining, a load of 400 N was applied on each prosthesis and the resultant strain was measured in each strain gauge. Highest mean strain values were recorded before sectioning of the prostheses (889.9 microstrains). Lowest mean strain values were recorded after sectioning the prosthesis and before reuniting it (225.0 microstrains). Sectioning and reuniting the long-span implant prosthesis was found to be a significant factor in influencing the peri-implant strain.
Berenson, Robert A; Burton, Rachel A; McGrath, Megan
2016-09-01
Many view advanced primary care models such as the patient-centered medical home as foundational for accountable care organizations (ACOs), but it remains unclear how these two delivery reforms are complementary and how they may produce conflict. The objective of this study was to identify how joining an ACO could help or hinder a primary care practice's efforts to deliver high-quality care. This qualitative study involved interviews with a purposive sample of 32 early adopters of advanced primary care and/or ACO models, drawn from across the U.S. and conducted in mid-2014. Interview notes were coded using qualitative data analysis software, permitting topic-specific queries which were then summarized. Respondents perceived many potential benefits of joining an ACO, including care coordination staff, data analytics, and improved communication with other providers. However, respondents were also concerned about added "bureaucratic" requirements, referral restrictions, and a potential inability to recoup investments in practice improvements. Interviewees generally thought joining an ACO could complement a practice's efforts to deliver high-quality care, yet noted some concerns that could undermine these synergies. Both the advantages and disadvantages of joining an ACO seemed exacerbated for small practices, since they are most likely to benefit from additional resources yet are most likely to chafe under added bureaucratic requirements. Our identification of the potential pros and cons of joining an ACO may help providers identify areas to examine when weighing whether to enter into such an arrangement, and may help ACOs identify potential areas for improvement. Copyright © 2016 Elsevier Inc. All rights reserved.
Konomura, Naoto; Arai, Naoto; Shinohara, Takeshi; Kobayashi, Jun; Iwasaki, Wakana; Ikawa, Shukuko; Kusano, Kohji; Shibata, Takehiko
2017-01-01
RecA-family recombinase-catalyzed ATP-dependent homologous joint formation is critical for homologous recombination, in which RecA or Rad51 binds first to single-stranded (ss)DNA and then interacts with double-stranded (ds)DNA. However, when RecA or Rad51 interacts with dsDNA before binding to ssDNA, the homologous joint-forming activity of RecA or Rad51 is quickly suppressed. We found that under these and adenosine diphosphate (ADP)-generating suppressive conditions for the recombinase activity, RecA or Rad51 at similar optimal concentrations enhances the DNA ligase-catalyzed dsDNA end-joining (DNA ligation) about 30- to 40-fold. The DNA ligation enhancement by RecA or Rad51 transforms most of the substrate DNA into multimers within 2–5 min, and for this enhancement, ADP is the common and best cofactor. Adenosine triphosphate (ATP) is effective for RecA, but not for Rad51. Rad51/RecA-enhanced DNA ligation depends on dsDNA-binding, as shown by a mutant, and is independent of physical interactions with the DNA ligase. These observations demonstrate the common and unique activities of RecA and Rad51 to juxtapose dsDNA-ends in preparation for covalent joining by a DNA ligase. This new in vitro function of Rad51 provides a simple explanation for our genetic observation that Rad51 plays a role in the fidelity of the end-joining of a reporter plasmid DNA, by yeast canonical non-homologous end-joining (NHEJ) in vivo. PMID:27794044
Van Ryzin, Mark J; Dishion, Thomas J
2013-06-01
Aggression is one of the more stable characteristics of child and adolescent development, and violent behavior in early adulthood is often foreshadowed by aggressive behavior in childhood and early adolescence. Considerable evidence has linked coercive family interactions to aggressive behavior in childhood, but less research has been conducted on the joint role of family and peer interaction in the escalation of aggression to violence in adulthood. We coded family interactions at age 12-13 and friendship interaction at age 16-17 in a multiethnic sample of youth and families. Violence in young adulthood (age 22-23) was measured using self-report, criminal records, and parent report. We tested the hypothesis that a process of 'coercive joining' in friendship interactions mediated the relationship between coercive family interactions and serious violence. We found that observed coercive joining in friendships at age 16-17 predicted early-adulthood violent behavior over and above an established tendency toward antisocial behavior. We also found that observed coercive family interactions at age 12 predicted early-adulthood violence, and that coercive joining with friends fully mediated this link. These results significantly extend coercion theory by suggesting that coercive joining in the context of peer groups is an additional mechanism by which coercive processes in the family are extended and amplified to violent behavior in early adulthood. Our findings suggest the importance of addressing both individual interpersonal skills and self-organizing peer groups when intervening to prevent violent behavior. © 2012 The Authors. Journal of Child Psychology and Psychiatry © 2012 Association for Child and Adolescent Mental Health.
Development of a double beam process for joining aluminum and steel
NASA Astrophysics Data System (ADS)
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.
Increasing FSW join strength by optimizing feed rate, rotating speed and pin angle
NASA Astrophysics Data System (ADS)
Darmadi, Djarot B.; Purnowidodo, Anindito; Siswanto, Eko
2017-10-01
Principally the join in Friction Stir Welding (FSW) is formed due to mechanical bonding. At least there are two factors determines the quality of this join, first is the temperature in the area around the interface and secondly the intense of mixing forces in nugget zone to create the mechanical bonding. The adequate temperature creates good flowability of the nugget zone and an intensive mixing force produces homogeneous strong bonding. Based on those two factors in this research the effects of feed rate, rotating speed and pin angle of the FSW process to the tensile strength of resulted join are studied. The true experimental method was used. Feed rate was varied at 24, 42, 55 and 74 mm/minutes and from the experimental results, it can be concluded that the higher feed rate decreases the tensile strength of weld join and it is believed due to the lower heat embedded in the material. Inversely, the higher rotating speed increases the join’s tensile strength as a result of higher heat embedded in base metal and higher mixing force in the nugget zone. The rotating speed were 1842, 2257 and 2904 RPMs. The pin angle determines the direction of mixing force. With variation of pin angle: 0°, 4°, 8° and 12° the higher pin angle generally increases the tensile strength because of more intensive mixing force. For 12° pin angle the lower tensile strength is found since the force tends to push out the nugget area from the joint gap.
Yang, Jianjun; Wang, Ke; Liu, Guangyuan; Wang, Dashan
2013-11-01
Zirconia powder in nanometers can be fabricated into inter-joined abutment of dental implant system with the injection shaping technique. This study was to detect the resistance of inter-joined zirconia abutment with different angle loading for clinical applications. The inter-joined abutments were shaped with the technique of injection of zirconia powder in nanometers. Sixty Osstem GSII 5 × 10 mm implants were used with 30 zirconia abutments and 30 Osstem GSII titanium abutments for fixation using 40 N torque force. The loading applications included 90°, 30°, and 0° formed by the long axis of abutments and pressure head of universal test machine. The fracture resistances of zirconia and titanium abutments were documented and analyzed. The inter-joined zirconia abutments were assembled to the Osstem GSII implants successfully. In the 90° loading mode, the fracture resistance of zirconia abutment group and titanium abutment group were 301.5 ± 15.4 N and 736.4 ± 120.1 N, respectively. And those in the 30° groups were 434.7 ± 36.1 N and 1073.1 ± 74 N, correspondingly. Significant difference in the two groups was found using t-test and Wilcoxon test. No damage on the abutments of the two groups but S-shaped bending on the implants was found when the 0° loading was 1300-2000 N. Through the assembly of Zirconia abutments and implants, all the components presented sufficient resistance acquired for the clinical application under loadings with different angle. © 2012 John Wiley & Sons A/S.
Bhargava, Ragini; Carson, Caree R; Lee, Gabriella; Stark, Jeremy M
2017-01-24
A likely mechanism of chromosomal rearrangement formation involves joining the ends from two different chromosomal double-strand breaks (DSBs). These events could potentially be mediated by either of two end-joining (EJ) repair pathways [canonical nonhomologous end joining (C-NHEJ) or alternative end joining (ALT-EJ)], which cause distinct rearrangement junction patterns. The relative role of these EJ pathways during rearrangement formation has remained controversial. Along these lines, we have tested whether the DNA damage response mediated by the Ataxia Telangiectasia Mutated (ATM) kinase may affect the relative influence of C-NHEJ vs. ALT-EJ on rearrangement formation. We developed a reporter in mouse cells for a 0.4-Mbp deletion rearrangement that is formed by EJ between two DSBs induced by the Cas9 endonuclease. We found that disruption of the ATM kinase causes an increase in the frequency of the rearrangement as well as a shift toward rearrangement junctions that show hallmarks of C-NHEJ. Furthermore, ATM suppresses rearrangement formation in an experimental condition, in which C-NHEJ is the predominant EJ repair event (i.e., expression of the 3' exonuclease Trex2). Finally, several C-NHEJ factors are required for the increase in rearrangement frequency caused by inhibition of the ATM kinase. We also examined ATM effectors and found that H2AX shows a similar influence as ATM, whereas the influence of ATM on this rearrangement seems independent of 53BP1. We suggest that the contribution of the C-NHEJ pathway to the formation of a 0.4-Mbp deletion rearrangement is enhanced in ATM-deficient cells.
1995-05-01
ForeSight ( MECFS ). Prior to joining TASC, Mr. Stanzione served as the deputy director of the Semi-Automated Forces group at Loral Advanced Distributed...TASC’s other Synthetic Environment programs, including Weather in DIS (WINDS) and Multi-Echelon CFOR with ForeSight ( MECFS ). Prior to joining TASC, Mr
Fabrication technology: A compilation
NASA Technical Reports Server (NTRS)
1974-01-01
A compilation is presented which supplies technical information on the assembly of diverse components into functional assemblies and subassemblies, as well as information on several fasteners and fastening techniques that join components, subassemblies, and complete assemblies to achieve a functional unit. Quick-disconnect fasteners are described, along with several devices and methods for attaching thermal insulators, and for joining and separating objects in the absence of gravity.
JPRS Report, Soviet Union, International Affairs.
1987-07-08
SDI, Japan evidently is counting on joining in the advertised technical and technological innovations that are supposedly anticipated in the course...specific results of this program are irreconcilably far from the illusory advantages advertised by the United States before they joined it: England...functioning of bourgeois democracy, alien in spirit to traditional ideological institutions and behavioral stereotypes ), we should come to the conclusion
The Impact Of Middle Class Consumption On Democratization In Northeast Asia
2016-03-01
middle-class Koreans. This consumption disparity caused the structurally disadvantaged working-class Koreans to join national protests that ultimately...inequality and a mobility-restraining household registration system. There exists a key political tension around structurally disadvantaged Chinese migrant...lower middle-class Koreans. This consumption disparity caused the structurally disadvantaged working-class Koreans to join national protests that
NREL's Hydrogen Fueling Infrastructure Research: Year in Review | News |
) joins others across the United States to celebrate National Hydrogen and Fuel Cell Day on Oct. 8-10.08-a NREL joined the Colorado hydrogen community for a National Hydrogen and Fuel Cell Day event at the governor proclaiming Oct. 8, 2016, as Hydrogen and Fuel Cell Day in Colorado, and the adoption of a new
ERIC Educational Resources Information Center
Al Habahbeh, Abdullah Eid
2014-01-01
This study aimed at knowing the motives of students' joining master program at Princess Alia University College/Al Balqa Applied University by the graduate students and a degree of their importance and succession, and to know whether these motives differed according to the variables of gender, specialization, age, and marital status. To achieve…
7. Elevation view of east side of building where the ...
7. Elevation view of east side of building where the 1896 south section (left) joins the 1904 middle section. When joined with photo WA-116-A-6, these photos give a virtually complete elevation view of the east side of the 1896 south section of Building 59. - Puget Sound Naval Shipyard, Pattern Shop, Farragut Avenue, Bremerton, Kitsap County, WA
NASA Technical Reports Server (NTRS)
Staugaitis, C. L. (Editor)
1975-01-01
Materials which have demonstrated their suitability for space application are summarized. Common, recurring problems in encapsulants and conformal coatings, optical materials, lubrication, and bonding and joining are noted. The subjects discussed include: low density and syntactic foams, electrical encapsulants; optical glasses, interference filter, mirrors; oils, greases, lamillar lubricants; and, soldering and brazing processes.
Talking to Foucault: Examining Marginalization and Exclusion in Academic Science
ERIC Educational Resources Information Center
McClam, Sherie
2006-01-01
In this article, the author invites everyone to join her as she follows Laurel Richardson's advice to use writing as a method of inquiry. To do so, she engages in a fictional conversation with Michel Foucault--later joined by actor-network theorist Michel Callon--in which she talks through and constructs understanding(s) of and from her research…
ERIC Educational Resources Information Center
Ferráns, Silvia Diazgranados; Selman, Robert L.
2014-01-01
The authors of this article, Silvia Diazgranados Ferráns and Robert Selman, use an emergent framework to explore how the rules of the school culture at different perceived school climates affect early adolescents' decisions to upstand, bystand, or join the perpetrators when they witness peer aggression and bullying. Through a grounded theory…
Fermilab Friends for Science Education | Join Us
Fermilab Prairie photo Saturday, September 17, 2011; 9:30 AM - 12:30 PM Have you ever walked through a native tallgrass forbs and grasses. As a member of FFSE, you are invited to a members-only tour of this rare ecosystem. Join prairie experts on a tour of the Margaret Pearson Interpretive Trail and the
HCA Voices Make Council Debut.
Cardwell, David
2012-11-28
I have been an RCN member since 2002 when healthcare assistants (HCAs) had to have an NVQ level 3 to join - so I got one. Soon after, with encouragement from the general secretary and chair of congress, I was the first HCA to vote and speak at RCN congress - in a speech in favour of nursery nurses joining the RCN with an NVQ level 2 qualification.
Improvement of the reliability of laser beam microwelding as interconnection technique
NASA Astrophysics Data System (ADS)
Glasmacher, Mathias; Pucher, Hans-Joerg; Geiger, Manfred
1996-04-01
The requirements of actual trends for joining within modern electronics production can be met with the technique of laser beam micro welding, which is the topic of this paper. Thereby component leads are welded directly to the conducting tracks of the circuit board. This technique is not limited to electronics, because fine mechanical parts can be joined with the same equipment, too. The advantages as high temperature strength, reduced manufacturing time and simplified material separation at the end of the life cycle are noted. Furthermore the drawbacks of laser beam micro welding as a competitive joining technique to soldering are discussed. The reasons for the unstable process behavior of different welding scenarios can be understood by taking the changes of some process parameters into account. Since the process reliability can be improved by a proper process design as well as by closed-loop-control, results of finite element calculations of the temperature field as well as experimental setup for the determination of the melting point are presented. Future work is stated to spread the applicability of this joining technique as well as to develop an on-line control for high performance welding of locally restricted structures.
