WorldWideScience

Sample records for carbonyl-promoted c-s bond

  1. On the Mechanism of the Copper-Mediated C-S Bond Formation in the Intramolecular Disproportionation of Imine Disulfides

    Czech Academy of Sciences Publication Activity Database

    Rokob, Tibor András; Rulíšek, Lubomír; Šrogl, Jiří; Révész, Agnes; Zins, Emilie-Laure; Schröder, Detlef

    2011-01-01

    Roč. 50, č. 20 (2011), s. 9968-9979 ISSN 0020-1669 R&D Projects: GA MŠk LC512 Grant - others:European Research Council(XE) AdG HORIZOMS Institutional research plan: CEZ:AV0Z40550506 Keywords : collision-induced dissociation * DFT calculations * C-S bond formation * Cu(I) catalysis * infrared multiphoton spectroscopy Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 4.601, year: 2011

  2. Microwave-assisted Ullmann C-S bond formation: synthesis of the P38alpha MAPK clinical candidate VX-745.

    Science.gov (United States)

    Bagley, Mark C; Davis, Terence; Dix, Matthew C; Fusillo, Vincenzo; Pigeaux, Morgane; Rokicki, Michal J; Kipling, David

    2009-11-06

    Microwave irradiation promotes the rapid and efficient reaction of a thiophenol and aryl or heteroaryl halide using a copper or palladium catalyst and a range of ligands, depending upon substrate. Of particular utility is the use of copper(I) iodide (5 mol %) and trans-cyclohexane-1,2-diol as ligand under basic conditions and microwave irradiation to give the corresponding sulfide in high yield. This method for C-S bond formation is applied in the four-step synthesis of the clinical candidate VX-745 in 38% overall yield. The inhibitory activity of VX-745 against p38alpha MAPK is confirmed in Werner syndrome dermal fibroblasts at 1.0 microM concentration by immunoblot assay.

  3. Copper-Catalyzed Oxidative Reaction of β-Keto Sulfones with Alcohols via C-S Bond Cleavage: Reaction Development and Mechanism Study.

    Science.gov (United States)

    Du, Bingnan; Wang, Wenmin; Wang, Yang; Qi, Zhenghang; Tian, Jiaqi; Zhou, Jie; Wang, Xiaochen; Han, Jianlin; Ma, Jing; Pan, Yi

    2018-02-16

    A Cu-catalyzed cascade oxidative radical process of β-keto sulfones with alcohols has been achieved by using oxygen as an oxidant. In this reaction, β-keto sulfones were converted into sulfinate esters under the oxidative conditions via cleavage of C-S bond. Experimental and computational studies demonstrate that a new pathway is involved in this reaction, which proceeds through the formation of the key four-coordinated Cu II intermediate, O-O bond homolysis induced C-S bond cleavage and Cu-catalyzed esterification to form the final products. This reaction provides a new strategy to sulfonate esters and enriches the research content of C-S bond cleavage and transformations. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Multiple C-H Bond Activations and Ring-Opening C-S Bond Cleavage of Thiophene by Dirhenium Carbonyl Complexes.

    Science.gov (United States)

    Adams, Richard D; Dhull, Poonam; Tedder, Jonathan D

    2018-06-14

    The reaction of Re 2 (CO) 8 (μ-C 6 H 5 )(μ-H) (1) with thiophene in CH 2 Cl 2 at 40 °C yielded the new compound Re 2 (CO) 8 (μ-η 2 -SC 4 H 3 )(μ-H) (2), which contains a bridging σ-π-coordinated thienyl ligand formed by the activation of the C-H bond at the 2 position of the thiophene. Compound 2 exhibits dynamical activity on the NMR time scale involving rearrangements of the bridging thienyl ligand. The reaction of compound 2 with a second 1 equiv of 1 at 45 °C yielded the doubly metalated product [Re 2 (CO) 8 (μ-H)] 2 (μ-η 2 -2,3-μ-η 2 -4,5-C 4 H 2 S) (3), formed by the activation of the C-H bond at the 5 position of the thienyl ligand in 2. Heating 3 in a hexane solvent to reflux transformed it into the ring-opened compound Re(CO) 4 [μ-η 5 -η 2 -SCC(H)C(H)C(H)][Re(CO) 3 ][Re 2 (CO) 8 (μ-H)] (4) by the loss of one CO ligand. Compound 4 contains a doubly metalated 1-thiapentadienyl ligand formed by the cleavage of one of the C-S bonds. When heated to reflux (125 °C) in an octane solvent in the presence of H 2 O, the new compound Re(CO) 4 [η 5 -μ-η 2 -SC(H)C(H)C(H)C(H)]Re(CO) 3 (5) was obtained by cleavage of the Re 2 (CO) 8 (μ-H) group from 4 with formation of the known coproduct [Re(CO) 3 (μ 3 -OH)] 4 . All new products were characterized by single-crystal X-ray diffraction analyses.

  5. Synthesis of 1,2,4-Triazoles via Oxidative Heterocyclization: Selective C-N Bond Over C-S Bond Formation.

    Science.gov (United States)

    Gogoi, Anupal; Guin, Srimanta; Rajamanickam, Suresh; Rout, Saroj Kumar; Patel, Bhisma K

    2015-09-18

    The higher propensity of C-N over C-S bond forming ability was demonstrated, through formal C-H functionalization during the construction of 4,5-disubstituted 1,2,4-triazole-3-thiones from arylidenearylthiosemicarbazides catalyzed by Cu(II). However, steric factors imparted by the o-disubstituted substrates tend to change the reaction path giving thiodiazole as the major or an exclusive product. Upon prolonging the reaction time, the in situ generated thiones are transformed to 4,5-disubstituted 1,2,4-triazoles via a desulfurization process. Two classes of heterocycles viz. 4,5-disubstituted 1,2,4-triazole-3-thiones and 4,5-disubstituted 1,2,4-triazoles can be synthesized from arylidenearylthiosemicarbazides by simply adjusting the reaction time. Desulfurization of 1,2,4-triazole-3-thiones is assisted by thiophilic Cu to provide 1,2,4-triazoles with concomitant formation of CuS and polynuclear sulfur anions as confirmed from scanning electron microscope and energy dispersive X-ray spectroscopy measurements. A one-pot synthesis of an antimicrobial compound has been successfully achieved following this strategy.

  6. Hydrodesulfurization on Transition Metal Catalysts: Elementary Steps of C-S Bond Activation and Consequences of Bifunctional Synergies

    Science.gov (United States)

    Yik, Edwin Shyn-Lo

    convergence to a single phase is expected and predictable from thermodynamics at a given temperature and sulfur chemical potential, metastability of two phases can exist. We demonstrate, through extensive characterization and kinetic evidence, such behaviors exist in Re, where structural disparities between its phases lead to kinetic hurdles that prevent interconversions between layered ReSx nanostructures and sulfur-covered Re metal clusters. Such features allowed, for the first time, direct comparisons of reaction rates at identical conditions on two disparate phases of the same transition metal identity. Rigorous assessments of kinetic and selectivity data indicated that more universal mechanistic features persist across all catalysts studied, suggesting that differences in their catalytic activity were the result of different densities of HDS sites, which appeared to correlate with their respective metal-sulfur bond energies. Kinetic responses and product distributions indicated that the consumption of thiophene proceeds by the formation of a partially-hydrogenated surface intermediate, which subsequently produces tetrahydrothiophene (THT) and butene/butane (C4) via primary routes on similar types of sites. These sites are formed from desorption of weakly-bound sulfur adatoms on sulfur-covered metal surfaces, which can occur when the heat of sulfur adsorption is sufficiently low at high sulfur coverage as a result of increased sulfur-sulfur repulsive interactions. Relative stabilities and differences in the molecularity of the respective transition states that form THT and C4 dictate product distributions. THT desulfurization to form C4 occurs via readsorption and subsequent dehydrogenation, evidenced by secondary rates that exhibited negative H2 dependences. These behaviors suggest that C-S bond activation occurs on a partially (un)saturated intermediate, analogous to behaviors observed in C-C bond scission reactions of linear and cycloalkanes on hydrogen-covered metal

  7. Nickel-Catalyzed C-S Bond Formation via Decarbonylative Thioetherification of Esters, Amides and Intramolecular Recombination Fragment Coupling of Thioesters

    KAUST Repository

    Lee, Shao-Chi

    2018-01-15

    A nickel catalyzed cross-coupling protocol for the straightforward C-S bond formation has been developed. Various mercaptans and a wide range of ester and amide substrates bearing various substituents were tolerated in this process which afforded products in good to excellent yields. Furthermore, an intramolecular protocol for the synthesis of thioethers starting from thioesters has been developed. The utility of this protocol has been demonstrated in the synthesis of benzothiophene on the bench top.

  8. Nickel-Catalyzed C-S Bond Formation via Decarbonylative Thioetherification of Esters, Amides and Intramolecular Recombination Fragment Coupling of Thioesters

    KAUST Repository

    Lee, Shao-Chi; Liao, Hsuan-Hung; Chatupheeraphat, Adisak; Rueping, Magnus

    2018-01-01

    A nickel catalyzed cross-coupling protocol for the straightforward C-S bond formation has been developed. Various mercaptans and a wide range of ester and amide substrates bearing various substituents were tolerated in this process which afforded products in good to excellent yields. Furthermore, an intramolecular protocol for the synthesis of thioethers starting from thioesters has been developed. The utility of this protocol has been demonstrated in the synthesis of benzothiophene on the bench top.

  9. Studies toward the oxidative and reductive activation of C-S bonds in 2'-S-aryl-2'-thiouridine derivatives.

    Science.gov (United States)

    Rayala, Ramanjaneyulu; Giuglio-Tonolo, Alain; Broggi, Julie; Terme, Thierry; Vanelle, Patrice; Theard, Patricia; Médebielle, Maurice; Wnuk, Stanislaw F

    2016-04-21

    Studies directed toward the oxidative and reductive desulfurization of readily available 2'- S -aryl-2'-thiouridine derivatives were investigated with the prospect to functionalize the C2'-position of nucleosides. The oxidative desulfurization-difluorination strategy was successful on 2-(arylthio)alkanoate surrogates, while extension of the combination of oxidants and fluoride sources was not an efficient fluorination protocol when applied to 2'- S -aryl-2'-thiouridine derivatives, resulting mainly in C5-halogenation of the pyrimidine ring and C2'-monofluorination without desulfurization. Cyclic voltammetry of 2'-arylsulfonyl-2'-deoxyuridines and their 2'-fluorinated analogues showed that cleavage of the arylsulfone moiety could occur, although at relatively high cathodic potentials. While reductive-desulfonylation of 2'-arylsulfonyl-2'-deoxyuridines with organic electron donors (OEDs) gave predominantly base-induced furan type products, chemical (OED) and electrochemical reductive-desulfonylation of the α-fluorosulfone derivatives yielded the 2'-deoxy-2'-fluorouridine and 2',3'-didehydro-2',3'-dideoxy-2'-fluorouridine derivatives. These results provided good evidence of the generation of a C2'-anion through carbon-sulfur bond cleavage, opening new horizons for the reductive-functionalization approaches in nucleosides.

  10. Studies toward the oxidative and reductive activation of C-S bonds in 2'-S-aryl-2'-thiouridine derivatives

    Science.gov (United States)

    Rayala, Ramanjaneyulu; Giuglio-Tonolo, Alain; Broggi, Julie; Terme, Thierry; Vanelle, Patrice; Theard, Patricia; Médebielle, Maurice; Wnuk, Stanislaw F.

    2016-01-01

    Studies directed toward the oxidative and reductive desulfurization of readily available 2'-S-aryl-2'-thiouridine derivatives were investigated with the prospect to functionalize the C2'-position of nucleosides. The oxidative desulfurization-difluorination strategy was successful on 2-(arylthio)alkanoate surrogates, while extension of the combination of oxidants and fluoride sources was not an efficient fluorination protocol when applied to 2'-S-aryl-2'-thiouridine derivatives, resulting mainly in C5-halogenation of the pyrimidine ring and C2'-monofluorination without desulfurization. Cyclic voltammetry of 2'-arylsulfonyl-2'-deoxyuridines and their 2'-fluorinated analogues showed that cleavage of the arylsulfone moiety could occur, although at relatively high cathodic potentials. While reductive-desulfonylation of 2'-arylsulfonyl-2'-deoxyuridines with organic electron donors (OEDs) gave predominantly base-induced furan type products, chemical (OED) and electrochemical reductive-desulfonylation of the α-fluorosulfone derivatives yielded the 2'-deoxy-2'-fluorouridine and 2',3'-didehydro-2',3'-dideoxy-2'-fluorouridine derivatives. These results provided good evidence of the generation of a C2'-anion through carbon-sulfur bond cleavage, opening new horizons for the reductive-functionalization approaches in nucleosides. PMID:27019535

  11. Synthesis of Bioactive 2-(Arylaminothiazolo[5,4-f]-quinazolin-9-ones via the Hügershoff Reaction or Cu- Catalyzed Intramolecular C-S Bond Formation

    Directory of Open Access Journals (Sweden)

    Damien Hédou

    2016-06-01

    Full Text Available A library of thirty eight novel thiazolo[5,4-f]quinazolin-9(8H-one derivatives (series 8, 10, 14 and 17 was prepared via the Hügershoff reaction and a Cu catalyzed intramolecular C-S bond formation, helped by microwave-assisted technology when required. The efficient multistep synthesis of the key 6-amino-3-cyclopropylquinazolin-4(3H-one (3 has been reinvestigated and performed on a multigram scale from the starting 5-nitroanthranilic acid. The inhibitory potency of the final products was evaluated against five kinases involved in Alzheimer’s disease and showed that some molecules of the 17 series described in this paper are particularly promising for the development of novel multi-target inhibitors of kinases.

  12. Recognition of a novel type X═N-Hal···Hal (X = C, S, P; Hal = F, Cl, Br, I) halogen bonding.

    Science.gov (United States)

    Gushchin, Pavel V; Kuznetsov, Maxim L; Haukka, Matti; Kukushkin, Vadim Yu

    2013-04-04

    The chlorination of the eight-membered platinum(II) chelates [PtCl2{NH═C(NR2)N(Ph)C(═NH)N(Ph)C(NR2)═NH}] (R = Me (1); R2 = (CH2)5 (2)) with uncomplexed imino group with Cl2 gives complexes bearing the ═N-Cl moiety [PtCl4{NH═C(NR2)N(Ph)C(═NCl)N(Ph)C(NR2)═NH}] (R = Me (3); R2 = (CH2)5 (4)). X-ray study for 3 revealed a novel type intermolecular halogen bonding ═N-Cl···Cl(-), formed between the Cl atom of the chlorinated imine and the chloride bound to the platinum(IV) center. The processing relevant structural data retrieved from the Cambridge Structural Database (CSDB) shows that this type of halogen bonding is realized in 18 more molecular species having X═N-Hal moieties (X = C, P, S, V, W; Hal = Cl, Br, I), but this weak ═N-Hal···Hal(-) bonding was totally neglected in the previous works. The presence of the halogen bonding in 3 was confirmed by theoretical calculations at the density functional theory (DFT, M06-2X) level, and its nature was analyzed.

  13. L C S Murthy

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. L C S Murthy. Articles written in Bulletin of Materials Science. Volume 27 Issue 3 June 2004 pp 295-301 Thin Films. Studies on tin oxide films prepared by electron beam evaporation and spray pyrolysis methods · K S Shamala L C S Murthy K Narasimha Rao · More Details ...

  14. C S Smith

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education. C S Smith. Articles written in Resonance – Journal of Science Education. Volume 11 Issue 6 June 2006 pp 79-93 Classics. Excerpts from A Search for Structure · C S Smith · More Details Fulltext PDF ...

  15. C S Sanmathi

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science. C S Sanmathi. Articles written in Bulletin of Materials Science. Volume 27 Issue 3 June 2004 pp 243-249 Polymers. Terpolymerization of 2-ethoxy ethylmethacrylate, styrene and maleic anhydride: determination of the reactivity ratios · C S Sanmathi S Prasannakumar B S ...

  16. Umesh C S Yadav

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Biosciences. Umesh C S Yadav. Articles written in Journal of Biosciences. Volume 28 Issue 2 March 2003 pp 215-221 Articles. Regulation of glucose utilization and lipogenesis in adipose tissue of diabetic and fat fed animals: Effects of insulin and manganese · Najma Z Baquer M Sinclair S ...

  17. C. S. Lewis: The Romantic Rationalist

    Directory of Open Access Journals (Sweden)

    Vasiliu Daniela

    2014-12-01

    Full Text Available The paper “C. S. Lewis: The Romantic Rationalist” presents the way C. S. Lewis gives an account in his first fictional (allegorical book, The Pilgrim’s Regress, of how he discovered Christianity on the converging paths of romanticism and rationalism. The outstanding scholar and author whose intellectual and spiritual development has turned him into one of the most influential Christian writers of the twentieth century became an atheist in his teens and after a long journey through different philosophical convictions he converted to Christianity in his early thirties, a change that affected his entire work. His love of literature was essential in discovering both the rational and the imaginative appeal of Christianity, which led him into a vision of the reality of the world and of life that satisfied the longing of his heart and the hunger of his imagination.

  18. Calorimetric studies on ZrC(s)

    International Nuclear Information System (INIS)

    Banerjee, Aparna; Venugopal, V.

    1998-01-01

    Enthalpy increments of ZrC(s) were determined using a Calvet micro-calorimeter in the temperature range 349.5 to 664.0 K. The enthalpy increment values were least squares analysed using the SHOMATE programme and the best fit is represented by the following polynomial equation: H o (T)-H o (298.15 K)(J/mol) = 48.44 T(K) + 0.375x10 -2 T 2 (K) + 11.67x10 5 /T(K) - 18691.97. Molar heat capacity and other thermal properties have been evaluated. (author)

  19. A concise, efficient synthesis of sugar-based benzothiazoles through chemoselective intramolecular C-S coupling

    KAUST Repository

    Shen, Chao

    2012-01-01

    Sugar-based benzothiazoles are a new class of molecules promising for many biological applications. Here, we have synthesized a wide range of sugar-based benzothiazoles from readily accessible glycosyl thioureas by chemoselective, palladium-catalyzed C-S coupling reactions. Corroborated by theoretical calculations, a mechanistic investigation indicates that the coordination to the palladium by a pivaloyl carbonyl group and the presence of intramolecular hydrogen bonding play important roles in the efficiency and chemoselectivity of reaction. These fluorescent glycoconjugates can be observed to readily enter mammalian tumor cells and exhibit potential in vitro antitumor activity. This journal is © The Royal Society of Chemistry 2012.

  20. Bond Issues.

    Science.gov (United States)

    Pollack, Rachel H.

    2000-01-01

    Notes trends toward increased borrowing by colleges and universities and offers guidelines for institutions that are considering issuing bonds to raise money for capital projects. Discussion covers advantages of using bond financing, how use of bonds impacts on traditional fund raising, other cautions and concerns, and some troubling aspects of…

  1. Parental Bonding

    Directory of Open Access Journals (Sweden)

    T. Paul de Cock

    2014-08-01

    Full Text Available Estimating the early parent–child bonding relationship can be valuable in research and practice. Retrospective dimensional measures of parental bonding provide a means for assessing the experience of the early parent–child relationship. However, combinations of dimensional scores may provide information that is not readily captured with a dimensional approach. This study was designed to assess the presence of homogeneous groups in the population with similar profiles on parental bonding dimensions. Using a short version of the Parental Bonding Instrument (PBI, three parental bonding dimensions (care, authoritarianism, and overprotection were used to assess the presence of unobserved groups in the population using latent profile analysis. The class solutions were regressed on 23 covariates (demographics, parental psychopathology, loss events, and childhood contextual factors to assess the validity of the class solution. The results indicated four distinct profiles of parental bonding for fathers as well as mothers. Parental bonding profiles were significantly associated with a broad range of covariates. This person-centered approach to parental bonding has broad utility in future research which takes into account the effect of parent–child bonding, especially with regard to “affectionless control” style parenting.

  2. C&S Enterprise, L.L.C.

    Science.gov (United States)

    The EPA is providing notice of a proposed Administrative Penalty Assessment against C & S Enterprise, L.L.C. (“Respondent”), a business located at 2454 480th Ave, Deep River, IA 52222, for alleged violations of the Clean Water Act at property owned by Resp

  3. C. S. Lewis, Reluctant Convert and (not so Ordinary Anglican

    Directory of Open Access Journals (Sweden)

    Mănăstireanu Dănuţ

    2014-12-01

    Full Text Available After some passing considerations on the reception of Lewis in Romania, the present paper discusses the role played by Anglicanism in the late personal commitment of C.S. Lewis to the Christian faith, after years of atheism, scepticism, and agnosticism. It argues that in fact Anglicanism contributed very little to Lewis’s (reconversion to Christianity. Furthermore, the paper agrees with the generally accepted idea that the particular calling that Lewis felt he had, that of being a Christian apologist, made him wary of being associated with the defence of any specific Christian tradition. In virtue of this special calling, Lewis also reacted quite strongly against certain aspects of Anglicanism, like, for instance, the ordination of women to priesthood, which he perceived as an obstacle to ecumenism and, implicitly, to an effective defence of the Christian faith in the public arena. In spite of all this, there is little doubt that Lewis has fully and unreservedly adopted Anglicanism as his preferred version of Christianity. From this particular stance, the life and ministry of C.S. Lewis made a huge public impact in the twentieth century and beyond. In light of the undeniable influence he had on the intellectual and religious scene in the last hundred years, one may ask not so much how Anglican was Lewis, but, rather, ‘why isn’t Anglicanism more like Lewis’.

  4. Bonds Boom.

    Science.gov (United States)

    Reynolds, Cathryn

    1989-01-01

    The combined effect of the "Serrano" decision and Proposition 13 left California school districts with aging, overcrowded facilities. Chico schools won a $18.5 million general obligation bond election for facilities construction. With $11 billion needed for new school construction, California will need to tap local sources. A sidebar…

  5. Diffusion bonding

    International Nuclear Information System (INIS)

    Anderson, R.C.

    1976-01-01

    A method is described for joining beryllium to beryllium by diffusion bonding. At least one surface portion of at least two beryllium pieces is coated with nickel. A coated surface portion is positioned in a contiguous relationship with another surface portion and subjected to an environment having an atmosphere at a pressure lower than ambient pressure. A force is applied on the beryllium pieces for causing the contiguous surface portions to abut against each other. The contiguous surface portions are heated to a maximum temperature less than the melting temperature of the beryllium, and the applied force is decreased while increasing the temperature after attaining a temperature substantially above room temperature. A portion of the applied force is maintained at a temperature corresponding to about maximum temperature for a duration sufficient to effect the diffusion bond between the contiguous surface portions

  6. FCA containment and surveillance (C/S) system

    International Nuclear Information System (INIS)

    Ogawa, Hironobu; Mukaiyama, Takehiko; Yokota, Yasuhiro.

    1994-11-01

    The Fast Critical Assembly (FCA) facility of the Japan Atomic Energy Research Inst. (JAERI) is internationally recognized as one of the most sensitive facility in the world from the viewpoint of international safeguards, because the facility possesses a large amount of metallic uranium and metallic plutonium, which are needed to perform various physical experiments. These material are subject to frequent verifications by the inspectorate, the International Atomic Energy Agency (IAEA) and the domestic authority (Science and Technology Agency of Japan, STA). Those verifications require inspectors to access to these materials for measurements and applications of seals. Human resources increase of irradiations and restrictions on the freedom of physical experiments, that are inevitably associated with these inspection activities, have been a serious problem that causes significant burdens for all relating parties. To decrease these burdens without any confliction with the inspection goals, an advanced comprehensive system of containment and surveillance has been developed. The FCA Containment and Surveillance (C/S) System consists of tow independent subsystems, i. e. Portal Monitor (P/M) and Penetration Monitor(PN/M). In this system the internal wall of the reactor building is used as a part of containment for the safeguards purpose, which enables the portal, that is installed at the internal wall of the reactor building, to be used as an area for monitoring of any removal of nuclear material. A metal detector of high sensitivity has been selected for the system since all nuclear materials possessed by the FCA has metallic forms. The internal wall has several penetrations for utility purposes, which should also be monitored for the purpose of detecting any removal of nuclear material from the reactor core area. A penetration monitor system has been developed for this purpose. This report describes functions of the system and their operation procedures. (author)

  7. Structure and bonding in clusters

    International Nuclear Information System (INIS)

    Kumar, V.

