Science.gov

Sample records for pro-opiomelanocortin-derived amidated joining

  1. Sexual dimorphic evolution of metabolic programming in non-genetic non-alimentary mild metabolic syndrome model in mice depends on feed-back mechanisms integrity for pro-opiomelanocortin-derived endogenous substances.

    PubMed

    Loizzo, Stefano; Vella, Stefano; Loizzo, Alberto; Fortuna, Andrea; Di Biase, Antonella; Salvati, Serafina; Frajese, Giovanni V; Agrapart, Vincent; Ramirez Morales, Rafael; Spampinato, Santi; Campana, Gabriele; Capasso, Anna; Galietta, Gabriella; Guarino, Irene; Carta, Stefania; Carru, Ciriaco; Zinellu, Angelo; Ghirlanda, Giovanni; Seghieri, Giuseppe; Renzi, Paolo; Franconi, Flavia

    2010-08-01

    Previously, we showed that our post-natal handling model induces pro-opiomelanocortin-derived (POMC) endogenous systems alterations in male mice at weaning. These alterations last up to adult age, and are at the basis of adult hormonal and metabolic conditions similar to mild metabolic syndrome/type-2 diabetes. Here, we evaluate how sex influences post-natal programming in these metabolic conditions. Subjects are adult control (non-handled) female (NHF) and male (NHM) CD-1 mice; adult post-natal handled female (HF) and male (HM) mice. Handling consists of daily maternal separation (10 min) plus sham injection, from birth to weaning (21 days). In adult handled males (90-days old) we find not only POMC-derived hormones alterations (enhanced basal plasma corticosterone (+91%) and ACTH (+109%)) but also overweight (+5.4%), fasting hyperglycemia (+40%), hypertriglyceridemia (+21%), enhanced brain mRNA expression of hydroxysteroid(11-beta)dehydrogenase type-1 (HSD11B1) (+49%), and decreased mRNA-HSD11B2 (-39%). Conversely, uric acid, creatinine, HDL(C), total cholesterol, glucose and insulin incremental area under-the-curve are not affected. In females, post-natal handling does not produce both hormonal and dysmetabolic diabetes-like changes; but handling enhances n3- and n6-poly-unsaturated, and decreases saturated fatty acids content in erythrocyte membrane composition in HF versus NHF. In conclusion, for the first time we show that female sex in mice exerts effective protection against the hypothalamus-pituitary-adrenal homeostasis disruption induced by our post-natal handling model on POMC cleavage products; endocrine disruption is in turn responsible for altered metabolic programming in male mice. The role of sex hormones is still to be elucidated.

  2. Biosynthesis of amidated joining peptide from pro-adrenocorticotropin-endorphin

    SciTech Connect

    Cullen, E.I.; Mains, R.E. )

    1987-09-01

    Joining peptide is the major alpha-amidated product of pro-ACTH/endorphin (PAE) in AtT-20 corticotropic tumor cells. To study intracellular joining peptide synthesis, affinity purified antibodies directed against gamma-MSH, joining peptide, and ACTH were used to immunoprecipitate extracts from biosynthetically labeled AtT-20 cells. Immunoprecipitates were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and by tryptic peptide mapping on HPLC. In steady labeling experiments, radioactivity in amidated joining peptide (JP) increased roughly linearly with time, in the manner of a final product, whereas radioactivity associated with PAE (1-94)NH2 reached a constant value after 2-4 h, indicating that PAE(1-94)NH2 is an intermediate in the biosynthesis of JP. Radioactivity appeared in ACTH(1-39) well before JP, consistent with a cleavage order in which ACTH is cleaved from PAE(1-95) before JP sequences are cleaved from PAE(1-74). This conclusion was supported by tryptic peptide analyses of immunoprecipitates, which indicated that less than 5% of JP-related material is cleaved from PAE(1-74) before being cleaved from ACTH-related sequences. After a pulse label, radioactivity in PAE(1-94)NH2 reached a peak value after 1 h of chase and declined with a half-life of less than 1 h. Amidated JP increased to a constant level after 2 h of chase. Enough radiolabeled PAE(1-94)NH2 was detected to account for about half of the radioactivity found in amidated JP, indicating that about half of JP-related material is first cleaved from PAE(1-95) before being amidated. This result was corroborated using HPLC purification to determine both amidated and glycine-extended forms of JP.

  3. 60 YEARS OF POMC: Biosynthesis, trafficking, and secretion of pro-opiomelanocortin-derived peptides.

    PubMed

    Cawley, Niamh X; Li, Zhaojin; Loh, Y Peng

    2016-05-01

    Pro-opiomelanocortin (POMC) is a prohormone that encodes multiple smaller peptide hormones within its structure. These peptide hormones can be generated by cleavage of POMC at basic residue cleavage sites by prohormone-converting enzymes in the regulated secretory pathway (RSP) of POMC-synthesizing endocrine cells and neurons. The peptides are stored inside the cells in dense-core secretory granules until released in a stimulus-dependent manner. The complexity of the regulation of the biosynthesis, trafficking, and secretion of POMC and its peptides reflects an impressive level of control over many factors involved in the ultimate role of POMC-expressing cells, that is, to produce a range of different biologically active peptide hormones ready for action when signaled by the body. From the discovery of POMC as the precursor to adrenocorticotropic hormone (ACTH) and β-lipotropin in the late 1970s to our current knowledge, the understanding of POMC physiology remains a monumental body of work that has provided insight into many aspects of molecular endocrinology. In this article, we describe the intracellular trafficking of POMC in endocrine cells, its sorting into dense-core secretory granules and transport of these granules to the RSP. Additionally, we review the enzymes involved in the maturation of POMC to its various peptides and the mechanisms involved in the differential processing of POMC in different cell types. Finally, we highlight studies pertaining to the regulation of ACTH secretion in the anterior and intermediate pituitary and POMC neurons of the hypothalamus.

  4. Post-natal stress-induced endocrine and metabolic alterations in mice at adulthood involve different pro-opiomelanocortin-derived peptides.

    PubMed

    Loizzo, Stefano; Campana, Gabriele; Vella, Stefano; Fortuna, Andrea; Galietta, Gabriella; Guarino, Irene; Costa, Loredana; Capasso, Anna; Renzi, Paolo; Frajese, Giovanni V; Franconi, Flavia; Loizzo, Alberto; Spampinato, Santi

    2010-11-01

    In previous investigations we added a physical stress (mild pain) to the "classical" post-natal psychological stress in male mice, and we found that this combination produced a series of dysmetabolic signs very similar to mild human type-2 diabetes. Here, for the first time we demonstrate that within this diabetes model at least two groups of signs depend on the unbalance of two different endogenous systems. Newborn male mice were daily exposed to stressful procedures for 21 days (brief mother separation plus sham injection). Other groups underwent the same procedure, and also received naloxone (Na) to block μ-δ endogenous receptors, or a phosphorothioate antisense oligonucleotide (AS) directed against pro-opiomelanocortin (POMC)-mRNA [to block adrenocorticotropin (ACTH)- and POMC-derived opioid peptides]. Adult mice which received only post-natal stress increased body weight (+7.5%), abdominal overweight (+74%), fasting glycemia (+43%), plasma corticosterone (+110%), plasma (+169%) and pituitary (+153%) ACTH levels. Conversely, hypothalamic ACTH and corticotropin-releasing hormone (CRH) were reduced (-70% and -75%, respectively). Neonatal AS administration reverted all parameters to control values. Neonatal naloxone had little or no influence on glucose, corticosterone, ACTH, CRH levels, whereas it prevented body overweight and abdominal overweight. We conclude that, within this type-2 diabetes model in male mice at least two endocrino-neurohumoral systems are damaged, one concerning the opioid system, and the other concerning HPA hormones. The use of the two drugs was of primary importance to demonstrate this statement, and to demonstrate that these two groups of signs could be defined as "separate entities" following our complex post-natal stress model.

  5. Explosive Joining

    NASA Technical Reports Server (NTRS)

    1989-01-01

    Laurence J. Bement of Langley Research Center invented a technique to permit metal joining operations under hazardous or inaccessible conditions. The process, which provides a joint with double the strength of the parent metal, involves the use of very small quantities of ribbon explosive to create hermetically sealed joints. When the metal plates are slammed together by the explosion's force, joining is accomplished. The collision causes a skin deep melt and ejection of oxide films on the surfaces, allowing a linkup of electrons that produce superstrong, uniform joints. The technique can be used to join metals that otherwise would not join and offers advantages over mechanical fasteners and adhesives. With Langley assistance, Demex International Ltd. refined and commercialized the technology. Applications include plugging leaking tubes in feedwater heaters. Demex produces the small plugs, associated sleeves and detonators. The technology allows faster plugging, reduces downtime, cuts plugging costs and increases reliability.

  6. Ceramic joining

    SciTech Connect

    Loehman, R.E.

    1996-04-01

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

  7. Precision Joining Center

    SciTech Connect

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

    1991-08-01

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

  8. Precision Joining Center

    NASA Technical Reports Server (NTRS)

    Powell, John W.

    1991-01-01

    The establishment of a Precision Joining Center (PJC) is proposed. The PJC will be a cooperatively operated center with participation from U.S. private industry, the Colorado School of Mines, and various government agencies, including the Department of Energy's Nuclear Weapons Complex (NWC). The PJC's primary mission will be as a training center for advanced joining technologies. This will accomplish the following objectives: (1) it will provide an effective mechanism to transfer joining technology from the NWC to private industry; (2) it will provide a center for testing new joining processes for the NWC and private industry; and (3) it will provide highly trained personnel to support advance joining processes for the NWC and private industry.

  9. Joining of dissimilar materials

    DOEpatents

    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.

  10. Pulse joining cartridges

    DOEpatents

    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.

  11. Joining Steel Armor - Intermix

    DTIC Science & Technology

    1979-03-01

    TARADCOM a d ki Lk A el B~ 0el RWET0 TECHNICAL REPORT NO. 12311 JOINING STEEL ARMOR - INTERMIX March 1979 U U * S* ’ "U .by B. . A.SCEV * U...authorized documents. O "if TECHNICAL REPORT NO. 12311 JOINING STEEL ARMOR - INTERMIX BY B. A. SCHEVO March 1979 AMS: 3197..6D.4329 TARADCOM ARMOR AND...Intermix Process ...... ........ 3 Test Procedures - Intermix Armor ........ ......... 4 Mock Hull ................. ..................... 5 Results

  12. Joined concentric tubes

    DOEpatents

    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.

  13. Joined Beryllium Mirror Demonstrator

    NASA Technical Reports Server (NTRS)

    Stahl, H. Philip; Parsonage, Tom; Burdine, Robert (Technical Monitor)

    2001-01-01

    Fabrications of large Beryllium optical components are fundamentally limited by available facility capabilities. To overcome this limitation, NASA funded Brush Wellman Corp to study a Be joining process. Four 76 mm diameters samples and a 0.5 mm diameter Joined Beryllium Mirror Demonstrator (JBMD) were fabricated. This presentation will review the fabrication of these samples and summarize the results of their cryogenic testing at MSFCs XRCF.

  14. Advanced Joining Technology

    DTIC Science & Technology

    1982-01-01

    cracking in welding of alloy 713C . Filler-metal thermal expansion characteristics and mechanical properties may influence HAZ soundness. Filler-metal...aluminum-, and titanium-base alloys ; superalloys (both nickel and cobalt base); and ceramics. The detailed review of ceramic-to-ceramic and ceramic...building. The Air Force has funded work on forming and joining of aluminum powder metal alloys , and the Army conducted a metals joining technology

  15. Duct Joining System

    DOEpatents

    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.

  16. Duct joining system

    DOEpatents

    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.

  17. Come Join the Band

    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…

  18. 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.

  19. Joined ceramic product

    DOEpatents

    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.

  20. 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.

  1. Method of joining ceramics

    DOEpatents

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

    2000-01-01

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

  2. Joining of Beryllium

    SciTech Connect

    Goldberg, A

    2006-02-01

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

  3. Cleavage of an amide bond by a ribozyme

    NASA Technical Reports Server (NTRS)

    Dai, X.; De Mesmaeker, A.; Joyce, G. F.; Miller, S. L. (Principal Investigator)

    1995-01-01

    A variant form of a group I ribozyme, optimized by in vitro evolution for its ability to catalyze magnesium-dependent phosphoester transfer reactions involving DNA substrates, also catalyzes the cleavage of an unactivated alkyl amide when that linkage is presented in the context of an oligodeoxynucleotide analog. Substrates containing an amide bond that joins either two DNA oligos, or a DNA oligo and a short peptide, are cleaved in a magnesium-dependent fashion to generate the expected products. The first-order rate constant, kcat, is 0.1 x 10(-5) min-1 to 1 x 10(-5) min-1 for the DNA-flanked substrates, which corresponds to a rate acceleration of more than 10(3) as compared with the uncatalyzed reaction.

  4. DNA-Catalyzed Amide Hydrolysis

    PubMed Central

    Zhou, Cong; Avins, Joshua L.; Klauser, Paul C.; Brandsen, Benjamin M.; Lee, Yujeong; Silverman, Scott K.

    2016-01-01

    DNA catalysts (deoxyribozymes) for a variety of reactions have been identified by in vitro selection. However, for certain reactions this identification has not been achieved. One important example is DNA-catalyzed amide hydrolysis, for which a previous selection experiment instead led to DNA-catalyzed DNA phosphodiester hydrolysis. Subsequent efforts in which the selection strategy deliberately avoided phosphodiester hydrolysis led to DNA-catalyzed ester and aromatic amide hydrolysis, but aliphatic amide hydrolysis has been elusive. In the present study, we show that including modified nucleotides that bear protein-like functional groups (any one of primary amino, carboxyl, or primary hydroxyl) enables identification of amide-hydrolyzing deoxyribozymes. In one case, the same deoxyribozyme sequence without the modifications still retains substantial catalytic activity. Overall, these findings establish the utility of introducing protein-like functional groups into deoxyribozymes for identifying new catalytic function. The results also suggest the longer-term feasibility of deoxyribozymes as artificial proteases. PMID:26854515

  5. HIP Joining of Cemented Carbides

    SciTech Connect

    Derby, B.; Miodownik, M.

    1999-04-01

    Hot Isostatic Pressing (HIP) is investigated as a technique for joining the cermet WC-15% Co to itself. Encapsulation of the specimens prior to HIPing was carried out using steel encapsulation, glass encapsulation and self encapsulation. The bonds were evaluated using a four point bend method. It is shown that the glass and steel encapsulation methods have a number of inherent problems which make them inappropriate for near net shape processing. In contrast the novel self encapsulation method, described for the first time in this communication, is both simple and effective, producing joined material with bulk strength. The concept of self encapsulation is potentially widely applicable for joining composite materials.

  6. Environmentally compliant adhesive joining technology

    SciTech Connect

    Tira, J.S.

    1996-08-01

    Adhesive joining offers one method of assembling products. Advantages of adhesive joining/assembly include distribution of applied forces, lighter weight, appealing appearance, etc. Selecting environmentally safe adhesive materials and accompanying processes is paramount in today`s business climate if a company wants to be environmentally conscious and stay in business. Four areas of adhesive joining (adhesive formulation and selection, surface preparation, adhesive bonding process, waste and pollution generation/cleanup/management) all need to be carefully evaluated before adhesive joining is selected for commercial as well as military products. Designing for six sigma quality must also be addressed in today`s global economy. This requires material suppliers and product manufacturers to work even closer together.

  7. Spain to Join ESO

    NASA Astrophysics Data System (ADS)

    2006-02-01

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

  8. "Parent Unions" Join Policy Debates

    ERIC Educational Resources Information Center

    Cavanagh, Sean

    2012-01-01

    Whether they're organizing events, buttonholing legislators, or simply trading ideas and information, a growing number of "parent unions" are attempting to stake out a place in policy debates over education in states and districts, amid a crowded field of actors and advocates. As the term implies, some of these organizations see…

  9. 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.

  10. Bonding and Joining Technology: a Compilation

    NASA Technical Reports Server (NTRS)

    1971-01-01

    A collection of articles concerning the methods and uses of aerospace bonding and joining techniques in industrial processes is presented. Data include methods to bond and join metal components, joining techniques for adhesive materials, and shop hints for bonding and joining a variety of other items and materials.

  11. Automatic connector joins structural columns

    NASA Technical Reports Server (NTRS)

    Jacquemin, G. G.

    1980-01-01

    Connector snap-locks over toothed bolthead mounted on column end, forming rigid joint that will not bend or twist. Connector is used in conventional construction to install temporary structures or as mechanical coupler. Up to nine receptacles can be clustered in one node to join up to nine converging columns.

  12. Joining NZP ceramics. Final report

    SciTech Connect

    Nicklas, K.D.; Richey, M.W.; Holcombe, C.E. Jr.; Santella, M.L.

    1995-09-26

    Objective was to assess techniques for joining NZP ceramics, a new family of ceramic materials that have low coefficient of thermal expansion, low thermal conductivity, and excellent thermal-shock resistance. Initially, the authors evaluated laser-beam welding over volatile fluxing agents (ferric oxide, copper oxide, boric acid, and boron nitride). They also examined other laser, arc-welding, brazing, and cold joining techniques. The NZP materials were capable of sustaining the thermal stresses associated with these joining processes without substantial cracking. Of the volatile fluxes, only the copper oxide promoted weld fusion. Efforts to accomplish fusion by laser-beam welding over copper, titanium, stainless steel, yttrium barium copper oxide, fused silica glass, and mullite/alumina were unsuccessful. Gas-tungsten arc welding accompanied by porosity, irregularities, and cracking was achieved on copper sheet sandwiched between NZP tiles. Attempts at conventional oxy-acetylene welding and torch brazing were unproductive. Silica-based oxide mixtures and copper oxide-based materials show potential for development into filler materials for furnace brazing, and phosphate-based cements show promise as a means of cold joining.

  13. The Join-Up Meeting

    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.

  14. Vibrational relaxation pathways of amide I and amide II modes in N-methylacetamide.

    PubMed

    Piatkowski, L; Bakker, H J

    2012-04-28

    We studied the vibrational energy relaxation mechanisms of the amide I and amide II modes of N-methylacetamide (NMA) monomers dissolved in bromoform using polarization-resolved femtosecond two-color vibrational spectroscopy. The results show that the excited amide I vibration transfers its excitation energy to the amide II vibration with a time constant of 8.3 ± 1 ps. In addition to this energy exchange process, we observe that the excited amide I and amide II vibrations both relax to a final thermal state. For the amide I mode this latter process dominates the vibrational relaxation of this mode. We find that the vibrational relaxation of the amide I mode depends on frequency which can be well explained from the presence of two subbands with different vibrational lifetimes (~1.1 ps on the low frequency side and ~2.7 ps on the high frequency side) in the amide I absorption spectrum.

  15. Joining of polymer composite materials

    SciTech Connect

    Magness, F.H.

    1990-11-01

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

  16. 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.

  17. Joining of tubes by gas detonation forming

    NASA Astrophysics Data System (ADS)

    Jenkouk, Vahid; Patil, Sandeep; Markert, Bernd

    2016-08-01

    For many applications, such as in structural components, it is required to join two tubes - sometimes with dissimilar material properties. Only few research studies have investigated the joining of tubular metallic components by means of high-velocity forming processes. In this paper, we present the novel process of joining of two tubes by a gas detonation pressure wave. In particular, the joining of a copper and a steel tube is discussed by means of a finite element study and a conducted experiment.

  18. Direct amidation of esters with nitroarenes

    PubMed Central

    Cheung, Chi Wai; Ploeger, Marten Leendert; Hu, Xile

    2017-01-01

    Esters are one of the most common functional groups in natural and synthetic products, and the one-step conversion of the ester group into other functional groups is an attractive strategy in organic synthesis. Direct amidation of esters is particularly appealing due to the omnipresence of the amide moiety in biomolecules, fine chemicals, and drug candidates. However, efficient methods for direct amidation of unactivated esters are still lacking. Here we report nickel-catalysed reductive coupling of unactivated esters with nitroarenes to furnish in one step a wide range of amides bearing functional groups relevant to the development of drugs and agrochemicals. The method has been used to expedite the syntheses of bio-active molecules and natural products, as well as their post-synthetic modifications. Preliminary mechanistic study indicates a reaction pathway distinct from conventional amidation methods using anilines as nitrogen sources. The work provides a novel and efficient method for amide synthesis. PMID:28345585

  19. Flexible Friction Stir Joining Technology

    SciTech Connect

    Feng, Zhili; Lim, Yong Chae; Mahoney, Murray; Sanderson, Samuel; Larsen, Steve; Steel, Russel; Fleck, Dale; Fairchild, Doug P; Wasson, Andrew J; Babb, Jon; Higgins, Paul

    2015-07-23

    Reported herein is the final report on a U.S. Department of Energy (DOE) Advanced Manufacturing Office (AMO) project with industry cost-share that was jointly carried out by Oak Ridge National Laboratory (ORNL), ExxonMobil Upstream Research Company (ExxonMobil), and MegaStir Technologies (MegaStir). The project was aimed to advance the state of the art of friction stir welding (FSW) technology, a highly energy-efficient solid-state joining process, for field deployable, on-site fabrications of large, complex and thick-sectioned structures of high-performance and high-temperature materials. The technology innovations developed herein attempted to address two fundamental shortcomings of FSW: 1) the inability for on-site welding and 2) the inability to weld thick section steels, both of which have impeded widespread use of FSW in manufacturing. Through this work, major advance has been made toward transforming FSW technology from a “specialty” process to a mainstream materials joining technology to realize its pervasive energy, environmental, and economic benefits across industry.

  20. Multicomponent Synthesis of α-Branched Amides

    PubMed Central

    DeBenedetto, Mikkel V.; Green, Michael E.; Wan, Shuangyi; Park, Jung-Hyun; Floreancig, Paul E.

    2009-01-01

    α-Branched amides are prepared by multicomponent reactions in which nitriles undergo hydrozirconation to form metalloimines that react with acyl chlorides. The resulting acylimines react with a variety of π-nucleophiles in the presence of Lewis acids to form the desired amides. PMID:19152262

  1. Catalytic synthesis of amides via aldoximes rearrangement.

    PubMed

    Crochet, Pascale; Cadierno, Victorio

    2015-02-14

    Amide bond formation reactions are among the most important transformations in organic chemistry because of the widespread occurrence of amides in pharmaceuticals, natural products and biologically active compounds. The Beckmann rearrangement is a well-known method to generate secondary amides from ketoximes. However, under the acidic conditions commonly employed, aldoximes RHC=NOH rarely rearrange into the corresponding primary amides RC(=O)NH2. In recent years, it was demonstrated that this atom-economical transformation can be carried out efficiently and selectively with the help of metal catalysts. Several homogeneous and heterogenous systems have been described. In addition, protocols offering the option to generate the aldoximes in situ from the corresponding aldehydes and hydroxylamine, or even from alcohols, have also been developed, as well as a series of tandem processes allowing the access to N-substituted amide products. In this Feature article a comprehensive overview of the advances achieved in this particular research area is presented.

  2. Join-Graph Propagation Algorithms

    PubMed Central

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

    2010-01-01

    The paper investigates parameterized approximate message-passing schemes that are based on bounded inference and are inspired by Pearl's belief propagation algorithm (BP). We start with the bounded inference mini-clustering algorithm and then move to the iterative scheme called Iterative Join-Graph Propagation (IJGP), that combines both iteration and bounded inference. Algorithm IJGP belongs to the class of Generalized Belief Propagation algorithms, a framework that allowed connections with approximate algorithms from statistical physics and is shown empirically to surpass the performance of mini-clustering and belief propagation, as well as a number of other state-of-the-art algorithms on several classes of networks. We also provide insight into the accuracy of iterative BP and IJGP by relating these algorithms to well known classes of constraint propagation schemes. PMID:20740057

  3. Simplified Explosive Joining of Tubes to Fittings

    NASA Technical Reports Server (NTRS)

    Bement, L. J.; Bailey, J. W.; Perry, R.; Finch, M. S.

    1987-01-01

    Technique simplifies tube-to-fitting joining, as compared to fusion welding, and provides improvement on standard procedures used to join tubes explosively to tube fittings. Special tool inserted into tube to be joined. Tool allows strip of ribbon explosive to be placed right at joint. Ribbon explosive and mild detonating fuse allows use of smaller charge. Assembled tool storable, and process amenable to automation. Assembly of components, insertion of tool into weld site, and joining operation mechanized without human contact. Used to assemble components in nuclear reactors or in other environments hostile to humans.

  4. 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.

  5. Microorganisms hydrolyse amide bonds; knowledge enabling read-across of biodegradability of fatty acid amides.

    PubMed

    Geerts, Roy; Kuijer, Patrick; van Ginkel, Cornelis G; Plugge, Caroline M

    2014-07-01

    To get insight in the biodegradation and potential read-across of fatty acid amides, N-[3-(dimethylamino)propyl] cocoamide and N-(1-ethylpiperazine) tall oil amide were used as model compounds. Two bacteria, Pseudomonas aeruginosa PK1 and Pseudomonas putida PK2 were isolated with N-[3-(dimethylamino)propyl] cocoamide and its hydrolysis product N,N-dimethyl-1,3-propanediamine, respectively. In mixed culture, both strains accomplished complete mineralization of N-[3-(dimethylamino)propyl] cocoamide. Aeromonas hydrophila PK3 was enriched with N-(1-ethylpiperazine) tall oil amide and subsequently isolated using agar plates containing dodecanoate. N-(2-Aminoethyl)piperazine, the hydrolysis product of N-(1-ethylpiperazine) tall oil amide, was not degraded. The aerobic biodegradation pathway for primary and secondary fatty acid amides of P. aeruginosa and A. hydrophila involved initial hydrolysis of the amide bond producing ammonium, or amines, where the fatty acids formed were immediately metabolized. Complete mineralization of secondary fatty acid amides depended on the biodegradability of the released amine. Tertiary fatty acid amides were not transformed by P. aeruginosa or A. hydrophila. These strains were able to utilize all tested primary and secondary fatty acid amides independent of the amine structure and fatty acid. Read-across of previous reported ready biodegradability results of primary and secondary fatty acid amides is justified based on the broad substrate specificity and the initial hydrolytic attack of the two isolates PK1 and PK3.

  6. Joining of advanced materials by superplastic deformation

    DOEpatents

    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.

  7. Joining of advanced materials by superplastic deformation

    DOEpatents

    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.

  8. Efficient Joins with Compressed Bitmap Indexes

    SciTech Connect

    Computational Research Division; Madduri, Kamesh; Wu, Kesheng

    2009-08-19

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

  9. 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.

  10. Microwave joining of SiC

    SciTech Connect

    Silberglitt, R.; Ahmad, I.; Tian, Y.L.

    1997-04-01

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

  11. Joining of ceramics for high temperature applications

    NASA Technical Reports Server (NTRS)

    Vilpas, Martti

    1987-01-01

    Summarized is a literature survey of the methods for joining ceramics to ceramics or ceramics to metals for high temperature applications. Also mechanical properties and potential applications of the joints are considered. The joining of ceramics is usually carried out by brazing or diffusion bonding. Especially the latter has been found useful, increasing the application of bonded ceramics. The possibility of using electron beam and laser beam welding for joining ceramics has also recently been investigated. The bonding of ceramics has found numerous applications typical for high operating temperatures, i.e., sensors and thermocouples.

  12. Microwave joining of high-purity alumina

    SciTech Connect

    Cozzi, A.D.; Clark, D.E.; Ferber, M.K.

    1996-12-31

    Microwave hybrid heating (MHH) was used to join 99.5% pure alumina pieces 25 mm diameter and 25 mm long using 94% pure alumina as the interlayer material. The interlayer material was cut from a rod into discs approximately 2 mm thick. Joining was performed in a home model microwave oven. Temperatures for joining ranged from 1450{degrees}C to 1550{degrees}C and pressures from 1-3 MPa. For comparison, similar joints were made in a conventional furnace. Joined specimens were tested using four-point bend at room temperature. Statistical analysis was utilized to determine the relative effect of the different processing parameters on the strength of the joint.

  13. Steps to Join Green Power Partnership

    EPA Pesticide Factsheets

    The U.S. EPA's Green Power Partnership is a voluntary partnership program designed to reduce the environmental impact of electricity generation by promoting renewable energy. This page details steps organizations should take to join the Partnership.

  14. Synthesis of Amide Functionalized Carbon Nanotubes

    DTIC Science & Technology

    2007-01-01

    amide-linked SWNTs. Through FT-IR spectroscopy, Raman spectroscopy and TGA analysis it was proven that the intermediate compounds were successfully...analysis (TGA). Figure 4 shows the TGA data for SWNT-COOH, SWNT-NH2 and SWNT 4 at a heating rate of 10 oC/min in the presence of argon. The TGA ... analysis shows a major decline in mass for the amide- interconnected nanotubes between the 200 oC to 400 oC region. Weight loss due to functionalization

  15. Polyimides Containing Amide And Perfluoroisopropyl Links

    NASA Technical Reports Server (NTRS)

    Dezem, James F.

    1993-01-01

    New polyimides synthesized from reactions of aromatic hexafluoroisopropyl dianhydrides with asymmetric amide diamines. Soluble to extent of at least 10 percent by weight at temperature of about 25 degrees C in common amide solvents such as N-methylpyrrolidone, N,N-dimethylacetamide, and N,N-dimethylformamide. Polyimides form tough, flexible films, coatings, and moldings. Glass-transition temperatures ranged from 300 to 365 degrees C, and crystalline melting temperatures observed between 543 and 603 degrees C. Display excellent physical, chemical, and electrical properties. Useful as adhesives, laminating resins, fibers, coatings for electrical and decorative purposes, films, wire enamels, and molding compounds.

  16. To Join or Not to Join: School Counselors as a Case Study in Professional Membership

    ERIC Educational Resources Information Center

    Bauman, Sheri

    2008-01-01

    School counselors were surveyed regarding their choice to join or not join their professional organization. Members and nonmembers differed on the following: whether participants' graduate program emphasized professional membership, membership status of colleagues, the belief that professional organizations advance the field, and the belief that…

  17. 40 CFR 721.10691 - Fatty acid amide (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Fatty acid amide (generic). 721.10691... Substances § 721.10691 Fatty acid amide (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as fatty acid amide (PMN P-13-267) is...

  18. 40 CFR 721.10320 - Fatty acid amide (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Fatty acid amide (generic). 721.10320... Substances § 721.10320 Fatty acid amide (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as fatty acid amide (PMN P-03-186) is...

  19. 40 CFR 721.10463 - Fatty acid amides (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Fatty acid amides (generic). 721.10463... Substances § 721.10463 Fatty acid amides (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as fatty acid amides (PMN...

  20. 40 CFR 721.10687 - Fatty acid amide hydrochlorides (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Fatty acid amide hydrochlorides... Specific Chemical Substances § 721.10687 Fatty acid amide hydrochlorides (generic). (a) Chemical substance... fatty acid amide hydrochlorides (PMNs P-13-201, P-13-203, P-13-204, P-13-205, P-13-206, P-13-207,...

  1. 40 CFR 721.10680 - Fatty acid amides (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Fatty acid amides (generic). 721.10680... Substances § 721.10680 Fatty acid amides (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substances identified generically as fatty acid amides (PMNs...

  2. 40 CFR 721.10320 - Fatty acid amide (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Fatty acid amide (generic). 721.10320... Substances § 721.10320 Fatty acid amide (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as fatty acid amide (PMN P-03-186) is...

  3. 40 CFR 721.10320 - Fatty acid amide (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Fatty acid amide (generic). 721.10320... Substances § 721.10320 Fatty acid amide (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as fatty acid amide (PMN P-03-186) is...

  4. 40 CFR 721.10463 - Fatty acid amides (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Fatty acid amides (generic). 721.10463... Substances § 721.10463 Fatty acid amides (generic). (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as fatty acid amides (PMN...

  5. Low temperature joining of ceramic composites

    DOEpatents

    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.

  6. Low temperature joining of ceramic composites

    DOEpatents

    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.

  7. Low temperature joining of ceramic composites

    DOEpatents

    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.

  8. Low temperature joining of ceramic composites

    DOEpatents

    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.

  9. Low temperature joining of ceramic composites

    DOEpatents

    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.

  10. Joining of porous silicon carbide bodies

    DOEpatents

    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.

  11. Joining Techniques for Ferritic ODS Alloys

    SciTech Connect

    V.G. Krishnardula; V.G. Krishnardula; D.E. Clark; T.C. Totemeier

    2005-06-01

    This report presents results of research on advanced joining techniques for ferritic oxide-dispersion strengthened alloys MA956 and PM2000. The joining techniques studied were resistance pressure welding (also known as pressure forge welding), transient liquid phase bonding, and diffusion bonding. All techniques were shown to produce sound joints in fine-grained, unrecrystallized alloys. Post-bond heat treatment to produce a coarse-grained, recrystallized microstructure resulted in grain growth across the bondline for transient liquid phase and diffusion bonds, giving microstructures essentially identical to that of the parent alloy in the recrystallized condition. The effects of bond orientation, boron interlayer thickness, and bonding parameters are discussed for transient liquid phase and diffusion bonding. The report concludes with a brief discussion of ODS joining techniques and their applicability to GEN IV reactor systems.

  12. Fluxing agent for metal cast joining

    DOEpatents

    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.

  13. 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.

  14. Flexible coiled spline securely joins mating cylinders

    NASA Technical Reports Server (NTRS)

    Coppernol, R. W.

    1966-01-01

    Mating cylindrical members are joined by spline to form an integral structure. The spline is made of tightly coiled, high tensile-strength steel spiral wire that fits a groove between the mating members. It provides a continuous bearing surface for axial thrust between the members.

  15. Deformation and Forming of Joined Materials

    SciTech Connect

    Carsley, John; Hovanski, Yuri; Clarke, Kester D.; Krajewski, Paul E.

    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.

  16. Microwave joining of SiC

    SciTech Connect

    Silberglitt, R.; Ahmad, I.; Black, W.M.

    1995-05-01

    The purpose of this work is to optimize the properties of SiC-SiC joints made using microwave energy. The current focus is on optimization of time-temperature profiles, production of SiC from chemical precursors, and design of new applicators for joining of long tubes.

  17. METHOD FOR JOINING ALUMINUM TO STAINLESS STEEL

    DOEpatents

    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.

  18. Friction Stir & Ultrasonic Solid State Joining Magnesium

    SciTech Connect

    Grant, Glenn J.; Hovanski, Yuri; Santella, M. L.

    2009-12-30

    Solid state joining between automotive sheet steel and magnesium alloys was investigated. Both friction stir welding and ultrasonic welding were utilized to study the potential for creating structural bonds between these dissimilar materials. A detailed investigation into the joint characteristics was undertaken including an evaluation of joint strength, microstructure, chemical structures, and alloy formation.

  19. Joining Forces: Working with Spirituality in Organisations.

    ERIC Educational Resources Information Center

    Snell, Robin; And Others

    1991-01-01

    Includes "Joining Forces" (Lindamood); "Spiritual Dimension of the Learning Organisation" (Hawkins); "Management--A 'Spiritual' Foundation?" (Nevard); "Hermit in Organisations" (Murray); "Towards a Spiritual Perspective on Behavior at Work" (Henson); "On Uncertainty" (Adlam); "Spirituality in Organisations" (Lee); "Ecological Organisation" (Conn);…

  20. New Trio Launches to Join Expedition 33

    NASA Video Gallery

    Three new crew members are on their way to join their Expedition 33 crewmates onboard the International Space Station. They launched aboard the Soyuz TMA-06M spacecraft at 6:51 a.m. EDT (5:51 p.m. ...

  1. Advanced Joining Technology: Simple, Strong, and Secure

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The space-age materials that NASA employs in its spacecraft and satellites have different attributes than the building materials that can work for Earthly uses. These materials do not behave like the typical construction materials, and therefore, require new methods for construction. Work done at NASA s Langley Research Center in the realm of active solder joining has led to a new, self-bonding solder that enables high conductivity, as well as the metallic joining of carbon and ceramic materials to a wide range of metals. The original work involved evaluating high- and low-temperature joining technologies for joining carbon composite structures for use in thermal management and reusable launch vehicles. The initial plan for this innovation was to lower the weight of battery packs in satellites. It was a success. NASA scientists found use for this technology in fabricating a thermal management package for battery compartments in the Earth Observing System (EOS) satellites, but it is also being used by the Agency for space radiator panels. Because it is light, simple to use, and economical, NASA will likely find other uses for this solder, just as outside of the Space Agency, this unique bond is finding many practical applications.

  2. Polyimides containing amide and perfluoroisopropylidene connecting groups

    NASA Technical Reports Server (NTRS)

    Dezern, James F. (Inventor)

    1993-01-01

    New, thermooxidatively stable polyimides were prepared from the reaction of aromatic dianhydrides containing isopropylidene bridging groups with aromatic diamines containing amide connecting groups between the rings. Several of these polyimides were shown to be semi-crystalline as evidenced by wide angle x ray scattering and differential scanning calorimetry. Most of the polyimides form tough, flexible films with high tensile properties. These polyimide films exhibit enhanced solubility in organic solvents.

  3. Vibrational lifetimes of protein amide modes

    SciTech Connect

    Peterson, K.A.; Rella, C.A.

    1995-12-31

    Measurement of the lifetimes of vibrational modes in proteins has been achieved with a single frequency infrared pump-probe technique using the Stanford Picosecond Free-electron Laser, These are the first direct measurements of vibrational dynamics in the polyamide structure of proteins. In this study, modes associated with the protein backbone are investigated. Results for the amide I band, which consists mainly of the stretching motion of the carbonyl unit of the amide linkage, show that relaxation from the first vibrational excited level (v=1) to the vibrational ground state (v=0) occurs within 1.5 picoseconds with apparent first order kinetics. Comparison of lifetimes for myoglobin and azurin, which have differing secondary structures, show a small but significant difference. The lifetime for the amide I band of myoglobin is 300 femtoseconds shorter than for azurin. Further measurements are in progress on other backbone vibrational modes and on the temperature dependence of the lifetimes. Comparison of vibrational dynamics for proteins with differing secondary structure and for different vibrational modes within a protein will lead to a greater understanding of energy transfer and dissipation in biological systems. In addition, these results have relevance to tissue ablation studies which have been conducted with pulsed infrared lasers. Vibrational lifetimes are necessary for calculating the rate at which the energy from absorbed infrared photons is converted to equilibrium thermal energy within the irradiated volume. The very fast vibrational lifetimes measured here indicate that mechanisms which involve direct vibrational up-pumping of the amide modes with consecutive laser pulses, leading to bond breakage or weakening, are not valid.

  4. SPPS of protected peptidyl aminoalkyl amides.

    PubMed

    Karavoltsos, Manolis; Mourtas, Spyros; Gatos, Dimitrios; Barlos, Kleomenis

    2002-11-01

    Monophthaloyl diamines derived from naturally occurring amino acids were attached through their free amino functions to resins of the trityl type. The phthaloyl groups were removed by hydrazinolysis, and peptide chains were assembled using Fmoc/tBu-amino acids on the liberated amino functions. The peptidyl aminoalkyl amides obtained were cleaved from the resins by mild acidolysis, with the tBu-side chain protection remaining intact.

  5. Tandem mass spectrometry of amidated peptides.

    PubMed

    Mouls, Laetitia; Subra, Gilles; Aubagnac, Jean-Louis; Martinez, Jean; Enjalbal, Christine

    2006-11-01

    The behavior of C-terminal amidated and carboxylated peptides upon low-energy collision-induced dissociation (CID) was investigated. Two sets of 76 sequences of variable amino acid compositions and lengths were synthesized as model compounds. In most cases, C-terminal amidated peptides were found to produce, upon CID, an abundant loss of ammonia from the protonated molecules. To validate such MS/MS signatures, the studied peptides contained amino acids that can potentially release ammonia from their side chains, such as asparagine, glutamine, tryptophan, lysine and arginine. Arginine, and to a lesser extent lysine, was shown to induce a competitive fragmentation leading to the loss of ammonia from their side chains, thus interfering with the targeted backbone neutral release. However, when arginine or lysine was located at the C-terminal position mimicking a tryptic digest, losses of ammonia from the arginine side chain and from the peptide backbone were completely suppressed. Such results were discussed in the frame of peptidomic or proteomic studies in an attempt to reveal the presence of C-terminal amidated peptides or proteins.

  6. 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.

  7. Joining of alumina ceramics and nickel alloy

    SciTech Connect

    Ariga, Tadashi; Nitta, Yuji; Miyazawa, Yasuyuki

    1994-12-31

    Joining of alumina ceramics to nickel alloy was made using the various types of Ag-Cu-Ti brazing filler metal. Ti-containing brazing filler metal was produced by physical vapor deposition (PVD) method on the joining area of the alumina ceramics. The joinability of the brazing filler metal was estimated by its mechanical properties. And the composition and structure of the ceramic-metal bond zone in the alumina ceramics-nickel alloy joints were analyzed by SEM, EPMA and X-ray diffraction examinations. Some of brazing filler metal achieved the highest shear strength 100 MPa at room temperature. The elemental distributions of the interface between alumina ceramics and Ag-Cu-Ti brazing filler metal was shown to form the reaction layer consisting titanium oxide.

  8. 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.

  9. Novel method for joining CFRP to aluminium

    NASA Astrophysics Data System (ADS)

    Möller, F.; Thomy, C.; Vollertsen, F.; Schiebel, P.; Hoffmeister, C.; Herrmann, A. S.

    The current state of the art in joining of carbon-fibre reinforced composites (CFRP) to metals such as aluminium is - for the case of aircraft structures, e.g.- riveting or bolting. However, to reduce structural weight and improve structural performance, integral, load-bearing aluminium-CFRP-structures are desirable. To produce such structures, a novel joint configuration together with an appropriate thermal, laser-based joining process is suggested by the authors. In this paper, the joint configuration (based on CFRP-Ti-aluminium joints) and the laser beam conduction welding process will be presented, and first specimens obtained will be discussed with respect to their properties. It will be shown that the novel approach is in principle suitable to produce load-bearing CFRP-aluminium structures.

  10. One-step dual purpose joining technique

    NASA Technical Reports Server (NTRS)

    Buckley, J. D.; Swaim, R. J.; Fox, R. L. (Inventor)

    1982-01-01

    This fastener used in induction heating is a wire screen basically of an eddy current carrying material such as carbon steel. Selected wires in the screen are copper, sheathed in an insulating material. The screen is placed between two sheets of thermoplastics. When inductively heated, the composite softens and flows around the apertures of the screen. After this heating and joining, the copper wires may be used to conduct electricity.

  11. Thin layer joining by gas adsorption

    NASA Astrophysics Data System (ADS)

    Taga, Yasunori; Fukumura, Toshio

    2014-10-01

    Attempt has been made to join borosilicate glass and cycloolefin (COP) polymer film by using gas adsorption method. After corona plasma treat, COP was exposed to (3-glycidoxypropyl) trimethoxysilane (GPS) and glass to (3-aminopropyl) triethoxysilane (APS) both in air atmosphere, resulting in co-adsorption of water vapor in the atmosphere and organosilane gases. Surface characterization of plasma treated and gas adsorbed surfaces was carried out by X-ray photoelectron spectroscopy (XPS) using Mg Kα X-ray source. Joining was carried out by a roll laminator after contact of both surfaces at room temperature, followed by annealing at 130 °C for 10 min. Adhesion strength was evaluated by 180 degree peel test based on ASTM D-903 and durability was examined under the conditions of 60 °C and 95% RH. It was found that after plasma treatment, complex functional groups such as Csbnd H, Csbnd O, Cdbnd O, Osbnd Cdbnd O and CO3 were found on COP and Osbnd H on glass. Thickness of GPS gas adsorption layer on COP was evaluated by the XPS to be at least 1.1 nm by taking inelastic mean free path of Si2p photoelectron into consideration. Joining force was found to be more than 5 N/25 mm corresponding to almost equal to COP bulk tensile strength. In addition, durability of this adhesion strength remained unchanged over 2000 h even after exposure to the durability test conditions of 60 °C and 95% RH. The results can be explained in terms of formation of Hsbnd H hydrogen bonding and Sisbnd O covalent bonding via silanols will be made at the interface as a result of lamination and annealing processes. In conclusion, ultrathin joining method by gas adsorption was established by the formation of hydrogen and covalent bonds at the interface by low temperature reaction process.