NASA Astrophysics Data System (ADS)
Zheng, Yan
2015-03-01
Internet of things (IoT), focusing on providing users with information exchange and intelligent control, attracts a lot of attention of researchers from all over the world since the beginning of this century. IoT is consisted of large scale of sensor nodes and data processing units, and the most important features of IoT can be illustrated as energy confinement, efficient communication and high redundancy. With the sensor nodes increment, the communication efficiency and the available communication band width become bottle necks. Many research work is based on the instance which the number of joins is less. However, it is not proper to the increasing multi-join query in whole internet of things. To improve the communication efficiency between parallel units in the distributed sensor network, this paper proposed parallel query optimization algorithm based on distribution attributes cost graph. The storage information relations and the network communication cost are considered in this algorithm, and an optimized information changing rule is established. The experimental result shows that the algorithm has good performance, and it would effectively use the resource of each node in the distributed sensor network. Therefore, executive efficiency of multi-join query between different nodes could be improved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Henager, Charles H.; Nguyen, Ba Nghiep; Kurtz, Richard J.
2015-06-30
The international fusion community designed miniature torsion specimens for joint testing and irradiation in test reactors with limited irradiation volumes since SiC and SiC-composites used in fission or fusion environments require joining methods for assembling systems. Torsion specimens fail out-of-plane when joints are strong and when elastic moduli are comparable to SiC, which causes difficulties in determining shear strengths for many joints or for comparing unirradiated and irradiated joints. A finite element damage model was developed to treat elastic joints such as SiC/Ti3SiC2+SiC and elastic-plastic joints such as SiC/epoxy and steel/epoxy. The model uses constitutive shear data and is validatedmore » using epoxy joint data. The elastic model indicates fracture is likely to occur within the joined pieces to 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. Lower modulus epoxy joints always fail in plane and provide good model validation.« less
Boubakour-Azzouz, Imenne; Ricchetti, Miria
2008-02-01
Efficient and faithful repair of DNA double-strand breaks (DSBs) is critical for genome stability. To understand whether cells carrying a functional repair apparatus are able to efficiently heal two distant chromosome ends and whether this DNA lesion might result in genome rearrangements, we induced DSBs in genetically modified mouse embryonic stem cells carrying two I-SceI sites in cis separated by a distance of 9 kbp. We show that in this context non-homologous end-joining (NHEJ) can repair using standard DNA pairing of the broken ends, but it also joins 3' non-complementary overhangs that require unusual joining intermediates. The repair efficiency of this lesion appears to be dramatically low and the extent of genome alterations was high in striking contrast with the spectra of repair events reported for two collinear DSBs in other experimental systems. The dramatic decline in accuracy suggests that significant constraints operate in the repair process of these distant DSBs, which may also control the low efficiency of this process. These findings provide important insights into the mechanism of repair by NHEJ and how this process may protect the genome from large rearrangements.
NASA Astrophysics Data System (ADS)
Marisarla, Soujanya; Ghia, Urmila; "Karman" Ghia, Kirti
2002-11-01
Towards a comprehensive aeroelastic analysis of a joined wing, fluid dynamics and structural analyses are initially performed separately. Steady flow calculations are currently performed using 3-D compressible Navier-Stokes equations. Flow analysis of M6-Onera wing served to validate the software for the fluid dynamics analysis. The complex flow field of the joined wing is analyzed and the prevailing fluid dynamic forces are computed using COBALT software. Currently, these forces are being transferred as fluid loads on the structure. For the structural analysis, several test cases were run considering the wing as a cantilever beam; these served as validation cases. A nonlinear structural analysis of the wing is being performed using ANSYS software to predict the deflections and stresses on the joined wing. Issues related to modeling, and selecting appropriate mesh for the structure were addressed by first performing a linear analysis. The frequencies and mode shapes of the deformed wing are obtained from modal analysis. Both static and dynamic analyses are carried out, and the results obtained are carefully analyzed. Loose coupling between the fluid and structural analyses is currently being examined.
Transient liquid phase ceramic bonding
Glaeser, Andreas M.
1994-01-01
Ceramics are joined to themselves or to metals using a transient liquid phase method employing three layers, one of which is a refractory metal, ceramic or alloy. The refractory layer is placed between two metal layers, each of which has a lower melting point than the refractory layer. The three layers are pressed between the two articles to be bonded to form an assembly. The assembly is heated to a bonding temperature at which the refractory layer remains solid, but the two metal layers melt to form a liquid. The refractory layer reacts with the surrounding liquid and a single solid bonding layer is eventually formed. The layers may be designed to react completely with each other and form refractory intermetallic bonding layers. Impurities incorporated into the refractory metal may react with the metal layers to form refractory compounds. Another method for joining ceramic articles employs a ceramic interlayer sandwiched between two metal layers. In alternative embodiments, the metal layers may include sublayers. A method is also provided for joining two ceramic articles using a single interlayer. An alternate bonding method provides a refractory-metal oxide interlayer placed adjacent to a strong oxide former. Aluminum or aluminum alloys are joined together using metal interlayers.
Gasket Assembly for Sealing Mating Surfaces
NASA Technical Reports Server (NTRS)
Bryant, Melvin A., III (Inventor)
2003-01-01
A pair of substantially opposed mating surfaces are joined to each other and sealed in place by means of an electrically-conductive member which is placed in proximity to the mating surfaces. The electrically-conductive member has at least one element secured thereto which is positioned to contact the mating surfaces, and which softens when the electrically-conductive member is heated by passing an electric current therethrough. The softened element conforms to the mating surfaces, and upon cooling of the softened element the mating surfaces are joined together in an effective seal. Of particular significance is an embodiment of the electrically-conductive member which is a gasket having an electrically-conductive gasket base and a pair of the elements secured to opposite sides of the gasket base. This embodiment is positioned between the opposed mating surfaces to be joined to each other. Also significant is an embodiment of the electrically-conductive member which is an electrically-conductive sleeve having an element secured to its inner surface. This embodiment surrounds cylindrical members the bases of which are the substantially opposed mating surfaces to be joined, and the element on the inner surface of the sleeve contacts the outer surfaces of the cylindrical members.
NASA Astrophysics Data System (ADS)
Schreiber, S.; Zaeh, M. F.
2018-06-01
Reactive particles represent a promising alternative for effectively joining components with freeform surfaces and different material properties. While the primary application of reactive systems is combustion synthesis for the production of high-performance alloys, the highly exothermic reaction can also be used to firmly bond thermosensitive joining partners. Core-shell structures are of special interest, since they function as separate microreactors. In this paper, a method to synthesise reactive nickel-aluminium core-shell structures via a two-step plating process is described. Based on an electroless process, the natural oxide layer of the aluminium particles is removed and substituted with a thin layer of nickel. Subsequently, the pre-treated particles are electroplated with nickel. The high reactivity of aluminium and the oxide layer play a significant role in adjusting the process parameters of the Watts bath. Additionally, the developed experimental set-up is introduced and the importance of process control is shown. In order to achieve reproducible results, the electroplating process was automated. Ignition tests with electromagnetic waves demonstrated that the particles undergo an exothermic reaction. Therefore, they can be used as a heat source in thermal joining applications.
Development of forming and joining technology for TD-NiCr sheet
NASA Technical Reports Server (NTRS)
Torgerson, R. T.
1973-01-01
Forming joining techniques and properties data were developed for thin-gage TD-NiCr sheet in the recrystallized and unrecrystallized conditions. Theoretical and actual forming limit data are presented for several gages of each type of material for five forming processes: brake forming, corrugation forming, joggling, dimpling and beading. Recrystallized sheet can be best formed at room temperature, but unrecrystallized sheet requires forming at elevated temperature. Formability is satisfactory with most processes for the longitudinal orientation but poor for the transverse orientation. Dimpling techniques require further development for both material conditions. Data on joining techniques and joint properties are presented for four joining processes: resistance seam welding (solid-state), resistance spot welding (solid-state), resistance spot welding (fusion) and brazing. Resistance seam welded (solid-state) joints with 5t overlap were stronger than parent material for both material conditions when tested in tensile-shear and stress-rupture. Brazing studies resulted in development of NASA 18 braze alloy (Ni-16Cr-15Mo-8Al-4Si) with several properties superior to baseline TD-6 braze alloy, including lower brazing temperture, reduced reaction with Td-Ni-Cr, and higher stress-rupture properties.
Electrofriction method of manufacturing squirrel cage rotors
DOE Office of Scientific and Technical Information (OSTI.GOV)
Hsu, John S.
2005-04-12
A method of making a squirrel cage rotor of copper material for use in AC or DC motors, includes forming a core with longitudinal slots, inserting bars of conductive material in the slots, with ends extending out of opposite ends of the core, and joining the end rings to the bars, wherein the conductive material of either the end rings or the bars is copper. Various methods of joining the end rings to the bars are disclosed including electrofriction welding, current pulse welding and brazing, transient liquid phase joining and casting. Pressure is also applied to the end rings tomore » improve contact and reduce areas of small or uneven contact between the bar ends and the end rings. Rotors made with such methods are also disclosed.« less
Laser Welding Dissimilar Reflective Alloys
NASA Technical Reports Server (NTRS)
Mccay, M. H.; Gopinathan, S.; Kahlen, F.; Speigel, L.
1993-01-01
This project, jointly sponsored by Rocketdyne and CSTAR, involves the development of laser joining of materials which have heretofore been impractical to bond. Of particular interest are joints between stainless steel and copper and also aluminum 6061 to aluminum 2219. CSTAR has a unique opportunity in this area since both the process and development and diagnostics are of interest to industry. Initial results using the pulse tailored laser welding technique developed in CLA for joining crack sensitive materials have proven promising for the aluminum joints based upon metallurgical and electronic microprobe analysis. A declaration of success requires additional mechanical testing. A CW technique has been applied to the stainless-copper joining with some preliminary success. These joints are of significant interest for aeronautics and rocket propulsion applications and the project is expected to continue.
Multicolor printing plate joining
NASA Technical Reports Server (NTRS)
Waters, W. J. (Inventor)
1984-01-01
An upper plate having ink flow channels and a lower plate having a multicolored pattern are joined. The joining is accomplished without clogging any ink flow paths. A pattern having different colored parts and apertures is formed in a lower plate. Ink flow channels each having respective ink input ports are formed in an upper plate. The ink flow channels are coated with solder mask and the bottom of the upper plate is then coated with solder. The upper and lower plates are pressed together at from 2 to 5 psi and heated to a temperature of from 295 F to 750 F or enough to melt the solder. After the plates have cooled and the pressure is released, the solder mask is removed from the interior passageways by means of a liquid solvent.
Structural optimization for joined-wing synthesis
NASA Technical Reports Server (NTRS)
Gallman, John W.; Kroo, Ilan M.
1992-01-01
The differences between fully stressed and minimum-weight joined-wing structures are identified, and these differences are quantified in terms of weight, stress, and direct operating cost. A numerical optimization method and a fully stressed design method are used to design joined-wing structures. Both methods determine the sizes of 204 structural members, satisfying 1020 stress constraints and five buckling constraints. Monotonic splines are shown to be a very effective way of linking spanwise distributions of material to a few design variables. Both linear and nonlinear analyses are employed to formulate the buckling constraints. With a constraint on buckling, the fully stressed design is shown to be very similar to the minimum-weight structure. It is suggested that a fully stressed design method based on nonlinear analysis is adequate for an aircraft optimization study.
Practical small-scale explosive seam welding
NASA Technical Reports Server (NTRS)
Bement, L. J.
1983-01-01
A small-scale explosive seam welding process has been developed that can significantly contribute to remote metal joining operations under hazardous or inaccessible conditions, such as nuclear reactor repair and assembly of structure in space. This paper describes this explosive seam welding process in terms of joining principles, variables, types of joints created, capabilities, and applications. Very small quantities of explosive in a ribbon configuration are used to create narrow (less than 0.5 inch), long-length, uniform, hermetically sealed joints that exhibit parent metal properties in a wide variety of metals, alloys, and combinations. The practicality of this process has been demonstrated by its current acceptance, as well as its capabilities that are superior in many applications to the universally accepted joining processes, such as mechanical fasteners, fusion and resistance welding, and adhesives.
Laser welding dissimilar reflective alloys
NASA Astrophysics Data System (ADS)
McCay, M. H.; Gopinathan, S.; Kahlen, F.; Speigel, L.
1993-01-01
This project, jointly sponsored by Rocketdyne and CSTAR, involves the development of laser joining of materials which have heretofore been impractical to bond. Of particular interest are joints between stainless steel and copper and also aluminum 6061 to aluminum 2219. CSTAR has a unique opportunity in this area since both the process and development and diagnostics are of interest to industry. Initial results using the pulse tailored laser welding technique developed in CLA for joining crack sensitive materials have proven promising for the aluminum joints based upon metallurgical and electronic microprobe analysis. A declaration of success requires additional mechanical testing. A CW technique has been applied to the stainless-copper joining with some preliminary success. These joints are of significant interest for aeronautics and rocket propulsion applications and the project is expected to continue.
Dissimilar Brazed Joints Between Steel and Tungsten Carbide
NASA Astrophysics Data System (ADS)
Voiculescu, I.; Geanta, V.; Binchiciu, H.; Iovanas, D.; Stefanoiu, R.
2017-06-01
Brazing is a joining process used to obtain heterogeneous assemblies between different materials, such as steels, irons, non-ferrous metals, ceramics etc. Some application, like asphalt cutters, require quick solutions to obtain dissimilar joints at acceptable costs, given the very short period of operation of these parts. This paper presents some results obtained during the brazing of dissimilar joints between steel and tungsten carbide by using different types of Ag-Cu system filler materials alloyed with P and Sn. The brazing techniques used were oxygen-gas flame and induction joining. The brazing behaviour was analysed in cross sections by optical and electron microscopy. The metallographic analysis enhanced the adhesion features and the length of penetration in the joining gap. The melting range of the filler materials was measured using thermal analysis.