    1991-10-01

    We review here the recent progress made in the understanding of the electronic and atomic structure of small clusters of s-p bonded materials using the density functional molecular dynamics technique within the local density approximation. Starting with a brief description of the method, results are presented for alkali metal clusters, clusters of divalent metals such as Mg and Be which show a transition from van der Waals or weak chemical bonding to metallic behaviour as the cluster size grows and clusters of Al, Sn and Sb. In the case of semiconductors, we discuss results for Si, Ge and GaAs clusters. Clusters of other materials such as P, C, S, and Se are also briefly discussed. From these and other available results we suggest the possibility of unique structures for the magic clusters. (author). 69 refs, 7 figs, 1 tab

  8. Fe-C-S systematics in Bengal Fan sediments

    Science.gov (United States)

    Volvoikar, S. P.; Mazumdar, A.; Goswami, H.; Pujari, S.; Peketi, A.

    2017-12-01

    Global biogeochemical cycles of iron, carbon and sulfur (Fe-C-S) are interrelated. Sulfate reduction in marine sediments is the major factor controlling the cycling and burial of carbon, sulfur and iron. Organoclastic sulfate reduction and anaerobic oxidation of methane (AOM) are the two main processes responsible for sulfate reduction in marine sediments. The amount and reactivity of organic matter, iron minerals and concentrations of dissolved sulfide in pore water control the burial of iron sulfide and organic bound sulfur in marine sediments. Here we investigate the sulfidization process in a sediment core from the western part of upper Bay of Bengal fan characterized by efficient burial of organic matter with siliclastic load. A 30 m long sediment core (MD 161/29, Lat. 170 18.04' N, Long. 870 22.56' E, water depth: 2434m) was collected onboard Marion Dufresne (May, 2007) and studied for Fe-S speciation and organic matter characterization. Buffered dithionite extractable iron (FeD) varies from 0.71 to 1.43 wt % (Avg. 0.79 wt %). FeD represents Fe oxides and oxyhydroxides mainly, ferrihydrite, lepidocrocite, goethite and hematite. Acid volatile sulfur (AVS) varies from 0.0015 to 0.63 wt % (avg: 0.058 wt %), while chromium reducible sulfur (CRS) varies from 0.00047 to 0.29 wt % (avg. 0.054 wt %). Based on the vertical distribution patterns of FeD, AVS and CRS, the core is divided into three zones, the lower (3000 to 1833 cm), middle (1833 to 398 cm) and upper (398 cm to surface) zones. FeD shows higher concentration in the lower zone. FeTR (FeOx + FeD + FeCRS + FeAVS) also exhibit higher concentration in this zone, suggesting higher availability of reactive iron for iron sulfide precipitation. AVS, elemental sulfur, spikes of CRS and gradual enrichment of δ34SAVS and δ34SCRS with sharp peaks in-between is noted in the lower zone. The gradual enrichment of δ34SAVS and δ34SCRS is the outcome of late diagenetic pyritization with higher availability of sulfide

  9. Bond strength of masonry

    NARCIS (Netherlands)

    Pluijm, van der R.; Vermeltfoort, A.Th.

    1992-01-01

    Bond strength is not a well defined property of masonry. Normally three types of bond strength can be distinguished: - tensile bond strength, - shear (and torsional) bond strength, - flexural bond strength. In this contribution the behaviour and strength of masonry in deformation controlled uniaxial

  10. Rietveld refinement of the structures of 1.0 C-S-H and 1.5 C-S-H

    KAUST Repository

    Battocchio, Francesco; Monteiro, Paulo J.M.; Wenk, Hans-Rudolf

    2012-01-01

    Low-Q region Rietveld analyses were performed on C-S-H synchrotron XRD patterns, using the software MAUD. Two different crystal structures of tobermorite 11 Å were used as a starting model: monoclinic ordered Merlino tobermorite, and orthorhombic

  11. Understanding Bonds - Denmark

    DEFF Research Database (Denmark)

    Rimmer, Nina Røhr

    2016-01-01

    Undervisningsmateriale. A bond is a debt security, similar to an ”I Owe You document” (IOU). When you purchase a bond, you are lending money to a government, municipality, corporation, federal agency or other entity known as the issuer. In return for the loan, the issuer promises to pay you...... a specified rate of interest during the life of the bond and to repay the face value of the bond (the principal) when it “matures,” or comes due. Among the types of bonds you can choose from are: Government securities, municipal bonds, corporate bonds, mortgage and asset-backed securities, federal agency...... securities and foreign government bonds....

  12. Wire bonding in microelectronics

    CERN Document Server

    Harman, George G

    2010-01-01

    Wire Bonding in Microelectronics, Third Edition, has been thoroughly revised to help you meet the challenges of today's small-scale and fine-pitch microelectronics. This authoritative guide covers every aspect of designing, manufacturing, and evaluating wire bonds engineered with cutting-edge techniques. In addition to gaining a full grasp of bonding technology, you'll learn how to create reliable bonds at exceedingly high yields, test wire bonds, solve common bonding problems, implement molecular cleaning methods, and much more. Coverage includes: Ultrasonic bonding systems and technologies, including high-frequency systems Bonding wire metallurgy and characteristics, including copper wire Wire bond testing Gold-aluminum intermetallic compounds and other interface reactions Gold and nickel-based bond pad plating materials and problems Cleaning to improve bondability and reliability Mechanical problems in wire bonding High-yield, fine-pitch, specialized-looping, soft-substrate, and extreme-temperature wire bo...

  13. Laccase-catalyzed C-S and C-C coupling for a one-pot synthesis of 1,4-naphthoquinone sulfides and 1,4-naphthoquinone sulfide dimers

    CSIR Research Space (South Africa)

    Wellington, Kevin W

    2013-06-01

    Full Text Available Oxidative C-S and C-C bond formation with aryl and alkyl thiols was catalyzed under mild conditions in a reaction vessel open to air at pH 4.5 in the presence of a commercial laccase (Novozym 51003 or Suberase) and a cosolvent (DMF) to afford 1...

  14. Rietveld refinement of the structures of 1.0 C-S-H and 1.5 C-S-H

    KAUST Repository

    Battocchio, Francesco

    2012-11-01

    Low-Q region Rietveld analyses were performed on C-S-H synchrotron XRD patterns, using the software MAUD. Two different crystal structures of tobermorite 11 Å were used as a starting model: monoclinic ordered Merlino tobermorite, and orthorhombic disordered Hamid tobermorite. Structural modifications were required to adapt the structures to the chemical composition and the different interlayer spacing of the C-S-H samples. Refinement of atomic positions was done by using special constraints called fragments that maintain interatomic distances and orientations within atomic polyhedra. Anisotropic crystallite size refinement showed that C-S-H has a nanocrystalline disordered structure with a preferred direction of elongation of the nanocrystallites in the plane of the Ca interlayer. The quality of the fit showed that the monoclinic structure gives a more adequate representation of C-S-H, whereas the disordered orthorhombic structure can be considered a more realistic model if the lack of long-range order of the silica chain along the c-direction is assumed. © 2012 Elsevier Ltd. All rights reserved.

  15. Bonding with Your Baby

    Science.gov (United States)

    ... the future bonding of the child and parent. Adoptive parents may be concerned about bonding with their ... general emotional support. And it's OK to ask family members and friends for help in the days — ...

  16. C/S data processing system and its application on DECnet

    International Nuclear Information System (INIS)

    Jin Zhigang; Shu Yantai

    1997-01-01

    Because of the rapid development of PC and LAN, C/S data processing paradigm became the main stream of distributed processing. For the family of VAX which running VMS operating system, in order to implement a C/S system, the authors must solve some problems and take efforts to implement inter-process communication between VAX and PC. The authors introduce how to construct a C/S system in the VAX-PC heterogeneous environment. The authors also describe the practical method by an example of the data processing system for fusion experiment. At last, the result of performance evaluation and comparison of the centralized processing and C/S system confirmed that the latter has some advantages

  17. Australia's Bond Home Bias

    OpenAIRE

    Anil V. Mishra; Umaru B. Conteh

    2014-01-01

    This paper constructs the float adjusted measure of home bias and explores the determinants of bond home bias by employing the International Monetary Fund's high quality dataset (2001 to 2009) on cross-border bond investment. The paper finds that Australian investors' prefer investing in countries with higher economic development and more developed bond markets. Exchange rate volatility appears to be an impediment for cross-border bond investment. Investors prefer investing in countries with ...

  18. Phenylacetylene and H bond

    Indian Academy of Sciences (India)

    ... all resembling H bonds. Non-linear H bonds due to secondary interactions. C-H stretching frequency shows blue shift. Heavy atom distances are longer than the sum of van der Waals radii. Formed a task group through IUPAC to come up with a modern definition of H bond. 15 international experts including Desiraju.

  19. Chemical bond fundamental aspects of chemical bonding

    CERN Document Server

    Frenking, Gernot

    2014-01-01

    This is the perfect complement to ""Chemical Bonding - Across the Periodic Table"" by the same editors, who are two of the top scientists working on this topic, each with extensive experience and important connections within the community. The resulting book is a unique overview of the different approaches used for describing a chemical bond, including molecular-orbital based, valence-bond based, ELF, AIM and density-functional based methods. It takes into account the many developments that have taken place in the field over the past few decades due to the rapid advances in quantum chemica

  20. An estimation of applicable thermodynamic data for C-S-H gel to PHREEQC

    International Nuclear Information System (INIS)

    Kato, Hiroshige; Honda, Akira

    2004-07-01

    Cementitious materials will be used extensively in the TRU waste repository. The dissolution/precipitation of cementitious materials will affect the chemical condition of pore waster of TRU waste repository. Thus, it is important for estimation of chemical condition of pore water to apply the dissolution/precipitation of cementitious materials appropriately. A C-S-H gel (poorly crystallized calcium silicate hydrate) is a major component in cementitious materials which determined the mechanical characteristics of cementitious materials. The hydraulic condition of cementitious materials is strongly affected by the dissolution/precipitation of C-S-H gel due to the change of porosity accompanied with the dissolution/precipitation processes. Further, the chemical condition of pore water will be dominated by the dissolution/ precipitation of C-S-H gel for a long period. Therefore, an importance of the dissolution/precipitation of C-S-H gel has been recognized internationally, and several dissolution/precipitation models of C-S-H gel have been proposed. The principal scopes of the C-S-H gel models are description of an incongruent dissolution/precipitation behavior of C-S-H gel. On the other hand, PHREEQC is a compute program, which has been used generally for the geochemical calculation. PHREEQC can provide the state of chemical equilibrium of system defined by chemical equations and equilibrium constants (log K). In JNC, reference model groundwater determined by calculation using PHREEQC in HLW study will be also used in TRU waste study. In addition, PHREEQC will be used for calculation of the cement-water reaction. Therefore, applicability of the presented dissolution/precipitation models of C-S-H gel to PHREEQC was estimated. As a result of estimation of the applicability, Atkinson model and Reardon model were selected as suitable models to the PHREEQC. The chemical equations and log K values of C-S-H gel were derived from these models and tested using PHREEQC. The

  1. Effect of temperature on the microstructure of calcium silicate hydrate (C-S-H)

    Energy Technology Data Exchange (ETDEWEB)

    Gallucci, E., E-mail: gallucci.emmanuel@ch.sika.com; Zhang, X.; Scrivener, K.L.

    2013-11-15

    Temperature affects the properties of concrete through its effect on the hydration of cement and its associated microstructural development. This paper focuses on the modifications to C-S-H induced by isothermal curing between 5 and 60 °C. The results show that as the temperature increases (within the range studied) the C/S ratio of C-S-H changes only slightly, with a higher degree of polymerisation of silicate chains, but there is a significant decrease in its bound water content and an increase of apparent density of 25%. This increase seems to come from a different packing of C-S-H at the nanoscale. As a consequence of these changes, the microstructure of the cement paste is much coarser and porous, which explains the lower final strengths obtained by curing at elevated temperatures. -- Highlights: •C-S-H structure studied at the atomic level •Multiple analytical techniques used •Studies conducted at temperatures above and below normal temperatures.

  2. CS Bond formation by

    Indian Academy of Sciences (India)

    2017-02-02

    Feb 2, 2017 ... a thiol substituent at position-2 of the quinazoline ring. ... coupling reactions represent great contribution to the recent growth of organic synthesis.2 ... Difficulties in C-S ...... Experimental Advances (Amsterdam: Elsevier) 19; (b).

  3. Computational Material Modeling of Hydrated Cement Paste Calcium Silicate Hydrate (C-S-H) Chemistry Structure - Influence of Magnesium Exchange on Mechanical Stiffness: C-S-H Jennite

    Science.gov (United States)

    2015-04-27

    MODELING OF C-S-H Material chemistry level modeling following the principles and techniques commonly grouped under Computational Material Science is...Henmi, C. and Kusachi, I. Monoclinic tobermorite from fuka, bitchu-cho, Okoyama Perfecture. Japan J. Min. Petr. Econ . Geol. (1989)84:374-379. [22...31] Liu, Y. et al. First principles study of the stability and mechanical properties of MC (M=Ti, V, Zr, Nb, Hf and Ta) compounds. Journal of Alloys and Compounds. (2014) 582:500-504. 10

  4. BONDING ALUMINUM METALS

    Science.gov (United States)

    Noland, R.A.; Walker, D.E.

    1961-06-13

    A process is given for bonding aluminum to aluminum. Silicon powder is applied to at least one of the two surfaces of the two elements to be bonded, the two elements are assembled and rubbed against each other at room temperature whereby any oxide film is ruptured by the silicon crystals in the interface; thereafter heat and pressure are applied whereby an aluminum-silicon alloy is formed, squeezed out from the interface together with any oxide film, and the elements are bonded.

  5. Incorporation of zinc into calcium silicate hydrates, Part I: formation of C-S-H(I) with C/S=2/3 and its isochemical counterpart gyrolite

    International Nuclear Information System (INIS)

    Stumm, Andreas; Garbev, Krassimir; Beuchle, Guenter; Black, Leon; Stemmermann, Peter; Nueesch, Rolf

    2005-01-01

    We have investigated the incorporation of zinc into both nanocrystalline and crystalline calcium silicate hydrates with starting C/S ratios of 2/3 (0.66). Zinc was added replacing calcium in the starting mixtures [Zn/(Zn+Ca)=0-1/4; 0-10 wt.% Zn], and the resultant phases were characterised using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), differential thermal analysis-thermogravimetry (DTA-TG) and environmental scanning electron microscopy (ESEM). In both groups of samples, increasing zinc content led to gradual structural changes, until eventually a second phase was formed. Zinc was incorporated to similar limits in both sets of samples. The thermal stability of the structures increased to a certain zinc content, beyond which there was structural destabilisation. Zinc incorporation is possible up to ∼6 wt.%. Our observations strongly indicate similar zinc incorporation mechanisms in both sample series, namely incorporation of zinc into the interlayer of C-S-H(I) and the X-sheet of gyrolite for nanocrystalline and crystalline samples, respectively

  6. Copper wire bonding

    CERN Document Server

    Chauhan, Preeti S; Zhong, ZhaoWei; Pecht, Michael G

    2014-01-01

    This critical volume provides an in-depth presentation of copper wire bonding technologies, processes and equipment, along with the economic benefits and risks.  Due to the increasing cost of materials used to make electronic components, the electronics industry has been rapidly moving from high cost gold to significantly lower cost copper as a wire bonding material.  However, copper wire bonding has several process and reliability concerns due to its material properties.  Copper Wire Bonding book lays out the challenges involved in replacing gold with copper as a wire bond material, and includes the bonding process changes—bond force, electric flame off, current and ultrasonic energy optimization, and bonding tools and equipment changes for first and second bond formation.  In addition, the bond–pad metallurgies and the use of bare and palladium-coated copper wires on aluminum are presented, and gold, nickel and palladium surface finishes are discussed.  The book also discusses best practices and re...

  7. C&S Enterprise, L.L.C. - Clean Water Act Public Notice

    Science.gov (United States)

    The EPA is providing notice of a proposed Administrative Penalty Assessment against C & S Enterprise, L.L.C. (“Respondent”), a business located at 2454 480th Ave, Deep River, IA 52222, for alleged violations of the Clean Water Act at property owned by Resp

  8. Dorothy L. Sayers and C. S. Lewis: Christian Postmodernism beyond Boundaries

    Science.gov (United States)

    Yuasa, Kyoko

    2012-01-01

    Modern critics do not consider science fiction and mystery novels to be "serious reading", but Dorothy L. Sayers and C. S. Lewis questioned the boundaries between "popular" and "serious" literature. Both Christian writers critically discuss the spiritual crisis of the modern world in each fiction genre. This paper…

  9. C. S. Peirce's Complementary and Transdisciplinary Conception of Science and Religion

    DEFF Research Database (Denmark)

    Brier, Søren

    2012-01-01

    C. S. Peirce was very mathematical, logical and empirical in the foundations of his thinking and he saw no principal limits to the knowledge obtainable by science. But the transdisciplinary view he developed differs substantially from the unity science of logical positivism in that he worked...

  10. Os diagramas de C. S. Peirce para as dez classes de signos

    Directory of Open Access Journals (Sweden)

    Priscila Lena Farias

    2013-12-01

    Full Text Available Uma seção da Gramática Especulativa de C.S.Peirce - Dez classes de signos - recebeu, a partir de 1903, um importante tratamento diagramático. Neste artigo, são apresentados e discutidos dois diagramas desenvolvidos por Peirce para as dez classes, incluindo esboços desses modelos.

  11. An Integrated Perspective of Humanism and Supernaturalism for Education: C. S. Lewis's Version of Education

    Science.gov (United States)

    Lee, Seung Chun

    2013-01-01

    This paper explores some theoretical reflections on the connection between C. S. Lewis's thoughts on the purpose and process of education and his understanding of supernatural human nature which has been relatively little explored. An introduction about Lewis's career as a college teacher blends into the background of this paper. It is followed by…

  12. Scinticisternography and scintiventriculography. A study of C.S.F. dynamics

    NARCIS (Netherlands)

    Front, Dov

    1971-01-01

    The problem of C.S.F. flow and absorption has attracted many different disciplines in medicine. The normal physiology and the pathology, which declares itself mainly by hydrocephalus, have been intensively studied by neurophysiologists, neurologists and neurosurgeons. The possibility of treating

  13. Paradise Lost and Found: Obedience, Disobedience, and Storytelling in C.S. Lewis and Philip Pullman.

    Science.gov (United States)

    Wood, Naomi

    2001-01-01

    Considers how in the fantasy series "The Chronicles of Narnia" and "His Dark Materials," by C.S. Lewis and Philip Pullman respectively, the authors use symbols and themes from "Paradise Lost." Notes that each author's narrative choice uses his view of cosmic order to persuade readers that obedience should be…

  14. Oral Interpretation of C.S. Lewis'"Narnia Tales": A Refracting of "Pictures."

    Science.gov (United States)

    Keefe, Carolyn

    "The Chronicles of Narnia" are a series of seven fairy tales written by C.S. Lewis that have become popular with both children and adults. Lewis points to five aspects of the fairy tale form that made the form suitable for expressing the images he saw. The aspects are: (1) no love interest; (2) no close psychology; (3) severe restraints…

  15. Transversely Compressed Bonded Joints

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  16. Corporate Bonds in Denmark

    DEFF Research Database (Denmark)

    Tell, Michael

    2015-01-01

    Corporate financing is the choice between capital generated by the corporation and capital from external investors. However, since the financial crisis shook the markets in 2007–2008, financing opportunities through the classical means of financing have decreased. As a result, corporations have...... to think in alternative ways such as issuing corporate bonds. A market for corporate bonds exists in countries such as Norway, Germany, France, the United Kingdom and the United States, while Denmark is still behind in this trend. Some large Danish corporations have instead used foreign corporate bonds...... markets. However, NASDAQ OMX has introduced the First North Bond Market in December 2012 and new regulatory framework came into place in 2014, which may contribute to a Danish based corporate bond market. The purpose of this article is to present the regulatory changes in Denmark in relation to corporate...

  17. study of the effect of aluminum content and c / s ratio on the physico ...

    African Journals Online (AJOL)

    31 déc. 2014 ... Ce travail expérimental a pour objectif de montrer que la valorisation du sable de dunes du Sahara de l'Algérie est tout à fait pertinente dans la production de béton cellulaire, et que le rapport C/S ainsi que le dosage en Aluminium possèdent une importante influence sur les propriétés de ce type de béton.

  18. Ettringite and C-S-H Portland cement phases for waste ion immobilization: A review

    International Nuclear Information System (INIS)

    Gougar, M.L.D.; Scheetz, B.E.; Roy, D.M.

    1996-01-01

    The formation, structure and chemistry of the ettringite and C-S-H phases of Portland cement have been reviewed as they relate to waste ion immobilization. The purpose of this review was to investigate the use of Portland cement as a host for priority metallic pollutants as identified by the Environmental Protection Agency and as a host for radioactive waste ions as identified in 40 CFR 191. Ettringite acts as host to a number of these ions in both the columnar and channel sections of the crystal structure. Substitutions have been made at the calcium, aluminum, hydroxide and sulfate sites. C-S-H also hosts a number of the waste species in both ionic and salt form. Immobilization mechanisms for C-S-H include sorption, phase mixing and substitution. The following ions have not apparently been reported as specifically immobilized by one of these phases: Ag, Am, Np, Pu, Ra, Tc, Th and Sn; however, some of these ions are immobilized by Portland cement

  19. Safeguards evolution towards unattended c/s (containment and surveillance) systems

    International Nuclear Information System (INIS)

    Valentino, Lucia I.; Saavedra, Analia D.; Castro, Laura B.; Maceiras, Elena; Llacer, Carlos D.; Vicens, Hugo E.; Mairal, Maria L.; Fernandez Moreno, Sonia

    2000-01-01

    This paper shows the development and evolution of safeguards towards the use of different containment and surveillance (C/S) systems, which involve the possibility of working unattended. They are designed to transmit safeguards relevant data remotely. It is believed that they would increase safeguards efficiency while maintaining or even enhancing their effectiveness. At present, unattended C/S systems with or without remote transmission are in place at several installations. In addition, some other possible applications are being tested. One of these is the Remote Monitoring Systems (RMS) field trial at Embalse nuclear power plant to cover the transfers of spent fuel from the ponds to the dry storage. Some of the matters to be addressed are of general nature (i.e. applicable to any unattended/remote system) while others depend on the specific application in a nuclear installation. Among others, the following are particularly important: -) Sharing of data with the SSAC; -) Impact of a failure of the RMS on the operator, IAEA and the SSAC; -) Provision of relevant operational and accounting information; -) Review of the current safeguard approach for the selected installation; -) RMS cost-effectiveness assessment. This paper describes the status of the RMS field trial as well as the current C/S system in place at Embalse nuclear power plant. (authors)

  20. Bond markets in Africa

    Directory of Open Access Journals (Sweden)

    Yibin Mu

    2013-07-01

    Full Text Available African bond markets have been steadily growing in recent years, but nonetheless remain undeveloped. African countries would benefit from greater access to financing and deeper financial markets. This paper compiles a unique set of data on government securities and corporate bond markets in Africa. It then applies an econometric model to analyze the key determinants of African government securities market and corporate bond market capitalization. Government securities market capitalization is directly related to better institutions and interest rate volatility, and inversely related to smaller fiscal deficits, higher interest rate spreads, exchange rate volatility, and current and capital account openness. Corporate bond market capitalization is directly linked to economic size, the level of development of the economy and financial markets, better institutions, and interest rate volatility, and inversely related to higher interest rate spreads and current account openness. Policy implications follow.

  1. Chemical alteration of calcium silicate hydrates in saline groundwater. Mechanism of sorption of Na on C-S-H and effect of NaCl on leaching of Ca from C-S-H

    International Nuclear Information System (INIS)

    Sugiyama, Daisuke; Fujita, Tomonari

    2004-01-01

    In the concept for TRU waste disposal in Japan, cement is a potential waste packaging and backfilling material and is expected to provide chemical containment. In the presence of some reactive ions in a saline groundwater, the chemical properties of cement materials should be affected. In this study, the mechanism of sorption of sodium (Na) on C-S-H and the effect of sodium chloride (NaCl) concentration on dissolution of Calcium Silicate Hydrate (C-S-H) are discussed by measuring the sorption isotherm of sodium onto C-S-H gel (Ca/Si = 0.65-1.2). Based on the experimental results, it is showed that sodium sorbs by substitution for Ca in C-S-H phases and leaching of Ca from C-S-H is enhanced in NaCl solution ( -1 mol dm -3 ). The results of sorption experiments are reasonably well modelled by the ion-exchange model assuming some calcium sites with different ion-exchange log K values. It is also suggested that the dissolution of C-S-H can be modelled reasonably well by considering the effect of ionic strength on activity coefficients of aqueous species for high Ca/Si ratio of C-S-H, and the effect of exchange of sodium with calcium of C-S-H on leaching of Ca becomes obvious for lower Ca/Si ratio of C-S-H. (author)

  2. Handbook of wafer bonding

    CERN Document Server

    Ramm, Peter; Taklo, Maaike M V

    2011-01-01

    Written by an author and editor team from microsystems companies and industry-near research organizations, this handbook and reference presents dependable, first-hand information on bonding technologies.In the first part, researchers from companies and institutions around the world discuss the most reliable and reproducible technologies for the production of bonded wafers. The second part is devoted to current and emerging applications, including microresonators, biosensors and precise measuring devices.