  12. Joining of materials using laser heating

    DOEpatents

    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.

  13. Flexible Hybrid Friction Stir Joining Technology

    SciTech Connect

    2008-12-01

    This factsheet describes a research project whose goal is to advance the friction stir welding (FSW) process as a manufacturing technology that can be deployed for on-site construction of large, complex and typically thick-sectioned structures made of high performance and high-temperature materials. This would transform FSW from a specialty joining process into one with pervasive application potential across a number of industrial sectors where the payoff of energy reduction, environmental and economic benefits would be significant.

  14. Conversion of amides to esters by the nickel-catalysed activation of amide C-N bonds

    NASA Astrophysics Data System (ADS)

    Hie, Liana; Fine Nathel, Noah F.; Shah, Tejas K.; Baker, Emma L.; Hong, Xin; Yang, Yun-Fang; Liu, Peng; Houk, K. N.; Garg, Neil K.

    2015-08-01

    Amides are common functional groups that have been studied for more than a century. They are the key building blocks of proteins and are present in a broad range of other natural and synthetic compounds. Amides are known to be poor electrophiles, which is typically attributed to the resonance stability of the amide bond. Although amides can readily be cleaved by enzymes such as proteases, it is difficult to selectively break the carbon-nitrogen bond of an amide using synthetic chemistry. Here we demonstrate that amide carbon-nitrogen bonds can be activated and cleaved using nickel catalysts. We use this methodology to convert amides to esters, which is a challenging and underdeveloped transformation. The reaction methodology proceeds under exceptionally mild reaction conditions, and avoids the use of a large excess of an alcohol nucleophile. Density functional theory calculations provide insight into the thermodynamics and catalytic cycle of the amide-to-ester transformation. Our results provide a way to harness amide functional groups as synthetic building blocks and are expected to lead to the further use of amides in the construction of carbon-heteroatom or carbon-carbon bonds using non-precious-metal catalysis.

  15. Joining of beta-SiC by spark plasma sintering

    SciTech Connect

    Grasso, Salvatore; Tatarko, Peter; Rizzo, S.; Porwal, Harshit; Hu, Chunfeng; Katoh, Yutai; Salvo, M; Reece, Michael John; Ferraris, Monica

    2014-01-01

    Spark plasma sintering (SPS) was employed to join monolithic -SiC with or without titanium as intermediate joining material. Both the localizedand rapid heating contributed to the inherent energy saving of electric current assisted joining technique. The effects of uniaxial pressure and surfacepreparation were analyzed independently with respect to the flexural strength and the morphology of the joints. In particular samples polisheddown to 1 m and joined at 1900 C for 5 min achieved the strength of the as received material. The failure occurred outside the joining interface,confirming the optimum quality of the joint. Pressure in combination with surface preparation was necessary to achieve perfect adhesion and porefree direct joining of SiC. The use of Ti foil as a joining material and pressure allowed joining of unpolished SiC.

  16. Astronaut Crippen prepares to join crew in training

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Astronaut Robert L. Crippen, 41-G crew commander, prepares to join his crew for training in the mockup and integration laboratory at JSC. Astronaut David C. Leestma, 41-G mission specialist, left, will join the crew in training.

  17. 40 CFR 721.10682 - Fatty acid amide hydrochlorides (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Fatty acid amide hydrochlorides... Specific Chemical Substances § 721.10682 Fatty acid amide hydrochlorides (generic). (a) Chemical substances... fatty acid amide hydrochlorides (PMNs P-13-63, P-13-64, P-13-65, P-13-69, P-13-70, P-13-71, P-13-72,...

  18. Oxidative activation of dihydropyridine amides to reactive acyl donors.

    PubMed

    Funder, Erik Daa; Trads, Julie B; Gothelf, Kurt V

    2015-01-07

    Amides of 1,4-dihydropyridine (DHP) are activated by oxidation for acyl transfer to amines, alcohols and thiols. In the reduced form the DHP amide is stable towards reaction with amines at room temperature. However, upon oxidation with DDQ the acyl donor is activated via a proposed pyridinium intermediate. The activated intermediate reacts with various nucleophiles to give amides, esters, and thio-esters in moderate to high yields.

  19. 46 CFR 56.75-30 - Pipe joining details.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) Copper-alloy brazing. (1) Copper-alloy brazing may be employed to join pipe, valves, and fittings... APPURTENANCES Brazing § 56.75-30 Pipe joining details. (a) Silver brazing. (1) Circumferential pipe joints may... satisfactory for the brazing alloy to be employed, method of heating, and material to be joined. The...

  20. 46 CFR 56.75-30 - Pipe joining details.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...) Copper-alloy brazing. (1) Copper-alloy brazing may be employed to join pipe, valves, and fittings... APPURTENANCES Brazing § 56.75-30 Pipe joining details. (a) Silver brazing. (1) Circumferential pipe joints may... satisfactory for the brazing alloy to be employed, method of heating, and material to be joined. The...

  1. 46 CFR 56.75-30 - Pipe joining details.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Pipe joining details. 56.75-30 Section 56.75-30 Shipping... APPURTENANCES Brazing § 56.75-30 Pipe joining details. (a) Silver brazing. (1) Circumferential pipe joints may be either of the socket or butt type. When butt joints are employed the edges to be joined shall...

  2. 24 CFR 17.62 - Subdivision and joining of claims.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Subdivision and joining of claims... General Provisions § 17.62 Subdivision and joining of claims. (a) A debtor's liability arising from a.... (b) Joining of two or more single claims in a demand upon a particular debtor for payment...

  3. 5 CFR 1201.36 - Consolidating and joining appeals.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 3 2012-01-01 2012-01-01 false Consolidating and joining appeals. 1201... § 1201.36 Consolidating and joining appeals. (a) Explanation. (1) Consolidation occurs when the appeals... example, a judge might join an appeal challenging a 30-day suspension with a pending appeal challenging...

  4. 24 CFR 17.62 - Subdivision and joining of claims.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 1 2011-04-01 2011-04-01 false Subdivision and joining of claims... General Provisions § 17.62 Subdivision and joining of claims. (a) A debtor's liability arising from a.... (b) Joining of two or more single claims in a demand upon a particular debtor for payment...

  5. 5 CFR 1201.36 - Consolidating and joining appeals.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 3 2011-01-01 2011-01-01 false Consolidating and joining appeals. 1201... § 1201.36 Consolidating and joining appeals. (a) Explanation. (1) Consolidation occurs when the appeals... example, a judge might join an appeal challenging a 30-day suspension with a pending appeal challenging...

  6. Electrochemical reduction of nitrate in the presence of an amide

    DOEpatents

    Dziewinski, Jacek J.; Marczak, Stanislaw

    2002-01-01

    The electrochemical reduction of nitrates in aqueous solutions thereof in the presence of amides to gaseous nitrogen (N.sub.2) is described. Generally, electrochemical reduction of NO.sub.3 proceeds stepwise, from NO.sub.3 to N.sub.2, and subsequently in several consecutive steps to ammonia (NH.sub.3) as a final product. Addition of at least one amide to the solution being electrolyzed suppresses ammonia generation, since suitable amides react with NO.sub.2 to generate N.sub.2. This permits nitrate reduction to gaseous nitrogen to proceed by electrolysis. Suitable amides include urea, sulfamic acid, formamide, and acetamide.

  7. Transport parameters in the human red cell membrane: solute-membrane interactions of amides and ureas.

    PubMed

    Toon, M R; Solomon, A K

    1991-04-02

    We have studied the permeability of a series of hydrophilic amides and ureas through the red cell membrane by determining the three phenomenological coefficients which describe solute-membrane interaction: the hydraulic permeability (Lp), the phenomenological permeability coefficient (omega i) and the reflection coefficient (sigma i). In 55 experiments on nine solutes, we have determined that the reflection coefficient (after a small correction for solute permeation by membrane dissolution) is significantly less than 1.0 (P less than 0.003, t-test), which provides very strong evidence that solute and water fluxes are coupled as they cross the red cell membrane. It is proposed that the aqueous channel is a tripartite assembly, comprising H-bond exchange regions at both faces of the membrane, joined by a narrower sieve-specific region which crosses the lipid. The solutes bind to the H-bond exchange regions to exchange their solvation shell with the H-bonds of the channel; the existence of these regions is confirmed by the finding that the permeation of all the amides and ureas requires binding to well-characterized sites with Km values of 0.1-0.5 M. The sieve-specific regions provide the steric restraints which govern the passage of the solutes according to their size; their existence is shown by the findings that: (1) the reflection coefficient (actually the function [1-corrected sigma i]) is linearly dependent upon the solute molecular diameter; and (2) the permeability coefficient is linearly dependent upon solute molar volume. These several observations, taken together, provide strong arguments which lead to the conclusion that the amides and urea cross the red cell membrane in an aqueous pore.

  8. METHOD OF JOINING CARBIDES TO BASE METALS

    DOEpatents

    Krikorian, N.H.; Farr, J.D.; Witteman, W.G.

    1962-02-13

    A method is described for joining a refractory metal carbide such as UC or ZrC to a refractory metal base such as Ta or Nb. The method comprises carburizing the surface of the metal base and then sintering the base and carbide at temperatures of about 2000 deg C in a non-oxidizing atmosphere, the base and carbide being held in contact during the sintering step. To reduce the sintering temperature and time, a sintering aid such as iron, nickel, or cobait is added to the carbide, not to exceed 5 wt%. (AEC)

  9. Thin shells joining local cosmic string geometries

    NASA Astrophysics Data System (ADS)

    Eiroa, Ernesto F.; Rubín de Celis, Emilio; Simeone, Claudio

    2016-10-01

    In this article we present a theoretical construction of spacetimes with a thin shell that joins two different local cosmic string geometries. We study two types of global manifolds, one representing spacetimes with a thin shell surrounding a cosmic string or an empty region with Minkowski metric, and the other corresponding to wormholes which are not symmetric across the throat located at the shell. We analyze the stability of the static configurations under perturbations preserving the cylindrical symmetry. For both types of geometries we find that the static configurations can be stable for suitable values of the parameters.

  10. SOLID STATE JOINING OF MAGNESIUM TO STEEL

    SciTech Connect

    Jana, Saumyadeep; Hovanski, Yuri; Pilli, Siva Prasad; Field, David P.; Yu, Hao; Pan, Tsung-Yu; Santella, M. L.

    2012-06-04

    Friction stir welding and ultrasonic welding techniques were applied to join automotive magnesium alloys to steel sheet. The effect of tooling and process parameters on the post-weld microstructure, texture and mechanical properties was investigated. Static and dynamic loading were utilized to investigate the joint strength of both cast and wrought magnesium alloys including their susceptibility and degradation under corrosive media. The conditions required to produce joint strengths in excess of 75% of the base metal strength were determined, and the effects of surface coatings, tooling and weld parameters on weld properties are presented.

  11. Joining of materials with engineered interlayers

    NASA Technical Reports Server (NTRS)

    Challenger, Kenneth D.; Cordea, Tom; Sengupta, Samit; Wampler, Scott

    1991-01-01

    A reliable method to join a variety of different materials is developed which uses engineered coatings to produce strong bonds by solid-state techniques at low temperatures (300-400 C). The strong bonds are capable of accommodating the strains created between Si and most substrates due to differences in thermal expansion coefficients. The approach encompasses two phases: noble metal compliant interlayers and functionally gradient interlayer bonding. Preliminary results are presented and the Ag interlayer bonds are microstructurally characterized confirming that the planar magnetron sputtered coatings/bonds are fully dense and metallurgically sound.

  12. Polymer Amide as an Early Topology

    PubMed Central

    McGeoch, Julie E. M.; McGeoch, Malcolm W.

    2014-01-01

    Hydrophobic polymer amide (HPA) could have been one of the first normal density materials to accrete in space. We present ab initio calculations of the energetics of amino acid polymerization via gas phase collisions. The initial hydrogen-bonded di-peptide is sufficiently stable to proceed in many cases via a transition state into a di-peptide with an associated bound water molecule of condensation. The energetics of polymerization are only favorable when the water remains bound. Further polymerization leads to a hydrophobic surface that is phase-separated from, but hydrogen bonded to, a small bulk water complex. The kinetics of the collision and subsequent polymerization are discussed for the low-density conditions of a molecular cloud. This polymer in the gas phase has the properties to make a topology, viz. hydrophobicity allowing phase separation from bulk water, capability to withstand large temperature ranges, versatility of form and charge separation. Its flexible tetrahedral carbon atoms that alternate with more rigid amide groups allow it to deform and reform in hazardous conditions and its density of hydrogen bonds provides adhesion that would support accretion to it of silicon and metal elements to form a stellar dust material. PMID:25048204

  13. Joining of thermoplastic substrates by microwaves

    DOEpatents

    Paulauskas, Felix L.; Meek, Thomas T.

    1997-01-01

    A method for joining two or more items having surfaces of thermoplastic material includes the steps of depositing an electrically-conductive material upon the thermoplastic surface of at least one of the items, and then placing the other of the two items adjacent the one item so that the deposited material is in intimate contact with the surfaces of both the one and the other items. The deposited material and the thermoplastic surfaces contacted thereby are then exposed to microwave radiation so that the thermoplastic surfaces in contact with the deposited material melt, and then pressure is applied to the two items so that the melted thermoplastic surfaces fuse to one another. Upon discontinuance of the exposure to the microwave energy, and after permitting the thermoplastic surfaces to cool from the melted condition, the two items are joined together by the fused thermoplastic surfaces. The deposited material has a thickness which is preferably no greater than a skin depth, .delta..sub.s, which is related to the frequency of the microwave radiation and characteristics of the deposited material in accordance with an equation.

  14. Joining Dental Ceramic Layers With Glass

    PubMed Central

    Saied, MA; Lloyd, IK; Haller, WK; Lawn, BR

    2011-01-01

    Objective Test the hypothesis that glass-bonding of free-form veneer and core ceramic layers can produce robust interfaces, chemically durable and aesthetic in appearance and, above all, resistant to delamination. Methods Layers of independently produced porcelains (NobelRondo™ Press porcelain, Nobel BioCare AB and Sagkura Interaction porcelain, Elephant Dental) and matching alumina or zirconia core ceramics (Procera alumina, Nobel BioCare AB, BioZyram yttria stabilized tetragonal zirconia polycrystal, Cyrtina Dental) were joined with designed glasses, tailored to match thermal expansion coefficients of the components and free of toxic elements. Scanning electron microprobe analysis was used to characterize the chemistry of the joined interfaces, specifically to confirm interdiffusion of ions. Vickers indentations were used to drive controlled corner cracks into the glass interlayers to evaluate the toughness of the interfaces. Results The glass-bonded interfaces were found to have robust integrity relative to interfaces fused without glass, or those fused with a resin-based adhesive. Significance The structural integrity of the interfaces between porcelain veneers and alumina or zirconia cores is a critical factor in the longevity of all-ceramic dental crowns and fixed dental prostheses. PMID:21802131

  15. Joining Composite Chassis Components on Heavy Trucks

    SciTech Connect

    Herling, Darrell R.; Klett, Lynn

    2003-09-27

    Class 8 trucks offer substantial opportunities for weight reduction with cost incentives resulting from increased payload and improved fuel efficiency. The chassis, suspension, drive train, and wheels contribute to approximately 40% of the truck weight and have components that are excellent candidates, in terms of material performance requirements, for replacement with low-density structural composite materials. However, actual or perceived deficiencies in joint reliability have, up to now, limited the use of polymer composites in this application. Researchers at Oak Ridge National Laboratory (ORNL) and Pacific Northwest National Laboratory (PNNL) have begun a project to overcome the major technical issues associated with joining thick fiber reinforced composite sections. The main objective is to develop both economical and robust attachment techniques for composite members joined to steel members. The research will be coordinated with an industry team led by Delphi Corporation that is developing and commercializing composite chassis members through funding from the Department of Energy's (DOE’s) High Strength Weight Reduction Materials Program, under the Office of FreedomCAR and Vehicle Technologies.

  16. Joining of Tungsten Armor Using Functional Gradients

    SciTech Connect

    John Scott O'Dell

    2006-12-31

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

  17. Fatty acid amides from freshwater green alga Rhizoclonium hieroglyphicum.

    PubMed

    Dembitsky, V M; Shkrob, I; Rozentsvet, O A

    2000-08-01

    Freshwater green algae Rhizoclonium hieroglyphicum growing in the Ural Mountains were examined for their fatty acid amides using capillary gas chromatography-mass spectrometry (GC-MS). Eight fatty acid amides were identified by GC-MS. (Z)-9-octadecenamide was found to be the major component (2.26%).

  18. Partition of compounds from water and from air into amides

    PubMed Central

    Acree, William E.; Cometto-Muñiz, J. Enrique

    2010-01-01

    Literature data on partitioning of compounds from the gas phase to a number of amides and from water to the amides has been collected and analyzed through the Abraham solvation equations. The resulting equations are statistically good enough to be used for the prediction of further partition coefficients, and allow deductions to be made about the chemical properties of the amides, as solvents. For example, tertiary amides have no hydrogen bond property at all, secondary amides are rather weak hydrogen bond acids, and primary amides are stronger hydrogen bond acids than are alcohols as solvents. Equations for partitioning from the gas phase to amide solvents can also be used to test if the amides are possible models for a number of biological phases and biological processes. It is shown that no organic solvent is a suitable model for phases such as blood, brain, muscle, liver, heart or kidney, but that a number of rather non-polar solvents are models for fat. N-methylformamide is shown to be the best (and excellent) model for eye irritation and nasal pungency in humans, suggesting that the receptor site in these processes is protein-like. PMID:20209022

  19. Cytotoxic Amides from Fruits of Kawakawa, Macropiper excelsum.

    PubMed

    Lei, Jeremy; Burgess, Elaine J; Richardson, Alistair T B; Hawkins, Bill C; Baird, Sarah K; Smallfield, Bruce M; van Klink, John W; Perry, Nigel B

    2015-08-01

    Cytotoxic amides have been isolated from the fruits of the endemic New Zealand medicinal plant kawakawa, Macropiper excelsum (Piperaceae). The main amide was piperchabamide A and this is the first report of this rare compound outside the genus Piper. Eleven other amides were purified including two new compounds with the unusual 3,4-dihydro-1(2H)-pyridinyl group. The new compounds were fully characterized by 2D NMR spectroscopy, which showed a slow exchange between two rotamers about the amide bond, and they were chemically synthesized. In view of the antitumor activity of the related piperlongumine, all of these amides plus four synthetic analogs were tested for cytotoxicity. The most active was the piperine homolog piperdardine, with an IC50 of 14 µM against HT 29 colon cancer cells.

  20. G. N. Rassam Joins AGU Staff

    NASA Astrophysics Data System (ADS)

    Ghassan N. Rassam joined the AGU staff today, assuming the dual roles of Division Director for Public Information and Marketing and of Special Assistant for Nonprint Publications. He comes to AGU from the American Geological Institute, where he has been chief editor and assistant director of the GeoRef Information System.As Director of Public Information and Marketing, Rassam will head one of AGU's five divisions. He will have under his purview the Public Information Department and the Promotion and Sales Department. The Public Information Department produces Eos and also has the responsibility for press relations, including the preparation of news releases and the operation of press rooms at meetings. These activities are critical to the implementation of AGU's public education and public affairs initiatives, as well as to the central role of AGU in promoting the unity of geophysics.

  1. Hydrogen production from ammonia using sodium amide.

    PubMed

    David, William I F; Makepeace, Joshua W; Callear, Samantha K; Hunter, Hazel M A; Taylor, James D; Wood, Thomas J; Jones, Martin O

    2014-09-24

    This paper presents a new type of process for the cracking of ammonia (NH3) that is an alternative to the use of rare or transition metal catalysts. Effecting the decomposition of NH3 using the concurrent stoichiometric decomposition and regeneration of sodium amide (NaNH2) via sodium metal (Na), this represents a significant departure in reaction mechanism compared with traditional surface catalysts. In variable-temperature NH3 decomposition experiments, using a simple flow reactor, the Na/NaNH2 system shows superior performance to supported nickel and ruthenium catalysts, reaching 99.2% decomposition efficiency with 0.5 g of NaNH2 in a 60 sccm NH3 flow at 530 °C. As an abundant and inexpensive material, the development of NaNH2-based NH3 cracking systems may promote the utilization of NH3 for sustainable energy storage purposes.

  2. 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.

  3. Research on microwave joining of SiC

    SciTech Connect

    1995-12-31

    The objectives of this research project are to identify optimum time-temperature profiles for the microwave joining of silicon carbide and to develop new microwave joining methods that can be applied to accomplish in situ formation of silicon carbide interlayers and to join larger samples required for industrial applications. Work during this reporting period was focused on investigation of the effect of specimen preparation on joining of SiC using polymer precursors to form SiC in situ at the interface. During this period, LANL also completed the evaluation of joints that were made by FMT using four different joining temperatures, as part of an effort to determine optimum joining temperature.

  4. Chemical attributes of some clouds amid a forest ecosystem's trees

    USGS Publications Warehouse

    DeFelice, Thomas P.

    2002-01-01

    Simultaneous physical and chemical characteristics of clouds amid and above the trees of a montane forest, located about 3.3 km southwest of Mt. Mitchell, NC, were collected between 13 and 22 June 1993. This paper summarizes the chemical characteristics of the cloud droplets amid the trees. The ionic composition and pH of the analyzed amid-canopy cloud water samples are generally consistent with those of previous above-canopy cloud water samples obtained at this site. Magnesium, sodium, and calcium are highly correlated to each other amid the canopy as compared to above the canopy. Above-canopy and amid-canopy cloud-only episodes, with concurrent event-averaged cloud water pH values at or below 3.1, generally contain more magnesium, sodium, and calcium in the amid-canopy cloud water samples compared to concurrent above-canopy cloud water samples. The observed chemical differences between the amid-canopy cloud and the above- canopy cloud suggest an unhealthier environment for the tree canopy when the cloud water traversing this site has a pH value at or below 3.1. The predominant ion deposition fluxes were calculated to provide preliminary data for studies designed to explicitly quantify how the chemical composition of cloud water affects tree health. ?? 2002 Elsevier Science B.V. All rights reserved.

  5. Holographic optical assembly and photopolymerized joining of planar microspheres.

    PubMed

    Shaw, L A; Chizari, S; Panas, R M; Shusteff, M; Spadaccini, C M; Hopkins, J B

    2016-08-01

    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. This technique and our demonstrated joining approach enable HOT technology to take critical steps toward automated additive fabrication of microstructures.

  6. A NEW APPROACH TO JOINING SIC/SIC COMPOSITES

    SciTech Connect

    Henager, Charles H.

    2004-06-30

    A new approach to joining SiC-based ceramics is described and evaluated for Fusion Energy systems. The joining method is based on pre-ceramic polymers filled with reactive and inert filler powders and is similar to other approaches that use such materials. This approach differs in the particular polymer system and in the details of the processing. A principal advantage of this approach relative to other, similar approaches is that the polymer system is easily handled in ambient air and can be processed in air. This makes the joining process simple and field repairable. The joining compound is a liquid that can be painted, sprayed, or applied by dip coating.

  7. New organic semiconductors with imide/amide-containing molecular systems.

    PubMed

    Liu, Zitong; Zhang, Guanxin; Cai, Zhengxu; Chen, Xin; Luo, Hewei; Li, Yonghai; Wang, Jianguo; Zhang, Deqing

    2014-10-29

    Due to their high electron affinities, chemical and thermal stabilities, π-conjugated molecules with imide/amide frameworks have received considerable attentions as promising candidates for high-performance optoelectronic materials, particularly for organic semiconductors with high carrier mobilities. The purpose of this Research News is to give an overview of recent advances in development of high performance imide/amide based organic semiconductors for field-effect transistors. It covers naphthalene diimide-, perylene diimide- and amide-based conjugated molecules and polymers for organic semiconductors.

  8. UK Announces Intention to Join ESO

    NASA Astrophysics Data System (ADS)

    2000-11-01

    Summary The Particle Physics and Astronomy Research Council (PPARC) , the UK's strategic science investment agency, today announced that the government of the United Kingdom is making funds available that provide a baseline for this country to join the European Southern Observatory (ESO) . The ESO Director General, Dr. Catherine Cesarsky , and the ESO Community warmly welcome this move towards fuller integration in European astronomy. "With the UK as a potential member country of ESO, our joint opportunities for front-line research and technology will grow significantly", she said. "This announcement is a clear sign of confidence in ESO's abilities, most recently demonstrated with the construction and operation of the unique Very Large Telescope (VLT) on Paranal. Together we will look forward with confidence towards new, exciting projects in ground-based astronomy." It was decided earlier this year to place the 4-m UK Visible and Infrared Survey Telescope (VISTA) at Paranal, cf. ESO Press Release 03/00. Following negotiations between ESO and PPARC, a detailed proposal for the associated UK/ESO Agreement with the various entry modalities will now be presented to the ESO Council for approval. Before this Agreement can enter into force, the ESO Convention and associated protocols must also be ratified by the UK Parliament. Research and key technologies According to the PPARC press release, increased funding for science, announced by the UK government today, will enable UK astronomers to prepare for the next generation of telescopes and expand their current telescope portfolio through membership of the European Southern Observatory (ESO). The uplift to its baseline budget will enable PPARC to enter into final negotiations for UK membership of the ESO. This will ensure that UK astronomers, together with their colleagues in the ESO member states, are actively involved in global scale preparations for the next generation of astronomy facilities. among these are ALMA

  9. Austria Declares Intent To Join ESO

    NASA Astrophysics Data System (ADS)

    2008-04-01

    At a press conference today at the University of Vienna's Observatory, the Austrian Science Minister Johannes Hahn announced the decision by the Austrian Government to seek membership of ESO from 1 July this year. ESO PR Photo 11/08 ESO PR Photo 11/08 Announcing Austria's Intent to Join ESO Said Minister Hahn: "With membership of ESO, Austria's scientists will receive direct access to the world's leading infrastructure in astronomy. This strengthens Austria as a place for research and provides an opportunity for young researchers to continue their work from here. With this move, Austria takes an important step in the reinforcement of Europe's science and research infrastructure." The decision constitutes a major breakthrough for Austrian scientists who have argued for membership of ESO for many years. Seeking membership in ESO also marks a step towards the further development of the European Research and Innovation Area, an important element of Europe's so-called Lisbon Strategy. "ESO welcomes the Austrian bid to join our organisation. I salute the Austrian Government for taking this important step and look forward to working closely with our Austrian friends and colleagues in the years to come," commented the ESO Director General, Tim de Zeeuw. For Austrian astronomers, ESO membership means not only unrestricted access to ESO's world-leading observational facilities including the world's most advanced optical telescope, the Very Large Telescope, and full participation in the quasi-global ALMA project, but also the possibility to participate on a par with their European colleagues in the future projects of ESO, including the realisation of ESO's Extremely Large Telescope project (E-ELT), which is currently in the design phase. All these projects require some of the most advanced technologies in key areas such as optics, detectors, lightweight structures, etc. Austrian participation in ESO opens the door for Austrian industry and major research institutes of the

  10. End Joining at Caenorhabditis elegans Telomeres

    PubMed Central

    Lowden, Mia Rochelle; Meier, Bettina; Lee, Teresa Wei-sy; Hall, Julie; Ahmed, Shawn

    2008-01-01

    Critically shortened telomeres can be subjected to DNA repair events that generate end-to-end chromosome fusions. The resulting dicentric chromosomes can enter breakage–fusion–bridge cycles, thereby impeding elucidation of the structures of the initial fusion events and a mechanistic understanding of their genesis. Current models for the molecular basis of fusion of critically shortened, uncapped telomeres rely on PCR assays that typically capture fusion breakpoints created by direct ligation of chromosome ends. Here we use independent approaches that rely on distinctive features of Caenorhabditis elegans to study the frequency of direct end-to-end chromosome fusion in telomerase mutants: (1) holocentric chromosomes that allow for genetic isolation of stable end-to-end fusions and (2) unique subtelomeric sequences that allow for thorough PCR analysis of samples of genomic DNA harboring multiple end-to-end fusions. Surprisingly, only a minority of end-to-end fusion events resulted from direct end joining with no additional genome rearrangements. We also demonstrate that deficiency for the C. elegans Ku DNA repair heterodimer does not affect telomere length or cause synthetic effects in the absence of telomerase. PMID:18780750

  11. MICROBIAL DEGRADATION OF SEVEN AMIDES BY SUSPENDED BACTERIAL POPULATIONS

    EPA Science Inventory

    Microbial transformation rate constants were determined for seven amides in natural pond water. A second-order mathematical rate expression served as the model for describing the microbial transformation. Also investigated was the relationship between the infrared spectra and the...

  12. Synthesis, HPLC measurement and bioavailability of the phenolic amide amkamide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Amkamide, oretamide, becatamide, enferamide and veskamide are phenolic amides whose analogues are found in plants. Recently, becatamide was reported to have very potent mitochondria protective activity. In this study, becatamide and analogues (amkamide, oretamide, enferamide and veskamide) were chem...

  13. Silver-catalyzed synthesis of amides from amines and aldehydes

    DOEpatents

    Madix, Robert J; Zhou, Ling; Xu, Bingjun; Friend, Cynthia M; Freyschlag, Cassandra G

    2014-11-18

    The invention provides a method for producing amides via the reaction of aldehydes and amines with oxygen adsorbed on a metallic silver or silver alloy catalyst. An exemplary reaction is shown in Scheme 1: (I), (II), (III). ##STR00001##

  14. Alkyl amides and nitriles as novel tracers for biomass burning.

    PubMed

    Rushdi, A I; bin Abas, M R; Didyk, B M

    2003-01-01

    The occurrence of n-alkanoic acids, amides, and nitriles in samples of aerosol particulate matter from Kuala Lumpur and Santiago suggests that emissions from cooking and biomass burning are the primary sources of these organic markers in the atmosphere. It is proposed that fatty acids react with ammonia during biomass burning or combustion to produce amides and nitriles, which can be applied as useful biomarker tracers. To test this hypothesis, nonadecanoic acid and hexadecanamide were used as reactants in hydrous pyrolysis experiments. These experiments produced amides and nitriles and indicated that ammonia is an essential agent in their formation. Thus amides and nitriles are of utility as indicators for input from combustion and biomass burning in the ambient atmosphere.

  15. Method of joining metals of significantly different expansion rates

    NASA Technical Reports Server (NTRS)

    Caler, W.; La Salle, F.; Traylor, J.

    1971-01-01

    To join a refractory metal to a dissimilar high-temperature metal, braze a section of high elasticity, high ductility metal /such as columbium or columbium alloy/ between the metals to be joined, using a fork-type joint to hold the braze and transition member in place during expansion.

  16. 49 CFR 192.283 - Plastic pipe: Qualifying joining procedures.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Plastic pipe: Qualifying joining procedures. 192... 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...

  17. 49 CFR 192.283 - Plastic pipe: Qualifying joining procedures.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Plastic pipe: Qualifying joining procedures. 192... 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...

  18. 49 CFR 192.283 - Plastic pipe: Qualifying joining procedures.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Plastic pipe: Qualifying joining procedures. 192... 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...

  19. 49 CFR 192.283 - Plastic pipe: Qualifying joining procedures.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Plastic pipe: Qualifying joining procedures. 192... 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...

  20. 49 CFR 192.283 - Plastic pipe: Qualifying joining procedures.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Plastic pipe: Qualifying joining procedures. 192... 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...

  1. 46 CFR 56.75-30 - Pipe joining details.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...) Copper-alloy brazing. (1) Copper-alloy brazing may be employed to join pipe, valves, and fittings... satisfactory for the brazing alloy to be employed, method of heating, and material to be joined. The annular... in place until the brazing alloy has set so as to prevent any strain on the joint until the...

  2. 46 CFR 56.75-30 - Pipe joining details.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...) Copper-alloy brazing. (1) Copper-alloy brazing may be employed to join pipe, valves, and fittings... satisfactory for the brazing alloy to be employed, method of heating, and material to be joined. The annular... in place until the brazing alloy has set so as to prevent any strain on the joint until the...

  3. A novel method for heterocyclic amide-thioamide transformations.

    PubMed

    Fathalla, Walid; Ali, Ibrahim A I; Pazdera, Pavel

    2017-01-01

    In this paper, we introduce a novel and convenient method for the transformation of heterocyclic amides into heteocyclic thioamides. A two-step approach was applied for this transformation: Firstly, we applied a chlorination of the heterocyclic amides to afford the corresponding chloroheterocycles. Secondly, the chloroherocycles and N-cyclohexyl dithiocarbamate cyclohexylammonium salt were heated in chloroform for 12 h at 61 °C to afford heteocyclic thioamides in excellent yields.

  4. Highly Stereoselective Intermolecular Haloetherification and Haloesterification of Allyl Amides

    PubMed Central

    Soltanzadeh, Bardia; Jaganathan, Arvind; Staples, Richard J.

    2016-01-01

    An organocatalytic and highly regio-, diastereo-, and enantioselective intermolecular haloetherification and haloesterification reaction of allyl amides is reported. A variety of alkene substituents and substitution patterns are compatible with this chemistry. Notably, electronically unbiased alkene substrates exhibit exquisite regio- and diastereoselectivity for the title transformation. We also demonstrate that the same catalytic system can be used in both chlorination and bromination reactions of allyl amides with a variety of nucleophiles with little or no modification. PMID:26110812

  5. Insecticidal, Repellent and Fungicidal Properties of Novel Trifluoromethylphenyl Amides

    DTIC Science & Technology

    2013-01-01

    fungi Trifluoromethylphenyl amides Aedes aegypti Anopheles albimanus Drosophila melanogaster a b s t r a c t Twenty trifluoromethylphenyl amides were...larvae and adults were significantly lower: 13.55 nM and 0.787 104 nM, respectively. Compound 1c was also active against Drosophila melanogaster ...Selected compounds were evaluated for toxicity against Drosophila melanogaster . 2. Materials and methods 2.1. Synthesis of trifluoromethylphenyl

  6. Recent Developments in Amide Synthesis Using Nonactivated Starting Materials.

    PubMed

    Ojeda-Porras, Andrea; Gamba-Sánchez, Diego

    2016-12-02

    Amides are unquestionably one of the most important functional groups in organic chemistry because of their presence in numerous interesting molecules such as peptides, pharmaceutical agents, naturally occurring molecules, proteins and alkaloids, among others. This synopsis surveys the diverse recent approaches to amide synthesis from nonactivated carboxylic acids and derivatives as well as noncarboxylic compounds, highlighting the most innovative methodologies and those that are more eco-friendly compared to traditional methods while focusing on recent developments during the past two years.

  7. 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.

  8. Rapid infrared joining takes on the advanced materials

    NASA Astrophysics Data System (ADS)

    Blue, C. A.; Warrier, S. G.; Robson, M. T.; Lin, R. Y.

    1993-06-01

    In this work, 4340 steel was joined with a nickel-based brazing alloy AMS 4777, using rapid infrared joining technique (Blue et al., 1991), and the microstructure of the joint was examined using SEM. The effects of the bond thickness and the joint lap area on the bond shear strength were investigated following the ASTM D1002-72 standard joint testing procedure. Results of SEM examination indicated that the microstructure of the material was preserved throughout the joining process. Bond shear tests showed that, as the bond thickness increases, the shear strength also increases, reaching a constant bond strength plateau at about 2 mils. It is concluded that, compared with traditional joining methods, the rapid infrared joining technique has the advantages of fast heating, little energy consumption, easy operation, no need for vacuum, little metallurgical modification to the base metal, and low cost.

  9. Finite Element Modeling and Optimization of Mechanical Joining Technology

    NASA Astrophysics Data System (ADS)

    Chenot, Jean-Loup; Bouchard, Pierre-Olivier; Massoni, Elisabeth; Mocellin, Katia; Lasne, Patrice

    2011-05-01

    The main scientific ingredients are recalled for developing a general finite element code and model accurately large plastic deformation of metallic materials during joining processes. Multi material contact is treated using the classical master and slave approach. Rupture may occur in joining processes or even be imposed in self piercing riveting and it must be predicted to evaluate the ultimate strength of joins. Damage is introduced with a generalized uncoupled damage criterion, or by utilizing a coupled formulation with a Lemaître law. Several joining processes are briefly analyzed in term of specific scientific issues: riveting, self piercing riveting, clinching, crimping, hemming and screwing. It is shown that not only the joining process can be successfully simulated and optimized, but also the strength of the assembly can be predicted in tension and in shearing.

  10. Affordable, Robust Ceramic Joining Technology (ARCJoinT)

    NASA Technical Reports Server (NTRS)

    Singh, M.

    1998-01-01

    Joining is recognized as one of the enabling technologies for the application of silicon carbide-based ceramic and 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. These joints maintain their mechanical strength up to 1350 C in air. 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 ceramic components damaged in service.

  11. Hydrogen Bonding Interaction between Atmospheric Gaseous Amides and Methanol

    PubMed Central

    Zhao, Hailiang; Tang, Shanshan; Xu, Xiang; Du, Lin

    2016-01-01

    Amides are important atmospheric organic–nitrogen compounds. Hydrogen bonded complexes of methanol (MeOH) with amides (formamide, N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide and N,N-dimethylacetamide) have been investigated. The carbonyl oxygen of the amides behaves as a hydrogen bond acceptor and the NH group of the amides acts as a hydrogen bond donor. The dominant hydrogen bonding interaction occurs between the carbonyl oxygen and the OH group of methanol as well as the interaction between the NH group of amides and the oxygen of methanol. However, the hydrogen bonds between the CH group and the carbonyl oxygen or the oxygen of methanol are also important for the overall stability of the complexes. Comparable red shifts of the C=O, NH- and OH-stretching transitions were found in these MeOH–amide complexes with considerable intensity enhancement. Topological analysis shows that the electron density at the bond critical points of the complexes fall in the range of hydrogen bonding criteria, and the Laplacian of charge density of the O–H∙∙∙O hydrogen bond slightly exceeds the upper value of the Laplacian criteria. The energy decomposition analysis further suggests that the hydrogen bonding interaction energies can be mainly attributed to the electrostatic, exchange and dispersion components. PMID:28042825

  12. Brazil to Join the European Southern Observatory

    NASA Astrophysics Data System (ADS)

    2010-12-01

    The Federative Republic of Brazil has yesterday signed the formal accession agreement paving the way for it to become a Member State of the European Southern Observatory (ESO). Following government ratification Brazil will become the fifteenth Member State and the first from outside Europe. On 29 December 2010, at a ceremony in Brasilia, the Brazilian Minister of Science and Technology, Sergio Machado Rezende and the ESO Director General, Tim de Zeeuw signed the formal accession agreement aiming to make Brazil a Member State of the European Southern Observatory. Brazil will become the fifteen Member State and the first from outside Europe. Since the agreement means accession to an international convention, the agreement must now be submitted to the Brazilian Parliament for ratification [1]. The signing of the agreement followed the unanimous approval by the ESO Council during an extraordinary meeting on 21 December 2010. "Joining ESO will give new impetus to the development of science, technology and innovation in Brazil as part of the considerable efforts our government is making to keep the country advancing in these strategic areas," says Rezende. The European Southern Observatory has a long history of successful involvement with South America, ever since Chile was selected as the best site for its observatories in 1963. Until now, however, no non-European country has joined ESO as a Member State. "The membership of Brazil will give the vibrant Brazilian astronomical community full access to the most productive observatory in the world and open up opportunities for Brazilian high-tech industry to contribute to the European Extremely Large Telescope project. It will also bring new resources and skills to the organisation at the right time for them to make a major contribution to this exciting project," adds ESO Director General, Tim de Zeeuw. The European Extremely Large Telescope (E-ELT) telescope design phase was recently completed and a major review was

  13. Modeling Non-homologous End Joining

    NASA Technical Reports Server (NTRS)

    Li, Yongfeng

    2013-01-01

    Non-homologous end joining (NHEJ) is the dominant DNA double strand break (DSB) repair pathway and involves several NHEJ proteins such as Ku, DNA-PKcs, XRCC4, Ligase IV and so on. Once DSBs are generated, Ku is first recruited to the DNA end, followed by other NHEJ proteins for DNA end processing and ligation. Because of the direct ligation of break ends without the need for a homologous template, NHEJ turns out to be an error-prone but efficient repair pathway. Some mechanisms have been proposed of how the efficiency of NHEJ repair is affected. The type of DNA damage is an important factor of NHEJ repair. For instance, the length of DNA fragment may determine the recruitment efficiency of NHEJ protein such as Ku [1], or the complexity of the DNA breaks [2] is accounted for the choice of NHEJ proteins and subpathway of NHEJ repair. On the other hand, the chromatin structure also plays a role of the accessibility of NHEJ protein to the DNA damage site. In this talk, some mathematical models of NHEJ, that consist of series of biochemical reactions complying with the laws of chemical reaction (e.g. mass action, etc.), will be introduced. By mathematical and numerical analysis and parameter estimation, the models are able to capture the qualitative biological features and show good agreement with experimental data. As conclusions, from the viewpoint of modeling, how the NHEJ proteins are recruited will be first discussed for connection between the classical sequential model [4] and recently proposed two-phase model [5]. Then how the NHEJ repair pathway is affected, by the length of DNA fragment [6], the complexity of DNA damage [7] and the chromatin structure [8], will be addressed

  14. Nonplanar tertiary amides in rigid chiral tricyclic dilactams. Peptide group distortions and vibrational optical activity.

    PubMed

    Pazderková, Markéta; Profant, Václav; Hodačová, Jana; Sebestík, Jaroslav; Pazderka, Tomáš; Novotná, Pavlína; Urbanová, Marie; Safařík, Martin; Buděšínský, Miloš; Tichý, Miloš; Bednárová, Lucie; Baumruk, Vladimír; Maloň, Petr

    2013-08-22

    We investigate amide nonplanarity in vibrational optical activity (VOA) spectra of tricyclic spirodilactams 5,8-diazatricyclo[6,3,0,0(1,5)]undecan-4,9-dione (I) and its 6,6',7,7'-tetradeuterio derivative (II). These rigid molecules constrain amide groups to nonplanar geometries with twisted pyramidal arrangements of bonds to amide nitrogen atoms. We have collected a full range vibrational circular dichroism (VCD) and Raman optical activity (ROA) spectra including signals of C-H and C-D stretching vibrations. We report normal-mode analysis and a comparison of calculated to experimental VCD and ROA. The data provide band-to-band assignment and offer a possibility to evaluate roles of constrained nonplanar tertiary amide groups and rigid chiral skeletons. Nonplanarity shows as single-signed VCD and ROA amide I signals, prevailing the couplets expected to arise from the amide-amide interaction. Amide-amide coupling dominates amide II (mainly C'-N stretching, modified in tertiary amides by the absence of a N-H bond) transitions (strong couplet in VCD, no significant ROA) probably due to the close proximity of amide nitrogen atoms. At lower wavenumbers, ROA spectra exhibit another likely manifestation of amide nonplanarity, showing signals of amide V (δ(oop)(N-C) at ~570 cm(-1)) and amide VI (δ(oop)(C'═O) at ~700 cm(-1) and ~650 cm(-1)) vibrations.

  15. Selective Formation of Secondary Amides via the Copper-Catalyzed Cross-Coupling of Alkylboronic Acids with Primary Amides

    PubMed Central

    Rossi, Steven A.; Shimkin, Kirk W.; Xu, Qun; Mori-Quiroz, Luis M.; Watson, Donald A.