Affordable, Robust Ceramic Joining Technology (ARCJoinT) Given 1999 R and D 100 Award
NASA Technical Reports Server (NTRS)
Singh, Mrityunjay
2000-01-01
Advanced ceramics and fiber-reinforced ceramic matrix composites with high strength and toughness, good thermal conductivity, thermal shock resistance, and oxidation resistance are needed for high-temperature structural applications in advanced high-efficiency and high-performance engines, space propulsion components, and land-based systems. The engineering designs of these systems require the manufacturing of large parts with complex shapes, which are either quite expensive or impossible to fabricate. In many instances, it is more economical to build complex shapes by joining together simple geometrical shapes. Thus, joining has been recognized as an enabling technology for the successful utilization of advanced ceramics and fiber-reinforced composite components in high-temperature applications. However, such joints must retain their structural integrity at high temperatures and must have mechanical strength and environmental stability comparable to those of the bulk materials. In addition, the joining technique should be robust, practical, and reliable. ARCJoinT, which is based on the reaction-forming approach, is unique in terms of producing joints with tailorable microstructures. The formation of joints by this approach is attractive since the thermomechanical properties of the joint interlayer can be tailored to be very close to those of the base materials. In addition, high-temperature fixturing is not needed to hold the parts at the infiltration temperature. The joining process begins with the application of a carbonaceous mixture in the joint area, holding the items to be joined in a fixture, and curing at 110 to 120 C for 10 to 20 min. This step fastens the pieces together. Then, silicon or a silicon alloy in tape, paste, or slurry form is applied around the joint region and heated to 1250 to 1425 C (depending on the type of infiltrant) for 10 to 15 min. The molten silicon or silicon-refractory metal alloy reacts with carbon to form silicon carbide with controllable amounts of silicon and other phases as determined by the alloy composition. Joint thickness can be readily controlled through adjustments of the properties of the carbonaceous paste and the applied fixturing force. The photograph shows various shapes of silicon-carbide-based ceramics and fiberreinforced composites that have been joined using ARCJoinT. Thermomechanical and thermochemical characterization of joints is underway for a wide variety of silicon-carbidebased advanced ceramics and fiber-reinforced composites under the hostile environments that will be encountered in engine applications. ARCJoinT, which was developed by researchers at the NASA Glenn Research Center at Lewis Field, received R&D Magazine's prestigious R&D 100 Award in 1999.
Evaluating the Upset Protrusion Joining (UPJ) Method to Join Magnesium Castings to Dissimilar Metals
DOE Office of Scientific and Technical Information (OSTI.GOV)
Logan, Stephen
2016-02-24
This presentation discusses advantages and best practices for incorporating magnesium in automotive component applications to achieve substantial mass reduction, as well as some of the key challenges with respect to joining, coating, and galvanic corrosion, before providing an introduction and status update of the U.S. Department of Energy and Department of Defense jointly sponsored Upset Protrusion Joining (UPJ) process development and evaluation project. This update includes sharing performance results of a benchmark evaluation of the self-pierce riveting (SPR) process for joining dissimilar magnesium (Mg) to aluminum (Al) materials in four unique coating configurations before introducing the UPJ concept and comparingmore » performance results of the joints made with the UPJ process to those made with the SPR process. Key results presented include: The benchmark SPR process can produce good joints in the MgAM60B-Al 6013 joint configuration with minimal cracking in the Mg coupons if the rivet is inserted from the Mg side into the Al side; Numerous bare Mg to bare Al joints made with the SPR process separated after only 6-wks of accelerated corrosion testing due to fracture of the rivet as a result of hydrogen embrittlement; For the same joint configurations, UPJ demonstrated substantially higher pre-corrosion joint strengths and post-corrosion joint strengths, primarily because of the larger diameter protrusion compared to smaller SPR rivet diameter and reduced degradation due to accelerated corrosion exposure; As with the SPR process, numerous bare Mg to bare Al joints made with the UPJ process also separated after 6-wks of accelerated corrosion testing, but unlike the SPR experience, the UPJ joints experienced degradation of the boss and head because of galvanic corrosion of the Mg casting, not hydrogen embrittlement of the steel rivet; In the configuration where both the Mg and Al were pretreated with Alodine 5200 prior to joining and the complete assembly was powder-coated afterwards, the UPJ process showed substantial improvement in corrosion performance compared to SPR where many SPR joints had separated after only 6-wks of exposure, but none of the UPJ joints had separated even after 8-wis; and In the cases where the Al panel was coated prior to joining to the pretreated Mg coupons, neither the SPR or UPJ joints showed any joint separation or substantial joint performance degradation even after 12-wks of accelerated corrosion exposure.« less
Romano, Michael
2003-07-21
The power of religion and the might of physicians seem to have joined forces against Baptist Health System's proposed merger with for-profit Triad Hospitals. Doctors and employees of Baptist facilities such as Montclair Baptist Medical Center, left, demanded that the system remain faith-based and under local control.
Advanced Metalworking Solutions For Naval Systems That Go In Harm’s Way
2015-01-01
destroyers USS Momsen (DDG 92) and USS Preble (DDG 88) are underway in formation. U.S. Navy photo Front cover: Ingalls Shipbuilding welding photo...applies a variety of innovative welding technologies to address the challenges associated with joining weapon system components. Joining Technologies...friction stir welding process to manufacture edge-cooled naval electronic cold plate assemblies. The modular, high- performance, and scalable
ERIC Educational Resources Information Center
Join Together, Boston, MA.
Join Together convened a panel of experts to review U.S. policies for addiction treatment and recovery. Although the panel reached an agreement on six recommendations for policy changes that can make help more accessible and expand treatment to more people. These recommendations are: (1) treatment for alcoholism and other drug addiction must be…
Coupling for joining a ball nut to a machine tool carriage
Gerth, Howard L.
1979-01-01
The present invention relates to an improved coupling for joining a lead screw ball nut to a machine tool carriage. The ball nut is coupled to the machine tool carriage by a plurality of laterally flexible bolts which function as hinges during the rotation of the lead screw for substantially reducing lateral carriage movement due to wobble in the lead screw.
Splicing Wires Permanently With Explosives
NASA Technical Reports Server (NTRS)
Bement, Laurence J.; Kushnick, Anne C.
1990-01-01
Explosive joining process developed to splice wires by enclosing and metallurgically bonding wires within copper sheets. Joints exhibit many desirable characteristics, 100-percent conductivity and strength, no heat-induced annealing, no susceptibility to corrosion in contacts between dissimilar metals, and stability at high temperature. Used to join wires to terminals, as well as to splice wires. Applicable to telecommunications industry, in which millions of small wires spliced annually.
ERIC Educational Resources Information Center
Southern Regional Education Board (SREB), 2011
2011-01-01
The Texas Education Agency (TEA) and the Southern Regional Education Board (SREB) joined hands in 2005 to enhance dramatically implementation of the "High Schools That Work" ("HSTW") improvement design in the state. Between 2005 and 2010, nearly 50 high schools in five cohorts joined the Texas Enhanced "HSTW" Network…
Renew or Join R&W Club Frederick for 2014 | Poster
By Carolynne Keenan, Contributing Writer If you want to meet new people and participate in new activities in 2014, don’t forget to renew or join the Recreation and Welfare (R&W) Club Frederick. Membership is $9 for the calendar year. An R&W Club Frederick membership offers discounts at local businesses, the opportunity to participate in events and activities (which are often
Intentions of Women (18-25 Years Old) to Join the Military: Results of a National Survey.
ERIC Educational Resources Information Center
Borack, Jules I.
In anticipation of the projected decline in the national population of young men and of expanding the role of women in the military, the Navy conducted a national telephone survey to gauge the interest of women and men in joining the military under present conditions and under three alternative options. The options related to expanding the role of…
ERIC Educational Resources Information Center
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…
Multiply Your Child's Success: Math and Science Can Make Dreams Come True. A Parent's Guide
ERIC Educational Resources Information Center
National Math and Science Initiative, 2012
2012-01-01
In today's high-tech world, math and science matter. Of the 10 fastest growing occupations, eight are science, math or technology-related. Whatever a child wants to do--join the military, join the workforce, or go on to college--math and science skills will be important. Become part of the equation to help one's child succeed now and in the…
Technological Advances in Joining
1981-08-01
automotive industry, and similar robots are being equipped to perform many arc welding functions in areas where high production rates must be...nonvacuum electron-beam welding favor the use of this process by the automotive industry. For example, this process has been used to join the component...metal additions were not needed. This process has been also used to weld various assemblies for automotive transmissions (e.g., annulus gear assemblies
Astronaut Crippen prepares to join crew in training
1984-09-04
41D-3186 (4 Sept 1984) --- Astronaut Robert L. Crippen, 41-G crew commander, prepares to join his six fellow crewmembers for some training in the mockup and integration laboratory at the Johnson Space Center. Astronaut David C. Leestma, 41-G mission specialist, left, will participate in a scheduled extravehicular activity (EVA) on the Challenger's next mission. Today's training is for launch phase procedures.
ERIC Educational Resources Information Center
Winkler, Matthew J.
2014-01-01
The purpose of this qualitative study is to examine the pre-college factors, attitudes, and experiences of black men who joined traditionally white fraternities (TWFs) at large public predominantly white institutions (PWIs) over approximately the past four decades. These factors, with special emphasis on issues of identity, self- and group-esteem,…
1982-04-01
processes requiring systematic experimental analysis. Accordingly, group performance effectiveness studies were initiated to 61 assess the effects on...the experiment. 67 active processes associated with Joining the respective established groups, but the absence of baseline levels precludes such an...novitiate in comparison to such values observed during baseline days suggested an active process associated with the joining of the group and emphasized the
Interactive training model of TRIZ for mechanical engineers in China
NASA Astrophysics Data System (ADS)
Tan, Runhua; Zhang, Huangao
2014-03-01
Innovation is a process of taking an original idea and converting it into a business value, in which the engineers face some inventive problems which can be solved hardly by experience. TRIZ, as a new theory for companies in China, provides both conceptual and procedural knowledge for finding and solving inventive problems. Because the government plays a leading role in the diffusion of TRIZ, too many companies from different industries are waiting to be trained, but the quantity of the trainers mastering TRIZ is incompatible with that requirement. In this context, to improve the training effect, an interactive training model of TRIZ for the mechanical engineers in China is developed and the implementation in the form of training classes is carried out. The training process is divided into 6 phases as follows: selecting engineers, training stage-1, finding problems, training stage-2, finding solutions and summing up. The government, TRIZ institutions and companies to join the programs interact during the process. The government initiates and monitors a project in form of a training class of TRIZ and selects companies to join the programs. Each selected companies choose a few engineers to join the class and supervises the training result. The TRIZ institutions design the training courses and carry out training curriculum. With the beginning of the class, an effective communication channel is established by means of interview, discussion face to face, E-mail, QQ and so on. After two years training practices, the results show that innovative abilities of the engineers to join and pass the final examinations increased distinctly, and most of companies joined the training class have taken congnizance of the power of TRIZ for product innovation. This research proposes an interactive training model of TRIZ for mechanical engineers in China to expedite the knowledge diffusion of TRIZ.
Wang, Xi; Sun, Lixing; Li, Jinhua; Xia, Dongpo; Sun, Binghua; Zhang, Dao
2015-01-01
Collective behavior has recently attracted a great deal of interest in both natural and social sciences. While the role of leadership has been closely scrutinized, the rules used by joiners in collective decision making have received far less attention. Two main hypotheses have been proposed concerning these rules: mimetism and quorum. Mimetism predicts that individuals are increasingly likely to join collective behavior as the number of participants increases. It can be further divided into selective mimetism, where relationships among the participants affect the process, and anonymous mimetism, where no such effect exists. Quorum predicts that a collective behavior occurs when the number of participants reaches a threshold. To probe into which rule is used in collective decision making, we conducted a study on the joining process in a group of free-ranging Tibetan macaques (Macaca thibetana) in Huangshan, China using a combination of all-occurrence and focal animal sampling methods. Our results show that the earlier individuals joined movements, the more central a role they occupied among the joining network. We also found that when less than three adults participated in the first five minutes of the joining process, no entire group movement occurred subsequently. When the number of these early joiners ranged from three to six, selective mimetism was used. This means higher rank or closer social affiliation of early joiners could be among the factors of deciding whether to participate in movements by group members. When the number of early joiners reached or exceeded seven, which was the simple majority of the group studied, entire group movement always occurred, meaning that the quorum rule was used. Putting together, Macaca thibetana used a combination of selective mimetism and quorum, and early joiners played a key role in deciding which rule should be used.
Margitai, Barnabás; Dózsa, Csaba; Bárdos-Csenteri, Orsolya Karola; Sándor, János; Gáll, Tibor; Gődény, Sándor
2018-01-01
Objective Quantitative studies have shown the various benefits for having accreditation in hospitals. However, neither of these explored the general conditions before applying for an accreditation. To close this gap, this study aimed to investigate the possible association between joining an accreditation programme with various hospital characteristics. Design A cross-sectional study was implemented using the databases of the 2013 Hungarian hospital survey and of the Hungarian State Treasury. Setting Public general hospitals in Hungary. Participants The analysis involved 44 public general hospitals, 14 of which joined the preparatory project for a newly developed accreditation programme. Main outcome measures The outcomes included the percentage of compliance in quality management, patient information and identification, internal professional regulation, safe surgery, pressure sore prevention, infection control, the opinions of the heads of quality management regarding the usefulness of quality management and clinical audits, and finally, the total debt of the hospital per bed and per discharged patient. Results According to our findings, the general hospitals joining the preparatory project of the accreditation programme performed better in four of the six investigated activities, the head of quality management had a better opinion on the usefulness of quality management, and both the debt per bed number and the debt per discharged patient were lower than those who did not join. However, no statistically significant differences between the two groups were found in any of the examined outcomes. Conclusions The findings suggest that hospitals applying for an accreditation programme do not differ significantly in characteristics from those which did not apply. This means that if in the future the accredited hospitals become better than other hospitals, then the improvement could be solely contributed to the accreditation. PMID:29391381
Summary of Prior Work on Joining of Oxide Dispersion-Strengthened Alloys
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wright, Ian G; Tatlock, Gordon J; Badairy, H.
2009-08-01
There is a range of joining techniques available for use with ODS alloys, but care should be exercised in matching the technique to the final duty requirements of the joint. The goal for joining ODS alloys is a joint with no local disruption of the distribution of the oxide dispersion, and no significant change in the size and orientation of the alloy microstructure. Not surprisingly, the fusion welding processes typically employed with wrought alloys produce the least satisfactory results with ODS alloys, but some versions, such as fusion spot welding, and the laser and electron-beam welding technologies, have demonstrated potentialmore » for producing sound joints. Welds made using solid-state spot welding reportedly have exhibited parent metal properties. Thus, it is possible to employ processes that result in significant disruption of the alloy microstructure, as long as the processing parameters are adjustment to minimize the extent of or influence of the changes in the alloy microstructure. Selection among these joining approaches largely depends on the particular application and component configuration, and an understanding of the relationships among processing, alloy microstructure, and final properties is key. Recent developments have resulted in friction welding evolving to be a prime method for joining ODS sheet products, and variants of brazing/diffusion bonding have shown excellent promise for use with tubes and pipes. The techniques that come closest to the goal defined above involve solid-state diffusion bonding and, in particular, it has been found that secondary recrystallization of joints made by pulsed plasma-assisted diffusion can produce the desired, continuous, large alloy grain structure through the joint. Such joints have exhibited creep rupture failure at >82% of the load needed to fail the monolithic parent alloy at 1000 C.« less
NASA Technical Reports Server (NTRS)
Witt, R. H.