  3. Diffusion bonding techniques

    International Nuclear Information System (INIS)

    Peters, R.D.

    1978-01-01

    The applications of diffusion bonding at the General Electric Neutron Devices Department are briefly discussed, with particular emphasis on the gold/gold or gold/indium joints made between metallized alumina ceramic parts in the vacuum switch tube and the crystal resonator programs. Fixtures which use the differential expansion of dissimilar metals are described and compared to one that uses hydraulic pressure to apply the necessary bonding force

  4. C. S. Peirce’s Semiotic Answer to the Riddle of Consciousness

    DEFF Research Database (Denmark)

    Brier, Søren

    A scientific explanation of consciousness that is not partially based on phenomenology seems logically impossible. C.S. Peirce’s pragmaticist semiotics attempts to bridge the gap between natural sciences and humanities by combining a phenomenological approach with an evolutionary and realistic...... understanding of nature and society in the development of a new transdisicplinary and evolutionary theory of meaning and logic in a semiotic theory of mind and consciousness. Though a contributor to the development of modern logic and science Peirce, through inventing a semiotics that embraced phenomenology...

  5. DMA Controller for LEON3 SoC:s Using AMBA

    OpenAIRE

    Nilsson, Emelie

    2013-01-01

    A DMA Controller can offload a processor tremendously. A memory copy operation can be initiated by the processor and while the processor executes others tasks the memory copy can be fulfilled by the DMA Controller. An implementation of a DMA Controller for use in LEON3 SoC:s has been made during this master thesis. Problems that occurred while designing a controller of this type concerned AMBA buses, data transfers, alignment and interrupt handling. The DMA Controller supports AMBA and is att...

  6. Romanian government bond market

    Directory of Open Access Journals (Sweden)

    Cornelia POP

    2012-12-01

    Full Text Available The present paper aims to present the level of development reached by Romanian government bond market segment, as part of the country financial market. The analysis will be descriptive (the data series available for Romania are short, based on the secondary data offered by the official bodies involved in the process of issuing and trading the Romanian government bonds (Romanian Ministry of Public Finance, Romanian National Bank and Bucharest Stock Exchange, and also on secondary data provided by the Federation of European Stock Exchanges.To enhance the market credibility as a benchmark, a various combination of measures is necessary; among these measures are mentioned: the extension of the yield curve; the issuance calendars in order to improve transparency; increasing the disclosure of information on public debt issuance and statistics; holding regular meetings with dealers, institutional investors and rating agencies; introducing a system of primary dealers; establishing a repurchase (repo market in the government bond market. These measures will be discussed based on the evolution presented inside the paper.The paper conclude with the fact that, until now, the Romanian government bond market did not provide a benchmark for the domestic financial market and that further efforts are needed in order to increase the government bond market transparency and liquidity.

  7. Interstellar hydrogen bonding

    Science.gov (United States)

    Etim, Emmanuel E.; Gorai, Prasanta; Das, Ankan; Chakrabarti, Sandip K.; Arunan, Elangannan

    2018-06-01

    This paper reports the first extensive study of the existence and effects of interstellar hydrogen bonding. The reactions that occur on the surface of the interstellar dust grains are the dominant processes by which interstellar molecules are formed. Water molecules constitute about 70% of the interstellar ice. These water molecules serve as the platform for hydrogen bonding. High level quantum chemical simulations for the hydrogen bond interaction between 20 interstellar molecules (known and possible) and water are carried out using different ab-intio methods. It is evident that if the formation of these species is mainly governed by the ice phase reactions, there is a direct correlation between the binding energies of these complexes and the gas phase abundances of these interstellar molecules. Interstellar hydrogen bonding may cause lower gas abundance of the complex organic molecules (COMs) at the low temperature. From these results, ketenes whose less stable isomers that are more strongly bonded to the surface of the interstellar dust grains have been observed are proposed as suitable candidates for astronomical observations.

  8. Safe and Liquid Mortgage Bonds

    DEFF Research Database (Denmark)

    Dick-Nielsen, Jens; Gyntelberg, Jacob; Lund, Jesper

    This paper shows that strict match pass-through funding of covered bonds provides safe and liquid mortgage bonds. Despite a 30% drop in house prices during the 2008 global crisis Danish mortgage bonds remained as liquid as most European government bonds. The Danish pass-through system effectively...... eliminates credit risk from the investor's perspective. Similar to other safe bonds, funding liquidity becomes the main driver of mortgage bond liquidity and this creates commonality in liquidity across markets and countries. These findings have implications for how to design a robust mortgage bond system...

  9. Hydrogen bonded supramolecular materials

    CERN Document Server

    Li, Zhan-Ting

    2015-01-01

    This book is an up-to-date text covering topics in utilizing hydrogen bonding for constructing functional architectures and supramolecular materials. The first chapter addresses the control of photo-induced electron and energy transfer. The second chapter summarizes the formation of nano-porous materials. The following two chapters introduce self-assembled gels, many of which exhibit unique functions. Other chapters cover the advances in supramolecular liquid crystals and the versatility of hydrogen bonding in tuning/improving the properties and performance of materials. This book is designed

  10. Continuing bonds and place.

    Science.gov (United States)

    Jonsson, Annika; Walter, Tony

    2017-08-01

    Where do people feel closest to those they have lost? This article explores how continuing bonds with a deceased person can be rooted in a particular place or places. Some conceptual resources are sketched, namely continuing bonds, place attachment, ancestral places, home, reminder theory, and loss of place. The authors use these concepts to analyze interview material with seven Swedes and five Britons who often thought warmly of the deceased as residing in a particular place and often performing characteristic actions. The destruction of such a place, by contrast, could create a troubling, haunting absence, complicating the deceased's absent-presence.

  11. Consciousness and C. S. Peirce’s Answer to the Riddle of the Sphinx

    DEFF Research Database (Denmark)

    Brier, Søren

    2016-01-01

    on phenomenology seems logically impossible therefore the many (unsuccessful) attempts to naturalize. C.S. Peirce’s pragmaticist semiotics attempts to bridge the gap between natural sciences and humanities by combining a phenomenological approach with an evolutionary and realistic understanding of nature...... and society in the development of a semiotic theory of mind and consciousness. Though a contributor to the development of modern logic and science Peirce, through inventing a semiotics that embraced phenomenology, tried to heal the split Husserl saw. Philosophy aims primarily at the kind of knowledge...... that gives unity and system to the whole body of human, social and natural basic sciences through a critical examination of the grounds of our convictions, prejudices, and beliefs. Where Husserl wanted to heal the split he observed through his pure phenomenology, Peirce integrated his semiotics with a pure...

  12. Asm-Triggered too Observations of 100,000 C/s Black Hole Candidates

    Science.gov (United States)

    van der Klis, Michiel

    Resubmission accepted Cycle 2-9 proposal. The PCA is unique by the high count rates (~100,000 c/s) it can record, and its resulting extreme sensitivity to weak variability. Only few sources get this bright. Our RXTE work on Sco X-1 and 1744-28 shows that high count rate observations are very rewarding, but also difficult and not without risk. In the life og the satallire probably only one black-hole transient (if any) will reach 10^5 cps/5PCU levels. when this occurs, a window of discovery will be opened on black holes, which will nearly certainly close again within a few days. This proposal aims at ensuring that optimal use is made of this opportunity by performing state of the art high count rate observations covering all of the most crucial aspects of the source variability.

  13. ASM Triggered too Observations of 100,000 C/s Black-Hole Candidates

    Science.gov (United States)

    van der Klis, Michiel

    Resubmission accepted Cycle 2-11 proposal. The PCA is unique by the high count rates (~100.000 c/s) it can record, and its resulting extreme sensitivity to weak variability. Only few sources get this bright. Our RXTE work on Sco X-1 and 1744-28 shows that high count rate observations are very rewarding, but also difficult and not without risk. In the life of the satellite probably only one black hole transient (if any) will reach 10^5 cps/5 PCU levels. When this occurs a window of discovery will be opened on black holes, which will nearly certainly close again within a few days. This proposal aims at ensuring that optimal use is made of this opportunity by performing state of the art high count rate observations covering all of the most crusial aspects of the source variability.

  14. Dark science and techno-utopia: the conservative approach of C. S. Lewis

    Directory of Open Access Journals (Sweden)

    Mario Ramos Vera

    2017-08-01

    Full Text Available The rise of scientific, illustrated and progressive late nineteenth century utopias triggered proposals with alternative meanings. Some of those were articulated through a conservative thought as well as a christian, transcendent and otherworldly metanarrative. C. S. Lewis, for example, provided his answer to the techno-utopia in his essay The Abolition of Man as well as in the novel That Hideous Strength —conclusion of the Cosmic Trilogy (or Ransom Trilogy. We will introduce his challenge through three different arguments: (1 contrary to the project of personality conditioning , education is a link of continuity with the past and of respect for tradition; (2 in the light of the methodological atheism of these dystopias elicited the metaphysical and transcendent lewisian foundation of the imperfection of the human condition; (3 He will reply to the arrogance of social and political engineering by reducing power to a technical criterion of instrumental knowledge with the modest language of politics.

  15. Integration of European Bond Markets

    DEFF Research Database (Denmark)

    Christiansen, Charlotte

    2014-01-01

    I investigate the time variation in the integration of EU government bond markets. The integration is measured by the explanatory power of European factor portfolios for the individual bond markets for each year. The integration of the government bond markets is stronger for EMU than non-EMU memb......I investigate the time variation in the integration of EU government bond markets. The integration is measured by the explanatory power of European factor portfolios for the individual bond markets for each year. The integration of the government bond markets is stronger for EMU than non...

  16. Effet de la poudre de verre sur le fluage du C-S-H

    Science.gov (United States)

    Danilova, Maryna

    Glass is a unique inert material that could be recycled many times without changing its physical and chemical properties. Nevertheless, for some reason, large quantities of glass are still not recycled and therefore are stored as a waste. Its alternative recycling has become, since long, a major environmental problem. Moreover, glass is a potentially useful material for the development of ecological concrete, consequently, this way valorization seems to be imminent. In this research, characterization of the creep of concrete incorporating waste glass in powder form, i.e. glass powder (GP) as a supplementary cementitious material (GP-concrete) was carried out at a macro- and nanolevels. First, results from experimental study on the under load behaviour of GP-concrete are presented. Different types of strain occurring under load or after unload were discussed: quasi-instantaneous deformation, total mechanical deformation due to the maintained uniaxial compressive load during 1 year, total creep, basic creep, elastic recovery and total recovery. Shrinkage under drying conditions and endogenous shrinkage were also studied. After 1 year creep, the effects of constant load and drying on residual strength were also examined. A comparison was made concerning the final state of the porosity. Afterwards, the thesis reveals the results of tests conducted on the cement paste, going down to its composition and properties of the hydrated phases, in particular of calcium silicate hydrates (C-S-H). All of this, in order to conclude on the harmlessness use of GP regarding to the creep. Keywords : Glass powder, Air-entrained concrete, Creep, Shrinkage, C-S-H, Nanoindentation

  17. Amalgam shear bond strength to dentin using different bonding agents.

    Science.gov (United States)

    Vargas, M A; Denehy, G E; Ratananakin, T

    1994-01-01

    This study evaluated the shear bond strength of amalgam to dentin using five different bonding agents: Amalgambond Plus, Optibond, Imperva Dual, All-Bond 2, and Clearfil Liner Bond. Flat dentin surfaces obtained by grinding the occlusal portion of 50 human third molars were used for this study. To contain the amalgam on the tooth surface, cylindrical plastic molds were placed on the dentin and secured with sticky wax. The bonding agents were then applied according to the manufacturers' instructions or light activated and Tytin amalgam was condensed into the plastic molds. The samples were thermocycled and shear bond strengths were determined using an Instron Universal Testing Machine. Analysis by one-way ANOVA indicated significant difference between the five groups (P < 0.05). The bond strength of amalgam to dentin was significantly higher with Amalgambond Plus using the High-Performance Additive than with the other four bonding agents.

  18. Compositional Evolution of Calcium Silicate Hydrate (C-S-H) Structures by Total X-Ray Scattering

    KAUST Repository

    Soyer-Uzun, Sezen

    2011-12-09

    High-energy X-ray diffraction was employed to study the structural characteristics of a set of C-S-H samples with 0.6 ≤ C/S a;circ 1.75. It has been observed that Si is tetrahedrally coordinated to O for all samples irrespective of chemical composition and the Ca-O coordination number gradually decreases from ∼7 to ∼6 with increasing C/S ratio. This suggests that the C-S-H structure evolves from a tobermorite-like structure into a jennite-like structure as a function of increasing C/S ratio as the interlayer space decreases from ∼1.3 to ∼1 nm. Evolution of these short- and medium-range order structural characteristics in the C-S-H system is associated with the alteration of the Ca-O layers and silicate depolymerization with increasing C/S. © 2011 The American Ceramic Society.

  19. Compositional Evolution of Calcium Silicate Hydrate (C-S-H) Structures by Total X-Ray Scattering

    KAUST Repository

    Soyer-Uzun, Sezen; Chae, Sejung Rosie; Benmore, Chris J.; Wenk, Hans-Rudolf; Monteiro, Paulo J. M.

    2011-01-01

    High-energy X-ray diffraction was employed to study the structural characteristics of a set of C-S-H samples with 0.6 ≤ C/S a;circ 1.75. It has been observed that Si is tetrahedrally coordinated to O for all samples irrespective of chemical composition and the Ca-O coordination number gradually decreases from ∼7 to ∼6 with increasing C/S ratio. This suggests that the C-S-H structure evolves from a tobermorite-like structure into a jennite-like structure as a function of increasing C/S ratio as the interlayer space decreases from ∼1.3 to ∼1 nm. Evolution of these short- and medium-range order structural characteristics in the C-S-H system is associated with the alteration of the Ca-O layers and silicate depolymerization with increasing C/S. © 2011 The American Ceramic Society.

  20. Convertible bond valuation focusing on Chinese convertible bond market

    OpenAIRE

    Yang, Ke

    2010-01-01

    This paper mainly discusses the methods of valuation of convertible bonds in Chinese market. Different from common convertible bonds in European market, considering the complicate features of Chinese convertible bond, this paper represents specific pricing approaches for pricing convertible bonds with different provisions along with the increment of complexity of these provisions. More specifically, this paper represents the decomposing method and binomial tree method for pricing both of Non-...

  1. PONDEROSA-C/S: client–server based software package for automated protein 3D structure determination

    OpenAIRE

    Lee, Woonghee; Stark, Jaime L.; Markley, John L.

    2014-01-01

    Peak-picking Of Noe Data Enabled by Restriction Of Shift Assignments-Client Server (PONDEROSA-C/S) builds on the original PONDEROSA software (Lee et al. in Bioinformatics 27:1727–1728. doi:10.1093/bioinformatics/btr200, 2011) and includes improved features for structure calculation and refinement. PONDEROSA-C/S consists of three programs: Ponderosa Server, Ponderosa Client, and Ponderosa Analyzer. PONDEROSA-C/S takes as input the protein sequence, a list of assigned chemical shifts, and nucle...

  2. Comparison of shear bond strength of the stainless steel metallic brackets bonded by three bonding systems

    Directory of Open Access Journals (Sweden)

    Mehdi Ravadgar

    2013-09-01

    Full Text Available Introduction: In orthodontic treatment, it is essential to establish a satisfactory bond between enamel and bracket. After the self-etch primers (SEPs were introduced for the facilitation of bracket bonding in comparison to the conventional etch-and-bond system, multiple studies have been carried out on their shear bond strengths which have yielded different results. This study was aimed at comparing shear bond strengths of the stainless steel metallic brackets bonded by three bonding systems. Methods: In this experimental in vitro study, 60 extracted human maxillary premolar teeth were randomly divided into three equal groups: in the first group, Transbond XT (TBXT light cured composite was bonded with Transbond plus self-etching primer (TPSEP in the second group, TBXT composite was bonded with the conventional method of acid etching and in the third group, the self cured composite Unite TM bonding adhesive was bonded with the conventional method of acid etching. In all the groups, Standard edgewise-022 metallic brackets (American Orthodontics, Sheboygan, USA were used. Twenty-four hours after the completion of thermocycling, shear bond strength of brackets was measured by Universal Testing Machine (Zwick. In order to compare the shear bond strengths of the groups, the variance analysis test (ANOVA was adopted and p≤0.05 was considered as a significant level. Results: Based on megapascal, the average shear bond strength for the first, second, and third groups was 8.27±1.9, 9.78±2, and 8.92±2.5, respectively. There was no significant difference in the shear bond strength of the groups. Conclusions: Since TPSEP shear bond strength is approximately at the level of the conventional method of acid etching and within the desirable range for orthodontic brackets shear bond strength, applying TPSEP can serve as a substitute for the conventional method of etch and bond, particularly in orthodontic operations.

  3. Comparison of shear bond strength of the stainless steel metallic brackets bonded by three bonding systems

    Directory of Open Access Journals (Sweden)

    Mehdi Ravadgar

    2013-09-01

    Full Text Available Introduction: In orthodontic treatment, it is essential to establish a satisfactory bond between enamel and bracket. After the self-etch primers (SEPs were introduced for the facilitation of bracket bonding in comparison to the conventional etch-and-bond system, multiple studies have been carried out on their shear bond strengths which have yielded different results. This study was aimed at comparing shear bond strengths of the stainless steel metallic brackets bonded by three bonding systems. Methods: In this experimental in vitro study, 60 extracted human maxillary premolar teeth were randomly divided into three equal groups: in the first group, Transbond XT (TBXT light cured composite was bonded with Transbond plus self-etching primer (TPSEP; in the second group, TBXT composite was bonded with the conventional method of acid etching; and in the third group, the self cured composite Unite TM bonding adhesive was bonded with the conventional method of acid etching. In all the groups, Standard edgewise-022 metallic brackets (American Orthodontics, Sheboygan, USA were used. Twenty-four hours after the completion of thermocycling, shear bond strength of brackets was measured by Universal Testing Machine (Zwick. In order to compare the shear bond strengths of the groups, the variance analysis test (ANOVA was adopted and p≤0.05 was considered as a significant level. Results: Based on megapascal, the average shear bond strength for the first, second, and third groups was 8.27±1.9, 9.78±2, and 8.92±2.5, respectively. There was no significant difference in the shear bond strength of the groups. Conclusions: Since TPSEP shear bond strength is approximately at the level of the conventional method of acid etching and within the desirable range for orthodontic brackets shear bond strength, applying TPSEP can serve as a substitute for the conventional method of etch and bond, particularly in orthodontic operations.

  4. Why are Hydrogen Bonds Directional?

    Indian Academy of Sciences (India)

    century and most chemists appear to think of 'chemi- cal bond' as ..... These complexes, in their global min- ima, have ... taneously act as hydrogen bond donor and acceptor displaying ... also has a local minimum, which is linear and similar to.

  5. Bond yield curve construction

    Directory of Open Access Journals (Sweden)

    Kožul Nataša

    2014-01-01

    Full Text Available In the broadest sense, yield curve indicates the market's view of the evolution of interest rates over time. However, given that cost of borrowing it closely linked to creditworthiness (ability to repay, different yield curves will apply to different currencies, market sectors, or even individual issuers. As government borrowing is indicative of interest rate levels available to other market players in a particular country, and considering that bond issuance still remains the dominant form of sovereign debt, this paper describes yield curve construction using bonds. The relationship between zero-coupon yield, par yield and yield to maturity is given and their usage in determining curve discount factors is described. Their usage in deriving forward rates and pricing related derivative instruments is also discussed.

  6. Corporate Hybrid Bonds

    OpenAIRE

    Ahlberg, Johan; Jansson, Anton

    2016-01-01

    Hybrid securities do not constitute a new phenomenon in the Swedish capital markets. Most commonly, hybrids issued by Swedish real estate companies in recent years are preference shares. Corporate hybrid bonds on the other hand may be considered as somewhat of a new-born child in the family of hybrid instruments. These do, as all other hybrid securities, share some equity-like and some debt-like characteristics. Nevertheless, since 2013 the interest for the instrument has grown rapidly and ha...

  7. Hybrid Cat Bonds

    OpenAIRE

    Barrieu, Pauline; Louberge, Henri

    2009-01-01

    Natural catastrophes attract regularly the attention of media and have become a source of public concern. From a financial viewpoint, natural catastrophes represent idiosyncratic risks, diversifiable at the world level. But for reasons analyzed in this paper reinsurance markets are unable to cope with this risk completely. Insurance-linked securities, such as cat bonds, have been issued to complete the international risk transfer process, but their development is disappointing so far. This pa...

  8. Temperature Effects on Tensile and Compressive Mechanical Behaviors of C-S-H Structure via Atomic Simulation

    Directory of Open Access Journals (Sweden)

    Hao Xin

    2017-01-01

    Full Text Available An atomic scale model of amorphous calcium silicate hydrate (C-S-H with Ca/Si ratio of 1.67 is constructed. Effects of temperature on mechanical properties of C-S-H structure under tensile and compressive loading in the layered direction are investigated via molecular dynamics simulations. Results from present simulations show that (1 the tensile strength and Young’s modulus of C-S-H structure significantly decrease with the increase of the temperature; (2 the water layer plays an important role in the mechanical properties of C-S-H structure; (3 the compressive strength is stronger than tensile strength, which corresponds with the characteristic of cement paste.

  9. Optimal Investment in Structured Bonds

    DEFF Research Database (Denmark)

    Jessen, Pernille; Jørgensen, Peter Løchte

    The paper examines the role of structured bonds in the optimal portfolio of a small retail investor. We consider the typical structured bond essentially repacking an exotic option and a zero coupon bond, i.e. an investment with portfolio insurance. The optimal portfolio is found when the investment...

  10. 46 CFR Sec. 10 - Bonds.

    Science.gov (United States)

    2010-10-01

    ... REPAIRS UNDER NATIONAL SHIPPING AUTHORITY MASTER LUMP SUM REPAIR CONTRACT-NSA-LUMPSUMREP Sec. 10 Bonds. (a... awarded work and the furnishing of the performance and payment bonds required by Article 14 of the NSA... of the NSA-LUMPSUMREP Contract, the standard form of individual performance bond (Standard Form 25...

  11. Progress report for FACETS (Framework Application for Core-Edge Transport Simulations): C.S. SAP

    Energy Technology Data Exchange (ETDEWEB)

    Epperly, T W

    2008-10-01

    The mission of the Computer Science Scientific Application Partnership (C.S. SAP) at LLNL is to develop and apply leading-edge scientific component technology to FACETS software. Contributions from LLNL's fusion energy program staff towards the underlying physics modules are described in a separate report. FACETS uses component technology to combine selectively multiple physics and solver software modules written in different languages by different institutions together in an tightly-integrated, parallel computing framework for Tokamak reactor modeling. In the past fiscal year, the C.S. SAP has focused on two primary tasks: applying Babel to connect UEDGE into the FACETS framework through UEDGE's existing Python interface and developing a next generation componentization strategy for UEDGE which avoids the use of Python. The FACETS project uses Babel to solve its language interoperability challenges. Specific accomplishments for the year include: (1) Refined SIDL interfaces for UEDGE to meet satisfy the standard interfaces required by FACETS for all physics modules. This required consensus building between framework and UEDGE developers. (2) Wrote prototype C++ driver for UEDGE to demonstrate how UEDGE can be called from C++ using Babel. (3) Supported the FACETS project by adding new features to Babel such as release number tagging, porting to new machines, and adding new configuration options. Babel modifications were delivered to FACETS by testing and publishing development snapshots in the projects software repository. (4) Assisted Tech-X Corporation in testing and debugging of a high level build system for the complete FACETS tool chain--the complete list of third-party software libraries that FACETS depends on directly or indirectly (e.g., MPI, HDF5, PACT, etc.). (5) Designed and implemented a new approach to wrapping UEDGE as a FACETS component without requiring Python. To get simulation results as soon as possible, our initial connection from the

  12. Progress report for FACETS (Framework Application for Core-Edge Transport Simulations): C.S. SAP

    International Nuclear Information System (INIS)

    Epperly, T.W.