    2014-01-01

    For the first time, a general catalytic procedure for the cross coupling of primary amides and alkylboronic acids is demonstrated. The key to the success of this reaction was the identification of a mild base (NaOSiMe3) and oxidant (di-tert-butyl peroxide) to promote the copper-catalyzed reaction in high yield. This transformation provides a facile, high-yielding method for the mono-alkylation of amides. PMID:23611591

  16. The spatial organization of non-homologous end joining: from bridging to end joining.

    PubMed

    Ochi, Takashi; Wu, Qian; Blundell, Tom L

    2014-05-01

    Non-homologous end joining (NHEJ) repairs DNA double-strand breaks generated by DNA damage and also those occurring in V(D)J recombination in immunoglobulin and T cell receptor production in the immune system. In NHEJ DNA-PKcs assembles with Ku heterodimer on the DNA ends at double-strand breaks, in order to bring the broken ends together and to assemble other proteins, including DNA ligase IV (LigIV), required for DNA repair. Here we focus on structural aspects of the interactions of LigIV with XRCC4, XLF, Artemis and DNA involved in the bridging and end-joining steps of NHEJ. We begin with a discussion of the role of XLF, which interacts with Ku and forms a hetero-filament with XRCC4; this likely forms a scaffold bridging the DNA ends. We then review the well-defined interaction of XRCC4 with LigIV, and discuss the possibility of this complex interrupting the filament formation, so positioning the ligase at the correct positions close to the broken ends. We also describe the interactions of LigIV with Artemis, the nuclease that prepares the ends for ligation and also interacts with DNA-PK. Lastly we review the likely affects of Mendelian mutations on these multiprotein assemblies and their impacts on the form of inherited disease.

  17. The spatial organization of non-homologous end joining: From bridging to end joining

    PubMed Central

    Ochi, Takashi; Wu, Qian; Blundell, Tom L.

    2014-01-01

    Non-homologous end joining (NHEJ) repairs DNA double-strand breaks generated by DNA damage and also those occurring in V(D)J recombination in immunoglobulin and T cell receptor production in the immune system. In NHEJ DNA-PKcs assembles with Ku heterodimer on the DNA ends at double-strand breaks, in order to bring the broken ends together and to assemble other proteins, including DNA ligase IV (LigIV), required for DNA repair. Here we focus on structural aspects of the interactions of LigIV with XRCC4, XLF, Artemis and DNA involved in the bridging and end-joining steps of NHEJ. We begin with a discussion of the role of XLF, which interacts with Ku and forms a hetero-filament with XRCC4; this likely forms a scaffold bridging the DNA ends. We then review the well-defined interaction of XRCC4 with LigIV, and discuss the possibility of this complex interrupting the filament formation, so positioning the ligase at the correct positions close to the broken ends. We also describe the interactions of LigIV with Artemis, the nuclease that prepares the ends for ligation and also interacts with DNA-PK. Lastly we review the likely affects of Mendelian mutations on these multiprotein assemblies and their impacts on the form of inherited disease. PMID:24636752

  18. Solid State Joining of Dissimilar Titanium Alloys

    NASA Astrophysics Data System (ADS)

    Morton, Todd W.

    Solid state joining of titanium via friction stir welding and diffusion bonding have emerged as enablers of efficient monolithic structural designs by the eliminations fasteners for the aerospace industry. As design complexity and service demands increase, the need for joints of dissimilar alloys has emerged. Complex thermomechanical conditions in friction stir weld joints and high temperature deformation behavior differences between alloys used in dissimilar joints gives rise to a highly variable flow pattern within a stir zone. Experiments performed welding Ti-6Al-4V to beta21S show that mechanical intermixing of the two alloys is the primary mechanism for the generation of the localized chemistry and microstructure, the magnitude of which can be directly related to pin rotation and travel speed weld parameters. Mechanical mixing of the two alloys is heavily influenced by strain rate softening phenomena, and can be used to manipulate weld nugget structure by switching which alloy is subjected to the advancing side of the pin. Turbulent mixing of a weld nugget and a significant reduction in defects and weld forces are observed when the beta21S is put on the advancing side of the weld where higher strain rates are present. Chemical diffusion driven by the heat of weld parameters is characterized using energy dispersive x-ray spectroscopy (EDS) and is shown to be a secondary process responsible for generating short-range chemical gradients that lead to a gradient of alpha particle structures. Diffusion calculations are inconsistent with an assumption of steady-state diffusion and show that material interfaces in the weld nugget evolve through the break-down of turbulent interface features generated by material flows. A high degree of recrystallization is seen throughout the welds, with unique, hybrid chemistry grains that are generated at material interfaces in the weld nugget that help to unify the crystal structure of dissimilar alloys. The degree of

  19. Phenolic amides are potent inhibitors of De Novo nucleotide biosynthesis

    DOE PAGES

    Pisithkul, Tippapha; Jacobson, Tyler B.; O'Brien, Thomas J.; ...

    2015-06-12

    An outstanding challenge toward efficient production of biofuels and value-added chemicals from plant biomass is the impact that lignocellulose-derived inhibitors have on microbial fermentations. Elucidating the mechanisms that underlie their toxicity is critical for developing strategies to overcome them. Here, using Escherichia coli as a model system, we investigated the metabolic effects and toxicity mechanisms of feruloyl amide and coumaroyl amide, the predominant phenolic compounds in ammonia-pretreated biomass hydrolysates. Using metabolomics, isotope tracers, and biochemical assays, we showed that these two phenolic amides act as potent and fast-acting inhibitors of purine and pyrimidine biosynthetic pathways. Feruloyl or coumaroyl amide exposuremore » leads to (i) a rapid buildup of 5-phosphoribosyl-1-pyrophosphate (PRPP), a key precursor in nucleotide biosynthesis, (ii) a rapid decrease in the levels of pyrimidine biosynthetic intermediates, and (iii) a long-term generalized decrease in nucleotide and deoxynucleotide levels. Tracer experiments using 13C-labeled sugars and [15N]ammonia demonstrated that carbon and nitrogen fluxes into nucleotides and deoxynucleotides are inhibited by these phenolic amides. We found that these effects are mediated via direct inhibition of glutamine amidotransferases that participate in nucleotide biosynthetic pathways. In particular, feruloyl amide is a competitive inhibitor of glutamine PRPP amidotransferase (PurF), which catalyzes the first committed step in de novo purine biosynthesis. Finally, external nucleoside supplementation prevents phenolic amide-mediated growth inhibition by allowing nucleotide biosynthesis via salvage pathways. Furthermore, the results presented here will help in the development of strategies to overcome toxicity of phenolic compounds and facilitate engineering of more efficient microbial producers of biofuels and chemicals.« less

  20. Phenolic Amides Are Potent Inhibitors of De Novo Nucleotide Biosynthesis

    PubMed Central

    Pisithkul, Tippapha; Jacobson, Tyler B.; O'Brien, Thomas J.; Stevenson, David M.

    2015-01-01

    An outstanding challenge toward efficient production of biofuels and value-added chemicals from plant biomass is the impact that lignocellulose-derived inhibitors have on microbial fermentations. Elucidating the mechanisms that underlie their toxicity is critical for developing strategies to overcome them. Here, using Escherichia coli as a model system, we investigated the metabolic effects and toxicity mechanisms of feruloyl amide and coumaroyl amide, the predominant phenolic compounds in ammonia-pretreated biomass hydrolysates. Using metabolomics, isotope tracers, and biochemical assays, we showed that these two phenolic amides act as potent and fast-acting inhibitors of purine and pyrimidine biosynthetic pathways. Feruloyl or coumaroyl amide exposure leads to (i) a rapid buildup of 5-phosphoribosyl-1-pyrophosphate (PRPP), a key precursor in nucleotide biosynthesis, (ii) a rapid decrease in the levels of pyrimidine biosynthetic intermediates, and (iii) a long-term generalized decrease in nucleotide and deoxynucleotide levels. Tracer experiments using 13C-labeled sugars and [15N]ammonia demonstrated that carbon and nitrogen fluxes into nucleotides and deoxynucleotides are inhibited by these phenolic amides. We found that these effects are mediated via direct inhibition of glutamine amidotransferases that participate in nucleotide biosynthetic pathways. In particular, feruloyl amide is a competitive inhibitor of glutamine PRPP amidotransferase (PurF), which catalyzes the first committed step in de novo purine biosynthesis. Finally, external nucleoside supplementation prevents phenolic amide-mediated growth inhibition by allowing nucleotide biosynthesis via salvage pathways. The results presented here will help in the development of strategies to overcome toxicity of phenolic compounds and facilitate engineering of more efficient microbial producers of biofuels and chemicals. PMID:26070680

  1. Joining of parts via magnetic heating of metal aluminum powders

    SciTech Connect

    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.

  2. Joining SI3N4 for Advanced Turbomachinery Applications

    SciTech Connect

    GLASS, S. JILL; LOEHMAN, RONALD E.; HOSKING, F. MICHAEL; STEPHENS JR., JOHN J.; VIANCO, PAUL T.; NEILSEN, MICHAEL K.; WALKER, CHARLES A.; POLLINGER, J.P.; MAHONEY, F.M.; QUILLEN, B.G.

    2000-07-01

    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 the stresses in the ceramic regions of ceramic-to-metal joints sleeve and butt joints, similar to the geometries used for stator assemblies.

  3. Microwave joining of SiC ceramics and composites

    SciTech Connect

    Ahmad, I.; Silberglitt, R.; Tian, Y.L.; Katz, J.D.

    1997-04-01

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

  4. 10. EYEBAR PIN CONNECTION JOINING VERTICAL SUSPENSION STRINGER WITH LATERAL ...

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

    10. EYEBAR PIN CONNECTION JOINING VERTICAL SUSPENSION STRINGER WITH LATERAL BRACING MEMBERS - Spruce Street Bridge, East Spruce Street, 500 Block, spanning Power Canal, Sault Ste. Marie, Chippewa County, MI

  5. Holographic optical assembly and photopolymerized joining of planar microspheres

    SciTech Connect

    Shaw, L. A.; Chizari, S.; Panas, R. M.; Shusteff, M.; Spadaccini, C. M.; Hopkins, J. B.

    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 enable HOT technology to take critical steps toward automated additive fabrication of microstructures.

  6. Join NASA: The Sky is NOT the Limit

    NASA Video Gallery

    We're going to send humans farther into space than ever before ... and eventually to Mars. We need YOU to help plan for this future of exploration. Join NASA: Get your application in now for the 20...

  7. 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.

  8. Holographic optical assembly and photopolymerized joining of planar microspheres

    DOE PAGES

    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

  9. 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.

  10. Who Should Join the Environmental Response Laboratory Network

    EPA Pesticide Factsheets

    Laboratories that analyze biological samples, chemical warfare agents, radiological, or toxic industrial chemical samples can join the ERLN. Members make up a critical infrastructure that delivers data necessary for responses to large scale emergencies.

  11. Chord Splicing & Joining Detail; Chord & CrossBracing Joint Details; ...

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

    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

  12. TRANSFORMER FOR JOINING UNBALANCED TO BALANCED TRANSMISSION MEANS

    DOEpatents

    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.

  13. South Pole Telescope joins black-hole project

    NASA Astrophysics Data System (ADS)

    Allen, Michael

    2015-06-01

    Astronomers are one step closer to observing the event horizon of a black hole after Antarctica's largest telescope joined a worldwide collection of millimetre/submillimetre facilities pursuing this goal.

  14. Little Brother Joins the Large Family

    NASA Astrophysics Data System (ADS)

    2006-12-01

    On the night of 15 December 2006, the fourth and last-to-be-installed VLTI Auxiliary Telescope (AT4) obtained its 'First Light'. The first images demonstrate that AT4 will be able to deliver the excellent image quality already delivered by the first three ATs. It will soon join its siblings to perform routinely interferometric measurements. ESO PR Photo 51a/06 ESO PR Photo 51a/06 VLT Auxiliary Telescope The VLT is composed of four 8.2-m Unit Telescope (Antu, Kueyen, Melipal and Yepun). They have been progressively put into service together with a vast suite of the most advanced astronomical instruments and are operated every night in the year. Contrary to other large astronomical telescopes, the VLT was designed from the beginning with the use of interferometry as a major goal. The VLT Interferometer (VLTI) combines starlight captured by two or three 8.2- VLT Unit Telescopes, dramatically increasing the spatial resolution and showing fine details of a large variety of celestial objects. ESO PR Photo 51b/06 ESO PR Photo 51b/06 One AT Under the Sky However, most of the time the large telescopes are used for other research purposes. They are therefore only available for interferometric observations during a limited number of nights every year. Thus, in order to exploit the VLTI each night and to achieve the full potential of this unique setup, some other (smaller), dedicated telescopes were included into the overall VLT concept. These telescopes, known as the VLTI Auxiliary Telescopes (ATs), are mounted on tracks and can be placed at precisely defined "parking" observing positions on the observatory platform. From these positions, their light beams are fed into the same common focal point via a complex system of reflecting mirrors mounted in an underground system of tunnels. The Auxiliary Telescopes are real technological jewels. They are placed in ultra-compact enclosures, complete with all necessary electronics, an air conditioning system and cooling liquid for

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

    NASA Astrophysics Data System (ADS)

    Bauer, C.-O.

    1980-06-01

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

  16. Joining of SiC parts by polishing and hipping

    DOEpatents

    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.

  17. 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.

  18. 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.

  19. JOINING DISSIMILAR MATERIALS USING FRICTION STIR SCRIBE TECHNIQUE

    SciTech Connect

    Upadhyay, Piyush; Hovanski, Yuri; Jana, Saumyadeep; Fifield, Leonard S.

    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 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 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.

  20. Joining Dissimilar Materials Using Friction Stir Scribe Technique

    SciTech Connect

    Upadhyay, Piyush; Hovanski, Yuri; Jana, Saumyadeep; Fifield, Leonard S.

    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 cost 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.

  1. On the unconventional amide I band in acetanilide

    NASA Astrophysics Data System (ADS)

    Tenenbaum, Alexander; Campa, Alessandro; Giansanti, Andrea

    1987-04-01

    We developed a new model to study the molecular dynamics of the acetanilide (ACN) crystal by computer simulation. Low-frequency oscillations of the molecules as a whole were considered with high-frequency vibrations of the amidic degrees of freedom involved in hydrogen bonding. The low-temperature power spectrum has two peaks, shifted by 15 cm -1, in the region of the amide I band: one of them corresponds to the so-called anomalous amide I band in the IR and Raman spectra of ACN. We found that this peak is due to the coupling of the low-frequency motion in the chain of molecules with the motion of the hydrogen-bonded protons, at variance with current suggestions.

  2. Immobilized coupling reagents: synthesis of amides/peptides.

    PubMed

    Cherkupally, Prabhakar; Ramesh, Suhas; de la Torre, Beatriz G; Govender, Thavendran; Kruger, Hendrik G; Albericio, Fernando

    2014-11-10

    The primary idea of using immobilized reagents in organic synthetic chemistry is to simplify the downstream process, product workup and isolation, and therefore avoiding time-consuming and expensive chromatographic separations, which are intrinsic to every synthetic process. Numerous polymer-bounded reagents are commercially available and applicable to almost all kinds of synthetic chemistry conversions. Herein, we have covered all known supported-coupling reagents and bases which have had a great impact in amide/peptide bond formation. These coupling reagents have been used for the activation of a carboxyl moiety; thus generating an active acylating species that is ready to couple with an amine nucleophile liberating the amide/peptide and polymeric support which can be regenerated for reuse. This also addresses a large variety of anchored coupling reagents, additives, and bases that have only been employed in amide/peptide syntheses during the last six decades.

  3. Intramolecular amide bonds stabilize pili on the surface of bacilli

    SciTech Connect

    Budzik, Jonathan M.; Poor, Catherine B.; Faull, Kym F.; Whitelegge, Julian P.; He, Chuan; Schneewind, Olaf

    2010-01-12

    Gram-positive bacteria elaborate pili and do so without the participation of folding chaperones or disulfide bond catalysts. Sortases, enzymes that cut pilin precursors, form covalent bonds that link pilin subunits and assemble pili on the bacterial surface. We determined the x-ray structure of BcpA, the major pilin subunit of Bacillus cereus. The BcpA precursor encompasses 2 Ig folds (CNA{sub 2} and CNA{sub 3}) and one jelly-roll domain (XNA) each of which synthesizes a single intramolecular amide bond. A fourth amide bond, derived from the Ig fold of CNA{sub 1}, is formed only after pilin subunits have been incorporated into pili. We report that the domains of pilin precursors have evolved to synthesize a discrete sequence of intramolecular amide bonds, thereby conferring structural stability and protease resistance to pili.

  4. Nickel-catalysed Suzuki-Miyaura coupling of amides

    NASA Astrophysics Data System (ADS)

    Weires, Nicholas A.; Baker, Emma L.; Garg, Neil K.

    2016-01-01

    The Suzuki-Miyaura coupling has become one of the most important and prevalent methods for the construction of C-C bonds. Although palladium catalysis has historically dominated the field, the use of nickel catalysis has become increasingly widespread because of its unique ability to cleave carbon-heteroatom bonds that are unreactive towards other transition metals. We report the first nickel-catalysed Suzuki-Miyaura coupling of amides, which proceeds by an uncommon cleavage of the amide C-N bond after N-tert-butoxycarbonyl activation. The methodology is mild, functional-group tolerant and can be strategically employed in sequential transition-metal-catalysed cross-coupling sequences to unite heterocyclic fragments. These studies demonstrate that amides, despite classically considered inert substrates, can be harnessed as synthons for use in reactions that form C-C bonds through cleavage of the C-N bond using non-precious metal catalysis.

  5. One-Pot Reductive 1,3-Dipolar Cycloaddition of Secondary Amides: A Two-Step Transformation of Primary Amides.

    PubMed

    Huang, Pei-Qiang; Lang, Qi-Wei; Hu, Xiu-Ning

    2016-11-04

    The one-pot reductive 1,3-dipolar cycloaddition of secondary aromatic N-(trimethylsilylmethyl)amides with reactive dipolarophiles is reported. The method relies on the in situ generation of nonstabilized NH azomethine ylide dipoles via amide activation with triflic anhydride, partial reduction with 1,1,3,3-tetramethyldisiloxane (TMDS), and desilylation with cesium fluoride (CsF). Running under mild conditions, the reaction tolerated several sensitive functional groups and provided cycloadducts in 71-93% yields. The use of less reactive dipolarophile methyl acrylate led to the cycloadduct in only 40% yield. A (Z) geometric intermediate of NH-azomethine 1,3-dipole was postulated to account for the observed higher yields and higher cis diastereoselectivity for the substrates bearing an electron-withdrawing group. This model features an unconventional cyclic transition state via carbanion-aryl ring interaction. Because the starting secondary amides can be prepared from common primary amides, the current method also constitutes a two-step transformation of primary amides.

  6. VCD Robustness of the Amide-I and Amide-II Vibrational Modes of Small Peptide Models.

    PubMed

    Góbi, Sándor; Magyarfalvi, Gábor; Tarczay, György

    2015-09-01

    The rotational strengths and the robustness values of amide-I and amide-II vibrational modes of For(AA)n NHMe (where AA is Val, Asn, Asp, or Cys, n = 1-5 for Val and Asn; n = 1 for Asp and Cys) model peptides with α-helix and β-sheet backbone conformations were computed by density functional methods. The robustness results verify empirical rules drawn from experiments and from computed rotational strengths linking amide-I and amide-II patterns in the vibrational circular dichroism (VCD) spectra of peptides with their backbone structures. For peptides with at least three residues (n ≥ 3) these characteristic patterns from coupled amide vibrational modes have robust signatures. For shorter peptide models many vibrational modes are nonrobust, and the robust modes can be dependent on the residues or on their side chain conformations in addition to backbone conformations. These robust VCD bands, however, provide information for the detailed structural analysis of these smaller systems.

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

    NASA Astrophysics Data System (ADS)

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

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

  8. The temperature dependent amide I band of crystalline acetanilide

    NASA Astrophysics Data System (ADS)

    Cruzeiro, Leonor; Freedman, Holly

    2013-10-01

    The temperature dependent anomalous peak in the amide I band of crystalline acetanilide is thought to be due to self-trapped states. On the contrary, according to the present model, the anomalous peak comes from the fraction of ACN molecules strongly hydrogen-bonded to a neighboring ACN molecule, and its intensity decreases because, on average, this fraction decreases as temperature increases. This model provides, for the first time, an integrated and theoretically consistent view of the temperature dependence of the full amide I band and a qualitative explanation of some of the features of nonlinear pump-probe experiments.

  9. Amides Do Not Always Work: Observation of Guest Binding in an Amide-Functionalized Porous Metal–Organic Framework

    PubMed Central

    2016-01-01

    An amide-functionalized metal organic framework (MOF) material, MFM-136, shows a high CO2 uptake of 12.6 mmol g–1 at 20 bar and 298 K. MFM-136 is the first example of an acylamide pyrimidyl isophthalate MOF without open metal sites and, thus, provides a unique platform to study guest binding, particularly the role of free amides. Neutron diffraction reveals that, surprisingly, there is no direct binding between the adsorbed CO2/CH4 molecules and the pendant amide group in the pore. This observation has been confirmed unambiguously by inelastic neutron spectroscopy. This suggests that introduction of functional groups solely may not necessarily induce specific guest–host binding in porous materials, but it is a combination of pore size, geometry, and functional group that leads to enhanced gas adsorption properties. PMID:27665845

  10. Amides Do Not Always Work: Observation of Guest Binding in an Amide-Functionalized Porous Metal-Organic Framework.

    PubMed

    Benson, Oguarabau; da Silva, Ivan; Argent, Stephen P; Cabot, Rafel; Savage, Mathew; Godfrey, Harry G W; Yan, Yong; Parker, Stewart F; Manuel, Pascal; Lennox, Matthew J; Mitra, Tamoghna; Easun, Timothy L; Lewis, William; Blake, Alexander J; Besley, Elena; Yang, Sihai; Schröder, Martin

    2016-11-16

    An amide-functionalized metal organic framework (MOF) material, MFM-136, shows a high CO2 uptake of 12.6 mmol g(-1) at 20 bar and 298 K. MFM-136 is the first example of an acylamide pyrimidyl isophthalate MOF without open metal sites and, thus, provides a unique platform to study guest binding, particularly the role of free amides. Neutron diffraction reveals that, surprisingly, there is no direct binding between the adsorbed CO2/CH4 molecules and the pendant amide group in the pore. This observation has been confirmed unambiguously by inelastic neutron spectroscopy. This suggests that introduction of functional groups solely may not necessarily induce specific guest-host binding in porous materials, but it is a combination of pore size, geometry, and functional group that leads to enhanced gas adsorption properties.

  11. Ultrasound-assisted direct oxidative amidation of benzyl alcohols catalyzed by graphite oxide.

    PubMed

    Mirza-Aghayan, Maryam; Ganjbakhsh, Nahid; Molaee Tavana, Mahdieh; Boukherroub, Rabah

    2016-09-01

    Ultrasound irradiation was successfully applied for the direct oxidative amidation of benzyl alcohols with amines into the corresponding amides using graphite oxide (GO) as an oxidative and reusable solid acid catalyst in acetonitrile as solvent at 50°C under air atmosphere. The direct oxidative amidation of benzyl alcohols takes place under mild conditions yielding the corresponding amides in good to high yields (69-95%) and short reaction times under metal-free conditions.

  12. Novel apparatus for joining of carbon-carbon composites

    NASA Astrophysics Data System (ADS)

    White, Jeremiah D. E.; Mukasyan, Alexander S.; La Forest, Mark L.; Simpson, Allen H.

    2007-01-01

    A novel apparatus for joining carbon-carbon (C-C) composites is presented. This device was designed and built based on the concept of self-sustained oxygen-free high-temperature reactions. A layer of reactive mixture is contained between two disks of C-C composite that are to be joined. The stack is held in place between two electrodes, which are connected to a dc power supply. dc current is used to uniformly initiate the reaction in the reactive layer. The electrodes are also part of the pneumatic system, which applies a load to the stack. The designed hydraulic system is effective, lending to low cost and simplified, rapid, accurate operation. It provides a very short response time (˜10ms), which is important for the considered applications. All operational parameters such as initial and final loads, applied current, delay time between ignition and final load application, duration of Joule heating, and safety interlocks are controlled by a programable logic controller system. These features make it an efficient, user-friendly and safe machine to join refractory materials. The entire joining process takes place on the order of seconds, rather than hours as required for solid-state joining methods. The mechanical properties of the obtained joints are higher than those for the C-C composites.

  13. Research on microwave joining of SiC

    SciTech Connect

    Silberglitt, R.

    1995-07-31

    Results: identification of optimum joining temperature range for reaction bonded Si carbide at 1420-1500 C; demonstration that specimens joined within this range have fracture roughness greater than as-received material; and demonstration of ability to use SiC formed in situ from the decomposition of polycarbosilane as a joining aid for sintered Si carbide. In the latter case, the interlayer material was also shown to fill any pores in the joining specimens near the interlayer. Together with the demonstration of leaktight joints between tube sections of reaction bonded and sintered SiC under the previous contract, these results provide the foundation for scaleup to joining of the larger and longer tubes needed for radiant burner and heat exchanger tube assemblies. The formation of SiC in situ is important because maintaining roundness of these large tubes is a technical challenge for the tube manufacturer, so that formation of a leaktight joint may require some degree of gap filling.

  14. 40 CFR 721.10589 - Unsaturated fatty acids, amides with polyethylenepolyamine (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Unsaturated fatty acids, amides with... Specific Chemical Substances § 721.10589 Unsaturated fatty acids, amides with polyethylenepolyamine... identified generically as unsaturated fatty acids, amides with polyethylenepolyamine (PMN P-11-106)...

  15. 40 CFR 721.10590 - Fatty acids, amides with triethylentetramine (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Fatty acids, amides with... Specific Chemical Substances § 721.10590 Fatty acids, amides with triethylentetramine (generic). (a... generically as fatty acids, amides with triethylentetramine (PMN P-11-107) is subject to reporting under...

  16. 40 CFR 721.10589 - Unsaturated fatty acids, amides with polyethylenepolyamine (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Unsaturated fatty acids, amides with... Specific Chemical Substances § 721.10589 Unsaturated fatty acids, amides with polyethylenepolyamine... identified generically as unsaturated fatty acids, amides with polyethylenepolyamine (PMN P-11-106)...

  17. 40 CFR 721.10590 - Fatty acids, amides with triethylentetramine (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Fatty acids, amides with... Specific Chemical Substances § 721.10590 Fatty acids, amides with triethylentetramine (generic). (a... generically as fatty acids, amides with triethylentetramine (PMN P-11-107) is subject to reporting under...

  18. 40 CFR 721.10176 - Amides, peanut-oil, N-[3-(dimethylamino)propyl].

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Amides, peanut-oil, N- . 721.10176... Substances § 721.10176 Amides, peanut-oil, N- . (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amides, peanut-oil, N- (PMN P-04-144; CAS No....

  19. 40 CFR 721.10176 - Amides, peanut-oil, N-[3-(dimethylamino)propyl].

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Amides, peanut-oil, N- . 721.10176... Substances § 721.10176 Amides, peanut-oil, N- . (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amides, peanut-oil, N- (PMN P-04-144; CAS No....

  20. 40 CFR 721.10176 - Amides, peanut-oil, N-[3-(dimethylamino)propyl].

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Amides, peanut-oil, N- . 721.10176... Substances § 721.10176 Amides, peanut-oil, N- . (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amides, peanut-oil, N- (PMN P-04-144; CAS No....

  1. 40 CFR 721.10176 - Amides, peanut-oil, N-[3-(dimethylamino)propyl].

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Amides, peanut-oil, N- . 721.10176... Substances § 721.10176 Amides, peanut-oil, N- . (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amides, peanut-oil, N- (PMN P-04-144; CAS No....

  2. 40 CFR 721.10176 - Amides, peanut-oil, N-[3-(dimethylamino)propyl].

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Amides, peanut-oil, N- . 721.10176... Substances § 721.10176 Amides, peanut-oil, N- . (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amides, peanut-oil, N- (PMN P-04-144; CAS No....

  3. 40 CFR 721.10192 - Amides, coco, N-[3-(dibutylamino)propyl], acrylates.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Amides, coco, N- , acrylates. 721... Substances § 721.10192 Amides, coco, N- , acrylates. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amides, coco, N- , acrylates (PMN...

  4. 40 CFR 721.10192 - Amides, coco, N-[3-(dibutylamino)propyl], acrylates.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Amides, coco, N- , acrylates. 721... Substances § 721.10192 Amides, coco, N- , acrylates. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amides, coco, N- , acrylates (PMN...

  5. 40 CFR 721.10191 - Amides, coco, N-[3-(dibutylamino)propyl].

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Amides, coco, N- . 721.10191 Section... Substances § 721.10191 Amides, coco, N- . (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amides, coco, N- (PMN P-06-262; CAS No. 851544-20-2)...

  6. 40 CFR 721.10192 - Amides, coco, N-[3-(dibutylamino)propyl], acrylates.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Amides, coco, N- , acrylates. 721... Substances § 721.10192 Amides, coco, N- , acrylates. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amides, coco, N- , acrylates (PMN...

  7. 40 CFR 721.10192 - Amides, coco, N-[3-(dibutylamino)propyl], acrylates.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Amides, coco, N- , acrylates. 721... Substances § 721.10192 Amides, coco, N- , acrylates. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amides, coco, N- , acrylates (PMN...

  8. 40 CFR 721.10191 - Amides, coco, N-[3-(dibutylamino)propyl].

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Amides, coco, N- . 721.10191 Section... Substances § 721.10191 Amides, coco, N- . (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amides, coco, N- (PMN P-06-262; CAS No. 851544-20-2)...

  9. 40 CFR 721.10191 - Amides, coco, N-[3-(dibutylamino)propyl].

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Amides, coco, N- . 721.10191 Section... Substances § 721.10191 Amides, coco, N- . (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amides, coco, N- (PMN P-06-262; CAS No. 851544-20-2)...

  10. 40 CFR 721.10191 - Amides, coco, N-[3-(dibutylamino)propyl].

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Amides, coco, N- . 721.10191 Section... Substances § 721.10191 Amides, coco, N- . (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as amides, coco, N- (PMN P-06-262; CAS No. 851544-20-2)...

  11. Use of triphenyl phosphate as risk mitigant for metal amide hydrogen storage materials

    DOEpatents

    Cortes-Concepcion, Jose A.; Anton, Donald L.

    2016-04-26

    A process in a resulting product of the process in which a hydrogen storage metal amide is modified by a ball milling process using an additive of TPP. The resulting product provides for a hydrogen storage metal amide having a coating that renders the hydrogen storage metal amide resistant to air, ambient moisture, and liquid water while improving useful hydrogen storage and release kinetics.

  12. 40 CFR 721.10512 - Fatty acid maleic acid amides (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Fatty acid maleic acid amides (generic... Specific Chemical Substances § 721.10512 Fatty acid maleic acid amides (generic). (a) Chemical substance... fatty acid maleic acid amides (PMNs P-07-563 and P-07-564) are subject to reporting under this...

  13. 40 CFR 721.10512 - Fatty acid maleic acid amides (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Fatty acid maleic acid amides (generic... Specific Chemical Substances § 721.10512 Fatty acid maleic acid amides (generic). (a) Chemical substance... fatty acid maleic acid amides (PMNs P-07-563 and P-07-564) are subject to reporting under this...

  14. KNH2-KH: a metal amide-hydride solid solution.

    PubMed

    Santoru, Antonio; Pistidda, Claudio; Sørby, Magnus H; Chierotti, Michele R; Garroni, Sebastiano; Pinatel, Eugenio; Karimi, Fahim; Cao, Hujun; Bergemann, Nils; Le, Thi T; Puszkiel, Julián; Gobetto, Roberto; Baricco, Marcello; Hauback, Bjørn C; Klassen, Thomas; Dornheim, Martin

    2016-09-27

    We report for the first time the formation of a metal amide-hydride solid solution. The dissolution of KH into KNH2 leads to an anionic substitution, which decreases the interaction among NH2(-) ions. The rotational properties of the high temperature polymorphs of KNH2 are thereby retained down to room temperature.

  15. Universal mechanism for breaking amide bonds by ionizing radiation.

    PubMed

    Johnson, Phillip S; Cook, Peter L; Liu, Xiaosong; Yang, Wanli; Bai, Yiqun; Abbott, Nicholas L; Himpsel, F J

    2011-07-28

    The photodissociation of the amide bond by UV light and soft x-rays is investigated by x-ray absorption spectroscopy at the C, N, and O 1s edges. Irradiation leaves a clear and universal signature for a wide variety of amides, ranging from oligopeptides to large proteins and synthetic polyamides, such as nylon. As the π∗ peak of the amide bond shrinks, two new π∗ peaks appear at the N 1s edge with a characteristic splitting of 1.1 eV. An additional characteristic is the overall intensity reduction of both the π∗ and σ∗ features at the O 1s edge, which indicates loss of oxygen. The spectroscopic results are consistent with the release of the O atom from the amide bond, followed by the migration of the H atom from the N to one of its two C neighbors. Migration to the carbonyl C leads to an imine, and migration to the C(α) of the amino acid residue leads to a nitrile. Imine and nitrile produce the two characteristic π∗ transitions at the N 1s edge. A variety of other models is considered and tested against the N 1s spectra of reference compounds.

  16. Differential induction of redox sensitive extracellular phenolic amides in potato

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study focuses on the differential induction of extracellular phenolic amides that accumulate in potato cell suspensions during the first few hours of the interaction between these plant cells and bacterial pathogens or pathogen-related elicitors. Using suspension cells of Solanum tuberosum we ...

  17. Stereoselective Synthesis of Spirooxindole Amides through Nitrile Hydrozirconation

    PubMed Central

    Lu, Chunliang; Xiao, Qing; Floreancig, Paul E.

    2010-01-01

    Spirooxindole amides can be prepared by the intramolecular addition of functionalized indoles into acyliminium ions that are accessed from nitriles by hydrozirconation and acylation. The stereochemical outcome at the quaternary center was controlled by the steric bulk of the substituent at the 2-position of the indole unit. The products are well-suited for diversification to prepare libraries. PMID:20961073

  18. Amides and Hydrazides from Amine and Hydrazine Hydrochlorides.

    ERIC Educational Resources Information Center

    Shama, Sami A.; Tran, Thuan L.

    1978-01-01

    This safe and efficient procedure for the synthesis of N-substituted amides and hydrazides is a modification of the Schotten-Bausmann procedure in which the amine or hydrazide is replaced by the corresponding hydrochloride salt, and the use of alkali is eliminated. (Author/BB)

  19. Method for enhancing amidohydrolase activity of fatty acid amide hydrolase

    SciTech Connect

    John, George; Nagarajan, Subbiah; Chapman, Kent; Faure, Lionel; Koulen, Peter

    2016-10-25

    A method for enhancing amidohydrolase activity of Fatty Acid Amide Hydrolase (FAAH) is disclosed. The method comprising administering a phenoxyacylethanolamide that causes the enhanced activity. The enhanced activity can have numerous effects on biological organisms including, for example, enhancing the growth of certain seedlings. The subject matter disclosed herein relates to enhancers of amidohydrolase activity.

  20. 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.

  1. 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.

  2. Physical attributes of some clouds amid a forest ecosystem's trees

    NASA Astrophysics Data System (ADS)

    DeFelice, T. P.

    Cloud or fog water collected by forest canopies of any elevation could represent significant sources of required moisture and nutrients for forest ecosystems, human consumption, and as an alternative source of water for agriculture and domestic use. The physical characteristics of fogs and other clouds have been well studied, and this information can be useful to water balance or canopy-cloud interaction model verification and to calibration or training of satellite-borne sensors to recognize atmospheric attributes, such as optical thickness, albedo, and cloud properties. These studies have taken place above-canopy or within canopy clearings and rarely amid the canopy. Simultaneous physical and chemical characteristics of clouds amid and above the trees of a mountain forest, located about 3.3 km southwest of Mt. Mitchell, NC, were collected between 13 and 22 June 1993. This paper summarizes the physical characteristics of the cloud portions amid the trees. The characteristic cloud amid the trees (including cloud and precipitation periods) contained 250 droplet/cm 3 with a mean diameter of 9.5 μm and liquid water content (LWC) of 0.11 g m -3. The cloud droplets exhibited a bimodal distribution with modes at about 2 and 8 μm and a mean diameter near 5 μm during precipitation-free periods, whereas the concurrent above-canopy cloud droplets had a unimodal distribution with a mode near 6 μm and a mean diameter of 6 μm. The horizontal cloud water flux is nonlinearly related to the rate of collection onto that surface amid the trees, especially for the Atmospheric Sciences Research Center (ASRC) sampling device, whereas it is linear when the forward scattering spectrometer probe (FSSP) are is used. These findings suggest that statements about the effects clouds have on surfaces they encounter, which are based on above-canopy or canopy-clearing data, can be misleading, if not erroneous.

  3. 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.

  4. Superplasticity and joining of zirconia-based ceramics

    SciTech Connect

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

    2000-07-01

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

  5. Liquid-solid joining of bulk metallic glasses

    PubMed Central

    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

  6. 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.

  7. Liquid-solid joining of bulk metallic glasses.

    PubMed

    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.

  8. Joining three car body steel sheets by clinching method

    NASA Astrophysics Data System (ADS)

    Kaščák, Ľuboš; Spišák, Emil; Majerníková, Jana

    2016-12-01

    The optimization of a car body in terms of cost can be achieved by using different materials in various positions of the car in order to utilize specific properties of each different material. Resistance spot welding is the most used method of joining in car body production, but it is not always easy or even possible to join some combination of materials by this method. Clinching is an alternative method to spot welding, as a combination of drawing and forming. The research is focused on the evaluation of clinched joints' properties using shearing test and metallographic observation of material structure.

  9. Investigating Thermal Interactions in the Case of Laser Assisted Joining of PMMA Plastic and Steel

    NASA Astrophysics Data System (ADS)

    Bauernhuber, Andor; Markovits, Tamás

    Laser transmission joining of dissimilar materials is a novel and promising area of researches on joining technology. However, processes during laser assisted metal plastic (LAMP) joining are not completely explained yet. In the course of this study, the authors investigated the joining process of PMMA plastic and steel by means of laser, as a part of their research on dissimilar material joining. The characteristic process temperature was measured during the joining by different heating conditions, to describe thermal interactions between the polymer and the metal part, and to better understand the mechanism of joining.

  10. Torsional Shear Strength Tests for Glass-Ceramic Joined Silicon Carbide

    DOE PAGES

    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

  11. Torsional Shear Strength Tests for Glass-Ceramic Joined Silicon Carbide

    SciTech Connect

    Ferraris, Monica; Ventrella, Andrea; Salvo, Milena; Katoh, Yutai; Gross, Dietmar

    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 their joined area.

  12. Semi-catalytic reduction of secondary amides to imines and aldehydes.

    PubMed

    Lee, Sun-Hwa; Nikonov, Georgii I

    2014-06-21

    Secondary amides can be reduced by silane HSiMe2Ph into imines and aldehydes by a two-stage process involving prior conversion of amides into iminoyl chlorides followed by catalytic reduction mediated by the ruthenium complex [Cp(i-Pr3P)Ru(NCCH3)2]PF6 (1). Alkyl and aryl amides bearing halogen, ketone, and ester groups were converted with moderate to good yields under mild reaction conditions to the corresponding imines and aldehydes. This procedure does not work for substrates bearing the nitro-group and fails for heteroaromatic amides. In the case of cyano substituted amides, the cyano group is reduced to imine.

  13. Amide I'-II' 2D IR spectroscopy provides enhanced protein secondary structural sensitivity.

    PubMed

    Deflores, Lauren P; Ganim, Ziad; Nicodemus, Rebecca A; Tokmakoff, Andrei

    2009-03-11

    We demonstrate how multimode 2D IR spectroscopy of the protein amide I' and II' vibrations can be used to distinguish protein secondary structure. Polarization-dependent amide I'-II' 2D IR experiments on poly-l-lysine in the beta-sheet, alpha-helix, and random coil conformations show that a combination of amide I' and II' diagonal and cross peaks can effectively distinguish between secondary structural content, where amide I' infrared spectroscopy alone cannot. The enhanced sensitivity arises from frequency and amplitude correlations between amide II' and amide I' spectra that reflect the symmetry of secondary structures. 2D IR surfaces are used to parametrize an excitonic model for the amide I'-II' manifold suitable to predict protein amide I'-II' spectra. This model reveals that the dominant vibrational interaction contributing to this sensitivity is a combination of negative amide II'-II' through-bond coupling and amide I'-II' coupling within the peptide unit. The empirically determined amide II'-II' couplings do not significantly vary with secondary structure: -8.5 cm(-1) for the beta sheet, -8.7 cm(-1) for the alpha helix, and -5 cm(-1) for the coil.

  14. Women's Heart Disease: Join the Heart Truth Community

    MedlinePlus

    ... 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 ...

  15. 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…

  16. Efficient and scalable graph similarity joins in MapReduce.

    PubMed

    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.

  17. Novel Metal-Ceramic Joining for Planar SOFCs

    SciTech Connect

    Kim, Jin Yong Y.; Hardy, John S.; Weil, K. Scott

    2005-05-01

    We are investigating a new method of ceramic-to-metal joining, referred to as reactive air brazing (RAB), as a potential method of sealing planar solid oxide fuel cells (SOFCs). In the present study, yttria stabilized zirconia (YSZ) and FeCrAlY were selected as subject materials in order to simulate the cell-to-frame seal in planar SOFC. YSZ plates were joined with FeCrAlY foils, using various CuO-Ag and CuO-Ag-TiO2 braze compositions. Metallographic analysis revealed that a majority of the CuO in the braze preferentially migrates to the braze/FeCrAlY interface, indicating a stronger affinity and interaction between the CuO and the alumina scale that had formed on the FeCrAlY than with the YSZ substrate. The addition of TiO2 to the braze appeared to have no significant effect on the microstructure or mechanical properties of the YSZ/FeCrAlY joints, unlike what had been observed previously in YSZ/YSZ joining. Four-point bend tests indicated that joint strength improves with increasing CuO content up to 8 mol% CuO, the maximum concentration of copper oxide tetsed, likely due to the concomitant improvement in braze wettability. A maximum bend strength of 101 MPa was achieved using the 8 mol% CuO braze composition, demonstrating the feasibility of this joining technique for sealing planar SOFCs.

  18. Join-A-School Survey: District Summary Report.

    ERIC Educational Resources Information Center

    Albuquerque Public Schools, NM.

    This report summarizes responses to a questionnaire sent to both school and business participants in the Join-A-School Program in Albuquerque, New Mexico. The program, which pairs schools and businesses within a community, was originated in 1985; this survey is the first evaluation of the program. Responses were received from 47% of the business…

  19. 5 CFR 1201.36 - Consolidating and joining appeals.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    .... For example, individual appeals rising from a single reduction in force might be consolidated. (2... 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....

  20. 5 CFR 1201.36 - Consolidating and joining appeals.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    .... For example, individual appeals rising from a single reduction in force might be consolidated. (2... 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....

  1. 5 CFR 1201.36 - Consolidating and joining appeals.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    .... For example, individual appeals rising from a single reduction in force might be consolidated. (2... 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....

  2. 91. VIEW OF THE SOUTHWEST CORNER WHERE THE TOWER JOINS ...

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

    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

  3. Incoming Students' Alcohol Use and Intent to Join Greek Organizations

    ERIC Educational Resources Information Center

    Oswalt, Sara B.; Shutt, Michael D.; Cooper, Diane L.

    2006-01-01

    Incoming first-time, first-year students attending summer orientation (N = 1,710) at a large public university in the Southeast completed an instrument that assessed their use of alcohol and other drugs during the previous year, their perceptions of use by current students on campus, their intended alcohol use, and their intent to join a Greek…

  4. 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.