1972-01-01
Requirements for advanced aircraft have led to more extensive use of titanium alloys and the resultant search for joining processes which can produce lightweight, high strength airframe structures efficiently. As a result, electron beam welding has been investigated. The following F-14A components are now being EB welded in production and are mainly annealed Ti-6Al-4V except for the upper wing cover which is annealed Ti-6Al-6V-2Sn: F-14A wing center section box, and F-14A lower and upper wing covers joined to wing pivot fitting assemblies. Criteria for selection of welding processes, the EB welding facility, development work on EB welding titanium alloys, and F-14A production and sliding seal electron beam welding are reported.
Joining dissimilar materials using Friction Stir scribe technique
DOE Office of Scientific and Technical Information (OSTI.GOV)
Upadhyay, Piyush; Hovanski, Yuri; Jana, Saumyadeep
2016-10-03
The ability to effectively join materials with vastly different melting points like Aluminum-Steel, Polymer composites - metals has been one of the road blocks in realizing multi-material components for light weighting efforts. Friction stir scribe (FSS) technique is a promising method that produces continuous overlap joint between materials with vastly different melting regimes and high temperature flow characteristics. FSS uses an offset cutting tool at the tip of the FSW pin to create an insitu mechanical interlock between material interfaces. With investments from Vehicle Technology office, US DOE and several automotive manufacturers and suppliers PNNL is developing the FSS processmore » and has demonstrated viability of joining several material combinations. Details of welding trails, unique challenges and mitigation strategies in different material combinations will be discussed. Joint characterization including mechanical tests and joint performances will also be presented.« less
Repair of Double-Strand Breaks by End Joining
Chiruvella, Kishore K.; Liang, Zhuobin; Wilson, Thomas E.
2013-01-01
Nonhomologous end joining (NHEJ) refers to a set of genome maintenance pathways in which two DNA double-strand break (DSB) ends are (re)joined by apposition, processing, and ligation without the use of extended homology to guide repair. Canonical NHEJ (c-NHEJ) is a well-defined pathway with clear roles in protecting the integrity of chromosomes when DSBs arise. Recent advances have revealed much about the identity, structure, and function of c-NHEJ proteins, but many questions exist regarding their concerted action in the context of chromatin. Alternative NHEJ (alt-NHEJ) refers to more recently described mechanism(s) that repair DSBs in less-efficient backup reactions. There is great interest in defining alt-NHEJ more precisely, including its regulation relative to c-NHEJ, in light of evidence that alt-NHEJ can execute chromosome rearrangements. Progress toward these goals is reviewed. PMID:23637284
Steam separator latch assembly
Challberg, Roy C.; Kobsa, Irvin R.
1994-01-01
A latch assembly removably joins a steam separator assembly to a support flange disposed at a top end of a tubular shroud in a nuclear reactor pressure vessel. The assembly includes an annular head having a central portion for supporting the steam separator assembly thereon, and an annular head flange extending around a perimeter thereof for supporting the head to the support flange. A plurality of latches are circumferentially spaced apart around the head flange with each latch having a top end, a latch hook at a bottom end thereof, and a pivot support disposed at an intermediate portion therebetween and pivotally joined to the head flange. The latches are pivoted about the pivot supports for selectively engaging and disengaging the latch hooks with the support flange for fixedly joining the head to the shroud or for allowing removal thereof.
Steam separator latch assembly
Challberg, R.C.; Kobsa, I.R.
1994-02-01
A latch assembly removably joins a steam separator assembly to a support flange disposed at a top end of a tubular shroud in a nuclear reactor pressure vessel. The assembly includes an annular head having a central portion for supporting the steam separator assembly thereon, and an annular head flange extending around a perimeter thereof for supporting the head to the support flange. A plurality of latches are circumferentially spaced apart around the head flange with each latch having a top end, a latch hook at a bottom end thereof, and a pivot support disposed at an intermediate portion therebetween and pivotally joined to the head flange. The latches are pivoted about the pivot supports for selectively engaging and disengaging the latch hooks with the support flange for fixedly joining the head to the shroud or for allowing removal thereof. 12 figures.
Rhenium Mechanical Properties and Joining Technology
NASA Technical Reports Server (NTRS)
Reed, Brian D.; Biaglow, James A.
1996-01-01
Iridium-coated rhenium (Ir/Re) provides thermal margin for high performance and long life radiation cooled rockets. Two issues that have arisen in the development of flight Ir/Re engines are the sparsity of rhenium (Re) mechanical property data (particularly at high temperatures) required for engineering design, and the inability to directly electron beam weld Re chambers to C103 nozzle skirts. To address these issues, a Re mechanical property database is being established and techniques for creating Re/C103 transition joints are being investigated. This paper discusses the tensile testing results of powder metallurgy Re samples at temperatures from 1370 to 2090 C. Also discussed is the evaluation of Re/C103 transition pieces joined by both, explosive and diffusion bonding. Finally, the evaluation of full size Re transition pieces, joined by inertia welding, as well as explosive and diffusion bonding, is detailed.
Joining of ceramics of different biofunction by hot isostatic pressing
DOE Office of Scientific and Technical Information (OSTI.GOV)
Li, Jianguo; Harmansson, L.; Soeremark, R.
1993-10-01
Monolithic zirconia (Z) and zirconia-hydroxyapatite (Z/HA) composites were joined by cold isostatic pressing (CIP at 300 MPa) and subsequently by glass-encapsulated hot isostatic pressing (HIP at 1225 C, 1 h and 200 MPa). The physical and mechanical properties of the materials were measured. The fracture surface was studied using a light microscope. The results indicate a strength level of the joint similar to that of the corresponding composite material (Z/HA), 845 and 860 MPa, respectively. Similar experiments with monolithic alumina (A) and alumina-hydroxyapatite (A/HA) were carried out without success. Cracking occurred in the joint area during the cold isostatic pressingmore » process. It seems that ceramics with high green strength and similar green density are essential when joining ceramics by combined CIP and HIP processes.« less
High-temperature brazing for reliable tungsten CFC joints
NASA Astrophysics Data System (ADS)
Koppitz, Th; Pintsuk, G.; Reisgen, U.; Remmel, J.; Hirai, T.; Sievering, R.; Rojas, Y.; Casalegno, V.
2007-03-01
The joining of tungsten and carbon-based materials is demanding due to the incompatibility of their chemical and thermophysical properties. Direct joining is unfeasible by the reason of brittle tungsten carbide formation. High-temperature brazing has been investigated in order to find a suitable brazing filler metal (BFM) which successfully acts as an intermediary between the incompatible properties of the base materials. So far only low Cr-alloyed Cu-based BFMs provide the preferential combination of good wetting action on both materials, tolerable interface reactions, and a precipitation free braze joint. Attempts to implement a higher melting metal (e.g. Pd, Ti, Zr) as a BFM have failed up to now, because the formation of brittle precipitations and pores in the seam were inevitable. But the wide metallurgical complexity of this issue is regarded to offer further joining potential.
Development of Metal Matrix Composites for NASA's Advanced Propulsion Systems
NASA Technical Reports Server (NTRS)
Lee, J.; Elam, S.
2001-01-01
The state-of-the-art development of several Metal Matrix Composites (MMC) for NASA's advanced propulsion systems will be presented. The goal is to provide an overview of NASA-Marshall Space Flight Center's on-going activities in MMC components for advanced liquid rocket engines such as the X-33 vehicle's Aerospike engine and X-34's Fastrac engine. The focus will be on lightweight, low cost, and environmental compatibility with oxygen and hydrogen of key MMC materials, within each of NASA's new propulsion application, that will provide a high payoff for NASA's Reusable Launch Vehicles and space access vehicles. In order to fabricate structures from MMC, effective joining methods must be developed to join MMC to the same or to different monolithic alloys. Therefore, a qualitative assessment of MMC's welding and joining techniques will be outlined.
The Mechanical Behavior of Friction-Stir Spot Welded Aluminum Alloys
NASA Astrophysics Data System (ADS)
Güler, Hande
2014-10-01
Aluminum and alloys are widely used in the automotive industry due to the light weight, good formability, and malleability. Spot welding is the most commonly used joining method of these materials, but the high current requirements and the inconsistent quality of the final welds make this process unsuitable. An alternative welding technique, the friction-stir spot welding process, can also be successfully used in joining of aluminum and alloys. In this study, 1-mm-thick AA5754 Al-alloy plates in the H-111 temper conditions were joined by friction-stir spot welding using two different weld parameters such as tool rotational speed and dwell time. Mechanical properties of the joints were obtained with extensive hardness measurements and tensile shear tests. The effect of these parameters on the failure modes of welded joints was also determined.
Bonding Cu to Al2O3 with Bi-B-Zn Oxide Glass Via Oxidation-Reduction Reaction
NASA Astrophysics Data System (ADS)
Chen, Jianqiang; Li, Yufeng; Miao, Weiliang; Mai, Chengle; Li, Mingyu
2018-01-01
Bonding Cu on Al2O3 is a key and difficult technology applied in high-power semiconductor devices. A method proposed in this work investigates bonding with a kind of Bi-B-Zn oxide glass powder paste as a solder. Oxidation-reduction reactions between the Cu plate and the solder took place and generated Bi metal during the joining procedure. With an increase in the joining temperature, the tensile strength increased due to the increase of Bi metal formation. The Bi metal played an important role in joining Cu and Al2O3 because of its much better wettability on Cu than that of the oxides. A compound ZnAl2O4 was observed to form between the Al2O3 ceramic and oxide layer, which strengthened the bond.
ERIC Educational Resources Information Center
Muthoni, Kamau Joyce
2016-01-01
In Kenya there is still a high population of children either born with or who develop physical challenges. These children are often neglected and most do not join school at the expected age. In joining school they encounter several difficulties in their play and learning activities. These children with physical challenges have developmental needs…
The 1985 Army Experience Survey: Tabular Descriptions of Mid-Career Separatees. Volume 1
1986-01-01
processed through survey receipt control and sample management systems . Data were also keyed, edited, jcoded, and weighted. The coding schemes...270-271 048 R136 REGION OF RESIDENCE WHEN YOU JOINED ARMY---------------------------------------272 273 049 E137...PROB. CHISQUARE APPROX. 41.551 10 0.0000 A -. 0 272 R136 -- REGION OF RESIDENCE WHEN YOU JOINED ARMY RECODED - WHAT STATE WERE YOU LIVING IN WHEN YOU
Viet Cong Recruitment: Why and How Men Join
1967-12-01
have been subordinated to the demands of intensified warfare. Today, more and more youths in their early teens are performing nonmilitary, paramilitary...women, influenced by their noble example, or moved to join the movement to impress the girls of their village.) Though forcible recruitment, including...sisters who died heroically while leading Vietnamese forces in battle against the Chinese. The Viet Cong is skillful in exploiting the appeal of girls
Cosmonaut Aleksey Leonov joins belly dancer on stage at Folklife Festival
NASA Technical Reports Server (NTRS)
1974-01-01
Cosmonaut Aleksey A. Leonov, in one of the lighter moments of activity involving Soviet Cosmonauts and American Astronauts, joins a belly dancer on stage as several visitors to weekend activity at the site of San Antonio's HemisFair look on. Leonov is commander of the Soviet Apollo Soyuz Test Project (ASTP) crew. The Lebanese dancing was just one feature among many during the Texas Folklife Festival.
Amorphous Carbon-Boron Nitride Nanotube Hybrids
NASA Technical Reports Server (NTRS)
Kim, Jae Woo (Inventor); Siochi, Emilie J. (Inventor); Wise, Kristopher E. (Inventor); Lin, Yi (Inventor); Connell, John (Inventor)
2016-01-01
A method for joining or repairing boron nitride nanotubes (BNNTs). In joining BNNTs, the nanotube structure is modified with amorphous carbon deposited by controlled electron beam irradiation to form well bonded hybrid a-C/BNNT structures. In repairing BNNTs, the damaged site of the nanotube structure is modified with amorphous carbon deposited by controlled electron beam irradiation to form well bonded hybrid a-C/BNNT structures at the damage site.
The Intentions of Men 23 to 29 Years Old to Join the Military: Results of a National Survey.
ERIC Educational Resources Information Center
Borack, Jules I.
Since the population of 17-to-21-year-old males, the traditional source for military recruitment, will decline sharply during the 1980s, consideration is being given to recruiting males aged 23-29. A national survey was conducted to assess the interest of 23-to-29-year-old men in joining the military under present conditions and with monetary…
Global knowledge, local implications: a community college's response
NASA Astrophysics Data System (ADS)
Valentin, Marjorie R.; Stroup, Margaret H.; Donnelly, Judith F.
2005-10-01
Three Rivers Community College (TRCC), with federal funding, provided a customized laser program for Joining Technologies in Connecticut, which offers world-class resources for welding and joining applications. This program addresses the shortage of skilled labor in the laser arena, lack of knowledge of fundamental science of applied light, and an increase in nonperforming product. Hiring and retraining a skilled workforce are important and costly issues facing today's small manufacturing companies.
1986-12-02
communist is an existential choice and investment, which does not mean joining the "party" for private gain or mere political sub- sistence in it...have the greatest existential interest in them, whose living conditions are such that they must long for them but only If they join forces with all...Naturally, the role of the intelligentsia, and not only the " humanist intelli- gentsia but all of the. intelligentsia that combines knowledge and
Toward a Persistent Object Base.
1986-07-01
would eliminate the user burden of explicitly invoking a decompressing program before each use of the compresed file. Another kind of flexible...joined to Source .version. It Is not the case, however, that I two relations have attributes with the same types that It always makes sense to join them...25 V V V~ ~ . - .. ~ " - IPE-~w Fam .rf rw vqrf wwp IECURITY CLASSIFICATION OF THIS PAGE REPORT DOCUMENTATION PAGE Is. REPORT SECURITY CLASSIFICATION
Using and joining a franchised private sector provider network in Myanmar.
O'Connell, Kathryn; Hom, Mo; Aung, Tin; Theuss, Marc; Huntington, Dale
2011-01-01
Quality is central to understanding provider motivations to join and remain within a social franchising network. Quality also appears as a key issue from the client's perspective, and may influence why a client chooses to use a franchised provider over another type of provider. The dynamic relationships between providers of social franchising clinics and clients who use these services have not been thoroughly investigated in the context of Myanmar, which has an established social franchising network. This study examines client motivations to use a Sun Quality Health network provider and provider motivations to join and remain in the Sun Quality Health network. Taken together, these two aims provide an opportunity to explore the symbiotic relationship between client satisfaction and provider incentives to increase the utilization of reproductive health care services. Results from a series of focus group discussions with clients of reproductive health services and franchised providers shows that women chose health services provided by franchised private sector general practitioners because of its perceived higher quality, associated with the availability of effective, affordable, drugs. A key finding of the study is associated with providers. Provider focus group discussions indicate that a principle determinate for joining and remaining in the Sun Quality Health Network was serving the poor.