    2008-01-01

    The mission of the Computer Science Scientific Application Partnership (C.S. SAP) at LLNL is to develop and apply leading-edge scientific component technology to FACETS software. Contributions from LLNL's fusion energy program staff towards the underlying physics modules are described in a separate report. FACETS uses component technology to combine selectively multiple physics and solver software modules written in different languages by different institutions together in an tightly-integrated, parallel computing framework for Tokamak reactor modeling. In the past fiscal year, the C.S. SAP has focused on two primary tasks: applying Babel to connect UEDGE into the FACETS framework through UEDGE's existing Python interface and developing a next generation componentization strategy for UEDGE which avoids the use of Python. The FACETS project uses Babel to solve its language interoperability challenges. Specific accomplishments for the year include: (1) Refined SIDL interfaces for UEDGE to meet satisfy the standard interfaces required by FACETS for all physics modules. This required consensus building between framework and UEDGE developers. (2) Wrote prototype C++ driver for UEDGE to demonstrate how UEDGE can be called from C++ using Babel. (3) Supported the FACETS project by adding new features to Babel such as release number tagging, porting to new machines, and adding new configuration options. Babel modifications were delivered to FACETS by testing and publishing development snapshots in the projects software repository. (4) Assisted Tech-X Corporation in testing and debugging of a high level build system for the complete FACETS tool chain--the complete list of third-party software libraries that FACETS depends on directly or indirectly (e.g., MPI, HDF5, PACT, etc.). (5) Designed and implemented a new approach to wrapping UEDGE as a FACETS component without requiring Python. To get simulation results as soon as possible, our initial connection from the FACETS

  13. The chemical bond in inorganic chemistry the bond valence model

    CERN Document Server

    Brown, I David

    2016-01-01

    The bond valence model is a version of the ionic model in which the chemical constraints are expressed in terms of localized chemical bonds formed by the valence charge of the atoms. Theorems derived from the properties of the electrostatic flux predict the rules obeyed by both ionic and covalent bonds. They make quantitative predictions of coordination number, crystal structure, bond lengths and bond angles. Bond stability depends on the matching of the bonding strengths of the atoms, while the conflicting requirements of chemistry and space lead to the structural instabilities responsible for the unusual physical properties displayed by some materials. The model has applications in many fields ranging from mineralogy to molecular biology.

  14. Representations of mind: C. S. Sherrington and scientific opinion, c. 1930-1950.

    Science.gov (United States)

    Smith, R

    2001-12-01

    Recent writers in the brain sciences and the philosophy of mind contrast modern biological theories of consciousness with a mind-body dualism supposedly dominant half-a-century ago which they regard as scientifically sterile. Reference to C. S. Sherrington often signals the rejected dualism. This paper re-examines Sherrington's highly qualified position and links it to the arguments of British scientists for whom he was a figurehead in the 1930s and 1940s. I interpret the mind-body literature as ancillary to debates about cultural values. From this perspective, dualism represents a defense of a threatened conservative culture. Dismissal of scientists' supposed "dualism" does little to illuminate the tension in their thought between defense of values traditionally associated with mind and hope for an integrated mind-body science. This leads to comments on Sherrington's own concept of integration. The conclusion relates these points to the new research in the brain sciences evident by the end of the 1940s.

  15. Hydrogen bonding in ionic liquids.

    Science.gov (United States)

    Hunt, Patricia A; Ashworth, Claire R; Matthews, Richard P

    2015-03-07

    Ionic liquids (IL) and hydrogen bonding (H-bonding) are two diverse fields for which there is a developing recognition of significant overlap. Doubly ionic H-bonds occur when a H-bond forms between a cation and anion, and are a key feature of ILs. Doubly ionic H-bonds represent a wide area of H-bonding which has yet to be fully recognised, characterised or explored. H-bonds in ILs (both protic and aprotic) are bifurcated and chelating, and unlike many molecular liquids a significant variety of distinct H-bonds are formed between different types and numbers of donor and acceptor sites within a given IL. Traditional more neutral H-bonds can also be formed in functionalised ILs, adding a further level of complexity. Ab initio computed parameters; association energies, partial charges, density descriptors as encompassed by the QTAIM methodology (ρBCP), qualitative molecular orbital theory and NBO analysis provide established and robust mechanisms for understanding and interpreting traditional neutral and ionic H-bonds. In this review the applicability and extension of these parameters to describe and quantify the doubly ionic H-bond has been explored. Estimating the H-bonding energy is difficult because at a fundamental level the H-bond and ionic interaction are coupled. The NBO and QTAIM methodologies, unlike the total energy, are local descriptors and therefore can be used to directly compare neutral, ionic and doubly ionic H-bonds. The charged nature of the ions influences the ionic characteristics of the H-bond and vice versa, in addition the close association of the ions leads to enhanced orbital overlap and covalent contributions. The charge on the ions raises the energy of the Ylp and lowers the energy of the X-H σ* NBOs resulting in greater charge transfer, strengthening the H-bond. Using this range of parameters and comparing doubly ionic H-bonds to more traditional neutral and ionic H-bonds it is clear that doubly ionic H-bonds cover the full range of weak

  16. Additional disulfide bonds in insulin

    DEFF Research Database (Denmark)

    Vinther, Tine N; Pettersson, Ingrid; Huus, Kasper

    2015-01-01

    The structure of insulin, a glucose homeostasis-controlling hormone, is highly conserved in all vertebrates and stabilized by three disulfide bonds. Recently, we designed a novel insulin analogue containing a fourth disulfide bond located between positions A10-B4. The N-terminus of insulin's B......-chain is flexible and can adapt multiple conformations. We examined how well disulfide bond predictions algorithms could identify disulfide bonds in this region of insulin. In order to identify stable insulin analogues with additional disulfide bonds, which could be expressed, the Cβ cut-off distance had...... in comparison to analogues with additional disulfide bonds that were more difficult to predict. In contrast, addition of the fourth disulfide bond rendered all analogues resistant to fibrillation under stress conditions and all stable analogues bound to the insulin receptor with picomolar affinities. Thus...

  17. Leaching of both calcium hydroxide and C-S-H from cement paste: Modeling the mechanical behavior

    International Nuclear Information System (INIS)

    Carde, C.; Torrenti, J.M.; Francois, R.

    1996-01-01

    This paper deals with the effect of the leaching process of cement based materials on their mechanical properties. This process induces mainly a total leaching of Ca(OH) 2 and a progressive decalcification of C-S-H which leads to a gradient of C/S ratio in the leaching zone. In a previous work, the authors venture the hypothesis that the dissolution of calcium hydroxide was the essential parameter governing both decrease in strength and increase in porosity in the case of a paste sample made with an OPC cement which leads to a 20% content of calcium. In order to quantify the effect of the decrease of C/S ratio in C-S-H, the authors have performed experiments on paste samples with the admixture of silica fume to reduce the content of calcium hydroxide and thus emphasize the effect of C/S ratio decrease of the C-S-H. The leaching process was achieved by the use of a 50% concentrate solution of ammonium nitrate. Compression tests were conducted on micro-cylinder samples (10, 12, 14, 20 and 30 mm of diameter) because of the slow kinetics of degradation due to the leaching. The deterioration of the cement paste and the mortar exposed to the action of the ammonium nitrate was indicated by a peripheral zone of less resistance. The experimental results allow the modeling of the mechanical behavior of cement pastes in relation to the ratio of degraded area over total area of the sample A d /A t . The model thus defined allows separation of the effect of calcium hydroxide leaching and C-S-H leaching, and shows the importance of the first one. The current research program tries to characterize the deterioration of the mechanical properties of the concrete surrounding radioactive wastes, due to the water flow during storage

  18. Effect of the hydration temperature on the microstructure of Class G cement: C-S-H composition and density

    International Nuclear Information System (INIS)

    Bahafid, Sara; Ghabezloo, Siavash; Duc, Myriam; Faure, Pamela; Sulem, Jean

    2017-01-01

    Curing temperature has a significant influence on cement paste microstructure and the properties of its principal hydrate C-S-H. In this paper, the effect of the hydration temperature in the range of 7 °C to 90 °C on the microstructure of a class G oil-well cement is studied. This is done by combining various experimental methods, including X-ray diffraction associated with the Rietveld analysis, thermo-gravimetric analysis, mercury intrusion porosimetry and porosity evaluation by drying. The experimental results show an increase of the capillary porosity and a decrease of the gel porosity by increasing the hydration temperature. This is attributed to a decrease of the C-S-H intrinsic porosity and a corresponding increase of the C-S-H density for higher curing temperatures. The experimental results are used in a simple analysis method to evaluate the density of C-S-H, as well as its C/S ratio and H/S ratio in dry and saturated conditions. The evaluated C-S-H density varies from 1.88 g/cm 3 at 7 °C to 2.10 g/cm 3 at 90 °C. The results also show a decrease of molar C/S ratio with increasing hydration temperature from 1.93 at 7 °C to 1.71 at 90 °C and of the H/S ratio from 5.1 at 7 °C to 2.66 at 90 °C.

  19. Interaction of calcium silicate hydrates (C-S-H), the main components of cement, with alkaline chlorides, analogy with clays

    International Nuclear Information System (INIS)

    Viallis-Terrisse, H.

    2000-01-01

    This work, belonging to a more general study on the structure and reactivity of cement, deals with the experimental and theoretical analysis of the interaction of alkaline chlorides with calcium silicate hydrates (C-S-H), the main components of cement paste. The interaction of alkaline cations with C-S-H is interfacial, involving both electrostatic and surface complexation mechanisms. The C-S-H surface is constituted of silanol sites, partially dissociated due to the high pH of the interstitial solution. The calcium ions, present in large amounts in the equilibrium solution of C-S-H, constitute potential determining ions for the C-S-H surface. The alkaline ions seem to compete with calcium for the same surface sites. The adsorption isotherms show that caesium presents a better affinity than sodium and lithium for the C-S-H surface. Moreover, solid-state NMR suggests that caesium forms with the surface sites inner-sphere complexes, whereas sodium seems to keep its hydration sphere. These results are in agreement with zeta potential measurements, which let suppose a specific adsorption of caesium ions, and an indifferent behaviour of both other alkaline ions. A model for the C-S-H surface was proposed, from the electric double layer model, and mass action laws expressing the complexation of the different ionic species with the silanol sites. The whole study relies on a structural analogy with smectites, some clays presenting well-known cationic adsorption properties. The structural similarity between both minerals is enhanced by some similarities of reactivity, though significant behaviour differences could also be noted. (author)

  20. Ransom, Religion, and Red Giants: C.S. Lewis and Fred Hoyle

    Science.gov (United States)

    Larsen, Kristine

    2010-01-01

    Famed fantasy writer C.S. Lewis (1898-1963) was known to friends as a well-read astronomy aficionado. However, this medieval scholar and Christian apologist embraced a pre-Copernican universe (with its astrological overtones) in his Chronicles of Narnia series and defended the beauty and relevance of the geocentric model in his final academic work, "The Discarded Image". In the "Ransom Trilogy” ("Out of the Silent Planet", "Perelandra", and "That Hideous Strength") philologist Ransom (loosely based on Lewis's close friend J.R.R. Tolkien) travels to Lewis's visions of Mars and Venus, where he interacts with intelligent extraterrestrials, battles with evil scientists, and aids in the continuation of extraterrestrial Christian values. In the final book, Ransom is joined by a handful of colleagues in open warfare against the satanic N.I.C.E. (National Institute for Coordinated Experiments). Geneticist and evolutionary biologist J.B.S. Haldane criticized Lewis for his scientifically inaccurate descriptions of the planets, and his disdain for the scientific establishment. Lewis responded to the criticism in essays of his own. Another of Lewis's favorite scientific targets was atheist Fred Hoyle, whom he openly criticized for anti-Christian statements in Hoyle's BBC radio series. Writer and Lewis friend Dorothy L. Sayers voiced her own criticism of Hoyle. In a letter, Lewis dismissed Hoyle as "not a great philosopher (and none of my scientific colleagues think much of him as a scientist.” Given Lewis's lack of respect for Hoyle, and use of creative license in describing the planets, and the flat-earth, "geocentric” Narnia, it is surprising that Lewis very carefully includes an astronomically correct description of red giants in two novels in the Narnia series ("The Magician's Nephew" and "The Last Battle"). This inclusion is even more curious given that Fred Hoyle is well-known as one of the pioneers in the field of stellar death and the properties of red giants.

  1. Fatigue aging of adhesive bonds

    International Nuclear Information System (INIS)

    DeLollis, N.J.

    1979-01-01

    A year long study has been made of the effect of fatigue on the bond between two epoxy encapsulant formulations and a fused alumina disc. The variables studied included isothermal aging at temperatures up to and including the cure temperature and cyclic thermal aging from +74 to -54 0 C. The encapsulants were glass microballoon filled epoxies differing only in curing agents. One was cured with an aromatic amine eutectic (Shell Curing Agent Z). The other was cured with diethanolamine. The Z cured encapsulant bond failed completely at the bond interface with little or no aging; infrared evidence indicated a soluble interlayer as a possible cause of failure. The diethanolamine cured encapsulant survived a year of isothermal aging with little or no evidence of bond degradation. Cyclic thermal aging resulted in gradual bond failure with time. An extrapolation of the cyclic aging data indicates that the stresses induced by thermal cycling would result in complete bond failure in about 1200 days

  2. Thermodynamic description of the solubility of C-S-H gels in hydrated Portland cement. Literature review

    International Nuclear Information System (INIS)

    Soler, J.M.

    2007-11-01

    The objective of this study is to compile the available information published in the scientific literature regarding the solubility of C-S-H (calcium silica hydrate) gels, which are the main components of hydrated Portland cement. Modeling the thermodynamic properties of C-S-H, including its incongruent dissolution behavior, is an important requirement to understand the evolution and degradation of hydrated cement and concrete. The thermodynamic modeling of C-S-H started with the use of empirical or semi-empirical models and evolved to the application of solid solution models. Most of the experimental work has been performed at or near 25 deg C and the models are in principle applicable to temperatures near 25 deg C. One of the models provides an explicit dependence on temperature. (orig.)

  3. $\\chi^{\\vphantom\\dagger}_{c0}(3915)$ As the Lightest $c\\bar c s \\bar s$ State

    CERN Document Server

    Lebed, Richard F.

    2016-05-23

    The state $\\chi^{\\vphantom\\dagger}_{c0}(3915)$ has recently been demoted by the Particle Data Group from its previous status as the conventional $c\\bar c$ $2 {}^3P_0$ state, largely due to the absence of expected $D\\bar D$ decays. We propose that $\\chi^{\\vphantom\\dagger}_{c0}(3915)$ is actually the lightest $c\\bar c s \\bar s$ state, and calculate the spectrum of such states using the diquark model, identifying many of the observed charmoniumlike states that lack open-charm decay modes as $c\\bar c s \\bar s$. Among other results, we argue that $Y(4140)$ is a $J^{PC} = 1^{++}$ $c\\bar c s \\bar s$ state that has been not been seen in two-photon fusion largely as a consequence of the Landau-Yang theorem.

  4. UV Photofragmentation Dynamics of Protonated Cystine: Disulfide Bond Rupture.

    Science.gov (United States)

    Soorkia, Satchin; Dehon, Christophe; Kumar, S Sunil; Pedrazzani, Mélanie; Frantzen, Emilie; Lucas, Bruno; Barat, Michel; Fayeton, Jacqueline A; Jouvet, Christophe

    2014-04-03

    Disulfide bonds (S-S) play a central role in stabilizing the native structure of proteins against denaturation. Experimentally, identification of these linkages in peptide and protein structure characterization remains challenging. UV photodissociation (UVPD) can be a valuable tool in identifying disulfide linkages. Here, the S-S bond acts as a UV chromophore and absorption of one UV photon corresponds to a σ-σ* transition. We have investigated the photodissociation dynamics of protonated cystine, which is a dimer of two cysteines linked by a disulfide bridge, at 263 nm (4.7 eV) using a multicoincidence technique in which fragments coming from the same fragmentation event are detected. Two types of bond cleavages are observed corresponding to the disulfide (S-S) and adjacent C-S bond ruptures. We show that the S-S cleavage leads to three different fragment ions via three different fragmentation mechanisms. The UVPD results are compared to collision-induced dissociation (CID) and electron-induced dissociation (EID) studies.

  5. What is a hydrogen bond?

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. What is a hydrogen bond? Precise definition of a hydrogen bond is still elusive!1. Several criteria are listed usually for X-H•••Y, X and Y initially thought to be F, O and N only1. Structural: The X-Y bond length is less than the sum of their van der Waals radii. X-H•••Y is ...

  6. Composite interlayer for diffusion bonding

    International Nuclear Information System (INIS)

    1976-01-01

    A ductile interlayer is described, which is useful for transient liquid phase diffusion bonding of metallic articles; the interlayer consisting of a melting point depressant and a plurality of ductile lamellae which are free from carbides, aluminides and borides. The composition and fabrication of the lamellae, and the process for bonding the metallic articles, depend on the composition of the metals to be bonded, and are exemplified in the specification. (U.K.)

  7. Wafer bonding applications and technology

    CERN Document Server

    Gösele, Ulrich

    2004-01-01

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

  8. A simplified indirect bonding technique

    Directory of Open Access Journals (Sweden)

    Radha Katiyar

    2014-01-01

    Full Text Available With the advent of lingual orthodontics, indirect bonding technique has become an integral part of practice. It involves placement of brackets initially on the models and then their transfer to teeth with the help of transfer trays. Problems encountered with current indirect bonding techniques used are (1 the possibility of adhesive flash remaining around the base of the brackets which requires removal (2 longer time required for the adhesive to gain enough bond strength for secure tray removal. The new simplified indirect bonding technique presented here overcomes both these problems.

  9. Human Bond Communication

    DEFF Research Database (Denmark)

    Prasad, Ramjee

    2016-01-01

    Modern dexterous communication technology is progressively enabling humans to communicate their information through them with speech (aural) and media (optical) as underpinning essence. Humans realize this kind of aural and optical information by their optical and auditory senses. However, due...... to certain constraints, the ability to incorporate the other three sensory features namely, olfactory, gustatory, and tactile are still far from reality. Human bond communication is a novel concept that incorporates olfactory, gustatory, and tactile that will allow more expressive and holistic sensory...... information exchange through communication techniques for more human sentiment centric communication. This concept endorses the need of inclusion of other three senses and proposes an innovative approach of holistic communication for future communication network....

  10. 30 CFR 281.33 - Bonds and bonding requirements.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Bonds and bonding requirements. 281.33 Section 281.33 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF MINERALS OTHER THAN OIL, GAS, AND SULPHUR IN THE OUTER CONTINENTAL SHELF Financial Considerations § 281.33...

  11. Superconducting joint of Bi-2223/Ag superconducting tapes by diffusion bonding

    International Nuclear Information System (INIS)

    Guo Wei; Zou Guisheng; Wu Aiping; Wang Yanjun; Bai Hailin; Ren Jialie

    2009-01-01

    61-Filaments Bi-2223/Ag superconducting tapes have been joined by diffusion bonding. The critical currents (I C s) of the joints are obtained by using standard four probe method under no magnetic field in the liquid nitrogen. The microstructures of the joints are evaluated by the electron microscope in electron backscatter diffraction mode and the phase compositions of the superconducting cores of the joint and the original tape are determined by X-ray diffraction (XRD). The results show diffusion bonding is effective bonding technique for HTS tapes, and the bonding time is reduced greatly from hundreds of hours to a few hours, and the bonding pressure also changes from 140-4000 MPa to 3 MPa. Furthermore, the diffusion bonding joints sustain superconducting properties, and the critical current ratios (CCR O ) of the joints are in the range of 35%-80%. Microstructures of the typical joint display a good bonding and some defects existed in traditional method are avoided. XRD results show that the phase compositions of the superconducting cores have no obvious changes before and after diffusion bonding, which offers physical and material bases for high superconducting property of the joints.

  12. 29 CFR 2580.412-19 - Term of the bond, discovery period, other bond clauses.

    Science.gov (United States)

    2010-07-01

    ... SECURITY ACT OF 1974 TEMPORARY BONDING RULES General Bond Rules § 2580.412-19 Term of the bond, discovery... 29 Labor 9 2010-07-01 2010-07-01 false Term of the bond, discovery period, other bond clauses... new bond must be obtained each year. There is nothing in the Act that prohibits a bond for a term...

  13. O hydrogen bonds in alkaloids

    Indian Academy of Sciences (India)

    An overview of general classification scheme, medicinal importance and crystal structure analysis with emphasis on the role of hydrogen bonding in some alkaloids is presented in this paper. The article is based on a general kind of survey while crystallographic analysis and role of hydrogen bonding are limited to only ...

  14. Distance criterion for hydrogen bond

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Distance criterion for hydrogen bond. In a D-H ...A contact, the D...A distance must be less than the sum of van der Waals Radii of the D and A atoms, for it to be a hydrogen bond.

  15. Optimal Investment in Structured Bonds

    DEFF Research Database (Denmark)

    Jessen, Pernille; Jørgensen, Peter Løchte

    2012-01-01

    of the article is to provide possible explanations for the puzzle of why small retail investors hold structured bonds. The investment universe consists of a stock index, a risk-free bank account, and a structured bond containing an option written on another index. We apply expected utility maximization...

  16. Fusion-bonded fluidic interconnects

    NARCIS (Netherlands)

    Fazal, I.; Elwenspoek, Michael Curt

    2008-01-01

    A new approach to realize fluidic interconnects based on the fusion bonding of glass tubes with silicon is presented. Fusion bond strength analyses have been carried out. Experiments with plain silicon wafers and coated with silicon oxide and silicon nitride are performed. The obtained results are

  17. The uptake of Cs, Cl, I, Co, U and Pu by C-S-H, portlandite and ettringite

    International Nuclear Information System (INIS)

    Le Callonnec, C.; Richet, C.; Ayache, R.

    2000-01-01

    The aim of this work is to study the retention of Pu, Cs, Cl, U, Co and I onto the three phases of a cement paste: calcium silicate hydrates or C-S-H (Ca/Si=1.65), portlandite (Ca(OH) 2 ) and ettringite (Ca 6 Al 2 S 3 O 21 .32H 2 O). C-S-H of Ca/Si molar ratio of 1.65 and ettringite were prepared in suspension, while portlandite was provided by an industrial laboratory. The sorptive power for each ion was determined by a batch model at 20 degrees Celsius. The uptake of ions onto the phases has been obtained by introducing a very small volume of radioactive Cs, Co, Cl, I, U and Pu solution in each batch. Aliquots of solution were periodically removed for analysis. The results show that there are two kinds of ions whatever the solid phase: those which are poorly sorbed: Cs, Cl, I and Co, U and Pu which are strongly sorbed (by a factor 100 to 10000). Elsewhere, the comparison between the sorptive power of each phase reveals that C-S-H develops a significant sorption potential for pluri-valent ions (Pu, U, Co) as well as for Cl. The retention capacity of portlandite mainly towards pluri-valent cations is one or two orders of magnitude weaker than C-S-H capacity. Ettringite only plays a sorptive role relatively to Cs. However, iodine does not have a strong affinity for any solid at all. The data allow us to calculate a global sorption coefficient Kd of the cement paste for each ion. Assuming that the proportion of C-S-H, portlandite, ettringite is respectively 65%, 15% and 5% in a Portland cement, the global sorption coefficient is in good agreement with literature regarding on U, Cs, I and Cl. Cementitious materials appear to be an interesting chemical barrier that can limit the diffusion of pluri-valent cations. As C-S-H represent from 60% to 75% of the cement paste, this study leads to underline that C-S-H is mainly responsible for the retention capacity of cementitious materials specially towards U, Pu, Co, Cl although its sorption power is limited concerning

  18. SOCIAL BONDING: REGULATION BY NEUROPEPTIDES

    Directory of Open Access Journals (Sweden)

    Claudia eLieberwirth

    2014-06-01

    Full Text Available Affiliative social relationships (e.g., among spouses, family members, and friends play an essential role in human society. These relationships affect psychological, physiological, and behavioral functions. As positive and enduring bonds are critical for the overall well-being of humans, it is not surprising that considerable effort has been made to study the neurobiological mechanisms that underlie social bonding behaviors. The present review details the involvement of the nonapeptides, oxytocin (OT and arginine vasopressin (AVP, in the regulation of social bonding in mammals including humans. In particular, we will discuss the role of OT and AVP in the formation of social bonds between partners of a mating pair as well as between parents and their offspring. Furthermore, the role of OT and AVP in the formation of interpersonal bonding involving trust is also discussed.