  5. Joining and fabrication of metal-matrix composite materials

    NASA Technical Reports Server (NTRS)

    Royster, D. M.; Wiant, H. R.; Bales, T. T.

    1975-01-01

    Manufacturing technology associated with developing fabrication processes to incorporate metal-matrix composites into flight hardware is studied. The joining of composite to itself and to titanium by innovative brazing, diffusion bonding, and adhesive bonding is examined. The effects of the fabrication processes on the material properties and their influence on the design of YF-12 wing panels are discussed.

  6. On the optimality of the neighbor-joining algorithm

    PubMed Central

    Eickmeyer, Kord; Huggins, Peter; Pachter, Lior; Yoshida, Ruriko

    2008-01-01

    The popular neighbor-joining (NJ) algorithm used in phylogenetics is a greedy algorithm for finding the balanced minimum evolution (BME) tree associated to a dissimilarity map. From this point of view, NJ is "optimal" when the algorithm outputs the tree which minimizes the balanced minimum evolution criterion. We use the fact that the NJ tree topology and the BME tree topology are determined by polyhedral subdivisions of the spaces of dissimilarity maps R+(n2) to study the optimality of the neighbor-joining algorithm. In particular, we investigate and compare the polyhedral subdivisions for n ≤ 8. This requires the measurement of volumes of spherical polytopes in high dimension, which we obtain using a combination of Monte Carlo methods and polyhedral algorithms. Our results include a demonstration that highly unrelated trees can be co-optimal in BME reconstruction, and that NJ regions are not convex. We obtain the l2 radius for neighbor-joining for n = 5 and we conjecture that the ability of the neighbor-joining algorithm to recover the BME tree depends on the diameter of the BME tree. PMID:18447942

  7. Price Chopper Joins EPAs Food Recovery Challenge Program

    EPA Pesticide Factsheets

    (New York, NY - January 14, 2016) Today, U.S. Environmental Protection Agency Regional Administrator Judith A. Enck was joined by Mona Golub, Vice President of Public Relations and Consumer Services for Price Chopper and Market 32; Joseph Berman, Manager o

  8. 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

  9. Amino alcohol-based degradable poly(ester amide) elastomers

    PubMed Central

    Bettinger, Christopher J.; Bruggeman, Joost P.; Borenstein, Jeffrey T.; Langer, Robert S.

    2009-01-01

    Currently available synthetic biodegradable elastomers are primarily composed of crosslinked aliphatic polyesters, which suffer from deficiencies including (1) high crosslink densities, which results in exceedingly high stiffness, (2) rapid degradation upon implantation, or (3) limited chemical moieties for chemical modification. Herein, we have developed poly(1,3-diamino-2-hydroxypropane-co-polyol sebacate)s, a new class of synthetic, biodegradable elastomeric poly(ester amide)s composed of crosslinked networks based on an amino alcohol. These crosslinked networks feature tensile Young’s modulus on the order of 1 MPa and reversable elongations up to 92%. These polymers exhibit in vitro and in vivo biocompatibility. These polymers have projected degradation half-lives up to 20 months in vivo. PMID:18295329

  10. New substituted amides and hydrazides of pectic acid

    SciTech Connect

    Lapenko, V.L.; Potapova, L.B.; Slivkin, A.I.; Razumnaya, Z.A.

    1988-05-10

    Structural variants of pectin amides and hydrazides are of practical value as flocculants in water treatment. The purpose of this work was to further investigate the synthesis of substituted amides and hydrazides of pectic acid and to study their activity as flocculants. They used pectin, methylation products of pectin, pectic acid, and methyl pectates. The synthesized analogs of pectinic materials containing nitrogen are essentially copolymers of hydrazido (amido) and carboxyl (methoxyl) derivatives of D-galacturonic acid. The flocculant activity of the new polymers was monitored with simulated drainage water containing kaolin or abrasive powder (for glass manufacture) in the presence of polyvalent metal ions. The use of the new ampholytic flocculants in the purification of water from suspended impurities permits a high degree of clarification with a sharp decrease in reagent consumption.

  11. Simple Amides of Oleanolic Acid as Effective Penetration Enhancers

    PubMed Central

    Bednarczyk-Cwynar, Barbara; Partyka, Danuta; Zaprutko, Lucjusz

    2015-01-01

    Transdermal transport is now becoming one of the most convenient and safe pathways for drug delivery. In some cases it is necessary to use skin penetration enhancers in order to allow for the transdermal transport of drugs that are otherwise insufficiently skin-permeable. A series of oleanolic acid amides as potential transdermal penetration enhancers was formed by multistep synthesis and the synthesis of all newly prepared compounds is presented. The synthetized amides of oleanolic acid were tested for their in vitro penetration promoter activity. The above activity was evaluated by means of using the Fürst method. The relationships between the chemical structure of the studied compounds and penetration activity are presented. PMID:26010090

  12. Fine structure of the amide i band in acetanilide

    NASA Astrophysics Data System (ADS)

    Careri, G.; Gratton, E.; Shyamsunder, E.

    1988-05-01

    Their absorption spectrum of both single crystals and powdered samples of acetanilide (a model system for proteins) has been studied in the amide i region, where a narrow band has been identified as a highly trapped soliton state. The powder-sample spectra have been decomposed using four Lorentzian bands. A strong temperature dependence has been found for the intensity of two of the subbands, which also show a complementary behavior. Polarization studies performed on thin crystals have shown that the subbands have the same polarization. Low-temperature spectra of partially deuterated samples show the presence of the subbands at the same absorption frequencies found using the fitting procedure in the spectra of nondeuterated samples. The soliton model currently proposed to explain the origin of the anomalous amide i component at 1650 cm-1 still holds, but some modification of the model is required to account for the new features revealed by this study.

  13. Enzymatic synthesis of fatty amides from palm olein.

    PubMed

    Al-Mulla, Emad A Jaffar; Yunus, Wan Md Zin Wan; Ibrahim, Nor Azowa Bt; Rahman, Mohd Zaki A

    2010-01-01

    Fatty amides have been successfully synthesized from palm olein and urea by a one-step lipase catalyzed reaction. The use of immobilized lipase as the catalyst for the preparation reaction provides an easy isolation of the enzyme from the products and other components in the reaction mixture. The fatty amides were characterized using Fourier transform infrared (FTIR) spectroscopy, proton nuclear magnetic resonance ((1)H NMR) technique and elemental analysis. The highest conversion percentage (96%) was obtained when the process was carried out for 36 hours using urea to palm oil ratio of 5.2: 1.0 at 40 degrees C. The method employed offers several advantages such as renewable and abundant of the raw material, simple reaction procedure, environmentally friendly process and high yield of the product.

  14. Potent and orally efficacious benzothiazole amides as TRPV1 antagonists.

    PubMed

    Besidski, Yevgeni; Brown, William; Bylund, Johan; Dabrowski, Michael; Dautrey, Sophie; Harter, Magali; Horoszok, Lucy; Hu, Yin; Johnson, Dean; Johnstone, Shawn; Jones, Paul; Leclerc, Sandrine; Kolmodin, Karin; Kers, Inger; Labarre, Maryse; Labrecque, Denis; Laird, Jennifer; Lundström, Therese; Martino, John; Maudet, Mickaël; Munro, Alexander; Nylöf, Martin; Penwell, Andrea; Rotticci, Didier; Slaitas, Andis; Sundgren-Andersson, Anna; Svensson, Mats; Terp, Gitte; Villanueva, Huascar; Walpole, Christopher; Zemribo, Ronald; Griffin, Andrew M

    2012-10-01

    Benzothiazole amides were identified as TRPV1 antagonists from high throughput screening using recombinant human TRPV1 receptor and structure-activity relationships were explored to pinpoint key pharmacophore interactions. By increasing aqueous solubility, through the attachment of polar groups to the benzothiazole core, and enhancing metabolic stability, by blocking metabolic sites, the drug-like properties and pharmokinetic profiles of benzothiazole compounds were sufficiently optimized such that their therapeutic potential could be verified in rat pharmacological models of pain.

  15. Amide and Peptide Bond Formation in Water at Room Temperature.

    PubMed

    Gabriel, Christopher M; Keener, Megan; Gallou, Fabrice; Lipshutz, Bruce H

    2015-08-21

    A general and environmentally responsible method for the formation of amide/peptide bonds in an aqueous micellar medium is described. Use of uronium salt (1-cyano-2-ethoxy-2-oxoethylidenaminooxy)dimethylaminomorpholinocarbenium hexafluorophosphate (COMU) as a coupling reagent, 2,6-lutidine, and TPGS-750-M represents mild conditions associated with these valuable types of couplings. The aqueous reaction medium is recyclable leading to low E Factors.

  16. Macrocycle Synthesis by Chloride-Templated Amide Bond Formation.

    PubMed

    Martí-Centelles, Vicente; Burguete, M Isabel; Luis, Santiago V

    2016-03-04

    A new family of pseudopeptidic macrocyclic compounds has been prepared involving an anion-templated amide bond formation reaction at the macrocyclization step. Chloride anion was found to be the most efficient template in the macrocyclization process, producing improved macrocyclization yields with regard to the nontemplated reaction. The data suggest a kinetic effect of the chloride template, providing an appropriate folded conformation of the open-chain precursor and reducing the energy barrier for the formation of the macrocyclic product.

  17. Optimization of amide-based EP3 receptor antagonists.

    PubMed

    Lee, Esther C Y; Futatsugi, Kentaro; Arcari, Joel T; Bahnck, Kevin; Coffey, Steven B; Derksen, David R; Kalgutkar, Amit S; Loria, Paula M; Sharma, Raman

    2016-06-01

    Prostaglandin E receptor subtype 3 (EP3) antagonism may treat a variety of symptoms from inflammation to cardiovascular and metabolic diseases. Previously, most EP3 antagonists were large acidic ligands that mimic the substrate, prostaglandin E2 (PGE2). This manuscript describes the optimization of a neutral small molecule amide series with improved lipophilic efficiency (LipE) also known as lipophilic ligand efficiency (LLE) ((a) Nat. Rev. Drug Disc.2007, 6, 881; (b) Annu. Rep. Med. Chem.2010, 45, 380).

  18. T. thermophila group I introns that cleave amide bonds

    NASA Technical Reports Server (NTRS)

    Joyce, Gerald F. (Inventor)

    1997-01-01

    The present invention relates to nucleic acid enzymes or enzymatic RNA molecules that are capable of cleaving a variety of bonds, including phosphodiester bonds and amide bonds, in a variety of substrates. Thus, the disclosed enzymatic RNA molecules are capable of functioning as nucleases and/or peptidases. The present invention also relates to compositions containing the disclosed enzymatic RNA molecule and to methods of making, selecting, and using such enzymes and compositions.

  19. Rapid Access to 3-Aminoindazoles from Tertiary Amides.

    PubMed

    Cyr, Patrick; Régnier, Sophie; Bechara, William S; Charette, André B

    2015-07-17

    A two-step synthesis of structurally diverse 3-aminoindazoles from readily available starting materials was developed. This sequence includes a one-pot synthesis of aminohydrazones through chemoselective Tf2O-mediated activation of tertiary amides and subsequent addition of nucleophilic hydrazides. These precursors then participate in an intramolecular ligand-free Pd-catalyzed C-H amination reaction. The azaheterocycles synthesized via this approach were further diversified through subsequent deprotection/functionalization reactions.

  20. Isotope-enriched protein standards for computational amide I spectroscopy

    SciTech Connect

    Reppert, Mike; Roy, Anish R.; Tokmakoff, Andrei

    2015-03-28

    We present a systematic isotope labeling study of the protein G mutant NuG2b as a step toward the production of reliable, structurally stable, experimental standards for amide I infrared spectroscopic simulations. By introducing isotope enriched amino acids into a minimal growth medium during bacterial expression, we induce uniform labeling of the amide bonds following specific amino acids, avoiding the need for chemical peptide synthesis. We use experimental data to test several common amide I frequency maps and explore the influence of various factors on map performance. Comparison of the predicted absorption frequencies for the four maps tested with empirical assignments to our experimental spectra yields a root-mean-square error of 6-12 cm{sup −1}, with outliers of at least 12 cm{sup −1} in all models. This means that the predictions may be useful for predicting general trends such as changes in hydrogen bonding configuration; however, for finer structural constraints or absolute frequency assignments, the models are unreliable. The results indicate the need for careful testing of existing literature maps and shed light on possible next steps for the development of quantitative spectral maps.

  1. Synthesis and comprehensive structural studies of a novel amide based carboxylic acid derivative: Non-covalent interactions

    NASA Astrophysics Data System (ADS)

    Chahkandi, Mohammad; Bhatti, Moazzam H.; Yunus, Uzma; Shaheen, Shahida; Nadeem, Muhammad; Tahir, Muhammad Nawaz

    2017-04-01

    The presented work studies the geometric and electronic structures of the crystalline network of a novel amide based carboxylic acid derivative, N-[(4-chlorophenyl)]-4-oxo-4-[oxy] butane amide, C10H10NO3Cl (1), constructed via hydrogen bonds (HBs) and stacking non-covalent interactions. Compound 1 was synthesized and characterized by FTIR, 1H, and 13C NMR, and UV-Vis spectra, X-ray structural, DTA-TG, and EI-MS, analyses. DFT calculations about molecular and related network of 1 were performed at hybrid B3LYP/6-311+G (d, p) level of theory to support the experimental data. The neutral monomeric structures join together via inter-molecular conventional O/Nsbnd H⋯O and non-conventional Csbnd H⋯O HBs and Osbnd H···π and Csbnd O···π stacking interactions to create 2-D architecture of the network. The results of dispersion corrected density functional theory (DFT-D) calculations within the binding energy of the constructive non-covalent interactions demonstrate that HBs, especially conventional Osbnd H⋯O and Nsbnd H⋯O, govern the network formation. The calculated electronic spectrum show six major bands in the range of 180-270 nm which confirm the experimental one within an intense band around 250 nm. These charge transfer bands result from shift of lone pair electron density of phenyl to chlorine or hydroxyl or phenyl functional groups that possess π → π* and π → n characters.

  2. 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.

  3. Thermal and electrical comparison of different joining techniques

    NASA Astrophysics Data System (ADS)

    Szałapak, J.; Kiełbasiński, K.; Krzemiński, J.; Pawłowski, R.; Jakubowska, M.

    2016-09-01

    After the enforcement of Restriction of Hazardous Substances Directive, one of the biggest problems in electronics is finding a substitution for led solders. Meanwhile, working conditions for the electronics are tougher and tougher - the temperatures the joints have to withstand can be much higher than working temperatures of the soft solders. In current article, the authors present the Low Temperature Joining Technique (LTJT) with the use of pastes based on the mixture of silver nanoparticles and silver microflakes. The authors also show the technology of joining, justify their sintering parameters selection and compare their silver joints with Pb solder and adhesive. The joints prepared with pastes containing silver nanoparticles have much better electrical and thermal properties than the ones made with other techniques.

  4. Breast cancer survivors' decisions to join a dragon boating team.

    PubMed

    Weisenbach, Beth B; McDonough, Meghan H

    2014-12-01

    Physical activity is associated with psychosocial and physical health benefits for breast cancer survivors. Little is known, however, about survivors' decision-making processes when considering joining group physical activity programs designed for survivors. Guided by interpretive description methodology (Thorne, 2008), N = 15 breast cancer survivors who were considering or had made the decision to join a dragon boating team were interviewed about their decisions to participate. Four patterns of decision making were identified: searching for a way to care for physical and social needs, taking advantage of opportunities created by breast cancer, dove in with little contemplation, and hesitant to connect with other survivors. Results have implications for understanding decisions to participate in physical activity groups in this population and overcoming challenges to participation.

  5. Becoming stranger: When future selves join the out-group.

    PubMed

    Burum, Bethany A; Gilbert, Daniel T; Wilson, Timothy D

    2016-09-01

    One of the most powerful rules of interpersonal behavior is that people are kinder to members of their in-groups than to members of their out-groups. Are people also kinder to their future selves when they expect them to remain members of their current in-groups rather than become members of their current out-groups? In 2 studies, participants in an emotionally charged debate expected either to remain on the same team or to join the opposing team when they returned the following week. Those who expected to join the opposing team were less willing to sacrifice for their future selves, leaving more of an unpleasant task for their future selves to finish and treating their future selves as unkindly as they treated a stranger. These results suggest that the rules that govern interpersonal behavior may also govern intertemporal behavior, and suggest new strategies to encourage prudent decisions. (PsycINFO Database Record

  6. 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.

  7. Joining dissimilar materials using Friction Stir scribe technique

    SciTech Connect

    Upadhyay, Piyush; Hovanski, Yuri; Jana, Saumyadeep; Fifield, Leonard S.

    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 process 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.

  8. 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.

  9. Joining of ceramics of different biofunction by hot isostatic pressing

    SciTech Connect

    Li, Jianguo . Center for Dental Technology and Biomaterials); Harmansson, L. ); Soeremark, R. . Dept. of Prosthodontics)

    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 pressing process. It seems that ceramics with high green strength and similar green density are essential when joining ceramics by combined CIP and HIP processes.

  10. Low Temperature Active Joining of Structural and Electronic Composites

    DTIC Science & Technology

    2007-11-02

    vacuum pre-treating of stainless steel and t Materials Resources International 27 Aluminumg has and s g met Alloy n for also s trengt...solid aluminum Bond method was required. If Ti alloy or thi only joining methods can be used. The exa thermal vacuum pre-treatments, grit-blasting were...Rod/Rod tensile test results with Alloy 220 Figure 12. Joints shear strength for single lap shear Figure 13. Effect of doubling the joint

  11. Apparatus for the joining of ceramics using microwave hybrid heating

    SciTech Connect

    Cozzi, A.D.; Ferber, M.K.; Tennery, V.J.

    1995-12-31

    An apparatus was designed and constructed to facilitate the joining of ceramics in a microwave field. The microwave unit used is a modified Goldstar MA-1172M household microwave oven. The maximum load that can be applied is 2.24 kN. Temperature can be monitored with either a shielded type R thermocouple or an optical pyrometer. Measurements of the temperature and applied load are collected remotely.

  12. Fellow astronauts join Gemini 7 crew for preflight breakfast

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Fellow astronauts join the Gemini 7 prime crew for breakfeast in the Manned Spacecraft Operations Building, Merritt Island, on the day of the Gemini 7 launch. Clockwise around table, starting lower left, are Astronauts James A. Lovell Jr., Gemini 7 prime crew pilot; Walter M. Schirra Jr., Donald K. Slayton, MSC Assistant Director for Flight Crew Operations; Richard F. Gordon Jr., Gemini 8 backup crew pilot; Virgil I. Grissom, Charles Conrad Jr., and Frank Borman, Gemini 7 prime crew command pilot.

  13. 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

  14. 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.

  15. 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

  16. Consider the workhorse: Nonhomologous end joining in budding yeast

    PubMed Central

    Emerson, Charlene H.; Bertuch, Alison A.

    2017-01-01

    DNA double strand breaks (DSBs) are dangerous sources of genome instability and must be repaired by the cell. Nonhomologous end joining (NHEJ) is an evolutionarily conserved pathway to repair DSBs by direct ligation of the ends, with no requirement for a homologous template. While NHEJ is the primary DSB repair pathway in mammalian cells, conservation of the core NHEJ factors throughout eukaryotes make the pathway attractive for study in model organisms. The budding yeast, Saccharomyces cerevisiae, has been used extensively to develop a functional picture of NHEJ. In this review, we will discuss the current understanding of NHEJ in S. cerevisiae. Topics include canonical end-joining, alternative end-joining, and pathway regulation. Particular attention will be paid to the NHEJ mechanism involving core factors, including Yku70/80, Dnl4, Lif1, and Nej1, as well as the various factors implicated in the processing of the broken ends. The relevance of chromatin dynamics to NHEJ will also be discussed. This review illustrates the use of S. cerevisiae as a powerful system to understand the principles of NHEJ, as well as in pioneering the direction of the field. PMID:27240172

  17. DNA Polymerase θ: A Unique Multifunctional End-Joining Machine

    PubMed Central

    Black, Samuel J.; Kashkina, Ekaterina; Kent, Tatiana; Pomerantz, Richard T.

    2016-01-01

    The gene encoding DNA polymerase θ (Polθ) was discovered over ten years ago as having a role in suppressing genome instability in mammalian cells. Studies have now clearly documented an essential function for this unique A-family polymerase in the double-strand break (DSB) repair pathway alternative end-joining (alt-EJ), also known as microhomology-mediated end-joining (MMEJ), in metazoans. Biochemical and cellular studies show that Polθ exhibits a unique ability to perform alt-EJ and during this process the polymerase generates insertion mutations due to its robust terminal transferase activity which involves template-dependent and independent modes of DNA synthesis. Intriguingly, the POLQ gene also encodes for a conserved superfamily 2 Hel308-type ATP-dependent helicase domain which likely assists in alt-EJ and was reported to suppress homologous recombination (HR) via its anti-recombinase activity. Here, we review our current knowledge of Polθ-mediated end-joining, the specific activities of the polymerase and helicase domains, and put into perspective how this multifunctional enzyme promotes alt-EJ repair of DSBs formed during S and G2 cell cycle phases. PMID:27657134

  18. Analysis and optimization of recombinant DNA joining reactions.

    PubMed

    Legerski, R J; Robberson, D L

    1985-01-20

    The statistical segment length of duplex DNA was determined in phage T4 ligase (poly(deoxyribonucleotide): poly(deoxyribonucleotide) ligase (AMP forming), EC 6.5.1.1) buffer (50 mM-Tris . HCl (pH 7.8), 20 mM-dithiothreitol, 10 mM-MgCl2, 1 mM-ATP) at 12 degrees C to be 1030(+/- 116) A. This result was obtained by electron microscopic examination of the molecular distributions generated by T4 ligase-mediated joining of EcoRI-cleaved pBR322 DNA. This value of the statistical segment length was utilized in an extension of the Jacobson-Stockmayer theory on the probability of intramolecular cyclization in order to optimize DNA joining reactions that are of great utility in recombinant DNA experiments. Five cloning systems were analyzed: circular plasmid vectors that had been linearized with one or two restriction endonucleases, circular plasmids that had been tailed with deoxyhomopolymers before joining, lambda-type cloning vectors and cosmids. The results are tabulated for convenient use in molecular cloning experiments.

  19. Consider the workhorse: Nonhomologous end-joining in budding yeast.

    PubMed

    Emerson, Charlene H; Bertuch, Alison A

    2016-10-01

    DNA double strand breaks (DSBs) are dangerous sources of genome instability and must be repaired by the cell. Nonhomologous end-joining (NHEJ) is an evolutionarily conserved pathway to repair DSBs by direct ligation of the ends, with no requirement for a homologous template. While NHEJ is the primary DSB repair pathway in mammalian cells, conservation of the core NHEJ factors throughout eukaryotes makes the pathway attractive for study in model organisms. The budding yeast, Saccharomyces cerevisiae, has been used extensively to develop a functional picture of NHEJ. In this review, we will discuss the current understanding of NHEJ in S. cerevisiae. Topics include canonical end-joining, alternative end-joining, and pathway regulation. Particular attention will be paid to the NHEJ mechanism involving core factors, including Yku70/80, Dnl4, Lif1, and Nej1, as well as the various factors implicated in the processing of the broken ends. The relevance of chromatin dynamics to NHEJ will also be discussed. This review illustrates the use of S. cerevisiae as a powerful system to understand the principles of NHEJ, as well as in pioneering the direction of the field.

  20. Snacks in the Stacks: Libraries Welcome Food amid the Books

    ERIC Educational Resources Information Center

    Foster, Andrea L.

    2008-01-01

    Revitalization is what Morningside College had in mind in 2006, when it lifted a ban against eating in the library. That is when its library cafe, which opened a year earlier, began offering sandwiches and soups that could be carried into study areas and computer labs. Morningside has joined those that are casting aside their libraries' stuffy…

  1. Atom-economic catalytic amide synthesis from amines and carboxylic acids activated in situ with acetylenes

    PubMed Central

    Krause, Thilo; Baader, Sabrina; Erb, Benjamin; Gooßen, Lukas J.

    2016-01-01

    Amide bond-forming reactions are of tremendous significance in synthetic chemistry. Methodological research has, in the past, focused on efficiency and selectivity, and these have reached impressive levels. However, the unacceptable amounts of waste produced have led the ACS GCI Roundtable to label ‘amide bond formation avoiding poor atom economy' as the most pressing target for sustainable synthetic method development. In response to this acute demand, we herein disclose an efficient one-pot amide coupling protocol that is based on simple alkynes as coupling reagents: in the presence of a dichloro[(2,6,10-dodecatriene)-1,12-diyl]ruthenium catalyst, carboxylate salts of primary or secondary amines react with acetylene or ethoxyacetylene to vinyl ester intermediates, which undergo aminolysis to give the corresponding amides along only with volatile acetaldehyde or ethyl acetate, respectively. The new amide synthesis is broadly applicable to the synthesis of structurally diverse amides, including dipeptides. PMID:27282773

  2. Recent advances in copper-catalyzed C–H bond amidation

    PubMed Central

    Jing, Yanfeng

    2015-01-01

    Summary Copper catalysis has been known as a powerful tool for its ubiquitous application in organic synthesis. One of the fundamental utilities of copper catalysis is in the C–N bond formation by using carbon sources and nitrogen functional groups such as amides. In this review, the recent progress in the amidation reactions employing copper-catalyzed C–H amidation is summarized. PMID:26664644

  3. Advanced fusion welding processes, solid state joining and a successful marriage. [production of aerospace structures

    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.

  4. Inhibition of nociceptive responses after systemic administration of amidated kyotorphin

    PubMed Central

    Ribeiro, MMB; Pinto, A; Pinto, M; Heras, M; Martins, I; Correia, A; Bardaji, E; Tavares, I; Castanho, M

    2011-01-01

    BACKGROUND AND PURPOSE Kyotorphin (KTP; L-Tyr-L-Arg), an endogenous neuropeptide, is potently analgesic when delivered directly to the central nervous system. Its weak analgesic effects after systemic administration have been explained by inability to cross the blood–brain barrier (BBB) and detract from the possible clinical use of KTP as an analgesic. In this study, we aimed to increase the lipophilicity of KTP by amidation and to evaluate the analgesic efficacy of a new KTP derivative (KTP-amide – KTP-NH2). EXPERIMENTAL APPROACH We synthesized KTP-NH2. This peptide was given systemically to assess its ability to cross the BBB. A wide range of pain models, including acute, sustained and chronic inflammatory and neuropathic pain, were used to characterize analgesic efficacies of KTP-NH2. Binding to opioid receptors and toxicity were also measured. KEY RESULTS KTP-NH2, unlike its precursor KTP, was lipophilic and highly analgesic following systemic administration in several acute and chronic pain models, without inducing toxic effects or affecting motor responses and blood pressure. Binding to opioid receptors was minimal. KTP-NH2 inhibited nociceptive responses of spinal neurons. Its analgesic effects were prevented by intrathecal or i.p. administration of naloxone. CONCLUSIONS AND IMPLICATIONS Amidation allowed KTP to show good analgesic ability after systemic delivery in acute and chronic pain models. The indirect opioid-mediated actions of KTP-NH2 may explain why this compound retained its analgesic effects although the usual side effects of opioids were absent, which is a desired feature in next-generation pain medications. PMID:21366550

  5. 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... Join File Structure This is the structure of the data file to provide to the FDIC information necessary..., an indication that it is a join file type and the date of the extract. The files will be...

  6. 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... Join File Structure This is the structure of the data file to provide to the FDIC information necessary..., an indication that it is a join file type and the date of the extract. The files will be...

  7. 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... Join File Structure This is the structure of the data file to provide to the FDIC information necessary..., an indication that it is a join file type and the date of the extract. The files will be...

  8. 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... Join File Structure This is the structure of the data file to provide to the FDIC information necessary..., an indication that it is a join file type and the date of the extract. The files will be...

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

    NASA Technical Reports Server (NTRS)

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

    2015-01-01

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

  10. Antiproliferative activity of synthetic fatty acid amides from renewable resources.

    PubMed

    dos Santos, Daiane S; Piovesan, Luciana A; D'Oca, Caroline R Montes; Hack, Carolina R Lopes; Treptow, Tamara G M; Rodrigues, Marieli O; Vendramini-Costa, Débora B; Ruiz, Ana Lucia T G; de Carvalho, João Ernesto; D'Oca, Marcelo G Montes

    2015-01-15

    In the work, the in vitro antiproliferative activity of a series of synthetic fatty acid amides were investigated in seven cancer cell lines. The study revealed that most of the compounds showed antiproliferative activity against tested tumor cell lines, mainly on human glioma cells (U251) and human ovarian cancer cells with a multiple drug-resistant phenotype (NCI-ADR/RES). In addition, the fatty methyl benzylamide derived from ricinoleic acid (with the fatty acid obtained from castor oil, a renewable resource) showed a high selectivity with potent growth inhibition and cell death for the glioma cell line-the most aggressive CNS cancer.

  11. N-Hydroxyimide Ugi Reaction toward α-Hydrazino Amides

    PubMed Central

    2017-01-01

    The Ugi four-component reaction (U-4CR) with N-hydroxyimides as a novel carboxylic acid isostere has been reported. This reaction provides straightforward access to α-hydrazino amides. A broad range of aldehydes, amines, isocyanides and N-hydroxyimides were employed to give products in moderate to high yields. This reaction displays N–N bond formation by cyclic imide migration in the Ugi reaction. Thus, N-hydroxyimide is added as a new acid component in the Ugi reaction and broadens the scaffold diversity. PMID:28220702

  12. Isolation and identification of fatty acid amides from Shengli coal

    SciTech Connect

    Ming-Jie Ding; Zhi-Min Zong; Ying Zong; Xiao-Dong Ou-Yang; Yao-Guo Huang; Lei Zhou; Feng Wang; Jiang-Pei Cao; Xian-Yong Wei

    2008-07-15

    Shengli coal, a Chinese brown coal, was extracted with carbon disulfide and the extract was gradiently eluted with n-hexane and ethyl acetate (EA)/n-hexane mixed solvents with different concentrations of EA in a silica gel-filled column. A series of fatty acid amides, including fourteen alkanamides (C{sub 15}-C{sub 28}) and three alkenamides (C{sub 18} and C{sub 22}), were isolated from the coal by this method and analyzed with a gas chromatography/mass spectrometry. 26 refs., 2 figs., 2 tabs.

  13. Ultrapulse welding: A new joining technique. [for automotive industry

    NASA Technical Reports Server (NTRS)

    Anderson, D. G.

    1972-01-01

    The ultrapulse process is a resistance welding process that utilizes unidirectional current of high magnitude for a very short time with a precisely controlled dynamic force pulse. Peak currents of up to 220,000 amperes for two to ten milliseconds are used with synchronized force pulses of up to nine thousand pounds. The welding current passing through the relatively high resistance of the interface between the parts that are being joined results in highly localized heating. Described is the UPW process as it applies to the automotive industry.

  14. Method for joining metal by solid-state bonding

    DOEpatents

    Burkhart, L. Elkin; Fultz, Chester R.; Maulden, Kerry A.

    1979-01-01

    The present development is directed to a method for joining metal at relatively low temperatures by solid-state bonding. Planar surfaces of the metal workpieces are placed in a parallel abutting relationship with one another. A load is applied to at least one of the workpieces for forcing the workpieces together while one of the workpieces is relatively slowly oscillated in a rotary motion over a distance of about 1.degree.. After a preselected number of oscillations, the rotary motion is terminated and the bond between the abutting surfaces is effected. An additional load may be applied to facilitate the bond after terminating the rotary motion.

  15. Approaches for mechanical joining of 7xxx series aluminum alloys

    NASA Astrophysics Data System (ADS)

    Jäckel, M.; Grimm, T.; Landgrebe, D.

    2016-10-01

    This paper shows a numerical and experimental analysis of the different problems occurring during or after the conventional self-pierce riveting with semi-tubular and solid rivets of the high strength aluminum alloy EN AW-7021 T4. Furthermore this paper describes different pre-process methods by which the fracture in the high strength aluminum, caused by the self-pierce riveting processes, can be prevented and proper joining results are achieved. On this basis, the different approaches are compared regarding joint strength.

  16. Laser based metal and plastics joining for lightweight design

    NASA Astrophysics Data System (ADS)

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

    2015-03-01

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

  17. Metal-ceramic junctions - Mechanical and physicochemical interactive joining techniques

    NASA Astrophysics Data System (ADS)

    Lascar, Guy

    Reactive brazing and thermocompression are discussed in terms of their use as joining techniques for metal-ceramic structures. Theoretical consideration is given to brazing under vacuum conditions to examine the relationships between contact surface and volume, interfacial energy, surface energy, and adhesion energy. Brazing is shown to permit metal-ceramic junctions without metallization of the ceramic substrate, although several reactions and metallic materials can affect joint strength. Thermocompression is distinguished from brazing and shown to limit the alteration of the ceramic material. The protection of the mechanical properties of the ceramic and metal components of the materials is a critical aspect of industrial applications of brazing and thermocompression.

  18. 8. Several of the rental rooms are joined by doors, ...

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

    8. Several of the rental rooms are joined by doors, and each room is accessed from the corridor. Originally, the transoms were glazed. When a central heating/cooling system was installed, the transoms were modified to accommodate air grilles that are supplied by a duct located in the corridor. The five-panel door and wood wainscot are original features. However, the wainscot does not occur in every room. The lath and plaster partitions and the wood flooring are typical of the original construction. Credit GADA/MRM. - Stroud Building, 31-33 North Central Avenue, Phoenix, Maricopa County, AZ

  19. Method for joining carbon-carbon composites to metals

    DOEpatents

    Lauf, R.J.; McMillan, A.D.; Moorhead, A.J.

    1997-07-15

    A method for joining carbon-carbon composites to metals by brazing. Conventional brazing of recently developed carbon-bonded carbon fiber (CBCF) material to a metal substrate is limited by the tendency of the braze alloy to ``wick`` into the CBCF composite rather than to form a strong bond. The surface of the CBCF composite that is to be bonded is first sealed with a fairly dense carbonaceous layer achieved by any of several methods. The sealed surface is then brazed to the metal substrate by vacuum brazing with a Ti-Cu-Be alloy. 1 fig.

  20. Method for joining carbon-carbon composites to metals

    DOEpatents

    Lauf, Robert J.; McMillan, April D.; Moorhead, Arthur J.

    1997-01-01

    A method for joining carbon-carbon composites to metals by brazing. Conventional brazing of recently developed carbon-bonded carbon fiber (CBCF) material to a metal substrate is limited by the tendency of the braze alloy to "wick" into the CBCF composite rather than to form a strong bond. The surface of the CBCF composite that is to be bonded is first sealed with a fairly dense carbonaceous layer achieved by any of several methods. The sealed surface is then brazed to the metal substrate by vacuum brazing with a Ti-Cu-Be alloy.

  1. A new active solder for joining electronic components

    SciTech Connect

    SMITH,RONALD W.; VIANCO,PAUL T.; HERNANDEZ,CYNTHIA L.; LUGSCHEIDER,E.; RASS,I.; HILLEN,F.

    2000-05-11

    Electronic components and micro-sensors utilize ceramic substrates, copper and aluminum interconnect and silicon. The joining of these combinations require pre-metallization such that solders with fluxes can wet such combinations of metals and ceramics. The paper will present a new solder alloy that can bond metals, ceramics and composites. The alloy directly wets and bonds in air without the use flux or premetallized layers. The paper will present typical processing steps and joint microstructures in copper, aluminum, aluminum oxide, aluminum nitride, and silicon joints.

  2. Construction of Electrochemical Chiral Interfaces with Integrated Polysaccharides via Amidation.

    PubMed

    Bao, Liping; Chen, Xiaohui; Yang, Baozhu; Tao, Yongxin; Kong, Yong

    2016-08-24

    Polysaccharides of sodium carboxymethyl cellulose (CMC) and chitosan (CS) were integrated together via amidation reactions between the carboxyl groups on sodium CMC and the amino groups on CS. Compared with individual sodium CMC and CS, the integrated polysaccharides with a mass ratio of 1:1, CMC-CS (1:1), exhibited a three-dimensional (3D) porous network structure, resulting in a significantly enhanced hydrophility due to the exposed polar functional groups in the CMC-CS (1:1). Chiral interfaces were constructed with the integrated polysaccharides and used for electrochemical enantiorecognition of tryptophan (Trp) isomers. The CMC-CS (1:1) chiral interfaces exhibited excellent selectivity toward the Trp isomers owing to the highly hydrophilic feature of CMC-CS (1:1) and the different steric hindrance during the formation of H bonds between Trp isomers and CMC-CS (1:1). Also, the optimization in the preparation of integrated polysaccharides such as mass ratio and combination mode (amidation or electrostatic interactions) was investigated. The CMC-CS (1:1) presented the ability of determining the percentage of d-Trp in racemic mixtures, and thus, the proposed electrochemical chiral interfaces could be regarded as a potential biosensing platform for enantiorecognition of chiral compounds.

  3. Controlling Mechanical Properties of Bis-leucine Oxalyl Amide Gels

    NASA Astrophysics Data System (ADS)

    Chang, William; Carvajal, Daniel; Shull, Kenneth

    2011-03-01

    is-leucine oxalyl amide is a low molecular weight gelator capable of gelling polar and organic solvents. A fundamental understanding of self-assembled systems can lead to new methods in drug delivery and the design of new soft material systems. An important feature of self-assembled systems are the intermolecular forces between solvent and gelator molecule; by changing the environment the gel is in, the mechanical properties also change. In this project two variables were considered: the degree of neutralization present for the gelator molecule from neutral to completely ionized, and the concentration of the gelator molecule, from 1 weight percent to 8 weight percent in 1-butanol. Mechanical properties were studied using displacement controlled indentation techniques and temperature sweep rheometry. It has been found that properties such as the storage modulus, gelation temperature and maximum stress allowed increase with bis-leucine oxalyl amide concentration. The results from this study establish a 3-d contour map between the gelator concentration, the gelator degree of ionization and mechanical properties such as storage modulus and maximum stress allowed. The intermolecular forces between the bis-leucine low molecular weight gelator and 1-butanol govern the mechanical properties of the gel system, and understanding these interactions will be key to rationally designed self-assembled systems.

  4. Poly(ester amide)s based on (L)-lactic acid oligomers and α-amino acids: influence of the α-amino acid side chain in the poly(ester amide)s properties.

    PubMed

    Fonseca, Ana C; Coelho, Jorge F J; Valente, Joana F A; Correia, Tiago R; Correia, Ilídio J; Gil, Maria H; Simões, Pedro N

    2013-01-01

    Novel biodegradable and low cytotoxic poly(ester amide)s (PEAs) based on α-amino acids and (L)-lactic acid (L-LA) oligomers were successfully synthesized by interfacial polymerization. The chemical structure of the new polymers was confirmed by spectroscopic analyses. Further characterization suggests that the α-amino acid plays a critical role on the final properties of the PEA. L-phenylalanine provides PEAs with higher glass transition temperature, whereas glycine enhances the crystallinity. The hydrolytic degradation in PBS (pH = 7.4) at 37 °C also depends on the α-amino acid, being faster for glycine-based PEAs. The cytotoxic profiles using fibroblast human cells indicate that the PEAs did not elicit an acute cytotoxic effect. The strategy presented in this work opens the possibility of synthesizing biodegradable PEAs with low citotoxicity by an easy and fast method. It is worth to mention also that the properties of these materials can be fine-tuned only by changing the α-amino acid.

  5. Complexation of di-amides of dipicolinic acid with neodymium

    SciTech Connect

    Lapka, J.L.; Paulenova, A.

    2013-07-01

    Di-amides have undergone significant studies as possible ligands for use in the partitioning of trivalent minor actinides and lanthanides. The binding affinities of three isomeric ligands with neodymium in acetonitrile solution have been investigated. The stability constants of the metal-ligand complexes formed between different isomers of N,N'-diethyl-N,N'- ditolyl-di-picolinamide (EtTDPA) and trivalent neodymium in acetonitrile have been determined by spectrophotometric and calorimetric methods. Each isomer of EtTDPA has been found to be capable of forming three complexes with trivalent neodymium, Nd(EtTDPA), Nd(EtTDPA){sub 2}, and Nd(EtTDPA){sub 3}. Values from spectrophotometric and calorimetric titrations are within reasonable agreement with each other. The order of stability constants for each metal:ligand complex decreases in the order Et(m)TDPA > Et(p)TDPA > Et(o)TDPA. The obtained values are comparable to other di-amidic ligands obtained under similar system conditions and mirror previously obtained solvent extraction data for EtTDPA at low ionic strengths. (authors.

  6. Mechanistic Elucidation of Zirconium-Catalyzed Direct Amidation.

    PubMed

    Lundberg, Helena; Tinnis, Fredrik; Zhang, Jiji; Algarra, Andrés G; Himo, Fahmi; Adolfsson, Hans

    2017-02-15

    The mechanism of the zirconium-catalyzed condensation of carboxylic acids and amines for direct formation of amides was studied using kinetics, NMR spectroscopy, and DFT calculations. The reaction is found to be first order with respect to the catalyst and has a positive rate dependence on amine concentration. A negative rate dependence on carboxylic acid concentration is observed along with S-shaped kinetic profiles under certain conditions, which is consistent with the formation of reversible off-cycle species. Kinetic experiments using reaction progress kinetic analysis protocols demonstrate that inhibition of the catalyst by the amide product can be avoided using a high amine concentration. These insights led to the design of a reaction protocol with improved yields and a decrease in catalyst loading. NMR spectroscopy provides important details of the nature of the zirconium catalyst and serves as the starting point for a theoretical study of the catalytic cycle using DFT calculations. These studies indicate that a dinuclear zirconium species can catalyze the reaction with feasible energy barriers. The amine is proposed to perform a nucleophilic attack at a terminal η(2)-carboxylate ligand of the zirconium catalyst, followed by a C-O bond cleavage step, with an intermediate proton transfer from nitrogen to oxygen facilitated by an additional equivalent of amine. In addition, the DFT calculations reproduce experimentally observed effects on reaction rate, induced by electronically different substituents on the carboxylic acid.

  7. Collagen and component polypeptides: Low frequency and amide vibrations

    NASA Astrophysics Data System (ADS)

    Fontaine-Vive, F.; Merzel, F.; Johnson, M. R.; Kearley, G. J.

    2009-01-01

    Collagen is a fibrous protein, which exists widely in the human body. The biomechanical properties of collagen depend on its triple helix structure and the corresponding low frequency vibrations. We use first-principles, density functional theory methods and analytical force fields to investigate the molecular vibrations of a model collagen compound, the results being validated by comparison with published, inelastic neutron scattering data. The results from these atomistic simulations are used at higher frequency to study the Amide I and V vibrations and therefore the vibrational signature of secondary and tertiary structure formation. In addition to collagen, its component homopolymers, poly-glycine and poly-proline are also studied. The Amide V vibration of glycine is strongly modified in going from the single helix of poly-glycine II to the triple helix of collagen. The collagen models are hydrated and this work allows us to discuss the relative merits of density functional theory and force field methods when tackling complex, partially crystalline systems.

  8. [Activated Sludge Bacteria Transforming Cyanopyridines and Amides of Pyridinecarboxylic Acids].