Joining and Integration of Silicon Nitride Ceramics for Aerospace and Energy Systems
NASA Technical Reports Server (NTRS)
Singh, M.; Asthana, R.
2009-01-01
Light-weight, creep-resistant silicon nitride ceramics possess excellent high-temperature strength and are projected to significantly raise engine efficiency and performance when used as turbine components in the next-generation turbo-shaft engines without the extensive cooling that is needed for metallic parts. One key aspect of Si3N4 utilization in such applications is its joining response to diverse materials. In an ongoing research program, the joining and integration of Si3N4 ceramics with metallic, ceramic, and composite materials using braze interlayers with the liquidus temperature in the range 750-1240C is being explored. In this paper, the self-joining behavior of Kyocera Si3N4 and St. Gobain Si3N4 using a ductile Cu-based active braze (Cu-ABA) containing Ti will be presented. Joint microstructure, composition, hardness, and strength as revealed by optical microscopy, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Knoop microhardness test, and offset compression shear test will be presented. Additionally, microstructure, composition, and joint strength of Si3N4/Inconel 625 joints made using Cu-ABA, will be presented. The results will be discussed with reference to the role of chemical reactions, wetting behavior, and residual stresses in joints.
Universal connectors for joining stringers
NASA Technical Reports Server (NTRS)
Harrison, Jr., Ernest (Inventor)
1987-01-01
This invention is a lightweight, universal connector that joins stringers at various angles. The connectors 10 are fabricated from fiber-epoxy resin strips that wrap around stringers 30 and have ends, tabs 16 and 18, which extend in one general direction. The inside surface of the first tab 16 lies on a plane defined by the stringers being joined, and the second tab 18 is separated from the first tab 16 by a distance equal to their thickness. Stringers 30 of different shapes and sizes are joined by alternately bonding the first tab 16 of one connector between the first 16 and second 18 tabs of another connector. Tee-joints are formed by using web elements 41 and 42 which each partially wrap around a stringer 3010 and have tabs 411 and 421 which are offset, and are bonded between tabs 16 and 18 of universal connectors 109 and 1010 bonded to another stringer 309. Sharp corners are trimmed from the tabs so that a gusset area remains between the stringers for support. Acute angle through obtuse angle joints are formed by trimming those edges of the tabs which lie against the stringers. A specific application of the invention is a Walker 60, utilized by handicapped individuals, fabricated from composite materials that is 40% lighter than similar metallic structures.
Anjum, Sohail; Mahboob, Usman
2016-10-01
To determine the perceptions of house officers working in hospitals about joining anaesthesiology as a career. This quantitative, descriptive questionnaire-based study was carried out from September 2014 to February 2015 in 26 teaching hospitals of Lahore, Pakistan, and comprised house officers. Those with at least three months of working experience in anaesthesiology were included. They were approached in their respective departments and a validated self-reporting questionnaire was delivered to them and received back by hand. SPSS 16 was used for data analysis. Of the 73 house officers approached, 53(72.6%) responded; 35(66%) men and 18(33%) women. Overall, 25(47.16%) respondents refused to join anaesthesiology as a career and 27(50.94%) included it in their first three career choices. Moreover, 25(47.16%) cited minimal interaction with patient as a reason for not taking anaesthesia as a career choice; 29(56.6%) of the respondents believed an anaesthetist had no or little role in surgery. Change in attitude about anaesthesiology as a specialty after having an anaesthesia rotation was mentioned by 26(49.05%) respondents. House officers had reservations about joining anaesthesiology as a career. The findings are suggestive of a positive effect of anaesthesiology house job on house officers attitude about the specialty.
Using and Joining a Franchised Private Sector Provider Network in Myanmar
O'Connell, Kathryn; Hom, Mo; Aung, Tin; Theuss, Marc; Huntington, Dale
2011-01-01
Background Quality is central to understanding provider motivations to join and remain within a social franchising network. Quality also appears as a key issue from the client's perspective, and may influence why a client chooses to use a franchised provider over another type of provider. The dynamic relationships between providers of social franchising clinics and clients who use these services have not been thoroughly investigated in the context of Myanmar, which has an established social franchising network. This study examines client motivations to use a Sun Quality Health network provider and provider motivations to join and remain in the Sun Quality Health network. Taken together, these two aims provide an opportunity to explore the symbiotic relationship between client satisfaction and provider incentives to increase the utilization of reproductive health care services. Methods and Findings Results from a series of focus group discussions with clients of reproductive health services and franchised providers shows that women chose health services provided by franchised private sector general practitioners because of its perceived higher quality, associated with the availability of effective, affordable, drugs. A key finding of the study is associated with providers. Provider focus group discussions indicate that a principle determinate for joining and remaining in the Sun Quality Health Network was serving the poor. PMID:22180781
Choice of payment plan in the Medicare capitation demonstration.
Garfinkel, S A; Schlenger, W E; McLeroy, K R; Bryan, F A; York, B J; Dunteman, G H; Friedlob, A S
1986-07-01
This article identifies factors that influence the choice between joining an HMO and remaining with the traditional fee-for-service system among aged Medicare beneficiaries in three communities. Sources of marketing information were found to be strongly and positively related to the decision to join the HMO. Among beneficiaries who had to switch providers to join, persons who had a prior usual source of care and those who were satisfied with the amount of paperwork required to use that source of care were less likely to enroll in the HMO. Persons who did not have to switch providers to join the HMO were more likely to enroll in the prepaid program if they were satisfied with the amount of paperwork involved in using the HMO prior to the demonstration. Differences among the three communities suggest that the barrier to HMO enrollment presented by having a prior source of care who is not affiliated with the HMO may attenuate as the number of competing HMOs in the community increases, making the medical care environment more competitive. In the community with the most HMOs, persons who already had supplemental insurance were less likely to enroll than those who did not. None of the six HMOs studied experienced adverse selection, based on pre-enrollment health status.
Studying the Issues in Laser Joining of Lightweight Materials in a Coach-Peel Joint Configuration
NASA Astrophysics Data System (ADS)
Yang, Guang
In the automotive industry, aluminum alloys have been widely used and partially replaced the conventional steel structures in order to decrease the weight of a car and improve its fuel efficiency. This Thesis focuses on the development of laser joining of light-weight materials, such as aluminum alloys and high-strength galvanized steels. Among different joint types, the coach-peel configuration is of a specific design that requires a heat source capable of heating up a large surface area of the joint. Coach-peel joints applied on the visible exterior of a car require a smooth transition from the weld surface to the panel surface and low surface roughness without any need for post-processing. Although these joints are used as non-load-bearing components, a desirable strength of the weld is also needed. A fusion-brazing process using a dual-beam laser allows the automotive components such as the roof and side member panels to be joined in a coach-peel configuration with a high surface quality as well as an acceptable strength of the weld. To improve the weld surface quality, processing parameters such as laser beam configuration, laser-wire position, and shielding gas parameters were optimized for joining of aluminum alloy to aluminum alloy. Laser power was optimized for dual-beam laser joining of aluminum alloy to galvanized steel at high speed. The feasibility of joining as-received panels with lubricant was also explored. The identification of strain hardening models of aluminum alloys was conducted for the mechanical finite element analysis of the joint. Control of the molten pool solidification through the selection of laser beam configuration is one approach to improve joint quality. Laser joining of aluminum alloy AA 6111-T4 coach peel panels with the addition of AA 4047 filler wire was investigated using three configurations of laser beam: a single beam, dual beams in-line with the weld bead, and dual beams aligned perpendicular to the weld bead (herein referred to as cross-beam). To compare the three joining processes, the transient heat distribution, cooling rates, and solidification rates were analyzed by three-dimensional finite element models using ANSYS. Microstructure evolution, tensile strength, fracture mechanisms, and surface roughness of joints were investigated accordingly. To improve the weld surface quality of aluminum joints, the laser-wire position and the gas parameters were optimized. Visualization of the gas flow by a CCD camera revealed the effects of nozzle shape, flow rate, inclination angle of the gas tube, nozzle position, and gas compositions (argon and helium) on the weld surface quality. The suppression of plasma plume and the effects of oxidation on the molten pool were illustrated in detail. With an optimized set of processing parameters, the weld surface roughness (Ra) of approximately 1 microm can be achieved. The feasibility of fabricating the aluminum alloy panel joint in the as-received condition, i.e., with stamping lubricant, by using the cross-beam laser was investigated. Two commercial mineral oils, Bonderite L-FM MP-404 and Ferrocote 61 MAL HCL, were applied onto clean panels prior to joining in order to simulate the conditions of the production environment. The formation and growth of hydrogen bubbles inside the molten pool, the stability of welding process, and the possible energy absorption capability of the porous weld were explained. Besides joining of similar materials, cross-beam laser was applied to join aluminum alloy 6111 to hot-dip galvanized steel in the coach-peel configuration. The filler material was not only brazed onto the galvanized steel but also partially fusion-welded with the aluminum panel. Through adjusting the laser power to 3.4 kW, a desirable wetting and spreading of filler wire on both panel surfaces could be achieved, and the thickness of intermetallic layer in the middle section of the interface between the weld bead and steel was less than 2 microm. To better understand the solid/liquid interfacial reaction at the brazing interface, two rotary Gaussian heat source models were introduced to simulate the temperature distribution in the molten pool by using the finite element method. Joint properties were examined in terms of microstructure and mechanical properties. Simulation of the mechanical response of a coach-peel joint is instructive for improvement of the joining process. The effective true stress-strain curve of fusion-brazed AA 4047 was difficult to obtain experimentally. Therefore, the von Mises isotropic flow function of the weld bead was inversely derived by image-based finite element analysis. Through iterative correction, the predicted tensile response of the coach-peel joint matched well with the experiment. The von Mises fracture stresses at the fusion zone boundary and the brazing interface were identified, respectively.
Modelling the strength of an aluminium-steel nailed joint
NASA Astrophysics Data System (ADS)
Goldspiegel, Fabien; Mocellin, Katia; Michel, Philippe
2018-05-01
For multi-material applications in automotive industry, a cast aluminium (upper layer) and dual-phase steel (lower layer) superposition joined with High-Speed Nailing process is investigated through an experimental vs numerical framework. Using FORGE® finite-element software, results from joining simulations have been inserted into models in charge of nailed-joint mechanical testings. Numerical Shear and Cross-tensile tests are compared to experimental ones to discuss discrepancy and possible improvements.
NASA Technical Reports Server (NTRS)
1984-01-01
A low cost, low power, self-contained portable welding gun designed for joining thermoplastics which become soft when heated and harden when cooled was developed originally by NASA's Langley Research Center for repairing helicopter windshields. Welder has a broad range of applications for joining both thermoplastic materials in the aerospace, automotive, appliance, and construction industries. Welders portability and low power requirement allow its use on-site in any type of climate, with power supplied by a variety of portable sources.
2013-12-13
Mansur family, a long time Haqqani Network ally joined the Taliban. At this Point, Haji Din Muhammad, a long time associate of Jalaluddin Haqqani wrote...activists on the move to the Hijazi area of Saudi Arabia. The migrants were a well educated bunch in need of employment. At the same time, Saudi...1995, the Mansur family, a long time Haqqani Network ally joined the Taliban. At this Point, Haji Din Muhammad, a long time associate of Jalaluddin
Conflicts of Shared Resources: A Case Study of River Nile
2012-03-22
as Lake Kivu. Rwanda joined the earlier Nile basin project, Hydromet , in 1967, with the support on the UNDP. 18 Although the country does not...operation Hydromet . In 1967, with the assistance of the United Nations Development Program (UNDP) and the World Meteorological Organization (WMO), Egypt...Kenya, Sudan, Tanzania and Uganda launched the Hydromet Survey project to regulate the water level of the Nile.”30 Rwanda joined later while Ethiopia
Slow Joining of Newly Replicated DNA Chains in DNA Polymerase I-Deficient Escherichia coli Mutants*
Okazaki, Reiji; Arisawa, Mikio; Sugino, Akio
1971-01-01
In Escherichia coli mutants deficient in DNA polymerase I, newly replicated short DNA is joined at about 10% of the rate in the wild-type strains. It is postulated that DNA polymerase I normally functions in filling gaps between the nascent short segments synthesized by the replication complex. Possible implications of the finding are discussed in relation to other abnormal properties of these mutants. PMID:4943548
Welding technologies as applied to nuclear manufacturing
NASA Astrophysics Data System (ADS)
Roper, J. R.
1992-10-01
This is the trip report of John R. Roper, who traveled to England 25 Sep. through 8 Oct. 1992. Dr. Roper attended the US/UK JOWOG 22-D Joining Technical Exchange meeting and gave a presentation on Welding Finite Element Analysis and the Precision Joining Center at the Atomic Weapons Establishment in Aldermaston, United Kingdom. Dr. Roper also toured the Welding Institute in Abington, UK and discussed technology exchange of weld thermal and mechanical material responses.
Henager, Jr., Charles W [Kennewick, WA; Brimhall, John L [West Richland, WA
2001-08-21
According to the present invention, a joined product is at least two ceramic parts, specifically bi-element carbide parts with a bond joint therebetween, wherein the bond joint has a metal silicon phase. The bi-element carbide refers to compounds of MC, M.sub.2 C, M.sub.4 C and combinations thereof, where M is a first element and C is carbon. The metal silicon phase may be a metal silicon carbide ternary phase, or a metal silicide.
ERIC Educational Resources Information Center
New York City Bicentennial Corp., NY.
Exploits of 20 black men, slave and free, who fought in battles of the American Revolution in New York state are recounted. At the beginning of the Revolutionary War, colonies did not allow slaves or free blacks to join the Continental Army. Only after the British Army offered freedom to slaves who joined the royal ranks did the Continental Army…
Gaussian Random Fields Methods for Fork-Join Network with Synchronization Constraints
2014-12-22
substantial efforts were dedicated to the study of the max-plus recursions [21, 3, 12]. More recently, Atar et al. [2] have studied a fork-join...feedback and NES, Atar et al. [2] show that a dynamic priority discipline achieves throughput optimal- ity asymptotically in the conventional heavy...2011) Patient flow in hospitals: a data-based queueing-science perspective. Submitted to Stochastic Systems, 20. [2] R. Atar , A. Mandelbaum and A
A Combined Experimental and Numerical Approach to the Laser Joining of Hybrid Polymer - Metal Parts
NASA Astrophysics Data System (ADS)
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.
FRICTION STIR LAP WELDING OF ALUMINUM - POLYMER USING SCRIBE TECHNOLOGY
DOE Office of Scientific and Technical Information (OSTI.GOV)
Upadhyay, Piyush; Hovanski, Yuri; Fifield, Leonard S.