  19. Fusion-bonded fluidic interconnects

    International Nuclear Information System (INIS)

    Fazal, I; Elwenspoek, M C

    2008-01-01

    A new approach to realize fluidic interconnects based on the fusion bonding of glass tubes with silicon is presented. Fusion bond strength analyses have been carried out. Experiments with plain silicon wafers and coated with silicon oxide and silicon nitride are performed. The obtained results are discussed in terms of the homogeneity and strength of fusion bond. High pressure testing shows that the bond strength is large enough for most applications of fluidic interconnects. The bond strength for 525 µm thick silicon, with glass tubes having an outer diameter of 6 mm and with a wall thickness of 2 mm, is more than 60 bars after annealing at a temperature of 800 °C

  20. Sibling bereavement and continuing bonds.

    Science.gov (United States)

    Packman, Wendy; Horsley, Heidi; Davies, Betty; Kramer, Robin

    2006-11-01

    Historically, from a Freudian and medical model perspective, emotional disengagement from the deceased was seen as essential to the successful adaptation of bereavement. A major shift in the bereavement literature has occurred and it is now generally accepted that despite the permanence of physical separation, the bereaved remains involved and connected to the deceased and can be emotionally sustained through continuing bonds. The majority of literature has focused on adults and on the nature of continuing bonds following the death of a spouse. In this article, the authors demonstrate how the continuing bonds concept applies to the sibling relationship. We describe the unique continued relationship formed by bereaved children and adolescents following a sibling loss, highlight the factors that influence the siblings continuing bonds expressions, and offer clinical interventions. In our view, mental health professionals can play an important role in helping parents encourage activities that may facilitate the creation and maintenance of continuing bonds in their children.

  1. PONDEROSA-C/S: client-server based software package for automated protein 3D structure determination.

    Science.gov (United States)

    Lee, Woonghee; Stark, Jaime L; Markley, John L

    2014-11-01

    Peak-picking Of Noe Data Enabled by Restriction Of Shift Assignments-Client Server (PONDEROSA-C/S) builds on the original PONDEROSA software (Lee et al. in Bioinformatics 27:1727-1728. doi: 10.1093/bioinformatics/btr200, 2011) and includes improved features for structure calculation and refinement. PONDEROSA-C/S consists of three programs: Ponderosa Server, Ponderosa Client, and Ponderosa Analyzer. PONDEROSA-C/S takes as input the protein sequence, a list of assigned chemical shifts, and nuclear Overhauser data sets ((13)C- and/or (15)N-NOESY). The output is a set of assigned NOEs and 3D structural models for the protein. Ponderosa Analyzer supports the visualization, validation, and refinement of the results from Ponderosa Server. These tools enable semi-automated NMR-based structure determination of proteins in a rapid and robust fashion. We present examples showing the use of PONDEROSA-C/S in solving structures of four proteins: two that enable comparison with the original PONDEROSA package, and two from the Critical Assessment of automated Structure Determination by NMR (Rosato et al. in Nat Methods 6:625-626. doi: 10.1038/nmeth0909-625 , 2009) competition. The software package can be downloaded freely in binary format from http://pine.nmrfam.wisc.edu/download_packages.html. Registered users of the National Magnetic Resonance Facility at Madison can submit jobs to the PONDEROSA-C/S server at http://ponderosa.nmrfam.wisc.edu, where instructions, tutorials, and instructions can be found. Structures are normally returned within 1-2 days.

  2. Structure phenomena in the bond zone of explosively bonded plates

    International Nuclear Information System (INIS)

    Livne, Z.

    1979-12-01

    In the bond areas of couples of explosively bonded plates, there are often zones, generally designated as ''molten pockets'', which have undergone melting and solidification. The object of the present study was to investigate molten pockets, which have a decisive effect on bond quality. The experimental samples for the study were chosen in consideration of the mutual behaviour of the plates constituting the couples, according to their equilibrium phase diagrams. To facilitate the investigation, large plates were bonded under conditions that enabled to to obtain wavy bond zones that included relatively large molten pockets. To clarify the complex nature of molten pockets and their surroundings, a wide variety of methods were employed. It was found that the shape and composition of molten pockets largely depend upon the mechanism of formation of both the bond wave and the molten pockets. It was also found that the composition of molten pockets is not homogeneous, which is manifest in the modification of the composition of the pockets, the solidification morphology, the phases, which have been identified by X-ray diffraction, and the bond strenght and hardness. Moreover, the different solidification morphologies revealed by metallography were found to depend upon the types of plates bonded, the bonding conditions and the location of pockets in the wavy interface. For molten pockets, cooling rates of 10 4 to 10 5 (degC/sec) have been deduced from interdendritic spacing, and found to be in good agreement with calculations after a mathematical model. It seems that the fast cooling rates and the steep temperature gradients are at the origin of the particular solidification phenomena observed in molten pockets

  3. Dentin-bonding agents

    Directory of Open Access Journals (Sweden)

    João Carlos Gomes

    2008-01-01

    Full Text Available New dental restorative materials have been developed to meet not only the functional demands, but esthetics as well, and in the last few years an enormous range of new materials has appeared for use in dentistry. Among them, several adhesive systems, and different operative techniques for each group materials. Therefore, is indispensable for the professional to know about the properties, characteristics, and association of these materials with the dental structures, in order to select and use them correctly. Should conventional self-etching adhesive systems be used? This question encouraged this literature review to be conducted, with the aim of comparing the conventional adhesive systems with the self-etching systems and to look for scientific data that would help professionals to choose which adhesive system to use. When compared to conventional systems, it was noted that the self-etching systems show less sensitivity to technique, especially as regards errors the operator could commit. The self-etching systems, particularly the 2-step type, have shown equivalent values of bond strength, marginal microleakage and performance, therefore, will be an option for direct composite resin restorations in posterior teeth.

  4. Carbon-sulfur bond formation by reductive elimination of gold(iii) thiolates.

    Science.gov (United States)

    Currie, Lucy; Rocchigiani, Luca; Hughes, David L; Bochmann, Manfred

    2018-04-10

    Whereas the reaction of the gold(iii) pincer complex (C^N^C)AuCl with 1-adamantyl thiol (AdSH) in the presence of base affords (C^N^C)AuSAd, the same reaction in the absence of base leads to formation of aryl thioethers as the products of reductive elimination of the Au-C and Au-S ligands (C^N^C = dianion of 2-6-diphenylpyridine or 2-6-diphenylpyrazine). Although high chemical stability is usually taken as a characteristic of pincer complexes, results show that thiols are capable of cleaving one of the pincer Au-C bonds. This reaction is not simply a function of S-H acidity, since no cleavage takes place with other more acidic X-H compounds, such as carbazole, amides, phenols and malonates. The reductive C-S elimination follows a second-order rate law, -d[1a]/dt = k[1a][AdSH]. Reductive elimination is enabled by displacement of the N-donor by thiol; this provides the conformational flexibility necessary for C-S bond formation to occur. Alternatively, reductive C-S bond formation can be induced by reaction of pre-formed thiolates (C^N^C)AuSR with a strong Brønsted acid, followed by addition of SMe2 as base. On the other hand, treatment of (C^N^C)AuR (R = Me, aryl, alkynyl) with thiols under similar conditions leads to selective C-C rather than C-S bond formation. The reaction of (C^N^C)AuSAd with H+ in the absence of a donor ligand affords the thiolato-bridged complex [{(C^N-CH)Au(μ-SAd)}2]2+ which was crystallographically characterised.

  5. The C-S-H gel of Portland cement mortars: Part I. The interpretation of energy-dispersive X-ray microanalyses from scanning electron microscopy, with some observations on C-S-H, AFm and AFt phase compositions

    International Nuclear Information System (INIS)

    Famy, C.; Brough, A.R.; Taylor, H.F.W.

    2003-01-01

    Scanning electron microscopy (SEM) microanalyses of the calcium-silicate-hydrate (C-S-H) gel in Portland cement pastes rarely represent single phases. Essential experimental requirements are summarised and new procedures for interpreting the data are described. These include, notably, plots of Si/Ca against other atom ratios, 3D plots to allow three such ratios to be correlated and solution of linear simultaneous equations to test and quantify hypotheses regarding the phases contributing to individual microanalyses. Application of these methods to the C-S-H gel of a 1-day-old mortar identified a phase with Al/Ca=0.67 and S/Ca=0.33, which we consider to be a highly substituted ettringite of probable composition C 6 A 2 S-bar 2 H 34 or {Ca 6 [Al(OH) 6 ] 2 ·24H 2 O}(SO 4 ) 2 [Al(OH) 4 ] 2 . If this is true for Portland cements in general, it might explain observed discrepancies between observed and calculated aluminate concentrations in the pore solution. The C-S-H gel of a similar mortar aged 600 days contained unsubstituted ettringite and an AFm phase with S/Ca=0.125

  6. Roll bonding of strained aluminium

    DEFF Research Database (Denmark)

    Staun, Jakob M.

    2003-01-01

    This report investigates roll bonding of pre-strained (å ~ 4) aluminium sheets to produce high strain material from high purity aluminium (99.996%) and commercial pure aluminium (99.6%). The degree of bonding is investigated by optical microscopy and ultrasonic scanning. Under the right...... of the cross rolled volume fraction is found. To further asses this effect, and the anisotropy, it is necessary to acquire knowledge about both texture and microstructure, e.g. by TEM. Roll bonding of pre-strained aluminium is found to be a possible alternative to ARB in the quest for ultra-fine grained...

  7. Direct Bonded Pontic (Laporan Kasus

    Directory of Open Access Journals (Sweden)

    Suhandi Sidjaja

    2015-10-01

    Full Text Available Advanced science and technology in dentistry enable dental practitioners to modified she bonding techniques in tooth replacement. A pontic made of composite resin bonded to etched enamel of the adjacent teeth can be used in the replacement of one missing anterior tooth with a virgin or sowed adpicent tooth. The advantages of this technique include a one visit treatment, cow cost, good esthetics, less side effects and easy repair or rebounding. Clinical evaluation showed a high success rate therefore with a proper diagnosis and a perfect skill of the direct bonded technique this treatment can be used as an alternative restoration.

  8. Search for the Pentaquark via the Decay $P^0_{\\bar{c}s} \\to \\phi \\pi \\rho$

    Energy Technology Data Exchange (ETDEWEB)

    Beck, S.Maytal [Tel Aviv U.

    1998-01-01

    This work reports results of the first search for the pentaquark, which is predicted to be a doublet of states: $P^0_{\\bar{c}s} = \\mid \\bar{c}suud$ > and $P^-_{\\bar{c}s}$ = $\\mid \\bar{c}sddu>$. The color hyperfine interaction between their constituent quarks results in a maximal binding potential of 150 MeV. Calculations done using other models predict that the pentaquark is either bound or is a near-threshold resonance. A bound pentaquark would have a mass below 2.907 GeV /$c^2$ and its lifetime would be like that of other charm particles, of the order of $10^{-13}$ s. Crude estimates of the pentaquark production cross section predict values of the order of 1 % of that of the $D_s$. Observation of the pentaquark is interesting for its unusual structure and would contribute to the understanding of QCD and the concept of confinement....

  9. dimensional architectures via hydrogen bonds

    Indian Academy of Sciences (India)

    Administrator

    organization and has potential applications in the field of magnetism ... The concepts of crystal engineering ... 4. However, the utilization of hydrogen bond supramolecular syn- ... sembling the coordination networks by designing the ligands ...

  10. Hydrogen bonding in tight environments

    DEFF Research Database (Denmark)

    Pirrotta, Alessandro; Solomon, Gemma C.; Franco, Ignacio

    2016-01-01

    The single-molecule force spectroscopy of a prototypical class of hydrogen-bonded complexes is computationally investigated. The complexes consist of derivatives of a barbituric acid and a Hamilton receptor that can form up to six simultaneous hydrogen bonds. The force-extension (F-L) isotherms...... of the host-guest complexes are simulated using classical molecular dynamics and the MM3 force field, for which a refined set of hydrogen bond parameters was developed from MP2 ab initio computations. The F-L curves exhibit peaks that signal conformational changes during elongation, the most prominent...... of which is in the 60-180 pN range and corresponds to the force required to break the hydrogen bonds. These peaks in the F-L curves are shown to be sensitive to relatively small changes in the chemical structure of the host molecule. Thermodynamic insights into the supramolecular assembly were obtained...

  11. Adhesives for orthodontic bracket bonding

    Directory of Open Access Journals (Sweden)

    Déborah Daniella Diniz Fonseca

    2010-04-01

    Full Text Available The advent of acid etching, introduced by Buonocore in 1955, brought the possibility of bonding between the bracket base and enamel, contributing to more esthetic and conservative orthodontics. This direct bracket bonding technique has brought benefits such as reduced cost and time in performing the treatment, as well as making it easier to perform oral hygiene. The aim of this study was to conduct a survey of published studies on orthodontic bracket bonding to dental enamel. It was verified that resin composites and glass ionomer are the most studied and researched materials for this purpose. Resin-modified glass ionomer, with its biocompatibility, capacity of releasing fluoride and no need for acid etching on the tooth structure, has become increasingly popular among dentists. However, due to the esthetic and mechanical properties of light polymerizable resin composite, it continues to be one of the adhesives of choice in the bracket bonding technique and its use is widely disseminated.

  12. Method to improve commercial bonded SOI material

    Science.gov (United States)

    Maris, Humphrey John; Sadana, Devendra Kumar

    2000-07-11

    A method of improving the bonding characteristics of a previously bonded silicon on insulator (SOI) structure is provided. The improvement in the bonding characteristics is achieved in the present invention by, optionally, forming an oxide cap layer on the silicon surface of the bonded SOI structure and then annealing either the uncapped or oxide capped structure in a slightly oxidizing ambient at temperatures greater than 1200.degree. C. Also provided herein is a method for detecting the bonding characteristics of previously bonded SOI structures. According to this aspect of the present invention, a pico-second laser pulse technique is employed to determine the bonding imperfections of previously bonded SOI structures.

  13. Comparative evaluation of shear bond strength of metallic brackets bonded with two different bonding agents under dry conditions and with saliva contamination

    Directory of Open Access Journals (Sweden)

    Mashallah Khanehmasjedi

    2017-02-01

    Conclusion: Application of Single Bond and Assure bonding agents resulted in adequate bond strength of brackets to tooth structures. Contamination with saliva significantly decreased the bond strength of Assure bonding agent compared with dry conditions.

  14. Proposal of new bonding technique 'Instantaneous Liquid Phase (ILP) Bonding'

    International Nuclear Information System (INIS)

    Zhang, Yue-Chang; Nakagawa, Hiroji; Matsuda, Fukuhisa.

    1987-01-01

    A new bonding technique named ''Instantaneous Liquid Phase (ILP) bonding'' suitable mainly for welding dissimilar materials was proposed by which instantaneous melting of one or two of the faying surfaces is utilized. The processes of ILP bonding are mainly consisted of three stages, namely the first stage forming thin liquid layer by rapid heating, the second stage joining both specimens by thin liquid layer, and the third stage cooling the specimens rapidly to avoid the formation of brittle layer. The welding temperatures of the specimens to be welded in ILP bonding are generally differentiated from each other. ILP bonding was applied for a variety of combinations of dissimilar materials of aluminum, aluminum alloys, titanium, titanium alloy, carbon steel, austenitic stainless steel, copper and tungsten, and for similar materials of stainless steel and nickel-base alloy. There were no microvoids in these welding joints, and the formation of brittle layer at the bonding interface was suppressed. The welded joints of Al + Ti, Cu + carbon steel and Cu + austenitic stainless steel showed the fracture in base metal having lower tensile strength. Further, the welded joints of Al + carbon steel, Al alloy + Ti, Al alloy + carbon steel or + austenitic stainless steel, Ti + carbon steel or + austenitic stainless steel showed better tensile properties in the comparison with diffusion welding. Furthermore, ILP bonding was available for welding same materials susceptible to hot cracking. Because of the existence of liquid layer, the welding pressure required was extremely low, and preparation of faying surface by simple tooling or polishing by no.80 emery paper was enough. The change in specimen length before and after welding was relatively little, only depending on the thickness of liquid layer. The welding time was very short, and thus high welding efficiency was obtained. (author)

  15. Shear Bond Strength of Orthodontic Brackets Bonded to Zirconium Crowns.

    Science.gov (United States)

    Mehmeti, Blerim; Azizi, Bleron; Kelmendi, Jeta; Iljazi-Shahiqi, Donika; Alar, Željko; Anić-Milošević, Sandra

    2017-06-01

    An increasing demand for esthetic restorations has resulted in an increased use of all-ceramic restorations, such as zirconium. However, one of the challenges the orthodontist must be willing to face is how to increase bond strength between the brackets and various ceramic restorations.Bond strength can beaffected bybracket type, by the material that bracketsaremade of, and their base surface design or retention mode. ​: A im: of this study was to perform a comparative analysis of the shear bond strength (SBS) of metallic and ceramic orthodontic brackets bonded to all-zirconium ceramic surfaces used for prosthetic restorations, and also to evaluate the fracture mode of these two types of orthodontic brackets. Twenty samples/semi-crowns of all-zirconium ceramic, on which orthodontic brackets were bonded, 10 metallic and 10 ceramic polycrystalline brackets, were prepared for this research. SBS has been testedby Universal Testing Machine, with a load applied using a knife edged rod moving at a fixed rate of 1 mm/min, until failure occurred. The force required to debond the brackets was recorded in Newton, then SBS was calculated to MPa. In addition, the samples were analyzed using a digital camera magnifier to determine Adhesive Remnant Index (ARI). Statistical data were processed using t-test, and the level of significance was set at α = 0.05. Higher shear bond strength values were observed in metallic brackets bonded to zirconium crowns compared tothoseof ceramic brackets, with a significant difference. During the test, two of the ceramic brackets were partially or totally damaged. Metallic brackets, compared to ceramic polycrystalline brackets, seemed tocreate stronger adhesion with all-zirconium surfaces due to their better retention mode. Also, ceramic brackets showed higher fragility during debonding.

  16. Characterization of the Bonds Developed between Calcium Silicate Hydrate and Polycarboxylate-Based Superplasticizers with Silyl Functionalities.

    Science.gov (United States)

    Orozco, Carlos A; Chun, Byong W; Geng, Guoqing; Emwas, Abdul H; Monteiro, Paulo J M

    2017-04-11

    Major developments in concrete technology have been achieved with the use of polycarboxylate-based superplasticizers (PCEs) to improve the concrete rheology without increasing the mix water content. Currently, it is possible to control the fluidity of the fresh concrete and obtain stronger and more durable structures. Therefore, there is a strong incentive to understand the interactions between PCEs and cement hydrates at the atomic scale to design new customized functional PCEs according to the ever-increasing requirements of the concrete industry. Here, the bonding types generated between a PCE with silyl functionalities (PCE-Sil) and a synthetic calcium silicate hydrate (C-S-H) are analyzed using XRD, 29 Si NMR spectroscopy, and synchrotron-based techniques, such as NEXAFS and EXAFS. The results indicated that the carboxylic groups present in PCE-Sil interact by a ligand-type bond with calcium, which modified not only the symmetry and coordination number of the calcium located at the surface of C-S-H but also the neighboring silicon atoms of the C-S-H. In addition, the silyl functionalities of the PCE-Sil generated covalent bonds through siloxane bridges between the silanol groups of PCE-Sil and the nonbonding oxygen located at the dimeric sites in C-S-H, forming new bridging silicon sites and subsequently increasing the silicate polymerization.

  17. Characterization of the Bonds Developed between Calcium Silicate Hydrate and Polycarboxylate-Based Superplasticizers with Silyl Functionalities

    KAUST Repository

    Orozco, Carlos A.; Chun, Byong W.; Geng, Guoqing; Emwas, Abdul-Hamid M.; Monteiro, Paulo J. M.

    2017-01-01

    Major developments in concrete technology have been achieved with the use of polycarboxylate-based superplasticizers (PCEs) to improve the concrete rheology without increasing the mix water content. Currently, it is possible to control the fluidity of the fresh concrete and obtain stronger and more durable structures. Therefore, there is a strong incentive to understand the interactions between PCEs and cement hydrates at the atomic scale to design new customized functional PCEs according to the ever-increasing requirements of the concrete industry. Here, the bonding types generated between a PCE with silyl functionalities (PCE-Sil) and a synthetic calcium silicate hydrate (C-S-H) are analyzed using XRD, 29Si NMR spectroscopy, and synchrotron-based techniques, such as NEXAFS and EXAFS. The results indicated that the carboxylic groups present in PCE-Sil interact by a ligand-type bond with calcium, which modified not only the symmetry and coordination number of the calcium located at the surface of C-S-H but also the neighboring silicon atoms of the C-S-H. In addition, the silyl functionalities of the PCE-Sil generated covalent bonds through siloxane bridges between the silanol groups of PCE-Sil and the nonbonding oxygen located at the dimeric sites in C-S-H, forming new bridging silicon sites and subsequently increasing the silicate polymerization.

  18. Characterization of the Bonds Developed between Calcium Silicate Hydrate and Polycarboxylate-Based Superplasticizers with Silyl Functionalities

    KAUST Repository

    Orozco, Carlos A.

    2017-03-24

    Major developments in concrete technology have been achieved with the use of polycarboxylate-based superplasticizers (PCEs) to improve the concrete rheology without increasing the mix water content. Currently, it is possible to control the fluidity of the fresh concrete and obtain stronger and more durable structures. Therefore, there is a strong incentive to understand the interactions between PCEs and cement hydrates at the atomic scale to design new customized functional PCEs according to the ever-increasing requirements of the concrete industry. Here, the bonding types generated between a PCE with silyl functionalities (PCE-Sil) and a synthetic calcium silicate hydrate (C-S-H) are analyzed using XRD, 29Si NMR spectroscopy, and synchrotron-based techniques, such as NEXAFS and EXAFS. The results indicated that the carboxylic groups present in PCE-Sil interact by a ligand-type bond with calcium, which modified not only the symmetry and coordination number of the calcium located at the surface of C-S-H but also the neighboring silicon atoms of the C-S-H. In addition, the silyl functionalities of the PCE-Sil generated covalent bonds through siloxane bridges between the silanol groups of PCE-Sil and the nonbonding oxygen located at the dimeric sites in C-S-H, forming new bridging silicon sites and subsequently increasing the silicate polymerization.

  19. Voltage-assisted polymer wafer bonding

    International Nuclear Information System (INIS)

    Varsanik, J S; Bernstein, J J

    2012-01-01

    Polymer wafer bonding is a widely used process for fabrication of microfluidic devices. However, best practices for polymer bonds do not achieve sufficient bond strength for many applications. By applying a voltage to a polymer bond in a process called voltage-assisted bonding, bond strength is shown to improve dramatically for two polymers (Cytop™ and poly(methyl methacrylate)). Several experiments were performed to provide a starting point for further exploration of this technique. An optimal voltage range is experimentally observed with a reduction in bonding strength at higher voltages. Additionally, voltage-assisted bonding is shown to reduce void diameter due to bond defects. An electrostatic force model is proposed to explain the improved bond characteristics. This process can be used to improve bond strength for most polymers. (paper)

  20. Optimising hydrogen bonding in solid wood

    DEFF Research Database (Denmark)

    Engelund, Emil Tang

    2009-01-01

    The chemical bonds of wood are both covalent bonds within the wood polymers and hydrogen bonds within and between the polymers. Both types of bonds are responsible for the coherence, strength and stiffness of the material. The hydrogen bonds are more easily modified by changes in load, moisture...... and temperature distorting the internal bonding state. A problem arises when studying hydrogen bonding in wood since matched wood specimens of the same species will have very different internal bonding states. Thus, possible changes in the bonding state due to some applied treatment such as conditioning...... maintaining 100 % moisture content of the wood. The hypothesis was that this would enable a fast stress relaxation as a result of reorganization of bonds, since moisture plasticizes the material and temperature promotes faster kinetics. Hereby, all past bond distortions caused by various moisture, temperature...

  1. "Vibrational bonding": a new type of chemical bond is discovered.

    Science.gov (United States)

    Rhodes, Christopher J; Macrae, Roderick M

    2015-01-01

    A long-sought but elusive new type of chemical bond, occurring on a minimum-free, purely repulsive potential energy surface, has recently been convincingly shown to be possible on the basis of high-level quantum-chemical calculations. This type of bond, termed a vibrational bond, forms because the total energy, including the dynamical energy of the nuclei, is lower than the total energy of the dissociated products, including their vibrational zero-point energy. For this to be the case, the ZPE of the product molecule must be very high, which is ensured by replacing a conventional hydrogen atom with its light isotope muonium (Mu, mass = 1/9 u) in the system Br-H-Br, a natural transition state in the reaction between Br and HBr. A paramagnetic species observed in the reaction Mu +Br2 has been proposed as a first experimental sighting of this species, but definitive identification remains challenging.