    PubMed

    Demakov, V A; Vasil'ev, D M; Maksimova, Yu G; Pavlova, Yu A; Ovechkina, G V; Maksimov, A Yu

    2015-01-01

    Species diversity of bacteria from the activated sludge of Perm biological waste treatment facilities capable of transformation of cyanopyridines and amides of pyridinecarboxylic acids was investigated. Enrichment cultures in mineral media with 3-cyanopyridine as the sole carbon and nitrogen source were used to obtain 32 clones of gram-negative heterotrophic bacteria exhibiting moderate growth on solid and liquid media with 3- and 4-cyanopyridine. Sequencing of the 16S rRNA gene fragments revealed that the clones with homology of at least 99% belonged to the genera Acinetobacte, Alcaligenes, Delftia, Ochrobactrum, Pseudomonas, Stenotrophomonas, and Xanthobacter. PCR analysis showed that 13 out of 32 isolates contained the sequences (-1070 bp) homologous to the nitrilase genes reported previously in Alcaligenes faecalis JM3 (GenBank, D13419.1). Nine clones were capable of nitrile and amide transformation in minimal salt medium. Acinetobacter sp. 11 h and Alcaligenes sp. osv transformed 3-cyanopyridine to nicotinamide, while most of the clones possessed amidase activity (0.5 to 46.3 mmol/(g h) for acetamide and 0.1 to 5.6 mmol/(g h) for nicotinamide). Nicotinamide utilization by strain A. faecalis 2 was shown to result in excretion of a secondary metabolite, which was identified as dodecyl acrylate at 91% probability.

  9. Amides derived from heteroaromatic amines and selected steryl hemiesters.

    PubMed

    Bildziukevich, Uladzimir; Rárová, Lucie; Saman, David; Havlíček, Libor; Drašar, Pavel; Wimmer, Zdeněk

    2013-12-20

    The current interest of the team has been focused on investigation of novel amides with potential cytotoxicity. The presented series of compounds was synthesized from selected steryl hemiesters and heteroaromatic amines. The synthetic protocol was designed in a simple and economic way, and divided into several general methodologies applicable to the compounds synthesized. The cytotoxicity was tested on cells derived from human T-lymphoblastic leukemia, breast adenocarcinoma and cervical cancer, and compared with tests on normal human fibroblasts. Most of the lanosterol-based compounds (3-5 and 7-10) showed medium to good cytotoxicity, while only two derivatives of cholesterol (18 and 19) showed medium cytotoxicity on human T-lymphoblastic leukemia cell line. The compounds 8 and 9 displayed the reasonable cytotoxicity among this series of amides, tested on the cell lines of T-lymphoblastic leukemia [14.5±0.4 μM (8) and 18.5±3.9 μM (9)], breast adenocarcinoma [19.5±2.1 μM (8) and 23.1±4.0 μM (9)] and cervical cancer [24.8±5.3 μM (8) and 29.1±4.7 μM (9)]. Only the compound 8 was adequately less active on normal human fibroblasts (40.4±11.1 μM).

  10. Stability of caffeic acid phenethyl amide (CAPA) in rat plasma.

    PubMed

    Yang, John; Kerwin, Sean M; Bowman, Phillip D; Stavchansky, Salomon

    2012-05-01

    A validated C₁₈ reverse-phase HPLC method with UV detection at 320 nm was developed and used for the stability evaluation of caffeic acid phenethyl amide (CAPA) and caffeic acid phenethyl ester (CAPE) in rat plasma. CAPA is the amide derivative of CAPE, a naturally occurring polyphenolic compound that has been found to be active in a variety of biological pathways. CAPA has been shown to protect endothelial cells against hydrogen peroxide-induced oxidative stress to a similar degree to CAPE. CAPE has been reported to be rapidly hydrolyzed in rat plasma via esterase enzymes. CAPA is expected to display a longer half-life than CAPE by avoiding hydrolysis via plasma esterases. The stability of CAPA and CAPE in rat plasma was investigated at three temperatures. The half-lives for CAPA were found to be 41.5, 10 and 0.82 h at 25, 37 and 60 °C, respectively. The half-lives for CAPE were found to be 1.95, 0.35 and 0.13 h at 4, 25 and 37 °C, respectively. The energy of activation was found to be 22.1 kcal/mol for CAPA and 14.1 kcal/mol for CAPE. A more stable compound could potentially extend the beneficial effects of CAPE.

  11. Normal human oral keratinocytes demonstrate abnormal DNA end joining activity during replicative senescence.

    PubMed

    Kang, Mo K; Shin, Ki-Hyuk; Yip, Felix K; Park, No-Hee

    2005-04-01

    Repair of DNA double-strand breaks (DSBs) is critical for the maintenance of cellular genetic integrity. DSBs are repaired by cellular end joining activity, which could proceed with varying degrees of accuracy. Abnormal end joining may lead to an accumulation of mutations and contribute to genetic instability and cellular aging. In the present study, we compared the efficiency and accuracy of end joining activities in exponentially replicating and senescing normal human oral keratinocytes (NHOK). We developed an in vitro end joining assay utilizing a plasmid linearized with a unique EcoR I or EcoR V restriction site. The efficiency of end joining was determined by PCR with primers that could amplify the fragment containing the end joining site. The accuracy of end joining was assessed by determining whether the original EcoR I site was restored after end joining. Both replicating and senescing cultures of NHOK yielded a similar level of end joining efficiency, which was noted by the similar intensity of PCR amplification. However, the frequency of end joining errors was significantly elevated in NHOK during replicative senescence. Senescing NHOK could thus accumulate abnormal end joining products, which might contribute to cellular aging and cancer.

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

    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.

  13. Comparing Adhesive Bonding and LAMP Joining Technology in Case of Hybrid Material Combination

    NASA Astrophysics Data System (ADS)

    Markovits, T.; Bauernhuber, A.

    As plastics are utilized more and more frequently in our devices, it becomes necessary that they can be adequately joined to other materials, like metals. Bonding different materials was carried so far out primarily by adhesives, however, novel technologies, like laser assisted metal-plastic joining are showing benefits against current technologies. In the course of this study, the authors joined PMMA plastic to structural steel by adhesives and by laser assisted metal-plastic joining. Mechanical tests were carried out to compare the two different technologies, and to be able to position the LAMP joining within the field of joining technologies. Results show clearly the advantages of laser transmission joining as compared to adhesives.

  14. Ruthenium-catalyzed direct C-H amidation of arenes including weakly coordinating aromatic ketones.

    PubMed

    Kim, Jiyu; Kim, Jinwoo; Chang, Sukbok

    2013-06-03

    C-H activation: The ruthenium-catalyzed direct sp(2) C-H amidation of arenes by using sulfonyl azides as the amino source is presented (see scheme). A wide range of substrates were readily amidated including arenes bearing weakly coordinating groups. Synthetic utility of the thus obtained products was demonstrated in the preparation of biologically active heterocycles.

  15. 40 CFR 721.720 - Alkoxylated fatty acid amide, alkylsulfate salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., alkylsulfate salt. 721.720 Section 721.720 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.720 Alkoxylated fatty acid amide, alkylsulfate salt. (a) Chemical... as an alkoxylated fatty acid amide, alkylsulfate salt (PMN P-97-136) is subject to reporting...

  16. 40 CFR 721.720 - Alkoxylated fatty acid amide, alkylsulfate salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., alkylsulfate salt. 721.720 Section 721.720 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.720 Alkoxylated fatty acid amide, alkylsulfate salt. (a) Chemical... as an alkoxylated fatty acid amide, alkylsulfate salt (PMN P-97-136) is subject to reporting...

  17. 40 CFR 721.10063 - Halo substituted hydroxy nitrophenyl amide (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Halo substituted hydroxy nitrophenyl... Specific Chemical Substances § 721.10063 Halo substituted hydroxy nitrophenyl amide (generic). (a) Chemical... as halo substituted hydroxy nitrophenyl amide (PMN P-04-792) is subject to reporting under...

  18. 40 CFR 721.10192 - Amides, coco, N-[3-(dibutylamino)propyl], acrylates.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Amides, coco, N- , acrylates. 721.10192 Section 721.10192 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10192 Amides, coco, N-...

  19. 40 CFR 721.10191 - Amides, coco, N-[3-(dibutylamino)propyl].

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Amides, coco, N- . 721.10191 Section 721.10191 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT SIGNIFICANT NEW USES OF CHEMICAL SUBSTANCES Significant New Uses for Specific Chemical Substances § 721.10191 Amides, coco, N- . (a)...

  20. XtalFluor-E, an efficient coupling reagent for amidation of carboxylic acids.

    PubMed

    Orliac, Aurélie; Gomez Pardo, Domingo; Bombrun, Agnès; Cossy, Janine

    2013-02-15

    Amides were produced from carboxylic acids and amines by using XtalFluor-E as an activator. Even poorly reactive carboxylic acids can be transformed to amides. In addition, optically active amines and/or carboxylic acids were not epimerized/racemized during the process.

  1. A case study on the myth of emission from aliphatic amides

    NASA Astrophysics Data System (ADS)

    Singh, Avinash Kumar; Das, Sreyashi; Datta, Anindya

    2016-12-01

    For several decades, aliphatic amidic compounds have been believed to be emissive. We report that this contention is incorrect and that the anomalous emission from amides originates in fluorescent impurities generated during their synthesis. In order to make this point, we have synthesized fluorescent compounds and have compared the absorption spectra with excitation spectra.

  2. N-Acylbenzotriazoles: neutral acylating reagents for the preparation of primary, secondary, and tertiary amides

    PubMed

    Katritzky; He; Suzuki

    2000-12-01

    Readily available N-acylbenzotriazoles 2a-q efficiently acylate aqueous ammonia and primary and secondary amines to give primary, secondary, and tertiary amides in good to excellent yields. The wide applicability of the procedure is illustrated by the preparation of (i) alpha-hydroxyamides from alpha-hydroxy acids and of (ii) perfluoroalkylated amides.

  3. Palladium-catalyzed highly regioselective hydroaminocarbonylation of aromatic alkenes to branched amides.

    PubMed

    Zhu, Jinping; Gao, Bao; Huang, Hanmin

    2017-03-22

    Pd(t-Bu3P)2 has been successfully identified as an efficient catalyst for the hydroaminocarbonylation of aromatic alkenes to branched amides under relatively mild reaction conditions. With hydroxylamine hydrochloride as an additive, both aliphatic and aromatic amines could be used as coupling partners for the present reaction, leading to production of branched amides in high yields with excellent regioselectivities.

  4. 40 CFR 721.720 - Alkoxylated fatty acid amide, alkylsulfate salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., alkylsulfate salt. 721.720 Section 721.720 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.720 Alkoxylated fatty acid amide, alkylsulfate salt. (a) Chemical... as an alkoxylated fatty acid amide, alkylsulfate salt (PMN P-97-136) is subject to reporting...

  5. 40 CFR 721.720 - Alkoxylated fatty acid amide, alkylsulfate salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., alkylsulfate salt. 721.720 Section 721.720 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.720 Alkoxylated fatty acid amide, alkylsulfate salt. (a) Chemical... as an alkoxylated fatty acid amide, alkylsulfate salt (PMN P-97-136) is subject to reporting...

  6. 40 CFR 721.720 - Alkoxylated fatty acid amide, alkylsulfate salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., alkylsulfate salt. 721.720 Section 721.720 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... Specific Chemical Substances § 721.720 Alkoxylated fatty acid amide, alkylsulfate salt. (a) Chemical... as an alkoxylated fatty acid amide, alkylsulfate salt (PMN P-97-136) is subject to reporting...

  7. Iridium-catalyzed selective α-alkylation of unactivated amides with primary alcohols.

    PubMed

    Guo, Le; Liu, Yinghua; Yao, Wubing; Leng, Xuebing; Huang, Zheng

    2013-03-01

    The first α-alkylation of unactivated amides with primary alcohols is described. An effective and robust iridium pincer complex has been developed for selective α-alkylation of tertiary and secondary acetamides involving a "borrowing hydrogen" methodology. The method is compatible with alcohols bearing various functional groups. This presents a convenient and environmentally benign protocol for α-alkylation of amides.

  8. An azole, an amide and a limonoid from Vepris uguenensis (Rutaceae).

    PubMed

    Cheplogoi, Peter K; Mulholland, Dulcie A; Coombes, Philip H; Randrianarivelojosia, Milijaona

    2008-04-01

    The limonoid derivative, methyl uguenenoate, the azole, uguenenazole, and the amide, uguenenonamide, together with the known furoquinoline alkaloids flindersiamine and maculosidine, and syringaldehyde have been isolated from the root of the East African Rutaceae Vepris uguenensis. While methyl uguenenoate and the furoquinoline alkaloids displayed mild antimalarial activity, the azole and amide were completely inactive.

  9. Peroxide-mediated transition-metal-free direct amidation of alcohols with nitroarenes.

    PubMed

    Xiao, Fuhong; Liu, Yong; Tang, Chenglin; Deng, Guo-Jun

    2012-02-17

    An unusual direct amidation of alcohols with nitroarenes mediated by peroxides has been discovered. The reaction tolerated a wide range of functionalities, and various aromatic amides were obtained in moderate to good yields in the absence of transition-metal catalyst. The peroxides and solvents had a significant impact on the reaction yield.

  10. Surface plasmon resonance assisted rapid laser joining of glass

    SciTech Connect

    Zolotovskaya, Svetlana A.; Tang, Guang; Abdolvand, Amin; Wang, Zengbo

    2014-08-25

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

  11. Joining and Testing Composite Plates to Ti Tubes

    NASA Technical Reports Server (NTRS)

    Morscher, Gregory N.; Singh, Mrityunjay; Shpargei, Tarah; Asthana, Rajiv

    2005-01-01

    The joining of metal tubes to composite plates is required for heat-rejection components in several space applications. Currently a number of different braze compositions are being evaluated as to their effectiveness. Such tube-plate configurations cannot be represented by traditional methods of testing, e.g., lap joints. The joined region is not between two flat surfaces, but rather between a flat surface and a curved surface. Therefore, several tests have been employed to ascertain the effectiveness of the different braze approaches in tension that are both simple and representative of the actual system and relatively straightforward in analysis. The results of these "tube-tests" will be discussed for the three different braze compositions, Cu-ABA, Ti-Cu-Sil, and Ti-Cu-Ni. In addition, fracture analysis of the failed joints was performed and offers insights into the cause of joint failure and the distinctions which need to be made between the "strength" of a joint versus the "load carrying ability" of a joint.

  12. Development of the weld-braze joining process

    NASA Technical Reports Server (NTRS)

    Bales, T. T.; Royster, D. M.; Arnold, W. E., Jr.

    1973-01-01

    A joining process, designated weld-brazing, was developed which combines resistance spot welding and brazing. Resistance spot welding is used to position and aline the parts, as well as to establish a suitable faying-surface gap for brazing. Fabrication is then completed at elevated temperature by capillary flow of the braze alloy into the joint. The process was used successfully to fabricate Ti-6Al-4V alloy joints by using 3003 aluminum braze alloy and should be applicable to other metal-braze systems. Test results obtained on single-overlap and hat-stiffened panel specimens show that weld-brazed joints were superior in tensile shear, stress rupture, fatigue, and buckling compared with joints fabricated by conventional means. Another attractive feature of the process is that the brazed joint is hermetically sealed by the braze material, which may eliminate many of the sealing problems encountered with riveted or spot welded structures. The relative ease of fabrication associated with the weld-brazing process may make it cost effective over conventional joining techniques.

  13. Temperature Controlled Laser Joining of Aluminum to Galvanized Steel

    NASA Astrophysics Data System (ADS)

    Weller, Daniel; Simon, Jörg; Stritt, Peter; Weber, Rudolf; Graf, Thomas; Bezençon, Cyrille; Bassi, Corrado

    Reliable joining of 6000 series aluminum alloy to galvanized steel is a challenge for current manufacturing technologies. To control and limit the formation of brittle intermetallic phases, mixing of both metals in liquid state has to be avoided. It has been shown that laser weld-brazing is a possible process. Thereby the aluminum and zinc layer of the galvanized steel are molten and the steel remains solid during the process. In addition, to avoid zinc degassing, the aluminum melt bath temperature has to be below zinc boiling temperature of 907°C. To meet these requirements a temperature controlled laser process was developed, allowing to join the two materials without flux and filler material. The thickness of the intermetallic layer shows a dependency on the set temperature used to control the process. At optimum set temperature the thickness of intermetallic phases can be limited to about 5 μm. Tensile strengths of the joints of up to 75% of the aluminum base material were achieved.

  14. Welding of gold nanowires with different joining procedures

    NASA Astrophysics Data System (ADS)

    Guo, J. Y.; Xu, C. X.; Hu, A. M.; Shi, Z. L.; Sheng, F. Y.; Dai, J.; Li, Z. H.

    2012-02-01

    Welding of single-crystal metallic nanowires is likely to have an important role in the bottom-up fabrication of nanodevices. The welding effects of free ends of two single-crystal gold nanowires (Au-Au) were demonstrated by Monte Carlo simulations in this paper. The quantum corrected Sutton-Chen type many-body potential was used to model the metal-metal interactions. Metallic nanowires were first placed closely with head-to-head, head-to-side and side-to-side joining procedures. Two ends were successfully welded together to form a continuous nanowire by annealing at different temperatures. The welding effects of the different joining procedure with different temperatures were compared. Structures of the welded specimens were characterized by the common neighbor analysis technique. Variable atomic mobility, freedom and contacting angles may result in different bonding strengths in the three different configurations. The results showed that the joint structure welded at low temperature were similar to the cold welding without fusion meanwhile the molten phase was presented in the joint when processing at the high temperatures.

  15. Glass-ceramic joint and method of joining

    DOEpatents

    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.

  16. Positioning and joining of organic single-crystalline wires.

    PubMed

    Wu, Yuchen; Feng, Jiangang; Jiang, Xiangyu; Zhang, Zhen; Wang, Xuedong; Su, Bin; Jiang, Lei

    2015-03-27

    Organic single-crystal, one-dimensional materials can effectively carry charges and/or excitons due to their highly ordered molecule packing, minimized defects and eliminated grain boundaries. Controlling the alignment/position of organic single-crystal one-dimensional architectures would allow on-demand photon/electron transport, which is a prerequisite in waveguides and other optoelectronic applications. Here we report a guided physical vapour transport technique to control the growth, alignment and positioning of organic single-crystal wires with the guidance of pillar-structured substrates. Submicrometre-wide, hundreds of micrometres long, highly aligned, organic single-crystal wire arrays are generated. Furthermore, these organic single-crystal wires can be joined within controlled angles by varying the pillar geometries. Owing to the controllable growth of organic single-crystal one-dimensional architectures, we can present proof-of-principle demonstrations utilizing joined wires to allow optical waveguide through small radii of curvature (internal angles of ~90-120°). Our methodology may open a route to control the growth of organic single-crystal one-dimensional materials with potential applications in optoelectronics.

  17. Positioning and joining of organic single-crystalline wires

    PubMed Central

    Wu, Yuchen; Feng, Jiangang; Jiang, Xiangyu; Zhang, Zhen; Wang, Xuedong; Su, Bin; Jiang, Lei

    2015-01-01

    Organic single-crystal, one-dimensional materials can effectively carry charges and/or excitons due to their highly ordered molecule packing, minimized defects and eliminated grain boundaries. Controlling the alignment/position of organic single-crystal one-dimensional architectures would allow on-demand photon/electron transport, which is a prerequisite in waveguides and other optoelectronic applications. Here we report a guided physical vapour transport technique to control the growth, alignment and positioning of organic single-crystal wires with the guidance of pillar-structured substrates. Submicrometre-wide, hundreds of micrometres long, highly aligned, organic single-crystal wire arrays are generated. Furthermore, these organic single-crystal wires can be joined within controlled angles by varying the pillar geometries. Owing to the controllable growth of organic single-crystal one-dimensional architectures, we can present proof-of-principle demonstrations utilizing joined wires to allow optical waveguide through small radii of curvature (internal angles of ~90–120°). Our methodology may open a route to control the growth of organic single-crystal one-dimensional materials with potential applications in optoelectronics. PMID:25814032

  18. Fast acquisition of high resolution 4-D amide-amide NOESY with diagonal suppression, sparse sampling and FFT-CLEAN.

    PubMed

    Werner-Allen, Jon W; Coggins, Brian E; Zhou, Pei

    2010-05-01

    Amide-amide NOESY provides important distance constraints for calculating global folds of large proteins, especially integral membrane proteins with beta-barrel folds. Here, we describe a diagonal-suppressed 4-D NH-NH TROSY-NOESY-TROSY (ds-TNT) experiment for NMR studies of large proteins. The ds-TNT experiment employs a spin state selective transfer scheme that suppresses diagonal signals while providing TROSY optimization in all four dimensions. Active suppression of the strong diagonal peaks greatly reduces the dynamic range of observable signals, making this experiment particularly suitable for use with sparse sampling techniques. To demonstrate the utility of this method, we collected a high resolution 4-D ds-TNT spectrum of a 23kDa protein using randomized concentric shell sampling (RCSS), and we used FFT-CLEAN processing for further reduction of aliasing artifacts - the first application of these techniques to a NOESY experiment. A comparison of peak parameters in the high resolution 4-D dataset with those from a conventionally-sampled 3-D control spectrum shows an accurate reproduction of NOE crosspeaks in addition to a significant reduction in resonance overlap, which largely eliminates assignment ambiguity. Likewise, a comparison of 4-D peak intensities and volumes before and after application of the CLEAN procedure demonstrates that the reduction of aliasing artifacts by CLEAN does not systematically distort NMR signals.

  19. Synthesis and antimicrobial activity of amide derivatives of polyether antibiotic-salinomycin.

    PubMed

    Huczyński, Adam; Janczak, Jan; Stefańska, Joanna; Antoszczak, Michał; Brzezinski, Bogumil

    2012-07-15

    For the first time a direct and practical approach to the synthesis of eight amide derivatives of polyether antibiotic-salinomycin is described. The structure of allyl amide (3a) has been determined using X-ray diffraction. Salinomycin and its amide derivatives have been screened for their in vitro antimicrobial activity against the typical gram-positive cocci, gram-negative rods and yeast-like organisms, as well as against a series of clinical isolates of methicillin-resistant Staphylococcus aureus and methicillin-sensitive S. aureus. Amides of salinomycin have been found to show a wide range of activities, from inactive at 256 μg/mL to active with MIC of 2 μg/mL, comparable with salinomycin. As a result, phenyl amide (3b) was found to be the most active salinomycin derivative against gram-positive bacteria, MRSA and MSSA.

  20. Collective vibrational effects in hydrogen bonded liquid amides and proteins studied by isotopic substitution

    NASA Astrophysics Data System (ADS)

    Nielsen, O. F.; Johansson, C.; Christensen, D. H.; Hvidt, S.; Flink, J.; Høime Hansen, S.; Poulsen, F.

    2000-09-01

    Raman spectroscopy is used to study the fast dynamics of simple liquid amides and proteins. Raman spectra in the visible region of liquid amides are obtained with a triple additive scanning monochromator, whereas FT-Raman technique is used in the near-IR region in order to avoid fluorescence from impurities in the proteins. Raman spectra are shown in the amide-I region of HCONHCH 3 ( N-methylformamide with all isotopes in their natural abundance), H 13CONHCH 3, HC 18ONHCH 3, human growth hormone, frog tropomyosin and chymotrypsin inhibitor 2 including C-13 and N-15 enriched samples of the latter. Resonance energy transfer (RET) between amide molecules gives rise to a non-coincidence effect of the anisotropic and the isotropic components of the amide-I band. This effect influences the band position in mixtures of liquid amide isotopomers. A further spectral feature caused by collective vibrational modes in the hydrogen bonded liquid amides is named coalescence of bands in mixtures of isotopomers (CBMI). The result of this effect is that only one band is found in mixtures of isotopomers where bands at different frequencies are observed for each of the isotopomers. A similar effect may account for the observation of protein amide-I bands with frequencies dependent only on the secondary structure of the protein and not on the amino acid residues. RET and CBMI are due to a collectivity of vibrational modes in different amide molecules. This collectivity may be related to a cooperativity of hydrogen bonds. A low-frequency band around 100 cm -1 is observed in hydrogen bonded liquid amides and proteins. Isotopic substitution shows that the mode corresponding to this band involves displacements of atoms in hydrogen bonds. This mode may drive a breaking of the hydrogen bond.

  1. Effects of prefabricated hole structure on cold-pressing joining reliability between dissimilar sheets

    NASA Astrophysics Data System (ADS)

    Jin, Cheng Chuang; Li, Feng; Wang, Mo Nan; Bao, Ze Ping

    2016-12-01

    The structural form of prefabricated holes is one of the important factors to determine the quality and reliability of cold-pressing joining between dissimilar sheets. Different numbers of holes with the same area will lead to different wall thickness distributions and joining strengths. This paper takes the cold-pressing joining between AA1100 pure aluminum sheet and SS304 stainless steel sheet as an example, the further study results show that the end of aluminum sheet has an increasing tendency along the directions of length and width in the process of cold-pressing joining. The wall thickness of joints shows a symmetrical distribution on both sides and the joining thickness decreases from the center to both sides sequentially. With the continuous increase of the punch loading pressure, the average thinning ratio of the joints becomes larger. By contrast, when the other parameters are all the same, the joining strength is the most ideal when the punch loading pressure is 250 kN. The loading pressure which is too small or large is easy to cause an insufficient joining strength or defects. This paper provides a scientific basis in this aspect for optimizing the cold-pressing joining plan and designing a reasonable joint structure. It can also promote the existing cold-pressing joining technologies to be mature, and enrich the existing solid-state joining technology.

  2. Volume thermal expansion along the jadeite-diopside join

    NASA Astrophysics Data System (ADS)

    Pandolfo, Francesco; Cámara, Fernando; Domeneghetti, M. Chiara; Alvaro, Matteo; Nestola, Fabrizio; Karato, Shun-Ichiro; Amulele, George

    2015-01-01

    An in situ single-crystal high-temperature X-ray diffraction study was performed on clinopyroxene crystals along the jadeite, (NaAlSi2O6 Jd)-diopside (CaMgSi2O6 Di) join. In particular, natural samples of jadeite, diopside, P2/ n omphacite and three C2/ c synthetic samples with intermediate composition (i.e., Jd80, Jd60, Jd40) were investigated. In order to determine the unit-cell volume thermal expansion coefficient ( α V), the unit-cell parameters for all these compositions have been measured up to c.a. 1,073 K. The evolution of the unit-cell volume thermal expansion coefficient ( α V) along the Jd-Di join at different temperatures has been calculated by using a modified version of the equation proposed by Holland and Powell (J Metamorph Geol 16(3):309-343, 1998). The equation obtained from the α V at room- T (i.e., α V303K,1bar) allows us to predict the room- T volume thermal expansion for Fe-free C2/ c clinopyroxenes with intermediate composition along the binary join Jd-Di. The observed α V value for P2/ n omphacite α V(303K,1bar) = 2.58(5) × 10-5 K-1 was compared with that recalculated for disordered C2/ c omphacite published by Pandolfo et al. (Phys Chem Miner 1-10, 2012) [ α V(303K,1bar) = 2.4(5) × 10-5 K-1]. Despite the large e.s.d.'s for the latter, the difference of both values at room- T is small, indicating that convergent ordering has practically no influence on the room- T thermal expansion. However, at high- T, the smaller thermal expansion coefficient for the C2/c sample with respect to the P2/n one with identical composition could provide further evidence for its reduced stability relative to the ordered one.

  3. Lead Optimization Studies of Cinnamic Amide EP2 Antagonists

    PubMed Central

    2015-01-01

    Prostanoid receptor EP2 can play a proinflammatory role, exacerbating disease pathology in a variety of central nervous system and peripheral diseases. A highly selective EP2 antagonist could be useful as a drug to mitigate the inflammatory consequences of EP2 activation. We recently identified a cinnamic amide class of EP2 antagonists. The lead compound in this class (5d) displays anti-inflammatory and neuroprotective actions. However, this compound exhibited moderate selectivity to EP2 over the DP1 prostanoid receptor (∼10-fold) and low aqueous solubility. We now report compounds that display up to 180-fold selectivity against DP1 and up to 9-fold higher aqueous solubility than our previous lead. The newly developed compounds also display higher selectivity against EP4 and IP receptors and a comparable plasma pharmacokinetics. Thus, these compounds are useful for proof of concept studies in a variety of models where EP2 activation is playing a deleterious role. PMID:24773616

  4. Sulfonyl Fluoride Inhibitors of Fatty Acid Amide Hydrolase

    PubMed Central

    Alapafuja, Shakiru O.; Nikas, Spyros P.; Bharatan, Indu; Shukla, Vidyanand G.; Nasr, Mahmoud L.; Bowman, Anna L.; Zvonok, Nikolai; Li, Jing; Shi, Xiaomeng; Engen, John R.; Makriyannis, Alexandros

    2013-01-01

    Sulfonyl fluorides are known to inhibit esterases. Early work from our laboratory has identified hexadecyl sulfonylfluoride (AM374) as a potent in vitro and in vivo inhibitor of fatty acid amide hydrolase (FAAH). We now report on later generation sulfonyl fluoride analogs that exhibit potent and selective inhibition of FAAH. Using recombinant rat and human FAAH we show that 5-(4-hydroxyphenyl)pentanesulfonyl fluoride (AM3506) has similar inhibitory activity for both the rat and the human enzyme, while rapid dilution assays and mass spectrometry analysis suggest that the compound is a covalent modifier for FAAH and inhibits its action in an irreversible manner. Our SAR results are highlighted by molecular docking of key analogs. PMID:23083016

  5. pH adjustment schedule for the amide local anesthetics.

    PubMed

    Ikuta, P T; Raza, S M; Durrani, Z; Vasireddy, A R; Winnie, A P; Masters, R W

    1989-01-01

    Several studies have indicated that the addition of sodium bicarbonate to solutions of local anesthetics to raise the pH closer to the pKa shortens the latency, increases the intensity, and prolongs the duration of the resultant neural blockade. However, the addition of too much bicarbonate will cause precipitation, and this may result in the injection of particulate free base along with the solution. The present study was carried out to determine the maximal amount of sodium bicarbonate that can be added to each of the amide local anesthetics without the formation of a precipitate, and, thus, to construct a pH adjustment schedule to simplify the alkalinization of local anesthetics in clinical practice.

  6. Lead optimization studies of cinnamic amide EP2 antagonists.

    PubMed

    Ganesh, Thota; Jiang, Jianxiong; Yang, Myung-Soon; Dingledine, Ray

    2014-05-22

    Prostanoid receptor EP2 can play a proinflammatory role, exacerbating disease pathology in a variety of central nervous system and peripheral diseases. A highly selective EP2 antagonist could be useful as a drug to mitigate the inflammatory consequences of EP2 activation. We recently identified a cinnamic amide class of EP2 antagonists. The lead compound in this class (5d) displays anti-inflammatory and neuroprotective actions. However, this compound exhibited moderate selectivity to EP2 over the DP1 prostanoid receptor (∼10-fold) and low aqueous solubility. We now report compounds that display up to 180-fold selectivity against DP1 and up to 9-fold higher aqueous solubility than our previous lead. The newly developed compounds also display higher selectivity against EP4 and IP receptors and a comparable plasma pharmacokinetics. Thus, these compounds are useful for proof of concept studies in a variety of models where EP2 activation is playing a deleterious role.

  7. Polymer amide in the Allende and Murchison meteorites

    NASA Astrophysics Data System (ADS)

    McGeoch, Julie E. M.; McGeoch, Malcolm W.

    2015-12-01

    It has been proposed that exothermic gas phase polymerization of amino acids can occur in the conditions of a warm dense molecular cloud to form hydrophobic polymer amide (HPA) (McGeoch and McGeoch 2014). In a search for evidence of this presolar chemistry Allende and Murchison meteorites and a volcano control were diamond burr-etched and Folch extracted for potential HPA yielding 85 unique peaks in the meteorite samples via matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI TOF/MS). The amino acids after acid hydrolysis in Allende were below the level of detection but many of the Allende peaks via the more sensitive MALDI/TOF analysis could be fitted to a polymer combination of glycine, alanine, and alpha-hydroxyglycine with high statistical significance. A similar significant fit using these three amino acids could not be applied to the Murchison data indicating more complex polymer chemistry.

  8. Joining the nursing profession in Qatar: motives and perceptions.

    PubMed

    Okasha, M S; Ziady, H H

    2001-11-01

    We aimed to identify why female students in Qatar decide to become nurses and how the students perceived the community attitude towards nursing. A self-administered anonymous questionnaire was distributed to all (57) female students of the four academic classes of the Nursing Unit, University of Qatar for the academic year 1999-2000. The two commonest reasons for joining the nursing profession were an interest in medical services and the humanitarian nature of nursing. There were 33 (57.89%) students who considered there was a negative community attitude towards nursing mainly due to the presence of male patients and colleagues and the working hours. A mass media campaign and govemmental support were two strategies suggested to change this.

  9. Joining lead wires to thin platinum alloy films

    NASA Technical Reports Server (NTRS)

    Przybyszewski, J. S.; Claing, R. G. (Inventor)

    1983-01-01

    A two step process of joining a lead wire to .000002 m thick platinum alloy film which rests upon an equally thin alumina insulating layer which is adhered to a metal substrate is described. Typically the platinum alloy film forms part of a thermocouple for measuring the surface temperature of a gas turbine airfoil. In the first step the lead wire is deformed 30 to 60% at room temperature while the characteristic one million ohm resistance of the alumina insulating layer is monitored for degradation. In the second step the cold pressed assembly is heated at 865 to 1025 C for 4 to 75 hr in air. During the heating step any degradation of insulating layer resistance may be reversed, provided the resistance was not decreased below 100 ohm in the cold pressing.

  10. The endless tale of non-homologous end-joining.

    PubMed

    Weterings, Eric; Chen, David J

    2008-01-01

    DNA double-strand breaks (DSBs) are introduced in cells by ionizing radiation and reactive oxygen species. In addition, they are commonly generated during V(D)J recombination, an essential aspect of the developing immune system. Failure to effectively repair these DSBs can result in chromosome breakage, cell death, onset of cancer, and defects in the immune system of higher vertebrates. Fortunately, all mammalian cells possess two enzymatic pathways that mediate the repair of DSBs: homologous recombination and non-homologous end-joining (NHEJ). The NHEJ process utilizes enzymes that capture both ends of the broken DNA molecule, bring them together in a synaptic DNA-protein complex, and finally repair the DNA break. In this review, all the known enzymes that play a role in the NHEJ process are discussed and a working model for the co-operation of these enzymes during DSB repair is presented.

  11. Resistance Distances and Kirchhoff Index in Generalised Join Graphs

    NASA Astrophysics Data System (ADS)

    Chen, Haiyan

    2017-03-01

    The resistance distance between any two vertices of a connected graph is defined as the effective resistance between them in the electrical network constructed from the graph by replacing each edge with a unit resistor. The Kirchhoff index of a graph is defined as the sum of all the resistance distances between any pair of vertices of the graph. Let G=H[G1, G2, …, Gk ] be the generalised join graph of G1, G2, …, Gk determined by H. In this paper, we first give formulae for resistance distances and Kirchhoff index of G in terms of parameters of {G'_i}s and H. Then, we show that computing resistance distances and Kirchhoff index of G can be decomposed into simpler ones. Finally, we obtain explicit formulae for resistance distances and Kirchhoff index of G when {G'_i}s and H take some special graphs, such as the complete graph, the path, and the cycle.

  12. Joining of Silicon Carbide Through the Diffusion Bonding Approach

    NASA Technical Reports Server (NTRS)

    Halbig, Michael .; Singh, Mrityunjay

    2009-01-01

    In order for ceramics to be fully utilized as components for high-temperature and structural applications, joining and integration methods are needed. Such methods will allow for the fabrication the complex shapes and also allow for insertion of the ceramic component into a system that may have different adjacent materials. Monolithic silicon carbide (SiC) is a ceramic material of focus due to its high temperature strength and stability. Titanium foils were used as an interlayer to form diffusion bonds between chemical vapor deposited (CVD) SiC ceramics with the aid of hot pressing. The influence of such variables as interlayer thickness and processing time were investigated to see which conditions contributed to bonds that were well adhered and crack free. Optical microscopy, scanning electron microscopy, and electron microprobe analysis were used to characterize the bonds and to identify the reaction formed phases.

  13. Bridging the gaps : joining information sources with Splunk.

    SciTech Connect

    Lord, Kenneth Malcolm; Corwell, Sophia E.; Stearley, Jon R.

    2010-07-01

    Supercomputers are composed of many diverse components, operated at a variety of scales, and function as a coherent whole. The resulting logs are thus diverse in format, interrelated at multiple scales, and provide evidence of faults across subsystems. When combined with system configuration information, insights on both the downstream effects and upstream causes of events can be determined. However, difficulties in joining the data and expressing complex queries slow the speed at which actionable insights can be obtained. Effectively connecting data experts and data miners faces similar hurdles. This paper describes our experience with applying the Splunk log analysis tool as a vehicle to combine both data, and people. Splunk's search language, lookups, macros, and subsearches reduce hours of tedium to seconds of simplicity, and its tags, saved searches, and dashboards offer both operational insights and collaborative vehicles.

  14. Bridging the gaps : joining information sources with Splunk.

    SciTech Connect

    Lord, Kenneth Malcolm; Corwell, Sophia E.; Stearley, Jon R.

    2010-10-01

    Supercomputers are composed of many diverse components, operated at a variety of scales, and function as a coherent whole. The resulting logs are thus diverse in format, interrelated at multiple scales, and provide evidence of faults across subsystems. When combined with system configuration information, insights on both the downstream effects and upstream causes of events can be determined. However, difficulties in joining the data and expressing complex queries slow the speed at which actionable insights can be obtained. Effectively connecting data experts and data miners faces similar hurdles. This paper describes our experience with applying the Splunk log analysis tool as a vehicle to combine both data, and people. Splunk's search language, lookups, macros, and subsearches reduce hours of tedium to seconds of simplicity, and its tags, saved searches, and dashboards offer both operational insights and collaborative vehicles.

  15. Analysis of Gene Targeting & Nonhomologous End-joining. Final Report

    SciTech Connect

    Haber, J. E.

    2002-11-30

    Overall, we identified a number of new proteins that participate in nonhomologous end-joining and also in telomere addition to the ends of broken chromosomes. We showed that NHEJ is severely reduced in cells expressing both yeast mating-type genes and then went on to identify the NEJ1 gene that was under this control. We showed the epistasis relations among a set of mutations that impair telomere addition and we showed that there are in fact two pathways to repair broken chromosomes in the absence of telomerase. We characterized the DNA damage checkpoint pathway in response to a single broken chromosome and characterized especially the adaptation of cells arrested by an unrepaired DSB. We demonstrated that the DNA damage response is nuclear-limited. We showed adaptation defects for Tid1and Srs2 proteins and showed that Srs2 was also recovery-defective, even when DNA was repaired.

  16. Joining veneers to ceramic cores and dentition with adhesive interlayers.

    PubMed

    Lee, J J-W; Wang, Y; Lloyd, I K; Lawn, B R

    2007-08-01

    Adhesive joining of veneers to cores offers potential simplicity and economy in the fabrication of all-ceramic crowns. We tested the hypothesis that resin-based adhesives can be used for such fabrication without compromising mechanical integrity of the crown structure. A simple test procedure for quantifying this hypothesis was proposed. A model glass veneer layer 1 mm thick (representative of porcelain), adhesively bonded onto a glass-like core substrate (ceramic or dental enamel), was loaded at its top surface with a hard sphere (occlusal force) until a radial crack initiated at the veneer undersurface. The critical loads for fracture, visually observable in the transparent glass, afforded a measure of the predisposition for the adhesive to cause veneer failure in an occlusal overload. Two adhesives were tested, one a commercial epoxy resin and the other a relatively stiff in-house-developed composite. The results confirmed that stiffer adhesives provide higher resistance to failure.

  17. A transient FGM interlayer based approach to joining ceramics

    SciTech Connect

    Glaeser, A.M.; Shalz, M.L.; Dalgleish, B.J.; Tomsia, A.P.

    1993-01-01

    In most cases, functionally gradient materials have been designed to produce a desirable property gradient in a material or in a joint region. In this paper, the concept of a transient gradient structure is introduced. The function of the intentional property discontinuities in these multilayer interlayers is to facilitate processing of assemblies and materials combinations that would be difficult to process using conventional bonding approaches. Specifically, the methods make use of a thin or partial layer of a low melting point transient liquid phase to facilitate bonding via brazing, yet produce refractory joints. Several mechanisms for consuming the transient liquid former are outlined, and examples of interlayer designs that exploit these mechanisms are presented. Specific results from experiments joining alumina to alumina via Cu/Pt/Cu, Cu/Ni/Cu, Cu/Nb/Cu and Sn/Nb/Sn interlayers are presented.

  18. Joining problems posed by the development of materials

    NASA Astrophysics Data System (ADS)

    Colombie, M.

    A review of new materials is conducted to examine joining difficulties caused by the properties of the advanced materials. Attention is given to recent developments in the areas of polymers, ceramics, composite materials, and metal alloys. Fabrication procedures are outlined for traditional metals including continuous methods, and associated levels of purity are described that can be achieved with traditional materials such as steel. Recently developed materials discussed include 'multimaterials' such as Al alloys and polymer composites as well as the metallurgical techniques developed for their fabrication. The production of metal/ceramic combinations by means of diffusion bonding and welding is shown to require development, and fabrication methods are required that insure the production of reproducible and consistent materials.

  19. Pulsed Joining Of Body-In-White Components

    SciTech Connect

    Bonnen, John

    2014-09-30

    The objective of this project was to develop cost efficient high quality pulsed welding (PW) technology for joining 6xxx Aluminum and High Strength Steel (with tensile strength above 580MPa) components enabling broad usage of hydroformed parts and leading to substantial weight reduction of cars and trucks to reduce US demand on petroleum, lower carbon emissions and energy expenditures. In general, pulsed welding is a form of impact welding where two dissimilar metal pieces are joined by accelerating one to velocities exceeding 300m/s at which point the first piece strikes the second and forms a weld. In this work, two methods were used to accelerate the flyer material: Electro-Magnetic (EM) pulse and Electro-Hydraulic (EH) pulse launching. The advantage of pulsed welding techniques is that welds can be formed between two materials that cannot otherwise be welded: high strength aluminum and high strength steel. The technical objectives of the project included: 1) developing cost affordable production feasible tooling design for PW of 6xxx aluminum to High Strength steel with strengths above 580MPa; 2) demonstrating that fabricated joints can exceed the required service load strength initially at the coupon level and then at the component level; 3) developing fundamental understanding of the mechanisms of joint formation and conditions leading to formation of high quality PW joint; and 4) creating a numerical model predicting the tooling and electric discharge parameters necessary for the joint formation and that satisfy the targeted strength parameters. The project successfully developed: 1) EM and EH pulsed welds between high strength aluminum with tensile strengths exceeding 240MPa and steels exceeding 580MPa; 2) pulsed welds of extrusions with strengths exceeding project requirements; 3) EM and EH flyer launch models and 4) weld interface formation models. However, the grant holder, Ford Motor Company, could see no path to commercialization and the work was

  20. Synthesis of novel naphthoquinone aliphatic amides and esters and their anticancer evaluation.

    PubMed

    Kongkathip, Boonsong; Akkarasamiyo, Sunisa; Hasitapan, Komkrit; Sittikul, Pichamon; Boonyalai, Nonlawat; Kongkathip, Ngampong

    2013-02-01

    Fourteen new naphthoquinone aliphatic amides and seventeen naphthoquinone aliphatic esters were synthesized in nine to ten steps from 1-hydroxy-2-naphthoic acid with 9-25% overall yield for the amides, and 16-21% overall yield for the esters. The key step of the amide synthesis is a coupling reaction between amine and various aliphatic acids using 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM) as a coupling agent while for the ester synthesis, DCC/DMAP or CDI was used as the coupling reagent between aliphatic acids and naphthoquinone alcohol. Both naphthoquinone amides and esters were evaluated for their anticancer activity against KB cells. It was found that naphthoquinone aliphatic amides showed stronger anticancer activity than those of the esters when the chains are longer than 7-carbon atoms. The optimum chain of amides is expected to be 16-carbon atoms. In addition, naphthoquinone aliphatic esters with α-methyl on the ester moiety possessed much stronger anticancer activity than the straight chains. Decatenation assay revealed that naphthoquinone amide with 16-carbon atoms chain at 15 μM and 20 μM can completely inhibit hTopoIIα activity while at 10 μM the enzyme activity was moderately inhibited. Molecular docking result also showed the same trend as the cytotoxicity and decatenation assay.