2015-02-16
Friction Stir Scribe (FSS) technology is a relatively new variant of Friction Stir Welding (FSW) which enables lap joining of dissimilar material with very different melting points and different high temperature flow behaviors. The cutter scribe attached at the tip of FSW tool pin effectively cuts the high melting point material such that a mechanically interlocking feature is created between the dissimilar materials. The geometric shape of this interlocking feature determines the shear strength attained by the lap joint. This work presents first use of scribe technology in joining polymers to aluminum alloy. Details of the several runs of scribemore » welding performed in lap joining of ~3.175mm thick polymers including HDPE, filled and unfilled Nylon 66 to 2mm thick AA5182 are presented. The effect of scribe geometry and length on weld interlocking features is presented along with lap shear strength evaluations.« less
Characterization of Nitinol Laser-Weld Joints by Nondestructive Testing
NASA Astrophysics Data System (ADS)
Wohlschlögel, Markus; Gläßel, Gunter; Sanchez, Daniela; Schüßler, Andreas; Dillenz, Alexander; Saal, David; Mayr, Peter
2015-12-01
Joining technology is an integral part of today's Nitinol medical device manufacturing. Besides crimping and riveting, laser welding is often applied to join components made from Nitinol to Nitinol, as well as Nitinol components to dissimilar materials. Other Nitinol joining techniques include adhesive bonding, soldering, and brazing. Typically, the performance of joints is assessed by destructive mechanical testing, on a process validation base. In this study, a nondestructive testing method—photothermal radiometry—is applied to characterize small Nitinol laser-weld joints used to connect two wire ends via a sleeve. Two different wire diameters are investigated. Effective joint connection cross sections are visualized using metallography techniques. Results of the nondestructive testing are correlated to data from destructive torsion testing, where the maximum torque at fracture is evaluated for the same joints and criteria for the differentiation of good and poor laser-welding quality by nondestructive testing are established.
Microwave facilities for welding thermoplastic composites and preliminary results.
Ku, H S; Siores, E; Ball, J A
1999-01-01
The wide range of applications of microwave technology in manufacturing industries has been well documented (NRC, 1994; Thuery, 1992). In this paper, a new way of joining fibre reinforced thermoplastic composites with or without primers is presented. The microwave facility used is also discussed. The effect of power input and cycle time on the heat affected zone (HAZ) is detailed together with the underlying principles of test piece material interactions with the electromagnetic field. The process of autogenous joining of 33% by weight of random glass fibre reinforced Nylon 66, polystyrene (PS) and low density polyethylene (LDPE) as well as 23.3% by weight of carbon fibre reinforced PS thermoplastic composites is discussed together with developments using filler materials, or primers in the heterogenous joining mode. The weldability dependence on the dielectric loss tangent of these materials at elevated temperatures is also described.
Joining and Integration of Silicon Carbide for Turbine Engine Applications
NASA Technical Reports Server (NTRS)
Halbig, Michael C.; Singh, Mrityunjay; Coddington, Bryan; Asthana, Rajiv
2010-01-01
The critical need for ceramic joining and integration technologies is becoming better appreciated as the maturity level increases for turbine engine components fabricated from ceramic and ceramic matrix composite materials. Ceramic components offer higher operating temperatures and reduced cooling requirements. This translates into higher efficiencies and lower emissions. For fabricating complex shapes, diffusion bonding of silicon carbide (SiC) to SiC is being developed. For the integration of ceramic parts to the surrounding metallic engine system, brazing of SiC to metals is being developed. Overcoming the chemical, thermal, and mechanical incompatibilities between dissimilar materials is very challenging. This presentation will discuss the types of ceramic components being developed by researchers and industry and the benefits of using ceramic components. Also, the development of strong, crack-free, stable bonds will be discussed. The challenges and progress in developing joining and integration approaches for a specific application, i.e. a SiC injector, will be presented.
Contamination detection NDE for cleaning process inspection
NASA Technical Reports Server (NTRS)
Marinelli, W. J.; Dicristina, V.; Sonnenfroh, D.; Blair, D.
1995-01-01
In the joining of multilayer materials, and in welding, the cleanliness of the joining surface may play a large role in the quality of the resulting bond. No non-intrusive techniques are currently available for the rapid measurement of contamination on large or irregularly shaped structures prior to the joining process. An innovative technique for the measurement of contaminant levels in these structures using laser based imaging is presented. The approach uses an ultraviolet excimer laser to illuminate large and/or irregular surface areas. The UV light induces fluorescence and is scattered from the contaminants. The illuminated area is viewed by an image-intensified CCD (charge coupled device) camera interfaced to a PC-based computer. The camera measures the fluorescence and/or scattering from the contaminants for comparison with established standards. Single shot measurements of contamination levels are possible. Hence, the technique may be used for on-line NDE testing during manufacturing processes.
DOE Office of Scientific and Technical Information (OSTI.GOV)
O'Brien, M.H.; Coon, D.M.
Time-dependent failure at elevated temperatures currently governs the service life of oxynitride glass-joined silicon nitride. Creep, devitrification, stress- aided oxidation-controlled slow crack growth, and viscous cabitation-controlled failure are examined as possible controlling mechanisms. Creep deformation failure is observed above 1000{degrees}C. Fractographic evidence indicates cavity formation and growth below 1000{degrees}C. Auger electron spectroscopy verified that the oxidation rate of the joining glass is governed by the oxygen supply rate. Time-to-failure data and those predicted using the Tsai and Raj, and Raj and Dang viscous cavitation models. It is concluded that viscous relaxation and isolated cavity growth control the rate of failuremore » in oxynitride glass-filled silicon nitride joints below 1000{degrees}C. Several possible methods are also proposed for increasing the service lives of these joints.« less
NASA Technical Reports Server (NTRS)
Singh, M.; Asthana, R.
2008-01-01
Recent research and development activities in joining and integration of carbon-carbon (C/C) composites to metals such as Ti and Cu-clad-Mo for thermal management applications are presented with focus on advanced brazing techniques. A wide variety of carbon-carbon composites with CVI and resin-derived matrices were joined to Ti and Cu-clad Mo using a number of active braze alloys. The brazed joints revealed good interfacial bonding, preferential precipitation of active elements (e.g., Ti) at the composite/braze interface. Extensive braze penetration of the inter-fiber channels in the CVI C/C composites was observed. The chemical and thermomechanical compatibility between C/C and metals at elevated temperatures is assessed. The role of residual stresses and thermal conduction in brazed C/C joints is discussed. Theoretical predictions of the effective thermal resistance suggest that composite-to-metal brazed joints may be promising for lightweight thermal management applications.
NASA Technical Reports Server (NTRS)
Hajela, P.; Chen, J. L.
1986-01-01
The present paper describes an approach for the optimum sizing of single and joined wing structures that is based on representing the built-up finite element model of the structure by an equivalent beam model. The low order beam model is computationally more efficient in an environment that requires repetitive analysis of several trial designs. The design procedure is implemented in a computer program that requires geometry and loading data typically available from an aerodynamic synthesis program, to create the finite element model of the lifting surface and an equivalent beam model. A fully stressed design procedure is used to obtain rapid estimates of the optimum structural weight for the beam model for a given geometry, and a qualitative description of the material distribution over the wing structure. The synthesis procedure is demonstrated for representative single wing and joined wing structures.
Performing a local barrier operation
Archer, Charles J; Blocksome, Michael A; Ratterman, Joseph D; Smith, Brian E
2014-03-04
Performing a local barrier operation with parallel tasks executing on a compute node including, for each task: retrieving a present value of a counter; calculating, in dependence upon the present value of the counter and a total number of tasks performing the local barrier operation, a base value, the base value representing the counter's value prior to any task joining the local barrier; calculating, in dependence upon the base value and the total number of tasks performing the local barrier operation, a target value of the counter, the target value representing the counter's value when all tasks have joined the local barrier; joining the local barrier, including atomically incrementing the value of the counter; and repetitively, until the present value of the counter is no less than the target value of the counter: retrieving the present value of the counter and determining whether the present value equals the target value.
Performing a local barrier operation
Archer, Charles J; Blocksome, Michael A; Ratterman, Joseph D; Smith, Brian E
2014-03-04
Performing a local barrier operation with parallel tasks executing on a compute node including, for each task: retrieving a present value of a counter; calculating, in dependence upon the present value of the counter and a total number of tasks performing the local barrier operation, a base value of the counter, the base value representing the counter's value prior to any task joining the local barrier; calculating, in dependence upon the base value and the total number of tasks performing the local barrier operation, a target value, the target value representing the counter's value when all tasks have joined the local barrier; joining the local barrier, including atomically incrementing the value of the counter; and repetitively, until the present value of the counter is no less than the target value of the counter: retrieving the present value of the counter and determining whether the present value equals the target value.
Fast half-sibling population reconstruction: theory and algorithms.
Dexter, Daniel; Brown, Daniel G
2013-07-12
Kinship inference is the task of identifying genealogically related individuals. Kinship information is important for determining mating structures, notably in endangered populations. Although many solutions exist for reconstructing full sibling relationships, few exist for half-siblings. We consider the problem of determining whether a proposed half-sibling population reconstruction is valid under Mendelian inheritance assumptions. We show that this problem is NP-complete and provide a 0/1 integer program that identifies the minimum number of individuals that must be removed from a population in order for the reconstruction to become valid. We also present SibJoin, a heuristic-based clustering approach based on Mendelian genetics, which is strikingly fast. The software is available at http://github.com/ddexter/SibJoin.git+. Our SibJoin algorithm is reasonably accurate and thousands of times faster than existing algorithms. The heuristic is used to infer a half-sibling structure for a population which was, until recently, too large to evaluate.
Electron Beam Brazing of Titanium for Construction in Space
NASA Technical Reports Server (NTRS)
Flom, Yury
2006-01-01
An extended presence of humans in space requires an in-situ capability to construct various permanent structures to support scientific research, power generation, communication, radiation shielding and other functions. Electron Beam (EB) vacuum brazing has been identified as one of the best joining processes for in-space joining, particular for making a large quantity of permanent joints as required for construction of the sizeable truss structures. Thin wall titanium tubes are perhaps the best choice because of their high stiffness, excellent strength-to-weight ratio and great metal forming and joining ability. An innovative EB vacuum spot brazing process is being developed at Goddard Space Flight Center to be used for robotic as well as human-assisted construction in space. This paper describes experimental results obtained during the initial effort of EB brazing of titanium tubes with the special emphasis on low temperature aluminum filler metals.
Applying NASA's explosive seam welding
NASA Technical Reports Server (NTRS)
Bement, Laurence J.
1991-01-01
The status of an explosive seam welding process, which was developed and evaluated for a wide range of metal joining opportunities, is summarized. The process employs very small quantities of explosive in a ribbon configuration to accelerate a long-length, narrow area of sheet stock into a high-velocity, angular impact against a second sheet. At impact, the oxide films of both surface are broken up and ejected by the closing angle to allow atoms to bond through the sharing of valence electrons. This cold-working process produces joints having parent metal properties, allowing a variety of joints to be fabricated that achieve full strength of the metals employed. Successful joining was accomplished in all aluminum alloys, a wide variety of iron and steel alloys, copper, brass, titanium, tantalum, zirconium, niobium, telerium, and columbium. Safety issues were addressed and are as manageable as many currently accepted joining processes.
Glass-ceramic joint and method of joining
Meinhardt, Kerry D [Richland, WA; Vienna, John D [West Richland, WA; Armstrong, Timothy R [Clinton, TN; Pederson, Larry R [Kennewick, WA
2003-03-18
The present invention is a glass-ceramic material and method of making useful for joining a solid ceramic component and at least one other solid component. The material is a blend of M1-M2-M3, wherein M1 is BaO, SrO, CaO, MgO, or combinations thereof, M2 is Al.sub.2 O.sub.3, present in the blend in an amount from 2 to 15 mol %, M3 is SiO.sub.2 with up to 50 mol % B.sub.2 O.sub.3 that substantially matches a coefficient of thermal expansion of the solid electrolyte. According to the present invention, a series of glass ceramics in the M1-Al.sub.2 O.sub.3 -M3 system can be used to join or seal both tubular and planar solid oxide fuel cells, oxygen electrolyzers, and membrane reactors for the production of syngas, commodity chemicals and other products.
Applications of Materials Selection For Joining Composite/Alloy Piping Systems
NASA Technical Reports Server (NTRS)
Crosby, Karen E.; Smith, Brett H.; Mensah, Patrick F.; Stubblefield, Michael A.
2001-01-01
A study in collaboration between investigators at Southern University and Louisiana State University in Baton Rouge, Louisiana and NASA/MSFC is examining materials for modeling and analysis of heat-activated thermal coupling for joining composite to composite/alloy structures. The short-term objectives of this research are to develop a method for joining composite or alloy structures, as well as to study the effects of thermal stress on composite-to-alloy joints. This investigation will result in the selection of a suitable metallic alloy. Al-Li alloys have potential for this purpose in aerospace applications due to their excellent strength-to-weight ratio. The study of Al-Li and other alloys is of significant importance to this and other aerospace as well as offshore related interests. Further research will incorporate the use of computer aided design and rapid prototype hardware for conceptual design and verification of a potential composite piping delivery system.
Joining of Silicon Carbide: Diffusion Bond Optimization and Characterization
NASA Technical Reports Server (NTRS)
Halbig, Michael C.; Singh, Mrityunjay
2008-01-01
Joining and integration methods are critically needed as enabling technologies for the full utilization of advanced ceramic components in aerospace and aeronautics applications. One such application is a lean direct injector for a turbine engine to achieve low NOx emissions. In the application, several SiC substrates with different hole patterns to form fuel and combustion air channels are bonded to form the injector. Diffusion bonding is a joining approach that offers uniform bonds with high temperature capability, chemical stability, and high strength. Diffusion bonding was investigated with the aid of titanium foils and coatings as the interlayer between SiC substrates to aid bonding. The influence of such variables as interlayer type, interlayer thickness, substrate finish, and processing time were investigated. Optical microscopy, scanning electron microscopy, and electron microprobe analysis were used to characterize the bonds and to identify the reaction formed phases.
The Use of Explosive Forming for Fastening and Joining Structural and Pressure Components
NASA Technical Reports Server (NTRS)
Schroeder, J. W.
1985-01-01
Explosive expansion of tubes into tubesheets has been used for over 20 years in the fabrication and repair of shell and tube heat exchangers. The use of explosives to perform these expansions has offered several distinct advantages over other methods. First, the process is fast and economical and can be performed with minimal training of personnel. Secondly, explosive forming does not cause the deleterious metallurgical effects which often result from other forming operations. In addition, the process can be performed remotely without the need for sophisticated handling equipment. The expansion of tubes into tubesheets is only one of many possible fastening and joining applications for which explosive forming can be used to achieve highly successful results. The explosive forming process and where it has been used are described. In addition, some possible adaptations to other joining applications are identified and discussed.