  2. Enamel Bond Strength of New Universal Adhesive Bonding Agents.

    Science.gov (United States)

    McLean, D E; Meyers, E J; Guillory, V L; Vandewalle, K S

    2015-01-01

    Universal bonding agents have been introduced for use as self-etch or etch-and-rinse adhesives depending on the dental substrate and clinician's preference. The purpose of this study was to evaluate the shear bond strength (SBS) of composite to enamel using universal adhesives compared to a self-etch adhesive when applied in self-etch and etch-and-rinse modes over time. Extracted human third molars were used to create 120 enamel specimens. The specimens were ground flat and randomly divided into three groups: two universal adhesives and one self-etch adhesive. Each group was then subdivided, with half the specimens bonded in self-etch mode and half in etch-and-rinse mode. The adhesives were applied as per manufacturers' instructions, and composite was bonded using a standardized mold and cured incrementally. The groups were further divided into two subgroups with 10 specimens each. One subgroup was stored for 24 hours and the second for six months in 37°C distilled water and tested in shear. Failure mode was also determined for each specimen. A three-way analysis of variance (ANOVA) found a significant difference between groups based on bonding agent (p0.05). Clearfil SE in etch-and-rinse and self-etch modes had more mixed fractures than either universal adhesive in either mode. Etching enamel significantly increased the SBS of composite to enamel. Clearfil SE had significantly greater bond strength to enamel than either universal adhesive, which were not significantly different from each other.

  3. Common Factors in International Bond Returns

    NARCIS (Netherlands)

    Driessen, J.J.A.G.; Melenberg, B.; Nijman, T.E.

    2000-01-01

    In this paper we estimate and interpret the factors that jointly determine bond returns of different maturities in the US, Germany and Japan.We analyze both currency-hedged and unhedged bond returns.For currency-hedged bond returns, we find that five factors explain 96.5% of the variation of bond

  4. 7 CFR 1726.27 - Contractor's bonds.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false Contractor's bonds. 1726.27 Section 1726.27... AGRICULTURE ELECTRIC SYSTEM CONSTRUCTION POLICIES AND PROCEDURES General § 1726.27 Contractor's bonds. (a) RUS Form 168b, Contractor's Bond, shall be used when a contractor's bond is required by RUS Forms 200, 257...

  5. Oregon School Bond Manual. Fourth Edition.

    Science.gov (United States)

    Oregon State Dept. of Education, Salem.

    The manual is intended to guide attorneys and officials of school districts in the issuance and sale of school district bonds. Purchasers of school district bonds rely on the recommendations of accredited bond attorneys who render opinions concerning the validity and legality of bond issues offered for sale. This manual is designed to assist in…

  6. Oregon School Bond Manual. Fifth Edition.

    Science.gov (United States)

    Oregon State Dept. of Education, Salem.

    To help school districts comply with Oregon's school bond laws, this manual provides guidelines for school district attorneys and personnel in the issuance and sale of school bonds. The document describes the proper time sequence of the bonding procedure, including elections, school board authorizations, necessary certificates, bond registration…

  7. Deriving the bond pricing equation

    Directory of Open Access Journals (Sweden)

    Kožul Nataša

    2014-01-01

    Full Text Available Given the recent focus on Eurozone debt crisis and the credit rating downgrade not only of US debt, but that of other countries and many UK major banking institutions, this paper aims to explain the concept of bond yield, its different measures and bond pricing equation. Yields on capital market instruments are rarely quoted on the same basis, which makes direct comparison between different as investment choices impossible. Some debt instruments are quoted on discount basis, whilst coupon-bearing ones accrue interest differently, offer different compounding opportunities, have different coupon payment frequencies, and manage non-business day maturity dates differently. Moreover, rules governing debt vary across countries, markets and currencies, making yield calculation and comparison a rather complex issue. Thus, some fundamental concepts applicable to debt instrument yield measurement, with focus on bond equation, are presented here. In addition, bond equation expressed in annuity form and used to apply Newton-Raphson algorithm to derive true bond yield is also shown.

  8. Welding, Bonding and Fastening, 1984

    Science.gov (United States)

    Buckley, J. D. (Editor); Stein, B. A. (Editor)

    1985-01-01

    A compilation of papers presented in a joint NASA, American Society for Metals, The George Washington University, American Welding Soceity, and Society of Manufacturing Engineers conference on Welding, Bonding, and Fastening at Langley Research Center, Hampton, VA, on October 23 to 25, 1984 is given. Papers were presented on technology developed in current research programs relevant to welding, bonding, and fastening of structural materials required in fabricating structures and mechanical systems used in the aerospace, hydrospace, and automotive industries. Topics covered in the conference included equipment, hardware and materials used when welding, brazing, and soldering, mechanical fastening, explosive welding, use of unique selected joining techniques, adhesives bonding, and nondestructive evaluation. A concept of the factory of the future was presented, followed by advanced welding techniques, automated equipment for welding, welding in a cryogenic atmosphere, blind fastening, stress corrosion resistant fasteners, fastening equipment, explosive welding of different configurations and materials, solid-state bonding, electron beam welding, new adhesives, effects of cryogenics on adhesives, and new techniques and equipment for adhesive bonding.

  9. Three methods to measure RH bond energies

    International Nuclear Information System (INIS)

    Berkowitz, J.; Ellison, G.B.; Gutman, D.

    1993-01-01

    In this paper the authors compare and contrast three powerful methods for experimentally measuring bond energies in polyatomic molecules. The methods are: radical kinetics; gas phase acidity cycles; and photoionization mass spectroscopy. The knowledge of the values of bond energies are a basic piece of information to a chemist. Chemical reactions involve the making and breaking of chemical bonds. It has been shown that comparable bonds in polyatomic molecules, compared to the same bonds in radicals, can be significantly different. These bond energies can be measured in terms of bond dissociation energies

  10. Diffusionless bonding of aluminum to Zircaloy-2

    International Nuclear Information System (INIS)

    Watson, R.D.

    1965-04-01

    Aluminum can be bonded to zirconium without difficulty even when a thin layer of oxide is present on the surface of the zirconium . No detectable diffusion takes place during the bonding process. The bond layer can be stretched as much. as 8% without affecting the bond. The bond can be heated for 1000 hours at 260 o C (500 o F), and can be water quenched from 260 o C (500 o F) without any noticeable change in the bond strength. An extrusion technique has been devised for making transition sections of aluminum bonded to zirconium which can then be used to join these metals by conventional welding. Welding can be done close to the bond zone without seriously affecting the integrity of the bond. This method of bonding aluminum to Zircaloy-2 is covered by Canadian patent 702,438 January 26, 1965. (author)

  11. A Definition of the Magnetic Transition Temperature Using Valence Bond Theory.

    Science.gov (United States)

    Jornet-Somoza, Joaquim; Deumal, Mercè; Borge, Juan; Robb, Michael A

    2018-03-01

    Macroscopic magnetic properties are analyzed using Valence Bond theory. Commonly the critical temperature T C for magnetic systems is associated with a maximum in the energy-based heat capacity C p (T). Here a more broadly applicable definition of the magnetic transition temperature T C is described using the spin moment expectation value (i.e., applying the spin exchange density operator) instead of energy. Namely, the magnetic capacity C s (T) reflects variation in the spin multiplicity as a function of temperature, which is shown to be related to ∂[χT(T)]/∂T. Magnetic capacity C s (T) depends on long-range spin interactions that are not relevant in the energy-based heat capacity C p (T). Differences between C s (T) and C p (T) are shown to be due to spin order/disorder within the crystal that can be monitored via a Valence Bond analysis of the corresponding magnetic wave function. Indeed the concept of the Boltzmann spin-alignment order is used to provide information about the spin correlation between magnetic units. As a final illustration, the critical temperature is derived from the magnetic capacity for several molecular magnets presenting different magnetic topologies that have been experimentally studied. A systematic shift between the transition temperatures associated with C s (T) and C p (T) is observed. It is demonstrated that this shift can be attributed to the loss of long-range spin correlation. This suggests that the magnetic capacity C s (T) can be used as a predictive tool for the magnetic topology and thus for the synthetic chemists.

  12. Pricing catastrophic bonds for earthquakes in Mexico

    OpenAIRE

    Cabrera, Brenda López

    2006-01-01

    After the occurrence of a natural disaster, the reconstruction can be financed with catastrophic bonds (CAT bonds) or reinsurance. For insurers, reinsurers and other corporations CAT bonds provide multi year protection without the credit risk present in reinsurance. For investors CAT bonds offer attractive returns and reduction of portfolio risk, since CAT bonds defaults are uncorrelated with defaults of other securities. As the study of natural catastrophe models plays an important role in t...

  13. Two Comments on Bond Angles

    Science.gov (United States)

    Glaister, P.

    1997-09-01

    Tetrahedral Bond Angle from Elementary Trigonometry The alternative approach of using the scalar (or dot) product of vectors enables the determination of the bond angle in a tetrahedral molecule in a simple way. There is, of course, an even more straightforward derivation suitable for students who are unfamiliar with vectors, or products thereof, but who do know some elementary trigonometry. The starting point is the figure showing triangle OAB. The point O is the center of a cube, and A and B are at opposite corners of a face of that cube in which fits a regular tetrahedron. The required bond angle alpha = AÔB; and using Pythagoras' theorem, AB = 2(square root 2) is the diagonal of a face of the cube. Hence from right-angled triangle OEB, tan(alpha/2) = (square root 2) and therefore alpha = 2tan-1(square root 2) is approx. 109° 28' (see Fig. 1).

  14. FATHER, SOCIAL BOND AND WOMEN

    Directory of Open Access Journals (Sweden)

    SYLVIA DE CASTRO KORGI

    2006-05-01

    Full Text Available On the cross-point of two of the most important and inseparable Freudian questions: What is a father?and, What a woman wants?, this paper begins a reflection about the women’s place in the Freudianarticulation of the relationship between the father and the social bond. In fact, the Freudian father, thanksto the law mediation which he is its agent, has as a function the regulation of the pleasure that participatesin the social bond, making this way possible the human community. On the other hand, the support ofthe human community is the bond among brothers, as well as Freud presents it in his foundational textof the Law. How to precise the women’s place in this arrangement? The reflection stands out this thatexceeds the Father’s Law and that Freud sets on women’s account, initially under the figure of heropposition to the culture.

  15. Medieval orality, mothers, and bonding.

    Science.gov (United States)

    Schwartz, Scott C

    2004-01-01

    The role of women in the Middle Ages was vilification, veneration, and exclusion. Due to the high rates of maternal and infant mortality bonding shifted from the mother-child dyad to one in which the Church, Holy Family, and king acted as pseudo-parents. In art this is suggested by the virtual absence of eye contact between the Virgin and Christ-child. Frustration of early oral needs consequent to lack of adequate mother-child bonding prompted a reactive emphasis on orality in art and legend. A decrease in infant mortality and a reciprocal improvement in mother child bonding contributed to cultural shifts in how self-realization would be accomplished during the Renaissance and in the later emergence of secular humanism.

  16. Simultaneous bond degradation and bond formation during phenol-formaldehyde curing with wood

    Science.gov (United States)

    Daniel J. Yelle; John Ralph

    2016-01-01

    Bonding of wood using phenol–formaldehyde adhesive develops highly durable bonds. Phenol– formaldehyde is believed to form primary bonds with wood cell wall polymers (e.g., lignin). However, it is unclear how this adhesive interacts and bonds to lignin. Through wood solubilisation methodologies, earlywood and latewood bonded assemblies were characterized using two-...

  17. Bond Pricing with Default Risk

    OpenAIRE

    Saa-Requejo, Jesus; Santa-Clara, Pedro

    1997-01-01

    We offer a new model for pricing bonds subject to default risk. The event of default is remodeled as the first time that a state variable that captures the solvency of the issue goes below a certain level. The payoff to the bond in case of default is a constant fraction of the value of a security with the same promised payoffs but without the risk of default. We show that our model is very tractable under different models of interest rate risk and of the interaction between default risk and i...

  18. Jane Austen y C. S. Lewis: de la literatura al cine. Análisis de transposición

    Directory of Open Access Journals (Sweden)

    Mercedes Sarapura Sarapura

    2016-11-01

    Full Text Available Esta es una propuesta de análisis de transposición de la literatura al cine de la novela Orgullo y Prejuicio, de Jane Austen, y del ensayo Una pena observada, de C. S. Lewis. El primer propósito en ambos casos es ahondar en los nuevos aportes de la última versión cinematográfica de la novela de Austen, así como en las características y cualidades de la versión fílmica del cuaderno de anotaciones de C. S. Lewis, a partir de las contribuciones teóricas de autores como Gerard Genette, Georffrey Wagner, Brian Mcfarlane, entre otros. El segundo objetivo se orienta al reconocimiento del intercambio entre el lenguaje cinematográfico y literario como un proceso representativo de la sociedad actual. El hecho de que las adaptaciones (históricamente vistas con gran escepticismo sean ahora continuamente realizadas y acogidas por el público, insta a una revisión y profundización de los estudios que se han hecho al respecto con el fin de conocer la situación actual de la relación existente entre cine y literatura, sus posibilidades creativas, las expectativas de las audiencias, los prejuicios y recelos de los expertos, etc.

  19. Catalytic diastereoselective tandem conjugate addition-elimination reaction of Morita-Baylis-Hillman C adducts by C-C bond cleavage

    KAUST Repository

    Yang, Wenguo; Tan, Davin; Lee, Richmond; Li, Lixin; Pan, Yuanhang; Huang, Kuo-Wei; Tan, Choonhong; Jiang, Zhiyong

    2012-01-01

    Through the cleavage of the C-C bond, the first catalytic tandem conjugate addition-elimination reaction of Morita-Baylis-Hillman C adducts has been presented. Various S N2′-like C-, S-, and P-allylic compounds could be obtained with exclusive E

  20. Reaction-bonded silicon nitride

    International Nuclear Information System (INIS)

    Porz, F.

    1982-10-01

    Reaction-bonded silicon nitride (RBSN) has been characterized. The oxidation behaviour in air up to 1500 0 C and 3000 h and the effects of static and cyclic oxidation on room-temperature strength have been studied. (orig./IHOE) [de

  1. Breaking Rules – Making Bonds

    Indian Academy of Sciences (India)

    IAS Admin

    unusual because it has a pair of non-bonding electrons. So we would classify it ... you would expect the boron to be electron rich with a formal oxidation state of ... Principles of Structure and Reactivity, 4th Edition, Pearson Education, 2008. [3].

  2. Essays on European bond markets

    NARCIS (Netherlands)

    Cheung, Y.C.

    2005-01-01

    This dissertation focused on a number of issues that are of importance in the current European bond market. In the past years, the fiscal policy of the Eurozone members, advances in the technology of trading platforms and the introduction of a single currency have reshaped the fixed income markets

  3. Analysis of Disulfide Bond Formation

    NARCIS (Netherlands)

    Braakman, Ineke; Lamriben, Lydia; van Zadelhoff, Guus; Hebert, Daniel N.

    2017-01-01

    In this unit, protocols are provided for detection of disulfide bond formation in cultures of intact cells and in an in vitro translation system containing isolated microsomes or semi-permeabilized cells. First, the newly synthesized protein of interest is biosynthetically labeled with radioactive

  4. [Posterior ceramic bonded partial restorations].

    Science.gov (United States)

    Mainjot, Amélie; Vanheusden, Alain

    2006-01-01

    Posterior ceramic bonded partial restorations are conservative and esthetic approaches for compromised teeth. Overlays constitute a less invasive alternative for tooth tissues than crown preparations. With inlays and onlays they are also indicated in case of full arch or quadrant rehabilitations including several teeth. This article screens indications and realization of this type of restorations.

  5. Adhesive bonding of wood materials

    Science.gov (United States)

    Charles B. Vick

    1999-01-01

    Adhesive bonding of wood components has played an essential role in the development and growth of the forest products industry and has been a key factor in the efficient utilization of our timber resource. The largest use of adhesives is in the construction industry. By far, the largest amounts of adhesives are used to manufacture building materials, such as plywood,...

  6. Strength of Bond Covenants and Bond Assessment Framework

    Directory of Open Access Journals (Sweden)

    Noel Yahanpath

    2012-06-01

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

  7. ASM Triggered too Observations of 100,000 C/s Black-Hole Candidates (core Program)

    Science.gov (United States)

    Resubmission accepted Cycle 2-11 proposal. The PCA is unique by the high count rates (~100.000 c/s) it can record, and its resulting extreme sensitivity to weak variability. Only few sources get this bright. Our RXTE work on Sco X-1 and 1744-28 shows that high count rate observations are very rewarding, but also difficult and not without risk. In the life of the satellite probably only one black hole transient (if any) will reach 10^5 cps/5 PCU levels. When this occurs a window of discovery will be opened on black holes, which will nearly certainly close again within a few days. This proposal aims at ensuring that optimal use is made of this opportunity by performing state of the art high count rate observations covering all of the most crusial aspects of the source variability.

  8. Important contributions of M.C. Wang and C.S. Wang Chang to non-equilibrium statistical physics

    International Nuclear Information System (INIS)

    Liu Jixing

    2004-01-01

    In the middle of the 20th century two Chinese women physicists, Ming-Chen Wang and Cheng-Shu Wang Chang made great contributions to statistical physics. The famous review article 'On the theory of the Brownian motion II' by Ming-Chen Wang and G.E. Uhlenbeck published in Rev. of Mod. Phys. in 1945 provided a complete scientific classification of stochastic processes which is still adopted by the scientific community as the standard classification. The Wang-Chang-Uhlenbeck (WCU) equation proposed jointly by C.S. Wang-Chang and Uhlenbeck became the fundamental kinetic equation for the treatment of transport properties of multi-atomic gases with internal degrees of freedom in the physics literature. These important scientific contributions are analyzed and reviewed

  9. Thermo-hydraulic-mechanical analysis of the SS-050 sodium loop during a thermal shock of 2000C/s

    International Nuclear Information System (INIS)

    Jesus Miranda, C.A. de; Gebrin, A.N.

    1988-01-01

    An analytical thermo-hydraulic model was developed to obtain the temperature of the sodium flowing between the mixing tank TM of constant volume and the drain tank of the SS-050 sodium test facility. The piping connecting these two tanks is considered in the analysis. The sodium enters in the TM through a tube with lateral holes immersed in the TM's sodium. The model and relative computer program were tested and a typical situation was studied: a thermal shock with -200 0 C/s of thermal gradient in the test section. The sodium temperature time-histories along the piping length are presented. For the thermal shock situation, the temperature field in the TM bottom and outlet nozzle was calculated and the stresses were evaluated. The final thermal stresses will allow a detailed verification of the circuit design. (author) [pt

  10. Lithium Sulfur Primary Battery with Super High Energy Density: Based on the Cauliflower-like Structured C/S Cathode

    Science.gov (United States)

    Ma, Yiwen; Zhang, Hongzhang; Wu, Baoshan; Wang, Meiri; Li, Xianfeng; Zhang, Huamin

    2015-10-01

    The lithium-sulfur primary batteries, as seldom reported in the previous literatures, were developed in this work. In order to maximize its practical energy density, a novel cauliflower-like hierarchical porous C/S cathode was designed, for facilitating the lithium-ions transport and sulfur accommodation. This kind of cathode could release about 1300 mAh g-1 (S) capacity at sulfur loading of 6 ~ 14 mg cm-2, and showed excellent shelf stability during a month test at room temperature. As a result, the assembled Li-S soft package battery achieved an energy density of 504 Wh kg-1 (654 Wh L-1), which was the highest value ever reported to the best of our knowledge. This work might arouse the interests on developing primary Li-S batteries, with great potential for practical application.

  11. Cement hydration from hours to centuries controlled by diffusion through barrier shells of C-S-H

    Science.gov (United States)

    Rahimi-Aghdam, Saeed; Bažant, Zdeněk P.; Abdolhosseini Qomi, M. J.

    2017-02-01

    Although a few good models for cement hydration exist, they have some limitations. Some do not take into account the complete range of variation of pore relative humidity and temperature, and apply over durations limited from up a few months to up to about a year. The ones that are applicable for long durations are either computationally too intensive for use in finite element programs or predict the hydration to terminate after few months. However, recent tests of autogenous shrinkage and swelling in water imply that the hydration may continue, at decaying rate, for decades, provided that a not too low relative pore humidity (above 0.7) persists for a long time, as expected for the cores of thick concrete structural members. Therefore, and because design lifetimes of over hundred years are required for large concrete structures, a new hydration model for a hundred year lifespan and beyond is developed. The new model considers that, after the first day of hydration, the remnants of anhydrous cement grains, gradually consumed by hydration, are enveloped by contiguous, gradually thickening, spherical barrier shells of calcium-silicate hydrate (C-S-H). The hydration progress is controlled by transport of water from capillary pores through the barrier shells toward the interface with anhydrous cement. The transport is driven by a difference of humidity, defined by equivalence with the difference in chemical potential of water. Although, during the period of 4-24 h, the C-S-H forms discontinuous nano-globules around the cement grain, an equivalent barrier shell control was formulated for this period, too, for ease and effectiveness of calculation. The entire model is calibrated and validated by published test data on the evolution of hydration degree for various cement types, particle size distributions, water-cement ratios and temperatures. Computationally, this model is sufficiently effective for calculating the evolution of hydration degree (or aging) at every

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

    DEFF Research Database (Denmark)

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

    2010-01-01

    of the mixed phase at metal surfaces. The surface bonding can be considered to be similar to accepting a hydrogen bond, and we can thereby apply general cooperativity rules developed for hydrogen-bonded systems. This provides a simple understanding of why water molecules become more strongly bonded...... to the surface upon hydrogen bonding to OH and why the OH surface bonding is instead weakened through hydrogen bonding to water. We extend the application of this simple model to other observed cooperativity effects for pure water adsorption systems and H3O+ on metal surfaces.......We examine the balance of surface bonding and hydrogen bonding in the mixed OH + H2O overlayer on Pt(111), Cu(111), and Cu(110) via density functional theory calculations. We find that there is a cooperativity effect between surface bonding and hydrogen bonding that underlies the stability...

  13. The adhesive bonding of beryllium structural components

    International Nuclear Information System (INIS)

    Fullerton-Batten, R.C.

    1977-01-01

    Where service conditions permit, adhesive bonding is a highly recommendable, reliable means of joining beryllium structural parts. Several important programs have successfully used adhesive bonding for joining structural and non-structural beryllium components. Adhesive bonding minimizes stress concentrations associated with other joining techniques and considerably improves fatigue resistance. In addition, no degradation of base metal properties occur. In many instances, structural joints can be fabricated more cheaply by adhesive bonding or in combination with adhesive bonding than by any other method used alone. An evaluation program on structural adhesive bonding of beryllium sheet components is described. A suitable surface pretreatment for beryllium adherends prior to bonding is given. Tensile shear strength and fatigue properties of FM 1000 and FM 123-5 adhesive bonded joints are reviewed and compared with data obtained from riveted joints of similar geometry. (author)

  14. Manufacturing study of beryllium bonded structures

    International Nuclear Information System (INIS)

    Onozuka, M.; Hirai, S.; Kikuchi, K.; Oda, Y.; Shimizu, K.

    2004-01-01

    Manufacturing study has been conducted on Be-bonded structures employed in the first-wall panel of the blanket system for the ITER. For Be tiles bonded to the Cu-Cr-Zr alloy heat sink with stainless-steel cooling pipes, a one-axis hot press with two heating process has been used to bond the three materials. First, Cu-alloy and SS materials are bonded diffusively. Then, Be tiles are bonded to the pre-bonded structure under 20 MPa and at 560 degree C. An Al-Si base interlayer has been used to bond Be to the Cu-Alloy. Because of the limited heat processes using a conventional hot press, the manufacturing cost can be minimized. Using the above bonding techniques, a partial mockup of a blanket first-wall panel with 16 Be tiles (with 50 mm in size) has been successfully manufactured. (author)

  15. Weld bonding of stainless steel

    DEFF Research Database (Denmark)

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

    2004-01-01

    . The overall assessment of the weld bonding process is made using several commercial adhesives with varying working times under different surface conditions. The quality of the resulting joints is evaluated by means of macroetching observations, tension-shear tests and peel tests. The theoretical investigation......This paper presents a comprehensive theoretical and experimental investigation of the weld bonding process with the purpose of evaluating its relative performance in case of joining stainless steel parts, against alternative solutions based on structural adhesives or conventional spot-welding...... of the process consists of numerical predictions based on the commercial finite element program SORPAS with the purpose of establishing the most favourable parameters that allow spot-welding through the adhesives....