  1. Joining of ceramics and ceramic matrix composites via reactive metal penetration

    NASA Astrophysics Data System (ADS)

    Locatelli, Mark Rico

    The processing and properties of ceramic and ceramic matrix composite components have improved to the point that they are now candidates for use in a variety of structural applications at high temperature. However, the lack of effective joining techniques limits further application of these materials. In an effort to remove this limitation a joining process based on the reactive metal penetration process used to make bulk metal/ceramic composites has been developed to join ceramics. This joining technique offers the potential to bond refractory components at reduced temperature, thus alleviating some of the limitations of traditional ceramic joining processes. Several experiments joining alumina and SiCf/SiC composite have been carried out at temperatures of 1100--1200°C. The results of these experiments show that processing ceramic joints with composite interlayers at these temperatures is possible, and may be technologically significant if a number of interesting processing and microstructural difficulties can be successfully overcome.

  2. 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.

  3. New synthesis route for ternary transition metal amides as well as ultrafast amide-hydride hydrogen storage materials.

    PubMed

    Cao, Hujun; Santoru, Antonio; Pistidda, Claudio; Richter, Theresia M M; Chaudhary, Anna-Lisa; Gizer, Gökhan; Niewa, Rainer; Chen, Ping; Klassen, Thomas; Dornheim, Martin

    2016-04-14

    K2[Mn(NH2)4] and K2[Zn(NH2)4] were successfully synthesized via a mechanochemical method. The mixture of K2[Mn(NH2)4] and LiH showed excellent rehydrogenation properties. In fact, after dehydrogenation K2[Mn(NH2)4]-8LiH fully rehydrogenates within 60 seconds at ca. 230 °C and 5 MPa of H2. This is one of the fastest rehydrogenation rates in amide-hydride systems known to date. This work also shows a strategy for the synthesis of transition metal nitrides by decomposition of the mixtures of M[M'(NH2)n] (where M is an alkali or alkaline earth metal and M' is a transition metal) and metal hydrides.

  4. Acceleration of Amide Bond Rotation by Encapsulation in the Hydrophobic Interior of a Water-Soluble Supramolecular Assembly

    SciTech Connect

    Pluth, Michael D.; Bergman, Robert G.; Raymond, Kenneth N.

    2008-04-08

    The hydrophobic interior cavity of a self-assembled supramolecular assembly exploits the hydrophobic effect for the encapsulation of tertiary amides. Variable temperature 1H NMR experiments reveal that the free energy barrier for rotation around the C-N amide bond is lowered by up to 3.6 kcal/mol upon encapsulation. The hydrophobic cavity of the assembly is able to stabilize the less polar transition state of the amide rotation process. Carbon-13 labeling studies showed that the {sup 13}C NMR carbonyl resonance increases with temperature for the encapsulated amides which suggests that the assembly is able to favor a twisted for of the amide.

  5. Probing the production of amidated peptides following genetic and dietary copper manipulations.

    PubMed

    Yin, Ping; Bousquet-Moore, Danielle; Annangudi, Suresh P; Southey, Bruce R; Mains, Richard E; Eipper, Betty A; Sweedler, Jonathan V

    2011-01-01

    Amidated neuropeptides play essential roles throughout the nervous and endocrine systems. Mice lacking peptidylglycine α-amidating monooxygenase (PAM), the only enzyme capable of producing amidated peptides, are not viable. In the amidation reaction, the reactant (glycine-extended peptide) is converted into a reaction intermediate (hydroxyglycine-extended peptide) by the copper-dependent peptidylglycine-α-hydroxylating monooxygenase (PHM) domain of PAM. The hydroxyglycine-extended peptide is then converted into amidated product by the peptidyl-α-hydroxyglycine α-amidating lyase (PAL) domain of PAM. PHM and PAL are stitched together in vertebrates, but separated in some invertebrates such as Drosophila and Hydra. In addition to its luminal catalytic domains, PAM includes a cytosolic domain that can enter the nucleus following release from the membrane by γ-secretase. In this work, several glycine- and hydroxyglycine-extended peptides as well as amidated peptides were qualitatively and quantitatively assessed from pituitaries of wild-type mice and mice with a single copy of the Pam gene (PAM(+/-)) via liquid chromatography-mass spectrometry-based methods. We provide the first evidence for the presence of a peptidyl-α-hydroxyglycine in vivo, indicating that the reaction intermediate becomes free and is not handed directly from PHM to PAL in vertebrates. Wild-type mice fed a copper deficient diet and PAM(+/-) mice exhibit similar behavioral deficits. While glycine-extended reaction intermediates accumulated in the PAM(+/-) mice and reflected dietary copper availability, amidated products were far more prevalent under the conditions examined, suggesting that the behavioral deficits observed do not simply reflect a lack of amidated peptides.

  6. Electronic circular dichroism of the chiral rigid tricyclic dilactam with nonplanar tertiary amide groups.

    PubMed

    Pazderková, Markéta; Profant, Václav; Seidlerová, Beata; Dlouhá, Helena; Hodačová, Jana; Jávorfi, Tamás; Siligardi, Giuliano; Baumruk, Vladimír; Bednárová, Lucie; Maloň, Petr

    2014-09-25

    Electronic circular dichroism (ECD) of the spirocyclic dilactam 5,8-diazatricyclo[6,3,0,0(1,5)]undecane-4,9-dione has been measured in the extended wavelength range (170-260 nm) utilizing far-UV CD instrumentation including synchrotron radiation light source. The data of this model of two nonplanar tertiary amide groups interacting within the rigid chiral environment provided new information particularly about the shorter wavelength π-π* transition region below 190 nm. The interpretation using TDDFT calculations confirmed that effects of amide nonplanarity follow our previous observations on monolactams as far as amide n-π* transitions are concerned. ECD band in the n-π* transition region of the nonplanar diamide exhibits an identical bathochromic shift and its sign remains tied to the sense of nonplanar deformation in the same way. As far as n-π* transitions are concerned amide nonplanarity acts as a local phenomenon independently reflecting sum properties of single amide groups. On the other hand, CD bands associated with π-π* transitions (found between ∼170 to 210 nm) form an exciton-like couplet with the sign pattern determined by mutual orientation of the associated electric transition moments. This sign pattern follows predictions pertaining to a coupled oscillator. The influence of amide nonplanarity on π-π* transitions is only minor and concentrates into the shorter wavelength lobe of the π-π* couplet. The detailed analysis of experimental ECD with the aid of TDDFT calculations shows that there is only little interaction between effects of inherent chirality caused by nonplanarity of amide groups and amide-amide coupling. Consequently these two effects can be studied nearly independently using ECD. In addition, the calculations indicate that participation of other type of transitions (n-σ*, π-σ* or Rydberg type transitions) is only minor and is concentrated below 180 nm.

  7. Integrated Conceptual Design of Joined-Wing SensorCraft Using Response Surface Models

    DTIC Science & Technology

    2006-11-01

    element and wind tunnel analysis of the joined- wing concept. He detailed several distinct advantages of a joined- wing configuration over a more...optimized” joined- wing and geometric perturbations of that model. Following Wolkovich, Smith, Cliff and Stonum performed calculations and wind tunnel ...location at 60 percent of the fore wing semispan. Wind tunnel data confirmed the design predictions for reduced bending moment on the forward wing , and a

  8. Chelate effects in sulfate binding by amide/urea-based ligands.

    PubMed

    Jia, Chuandong; Wang, Qi-Qiang; Begum, Rowshan Ara; Day, Victor W; Bowman-James, Kristin

    2015-07-07

    The influence of chelate and mini-chelate effects on sulfate binding was explored for six amide-, amide/amine-, urea-, and urea/amine-based ligands. Two of the urea-based hosts were selective for SO4(2-) in water-mixed DMSO-d6 systems. Results indicated that the mini-chelate effect provided by a single urea group with two NH binding sites appears to provide enhanced binding over two amide groups. Furthermore, additional urea binding sites incorporated into the host framework appeared to overcome to some extent competing hydration effects with increasing water content.

  9. Chemo- and Stereoselective Transition-Metal-Free Amination of Amides with Azides

    PubMed Central

    2016-01-01

    The synthesis of α-amino carbonyl/carboxyl compounds is a contemporary challenge in organic synthesis. Herein, we present a stereoselective α-amination of amides employing simple azides that proceeds under mild conditions with release of nitrogen gas. The amide is used as the limiting reagent, and through simple variation of the azide pattern, various differently substituted aminated products can be obtained. The reaction is fully chemoselective for amides even in the presence of esters or ketones and lends itself to preparation of optically enriched products. PMID:27350334

  10. Ruthenium(II)-Catalyzed Regioselective Ortho Amidation of Imidazo Heterocycles with Isocyanates.

    PubMed

    Shakoor, S M Abdul; Kumari, Santosh; Khullar, Sadhika; Mandal, Sanjay K; Kumar, Anil; Sakhuja, Rajeev

    2016-12-16

    Direct ortho amidation at the phenyl ring of 2-phenylimidazo heterocycles with aryl isocyanates has been achieved via a chelation-assisted cationic ruthenium(II) complex catalyzed mechanism. The methodology provides a straightforward, high-yielding regioselective approach toward the synthesis of an array of ortho-amidated phenylimidazo heterocycles without prior activation of C(sp(2))-H. This also reports the first method for coupling of aryl isocyanates with the imidazo[1,2-a]pyridine system via a pentacyclometalated intermediate. The methodology is found to be easily scalable and could be applied toward the selective ortho amidation of 2-heteroarylimidazo[1,2-a]pyridine frameworks.

  11. Efficient string similarity join in multi-core and distributed systems

    PubMed Central

    Yan, Cairong; Zhao, Xue; Zhang, Qinglong; Huang, Yongfeng

    2017-01-01

    In big data area a significant challenge about string similarity join is to find all similar pairs more efficiently. In this paper, we propose a parallel processing framework for efficient string similarity join. First, the input is split into some disjoint small subsets according to the joint frequency distribution and the interval distribution of strings. Then the filter-verification strategy is adopted in the computation of string similarity for each subset so that the number of candidate pairs is reduced before an effective pruning strategy is used to improve the performance. Finally, the operation of string join is executed in parallel. Para-Join algorithm based on the multi-threading technique is proposed to implement the framework in a multi-core system while Pada-Join algorithm based on Spark platform is proposed to implement the framework in a cluster system. We prove that Para-Join and Pada-Join cannot only avoid reduplicate computation but also ensure the completeness of the result. Experimental results show that Para-Join can achieve high efficiency and significantly outperform than state-of-the-art approaches, meanwhile, Pada-Join can work on large datasets. PMID:28278177

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

    SciTech Connect

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

    2005-02-09

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

  13. Joining of Ion Transport Membranes Using a Novel Transient Liquid Phase Process

    SciTech Connect

    Darryl P. Butt

    2006-08-30

    The feasibility of a novel transient liquid phase (TLP) joining method has been demonstrated in joining La{sub 0.9}Ca{sub 0.1}FeO{sub 3} materials. Metal oxide powders were processed to form the TLP compositions which were used in the joining process. The method has been successful in producing joint interfaces that effectively disappear, as they are the same material and have the same properties as the joined parts. The feasibility of the method has been demonstrated for a single system, but many systems where the method can potentially be applied have been identified.

  14. Efficient string similarity join in multi-core and distributed systems.

    PubMed

    Yan, Cairong; Zhao, Xue; Zhang, Qinglong; Huang, Yongfeng

    2017-01-01

    In big data area a significant challenge about string similarity join is to find all similar pairs more efficiently. In this paper, we propose a parallel processing framework for efficient string similarity join. First, the input is split into some disjoint small subsets according to the joint frequency distribution and the interval distribution of strings. Then the filter-verification strategy is adopted in the computation of string similarity for each subset so that the number of candidate pairs is reduced before an effective pruning strategy is used to improve the performance. Finally, the operation of string join is executed in parallel. Para-Join algorithm based on the multi-threading technique is proposed to implement the framework in a multi-core system while Pada-Join algorithm based on Spark platform is proposed to implement the framework in a cluster system. We prove that Para-Join and Pada-Join cannot only avoid reduplicate computation but also ensure the completeness of the result. Experimental results show that Para-Join can achieve high efficiency and significantly outperform than state-of-the-art approaches, meanwhile, Pada-Join can work on large datasets.

  15. A contrivance for a dynamic porous framework: cooperative guest adsorption based on square grids connected by amide-amide hydrogen bonds.

    PubMed

    Uemura, Kazuhiro; Kitagawa, Susumu; Fukui, Kôichi; Saito, Kazuya

    2004-03-31

    Flexible porous coordination polymers containing amide groups as a function origin have been synthesized and categorized as "Coordination Polymer with Amide Groups". Bispyridyl ligands with a spacer of amide group afford two-dimensional (2-D) motifs with a deformed square grid, resulting in three-dimensional (3-D) frameworks of [Co(NO(3))(2)(3-pna)(2)](n)(1), [Co(Br)(2)(3-pna)(2)](n)(2), and [[Co(NCS)(2)(4-peia)(2)].4Me(2)CO](n)(3 subset 4Me(2)CO) (3-pna = N-3-pyridylnicotinamide, 4-peia = N-(2-pyridin-4-yl-ethyl)-isonicotinamide), where the 2-D motifs are bound by complementary hydrogen bond between the amide groups. In the case of the 3 subset 4Me(2)CO, the amide groups form a contrivance for a dynamic porous framework because of their relevant position and orientation in the mutual nearest neighboring motifs. Consequently, 3 subset 4Me(2)CO shows amorphous (nonporous)-to-crystal (porous) structural rearrangement in the Me(2)CO adsorption and desorption process, where the framework of the 2-D motif is maintained. The adsorption isotherm has threshold pressure (P(th)), a sort of gate pressure. The heat of Me(2)CO adsorption (DeltaH(ad) = -25 kJ/mol) is obtained from the temperature dependence of threshold pressure (P(th)), which is close to acetone vaporization enthalpy (DeltaH(vap) = 30.99 kJ/mol).

  16. Copper-Catalyzed Intermolecular Amidation and Imidation of Unactivated Alkanes

    PubMed Central

    2015-01-01

    We report a set of rare copper-catalyzed reactions of alkanes with simple amides, sulfonamides, and imides (i.e., benzamides, tosylamides, carbamates, and phthalimide) to form the corresponding N-alkyl products. The reactions lead to functionalization at secondary C–H bonds over tertiary C–H bonds and even occur at primary C–H bonds. [(phen)Cu(phth)] (1-phth) and [(phen)Cu(phth)2] (1-phth2), which are potential intermediates in the reaction, have been isolated and fully characterized. The stoichiometric reactions of 1-phth and 1-phth2 with alkanes, alkyl radicals, and radical probes were investigated to elucidate the mechanism of the amidation. The catalytic and stoichiometric reactions require both copper and tBuOOtBu for the generation of N-alkyl product. Neither 1-phth nor 1-phth2 reacted with excess cyclohexane at 100 °C without tBuOOtBu. However, the reactions of 1-phth and 1-phth2 with tBuOOtBu afforded N-cyclohexylphthalimide (Cy-phth), N-methylphthalimide, and tert-butoxycyclohexane (Cy-OtBu) in approximate ratios of 70:20:30, respectively. Reactions with radical traps support the intermediacy of a tert-butoxy radical, which forms an alkyl radical intermediate. The intermediacy of an alkyl radical was evidenced by the catalytic reaction of cyclohexane with benzamide in the presence of CBr4, which formed exclusively bromocyclohexane. Furthermore, stoichiometric reactions of [(phen)Cu(phth)2] with tBuOOtBu and (Ph(Me)2CO)2 at 100 °C without cyclohexane afforded N-methylphthalimide (Me-phth) from β-Me scission of the alkoxy radicals to form a methyl radical. Separate reactions of cyclohexane and d12-cyclohexane with benzamide showed that the turnover-limiting step in the catalytic reaction is the C–H cleavage of cyclohexane by a tert-butoxy radical. These mechanistic data imply that the tert-butoxy radical reacts with the C–H bonds of alkanes, and the subsequent alkyl radical combines with 1-phth2 to form the corresponding N-alkyl imide product

  17. Transforming a Stable Amide into a Highly Reactive One: Capturing the Essence of Enzymatic Catalysis.

    PubMed

    Souza, Bruno S; Mora, Jose R; Wanderlind, Eduardo H; Clementin, Rosilene M; Gesser, Jose C; Fiedler, Haidi D; Nome, Faruk; Menger, Fredric M

    2017-04-05

    Aspartic proteinases, which include HIV-1 proteinase, function with two aspartate carboxy groups at the active site. This relationship has been modeled in a system possessing an otherwise unactivated amide positioned between two carboxy groups. The model amide is cleaved at an enzyme-like rate that renders the amide nonisolable at 35 °C and pH 4 owing to the joint presence of carboxy and carboxylate groups. A currently advanced theory attributing almost the entire catalytic power of enzymes to electrostatic reorganization is shown to be superfluous when suitable interatomic interactions are present. Our kinetic results are consistent with spatiotemporal concepts where embedding the amide group between two carboxylic moieties in proper geometries, at distances less than the diameter of water, leads to enzyme-like rate enhancements. Space and time are the essence of enzyme catalysis.

  18. Binary and ternary cocrystals of sulfa drug acetazolamide with pyridine carboxamides and cyclic amides.

    PubMed

    Bolla, Geetha; Nangia, Ashwini

    2016-03-01

    A novel design strategy for cocrystals of a sulfonamide drug with pyridine carboxamides and cyclic amides is developed based on synthon identification as well as size and shape match of coformers. Binary adducts of acetazolamide (ACZ) with lactams (valerolactam and caprolactam, VLM, CPR), cyclic amides (2-pyridone, labeled as 2HP and its derivatives MeHP, OMeHP) and pyridine amides (nicotinamide and picolinamide, NAM, PAM) were obtained by manual grinding, and their single crystals by solution crystallization. The heterosynthons in the binary cocrystals of ACZ with these coformers suggested a ternary combination for ACZ with pyridone and nicotinamide. Novel supramolecular synthons of ACZ with lactams and pyridine carboxamides are reported together with binary and ternary cocrystals for a sulfonamide drug. This crystal engineering study resulted in the first ternary cocrystal of acetazolamide with amide coformers, ACZ-NAM-2HP (1:1:1).

  19. Binary and ternary cocrystals of sulfa drug acetazolamide with pyridine carboxamides and cyclic amides

    PubMed Central

    Bolla, Geetha; Nangia, Ashwini

    2016-01-01

    A novel design strategy for cocrystals of a sulfonamide drug with pyridine carboxamides and cyclic amides is developed based on synthon identification as well as size and shape match of coformers. Binary adducts of acetazolamide (ACZ) with lactams (valerolactam and caprolactam, VLM, CPR), cyclic amides (2-pyridone, labeled as 2HP and its derivatives MeHP, OMeHP) and pyridine amides (nicotinamide and picolinamide, NAM, PAM) were obtained by manual grinding, and their single crystals by solution crystallization. The heterosynthons in the binary cocrystals of ACZ with these coformers suggested a ternary combination for ACZ with pyridone and nicotinamide. Novel supramolecular synthons of ACZ with lactams and pyridine carboxamides are reported together with binary and ternary cocrystals for a sulfonamide drug. This crystal engineering study resulted in the first ternary cocrystal of acetazolamide with amide coformers, ACZ–NAM–2HP (1:1:1). PMID:27006778

  20. H-localized mode in chains of hydrogen-bonded amide groups

    NASA Astrophysics Data System (ADS)

    Barthes, Mariette; Kellouai, Hassan; Page, Gabriel; Moret, Jacques; Johnson, Susanna W.; Eckert, Juergen

    1993-09-01

    New infrared measurements of the anomalous amide modes in acetanilide and its derivatives are presented. Preliminary results of structural data obtained by neutron diffraction at low temperature are also described. Besides the well-known anomalous amide-1 mode (1650 cm -1), it is shown that the NH out-of-plane bend (770 cm -1) and the “H-bond strain” (at about 105 cm -1) exhibit an anomalous increase of intensity proportional to the law exp(- T2/ Θ2), suggesting that the amide proton bears a significant electronic distribution as formerly observed for H - localized modes. Structural data, moreover, show that the thermal ellips of the amide proton has an increasing anisotropy at 15 K. Considering these new results, the theoretical model of a self-trapped “polaronic” state seems to be the most consistent with the whole set of observed anomalies in this family of crystals.

  1. First Novozym 435 lipase-catalyzed Morita-Baylis-Hillman reaction in the presence of amides.

    PubMed

    Tian, Xuemei; Zhang, Suoqin; Zheng, Liangyu

    2016-03-01

    The first Novozym 435 lipase-catalyzed Morita-Baylis-Hillman (MBH) reaction with amides as co-catalyst was realized. Results showed that neither Novozym 435 nor amide can independently catalyze the reaction. This co-catalytic system that used a catalytic amount of Novozym 435 with a corresponding amount of amide was established and optimized. The MBH reaction strongly depended on the structure of aldehyde substrate, amide co-catalyst, and reaction additives. The optimized reaction yield (43.4%) was achieved in the Novozym 435-catalyzed MBH reaction of 2, 4-dinitrobenzaldehyde and cyclohexenone with isonicotinamide as co-catalyst and β-cyclodextrin as additive only in 2 days. Although enantioselectivity of Novozym 435 was not found, the results were still significant because an MBH reaction using lipase as biocatalyst was realized for the first time.

  2. Pd-Catalyzed N-Arylation of Secondary Acyclic Amides: Catalyst Development, Scope, and Computational Study

    PubMed Central

    Hicks, Jacqueline D.; Hyde, Alan M.; Cuezva, Alberto Martinez; Buchwald, Stephen L.

    2009-01-01

    We report the efficient N-arylation of acyclic secondary amides and related nucleophiles with aryl nonaflates, triflates, and chlorides. This method allows for easy variation of the aromatic component in tertiary aryl amides. A new biaryl phosphine with P-bound 3,5-(bis)trifluoromethylphenyl groups was found to be uniquely effective for this amidation. The critical aspects of the ligand were explored through synthetic, mechanistic, and computational studies. Systematic variation of the ligand revealed the importance of (1) a methoxy group on the aromatic carbon of the “top ring” ortho to the phosphorus and (2) two highly electron-withdrawing P-bound 3,5-(bis)trifluoromethylphenyl groups. Computational studies suggest the electron-deficient nature of the ligand is important in facilitating amide binding to the LPd(II)(Ph)(X) intermediate. PMID:19886610

  3. Sodium methoxide: a simple but highly efficient catalyst for the direct amidation of esters.

    PubMed

    Ohshima, Takashi; Hayashi, Yukiko; Agura, Kazushi; Fujii, Yuka; Yoshiyama, Asako; Mashima, Kazushi

    2012-06-04

    A simple NaOMe catalyst provides superior accessibility to a wide variety of functionalized amides including peptides through direct amination of esters in an atom-economical and environmentally benign way.

  4. Crystal structure of the high-energy-density material guanylurea dipicryl-amide.

    PubMed

    Deblitz, Raik; Hrib, Cristian G; Hilfert, Liane; Edelmann, Frank T

    2014-08-01

    The title compound, 1-carbamoylguanidinium bis-(2,4,6-tri-nitro-phen-yl)amide [H2NC(=O)NHC(NH2)2](+)[N{C6H2(NO2)3-2,4,6}2](-) (= guanylurea dipicryl-amide), was prepared as dark-red block-like crystals in 70% yield by salt-metathesis reaction between guanylurea sulfate and sodium dipicryl-amide. In the solid state, the new compound builds up an array of mutually linked guanylurea cations and dipicryl-amide anions. The crystal packing is dominated by an extensive network of N-H⋯O hydrogen bonds, resulting in a high density of 1.795 Mg m(-3), which makes the title compound a potential secondary explosive.

  5. Ceramic-metal composite article and joining method

    DOEpatents

    Kang, S.; Selverian, J.H.; Kim, H.J.; Dunn, E.M.; Kim, K.S.

    1992-04-28

    A ceramic-metal article including a ceramic rod, a metal rod, and a braze joining the ceramic and metal rods at a braze area of a coaxial bore in the metal rod is described. The bore gradually decreases in diameter, having an inward seat area sized for close sliding fit about the ceramic, a larger brazing area near the joint end, and a void area intermediate the braze and seat areas. The ceramic is seated without brazing in the bore seat area. The side wall between the brazing area and the metal outer surface is about 0.030-0.080 inch. The braze includes an inner braze layer, an outer braze layer, and an interlayer about 0.030-0.090 inch thick. A shoulder between the brazing and void areas supports the interlayer during bonding while preventing bonding between the void area and the ceramic member, leaving a void space between the void area and the ceramic member. A venting orifice extends generally radially through the metal member from the outer surface to the void space. The braze layers are palladium, platinum, gold, silver, copper, nickel, indium, chromium, molybdenum, niobium, iron, aluminum, or alloys thereof. Preferred is a gold-palladium-nickel brazing alloy. The interlayer is nickel, molybdenum, copper, tantalum, tungsten, niobium, aluminum, cobalt, iron, or an alloy thereof. 4 figs.

  6. Ceramic-metal composite article and joining method

    DOEpatents

    Kang, Shinhoo; Selverian, John H.; Kim, Hans J.; Dunn, Edmund M.; Kim, Kyung S.

    1992-01-01

    A ceramic-metal article including a ceramic rod, a metal rod, and a braze joining the ceramic and metal rods at a braze area of a coaxial bore in the metal rod. The bore gradually decreases in diameter, having an inward seat area sized for close sliding fit about the ceramic, a larger brazing area near the joint end, and a void area intermediate the braze and seat areas. The ceramic is seated without brazing in the bore seat area. The side wall between the brazing area and the metal outer surface is about 0.030-0.080 inch. The braze includes an inner braze layer, an outer braze layer, and an interlayer about 0.030-0.090 inch thick. A shoulder between the brazing and void areas supports the interlayer during bonding while preventing bonding between the void area and the ceramic member, leaving a void space between the void area and the ceramic member. A venting orifice extends generally radially through the metal member from the outer surface to the void space. The braze layers are palladium, platinum, gold, silver, copper, nickel, indium, chromium, molybdenum, niobium, iron, aluminum, or alloys thereof. Preferred is a gold-palladium-nickel brazing alloy. The interlayer is nickel, molybdenum, copper, tantalum, tungsten, niobium, aluminum, cobalt, iron, or an alloy thereof.

  7. Indian oil company joins efforts to reduce methane emissions

    NASA Astrophysics Data System (ADS)

    Kumar, Mohi

    The Oil and Natural Gas Corp, Ltd. (ONGC), headquartered in Dehradun, India, has joined seven U.S. and Canadian oil and natural gas companies as a partner in a U.S. Environmental Protection Agency program to reduce greenhouse gas emissions. EPA's Natural Gas STAR International Program aims to reduce methane emissions from the oil and natural gas sector while delivering more gas to markets around the world. With this partnership, ONGC agrees to implement emissions reduction practices and to submit annual reports on progress achieved; EPA agrees to assist ONGC with training technicians in new cost-effective technologies that will help achieve target emissions. The Natural Gas STAR International Program is administered under the Methane to Markets Partnership, a group of 20 countries and 600 companies across the globe that since 2004 has volunteered to cut methane emissions. More information on EPA's agreement with ONGC can be found at http://www.epa.gov/gasstar/index.htm; information about the Methane to Markets Partnership can be found at http://www.methanetomarkets.org.

  8. Structure-Property Correlations in Microwave Joining of Inconel 718

    NASA Astrophysics Data System (ADS)

    Bansal, Amit; Sharma, Apurbba Kumar; Kumar, Pradeep; Das, Shantanu

    2015-09-01

    The butt joining of Inconel 718 plates at 981°C solution treated and aged (981STA) condition was carried out using the microwave hybrid heating technique with Inconel 718 powder as a filler material. The developed joints were free from any microfissures (cracks) and were metallurgically bonded through complete melting of the powder particles. The as-welded joints were subjected to postweld heat treatments, including direct-aged, 981STA and 1080STA. The microstructural features of the welded joints were investigated using a field emission-scanning electron microscope equipped with x-ray elemental analysis. Microhardness and room-temperature tensile properties of the welded joints were evaluated. The postweld heat-treated specimens exhibited higher microhardness and tensile strength than the as-welded specimens due to the formation of strengthening precipitates in the microstructure after postweld heat treatments. The microhardness of the fusion zone of the joint in 1080STA condition was higher than all welded conditions due to the complete dissolution of Laves phase after 1080STA treatment. However, the tensile strength of the welded specimen in 981STA condition was higher than all welded conditions. The tensile strength in 1080STA condition was lower than that in 981STA condition because of the grain coarsening that took place after 1080STA condition. The fractography of the fractured surfaces was carried out to determine the structure-property-fracture correlation.

  9. Moments of genome evolution by Double Cut-and-Join.

    PubMed

    Biller, Priscila; Guéguen, Laurent; Tannier, Eric

    2015-01-01

    We study statistical estimators of the number of genomic events separating two genomes under a Double Cut-and Join (DCJ) rearrangement model, by a method of moment estimation. We first propose an exact, closed, analytically invertible formula for the expected number of breakpoints after a given number of DCJs. This improves over the heuristic, recursive and computationally slower previously proposed one. Then we explore the analogies of genome evolution by DCJ with evolution of binary sequences under substitutions, permutations under transpositions, and random graphs. Each of these are presented in the literature with intuitive justifications, and are used to import results from better known fields. We formalize the relations by proving a correspondence between moments in sequence and genome evolution, provided substitutions appear four by four in the corresponding model. Eventually we prove a bounded error on two estimators of the number of cycles in the breakpoint graph after a given number of rearrangements, by an analogy with cycles in permutations and components in random graphs.

  10. Predictive modeling of reactive wetting and metal joining.

    SciTech Connect

    van Swol, Frank B.

    2013-09-01

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

  11. Thermal-stress-free fasteners for joining orthotropic materials

    NASA Technical Reports Server (NTRS)

    Blosser, M. L.

    1987-01-01

    Hot structures fabricated from orthotropic materials are an attractive design option for future high speed vehicles. Joining subassemblies of these materials with standard cylindrical fasteners can lead to loose joints or highly stressed joints due to thermal stress. A method has been developed to eliminate thermal stresses and maintain a tight joint by shaping the fastener and mating hole. This method allows both materials (fastener and structure), with different coefficients of thermal expansion (CTEs) in each of the three material directions, to expand freely with temperature yet remain in contact. For the assumptions made in the analysis, the joint will remain snug, yet free of thermal stress at any temperature. Finite element analysis was used to verify several thermal-stress-free fasteners and to show that conical fasteners, which are thermal-stress-free for isotropic materials, can reduce thermal stresses for transversely isotropic materials compared to a cylindrical fastener. Equations for thermal-stress-free shapes are presented and typical fastener shapes are shown.

  12. Joining of Dissimilar Metals By Friction Stir Welding

    NASA Astrophysics Data System (ADS)

    Firouzdor, Vahid

    The use of friction stir welding (FSW) as a new process for joining dissimilar metals has been studied frequently recently. The present study investigated dissimilar-metal FSW between Al and Mg alloys using the widely used alloys 6061 Al and AZ31B Mg. It focused on the issue of how the joint strength is affected by the welding conditions, including the positions of Al and Mg with respect to the welding tool, the tool travel speed and the tool rotation speed. In spite of studies conducted by many other investigators, understanding of this fundamental issue is still rather limited. Unlike those studies, the present study: (1) determined the heat input by torque and temperature measurements during welding and used it to explain the effect of the welding conditions on the joint strength, (2) used color metallography with Al, Mg, Al3Mg2 and Al12Mg17 shown in different colors to clearly revealed the effect of the welding conditions on the formation of intermetallic compounds and material flow, which are affected by the heat input and which in turn affect the joint strength, and (3) determined the windows for selecting the travel and rotation speeds to optimize the joint strength for various material positions. Furthermore, conventional lap FSW was modified and the joint strength and ductility of the resultant welds were both increased significantly. The modified lap FSW was applied subsequently to Al-to-Cu FSW. The intermetallic compounds in Al-Mg and Al-Cu welds were identified.

  13. Join the "Club of the Sterilized" Hanoi urges.

    PubMed

    1996-01-01

    In Viet Nam, the government has mounted a program of encouraging sterilization to control population growth. Peasants who have been sterilized are being urged to form and join special motivational clubs to give momentum to the initiative, and financial incentives are provided to those who accept sterilization after having two children. The government action follows concerns that rapid population growth will strain the country's newly achieved economic gains and ability to produce enough food. Until recently, large families were eligible for greater amounts of land being allocated, and the government's new initiative faces challenges in districts that are prosperous or are predominantly Roman Catholic. With domestic funds in short supply, Viet Nam has depended upon the UN Population Fund for training, equipment supply, and development of an assembly line at a condom factory. The government plans to screen pregnant women for fetal anomalies to insure that only healthy fetuses are carried to term. For several decades, Viet Nam will be suffering from the effects of the spraying of herbicides undertaken by the US during the war. Miscarriages, stillbirths, and fetal deformities are among those effects.

  14. Asian international students' barriers to joining group counseling.

    PubMed

    Lee, Ji-Yeon

    2014-10-01

    This cross-sectional study examined anticipated reactions to group participation among Asian international students (ISs). Structural equation modeling confirmed that Asian ISs' (n = 180) level of acculturation was associated with their attitude toward joining group counseling, which is partially mediated by their stigma toward help-seeking. The results of multiple regression analyses indicated that ISs who reported higher place dependence, stigma toward help-seeking, and fear of negative evaluation reported more fear about disclosing emotional parts of themselves to other group members in the presence of a group member from the same country of origin. The results showed that ISs' perceived difficulties in providing feedback to a group member in the presence of an IS from the same country of origin were predicted by low place identity, high place dependence, and more stigma. International students' willingness to disclose and provide feedback in a group counseling setting was compared in three different hypothetical situations based on other group members' demographics, and the results showed that ISs are more afraid of self-disclosure in the presence of an international student from the same country.

  15. Laser Assisted Joining of Hybrid Polyamide-aluminum Structures

    NASA Astrophysics Data System (ADS)

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

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

  16. Controlled joining of Ag nanoparticles with femtosecond laser radiation

    NASA Astrophysics Data System (ADS)

    Huang, H.; Liu, L.; Peng, P.; Hu, A.; Duley, W. W.; Zhou, Y.

    2012-12-01

    We show that it is possible to tailor the gap separation and interface geometry between adjacent Ag nanoparticles (NPs) by controlling fluence when irradiating with pulses from a fs laser. Unirradiated samples extracted from aqueous solution consist of networks of Ag NPs coated with polyvinylpyrrolidone (PVP). At low laser fluence, bonding between NPs occurs via the formation of an intervening hydrogenated amorphous carbon (α-C:H) layer resulting from the laser-induced decomposition of PVP. This occurs when electrons are emitted at hot-spots created by the trapping of plasmons. The thickness of the α-C:H layer determines the minimum separation between NPs. Ag NPs with different contact geometries can be produced by irradiation of the networks in solution at fluences exceeding the threshold for the formation of α-C:H. At fluences between 200 and 380 μJ/cm2, the α-C:H interface layer is replaced with a metallic neck. Surface enhanced Raman scattering (SERS) has been used to quantify the electromagnetic field enhancement in joined NP samples. We find that Ag NPs bonded by α-C:H and exhibiting a narrow gap possess the highest SERS enhancement.

  17. Preparation and phytotoxicity of novel kaurane diterpene amides with potential use as herbicides.

    PubMed

    Boaventura, Maria Amélia Diamantino; Pereira, Rondinelle Gomes; de Oliveira Freitas, Luiza B; Dos Reis, Leandro Alves; da Silva Vieira, Henriete

    2008-05-14

    Novel kaurane ditepene monoamides were synthesized in good yields directly from kaurenoic ( 1) and grandiflorenic ( 2) acids and unprotected symmetrical diamines, using a modified protocol for monoacylation. Amides from 1 and 2 and monoamines were also obtained and tested against seed germination and growth of radicle and shoot of Lactuca sativa (lettuce), at 10 (-3), 10 (-5), and 10 (-7) M. Amides from symmetrical diamines showed significant inhibitory activity at higher concentrations.

  18. Actinide-lanthanide separation with solvents on the base of amides of heterocyclic diacids

    SciTech Connect

    Babain, V.A.; Alyapyshev, M.Y.; Tkachenko, L.I.

    2013-07-01

    The separation of actinides from lanthanides with a particular emphasis on Am(III) from Eu(III) with amides of heterocyclic dicarboxylic diacids was reviewed. It was shown that the di-amides of the 2,2'-dipyridyl-6,6'-dicarboxylic acid are the most promising ligands for the simultaneous selective recovery of actinides from HLLW (high level radioactive liquid waste) within the GANEX concept. (author)

  19. Multicomponent Approach to the Synthesis of Oxidized Amides through Nitrile Hydrozirconation

    PubMed Central

    Wan, Shuangyi; Green, Michael E.; Park, Jung-Hyun; Floreancig, Paul E.

    2008-01-01

    “Oxidized” amides, as represented by acyl aminals and acyl hemiaminals, are integral subunits of several natural products that exhibit useful biological activity. In this manuscript a multicomponent approach to these groups from acylimine intermediates is demonstrated. The acylimines are accessed through a sequence of nitrile hydrozirconation and acylation, making this highly versatile amide synthesis useful for a range of range of applications in target- and diversity-oriented synthesis. PMID:18020344

  20. Effects of three related amides on microecosystem stability

    SciTech Connect

    Flum, T.F.; Shannon, L.J.

    1987-04-01

    Three related amides (diuron, 2-(octyloxy) acetanilide, and salicylanilide) were evaluated for toxicity to aquatic microcosm communities. Effects were measured at the ecosystem level using changes in pH, Eh (redox potential), and dissolved oxygen as indicators of toxicity. These values were used to calculate the resistance, resilience, and relative instability of the microecosystems to each compound at comparable dose levels of approximately 2500 micrograms/liter. Such measures have often been used in a theoretical context, but have not received wide practical application. The systems showed low resistance and no resilience to diuron, high resistance and low resilience to 2-(octyloxy) acetanilide, and no response to salicylanilide. At a higher exposure level (9800 micrograms/liter salicylanilide), the systems showed low resistance and high resilience. Both this approach and more traditional dose-response measures of toxicity indicated that diuron was clearly the most toxic compound, followed by 2-(octyloxy) acetanilide and salicylanilide. While microcosm toxicity tests were slightly less sensitive than some single species tests, they provided important additional information on the extent of perturbations and the rate of ecosystem recovery.

  1. Mapping human brain fatty acid amide hydrolase activity with PET

    PubMed Central

    Rusjan, Pablo M; Wilson, Alan A; Mizrahi, Romina; Boileau, Isabelle; Chavez, Sofia E; Lobaugh, Nancy J; Kish, Stephen J; Houle, Sylvain; Tong, Junchao

    2013-01-01

    Endocannabinoid tone has recently been implicated in a number of prevalent neuropsychiatric conditions. [11C]CURB is the first available positron emission tomography (PET) radiotracer for imaging fatty acid amide hydrolase (FAAH), the enzyme which metabolizes the prominent endocannabinoid anandamide. Here, we sought to determine the most suitable kinetic modeling approach for quantifying [11C]CURB that binds selectively to FAAH. Six healthy volunteers were scanned with arterial blood sampling for 90 minutes. Kinetic parameters were estimated regionally using a one-tissue compartment model (TCM), a 2-TCM with and without irreversible trapping, and an irreversible 3-TCM. The 2-TCM with irreversible trapping provided the best identifiability of PET outcome measures among the approaches studied (coefficient of variation (COV) of the net influx constant Ki and the composite parameter λk3 (λ=K1/k2) <5%, and COV(k3)<10%). Reducing scan time to 60 minutes did not compromise the identifiability of rate constants. Arterial spin labeling measures of regional cerebral blood flow were only slightly correlated with Ki, but not with k3 or λk3. Our data suggest that λk3 is sensitive to changes in FAAH activity, therefore, optimal for PET quantification of FAAH activities with [11C]CURB. Simulations showed that [11C]CURB binding in healthy subjects is far from a flow-limited uptake. PMID:23211960

  2. Synthesis and characterization of ester and amide derivatives of titanium(IV) carboxymethylphosphonate

    SciTech Connect

    Melánová, Klára; Beneš, Ludvík; Trchová, Miroslava; Svoboda, Jan; Zima, Vítězslav

    2013-06-15

    A set of layered ester and amide derivatives of titanium(IV) carboxymethylphosphonate was prepared by solvothermal treatment of amorphous titanium(IV) carboxymethylphosphonate with corresponding 1-alkanols, 1,ω-alkanediols, 1-aminoalkanes, 1,ω-diaminoalkanes and 1,ω-amino alcohols and characterized by powder X-ray diffraction, IR spectroscopy and thermogravimetric analysis. Whereas alkyl chains with one functional group form bilayers tilted to the layers, 1,ω-diaminoalkanes and most of 1,ω-alkanediols form bridges connecting the adjacent layers. In the case of amino alcohols, the alkyl chains form bilayer and either hydroxyl or amino group is used for bonding. This simple method for the synthesis of ester and amide derivatives does not require preparation of acid chloride derivative as a precursor or pre-intercalation with alkylamines and can be used also for the preparation of ester and amide derivatives of titanium carboxyethylphosphonate and zirconium carboxymethylphosphonate. - Graphical abstract: Ester and amide derivatives of layered titanium carboxymethylphosphonate were prepared by solvothermal treatment of amorphous solid with alkanol or alkylamine. - Highlights: • Ester and amide derivatives of titanium carboxymethylphosphonate. • Solvothermal treatment of amorphous solid with alkanol or alkylamine. • Ester and amide formation confirmed by IR spectroscopy.

  3. Effect of amide bonds on the self-assembly of gemini surfactants.

    PubMed

    Hoque, Jiaul; Gonuguntla, Spandhana; Yarlagadda, Venkateswarlu; Aswal, Vinod K; Haldar, Jayanta

    2014-06-21

    This study provides an insight into the micellar aggregation properties in aqueous solutions of various gemini surfactants bearing one or more amide groups at the side chains and/or in the spacer by conductivity and small angle neutron scattering (SANS) studies. The amide functionality was found to enhance the surfactant aggregation properties as compared to the surfactants having no amide bond. Furthermore, the aggregation properties of the gemini surfactants bearing amide groups were found to strongly depend on the position and number of amide bonds. With the increase in the number of amide bonds, the aggregation number (N) and the size of the micelles increased. Additionally, the size and shape of the micelles were also found to depend both on the hydrocarbon chain length and the spacer chain length. It was also found that the aggregation number and the size of the micelles increased with an increase in concentration and decreased with an increase in temperature. The critical micellar concentration (CMC) values of the gemini surfactants obtained by a conductometric method were found to vary greatly with variation in the hydrocarbon chain.

  4. Computational study of the effects of steric hindrance on amide bond cleavage.

    PubMed

    Matsubara, Toshiaki; Ueta, Chikako

    2014-09-25

    The reaction mechanism of amide bond cleavages of the 2,2,6,6-tetramethylpiperidine derivatives, which proceeds in methanol solvent under mild conditions, is examined by the density functional method (B3LYP) using a model substrate. We performed the calculations to clarify the reason why the amide bond is readily broken in the present system, on the basis of an experimentally proposed "proton switching pathway" that is different from the generally known mechanisms. As a result, it was found that the stepwise decomposition of the amide bond by the "proton switching pathway" significantly lowers the energy barrier. The delocalization of the π electron in the -C(═O)-N< part is hindered by the steric effect of the four Me groups of the piperidine so that the acetyl group can easily rotate around the C-N axis and then the α-H migrates to the amide N. The subsequent amide bond dissociation, which is thought to be a rate-determining step in the experiment, was very facile. The reaction is completed by the addition of methanol to the formed ketene. Both the energy barriers of the α-H migration to the amide N and the methanol addition to ketene are largely decreased by the mediation of methanol solvent molecules. The rate-determining step of the entire reaction was found to be the α-H migration.