Mental illness stigma and disclosure in college students.
Corrigan, Patrick W; Kosyluk, Kristin A; Markowitz, Fred; Brown, Robyn Lewis; Conlon, Bridget; Rees, Jo; Rosenberg, Jessica; Ellefson, Sarah; Al-Khouja, Maya
2016-06-01
The aim of this study was to investigate the relationship between mental illness identity, shame, secrecy, public stigma, and disclosure amongst college students. Participants included 1393 college students from five postsecondary institutions. Structural equation modeling was used to examine two path models predicting disclosure and desire to join a program aiding with disclosure. Variables found to be significant in predicting disclosure included mental illness identity and public stigma. In turn, desire for disclosure predicted desire to join a program aiding in disclosure. Gender and race/ethnic differences were observed, with men and Whites more likely to want to disclose a mental illness or join a program aiding with disclosure compared with women and non-Whites, respectively. These findings suggest that some college students may find programs aiding in disclosure useful in assisting them to achieve their desire to be "out" with their mental illness.
Dissimilar material joining using laser (aluminum to steel using zinc-based filler wire)
NASA Astrophysics Data System (ADS)
Mathieu, Alexandre; Shabadi, Rajashekar; Deschamps, Alexis; Suery, Michel; Matteï, Simone; Grevey, Dominique; Cicala, Eugen
2007-04-01
Joining steel with aluminum involving the fusion of one or both materials is possible by laser beam welding technique. This paper describes a method, called laser braze welding, which is a suitable process to realize this structure. The main problem with thermal joining of steel/aluminum assembly with processes such as TIG or MIG is the formation of fragile intermetallic phases, which are detrimental to the mechanical performances of such joints. Braze welding permits a localized fusion of the materials resulting in a limitation on the growth of fragile phases. This article presents the results of a statistical approach for an overlap assembly configuration using a filler wire composed of 85% Zn and 15% Al. Tensile tests carried on these assemblies demonstrate a good performance of the joints. The fracture mechanisms of the joints are analyzed by a detailed characterization of the seams.
NASA Astrophysics Data System (ADS)
Kaloyanova, Valentina B.
Recent research trends have indicated an interest in High-Altitude, Long-Endurance (HALE) aircraft as a low-cost alternative to certain space missions, such as telecommunication relay, environmental sensing and military reconnaissance. HALE missions require a light vehicle flying at low speed in the stratosphere at altitudes of 60,000-80,000 ft, with a continuous loiter time of up to several days. To provide high lift and low drag at these high altitudes, where the air density is low, the wing area should be increased, i.e., high-aspect-ratio wings are necessary. Due to its large span and lightweight, the wing structure is very flexible. To reduce the structural deformation, and increase the total lift in a long-spanned wing, a sensorcraft model with a joined-wing configuration, proposed by AFRL, is employed. The joined-wing encompasses a forward wing, which is swept back with a positive dihedral angle, and connected with an aft wing, which is swept forward. The joined-wing design combines structural strength, high aerodynamic performance and efficiency. As a first step to study the joined-wing structural behavior an 1-D approximation model is developed. The 1-D approximation is a simple structural model created using ANSYS BEAM4 elements to present a possible approach for the aerodynamics-structure coupling. The pressure loads from the aerodynamic analysis are integrated numerically to obtain the resultant aerodynamic forces and moments (spanwise lift and pitching moment distributions, acting at the aerodynamic center). These are applied on the 1-D structural model. A linear static analysis is performed under this equivalent load, and the deformed shape of the 1-D model is used to obtain the deformed shape of the actual 3-D joined wing, i.e. deformed aerodynamic surface grid. To date in the existing studies, only simplified structural models have been examined. In the present work, in addition to the simple 1-D beam model, a semi-monocoque structural model is developed. All stringers, skin panels, ribs and spars are represented by appropriate elements in a finite-element model. Also, the model accounts for the fuel weight and sensorcraft antennae housed within the wings. Linear and nonlinear static analyses under the aerodynamic load are performed. The stress distribution in the wing as well as deformation is explored. Starting with a structural model with uniform mass distribution, a design optimization is performed to achieve a fully stressed design. As the joined-wing structure is prone to buckling, after the design optimization is complete linear and nonlinear bucking analyses are performed to study the global joined-wing structural instability, the load magnitude at which it is expected to occur, and the buckling mode. The buckled shape of the aft wing (which is subjected to compression) is found to resemble that of a fixed-pinned column. The linear buckling analysis overestimates the buckling load. However, even the nonlinear buckling analysis results in a load factor higher than 3, i.e. the wing structure is buckling safe under its current loading conditions. As the region of the joint has a very complicated geometry that has adverse effects in the flow and stress behavior an independent, more finely meshed model (submodel) of the joint region is generated and analyzed. A detailed discussion of the stress distribution obtained in the joint region via the submodeling technique is presented in this study as well. It is found out that compared to its structural response, the joint adverse effects are much more pronounced in its aerodynamic response, so it is suggested for future studies the geometry of the joint to be optimized based on its aerodynamic performance. As this design and analysis study is aimed towards developing a realistic structural representation of the innovative joined-wing configuration, in addition to the "global", or upper-level optimization, a local level design optimization is performed as well. At the lower (local) level detailed models of wing structural panels are used to compute more complex failure modes and to design the details that are not included in the upper (global) level model. Proper coordination between local skin-stringer panel models and the global joined-wing model prevents inconsistency between the upper- (global) and lower- (local) level design models. (Abstract shortened by UMI.)
Advances in Solid State Joining of Haynes 230 High Temperature Alloy
NASA Technical Reports Server (NTRS)
Ding, R. Jeffrey; Schneider, Judy; Walker, Bryant
2010-01-01
The J-2X engine is being designed for NASA s new class of crew and launch vehicles, the Ares I and Ares V. The J-2X is a LOX/Hydrogen upper stage engine with 294,000 lbs of thrust and a minimum Isp of 448 seconds. As part of the design criteria to meet the performance requirements a large film-cooled nozzle extension is being designed to further expand the hot gases and increases the specific impulse. The nozzle extension is designed using Haynes 230, a nickel-chromium-tungsten-molybdenum superalloy. The alloy was selected for its high strength at elevated temperatures and resistance to hydrogen embrittlement. The nozzle extension is manufactured from Haynes 230 plate spun-forged to form the contour and chemically-milled pockets for weight reduction. Currently fusion welding is being evaluated for joining the panels which are then mechanically etched and thinned to required dimensions for the nozzle extension blank. This blank is then spun formed into the parabolic geometry required for the nozzle. After forming the nozzle extension, weight reduction pockets are chemically milled into the nozzle. Fusion welding of Haynes results in columnar grains which are prone to hot cracking during forming processes. This restricts the ability to use spin forging to produce the nozzle contour. Solid state joining processes are being pursued as an alternative process to produce a structure more amenable to spin forming. Solid state processes have been shown to produce a refined grain structure within the joint regions as illustrated in Figure 1. Solid state joining processes include friction stir welding (FSW) and a patented modification termed thermal stir welding (TSW). The configuration of TSWing utilizes an induction coil to preheat the material minimizing the burden on the weld tool extending its life. This provides the ability to precisely select and control the temperature. The work presented in this presentation investigates the feasibility of joining the Haynes 230 alloy using the solid state welding processes of FSW and TSW. Process descriptions and attributes of each weld process will be presented. Weld process set-up and welding techniques will be discussed leading to the challenges experienced in joining the superalloy. Mechanical property data will also be presented.
Corrugated outer sheath gas-insulated transmission line
Kemeny, George A.; Cookson, Alan H.
1981-01-01
A gas-insulated transmission line includes two transmission line sections each of which are formed of a corrugated outer housing enclosing an inner high-voltage conductor disposed therein, with insulating support means supporting the inner conductor within the outer housing and an insulating gas providing electrical insulation therebetween. The outer housings in each section have smooth end sections at the longitudinal ends thereof which are joined together by joining means which provide for a sealing fixed joint.
ERIC Educational Resources Information Center
Chan, Sophia S. C.; Wong, David C. N.; Cheung, Yee Tak Derek; Leung, Doris Y. P.; Lau, Lisa; Lai, Vienna; Lam, Tai-Hing
2015-01-01
The present trial examined the effectiveness of brief interventions for smokers who joined the Hong Kong Quit to Win Contest to quit smoking. A block randomized controlled trial allocated 1003 adult daily smokers to three groups: (i) The TEL group (n = 338) received a 5-min nurse-led telephone counselling; (ii) The SMS group (n = 335) received…
The 1985 Army Experience Survey: Tabular Descriptions of First-Term Separatees. Volume 2
1986-01-01
through survey receipt control and sample management systems . Data were also keyed, edited, coded, and weighted. The coding schemes developed to...270-271 048 R136 REGION OF RESIDENCE WHEN YOU JOINED ARMY ...... .................. ... 272-273 049 E137 # TERMS OF ACTIVE ENLISTMENT...STATISTIC VALUE D.F. PROB. CHISQUARE APPROX. 7.830 5 0.1658 e. U 272 R136 -- REGION OF RIESIDENCE WHEN YOU JOINED ARMY RECODED - WHAT STATE WERE YOU LIVING
The 1985 Army Experience Survey: Tabular Descriptions of First-Term Separatees. Volume 1
1986-01-01
Assistance. Survey data were processed through survey receipt control and sample management systems . Data were also keyed, edited, coded, and weighted. The...268-269 047A R135 AGE OF OLDEST CHILD. ..................... .. ..... 270-271 048 R136 REGION OF RESIDENCE WHEN YOU JOINED ARMY...100.0 STATISTIC VALUE D.F. PROD. CHISQUARE APPROX. 65.725 10 0.0000 272 R136 -- REGION OF RESIDENCE WHEN YOU JOINED ARMY RECODED - WHAT STATE WERE
The 1985 Army Experience Survey: Tabular Descriptions of Mid-Career Separatees. Volume 2
1986-01-01
Survey data were processed through survey receipt control and sample management systems . Data were also keyed, edited, coded, and weighted. The coding...270-271 048 R136 REGION OF RESIDENCE WHEN YOU JOINED ARMY ................. . 272-273 049 E137 # TERMS OF ACTIVE ENLISTMENT...STATISTIC VALUE D.F. PROB. CHISQUARE APPROX. 4.449 5 0.4868 I 272 R136 -- REGION OF RESIDENCE WHEN YOU JOINED ARMY RECODED - WHAT STATE WERE YOU LIVING IN
Photographic and photometric enhancement of Lunar Orbiter products, projects A, B and C
NASA Technical Reports Server (NTRS)
1972-01-01
A detailed discussion is presented of the framelet joining, photometric data improvement, and statistical error analysis. The Lunar Orbiter film handling system, readout system, and the digitization are described, along with the technique of joining adjacent framelets by a using a digital computer. Time and cost estimates are given. The problems and techniques involved in improving the digitized data are discussed. It was found that spectacular improvements are possible. Program documentations are included.
Electron Beam Welding to Join Gamma Titanium Aluminide Articles
NASA Technical Reports Server (NTRS)
Kelly, Thomas Joseph (Inventor)
2008-01-01
A method is provided for welding two gamma titanium aluminide articles together. The method includes preheating the two articles to a welding temperature of from about 1700 F to about 2100 F, thereafter electron beam welding the two articles together at the welding temperature and in a welding vacuum to form a welded structure, and thereafter annealing the welded structure at an annealing temperature of from about 1800 F to about 2200 F, to form a joined structure.
CTC Sentinel. Volume 8, Issue 8. August 2015
2015-08-01
of the “inner-city” gang phenomenon. Young Muslim men with a history of social and criminal delinquency are joining up with the Islamic State as...from society manifested itself through petty crime and delinquency . Many are essentially part of street gangs. What the Islamic State brought in...history of delinquency joining up with al-Qa`ida in the tribal areas of Pakistan in the late 2000s. But it has now become a much bigger phenomenon
NASA Technical Reports Server (NTRS)
1991-01-01
Induction heating technology, a magnetic non-deforming process, was developed by Langley researchers to join plastic and composite components in space. Under NASA license, Inductron Corporation uses the process to produce induction heating systems and equipment for numerous applications. The Torobonder, a portable system, comes with a number of interchangeable heads for aircraft repair. Other developments are the E Heating Head, the Toroid Joining Gun, and the Torobrazer. These products perform bonding applications more quickly, safely and efficiently than previous methods.
2017-11-01
NASA officials were joined by Louisiana Gov. John Bel Edwards and New Orleans Mayor Mitch Landrieu, who toured the Michoud Assembly Facility in New Orleans and got a first-hand look at NASA’s new deep space vehicles being built at the facility.
1993-04-14
Scaling (Technology)-Congresses. 3. Joints (Engineering)-Congresses, 4. Metals-Congresses. 5. Composite naterials-Congresses. 6. Ceramic niaterials... COMPOSITE 103 Hsin-Fu Wang, John C, Nelson, Chlen-Li Lin, William W. Gerberich, Charles 1. Skowronek, and Herve E, Deve STRESS-CORROSION CRACKING AT...Arunajatesan, A,H, Carim, TYY Yiin, and VK, Varadan HIGH SPEED JOINING OF ALUMINUM METAL MATRIX COMPOSITES !1SING CONTINUOUS WAVE AND PULSED LASERS
Group Centric Information Sharing Using Hierarchical Models
2011-01-01
enable people to create data using RDF, build vocabularies using web ontology language (OWL), write rules and query data stores using SPARQL [8...a strict joined and the document was added with a strict add. In order to represent the fact that an action is allowed (or not), we have created a...greatly improve the system’s readiness to handle any number of access decision queries . a. The pair is tested against the gSIS Join and Add semantics
NASA Technical Reports Server (NTRS)
Buckley, J. D.; Fox, R. L.; Swain, R. J.
1980-01-01
Low-cost, self-contained, portable welder joins plastic parts by induction heating. Welder is useable in any atmosphere or in vacuum and with most types of thermoplastic; plastic components can be joined in situ. Device is applicable to aerospace industry and in automobile, furniture, and construction industries. Power requirements are easily met by battery or solar energy. In welder, toroidal inductor transfers magnetic flux through thermoplastic to screen. Heated screen causes plastic surface on either side to melt and flow into it to form joint.
Joining of materials using laser heating
Cockeram, Brian V.; Hicks, Trevor G.; Schmid, Glenn C.