  16. Bond graph modeling of centrifugal compression systems

    OpenAIRE

    Uddin, Nur; Gravdahl, Jan Tommy

    2015-01-01

    A novel approach to model unsteady fluid dynamics in a compressor network by using a bond graph is presented. The model is intended in particular for compressor control system development. First, we develop a bond graph model of a single compression system. Bond graph modeling offers a different perspective to previous work by modeling the compression system based on energy flow instead of fluid dynamics. Analyzing the bond graph model explains the energy flow during compressor surge. Two pri...

  17. About counterintuitive orbital mixing and bond populations

    International Nuclear Information System (INIS)

    Jorge, F.E.; Giambiagi, M.; Giambiagi, M.S. de

    1983-01-01

    It is shown that negative bond and orbital populations may be avoided by the introduction of a weight factor in a bond index definition, together with a suitable parameterization. The negative bond populations found for first-row metal complexes need not be ascribed to counterintuitive orbital mixing but rather, essentially, to the equipartition of the charge distribution. Different definitions of the bond population are compared for ferrocene and the effects of some parameterizations are discussed. (Author) [pt

  18. A Cat Bond Premium Puzzle?

    OpenAIRE

    Vivek J. Bantwal; Howard C. Kunreuther

    1999-01-01

    Catastrophe Bonds whose payoffs are tied to the occurrence of natural disasters offer insurers the ability to hedge event risk through the capital markets that could otherwise leave them insolvent if concentrated solely on their own balance sheets. At the same time, they offer investors a unique opportunity to enhance their portfolios with an asset that provides an attractive return that is uncorrelated with typical financial securities Despite its attractiveness, spreads in this market remai...

  19. Copper-mediated C-H activation/C-S cross-coupling of heterocycles with thiols

    KAUST Repository

    Ranjit, Sadananda

    2011-11-04

    We report the synthesis of a series of aryl- or alkyl-substituted 2-mercaptobenzothiazoles by direct thiolation of benzothiazoles with aryl or alkyl thiols via copper-mediated aerobic C-H bond activation in the presence of stoichiometric CuI, 2,2′-bipyridine and Na 2CO 3. We also show that the approach can be extended to thiazole, benzimidazole, and indole substrates. In addition, we present detailed mechanistic investigations on the Cu(I)-mediated direct thiolation reactions. Both computational studies and experimental results reveal that the copper-thiolate complex [(L)Cu(SR)] (L: nitrogen-based bidentate ligand such as 2,2′-bipyridine; R: aryl or alkyl group) is the first reactive intermediate responsible for the observed organic transformation. Furthermore, our computational studies suggest a stepwise reaction mechanism based on a hydrogen atom abstraction pathway, which is more energetically feasible than many other possible pathways including β-hydride elimination, single electron transfer, hydrogen atom transfer, oxidative addition/reductive elimination, and σ-bond metathesis. © 2011 American Chemical Society.

  20. Simple inorganic complexes but intricate hydrogen bonding ...

    Indian Academy of Sciences (India)

    Administrator

    We are interested in obtaining single crystals of metal-opda complexes because their crystal structures would show complex hydrogen bonding network due to the presence of. –NH2 groups in the opda ligand (hydrogen bonding donor sites) and inorganic anions having mostly oxo groups (hydrogen bonding acceptor sites) ...

  1. 75 FR 39730 - Tribal Economic Development Bonds

    Science.gov (United States)

    2010-07-12

    ... DEPARTMENT OF THE TREASURY Tribal Economic Development Bonds AGENCY: Department of the Treasury... (``Treasury'') seeks comments from Indian Tribal Governments regarding the Tribal Economic Development Bond... governments, known as ``Tribal Economic Development Bonds,'' under Section 7871(f) of the Internal Revenue...

  2. 30 CFR 800.21 - Collateral bonds.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Collateral bonds. 800.21 Section 800.21 Mineral... FOR SURFACE COAL MINING AND RECLAMATION OPERATIONS UNDER REGULATORY PROGRAMS § 800.21 Collateral bonds. (a) Collateral bonds, except for letters of credit, cash accounts, and real property, shall be...

  3. Are Stock and Corporate Bond Markets Integrated?

    NARCIS (Netherlands)

    van Zundert, J.; Driessen, Joost

    2017-01-01

    This study explores the cross-sectional integration of stock and corporate bond markets by comparing a firm’s expected stock return, as implied by corporate bond spreads, to its realized stock return. We compute expected corporate bond returns by correcting credit spreads for expected losses due to

  4. 36 CFR 9.48 - Performance bond.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Performance bond. 9.48... MINERALS MANAGEMENT Non-Federal Oil and Gas Rights § 9.48 Performance bond. (a) Prior to approval of a plan of operations, the operator shall be required to file a suitable performance bond with satisfactory...

  5. Environmentally dependent bond-order potentials: New ...

    Indian Academy of Sciences (India)

    Environmentally dependent bond-order potentials: New developments and applications ... for modelling amorphous structure we found that the and bond integrals are not only transferable between graphite and diamond structures but they are also strongly anisotropic due to inter-plan bonding between graphite sheets.

  6. Low temperature anodic bonding to silicon nitride

    DEFF Research Database (Denmark)

    Weichel, Steen; Reus, Roger De; Bouaidat, Salim

    2000-01-01

    Low-temperature anodic bonding to stoichiometric silicon nitride surfaces has been performed in the temperature range from 3508C to 4008C. It is shown that the bonding is improved considerably if the nitride surfaces are either oxidized or exposed to an oxygen plasma prior to the bonding. Both bu...

  7. Liquidity risk premia in corporate bond markets

    NARCIS (Netherlands)

    Driessen, J.J.A.G.; de Jong, F.C.J.M.

    2012-01-01

    This paper explores the role of liquidity risk in the pricing of corporate bonds. We show that corporate bond returns have significant exposures to fluctuations in treasury bond liquidity and equity market liquidity. Further, this liquidity risk is a priced factor for the expected returns on

  8. 25 CFR 216.8 - Performance bond.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Performance bond. 216.8 Section 216.8 Indians BUREAU OF... RECLAMATION OF LANDS General Provisions § 216.8 Performance bond. (a) Upon approval of an exploration plan or mining plan, the operator shall be required to file a suitable performance bond of not less than $2,000...

  9. 43 CFR 23.9 - Performance bond.

    Science.gov (United States)

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Performance bond. 23.9 Section 23.9 Public... LANDS § 23.9 Performance bond. (a)(1) Upon approval of an exploration plan or mining plan, the operator shall be required to file a suitable performance bond of not less than $2,000 with satisfactory surety...

  10. 36 CFR 223.35 - Performance bond.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Performance bond. 223.35 Section 223.35 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE SALE AND... Performance bond. Timber sale contracts may require the purchaser to furnish a performance bond for...

  11. 36 CFR 9.13 - Performance bond.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 1 2010-07-01 2010-07-01 false Performance bond. 9.13... MINERALS MANAGEMENT Mining and Mining Claims § 9.13 Performance bond. (a) Upon approval of a plan of operations the operator shall be required to file a suitable performance bond with satisfactory surety...

  12. 27 CFR 24.146 - Bonds.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Bonds. 24.146 Section 24.146 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE.... (c) Wine vinegar plant bond. The proprietor of a wine vinegar plant who withdraws wine from a bonded...

  13. Practical synthesis of 14C S-ribosyl-L-homocysteine uniformly labelled on the sugar moiety. An enzymatic route from (U-14C) adenosine

    International Nuclear Information System (INIS)

    Guillerm, G.; Allart, B.

    1992-01-01

    [(U- 14 C) S-Ribosyl]-L-homocysteine has been prepared enzymatically from (U- 14 C) adenosine in two steps using S-adenosyl homocysteine hydrolase and bacterial S-adenosyl homocysteine nucleosidase as catalysts. (Author)

  14. Recent Advances in Adhesive Bonding - The Role of Biomolecules, Nanocompounds, and Bonding Strategies in Enhancing Resin Bonding to Dental Substrates.

    Science.gov (United States)

    Münchow, Eliseu A; Bottino, Marco C

    2017-09-01

    To present an overview on the main agents (i.e., biomolecules and nanocompounds) and/or strategies currently available to amplify or stabilize resin-dentin bonding. According to studies retrieved for full text reading (2014-2017), there are currently six major strategies available to overcome resin-dentin bond degradation: (i) use of collagen crosslinking agents, which may form stable covalent bonds with collagen fibrils, thus strengthening the hybrid layer; (ii) use of antioxidants, which may allow further polymerization reactions over time; (iii) use of protease inhibitors, which may inhibit or inactivate metalloproteinases; (iv) modification of the bonding procedure, which may be performed by using the ethanol wet-bonding technique or by applying an additional adhesive (hydrophobic) coating, thereby strengthening the hybrid layer; (v) laser treatment of the substrate prior to bonding, which may cause specific topographic changes in the surface of dental substrates, increasing bonding efficacy; and (vi) reinforcement of the resin matrix with inorganic fillers and/or remineralizing agents, which may positively enhance physico-mechanical properties of the hybrid layer. With the present review, we contributed to the better understanding of adhesion concepts and mechanisms of resin-dentin bond degradation, showing the current prospects available to solve that problematic. Also, adhesively-bonded restorations may be benefited by the use of some biomolecules, nanocompounds or alternative bonding strategies in order to minimize bond strength degradation.

  15. Live Cell Imaging Reveals Differential Modifications to Cytoplasmic Dynein Properties by Phospho- and Dephospho-mimic Mutations of the Intermediate Chain 2C S84

    Science.gov (United States)

    Blasier, Kiev R.; Humsi, Michael K.; Ha, Junghoon; Ross, Mitchell W.; Smiley, W. Russell; Inamdar, Nirja A.; Mitchell, David J.; Lo, Kevin W.-H.; Pfister, K. Kevin

    2014-01-01

    Cytoplasmic dynein is a multi-subunit motor protein responsible for intracellular cargo transport toward microtubule minus ends. There are multiple isoforms of the dynein intermediate chain (DYNC1I, IC) which is encoded by two genes. One way to regulate cytoplasmic dynein is by IC phosphorylation. The IC-2C isoform is expressed in all cells and the functional significance of phosphorylation on IC-2C serine 84 was investigated using live cell imaging of fluorescent protein-tagged wild type IC-2C (WT) and phospho- and dephospho-mimic mutant isoforms in axonal transport model systems. Both mutations modulated dynein functional properties. The dephospho-mimic mutant IC-2C S84A had greater co-localization with mitochondria than IC-2C wild-type (WT) or the phospho-mimic mutant IC-2C S84D. The dephospho-mimic mutant IC-2C S84A was also more likely to be motile than the phospho-mimic mutant IC-2C S84D or IC-2C WT. In contrast, the phospho-mimic mutant IC-2C S84D mutant was more likely to move in the retrograde direction than was the IC-2C S84A mutant. The phospho-mimic IC-2C S84D was also as likely as IC-2C WT to co-localize with mitochondria. Both the S84D phospho- and S84A, dephospho-mimic mutants were found to be capable of microtubule minus end directed (retrograde) movement in axons. They were also observed to be passively transported in the anterograde direction. These data suggest that the IC-2C S84 has a role in modulating dynein properties. PMID:24798412

  16. Strength of Al and Al-Mg/alumina bonds prepared using ultrahigh vacuum diffusion bonding

    International Nuclear Information System (INIS)

    King, W.E.; Campbell, G.H.; Wien, W.L.; Stoner, S.L.

    1994-01-01

    The authors have measured the cross-breaking strength of Al and Al-Mg alloys bonded with alumina. Diffusion bonding of Al and Al-Mg alloys requires significantly more bonding time than previously thought to obtain complete bonding. In contrast to previous diffusion bonding studies, fracture morphologies are similar to those obtained in bonds formed by liquid phase reaction; i.e., bonds are as strong or stronger than the ceramic; and fracture tends to propagate in the metal for pure Al and near the interface in the ceramic for the alloys. There are indications that the fracture morphology depends on Mg content and therefore on plasticity in the metal

  17. Effect of ethanol-wet-bonding technique on resin–enamel bonds

    Directory of Open Access Journals (Sweden)

    Muhammet Kerim Ayar

    2014-03-01

    Conclusion: The ethanol-wet-bonding technique may increase the bond strength of commercial adhesives to enamel. The chemical composition of the adhesives can affect the bond strength of adhesives when bonding to acid-etched enamel, using the ethanol-wet-bonding technique. Some adhesive systems used in the present study may simultaneously be applied to enamel and dentin using ethanol-wet-bonding. Furthermore, deploying ethanol-wet-bonding for the tested commercial adhesives to enamel can increase the adhesion abilities of these adhesives to enamel.

  18. Dynamic breaking of a single gold bond

    DEFF Research Database (Denmark)

    Pobelov, Ilya V.; Lauritzen, Kasper Primdal; Yoshida, Koji

    2017-01-01

    While one might assume that the force to break a chemical bond gives a measure of the bond strength, this intuition is misleading. If the force is loaded slowly, thermal fluctuations may break the bond before it is maximally stretched, and the breaking force will be less than the bond can sustain...... of a single Au-Au bond and show that the breaking force is dependent on the loading rate. We probe the temperature and structural dependencies of breaking and suggest that the paradox can be explained by fast breaking of atomic wires and slow breaking of point contacts giving very similar breaking forces....

  19. Hexacoordinate bonding and aromaticity in silicon phthalocyanine.

    Science.gov (United States)

    Yang, Yang

    2010-12-23

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

  20. Valuing Convertible Bonds Based on LSRQM Method

    Directory of Open Access Journals (Sweden)

    Jian Liu

    2014-01-01

    Full Text Available Convertible bonds are one of the essential financial products for corporate finance, while the pricing theory is the key problem to the theoretical research of convertible bonds. This paper demonstrates how to price convertible bonds with call and put provisions using Least-Squares Randomized Quasi-Monte Carlo (LSRQM method. We consider the financial market with stochastic interest rates and credit risk and present a detailed description on calculating steps of convertible bonds value. The empirical results show that the model fits well the market prices of convertible bonds in China’s market and the LSRQM method is effective.

  1. Revisiting C.S. Lewis’ Screwtape Letters of 1941 and exploring their relation to ‘Screwtape proposes a toast’

    Directory of Open Access Journals (Sweden)

    Raymond M. Potgieter

    2016-12-01

    Full Text Available According to the Bible, human history unfolds with the overarching presence of God and the limited presence of the devil. Though the fall of humankind into sin resulted in lasting consequences the Judeao-Christian tradition has had little trouble in identifying this distinction. But it is when the devil (and his followers seek to challenge God’s dominion that the role of God becomes sullied through the seeming victories of the devil. C.S. Lewis was signally aware of spiritual warfare. He explored this in many of his writings, but it was especially The Screwtape Letters that fired the imagination of personal spiritual warfare. These were in story-like fashion from the perspective of demons in conversation with one another in the attempt to corrupt, dominate and destroy particular human subjects. The wider applicatory value of these letters is manifested in Lewis’s final letter from Screwtape: it is this letter that addresses the education system and shows how, from the devil’s perspective, matters such as the desensitisation of evil, normalising of forms of violence and deceit all bear evidence of the shifting moral adjustments Lewis identified in the education system of his day. The consequence of this has taken on the semblance of normality so that this normalisation constantly adjusts to the on- going progression towards still weirder and deeper forms of evil.

  2. Liquidity in Government versus Covered Bond Markets

    DEFF Research Database (Denmark)

    Dick-Nielsen, Jens; Gyntelberg, Jacob; Sangill, Thomas

    We present findings on the secondary market liquidity of government and covered bonds in Denmark before, during and after the 2008 financial crisis. The analysis focuses on wholesale trading in the two markets and is based on a complete transaction level dataset covering November 2007 until end...... 2011. Overall, our findings suggest that Danish benchmark covered bonds by and large are as liquid as Danish government bonds - including in periods of market stress. Before the financial crisis of 2008, government bonds were slightly more liquid than covered bonds. During the crisis, trading continued...... in both markets but the government bond market experienced a brief but pronounced decline in market liquidity while liquidity in the covered bond market was more robust - partly reflective of a number of events as well as policy measures introduced in the autumn of 2008. After the crisis, liquidity...

  3. Actor bonds after relationship dissolution

    DEFF Research Database (Denmark)

    Skaates, Maria Anne

    2000-01-01

    Most of the presented papers at the 1st NoRD Workshop can be classified as belonging to the business marketing approach to relationship dissolution. Two papers were conceptual, and the remaining six were empirical studies. The first conceptual study by Skaates (2000) focuses on the nature...... of the actor bonds that remain after a business relationship has ended. The study suggests that an interdisciplinary approach would provide a richer understanding of the phenomenon; this could be achieved by using e.g. Bourdieu's sociological concepts in dissolution research....

  4. The extended variant of the bond valence-bond length correlation curve for boron(III)-oxygen bonds

    International Nuclear Information System (INIS)

    Sidey, Vasyl

    2015-01-01

    The extended variant of the bond valence (s)-bond length (r) correlation curve for boron(III)-oxygen bonds has been closely approximated using the three-parameter function s = [k/(r - l)] - m, where s is measured in valence units (vu), r is measured in Aa, k = 0.53 Aa.vu, l = 0.975(1) Aa and m = 0.32 vu. The function s = exp[(r 0 - r)/b] traditionally used in the modern bond valence model requires the separate set of the bond valence parameters (r 0 = 1.362 Aa; b = 0.23 Aa) in order to approximate the above s-r curve for the bonds shorter than ∝1.3 Aa.

  5. Mechatronic modeling and simulation using bond graphs

    CERN Document Server

    Das, Shuvra

    2009-01-01

    Introduction to Mechatronics and System ModelingWhat Is Mechatronics?What Is a System and Why Model Systems?Mathematical Modeling Techniques Used in PracticeSoftwareBond Graphs: What Are They?Engineering SystemsPortsGeneralized VariablesBond GraphsBasic Components in SystemsA Brief Note about Bond Graph Power DirectionsSummary of Bond Direction RulesDrawing Bond Graphs for Simple Systems: Electrical and MechanicalSimplification Rules for Junction StructureDrawing Bond Graphs for Electrical SystemsDrawing Bond Graphs for Mechanical SystemsCausalityDrawing Bond Graphs for Hydraulic and Electronic Components and SystemsSome Basic Properties and Concepts for FluidsBond Graph Model of Hydraulic SystemsElectronic SystemsDeriving System Equations from Bond GraphsSystem VariablesDeriving System EquationsTackling Differential CausalityAlgebraic LoopsSolution of Model Equations and Their InterpretationZeroth Order SystemsFirst Order SystemsSecond Order SystemTransfer Functions and Frequency ResponsesNumerical Solution ...

  6. Progress in cold roll bonding of metals

    International Nuclear Information System (INIS)

    Li Long; Nagai, Kotobu; Yin Fuxing

    2008-01-01

    Layered composite materials have become an increasingly interesting topic in industrial development. Cold roll bonding (CRB), as a solid phase method of bonding same or different metals by rolling at room temperature, has been widely used in manufacturing large layered composite sheets and foils. In this paper, we provide a brief overview of a technology using layered composite materials produced by CRB and discuss the suitability of this technology in the fabrication of layered composite materials. The effects of process parameters on bonding, mainly including process and surface preparation conditions, have been analyzed. Bonding between two sheets can be realized when deformation reduction reaches a threshold value. However, it is essential to remove surface contamination layers to produce a satisfactory bond in CRB. It has been suggested that the degreasing and then scratch brushing of surfaces create a strong bonding between the layers. Bonding mechanisms, in which the film theory is expressed as the major mechanism in CRB, as well as bonding theoretical models, have also been reviewed. It has also been showed that it is easy for fcc structure metals to bond compared with bcc and hcp structure metals. In addition, hardness on bonding same metals plays an important part in CRB. Applications of composites produced by CRB in industrial fields are briefly reviewed and possible developments of CRB in the future are also described. Corrections were made to the abstract and conclusion of this article on 18 June 2008. The corrected electronic version is identical to the print version. (topical review)

  7. Are PrP(C)s involved in some human myelin diseases? Relating experimental studies to human pathology.

    Science.gov (United States)

    Veber, Daniela; Scalabrino, Giuseppe

    2015-12-15

    We have experimentally demonstrated that cobalamin (Cbl) deficiency increases normal cellular prion (PrP(C)) levels in rat spinal cord (SC) and cerebrospinal fluid (CSF), and decreases PrP(C)-mRNA levels in rat SC. Repeated intracerebroventricular administrations of anti-octapeptide repeat-PrP(C)-region antibodies to Cbl-deficient (Cbl-D) rats prevent SC myelin lesions, and the administrations of PrP(C)s to otherwise normal rats cause SC white matter lesions similar to those induced by Cbl deficiency. Cbl positively regulates SC PrP(C) synthesis in rat by stimulating the local synthesis of epidermal growth factor (EGF), which also induces the local synthesis of PrP(C)-mRNAs, and downregulating the local synthesis of tumor necrosis factor(TNF)-α, thus preventing local PrP(C) overproduction. We have clinically demonstrated that PrP(C) levels are increased in the CSF of patients with subacute combined degeneration (SCD), unchanged in the CSF of patients with Alzheimer's disease and amyotrophic lateral sclerosis, and decreased in the CSF and SC of patients with multiple sclerosis (MS), regardless of its clinical course. We conclude that SCD (human and experimental) is a neurological disease due to excess PrP(C) without conformational change and aggregation, that the increase in PrP(C) levels in SCD and Cbl-D polyneuropathy and their decrease in MS CNS make them antipodian myelin diseases in terms of quantitative PrP(C) abnormalities, and that these abnormalities are related to myelin damage in the former, and impede myelin repair in the latter. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Thermodynamic properties of hydrated cement phases: C-S-H, C-A-S-H and M-S-H

    International Nuclear Information System (INIS)

    Roosz, Cedric

    2016-01-01

    Concrete is one of the most widely used building materials in the world. Durability, mechanical and chemical properties have made it a material of choice in storage concepts proposed by the French National Agency for Radioactive Waste Management (Andra), including the achievement of retaining structures, cell plugs, massive supports or conditioning waste. The study of the stability of the constituent phases of cementitious materials is needed in view of the planned quantities and the durability of the structures, and must consider (i) temperature ranges suitable for cement matrices containment in contact with exothermic waste (25-80 deg. C), and (ii) a representative time scale of the lifetime of the storage. The Andra ThermoChimie project therefore aims to develop a consistent thermodynamic database, to model the chemical evolution of cement materials in the environment of radioactive waste. However, in the present state, the database offers only thermodynamic data of cementitious crystalline phases, as well as a limited data set of three different chemical compositions for nano-crystalline C-S-H. This does not allow to reproduce the degradation of cementitious materials, or model the degradation of the new formulations, such as 'Low pH' concretes. The objective is therefore to acquire a thermodynamic complementary data set on phases such as C-S-H (Calcium Silicate Hydrates) C-A-S-H (Calcium Aluminate Silicate Hydrates) and M-S-H (Magnesium Silicate Hydrates), to complete the ThermoChimie database. This study is based on experimental, analytical and digital work, in order to obtain a set of thermodynamic data (Δ f G 0 , Δ f H 0 , Cp(T), S 0 ) sufficiently representative of the chemical variability of these phases. Finally, this set of data allows the development of a thermodynamic predictive model in extended spaces of compositions and temperatures. Development of this predictive model requires (i) The acquisition of thermodynamic properties on

  9. Textural and mechanical characterization of C-S-H gels from hydration of synthetic T1-C3S, β-C2S and their blends

    Directory of Open Access Journals (Sweden)

    Dolado, J. S.

    2011-06-01

    Full Text Available The textural and mechanical characterization of C-S-H gels formed from the hydration of pure T1-C3S, β-C2S and their blends are studied by Nitrogen sorption and nanoindentation experiments. The surface area and nanoporosity of C-S-H gels formed from the hydration of β-C2S and the 30-70 (T1-C3S and β-C2S mixture are higher than those from hydration of T1-C3S, and 70-30, with the difference decreasing with hydration age. Such changes are well supported by findings of nanoindentation study, which shows the greater relative volume of C-S-H phases with lower densities in the β-C2S and the 30-70 pastes. With the increase in hydration age, the relative volume of C-S-H phases with higher densities increased at the expenses of those with lower density. Important quantitative correlations were found among these textural characteristics and the mean chain length, determined from 29Si magic-angle-spinning (MAS NMR, of the C-S-H gels.La caracterización textural y mecánica de geles C-S-H formados a partir de la hidratación de muestras puras de T1-C3S, ß-C2S y sus mezclas ha sido estudiada por medio de adsorción de nitrógeno y nanoindentación. El área superficial y la nano-porosidad de los geles formados durante la hidratación del ß-C2S y la mezcla 30-70 (T1-C3S- ß-C2S son mayores que los correspondientes a los geles del T1-C3S, y la mezcla 70-30; esta diferencia disminuye con el tiempo de hidratación. Estos cambios coinciden con los resultados de nanoindentación que indican un aumento de volumen relativo de las fases C-S-H con una densidad menor en el caso del ß-C2S y la mezcla 30-70. Al aumentar el tiempo de hidratación, el volumen relativo de fases C-S-H de mayor densidad aumenta a expensas de aquellas de menor densidad. Importantes correlaciones cuantitativas se establecen entre las características texturales y la longitud de cadena media del gel C-S-H, determinada mediante RMN-MAS de 29Si.