  5. Computational Amide I Spectroscopy for Refinement of Disordered Peptide Ensembles: Maximum Entropy and Related Approaches

    NASA Astrophysics Data System (ADS)

    Reppert, Michael; Tokmakoff, Andrei

    The structural characterization of intrinsically disordered peptides (IDPs) presents a challenging biophysical problem. Extreme heterogeneity and rapid conformational interconversion make traditional methods difficult to interpret. Due to its ultrafast (ps) shutter speed, Amide I vibrational spectroscopy has received considerable interest as a novel technique to probe IDP structure and dynamics. Historically, Amide I spectroscopy has been limited to delivering global secondary structural information. More recently, however, the method has been adapted to study structure at the local level through incorporation of isotope labels into the protein backbone at specific amide bonds. Thanks to the acute sensitivity of Amide I frequencies to local electrostatic interactions-particularly hydrogen bonds-spectroscopic data on isotope labeled residues directly reports on local peptide conformation. Quantitative information can be extracted using electrostatic frequency maps which translate molecular dynamics trajectories into Amide I spectra for comparison with experiment. Here we present our recent efforts in the development of a rigorous approach to incorporating Amide I spectroscopic restraints into refined molecular dynamics structural ensembles using maximum entropy and related approaches. By combining force field predictions with experimental spectroscopic data, we construct refined structural ensembles for a family of short, strongly disordered, elastin-like peptides in aqueous solution.

  6. UV resonance Raman investigation of the aqueous solvation dependence of primary amide vibrations.

    PubMed

    Punihaole, David; Jakubek, Ryan S; Dahlburg, Elizabeth M; Hong, Zhenmin; Myshakina, Nataliya S; Geib, Steven; Asher, Sanford A

    2015-03-12

    We investigated the normal mode composition and the aqueous solvation dependence of the primary amide vibrations of propanamide. Infrared, normal Raman, and UV resonance Raman (UVRR) spectroscopy were applied in conjunction with density functional theory (DFT) to assign the vibrations of crystalline propanamide. We examined the aqueous solvation dependence of the primary amide UVRR bands by measuring spectra in different acetonitrile/water mixtures. As previously observed in the UVRR spectra of N-methylacetamide, all of the resonance enhanced primary amide bands, except for the Amide I (AmI), show increased UVRR cross sections as the solvent becomes water-rich. These spectral trends are rationalized by a model wherein the hydrogen bonding and the high dielectric constant of water stabilizes the ground state dipolar (-)O-C═NH2(+) resonance structure over the neutral O═C-NH2 resonance structure. Thus, vibrations with large C-N stretching show increased UVRR cross sections because the C-N displacement between the electronic ground and excited state increases along the C-N bond. In contrast, vibrations dominated by C═O stretching, such as the AmI, show a decreased displacement between the electronic ground and excited state, which result in a decreased UVRR cross section upon aqueous solvation. The UVRR primary amide vibrations can be used as sensitive spectroscopic markers to study the local dielectric constant and hydrogen bonding environments of the primary amide side chains of glutamine (Gln) and asparagine (Asn).

  7. The Effects of Joining Methods on the Resistivity of W-Cu Alloy and Cu Joint

    NASA Astrophysics Data System (ADS)

    Chen, Chunhuan; Liu, Xiaojing; Wang, Zhenbo

    In this paper, three joining methods are employed to join W-Cu alloy and Cu to investigate the effect of joining methods on the resistivity of the joint. The results show that W-Cu alloy is well bonding to the Cu substrate when joining by diffusion vacuum bonding and brazing in vacuum methods. Welding defects is apt to occur when joining by brazing in air. The lowest resistivity of the joint welded is obtained by vacuum diffusion bonding, which approximates to the W-Cu alloy while that for the joint brazed in air is the highest. Vacuum diffusion bonding method is the best choice when the demand of conductivity is vital while the mechanical reliability is not critical. Otherwise, brazing in vacuum is the prior option.

  8. Robust Joining and Assembly of Ceramic Matrix Composites for High Temperature Applications

    NASA Technical Reports Server (NTRS)

    Singh, Mrityunjay

    2003-01-01

    Advanced ceramic matrix composites (CMCs) are under active consideration for use in a wide variety of high temperature applications within the aerospace, energy, and nuclear industries. The engineering designs of CMC 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. 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. A wide variety of ceramic composites, in different shapes and sizes, have been joined using an affordable, robust ceramic joining technology (ARCJoinT). Microstructure and mechanical properties of joints in melt infiltrated and CVI Sic matrix composites will be reported. Various joint design philosophies and design issues in joining of composites will be discussed.

  9. Microwave Ignited Combustion Synthesis as a Joining Technique for Dissimilar Materials

    NASA Astrophysics Data System (ADS)

    Rosa, Roberto; Colombini, Elena; Veronesi, Paolo; Poli, Giorgio; Leonelli, Cristina

    2012-05-01

    Microwave energy has been exploited to ignite combustion synthesis (CS) reactions of properly designed powders mixtures, in order to rapidly reach the joining between different kinds of materials, including metals (Titanium and Inconel) and ceramics (SiC). Beside the great advantage offered by CS itself, i.e., rapid and highly localized heat generation, the microwaves selectivity in being absorbed by micrometric metallic powders and not by bulk metallic components represents a further intriguing aspect in advanced materials joining applications, namely the possibility to avoid the exposition to high temperatures of the entire substrates to be joined. Moreover, in case of microwaves absorbing substrates, the competitive microwaves absorption by both substrates and powdered joining material, leads to the possibility of adhesion, interdiffusion and chemical bonding enhancements. In this study, both experimental and numerical simulation results are used to highlight the great potentialities of microwave ignited CS in the joining of advanced materials.

  10. Investigating the Pulse Mode Laser Joining of Overlapped Plastic and Metal Sheets

    NASA Astrophysics Data System (ADS)

    Bauernhuber, Andor; Markovits, Tamás; Takács, János

    The growing utilization of plastic materials in our devices calls for joining them with traditional, often applied structural materials, like metals. Laser assisted metal plastic joining can be used to solve the problem mentioned above, however, relatively few materials have been investigated which could be used to create this special joint. In the course of this research, authors used pulse mode Nd:YAG laser source, structural steel and poly(methyl methacrylate) to create joining between rarely examined material pairs so far, and to explore the effects of technological settings like laser pulse shape, laser spot size, welding speed and joint strength. Material surfaces were also modified (sand blasting,) to enhance joint properties. In plastic material during joining and torn surfaces were investigated. Joints with good strength results were prepared to enable further research on transparent-absorbent metal plastic joining.

  11. Query scheduling and implementation for multiple join operations in network databases

    NASA Astrophysics Data System (ADS)

    Huang, Xin-Mao; Chen, Ming-Syan

    1998-08-01

    Recently, as the rapid advances in Internet technologies, there have been many related tools and applications developed, including improvement in browsers, enhancement in server functionality, and also standardization of network protocols. These technology developments have influenced the database architecture, which evolves from centralized ones, to distributed ones, and then to networked ones. While having its own advantages, a network database also encounters the problem of storage and retrieval for decentralized data. Specifically, how to perform a join operation efficiently is a difficult problem since the data transmission over the network is expensive and how to minimize the transmission cost for performing a join is intrinsically hard to solve. Such a problem is even more important and difficult to resolve when a multi-join is being carried out. In this paper, we shall investigate the problem of multi-join execution in a network database and develop a schedule that is able to not only effectively decompose a multi-join into a proper join and semi-join sequence but also efficiently conduct its execution. In addition,w e will utilize related technologies, including Java applets, JDBC, etc, to implement a Web-base network database. In this network database system, users can access the data and issue the multi-join query through a proper Web interface, and the system will take full advantage of the scheduler devised to perform a multi-join query so as to improve the overall system performance. Due to the increasing popularity of Internet, the use of multi-join is expected to be even more frequent, and its execution, without proper scheduling, is becoming the bottleneck of a network database. In view of this, we believe this study is very timely and the results are of both theoretical and practical importance.

  12. Can Joined-Up Data Lead to Joined-Up Thinking? The Western Australian Developmental Pathways Project

    PubMed Central

    Stanley, Fiona; Glauert, Rebecca; McKenzie, Anne; O'Donnell, Melissa

    2011-01-01

    Modern societies are challenged by “wicked problems” – by definition, those that are difficult to define, multi-causal and hard to treat. Problems such as low birth weight, obesity, mental ill health, teenage pregnancy, educational difficulties and juvenile crime fit this category. Given the complex nature of these problems, they require the best data in order to measure them, guide policy frameworks and evaluate whether the steps taken to address them are actually making a difference. What such problems really require are joined-up approaches to enable effective solutions. In this paper, we describe a unique initiative to encourage a more preventive, whole-of-government approach to these problems – the Developmental Pathways Project, which has enabled the linkage of a large number of de-identified administrative databases in order to explore the pathways into and out of the negative outcomes affecting our children and youth. This project has not only enabled the linkage of agency data, but also of agency personnel, in order to improve and promote cross-agency research, policy and preventive solutions. Through the use of these linkages we are attempting to shift the paradigm to encourage agencies to appreciate that these “wicked problems” demand a preventive approach, as well as the provision of effective services for those already affected. PMID:24933374

  13. High-School Teams Joining Massive Pulsar Search

    NASA Astrophysics Data System (ADS)

    2008-09-01

    High school students and teachers will join astronomers on the cutting edge of science under a program to be operated by the National Radio Astronomy Observatory (NRAO) and West Virginia University (WVU), and funded by the National Science Foundation (NSF). The program, called the Pulsar Search Collaboratory, will engage West Virginia students and teachers in a massive search for new pulsars using data from the Robert C. Byrd Green Bank Telescope (GBT). Sue Ann Heatherly Sue Ann Heatherly, NRAO Education Officer CREDIT: Bill Saxton, NRAO/AUI/NSF (Click on image for larger version) The NSF announced a $892,838 grant to NRAO and WVU to conduct the three-year program. The project will involve 60 teachers and some 600 students in helping astronomers analyze data from 1500 hours of observing time on the GBT. The 120 terabytes of data produced by some 70,000 individual pointings of the giant, 17-million-pound telescope is expected to reveal dozens of previously-unknown pulsars. "The students in this program will be partners in frontier research, discovering new pulsars and measuring changes in pulsars already known," said Sue Ann Heatherly, the NRAO Education Officer in Green Bank and Principal Investigator in the project. Pulsars are superdense neutron stars, the corpses of massive stars that have exploded as supernovae. As the neutron star spins, lighthouse-like beams of radio waves, streaming from the poles of its powerful magnetic field, sweep through space. When one of these beams sweeps across the Earth, radio telescopes can capture the pulse of radio waves. Pulsars serve as exotic laboratories for studying the physics of extreme conditions. Scientists can learn valuable new information about the physics of subatomic particles, electromagnetics, and General Relativity by observing pulsars and the changes they undergo over time. The Pulsar Search Collaboratory (PSC) combines the capabilities of NRAO and WVU to provide a unique opportunity for teachers and students

  14. Join the NASA Science Mission Directorate Scientist Speaker's Bureau!

    NASA Astrophysics Data System (ADS)

    Dalton, H.; Shupla, C. B.; Buxner, S.; Shipp, S. S.

    2013-12-01

    Join the new NASA SMD Scientist Speaker's Bureau, an online portal to connect scientists interested in getting involved in E/PO projects (e.g., giving public talks, classroom visits, and virtual connections) with audiences! The Scientist Speaker's Bureau helps educators and institutions connect with NASA scientists who are interested in giving presentations, based upon the topic, logistics, and audience. Aside from name, organization, location, bio, and (optional) photo and website, the information that scientists enter into this database will not be made public; instead, it will be used to help match scientists with the requests being placed. One of the most common ways for scientists to interact with students, adults, and general public audiences is to give presentations about or related to their science. However, most educators do not have a simple way to connect with those planetary scientists, Earth scientists, heliophysicists, and astronomers who are interested and available to speak with their audiences. This system is designed to help meet the need for connecting potential audiences to interested scientists. The information input into the database (availability to travel, willingness to present online or in person, interest in presenting to different age groups and sizes of audience, topics, and more) will be used to help match scientists (you!) with the requests being placed by educators. All NASA-funded Earth and space scientists engaged in active research are invited to fill out the short registration form, including those who are involved in missions, institutes, grants, and those who are using NASA science data in their research, and more. There is particular need for young scientists, such as graduate students and post-doctoral researchers, and women and people of diverse backgrounds. Submit your information at http://www.lpi.usra.edu/education/speaker.

  15. Austria to join ESO on 1 July 2008

    NASA Astrophysics Data System (ADS)

    2008-06-01

    Today, at a ceremony in Vienna, the Austrian Minister for Science and Research, Johannes Hahn and the ESO Director General, Tim de Zeeuw, signed the formal Accession Agreement between Austria and ESO, paving the way for Austria to join ESO as its 14th member state by 1 July this year. Signing Austria Agreement ESO PR Photo 20a/08 The Signing Ceremony "This will not only give the high-quality Austrian astronomical community full access to ESO's facilities, it will give Austrian scientists a say, together with their colleagues from the other member-states, in shaping the future of our science," said Tim de Zeeuw. The signing of the Agreement followed the unanimous approval by the ESO Council during its meeting in Prague on 3 June and the decision by the Austrian Government on 25 June. At the ceremony, Minister Hahn emphasised that the accession of Austria to ESO is a strong commitment to fundamental research and particularly to astronomy. "This sustainable investment enables Austrian science to gain access to a leading, international research infrastructure, and provides an important impulse for the attractiveness of Austria as a place for research," he said. "With the signature of the agreement today we bring a long discussion to a happy end and Austrian astronomy to new horizons." Since the Agreement means accession to an international convention, the agreement must now be submitted to the Austrian Parliament for ratification. "It is not possible to plan for radical changes, but ideal conditions will be created by this accession, which will strengthen Austrian and European astronomy. It is now for the scientists to use this opportunity," concluded the Austrian Minister.

  16. Nonhomologous end joining-mediated gene replacement in plant cells.

    PubMed

    Weinthal, Dan Michael; Taylor, Roslyn Ann; Tzfira, Tzvi

    2013-05-01

    Stimulation of the homologous recombination DNA-repair pathway via the induction of genomic double-strand breaks (DSBs) by zinc finger nucleases (ZFNs) has been deployed for gene replacement in plant cells. Nonhomologous end joining (NHEJ)-mediated repair of DSBs, on the other hand, has been utilized for the induction of site-specific mutagenesis in plants. Since NHEJ is the dominant DSB repair pathway and can also lead to the capture of foreign DNA molecules, we suggest that it can also be deployed for gene replacement. An acceptor DNA molecule in which a green fluorescent protein (GFP) coding sequence (gfp) was flanked by ZFN recognition sequences was used to produce transgenic target plants. A donor DNA molecule in which a promoterless hygromycin B phosphotransferase-encoding gene (hpt) was flanked by ZFN recognition sequences was constructed. The donor DNA molecule and ZFN expression cassette were delivered into target plants. ZFN-mediated site-specific mutagenesis and complete removal of the GFP coding sequence resulted in the recovery of hygromycin-resistant plants that no longer expressed GFP and in which the hpt gene was unlinked to the acceptor DNA. More importantly, ZFN-mediated digestion of both donor and acceptor DNA molecules resulted in NHEJ-mediated replacement of the gfp with hpt and recovery of hygromycin-resistant plants that no longer expressed GFP and in which the hpt gene was physically linked to the acceptor DNA. Sequence and phenotypical analyses, and transmission of the replacement events to the next generation, confirmed the stability of the NHEJ-induced gene exchange, suggesting its use as a novel method for transgene replacement and gene stacking in plants.

  17. United Kingdom to Join ESO on July 1, 2002

    NASA Astrophysics Data System (ADS)

    2001-12-01

    ESO and PPARC Councils Endorse Terms of Accession [1] The Councils of the European Southern Observatory (ESO) and the UK Particle Physics and Astronomy Research Council (PPARC) , at their respective meetings on December 3 and 5, 2001, have endorsed the terms for UK membership of ESO, as recently agreed by their Negotiating Teams. All members of the Councils - the governing bodies of the two organisations - welcomed the positive spirit in which the extensive negotiations had been conducted and expressed great satisfaction at the successful outcome of a complex process. The formal procedure of accession will now commence in the UK and is expected to be achieved in good time to allow accession from July 2002. The European Southern Observatory is the main European organisation for astronomy and the United Kingdom will become its tenth member state [2]. ESO operates two major observatories in the Chilean Atacama desert where the conditions for astronomical observations are second-to-none on earth and it has recently put into operation the world's foremost optical/infrared telescope, the Very Large Telescope (VLT) at Paranal. With UK membership, British astronomers will join their European colleagues in preparing new projects now being planned on a global scale. They will also be able to pursue their research on some of the most powerful astronomical instruments available. The ESO Director General, Dr. Catherine Cesarsky , is "delighted that we have come this far after the lengthy negotiations needed to prepare properly the admission of another major European country to our organisation. When ESO was created nearly 40 years ago, the UK was planning for its own facilities in the southern hemisphere, in collaboration with Australia, and decided not to join. However, the impressive scientific and technological advances since then and ESOs emergence as a prime player on the European research scene have convinced our UK colleagues of the great advantages of presenting a

  18. N-acetylcysteine amide, a promising antidote for acetaminophen toxicity.

    PubMed

    Khayyat, Ahdab; Tobwala, Shakila; Hart, Marcia; Ercal, Nuran

    2016-01-22

    Acetaminophen (N-acetyl-p-aminophenol, APAP) is one of the most widely used over the counter antipyretic and analgesic medications. It is safe at therapeutic doses, but its overdose can result in severe hepatotoxicity, a leading cause of drug-induced acute liver failure in the USA. Depletion of glutathione (GSH) is one of the initiating steps in APAP-induced hepatotoxicity; therefore, one strategy for restricting organ damage is to restore GSH levels by using GSH prodrugs. N-acetylcysteine (NAC), a GSH precursor, is the only currently approved antidote for an acetaminophen overdose. Unfortunately, fairly high doses and longer treatment times are required due to its poor bioavailability. In addition, oral and I.V. administration of NAC in a hospital setting are laborious and costly. Therefore, we studied the protective effects of N-acetylcysteine amide (NACA), a novel antioxidant with higher bioavailability, and compared it with NAC in APAP-induced hepatotoxicity in C57BL/6 mice. Our results showed that NACA is better than NAC at a low dose (106mg/kg) in preventing oxidative stress and protecting against APAP-induced damage. NACA significantly increased GSH levels and the GSH/GSSG ratio in the liver to 66.5% and 60.5% of the control, respectively; and it reduced the level of ALT by 30%. However, at the dose used, NAC was not effective in combating the oxidative stress induced by APAP. Thus, NACA appears to be better than NAC in reducing the oxidative stress induced by APAP. It would be of great value in the health care field to develop drugs like NACA as more effective and safer options for the prevention and therapeutic intervention in APAP-induced toxicity.

  19. Cloning of a Novel Arylamidase Gene from Paracoccus sp. Strain FLN-7 That Hydrolyzes Amide Pesticides

    PubMed Central

    Zhang, Jun; Yin, Jin-Gang; Hang, Bao-Jian; Cai, Shu; Li, Shun-Peng

    2012-01-01

    The bacterial isolate Paracoccus sp. strain FLN-7 hydrolyzes amide pesticides such as diflubenzuron, propanil, chlorpropham, and dimethoate through amide bond cleavage. A gene, ampA, encoding a novel arylamidase that catalyzes the amide bond cleavage in the amide pesticides was cloned from the strain. ampA contains a 1,395-bp open reading frame that encodes a 465-amino-acid protein. AmpA was expressed in Escherichia coli BL21 and homogenously purified using Ni-nitrilotriacetic acid affinity chromatography. AmpA is a homodimer with an isoelectric point of 5.4. AmpA displays maximum enzymatic activity at 40°C and a pH of between 7.5 and 8.0, and it is very stable at pHs ranging from 5.5 to 10.0 and at temperatures up to 50°C. AmpA efficiently hydrolyzes a variety of secondary amine compounds such as propanil, 4-acetaminophenol, propham, chlorpropham, dimethoate, and omethoate. The most suitable substrate is propanil, with Km and kcat values of 29.5 μM and 49.2 s−1, respectively. The benzoylurea insecticides (diflubenzuron and hexaflumuron) are also hydrolyzed but at low efficiencies. No cofactor is needed for the hydrolysis activity. AmpA shares low identities with reported arylamidases (less than 23%), forms a distinct lineage from closely related arylamidases in the phylogenetic tree, and has different biochemical characteristics and catalytic kinetics with related arylamidases. The results in the present study suggest that AmpA is a good candidate for the study of the mechanism for amide pesticide hydrolysis, genetic engineering of amide herbicide-resistant crops, and bioremediation of amide pesticide-contaminated environments. PMID:22544249

  20. Phenolic amides are potent inhibitors of De Novo nucleotide biosynthesis

    SciTech Connect

    Pisithkul, Tippapha; Jacobson, Tyler B.; O'Brien, Thomas J.; Stevenson, David M.; Amador-Noguez, Daniel

    2015-06-12

    An outstanding challenge toward efficient production of biofuels and value-added chemicals from plant biomass is the impact that lignocellulose-derived inhibitors have on microbial fermentations. Elucidating the mechanisms that underlie their toxicity is critical for developing strategies to overcome them. Here, using Escherichia coli as a model system, we investigated the metabolic effects and toxicity mechanisms of feruloyl amide and coumaroyl amide, the predominant phenolic compounds in ammonia-pretreated biomass hydrolysates. Using metabolomics, isotope tracers, and biochemical assays, we showed that these two phenolic amides act as potent and fast-acting inhibitors of purine and pyrimidine biosynthetic pathways. Feruloyl or coumaroyl amide exposure leads to (i) a rapid buildup of 5-phosphoribosyl-1-pyrophosphate (PRPP), a key precursor in nucleotide biosynthesis, (ii) a rapid decrease in the levels of pyrimidine biosynthetic intermediates, and (iii) a long-term generalized decrease in nucleotide and deoxynucleotide levels. Tracer experiments using 13C-labeled sugars and [15N]ammonia demonstrated that carbon and nitrogen fluxes into nucleotides and deoxynucleotides are inhibited by these phenolic amides. We found that these effects are mediated via direct inhibition of glutamine amidotransferases that participate in nucleotide biosynthetic pathways. In particular, feruloyl amide is a competitive inhibitor of glutamine PRPP amidotransferase (PurF), which catalyzes the first committed step in de novo purine biosynthesis. Finally, external nucleoside supplementation prevents phenolic amide-mediated growth inhibition by allowing nucleotide biosynthesis via salvage pathways. Furthermore, the results presented here will help in the development of strategies to overcome toxicity of phenolic compounds and facilitate engineering of more efficient microbial producers of biofuels and chemicals.

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

    SciTech Connect

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

    2014-05-01

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

  2. Direct thionation and selenation of amides using elemental sulfur and selenium and hydrochlorosilanes in the presence of amines.

    PubMed

    Shibahara, Fumitoshi; Sugiura, Rie; Murai, Toshiaki

    2009-07-16

    Reactions of amides with elemental sulfur in the presence of hydrochlorosilanes and amines give the corresponding thioamides in good to high yields. The process takes place via reduction of elemental sulfur by the hydrochlorosilane in the presence of a suitable amine. The methodology can be applied to the selenation of amides by using elemental selenium. Thionation and selenation of an acetyl-protected sialic acid derivative are found to take place selectively at the amide group.

  3. Sterically-controlled intermolecular Friedel-Crafts acylation with twisted amides via selective N-C cleavage under mild conditions.

    PubMed

    Liu, Yongmei; Meng, Guangrong; Liu, Ruzhang; Szostak, Michal

    2016-05-21

    Highly chemoselective Friedel-Crafts acylation with twisted amides under mild conditions is reported for the first time. The reaction shows high functional group tolerance, obviating the need for preformed sensitive organometallic reagents and expensive transition metal catalysts. The high reactivity of amides is switched on by ground-state steric distortion to disrupt the amide bond nN→πCO* resonance as a critical design feature. Conceptually, this new acid-promoted mechanism of twisted amides provides direct access to bench-stable acylating reagents under mild, metal-free conditions.

  4. A New Approach to Joining of Silicon Carbide-Based Materials for High Temperature Applications

    NASA Technical Reports Server (NTRS)

    Singh, Mrityunjay

    1998-01-01

    Ceramic joining is recognized as one of the enabling technologies for the application of silicon carbide-based materials in a number of high temperature applications. An affordable, robust technique for the joining of silicon carbide-based ceramics has been developed. This technique is capable of producing joints with tailorable thickness and composition. Microstructure and mechanical properties of reaction formed joints in a reaction bonded silicon carbide have been reported. These joints maintain their mechanical strengths at high temperatures (up to 1350 C) in air. This technique is capable of joining large and complex shaped ceramic components.

  5. The impulse resistance welding: A new technique for joining advanced thermoplastic composite parts

    SciTech Connect

    Arias, M.; Ziegmann, G.

    1996-12-31

    Welding is a joining technique suitable for thermoplastic composites. This paper presents the development of a new, fast joining technique, which is based on the common resistance welding process. Heat is introduced by using electrical power pulses into the heating area and therefore this technique was called the Impulse Resistance Welding (IRW). The new technique will be described and discussed and the application of this technique by joining ribs to the skin of an aerodynamic spoiler part is demonstrated. The potential of an automation of the Impulse resistance welding process will be shown. Carbon fibre /PEEK (APC-2/AS4) has been selected as the material both for the skin and the rib.

  6. Cryptic signals and the fidelity of V(D)J joining.

    PubMed Central

    Lewis, S M; Agard, E; Suh, S; Czyzyk, L

    1997-01-01

    V(D)J recombination is responsible for the de novo creation of antigen receptor genes in T- and B-cell precursors. To the extent that lymphopoiesis takes place throughout an animal's lifetime, recombination errors present an ongoing problem. One type of aberrant rearrangement ensues when DNA sequences resembling a V(D)J joining signal are targeted by mistake. This study investigates the type of sequence likely to be subject to mistargeting, the level of joining-signal function associated with these sequences, and the number of such cryptic joining signals in the genome. PMID:9154811

  7. Joining of Silicon Carbide-Based Ceramic Materials for High Temperature Applications

    NASA Technical Reports Server (NTRS)

    Singh, Mrityunjay

    1997-01-01

    Joining of high temperature silicon carbide-based ceramics has been a critical issue for their successful application. An affordable, robust technique for joining silicon carbide-based ceramics has been developed and is capable of producing joints that can be tailored for thickness and composition. These joints maintain their mechanical strength up to 1350 C (2462 F) in air. This technique is suitable for the joining of large and complex shaped ceramic components and can be extended to the repair of these materials.

  8. Gas-Phase Amidation of Carboxylic Acids with Woodward's Reagent K Ions

    NASA Astrophysics Data System (ADS)

    Peng, Zhou; Pilo, Alice L.; Luongo, Carl A.; McLuckey, Scott A.

    2015-06-01

    Gas-phase amidation of carboxylic acids in multiply-charged peptides is demonstrated via ion/ion reactions with Woodward's reagent K (wrk) in both positive and negative mode. Woodward's reagent K, N-ethyl-3-phenylisoxazolium-3'-sulfonate, is a commonly used reagent that activates carboxylates to form amide bonds with amines in solution. Here, we demonstrate that the analogous gas-phase chemistry occurs upon reaction of the wrk ions and doubly protonated (or doubly deprotonated) peptide ions containing the carboxylic acid functionality. The reaction involves the formation of the enol ester intermediate in the electrostatic complex. Upon collisional activation, the ethyl amine on the reagent is transferred to the activated carbonyl carbon on the peptide, resulting in the formation of an ethyl amide (addition of 27 Da to the peptide) with loss of a neutral ketene derivative. Further collision-induced dissociation (CID) of the products and comparison with solution-phase amidation product confirms the structure of the ethyl amide.

  9. Noninvasive amide proton transfer magnetic resonance imaging in evaluating the grading and cellularity of gliomas

    PubMed Central

    Zhang, Wei; Kong, Lingfei; Wang, Lifu; Zuo, Panli; Vallines, Ignacio; Schmitt, Benjamin; Tian, Jie; Song, Xiaolei; Zhou, Jinyuan; Wang, Meiyun

    2017-01-01

    Using noninvasive magnetic resonance imaging techniques to accurately evaluate the grading and cellularity of gliomas is beneficial for improving the patient outcomes. Amide proton transfer imaging is a noninvasive molecular magnetic resonance imaging technique based on chemical exchange saturation transfer mechanism that detects endogenous mobile proteins and peptides in biological tissues. Between August 2012 and November 2015, a total number of 44 patients with pathologically proven gliomas were included in this study. We compared the capability of amide proton transfer magnetic resonance imaging with that of noninvasive diffusion-weighted imaging and noninvasive 3-dimensional pseudo-continuous arterial spin imaging in evaluating the grading and cellularity of gliomas. Our results reveal that amide proton transfer magnetic resonance imaging is a superior imaging technique to diffusion-weighted imaging and 3-dimensional pseudo-continuous arterial spin imaging in the grading of gliomas. In addition, our results showed that the Ki-67 index correlated better with the amide proton transfer-weighted signal intensity than with the apparent diffusion coefficient value or the cerebral blood flow value in the gliomas. Amide proton transfer magnetic resonance imaging is a promising method for predicting the grading and cellularity of gliomas. PMID:27992380

  10. Noninvasive amide proton transfer magnetic resonance imaging in evaluating the grading and cellularity of gliomas.

    PubMed

    Bai, Yan; Lin, Yusong; Zhang, Wei; Kong, Lingfei; Wang, Lifu; Zuo, Panli; Vallines, Ignacio; Schmitt, Benjamin; Tian, Jie; Song, Xiaolei; Zhou, Jinyuan; Wang, Meiyun

    2017-01-24

    Using noninvasive magnetic resonance imaging techniques to accurately evaluate the grading and cellularity of gliomas is beneficial for improving the patient outcomes. Amide proton transfer imaging is a noninvasive molecular magnetic resonance imaging technique based on chemical exchange saturation transfer mechanism that detects endogenous mobile proteins and peptides in biological tissues. Between August 2012 and November 2015, a total number of 44 patients with pathologically proven gliomas were included in this study. We compared the capability of amide proton transfer magnetic resonance imaging with that of noninvasive diffusion-weighted imaging and noninvasive 3-dimensional pseudo-continuous arterial spin imaging in evaluating the grading and cellularity of gliomas. Our results reveal that amide proton transfer magnetic resonance imaging is a superior imaging technique to diffusion-weighted imaging and 3-dimensional pseudo-continuous arterial spin imaging in the grading of gliomas. In addition, our results showed that the Ki-67 index correlated better with the amide proton transfer-weighted signal intensity than with the apparent diffusion coefficient value or the cerebral blood flow value in the gliomas. Amide proton transfer magnetic resonance imaging is a promising method for predicting the grading and cellularity of gliomas.

  11. Electrostatic frequency shifts in amide I vibrational spectra: Direct parameterization against experiment

    NASA Astrophysics Data System (ADS)

    Reppert, Mike; Tokmakoff, Andrei

    2013-04-01

    The interpretation of protein amide I infrared spectra has been greatly assisted by the observation that the vibrational frequency of a peptide unit reports on its local electrostatic environment. However, the interpretation of spectra remains largely qualitative due to a lack of direct quantitative connections between computational models and experimental data. Here, we present an empirical parameterization of an electrostatic amide I frequency map derived from the infrared absorption spectra of 28 dipeptides. The observed frequency shifts are analyzed in terms of the local electrostatic potential, field, and field gradient, evaluated at sites near the amide bond in molecular dynamics simulations. We find that the frequency shifts observed in experiment correlate very well with the electric field in the direction of the C=O bond evaluated at the position of the amide oxygen atom. A linear best-fit mapping between observed frequencies and electric field yield sample standard deviations of 2.8 and 3.7 cm-1 for the CHARMM27 and OPLS-AA force fields, respectively, and maximum deviations (within our data set) of 9 cm-1. These results are discussed in the broader context of amide I vibrational models and the effort to produce quantitative agreement between simulated and experimental absorption spectra.

  12. Optimization of Amide-Based Inhibitors of Soluble Epoxide Hydrolase with Improved Water Solubility

    PubMed Central

    Kim, In-Hae; Heirtzler, Fenton R.; Morisseau, Christophe; Nishi, Kosuke; Tsai, Hsing-Ju; Hammock, Bruce D.

    2006-01-01

    Soluble epoxide hydrolase (sEH) plays an important role in the metabolism of endogenous chemical mediators involved in the regulation of blood pressure and inflammation. 1,3-Disubstituted ureas with a polar group located on the fifth atom from the carbonyl group of urea function are active inhibitors of sEH both in vitro and in vivo. However, their limited solubility in water and relatively high melting point lead to difficulties in formulating the compounds and poor in vivo efficacy. To improve these physical properties, the effect of structural modification of the urea pharmacophore on the inhibition potencies, water solubilities, octanol/water partition coefficients (log P), and melting points of a series of compounds was evaluated. For murine sEH, no loss of inhibition potency was observed when the urea pharmacophore was modified to an amide function, while for human sEH 2.5-fold decreased inhibition was obtained in the amide compounds. In addition, a NH group on the right side of carbonyl group of the amide pharmacophore substituted with an adamantyl group (such as compound 14) and a methylene carbon present between the adamantyl and amide groups were essential to produce potent inhibition of sEH. The resulting amide inhibitors have 10–30-fold better solubility and lower melting point than the corresponding urea compounds. These findings will facilitate synthesis of sEH inhibitors that are easier to formulate and more bioavailable. PMID:15887969

  13. Chain-length and mode-delocalization dependent amide-I anharmonicity in peptide oligomers.

    PubMed

    Zhao, Juan; Wang, Jianping

    2012-06-07

    The diagonal anharmonicities of the amide-I mode in the alanine oligomers are examined in the normal-mode basis by ab initio calculations. The selected oligomers range from dimer to heptamer, in either the α-helical or β-sheet conformations. It is found that the anharmonicity varies from mode to mode within the same oligomer. For a given amide-I mode, the anharmonicity is closely related to the delocalization extent of the mode: the less it delocalizes, the larger the anharmonicity it has. Thus, the single-mode potential energy distribution (PED(max)) can be used as an indicator of the magnitude of the anharmonicity. It is found that as the peptide chain length increases, the averaged diagonal anharmonicity generally decreases; however, the sum of the averaged diagonal and off-diagonal anharmonicities within a peptide roughly remains a constant for all the oligomers examined, indicating the excitonic characteristics of the amide-I modes. Excitonic coupling tends to decrease the diagonal anharmonicities in a coupled system with multiple chromophores, which explains the observed behavior of the anharmonicities. The excitonic nature of the amide-I band in peptide oligomers is thus verified by the anharmonic computations. Isotopic substitution effect on the anharmonicities and mode localizations of the amide-I modes in peptides is also discussed.

  14. The amide protonation of (-)-N-benzoylcytisine in its perchlorate salts

    NASA Astrophysics Data System (ADS)

    Przybył, Anna K.; Kubicki, Maciej; Hoffmann, Marcin

    2014-08-01

    The 13C NMR spectrum of (-)-N-benzoylcytisine perchlorate does not show a double set of signals typical of amide compounds, although this effect has been observed for the other diamine derivatives of cytisine. This observation means that in solution there must be the state of equilibrium between two forms of the cation with the protonated amide groups. DFT calculations have indeed indicated two preferred tautomeric forms with protonated oxygen atoms of amide groups. In the solid state however, according to X-ray analysis of perchlorate and perchlorate hydrate of N-benzoylcytisine the oxygen atom of the amide group in the six-membered ring A is preferred protonation site as compared with the oxygen in benzoic moiety. (-)-N-benzoylcytisine salt is the first compound from among the known derivatives of quinolizidine alkaloids that are not N-oxides, in which in solid state only the oxygen atom at cyclic amide is protonated instead of nitrogen atom or oxygen in benzoic moiety.

  15. Electrostatic frequency shifts in amide I vibrational spectra: Direct parameterization against experiment

    PubMed Central

    Reppert, Mike; Tokmakoff, Andrei

    2013-01-01

    The interpretation of protein amide I infrared spectra has been greatly assisted by the observation that the vibrational frequency of a peptide unit reports on its local electrostatic environment. However, the interpretation of spectra remains largely qualitative due to a lack of direct quantitative connections between computational models and experimental data. Here, we present an empirical parameterization of an electrostatic amide I frequency map derived from the infrared absorption spectra of 28 dipeptides. The observed frequency shifts are analyzed in terms of the local electrostatic potential, field, and field gradient, evaluated at sites near the amide bond in molecular dynamics simulations. We find that the frequency shifts observed in experiment correlate very well with the electric field in the direction of the C=O bond evaluated at the position of the amide oxygen atom. A linear best-fit mapping between observed frequencies and electric field yield sample standard deviations of 2.8 and 3.7 cm−1 for the CHARMM27 and OPLS-AA force fields, respectively, and maximum deviations (within our data set) of 9 cm−1. These results are discussed in the broader context of amide I vibrational models and the effort to produce quantitative agreement between simulated and experimental absorption spectra. PMID:23574217

  16. Measurement of amide hydrogen exchange rates with the use of radiation damping.

    PubMed

    Fan, Jing-Song; Lim, Jackwee; Yu, Binhan; Yang, Daiwen

    2011-09-01

    A simple method for measuring amide hydrogen exchange rates is presented, which is based on the selective inversion of water magnetization with the use of radiation damping. Simulations show that accurate exchange rates can be measured despite the complications of radiation damping and cross relaxation to the exchange process between amide and water protons. This method cannot eliminate the contributions of the exchange-relayed NOE and direct NOE to the measured exchange rates, but minimize the direct NOE contribution. In addition, the amides with a significant amount of such indirect contributions are possible to be identified from the shape of the exchange peak intensity profiles or/and from the apparent relaxation rates of amide protons which are extracted from fitting the intensity profiles to an equation established here for our experiment. The method was tested on ubiquitin and also applied to an acyl carrier protein. The amide exchange rates for the acyl carrier protein at two pHs indicate that the entire protein is highly dynamic on the second timescale. Low protection factors for the residues in the regular secondary structural elements also suggest the presence of invisible unfolded species. The highly dynamic nature of the acyl carrier protein may be crucial for its interactions with its substrate and enzymes.

  17. A comparative study of the complexation of uranium(VI) withoxydiacetic acid and its amide derivatives

    SciTech Connect

    Rao, Linfeng; Tian, Guoxin

    2005-05-01

    There has been significant interest in recent years in the studies of alkyl-substituted amides as extractants for actinide separation because the products of radiolytic and hydrolytic degradation of amides are less detrimental to separation processes than those of organophosphorus compounds traditionally used in actinide separations. Stripping of actinides from the amide-containing organic solvents is relatively easy. In addition, the amide ligands are completely incinerable so that the amount of secondary wastes generated in nuclear waste treatment could be significantly reduced. One group of alkyl-substituted oxa-diamides have been shown to be promising in the separation of actinides from nuclear wastes. For example, tetraoctyl-3-oxa-glutaramide and tetraisobutyl-oxa-glutaramide form actinide complexes that can be effectively extracted from nitric acid solutions. To understand the thermodynamic principles governing the complexation of actinides with oxa-diamides, we have studied the complexation of U(VI) with dimethyl-3-oxa-glutaramic acid (DMOGA) and tetramethyl-3-oxa-glutaramide (TMOGA) in aqueous solutions, in comparison with oxydiacetic acid (ODA) (Figure 1). Previous studies have indicated that the complexation of U(VI) with ODA is strong and entropy-driven. Comparing the results for DMOGA and TMOGA with those for ODA could provide insight into the energetics of amide complexation with U(VI) and the relationship between the thermodynamic properties and the ligand structure.

  18. 30 CFR 1290.106 - How do lessees join a designee's appeal and how does joinder affect the appeal?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 3 2014-07-01 2014-07-01 false How do lessees join a designee's appeal and how... REVENUE, DEPARTMENT OF THE INTERIOR APPEALS APPEAL PROCEDURES § 1290.106 How do lessees join a designee's... under § 1290.103, you may join in that appeal within 30 days after you receive your designee's Notice...

  19. 26 CFR 1.1502-98A - Coordination with section 383 generally applicable for testing dates (or members joining or...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... applicable for testing dates (or members joining or leaving a group) before June 25, 1999. 1.1502-98A Section... Dates (and Corporations Joining Or Leaving Consolidated Groups) Before June 25, 1999 § 1.1502-98A Coordination with section 383 generally applicable for testing dates (or members joining or leaving a...

  20. 26 CFR 1.1502-98A - Coordination with section 383 generally applicable for testing dates (or members joining or...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... applicable for testing dates (or members joining or leaving a group) before June 25, 1999. 1.1502-98A Section... Dates (and Corporations Joining Or Leaving Consolidated Groups) Before June 25, 1999 § 1.1502-98A Coordination with section 383 generally applicable for testing dates (or members joining or leaving a...

  1. 30 CFR 1290.106 - How do lessees join a designee's appeal and how does joinder affect the appeal?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 3 2011-07-01 2011-07-01 false How do lessees join a designee's appeal and how... join a designee's appeal and how does joinder affect the appeal? (a) If you are a lessee, and your designee files an appeal under § 1290.103, you may join in that appeal within 30 days after you...

  2. 26 CFR 1.1502-98A - Coordination with section 383 generally applicable for testing dates (or members joining or...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... applicable for testing dates (or members joining or leaving a group) before June 25, 1999. 1.1502-98A Section... Corporations Joining Or Leaving Consolidated Groups) Before June 25, 1999 § 1.1502-98A Coordination with section 383 generally applicable for testing dates (or members joining or leaving a group) before June...

  3. 30 CFR 1290.106 - How do lessees join a designee's appeal and how does joinder affect the appeal?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 3 2013-07-01 2013-07-01 false How do lessees join a designee's appeal and how... REVENUE, DEPARTMENT OF THE INTERIOR APPEALS APPEAL PROCEDURES § 1290.106 How do lessees join a designee's... under § 1290.103, you may join in that appeal within 30 days after you receive your designee's Notice...

  4. 26 CFR 1.1502-98A - Coordination with section 383 generally applicable for testing dates (or members joining or...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... applicable for testing dates (or members joining or leaving a group) before June 25, 1999. 1.1502-98A Section... Dates (and Corporations Joining Or Leaving Consolidated Groups) Before June 25, 1999 § 1.1502-98A Coordination with section 383 generally applicable for testing dates (or members joining or leaving a...

  5. 30 CFR 290.106 - How do lessees join a designee's appeal and how does joinder affect the appeal?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false How do lessees join a designee's appeal and how... How do lessees join a designee's appeal and how does joinder affect the appeal? (a) If you are a lessee, and your designee files an appeal under § 290.103, you may join in that appeal within 30...

  6. 26 CFR 1.1502-98A - Coordination with section 383 generally applicable for testing dates (or members joining or...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... applicable for testing dates (or members joining or leaving a group) before June 25, 1999. 1.1502-98A Section... Dates (and Corporations Joining Or Leaving Consolidated Groups) Before June 25, 1999 § 1.1502-98A Coordination with section 383 generally applicable for testing dates (or members joining or leaving a...