2003-07-01
A method for diffusion bonding ceramic layers such as boron carbide, zirconium carbide, or silicon carbide uses a defocused laser beam to heat and to join ceramics with the use of a thin metal foil insert. The metal foil preferably is rhenium, molybdenum or titanium. The rapid, intense heating of the ceramic/metal/ceramic sandwiches using the defocused laser beam results in diffusive conversion of the refractory metal foil into the ceramic and in turn creates a strong bond therein.
NASA Technical Reports Server (NTRS)
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.
NASA Technical Reports Server (NTRS)
Vanaken, Johannes M.
1991-01-01
The feasibility of using active controls to delay the onset of whirl-flutter on a joined-wing tilt rotor aircraft was investigated. The CAMRAD/JA code was used to obtain a set of linear differential equations which describe the motion of the joined-wing tilt-rotor aircraft. The hub motions due to wing/body motion is a standard input to CAMRAD/JA and were obtained from a structural dynamics model of a representative joined-wing tilt-rotor aircraft. The CAMRAD/JA output, consisting of the open-loop system matrices, and the airframe free vibration motion were input to a separate program which performed the closed-loop, active control calculations. An eigenvalue analysis was performed to determine the flutter stability of both open- and closed-loop systems. Sensor models, based upon the feedback of pure state variables and based upon hub-mounted sensors, providing physically measurable accelerations, were evaluated. It was shown that the onset of tilt-rotor whirl-flutter could be delayed from 240 to above 270 knots by feeding back vertical and span-wise accelerations, measured at the rotor hub, to the longitudinal cyclic pitch. Time response calculations at a 270-knot cruise condition showed an active cyclic pitch control level of 0.009 deg, which equates to a very acceptable 9 pound active-control force applied at the rotor hub.
NASA Technical Reports Server (NTRS)
Edwards, Dean B. (Inventor); Rippel, Wally E. (Inventor)
1986-01-01
A sealed, low maintenance battery (10, 100) is formed of a casing (14, 102) having a sealed lid (12, 104) enclosing cell compartments (22, 110) formed by walls (24, 132). The cells comprise a stack (26) of horizontally disposed negative active plates (30) and positive active plates (28) interspersed with porous, resilient separator sheets (30). Each plate has a set of evenly spaced tigs (40, 41) disposed on one side thereof; like polarity tigs being disposed on one side and opposite polarity tigs on the other. Columns of tigs are electrically and mechanically joined by vertical bus bars (46). The bus bars contain outwardly projecting arms (56) of opposite polarity which are electrically joined at each partition wall (24) to electrically connect the cells in series. The stack is compressed by biasing means such as resilient pad (58) attached to the lid or by joining the tigs (52) to the post (48) at a distance less than the thickness of the mat (124). The end bus bars (46) are joined to straps (60, 62) which connect to the terminals (16, 18). The negative plates contain more capacity than the positive plates and the starved electrolyte imbibed in the separator sheets permits pressurized operation during which oxygen diffuses through the separator sheet to the negative plate where it recombines. Excess pressure is relieved through the vent and pressure relief valve (20).
Human DNA ligase III bridges two DNA ends to promote specific intermolecular DNA end joining
Kukshal, Vandna; Kim, In-Kwon; Hura, Gregory L.; Tomkinson, Alan E.; Tainer, John A.; Ellenberger, Tom
2015-01-01
Mammalian DNA ligase III (LigIII) functions in both nuclear and mitochondrial DNA metabolism. In the nucleus, LigIII has functional redundancy with DNA ligase I whereas LigIII is the only mitochondrial DNA ligase and is essential for the survival of cells dependent upon oxidative respiration. The unique LigIII zinc finger (ZnF) domain is not required for catalytic activity but senses DNA strand breaks and stimulates intermolecular ligation of two DNAs by an unknown mechanism. Consistent with this activity, LigIII acts in an alternative pathway of DNA double strand break repair that buttresses canonical non-homologous end joining (NHEJ) and is manifest in NHEJ-defective cancer cells, but how LigIII acts in joining intermolecular DNA ends versus nick ligation is unclear. To investigate how LigIII efficiently joins two DNAs, we developed a real-time, fluorescence-based assay of DNA bridging suitable for high-throughput screening. On a nicked duplex DNA substrate, the results reveal binding competition between the ZnF and the oligonucleotide/oligosaccharide-binding domain, one of three domains constituting the LigIII catalytic core. In contrast, these domains collaborate and are essential for formation of a DNA-bridging intermediate by adenylated LigIII that positions a pair of blunt-ended duplex DNAs for efficient and specific intermolecular ligation. PMID:26130724
NASA Astrophysics Data System (ADS)
Khalifa, H. E.; Deck, C. P.; Gutierrez, O.; Jacobsen, G. M.; Back, C. A.
2015-02-01
The use of silicon carbide (SiC) composites as structural materials in nuclear applications necessitates the development of a viable joining method. One critical application for nuclear-grade joining is the sealing of fuel within a cylindrical cladding. This paper demonstrates cylindrical joint feasibility using a low activation nuclear-grade joint material comprised entirely of β-SiC. While many papers have considered joining material, this paper takes into consideration the joint geometry and component form factor, as well as the material performance. Work focused specifically on characterizing the strength and permeability performance of joints between cylindrical SiC-SiC composites and monolithic SiC endplugs. The effects of environment and neutron irradiation were not evaluated in this study. Joint test specimens of different geometries were evaluated in their as-fabricated state, as well as after being subjected to thermal cycling and partial mechanical loading. A butted scarf geometry supplied the best combination of high strength and low permeability. A leak rate performance of 2 × 10-9 mbar l s-1 was maintained after thermal cycling and partial mechanical loading and sustained applied force of 3.4 kN, or an apparent strength of 77 MPa. This work shows that a cylindrical SiC-SiC composite tube sealed with a butted scarf endplug provides out-of-pile strength and permeability performance that meets light water reactor design requirements.
Miriyev, Aslan; Grützner, Steffen; Krüger, Lutz; Kalabukhov, Sergey; Frage, Nachum
2016-01-01
A combination of the high damage tolerance of TRIP-steel and the extremely low thermal conductivity of partially stabilized zirconia (PSZ) can provide controlled thermal-mechanical properties to sandwich-shaped composite specimens comprising these materials. Sintering the (TRIP-steel-PSZ)/PSZ sandwich in a single step is very difficult due to differences in the sintering temperature and densification kinetics of the composite and the ceramic powders. In the present study, we successfully applied a two-step approach involving separate SPS consolidation of pure (3Y)-TZP and composites containing 20 vol % TRIP-steel, 40 vol % Al2O3 and 40 vol % (3Y)-TZP ceramic phase, and subsequent diffusion joining of both sintered components in an SPS apparatus. The microstructure and properties of the sintered and bonded specimens were characterized. No defects at the interface between the TZP and the composite after joining in the 1050–1150 °C temperature range were observed. Only limited grain growth occurred during joining, while crystallite size, hardness, shear strength and the fraction of the monoclinic phase in the TZP ceramic virtually did not change. The slight increase of the TZP layer’s fracture toughness with the joining temperature was attributed to the effect of grain size on transformation toughening. PMID:28773680
The influence of joint technologies on ELV recyclability.
Soo, Vi Kie; Compston, Paul; Doolan, Matthew
2017-10-01
Stricter vehicle emission legislation has led to the increasing use of lightweight materials and multi-material concepts to reduce the vehicle mass. To account for the complexity of multi-material vehicle designs, the choice of joining techniques used is becoming more diverse. Moreover, the different material combinations, and their respective joining methods play an important role in determining the potential of full material separation in a closed-loop system. This paper evaluates the types of joining technologies used in the automotive industry, and identifies those that hinder the sorting of ELV materials. The study is based on an industrial shredding trial of car doors. Observations from the case study showed that steel screws and bolts are increasingly used to combine different material types and are less likely to be perfectly liberated during the shredding process. The characteristics of joints that lead to impurities and valuable material losses, such as joint strength, material type, size, diameter, location, and protrusion level, can influence the material liberation in the current sorting practices and thus, lead to ELV waste minimisation. Additionally, the liberation of joints is also affected by the density and thickness of materials being joined. Correlation analyses are carried out to further support the influence of mechanical screws and bolts on material separation efficiencies. The observations are representative of the initial phases of current global ELV sorting practices. Copyright © 2017 Elsevier Ltd. All rights reserved.
Human DNA ligase III bridges two DNA ends to promote specific intermolecular DNA end joining.
Kukshal, Vandna; Kim, In-Kwon; Hura, Gregory L; Tomkinson, Alan E; Tainer, John A; Ellenberger, Tom
2015-08-18
Mammalian DNA ligase III (LigIII) functions in both nuclear and mitochondrial DNA metabolism. In the nucleus, LigIII has functional redundancy with DNA ligase I whereas LigIII is the only mitochondrial DNA ligase and is essential for the survival of cells dependent upon oxidative respiration. The unique LigIII zinc finger (ZnF) domain is not required for catalytic activity but senses DNA strand breaks and stimulates intermolecular ligation of two DNAs by an unknown mechanism. Consistent with this activity, LigIII acts in an alternative pathway of DNA double strand break repair that buttresses canonical non-homologous end joining (NHEJ) and is manifest in NHEJ-defective cancer cells, but how LigIII acts in joining intermolecular DNA ends versus nick ligation is unclear. To investigate how LigIII efficiently joins two DNAs, we developed a real-time, fluorescence-based assay of DNA bridging suitable for high-throughput screening. On a nicked duplex DNA substrate, the results reveal binding competition between the ZnF and the oligonucleotide/oligosaccharide-binding domain, one of three domains constituting the LigIII catalytic core. In contrast, these domains collaborate and are essential for formation of a DNA-bridging intermediate by adenylated LigIII that positions a pair of blunt-ended duplex DNAs for efficient and specific intermolecular ligation. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.
Nonlinear Aeroelastic Analysis of Joined-Wing Configurations
NASA Astrophysics Data System (ADS)
Cavallaro, Rauno
Aeroelastic design of joined-wing configurations is yet a relatively unexplored topic which poses several difficulties. Due to the overconstrained nature of the system combined with structural geometric nonlinearities, the behavior of Joined Wings is often counterintuitive and presents challenges not seen in standard layouts. In particular, instability observed on detailed aircraft models but never thoroughly investigated, is here studied with the aid of a theoretical/computational framework. Snap-type of instabilities are shown for both pure structural and aeroelastic cases. The concept of snap-divergence is introduced to clearly identify the true aeroelastic instability, as opposed to the usual aeroelastic divergence evaluated through eigenvalue approach. Multi-stable regions and isola-type of bifurcations are possible characterizations of the nonlinear response of Joined Wings, and may lead to branch-jumping phenomena well below nominal critical load condition. Within this picture, sensitivity to (unavoidable) manufacturing defects could have potential catastrophic effects. The phenomena studied in this work suggest that the design process for Joined Wings needs to be revisited and should focus, when instability is concerned, on nonlinear post-critical analysis since linear methods may provide wrong trend indications and also hide potentially catastrophical situations. Dynamic aeroelastic analyses are also performed. Flutter occurrence is critically analyzed with frequency and time-domain capabilities. Sensitivity to different-fidelity aeroelastic modeling (fluid-structure interface algorithm, aerodynamic solvers) is assessed showing that, for some configurations, wake modeling (rigid versus free) has a strong impact on the results. Post-flutter regimes are also explored. Limit cycle oscillations are observed, followed, in some cases, by flip bifurcations (period doubling) and loss of periodicity of the solution. Aeroelastic analyses are then carried out on a realistic PrantlPlane to understand effects induced by freeplay of mobile surfaces. Conclusive work is also performed to study the interaction between rigid body and elastic modes, assessing the occurrence of bodyfreedom flutter.
Li, Jinhua; Xia, Dongpo; Sun, Binghua; Zhang, Dao
2015-01-01
Collective behavior has recently attracted a great deal of interest in both natural and social sciences. While the role of leadership has been closely scrutinized, the rules used by joiners in collective decision making have received far less attention. Two main hypotheses have been proposed concerning these rules: mimetism and quorum. Mimetism predicts that individuals are increasingly likely to join collective behavior as the number of participants increases. It can be further divided into selective mimetism, where relationships among the participants affect the process, and anonymous mimetism, where no such effect exists. Quorum predicts that a collective behavior occurs when the number of participants reaches a threshold. To probe into which rule is used in collective decision making, we conducted a study on the joining process in a group of free-ranging Tibetan macaques (Macaca thibetana) in Huangshan, China using a combination of all-occurrence and focal animal sampling methods. Our results show that the earlier individuals joined movements, the more central a role they occupied among the joining network. We also found that when less than three adults participated in the first five minutes of the joining process, no entire group movement occurred subsequently. When the number of these early joiners ranged from three to six, selective mimetism was used. This means higher rank or closer social affiliation of early joiners could be among the factors of deciding whether to participate in movements by group members. When the number of early joiners reached or exceeded seven, which was the simple majority of the group studied, entire group movement always occurred, meaning that the quorum rule was used. Putting together, Macaca thibetana used a combination of selective mimetism and quorum, and early joiners played a key role in deciding which rule should be used. PMID:25992882
Sultana, T; Georgiev, G L; Baird, R J; Auner, G W; Newaz, G; Patwa, R; Herfurth, H J
2009-07-01
Biomedical devices and implants require precision joining for hermetic sealing which can be achieved with low power lasers. The effect of two different thin metal film coating methods was studied in transmission laser micro-joints of titanium-coated glass and polyimide. The coating methods were cathodic arc physical vapor deposition (CA-PVD) and electron beam evaporation (EB-PVD). Titanium-coated glass joined to polyimide film can have neural electrode application. The improvement of the joint quality will be essential for robust performance of the device. Low power fiber laser (wave length = 1100 nm) was used for transmission laser micro-joining of thin titanium (Ti) film (approximately 200 nm) coated Pyrex borosilicate 7740 glass wafer (0.5 mm thick) and polyimide (Imidex) film (0.2 mm thick). Ti film acts as the coupling agent in the joining process. The Ti film deposition rate in the CA-PVD was 5-10 A/s and in the EB-PVD 1.5 A/s. The laser joint strength was measured by a lap shear test, the Ti film surfaces were analyzed by atomic force microscopy (AFM) and the lap shear tested joints were analyzed by optical microscopy and scanning electron microscopy (SEM). The film properties and the failure modes of the joints were correlated to joint strength. The CA-PVD produced around 4 times stronger laser joints than EB-PVD. The adhesion of the Ti film on glass by CA-PVD is better than that of the EB-PVD method. This is likely to be due to a higher film deposition rate and consequently higher adhesion or sticking coefficient for the CA-PVD particles arriving on the substrate compared to that of the EB-PVD film. EB-PVD shows poor laser bonding properties due to the development of thermal hotspots which occurs from film decohesion.
International Symposium on Interfacial Joining and Surface Technology (IJST2013)
NASA Astrophysics Data System (ADS)
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 Details of the committees are available in the PDF