  7. 30 CFR 1290.106 - How do lessees join a designee's appeal and how does joinder affect the appeal?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 3 2012-07-01 2012-07-01 false How do lessees join a designee's appeal and how... REVENUE, DEPARTMENT OF THE INTERIOR APPEALS APPEAL PROCEDURES § 1290.106 How do lessees join a designee's... under § 1290.103, you may join in that appeal within 30 days after you receive your designee's Notice...

  8. Quinolone Amides as Antitrypanosomal Lead Compounds with In Vivo Activity

    PubMed Central

    Hiltensperger, Georg; Hecht, Nina; Kaiser, Marcel; Rybak, Jens-Christoph; Hoerst, Alexander; Dannenbauer, Nicole; Müller-Buschbaum, Klaus; Bruhn, Heike; Esch, Harald; Lehmann, Leane; Meinel, Lorenz

    2016-01-01

    Human African trypanosomiasis (HAT) is a major tropical disease for which few drugs for treatment are available, driving the need for novel active compounds. Recently, morpholino-substituted benzyl amides of the fluoroquinolone-type antibiotics were identified to be compounds highly active against Trypanosoma brucei brucei. Since the lead compound GHQ168 was challenged by poor water solubility in previous trials, the aim of this study was to introduce structural variations to GHQ168 as well as to formulate GHQ168 with the ultimate goal to increase its aqueous solubility while maintaining its in vitro antitrypanosomal activity. The pharmacokinetic parameters of spray-dried GHQ168 and the newly synthesized compounds GHQ242 and GHQ243 in mice were characterized by elimination half-lives ranging from 1.5 to 3.5 h after intraperitoneal administration (4 mice/compound), moderate to strong human serum albumin binding for GHQ168 (80%) and GHQ243 (45%), and very high human serum albumin binding (>99%) for GHQ242. For the lead compound, GHQ168, the apparent clearance was 112 ml/h and the apparent volume of distribution was 14 liters/kg of body weight (BW). Mice infected with T. b. rhodesiense (STIB900) were treated in a stringent study scheme (2 daily applications between days 3 and 6 postinfection). Exposure to spray-dried GHQ168 in contrast to the control treatment resulted in mean survival durations of 17 versus 9 days, respectively, a difference that was statistically significant. Results that were statistically insignificantly different were obtained between the control and the GHQ242 and GHQ243 treatments. Therefore, GHQ168 was further profiled in an early-treatment scheme (2 daily applications at days 1 to 4 postinfection), and the results were compared with those obtained with a control treatment. The result was statistically significant mean survival times exceeding 32 days (end of the observation period) versus 7 days for the GHQ168 and control treatments

  9. Supercomputers Join the Fight against Cancer – U.S. Department of Energy

    SciTech Connect

    2016-06-29

    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.

  10. Simulation of a Novel Joining Process for Fiber-Reinforced Thermoplastic Composites and Metallic Components

    NASA Astrophysics Data System (ADS)

    Gude, M.; Freund, A.; Vogel, C.; Kupfer, R.

    2017-01-01

    In this study, a new joining technology to produce hybrid structures with continuous-fiber-reinforced thermoplastics and metallic components is presented adapting the concept of classical clinching for thermoplastic composites. To demonstrate the capability of the thermoclinching process, prototypic joints were manufactured using an experimental joining installation developed. Nondestructive and destructive analyses of the thermoclinched joints showed that a relocation of the reinforcement into the neck and head area of the joining zone could be achieved. For a first estimation of the maximum load-carrying capacity of the joints, single-lap specimens with both reinforced and nonreinforced thermoplastics were manufactured and tested, revealing up to 50% higher failure loads of the reinforced joints. To understand the local material configuration and to achieve a defined and adjustable fabric structure in the head area of the joint, further analyses with regard to material- and tool-side conditions of the joining zone are necessary.

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

    PubMed

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

    2009-01-23

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

  12. 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.

  13. Finite Element Simulation of Plastic Joining Processes of Steel and Aluminum Alloy Sheets

    SciTech Connect

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

    2007-05-17

    Various high tensile strength steel sheets and an aluminum alloy sheet were joined with a self-piercing rivet. It is not easy to weld the aluminum alloy sheet and high tensile strength sheets by means of conventional resistance welding because of very different melting points. To obtain optimum joining conditions, joining defects were categorized into separation of the sheets and an inner fracture. The joining range of ultra high tensile strength steel and aluminum alloy sheets was extended by means of dies optimized by finite element simulation. The joint strength is greatly influenced by not only the strength of the sheets and rivets but also the ratio of the thickness of the lower sheet to the total thickness. In addition, mechanical clinching of high strength steel and aluminum alloy sheets was simulated.

  14. Finite Element Simulation of Plastic Joining Processes of Steel and Aluminum Alloy Sheets

    NASA Astrophysics Data System (ADS)

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

    2007-05-01

    Various high tensile strength steel sheets and an aluminum alloy sheet were joined with a self-piercing rivet. It is not easy to weld the aluminum alloy sheet and high tensile strength sheets by means of conventional resistance welding because of very different melting points. To obtain optimum joining conditions, joining defects were categorized into separation of the sheets and an inner fracture. The joining range of ultra high tensile strength steel and aluminum alloy sheets was extended by means of dies optimized by finite element simulation. The joint strength is greatly influenced by not only the strength of the sheets and rivets but also the ratio of the thickness of the lower sheet to the total thickness. In addition, mechanical clinching of high strength steel and aluminum alloy sheets was simulated.

  15. Ames Director William 'Bill' Ballhaus (center left) joins visitor Sir Jeffrey Pope from Royla

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Ames Director William 'Bill' Ballhaus (center left) joins visitor Sir Jeffrey Pope from Royla Aircraft Industry, England (center right) at the NAS Facility Cray 2 computer with Ron Deiss, NAS Deputy Manager (L) and Vic Peterson, Ames Deputy Director (R).

  16. The joining of blunt to 3' protruding-single-strands inEscherichia coli

    SciTech Connect

    King, J.; Fairley, C.; Morgan, W.

    1997-11-21

    In eukaryotic and prokaryotic organisms DNA double-strandbreaks with non-complementary ends can be joined by mechanisms ofillegitimate recombination. We examined the joining of 3'-protrudingsingle strand (PSS) ends, which do not have recessed 3' hydroxyls thatcan allow for fill-in DNA synthesis, to blunt ends. End-joining wasexamined by electro-transforming Escherichia coli strains with linearizedplasmid DNA, sequencing the resulting junctions, and determining thetransformation frequencies. Three different E. coli strains wereexamined: MC1061, which has no known recombination or DNA repair defects,HB101 (rec A-) and SURE (recB- recJ-). No striking differences were foundin either the spectrum of products observed or the efficiency ofend-joining between these strains. As in vertebrate systems, the majorityof the products were overlaps between directly repeated DNA sequences.3'-PSS are frequently preserved in vertebrate systems, but they were notpreserved in our experiments unless the transforming DNA was pretreatedwith a DNA polymerase.

  17. TODAY: EPA Administrator Joins Senior Administration Officials at White House for Climate and Health Event

    EPA Pesticide Factsheets

    W ASHINGTON- Today, during National Public Health Week, EPA Administrator Gina McCarthy will join senior Obama Administration officials and representatives from the public and private sectors at the White House for a climate and public health

  18. A review of semi-solid aluminium-steel joining processes

    NASA Astrophysics Data System (ADS)

    Obeidi, Muhannad; McCarthy, Éanna; Brabazon, Dermot

    2016-10-01

    The semi-solid metal (SSM) forming process can be applied to achieve near net shape forming of metal alloys, and provides superior component properties compared to those achievable with conventional casting methods. The technique, also commonly called thixoforming, relies on achieving a spheroidal microstructure within the metal alloy so that its fluidity can be adjusted to achieve a controlled laminar filling of the die. Despite the better quality and the higher mechanical properties of an SSM product, thixoforming still represents only 1% of the total aluminium production, which can be explained by the higher premium cost of the processing equipment compared to conventional die casting. The method has also proven successful as a joining method, for joining similar and dissimilar materials. This paper reviews semisolid forming as a forming method and as a joining method, in particular the joining of dissimilar materials such as stainless steel to aluminium.

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

    SciTech Connect

    MJ Lambert

    2005-11-18

    Under the direction of the NASA-Glenn Research Center, the Edison Welding Institute (EWI) in Columbus, OH performed a series of non-fusion joining experiments to determine the feasibility of joining refractory metals or refractory metal alloys to Ni-based superalloys. Results, as reported by EWI, can be found in the project report for EWI Project 48819GTH (Attachment A, at the end of this document), dated October 10, 2005. The three joining methods used in this investigation were inertia welding, magnetic pulse welding, and electro-spark deposition joining. Five materials were used in these experiments: Mo-47Re, T-111, Hastelloy X, Mar M-247 (coarse-grained, 0.5 mm to several millimeter average grain size), and Mar M-247 (fine-grained, approximately 50 {micro}m average grain size). Several iterative trials of each material combination with each joining method were performed to determine the best practice joining method. Mo-47Re was found to be joined easily to Hastelloy X via inertia welding, but inertia welding of the Mo-alloy to both Mar M-247 alloys resulted in inconsistent joint strength and large reaction layers between the two metals. T-111 was found to join well to Hastelloy X and coarse-grained Mar M-247 via inertia welding, but joining to fine-grained Mar M-247 resulted in low joint strength. Magnetic pulse welding (MPW) was only successful in joining T-111 tubing to Hastelloy X bar stock. The joint integrity and reaction layer between the metals were found to be acceptable. This single joining trial, however, caused damage to the electromagnetic concentrators used in this process. Subsequent design efforts to eliminate the problem resulted in a loss of power imparted to the accelerating work piece, and results could not be reproduced. Welding trials of Mar M-247 to T-111 resulted in catastrophic failure of the bar stock, even at lower power. Electro-spark deposition joining of Mo-47Re, in which the deposited material was Hastelloy X, did not have a

  20. Joining conditions for cosmological perturbations at an equation-of-state transition

    SciTech Connect

    Ratra, B. )

    1991-06-15

    Joining conditions for cosmological spatial irregularities at an equation-of-state transition spatial hypersurface are derived by requiring that the relativistic linear perturbation theory equations of motion remain singularity-free at the transition spatial hypersurface. The transition spatial hypersurface is taken to be a spatially homogeneous local energy-density spatial hypersurface, between two spacetime-dependent speed-of-sound'' fluid-dominated epochs of a spatially flat Friedmann-Lema{cflx i}tre-Robertson-Walker cosmological model. Since the spacetime-dependent speed-of-sound'' fluid model includes, as special cases, both the scalar field model and the ideal fluid model, these joining conditions may be used at the scalar-field--radiation and radiation-baryon transitions in simple inflation-modified hot big-bang models. These joining conditions differ from two earlier sets of joining conditions (which differ from each other).

  1. EPA, USDA Join to Set Nations First Food Waste Reduction Goals with Charities and Private Companies

    EPA Pesticide Factsheets

    WASHINGTON -- On Wednesday, September 16, U.S. Environmental Protection Agency (EPA) Acting Deputy Administrator Stan Meiberg will join U.S. Agriculture Secretary Tom Vilsack as well as private industry and charitable organizations to announce the U

  2. Dissociation of POMC Peptides after Self-Injury Predicts Responses To Centrally Acting Opiate Blockers.

    ERIC Educational Resources Information Center

    Sandman, Curt A.; Hetrick, William; Taylor, Derek V.; Chicz-DeMet, Aleksandra

    1997-01-01

    This study investigated whether blood plasma levels of pro-opiomelanocortin-derived (POMC) peptides, beta-endorphin-like activity, adrenocorticotrophic hormone, and adrenal cortisol immediately after self injurious behavior (SIB) episodes predicted subsequent response to an opiate blocker in 10 patients with mental retardation. Results suggest…

  3. Europlanet - Joining the European Planetary Research Information Service

    NASA Astrophysics Data System (ADS)

    Capria, M. T.; Chanteur, G.; Schmidt, W.

    2009-04-01

    The "Europlanet Research Infrastructure - Europlanet RI", supported by the European Commission's Framework Program 7, aims at integrating major parts of the distributed European Planetary Research infrastructure with as diverse components as space exploration, ground-based observations, laboratory experiments and numerical model-ling teams. A central part of Europlanet RI is the "Integrated and Distributed Information Service" or Europlanet-IDIS which intends to provide easy Web-based access to information about scientists and teams working in related fields, observatories or laboratories with capabilities possibly beneficial to planetary research, modelling expertise useful for planetary science and observations from space-based, ground-based or laboratory measurements. As far as the type of data and their access methods allow, IDIS will provide Virtual Observatory (VO) like access to a variety of data from distributed sources and tools to compare and integrate this information to further data analysis and re-search. IDIS itself is providing a platform for information and data sharing and for data mining. It is structured as a network of thematic nodes each concentrating on a sub-set of research areas in planetary sciences. But the most important elements of IDIS and the whole Europlanet RI are the single scientists, institutes, laboratories, observatories and mission project teams. Without them the whole effort would remain an empty shell. How can an interested individual or team join this activity and what are the benefits to be expected from the related effort? The poster gives detailed answers to these questions. Here some highlights: 1. Locate from the Europlanet web pages (addresses see below) the thematic node best related to the own field of expertise. This might be more than one. 2. Define which services you want to offer to the community: just the contact address, field of competence, off-line access to data on request or even on-line searchable access

  4. Space-selective laser joining of dissimilar transparent materials using femtosecond laser pulses

    SciTech Connect

    Watanabe, Wataru; Onda, Satoshi; Tamaki, Takayuki; Itoh, Kazuyoshi; Nishii, Junji

    2006-07-10

    We report on the joining of dissimilar transparent materials based on localized melting and resolidification of the materials only around the focal volume due to nonlinear absorption of focused femtosecond laser pulses. We demonstrate the joining of borosilicate glass and fused silica, whose coefficients of thermal expansion are different. The joint strength and the transmittance through joint volume were investigated by varying the translation velocity of the sample and the pulse energy of the irradiated laser pulses.

  5. Investigation into the joining of MoSi{sub 2} to 316L stainless steel

    SciTech Connect

    Vaidya, R.U.; Bartlett, A.H.; Conzone, S.D.; Butt, D.P.

    1996-10-01

    Partial transient liquid phase joining and low temperature brazing were applied in joining MoSi{sub 2} to 316L ss. Exploratory studies were carried out on various interlayer materials. Mechanical, physical, and chemical compatibilities between various interlayers, brazing material, and substrate materials were investigated. Effect of thermal expansion mismatch between various components of the joint on the overall joint integrity was also studied. Preliminary findings are outlined.

  6. Troubled Journeys: Some Motivations of Young Muslim Men to Join the Islamic State.

    PubMed

    Yordanova, Kalina

    2016-07-04

    Large numbers of young people have joined jihadists groups in the Syrian/Iraqi conflict. Why would these young people decide to become jihadist fighters? What are the representations of the West they hold and how do these representations shape their decision? Drawing on the psychotherapeutic work with Syrian and Iraqi asylum seekers, this paper seeks to explain the most intimate reasons of young Muslim would-be fighters to join the Islamic State militias.

  7. Resolution of complex ends by Nonhomologous end joining - better to be lucky than good?

    PubMed Central

    2012-01-01

    The Nonhomologous end joining pathway is essential for efficient repair of chromosome double strand breaks. This pathway consequently plays a key role in cellular resistance to break-inducing exogenous agents, as well as in the developmentally-programmed recombinations that are required for adaptive immunity. Chromosome breaks often have complex or “dirty” end structures that can interfere with the critical ligation step in this pathway; we review here how Nonhomologous end joining resolves such breaks. PMID:23276302

  8. Translation initiation factor 3 regulates switching between different modes of ribosomal subunit joining.

    PubMed

    MacDougall, Daniel D; Gonzalez, Ruben L

    2015-05-08

    Ribosomal subunit joining is a key checkpoint in the bacterial translation initiation pathway during which initiation factors (IFs) regulate association of the 30S initiation complex (IC) with the 50S subunit to control formation of a 70S IC that can enter into the elongation stage of protein synthesis. The GTP-bound form of IF2 accelerates subunit joining, whereas IF3 antagonizes subunit joining and plays a prominent role in maintaining translation initiation fidelity. The molecular mechanisms through which IF2 and IF3 collaborate to regulate the efficiency of 70S IC formation, including how they affect the dynamics of subunit joining, remain poorly defined. Here, we use single-molecule fluorescence resonance energy transfer to monitor the interactions between IF2 and the GTPase-associated center (GAC) of the 50S subunit during real-time subunit joining reactions in the absence and presence of IF3. In the presence of IF3, IF2-mediated subunit joining becomes reversible, and subunit joining events cluster into two distinct classes corresponding to formation of shorter- and longer-lifetime 70S ICs. Inclusion of IF3 within the 30S IC was also found to alter the conformation of IF2 relative to the GAC, suggesting that IF3's regulatory effects may stem in part from allosteric modulation of IF2-GAC interactions. The results are consistent with a model in which IF3 can exert control over the efficiency of subunit joining by modulating the conformation of the 30S IC, which in turn influences the formation of stabilizing intersubunit contacts and thus the reaction's degree of reversibility.

  9. Identification and Quantification of Potential Anti-inflammatory Hydroxycinnamic Acid Amides from Wolfberry.

    PubMed

    Wang, Siyu; Suh, Joon Hyuk; Zheng, Xi; Wang, Yu; Ho, Chi-Tang

    2017-01-18

    Wolfberry or Goji berry, the fruit of Lycium barbarum, exhibits health-promoting properties that leads to an extensive study of their active components. We synthesized a set of hydroxycinnamic acid amide (HCCA) compounds, including trans-caffeic acid, trans-ferulic acid, and 3,4-dihydroxyhydrocinnamic acid, with extended phenolic amine components as standards to identify and quantify the corresponding compounds from wolfberry and to investigate anti-inflammatory properties of these compounds using in vitro model. With optimized LC-MS/MS and NMR analysis, nine amide compounds were identified from the fruits. Seven of these compounds were identified in this plant for the first time. The amide compounds with a tyramine moiety were the most abundant. In vitro studies indicated that five HCCA compounds showed inhibitory effect on NO production inuded by lipopolysaccharides with IC50 less than 15.08 μM (trans-N-feruloyl dopamine). These findings suggested that wolfberries demonstrated anti-inflammatory properties.

  10. Choline Chloride Catalyzed Amidation of Fatty Acid Ester to Monoethanolamide: A Green Approach.

    PubMed

    Patil, Pramod; Pratap, Amit

    2016-01-01

    Choline chloride catalyzed efficient method for amidation of fatty acid methyl ester to monoethanolamide respectively. This is a solvent free, ecofriendly, 100% chemo selective and economically viable path for alkanolamide synthesis. The Kinetics of amidation of methyl ester were studied and found to be first order with respect to the concentration of ethanolamine. The activation energy (Ea) for the amidation of lauric acid methyl ester catalyzed by choline chloride was found to be 50.20 KJ mol(-1). The 98% conversion of lauric acid monoethanolamide was obtained at 110°C in 1 h with 6% weight of catalyst and 1:1.5 molar ratio of methyl ester to ethanolamine under nitrogen atmosphere.

  11. Synthesis, anticancer and antibacterial activity of salinomycin N-benzyl amides.

    PubMed

    Antoszczak, Michał; Maj, Ewa; Napiórkowska, Agnieszka; Stefańska, Joanna; Augustynowicz-Kopeć, Ewa; Wietrzyk, Joanna; Janczak, Jan; Brzezinski, Bogumil; Huczyński, Adam

    2014-11-25

    A series of 12 novel monosubstituted N-benzyl amides of salinomycin (SAL) was synthesized for the first time and characterized by NMR and FT-IR spectroscopic methods. Molecular structures of three salinomycin derivatives in the solid state were determined using single crystal X-ray method. All compounds obtained were screened for their antiproliferative activity against various human cancer cell lines as well as against the most problematic bacteria strains such as methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus epidermidis (MRSE), and Mycobacterium tuberculosis. Novel salinomycin derivatives exhibited potent anticancer activity against drug-resistant cell lines. Additionally, two N-benzyl amides of salinomycin revealed interesting antibacterial activity. The most active were N-benzyl amides of SAL substituted at -ortho position and the least anticancer active derivatives were those substituted at the -para position.

  12. General Applicable Frequency Map for the Amide-I Mode in β-Peptides.

    PubMed

    Cai, Kaicong; Du, Fenfen; Zheng, Xuan; Liu, Jia; Zheng, Renhui; Zhao, Juan; Wang, Jianping

    2016-02-18

    In this work, a general applicable amide-I vibrational frequency map (GA map) for β-peptides in a number of common solvents was constructed, based on a peptide derivative, N-ethylpropionamide (NEPA). The map utilizes force fields at the ab initio computational level to accurately describe molecular structure and solute-solvent interactions, and also force fields at the molecular mechanics level to take into account long-range solute-solvent interactions. The results indicate that the GA map works reasonably for mapping the vibrational frequencies of the amide-I local-modes for β-peptides, holding promises for understanding the complicated infrared spectra of the amide-I mode in β-polypeptides.

  13. How Sensitive Is the Amide I Vibration of the Polypeptide Backbone to Electric Field?

    PubMed Central

    Oh, Kwang-Im; Fiorin, Giacomo

    2015-01-01

    Site-selective isotopic labelling of amide carbonyls offers a non-perturbative means to introduce a localized infrared probe into proteins. While this strategy has been widely used to investigate various biological questions, the dependence of the underlying amide I vibrational frequency on electric field (or Stark tuning rate) has not been fully determined, which prevents it from being used in a quantitative manner in certain applications. Herein, through the use of experiments and molecular dynamics simulations, the Stark tuning rate of the amide I vibration of an isotopically labeled backbone carbonyl in a transmembrane α-helix is determined to be approximately 1.4 cm−1/(MV/cm). This result provides a quantitative basis for using this vibrational model to assess local electric fields in proteins, among other applications. For instance, using this value, we are able to show that the backbone region of a dipeptide has a surprisingly low dielectric constant. PMID:26419214

  14. Metal-Free C–H Alkyliminylation and Acylation of Alkenes with Secondary Amides

    NASA Astrophysics Data System (ADS)

    Huang, Pei-Qiang; Huang, Ying-Hong; Geng, Hui; Ye, Jian-Liang

    2016-06-01

    Carbon–carbon bond formation by metal-free cross-coupling of two reactants with low reactivity represents a challenge in organic synthesis. Secondary amides and alkenes are two classes of bench-stable compounds. The low electrophilicity of the former and low nucleophilicity of the latter make the direct coupling of these two partners challenging yet highly desirable. We report herein an unprecedented intermolecular reaction of secondary amides with alkenes to afford α,β-unsaturated ketimines or enones, which are versatile intermediates for organic synthesis and are prevalent in bioactive compounds and functional materials. Our strategy relies on the chemoselective activation of the secondary amide with trifluoromethanesulfonic anhydride (Tf2O)/2-fluoropyridine to generate a highly reactive nitrilium intermediate, which reacts efficiently with alkenes. This metal-free synthesis is characterized by its mild reaction conditions, excellent functional group tolerance and chemoselectivity, allowing the preparation of multi-functionalized compounds without using protecting groups.

  15. Catalytic asymmetric direct-type 1,4-addition reactions of simple amides.

    PubMed

    Suzuki, Hirotsugu; Sato, Io; Yamashita, Yasuhiro; Kobayashi, Shū

    2015-04-08

    The development of catalytic asymmetric direct-type reactions of less acidic carbonyl compounds such as amides and esters has been a challenging theme in organic chemistry for decades. Here we describe the asymmetric direct 1,4-addition reactions of simple amides with α,β-unsaturated carbonyl compounds using a catalytic amount of a novel chiral catalyst consisting of a potassium base and a macrocyclic chiral crown ether. The desired 1,5-dicarbonyl compounds were obtained in high yields with excellent diastereo- and enantioselectivities. This is the first example of a highly enantioselective catalytic direct-type reaction of simple amides. In addition, the structure of the chiral potassium catalyst has been investigated by X-ray crystallographic, dynamic (1)H NMR, and MALDI-TOF MS analyses.

  16. Metal-Free C–H Alkyliminylation and Acylation of Alkenes with Secondary Amides

    PubMed Central

    Huang, Pei-Qiang; Huang, Ying-Hong; Geng, Hui; Ye, Jian-Liang

    2016-01-01

    Carbon–carbon bond formation by metal-free cross-coupling of two reactants with low reactivity represents a challenge in organic synthesis. Secondary amides and alkenes are two classes of bench-stable compounds. The low electrophilicity of the former and low nucleophilicity of the latter make the direct coupling of these two partners challenging yet highly desirable. We report herein an unprecedented intermolecular reaction of secondary amides with alkenes to afford α,β-unsaturated ketimines or enones, which are versatile intermediates for organic synthesis and are prevalent in bioactive compounds and functional materials. Our strategy relies on the chemoselective activation of the secondary amide with trifluoromethanesulfonic anhydride (Tf2O)/2-fluoropyridine to generate a highly reactive nitrilium intermediate, which reacts efficiently with alkenes. This metal-free synthesis is characterized by its mild reaction conditions, excellent functional group tolerance and chemoselectivity, allowing the preparation of multi-functionalized compounds without using protecting groups. PMID:27356173

  17. Lipase-catalyzed synthesis of fatty acid amide (erucamide) using fatty acid and urea.

    PubMed

    Awasthi, Neeraj Praphulla; Singh, R P

    2007-01-01

    Ammonolysis of fatty acids to the corresponding fatty acid amides is efficiently catalysed by Candida antartica lipase (Novozym 435). In the present paper lipase-catalysed synthesis of erucamide by ammonolysis of erucic acid and urea in organic solvent medium was studied and optimal conditions for fatty amides synthesis were established. In this process erucic acid gave 88.74 % pure erucamide after 48 hour and 250 rpm at 60 degrees C with 1:4 molar ratio of erucic acid and urea, the organic solvent media is 50 ml tert-butyl alcohol (2-methyl-2-propanol). This process for synthesis is economical as we used urea in place of ammonia or other amidation reactant at atmospheric pressure. The amount of catalyst used is 3 %.

  18. Solvent and conformation dependence of amide I vibrations in peptides and proteins containing proline.

    PubMed

    Roy, Santanu; Lessing, Joshua; Meisl, Georg; Ganim, Ziad; Tokmakoff, Andrei; Knoester, Jasper; Jansen, Thomas L C

    2011-12-21

    We present a mixed quantum-classical model for studying the amide I vibrational dynamics (predominantly CO stretching) in peptides and proteins containing proline. There are existing models developed for determining frequencies of and couplings between the secondary amide units. However, these are not applicable to proline because this amino acid has a tertiary amide unit. Therefore, a new parametrization is required for infrared-spectroscopic studies of proteins that contain proline, such as collagen, the most abundant protein in humans and animals. Here, we construct the electrostatic and dihedral maps accounting for solvent and conformation effects on frequency and coupling for the proline unit. We examine the quality and the applicability of these maps by carrying out spectral simulations of a number of peptides with proline in D(2)O and compare with experimental observations.

  19. Development and Validation of Transferable Amide I Vibrational Frequency Maps for Peptides

    PubMed Central

    Wang, L.; Middleton, C. T.; Zanni, M. T.; Skinner, J. L.

    2012-01-01

    Infrared (IR) spectroscopy of the amide I band has been widely utilized for the analysis of peptides and proteins. Theoretical modeling of IR spectra of proteins requires an accurate and efficient description of the amide I frequencies. In this paper, amide I frequency maps for protein backbone and side chain groups are developed from experimental spectra and vibrational lifetimes of N-methylacetamide and acetamide in different solvents. The frequency maps, along with established nearest-neighbor frequency shift and coupling schemes, are then applied to a variety of peptides in aqueous solution and reproduce experimental spectra well. The frequency maps are designed to be transferable to different environments; therefore, they can be used for heterogeneous systems, such as membrane proteins. PMID:21405034

  20. Joining of Silver Nanomaterials at Low Temperatures: Processes, Properties, and Applications.

    PubMed

    Peng, Peng; Hu, Anming; Gerlich, Adrian P; Zou, Guisheng; Liu, Lei; Zhou, Y Norman

    2015-06-17

    A review is provided, which first considers low-temperature diffusion bonding with silver nanomaterials as filler materials via thermal sintering for microelectronic applications, and then other recent innovations in low-temperature joining are discussed. The theoretical background and transition of applications from micro to nanoparticle (NP) pastes based on joining using silver filler materials and nanojoining mechanisms are elucidated. The mechanical and electrical properties of sintered silver nanomaterial joints at low temperatures are discussed in terms of the key influencing factors, such as porosity and coverage of substrates, parameters for the sintering processes, and the size and shape of nanomaterials. Further, the use of sintered silver nanomaterials for printable electronics and as robust surface-enhanced Raman spectroscopy substrates by exploiting their optical properties is also considered. Other low-temperature nanojoining strategies such as optical welding of silver nanowires (NWs) through a plasmonic heating effect by visible light irradiation, ultrafast laser nanojoining, and ion-activated joining of silver NPs using ionic solvents are also summarized. In addition, pressure-driven joining of silver NWs with large plastic deformation and self-joining of gold or silver NWs via oriented attachment of clean and activated surfaces are summarized. Finally, at the end of this review, the future outlook for joining applications with silver nanomaterials is explored.

  1. 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.

  2. 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.

  3. Robust Joining and Assembly Technologies for Ceramic Matrix Composites: Technical Challenges and Opportunities

    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.

  4. W/Cu joining strengthened by femtosecond laser-induced micron-scale interface structure

    NASA Astrophysics Data System (ADS)

    Jiang, Dafa; Gong, Dingwei; Long, Jiangyou; Fan, Peixun; Zhang, Hongjun; Zhong, Minlin

    2016-11-01

    W/Cu joining is key for the fabrication of high heat load components for fusion reactors, which however suffers from the low W/Cu bonding strength due to the immiscible nature of W-Cu system. In this study, we proposed a method for strengthened W/Cu joining based on femtosecond (fs) laser induced micron-scale W/Cu interface structure. W surfaces were irradiated by fs laser to form micron-scale cubes array, and then joined to Cu by hot pressing at 1000 °C, 80 MPa for 2.5 hours. The tensile strength of the W/Cu joining samples was investigated. The results show that micron-scale cubes array was successfully introduced into W/Cu interface without any cracks or pores. The interface structure helps to increase the W/Cu bonding strength to as high as 59.61 MPa, increased by about 50% as compared to W/Cu joining with a flat interface (bonding strength 40.11 MPa). The W/Cu bonding strength shows positive correlation with the W/Cu interface area, indicating the possibility to control the W/Cu bonding strength by simply adjusting the fs laser ablation parameters for the fabrication of cubes array on W surface. Our research provides a method for strengthened joining between intrinsically immiscible materials, including but not limited to W and Cu.

  5. Joining and Assembly of Silicon Carbide-based Advanced Ceramics and Composites for High Temperature Applications

    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.

  6. Robust Joining and Integration of Advanced Ceramics and Composites: Challenges, Opportunities, and Realities

    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.

  7. Joining and Attachment Technologies for Ceramic Matrix Composites: Current Status and Future Prospects

    NASA Technical Reports Server (NTRS)

    Singh, M.

    2002-01-01

    Fiber reinforced ceramic composites are either currently being used, or are under active consideration for use in a wide variety of high temperature applications. 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 aerospace and ground based applications. In this presentation, various challenges and opportunities in design, fabrication, and testing of high temperature joints in 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 (C/C, C/SiC, and SiC), 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.

  8. Durability of amide N-chloramine biocides to ethylene oxide sterilization.

    PubMed

    Zhao, Nan; Logsetty, Sarvesh; Liu, Song

    2012-01-01

    The objective of this work is to study the stability of three novel topical antimicrobial dressings consisting of amide N-chloramine structures against ethylene oxide sterilization. Cotton gauze samples bonded with one of three amide N-chloramine structures were subjected to standard ethylene oxide (EtO) sterilization. The amounts of amide N-chloramine structures before and after the sterilization were quantified to indicate the stabilities of these amide N-chloramine structures to the sterilization. The samples after sterilization were challenged with a clinical isolate of healthcare-associated multidrug-resistant Escherichia coli. N-Chloramine structure converted from polymethacrylamide (dressing 2) had the highest durability (89.7% retained active chlorine) toward EtO sterilization; that from hydantoin (dressing 3; 86.3% retained active chlorine) followed; and poly(N-chloroacrylamide) (dressing 1) had the lowest (64.0% retained active chlorine). After EtO sterilization, all the samples still reduced E. coli presence at 5 minutes of contact, with dressing 2 retaining a log 6 reduction. The three tested amide N-chloramine structures could all survive EtO sterilization while retaining percentages of active chlorine ranging from 64.0 to 89.7%. Dressing 2 showed the best durability, whereas dressing 1 had the poorest durability. With the remaining amounts of amide N-chloramine structures after EtO sterilization, all the dressings could still reduce E. coli numbers within 5 minutes of contact, and dressing 2 resulted in a log 6 reduction in colony count.

  9. Amide I vibrational circular dichroism of dipeptide: Conformation dependence and fragment analysis

    NASA Astrophysics Data System (ADS)

    Choi, Jun-Ho; Cho, Minhaeng

    2004-03-01

    The amide I vibrational circular dichroic response of alanine dipeptide analog (ADA) was theoretically investigated and the density functional theory calculation and fragment analysis results are presented. A variety of vibrational spectroscopic properties, local and normal mode frequencies, coupling constant, dipole, and rotational strengths, are calculated by varying two dihedral angles determining the three-dimensional ADA conformation. Considering two monopeptide fragments separately, we show that the amide I vibrational circular dichroism of the ADA can be quantitatively predicted. For several representative conformations of the model ADA, vibrational circular dichroism spectra are calculated by using both the density functional theory calculation and fragment analysis methods.

  10. Diastereoselective and enantioselective conjugate addition reactions utilizing α,β-unsaturated amides and lactams.

    PubMed

    Byrd, Katherine M

    2015-01-01

    The conjugate addition reaction has been a useful tool in the formation of carbon-carbon bonds. The utility of this reaction has been demonstrated in the synthesis of many natural products, materials, and pharmacological agents. In the last three decades, there has been a significant increase in the development of asymmetric variants of this reaction. Unfortunately, conjugate addition reactions using α,β-unsaturated amides and lactams remain underdeveloped due to their inherently low reactivity. This review highlights the work that has been done on both diastereoselective and enantioselective conjugate addition reactions utilizing α,β-unsaturated amides and lactams.

  11. Aryl Piperazinyl Ureas as Inhibitors of Fatty Acid Amide Hydrolase (FAAH) in Rat, Dog, and Primate.

    PubMed

    Keith, John M; Apodaca, Rich; Tichenor, Mark; Xiao, Wei; Jones, William; Pierce, Joan; Seierstad, Mark; Palmer, James; Webb, Michael; Karbarz, Mark; Scott, Brian; Wilson, Sandy; Luo, Lin; Wennerholm, Michelle; Chang, Leon; Brown, Sean; Rizzolio, Michele; Rynberg, Raymond; Chaplan, Sandra; Breitenbucher, J Guy

    2012-10-11

    A series of aryl piperazinyl ureas that act as covalent inhibitors of fatty acid amide hydrolase (FAAH) is described. A potent and selective (does not inhibit FAAH-2) member of this class, JNJ-40355003, was found to elevate the plasma levels of three fatty acid amides: anandamide, oleoyl ethanolamide, and palmitoyl ethanolamide, in the rat, dog, and cynomolgous monkey. The elevation of the levels of these lipids in the plasma of monkeys suggests that FAAH-2 may not play a significant role in regulating plasma levels of fatty acid ethanolamides in primates.

  12. Amide functionalized MWNT/SPEEK composite membrane for better electrochemical performance

    NASA Astrophysics Data System (ADS)

    Gahlot, Swati; Sharma, Prem P.; Kulshrestha, Vaibhav

    2016-05-01

    Nanocomposite membranes based on multiwalled carbon nanotube /SPEEK (sulfonated poly ether ether ketone) have been synthesized via simple solution casting. Prior to use CNT have been purified and grafted with carboxylic acid groups onto its walls by means of sulfuric and nitric acid. Afterwards, amidation of carboxylated CNTs (c-CNT) has been done. Amidated CNT (a-CNT) is then incorporated in SPEEK polymer matrix to synthesize nanocomposite membranes. Physicochemical, structural, thermal and mechanical characterizations are done through the respective techniques. Electric and ionic conductivities have also been evaluated. Composites membranes show the enhanced electrochemical performance with higher electric conductivity.

  13. Diastereoselective and enantioselective conjugate addition reactions utilizing α,β-unsaturated amides and lactams

    PubMed Central

    2015-01-01

    Summary The conjugate addition reaction has been a useful tool in the formation of carbon–carbon bonds. The utility of this reaction has been demonstrated in the synthesis of many natural products, materials, and pharmacological agents. In the last three decades, there has been a significant increase in the development of asymmetric variants of this reaction. Unfortunately, conjugate addition reactions using α,β-unsaturated amides and lactams remain underdeveloped due to their inherently low reactivity. This review highlights the work that has been done on both diastereoselective and enantioselective conjugate addition reactions utilizing α,β-unsaturated amides and lactams. PMID:25977728

  14. Synthesis of β-Glycosyl Amides from N-Glycosyl Dinitrobenzenesulfonamides.

    PubMed

    Gaitonde, Vishwanath; Sucheck, Steven J

    2012-01-01

    The N-glycosyl-2,4-dinitrobenzenesulfonamides were accessed via benzoyl-protected β-glycosyl azides. The azides were reduced with Adams' catalyst to the corresponding amines. The glycosylamines were sulfonated with 2,4-dinitrobenzenesulfonyl chloride to form N-glycosyl-2,4-dinitrobenzenesulfonamides in moderate yields. β-Glycosyl amides were then prepared in 67 - 81 % yields by treatment of the sulfonamides with thioacetic acid and cesium carbonate. The conversion of the glycosylsulfonamide to the glycosyl amide proceeded with high stereoselectivity.

  15. Synthesis of β-Glycosyl Amides from N-Glycosyl Dinitrobenzenesulfonamides

    PubMed Central

    Gaitonde, Vishwanath; Sucheck, Steven J.

    2013-01-01

    The N-glycosyl-2,4-dinitrobenzenesulfonamides were accessed via benzoyl-protected β-glycosyl azides. The azides were reduced with Adams’ catalyst to the corresponding amines. The glycosylamines were sulfonated with 2,4-dinitrobenzenesulfonyl chloride to form N-glycosyl-2,4-dinitrobenzenesulfonamides in moderate yields. β-Glycosyl amides were then prepared in 67 – 81 % yields by treatment of the sulfonamides with thioacetic acid and cesium carbonate. The conversion of the glycosylsulfonamide to the glycosyl amide proceeded with high stereoselectivity. PMID:23349564

  16. Naphthalene/quinoline amides and sulfonylureas as potent and selective antagonists of the EP4 receptor.

    PubMed

    Burch, Jason D; Farand, Julie; Colucci, John; Sturino, Claudio; Ducharme, Yves; Friesen, Richard W; Lévesque, Jean-François; Gagné, Sébastien; Wrona, Mark; Therien, Alex G; Mathieu, Marie-Claude; Denis, Danielle; Vigneault, Erika; Xu, Daigen; Clark, Patsy; Rowland, Steve; Han, Yongxin

    2011-02-01

    Two new series of EP(4) antagonists based on naphthalene/quinoline scaffolds have been identified as part of our on-going efforts to develop treatments for inflammatory pain. One series contains an acidic sulfonylurea pharmacophore, whereas the other is a neutral amide. Both series show subnanomolar intrinsic binding potency towards the EP(4) receptor, and excellent selectivity towards other prostanoid receptors. While the amide series generally displays poor pharmacokinetic parameters, the sulfonylureas exhibit greatly improved profile. MF-592, the optimal compound from the sulfonylurea series, has a desirable overall preclinical profile that suggests it is suitable for further development.

  17. Synthesis, properties and applications of biodegradable polymers derived from diols and dicarboxylic acids: from polyesters to poly(ester amide)s.

    PubMed

    Díaz, Angélica; Katsarava, Ramaz; Puiggalí, Jordi

    2014-04-25

    Poly(alkylene dicarboxylate)s constitute a family of biodegradable polymers with increasing interest for both commodity and speciality applications. Most of these polymers can be prepared from biobased diols and dicarboxylic acids such as 1,4-butanediol, succinic acid and carbohydrates. This review provides a current status report concerning synthesis, biodegradation and applications of a series of polymers that cover a wide range of properties, namely, materials from elastomeric to rigid characteristics that are suitable for applications such as hydrogels, soft tissue engineering, drug delivery systems and liquid crystals. Finally, the incorporation of aromatic units and α-amino acids is considered since stiffness of molecular chains and intermolecular interactions can be drastically changed. In fact, poly(ester amide)s derived from naturally occurring amino acids offer great possibilities as biodegradable materials for biomedical applications which are also extensively discussed.

  18. Synthesis, Properties and Applications of Biodegradable Polymers Derived from Diols and Dicarboxylic Acids: From Polyesters to Poly(ester amide)s

    PubMed Central

    Díaz, Angélica; Katsarava, Ramaz; Puiggalí, Jordi

    2014-01-01

    Poly(alkylene dicarboxylate)s constitute a family of biodegradable polymers with increasing interest for both commodity and speciality applications. Most of these polymers can be prepared from biobased diols and dicarboxylic acids such as 1,4-butanediol, succinic acid and carbohydrates. This review provides a current status report concerning synthesis, biodegradation and applications of a series of polymers that cover a wide range of properties, namely, materials from elastomeric to rigid characteristics that are suitable for applications such as hydrogels, soft tissue engineering, drug delivery systems and liquid crystals. Finally, the incorporation of aromatic units and α-amino acids is considered since stiffness of molecular chains and intermolecular interactions can be drastically changed. In fact, poly(ester amide)s derived from naturally occurring amino acids offer great possibilities as biodegradable materials for biomedical applications which are also extensively discussed. PMID:24776758

  19. A Novel Amidase (Half-Amidase) for Half-Amide Hydrolysis Involved in the Bacterial Metabolism of Cyclic Imides

    PubMed Central

    Soong, Chee-Leong; Ogawa, Jun; Shimizu, Sakayu

    2000-01-01

    A novel amidase involved in bacterial cyclic imide metabolism was purified from Blastobacter sp. strain A17p-4. The enzyme physiologically functions in the second step of cyclic imide degradation, i.e., the hydrolysis of monoamidated dicarboxylates (half-amides) to dicarboxylates and ammonia. Enzyme production was enhanced by cyclic imides such as succinimide and glutarimide but not by amide compounds which are conventional substrates and inducers of known amidases. The purified amidase showed high catalytic efficiency toward half-amides such as succinamic acid (Km = 6.2 mM; kcat = 5.76 s−1) and glutaramic acid (Km = 2.8 mM; kcat = 2.23 s−1). However, the substrates of known amidases such as short-chain (C2 to C4) aliphatic amides, long-chain (above C16) aliphatic amides, amino acid amides, aliphatic diamides, α-keto acid amides, N-carbamoyl amino acids, and aliphatic ureides were not substrates for the enzyme. Based on its high specificity toward half-amides, the enzyme was named half-amidase. This half-amidase exists as a monomer with an Mr of 48,000 and was strongly inhibited by heavy metal ions and sulfhydryl reagents. PMID:10788365

  20. A convenient synthesis of anthranilic acids by Pd-catalyzed direct intermolecular ortho-C-H amidation of benzoic acids.

    PubMed

    Ng, Ka-Ho; Ng, Fo-Ning; Yu, Wing-Yiu

    2012-12-11

    An efficient method for synthesis of anthranilic acids by Pd-catalyzed ortho-C-H amidation of benzoic acids is disclosed. The amidation is proposed to proceed by carboxylate-assisted ortho-C-H palladation to form an arylpalladium(II) complex, followed by nitrene insertion to the Pd-C bond.