  10. Textural and mechanical characterization of C-S-H gels from hydration of synthetic T1-C3S, β-C2S and their blends

    International Nuclear Information System (INIS)

    Goni, S.; Guerrero, A.; Puertas, F.; Hernandez, M. S.; Palacios, M.; Dolado, J. S.; Zhu, W.; Howind, T.

    2011-01-01

    The textural and mechanical characterization of C-S-H gels formed from the hydration of pure T1-C 3 S, β-C 2 S and their blends are studied by Nitrogen sorption and nano indentation experiments. The surface area and nano porosity of C-S-H gels formed from the hydration of β-C 2 S and the 30-70 (T1-C 3 S and β-C 2 S mixture) are higher than those from hydration of T1-C 3 S, and 70-30, with the difference decreasing with hydration age. Such changes are well supported by findings of nano indentation study, which shows the greater relative volume of C-S-H phases with lower densities in the β-C 2 S and the 30-70 pastes. With the increase in hydration age, the relative volume of C-S-H phases with higher densities increased at the expenses of those with lower density. Important quantitative correlations were found among these textural characteristics and the mean chain length, determined from 2 9Si magic-angle-spinning (MAS) NMR, of the C-S-H gels. (Author) 36 refs.

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

    CERN Document Server

    Gilli, Gastone

    2009-01-01

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

  12. DETERMINANTS OF ORI001 TYPE GOVERNMENT BOND

    Directory of Open Access Journals (Sweden)

    Yosandi Yulius

    2011-09-01

    Full Text Available The need to build a strong bond market is amenable, especially after the 1997 crises. This paper analyzes the influence of deposit interest rate, foreign exchange rates, and Composite Stock Price Index on yield-to-maturity of Bond Series Retail ORI001, employing monthly data from Bloomberg information service, 2006(8 to 2008(12, using Generalized Autoregressive Conditional Heteroscedasticity type models. It finds the evidence that deposit interest rate and exchange rate have positive significant influence on the bond, and that stock index has a negative significant influence on the bond. It also finds that Deposit Interest Rate, exchange rate, and the stock index significantly influence the bond altogether.Keywords: Interest rate, exchange rate, composite stock price index, yield-to-maturity, bondJEL classification numbers: G12, G15

  13. Theoretical investigation of compounds with triple bonds

    International Nuclear Information System (INIS)

    Devarajan, Deepa

    2011-01-01

    In this thesis, compounds with potential triple-bonding character involving the heavier main-group elements, Group 4 transition metals, and the actinides uranium and thorium were studied by using molecular quantum mechanics. The triple bonds are described in terms of the individual orbital contributions (σ, π parallel , and π perpendicular to ), involving electron-sharing covalent or donor-acceptor interactions between the orbitals of two atoms or fragments. Energy decomposition, natural bond orbital, and atoms in molecules analyses were used for the bonding analysis of the triple bonds. The results of this thesis suggest that the triple-bonding character between the heavier elements of the periodic table is important and worth further study and exploration.

  14. Generalized bond percolation and statistical mechanics

    International Nuclear Information System (INIS)

    Tsallis, C.

    1978-05-01

    A generalization of traditional bond percolation is performed, in the sens that bonds have now the possibility of partially transmitting the information (a fact which leads to the concept of 'fidelity' of the bond), and also in the sens that, besides the normal tendency to equiprobability, the bonds are allowed to substantially change the information. Furthermore the fidelity is allowed, to become an aleatory variable, and the operational rules concerning the associated distribution laws are determined. Thermally quenched random bonds and the whole body of Statistical Mechanics become particular cases of this formalism, which is in general adapted to the treatment of all problems whose main characteristic is to preserve a part of the information through a long path or array (critical phenomena, regime changements, thermal random models, etc). Operationally it provides a quick method for the calculation of the equivalent probability of complex clusters within the traditional bond percolation problem [pt

  15. Enantioselective functionalization of allylic C-H bonds following a strategy of functionalization and diversification.

    Science.gov (United States)

    Sharma, Ankit; Hartwig, John F

    2013-11-27

    We report the enantioselective functionalization of allylic C-H bonds in terminal alkenes by a strategy involving the installation of a temporary functional group at the terminal carbon atom by C-H bond functionalization, followed by the catalytic diversification of this intermediate with a broad scope of reagents. The method consists of a one-pot sequence of palladium-catalyzed allylic C-H bond oxidation under neutral conditions to form linear allyl benzoates, followed by iridium-catalyzed allylic substitution. This overall transformation forms a variety of chiral products containing a new C-N, C-O, C-S, or C-C bond at the allylic position in good yield with a high branched-to-linear selectivity and excellent enantioselectivity (ee ≤97%). The broad scope of the overall process results from separating the oxidation and functionalization steps; by doing so, the scope of nucleophile encompasses those sensitive to direct oxidative functionalization. The high enantioselectivity of the overall process is achieved by developing an allylic oxidation that occurs without acid to form the linear isomer with high selectivity. These allylic functionalization processes are amenable to an iterative sequence leading to (1,n)-functionalized products with catalyst-controlled diastereo- and enantioselectivity. The utility of the method in the synthesis of biologically active molecules has been demonstrated.

  16. Improving risk allocation through cat bonds

    OpenAIRE

    Nell, Martin; Richter, Andreas

    2002-01-01

    Catastrophe bonds (cat bonds) often use index triggers, such as, for instance, parametric descriptions of a catastrophe. This implies the problem of the so-called basis risk, resulting from the fact that, in contrast to traditional reinsurance, this kind of coverage cannot be a perfect hedge for the primary's insured portfolio. On the other hand, cat bonds offer some very attractive economic features: Besides their usefulness as a solution to the problems of moral hazard and default risk, an ...

  17. Decomposing European bond and equity volatility

    OpenAIRE

    Christiansen, Charlotte

    2004-01-01

    The paper investigates volatility spillover from US and aggregate European asset markets into European national asset markets. A main contribution is that bond and equity volatilities are analyzed simultaneously. A new model belonging to the "volatilityspillover" family is suggested: The conditional variance of e.g. the unexpected German stock return is divided into separate effects from the contemporaneous idiosyncratic variance of US bonds, US stocks, European bonds, European stocks, German...

  18. Halogen bonding in solution: thermodynamics and applications.

    Science.gov (United States)

    Beale, Thomas M; Chudzinski, Michael G; Sarwar, Mohammed G; Taylor, Mark S

    2013-02-21

    Halogen bonds are noncovalent interactions in which covalently bound halogens act as electrophilic species. The utility of halogen bonding for controlling self-assembly in the solid state is evident from a broad spectrum of applications in crystal engineering and materials science. Until recently, it has been less clear whether, and to what extent, halogen bonding could be employed to influence conformation, binding or reactivity in the solution phase. This tutorial review summarizes and interprets solution-phase thermodynamic data for halogen bonding interactions obtained over the past six decades and highlights emerging applications in molecular recognition, medicinal chemistry and catalysis.

  19. Cold pressure welding - the mechanisms governing bonding

    DEFF Research Database (Denmark)

    Bay, Niels

    1979-01-01

    Investigations of the bonding surface in scanning electron microscope after fracture confirm the mechanisms of bond formation in cold pressure welding to be: fracture of work-hardened surface layer, surface expansion increasing the area of virgin surface, extrusion of virgin material through cracks...... of the original surface layer, and establishment of real contact and bonding between virgin material. This implies that normal pressure as well as surface expansion are basic parameters governing the bond strength. Experimental investigations of pressure welding Al-Al under plane strain compression in a specially...

  20. THEORETICAL AND NUMERICAL VALUATION OF CALLABLE BONDS

    OpenAIRE

    Dejun Xie

    2009-01-01

    This paper studies the value of a callable bond and the bond issuer’s optimal financial decision regarding whether to continue the investment on the market or call the bond. Assume the market investment return follows a stochastic model, the value of contract is formulated as a partial differential equation system embedded with a free boundary, defining the level of market return rate at which it is optimal for the issuer to call the bond. A fundamental solution of the partial differential ...

  1. Bonding in ZnSb

    DEFF Research Database (Denmark)

    Bjerg, Lasse; Madsen, Georg K. H.; Iversen, Bo Brummerstedt

    Thermoelectric materials are capable of converting waste heat into usable electric energy. The conversion efficiency depends critically on the electronic band structure. Theoretical calculations predict the semiconducting ZnSb to have a promising efficiency if it is n-doped. The details of the lo......Thermoelectric materials are capable of converting waste heat into usable electric energy. The conversion efficiency depends critically on the electronic band structure. Theoretical calculations predict the semiconducting ZnSb to have a promising efficiency if it is n-doped. The details...... of the lowest conduction band have therefore been investigated. Electrons placed in the lowest conduction band are predicted to increase the bonding between second nearest neighbour atoms. This causes a lowering of the energy at special points in the first Brillouin zone. Thereby, the dispersion of the lowest...

  2. Financial Assets [share, bonds] & Ancylia

    Science.gov (United States)

    Maksoed, Wh-

    2016-11-01

    Instead Elaine Scarry: "Thermonuclear monarchy" reinvent Carry Nation since Aug 17, 1965 the Republic of Indonesia's President speech: "Reach to the Star", for "cancellation" usually found in External Debt herewith retrieved from "the Window of theWorld": Ancylia, feast in March, a month named after Mars, the god of war. "On March 19 they used to put on their biggest performance of gymnastics in order to "bribe" their god for another good year", further we have vacancy & "vacuum tube"- Bulat Air karena Pembuluh, Bulat Kata karena Mufakat" proverb from Minangkabau, West Sumatra. Follows March 19, 1984 are first prototype flight of IAI Astra Jet as well as March 19, 2012 invoice accompanies Electric car Kujang-193, Fainancial Assets [share, bonds] are the answer for "infrastructure" & state owned enterprises assets to be hedged first initial debt per capita accordances. Heartfelt gratitudes to HE. Mr. Ir. Sarwono Kusumaatmadja/PT. Smartfren INDONESIA.

  3. Characterization of C-S lyase from Lactobacillus delbrueckii subsp. bulgaricus ATCC BAA-365 and its potential role in food flavour applications.

    Science.gov (United States)

    Allegrini, Alessandra; Astegno, Alessandra; La Verde, Valentina; Dominici, Paola

    2017-04-01

    Volatile thiols have substantial impact on the aroma of many beverages and foods. Thus, the control of their formation, which has been linked to C-S lyase enzymatic activities, is of great significance in industrial applications involving food flavours. Herein, we have carried out a spectroscopic and functional characterization of a putative pyridoxal 5'-phosphate (PLP)-dependent C-S lyase from the lactic acid bacterium Lactobacillus delbrueckii subsp. bulgaricus ATCC BAA-365 (LDB C-S lyase). Recombinant LDB C-S lyase exists as a tetramer in solution and shows spectral properties of enzymes containing PLP as cofactor. The enzyme has a broad substrate specificity toward sulphur-containing amino acids with aminoethyl-L-cysteine and L-cystine being the most effective substrates over L-cysteine and L-cystathionine. Notably, the protein also reveals cysteine-S-conjugate β-lyase activity in vitro, and is able to cleave a cysteinylated substrate precursor into the corresponding flavour-contributing thiol, with a catalytic efficiency higher than L-cystathionine. Contrary to similar enzymes of other lactic acid bacteria however, LDB C-S lyase is not capable of α,γ-elimination activity towards L-methionine to produce methanethiol, which is a significant compound in flavour development. Based on our results, future developments can be expected regarding the flavour-forming potential of Lactobacillus C-S lyase and its use in enhancing food flavours. © The Authors 2017. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

  4. Comparative TEM study of bonded silicon/silicon interfaces fabricated by hydrophilic, hydrophobic and UHV wafer bonding

    International Nuclear Information System (INIS)

    Reznicek, A.; Scholz, R.; Senz, S.; Goesele, U.

    2003-01-01

    Wafers of Czochralski-grown silicon were bonded hydrophilically, hydrophobically and in ultrahigh vacuum (UHV) at room temperature. Wafers bonded hydrophilically adhere together by hydrogen bonds, those bonded hydrophobically by van der Waals forces and UHV-bonded ones by covalent bonds. Annealing the pre-bonded hydrophilic and hydrophobic wafer pairs in argon for 2 h at different temperatures increases the initially low bonding energy. UHV-bonded wafer pairs were also annealed to compare the results. Transmission electron microscopy (TEM) investigations show nano-voids at the interface. The void density depends on the initial bonding strength. During annealing the shape, coverage and density of the voids change significantly

  5. Are Bonding Agents being Effective on the Shear Bond Strength of Orthodontic Brackets Bonded to the Composite?

    Directory of Open Access Journals (Sweden)

    Fahimeh Farzanegan

    2014-06-01

    Full Text Available Introduction: One of the clinical problems in orthodontics is the bonding of brackets tocomposite restorations. The aim of this study was to evaluate the shear bondstrength of brackets bonded to composite restorations using Excite. Methods:Forty brackets were bonded to composite surfaces, which were embedded inacrylic resin. One of the following four protocols was employed for surfacepreparation of the composite: group 1 37% phosphoric acid for 60 seconds, group2 roughening with a diamond bur plus 37% phosphoric acid for 60 seconds, group3 37% phosphoric acid for 60 seconds and the applying Excite®, group4 roughening with diamond bur plus 37% phosphoric acid for 60 seconds andapplying Excite®. Maxillary central brackets were bonded onto thecomposite prepared samples with Transbond XT. Shear Bond Strength (SBS wasmeasured by a universal testing machine. The ANOVA and Tukey test was utilizedfor data analysis. Results: There was a significant difference betweenthe four groups (P

  6. Bonding Durability of Four Adhesive Systems

    Directory of Open Access Journals (Sweden)

    Leila Atash Biz Yeganeh

    2016-04-01

    Full Text Available Objectives: This study aimed to compare the durability of four adhesive systems by assessing their microtensile bond strength (MTBS and microleakage during six months of water storage.Materials and Methods: A total of 128 human third molars were used. The adhesives tested were Scotch Bond Multipurpose (SBMP, Single Bond (SB, Clearfil-SE bond (CSEB, and All-Bond SE (ABSE. After sample preparation for MTBS testing, the microspecimens were subjected to microtensile tester after one day and six months of water storage. For microleakage evaluation, facial and lingual class V cavities were prepared and restored with composite. After thermocycling, microleakage was evaluated. Bond strength values were subjected to one-way ANOVA and Tamhane’s test, and the microleakage data were analyzed by the Kruskal-Wallis, Dunn, Mann Whitney and Wilcoxon tests (P<0.05.Results: Single Bond yielded the highest and ABSE yielded the lowest bond strength at one day and six months. Short-term bond strength of SBMP and CSEB was similar. After six months, a significant decrease in bond strength was observed in ABSE and SBMP groups. At one day, ABSE showed the highest microleakage at the occlusal margin; however, at the gingival margin, there was no significant difference among groups. Long-term microleakage of all groups at the occlusal margins was similar, whilst gingival margins of SBMP and SB showed significantly higher microleakage.Conclusion: The highest MTBS and favorable sealability were obtained by Clearfil SE bond. Water storage had no effect on microleakage of self-etch adhesives at the gingival margin or MTBS of CSEB and SB. 

  7. Composite Laser Ceramics by Advanced Bonding Technology.

    Science.gov (United States)

    Ikesue, Akio; Aung, Yan Lin; Kamimura, Tomosumi; Honda, Sawao; Iwamoto, Yuji

    2018-02-09

    Composites obtained by bonding materials with the same crystal structure and different chemical compositions can create new functions that do not exist in conventional concepts. We have succeeded in bonding polycrystalline YAG and Nd:YAG ceramics without any interstices at the bonding interface, and the bonding state of this composite was at the atomic level, similar to the grain boundary structure in ceramics. The mechanical strength of the bonded composite reached 278 MPa, which was not less than the strength of each host material (269 and 255 MPa). Thermal conductivity of the composite was 12.3 W/mK (theoretical value) which is intermediate between the thermal conductivities of YAG and Nd:YAG (14.1 and 10.2 W/mK, respectively). Light scattering cannot be detected at the bonding interface of the ceramic composite by laser tomography. Since the scattering coefficients of the monolithic material and the composite material formed by bonding up to 15 layers of the same materials were both 0.10%/cm, there was no occurrence of light scattering due to the bonding. In addition, it was not detected that the optical distortion and non-uniformity of the refractive index variation were caused by the bonding. An excitation light source (LD = 808 nm) was collimated to 200 μm and irradiated into a commercial 1% Nd:YAG single crystal, but fracture damage occurred at a low damage threshold of 80 kW/cm². On the other hand, the same test was conducted on the bonded interface of 1% Nd:YAG-YAG composite ceramics fabricated in this study, but it was not damaged until the excitation density reached 127 kW/cm². 0.6% Nd:YAG-YAG composite ceramics showed high damage resistance (up to 223 kW/cm²). It was concluded that composites formed by bonding polycrystalline ceramics are ideal in terms of thermo-mechanical and optical properties.

  8. 77 FR 29472 - Surety Companies Acceptable on Federal Bonds-Termination: Atlantic Bonding Company, Inc.

    Science.gov (United States)

    2012-05-17

    ... be accepted from this company, and bonds that are continuous in nature should not be renewed. The... DEPARTMENT OF THE TREASURY Fiscal Service Surety Companies Acceptable on Federal Bonds--Termination: Atlantic Bonding Company, Inc. AGENCY: Financial Management Service, Fiscal Service, Department...

  9. Comparison of Shear Bond Strengths of three resin systems for a Base Metal Alloy bonded to

    Directory of Open Access Journals (Sweden)

    Jlali H

    1999-12-01

    Full Text Available Resin-bonded fixed partial dentures (F.P.D can be used for conservative treatment of partially edentulous"npatients. There are numerous studies regarding the strength of resin composite bond to base meta! alloys. Shear bond"nstrength of three resin systems were invistigated. In this study these systems consisted of: Panavia Ex, Mirage FLC and"nMarathon V. Thirty base metal specimens were prepared from rexillium III alloy and divided into three groups. Then each"ngroup was bonded to enamel of human extracted molar teeth with these systems. All of specimens were stored in water at"n37ac for 48 hours. A shear force was applied to each specimen by the instron universal testing machine. A statistical"nevaluation of the data using one-way analysis of variance showed that there was highly significant difference (P<0.01"nbetween the bond strengths of these three groups."nThe base metal specimens bonded with panavia Ex luting agent, exhibited the highest mean bond strength. Shear bond"nstrength of the specimens bonded to enamel with Mirage F1C showed lower bond strenght than panavia EX. However, the"nlowest bond strength was obtained by the specimens bonded with Marathon V.

  10. Hydrogen Bonds and Life in the Universe

    Directory of Open Access Journals (Sweden)

    Giovanni Vladilo

    2018-01-01

    Full Text Available The scientific community is allocating more and more resources to space missions and astronomical observations dedicated to the search for life beyond Earth. This experimental endeavor needs to be backed by a theoretical framework aimed at defining universal criteria for the existence of life. With this aim in mind, we have explored which chemical and physical properties should be expected for life possibly different from the terrestrial one, but similarly sustained by genetic and catalytic molecules. We show that functional molecules performing genetic and catalytic tasks must feature a hierarchy of chemical interactions operating in distinct energy bands. Of all known chemical bonds and forces, only hydrogen bonds are able to mediate the directional interactions of lower energy that are needed for the operation of genetic and catalytic tasks. For this reason and because of the unique quantum properties of hydrogen bonding, the functional molecules involved in life processes are predicted to have extensive hydrogen-bonding capabilities. A molecular medium generating a hydrogen-bond network is probably essential to support the activity of the functional molecules. These hydrogen-bond requirements constrain the viability of hypothetical biochemistries alternative to the terrestrial one, provide thermal limits to life molecular processes, and offer a conceptual framework to define a transition from a “covalent-bond stage” to a “hydrogen-bond stage” in prebiotic chemistry.

  11. 40 CFR 280.98 - Surety bond.

    Science.gov (United States)

    2010-07-01

    ...: Performance Bond Date bond executed: Period of coverage: Principal: [legal name and business address of owner... “corporation”] State of incorporation (if applicable): Surety(ies): [name(s) and business address(es)] Scope of...) shall not be discharged by any payment or succession of payments hereunder, unless and until such...

  12. Hydrogen bond dynamics in bulk alcohols

    International Nuclear Information System (INIS)

    Shinokita, Keisuke; Cunha, Ana V.; Jansen, Thomas L. C.; Pshenichnikov, Maxim S.

    2015-01-01

    Hydrogen-bonded liquids play a significant role in numerous chemical and biological phenomena. In the past decade, impressive developments in multidimensional vibrational spectroscopy and combined molecular dynamics–quantum mechanical simulation have established many intriguing features of hydrogen bond dynamics in one of the fundamental solvents in nature, water. The next class of a hydrogen-bonded liquid—alcohols—has attracted much less attention. This is surprising given such important differences between water and alcohols as the imbalance between the number of hydrogen bonds, each molecule can accept (two) and donate (one) and the very presence of the hydrophobic group in alcohols. Here, we use polarization-resolved pump-probe and 2D infrared spectroscopy supported by extensive theoretical modeling to investigate hydrogen bond dynamics in methanol, ethanol, and isopropanol employing the OH stretching mode as a reporter. The sub-ps dynamics in alcohols are similar to those in water as they are determined by similar librational and hydrogen-bond stretch motions. However, lower density of hydrogen bond acceptors and donors in alcohols leads to the appearance of slow diffusion-controlled hydrogen bond exchange dynamics, which are essentially absent in water. We anticipate that the findings herein would have a potential impact on fundamental chemistry and biology as many processes in nature involve the interplay of hydrophobic and hydrophilic groups

  13. 78 FR 36029 - CDFI Bond Guarantee Program

    Science.gov (United States)

    2013-06-14

    ... the extent a Secondary Loan is financed on a corporate finance basis (i.e., through a Credit... Issue. Bonds will be used to finance Bond Loans to Eligible CDFIs for Eligible Purposes for a period not... financial strength, stability, durability and liquidity as reflected in its corporate credit ratings and...

  14. Index Driven Price Pressure in Corporate Bonds

    DEFF Research Database (Denmark)

    Dick-Nielsen, Jens

    Inclusion and exclusion of bonds from major indices are information-free, monthly events. At these events, liquidity providers get a significant abnormal return by trading against index trackers. The return is highest for bonds that are excluded because of a recent downgrade with a one-day return...

  15. Sol-gel bonding of silicon wafers

    International Nuclear Information System (INIS)

    Barbe, C.J.; Cassidy, D.J.; Triani, G.; Latella, B.A.; Mitchell, D.R.G.; Finnie, K.S.; Bartlett, J.R.; Woolfrey, J.L.; Collins, G.A.

    2005-01-01

    Low temperature bonding of silicon wafers was achieved using sol-gel technology. The initial sol-gel chemistry of the coating solution was found to influence the mechanical properties of the resulting bonds. More precisely, the influence of parameters such as the alkoxide concentration, water-to-alkoxide molar ratio, pH, and solution aging on the final bond morphologies and interfacial fracture energy was studied. The thickness and density of the sol-gel coating were characterised using ellipsometry. The corresponding bonded specimens were investigated using attenuated total reflectance Fourier transformed infrared spectroscopy to monitor their chemical composition, infrared imaging to control bond integrity, and cross-sectional transmission electron microscopy to study their microstructure. Their interfacial fracture energy was measured using microindentation. An optimum water-to-alkoxide molar ratio of 10 and hydrolysis water at pH = 2 were found. Such conditions led to relatively dense films (> 90%), resulting in bonds with a fracture energy of 3.5 J/m 2 , significantly higher than those obtained using classical hydrophilic bonding (typically 1.5-2.5 J/m 2 ). Ageing of the coating solution was found to decrease the bond strength

  16. Theoretical Characterization of Hydrogen Bonding Interactions ...

    Indian Academy of Sciences (India)

    The highest stabilization results in case of (H2N)CHO as hydrogen bond acceptor. The variation of the substituents at –OH functional group also influences the strength of hydrogen bond; nearly all the substituents increase the stabilization energy relative to HOH. The analysis of geometrical parameters; proton affinities, ...

  17. Expected Business Conditions and Bond Risk Premia

    DEFF Research Database (Denmark)

    Eriksen, Jonas Nygaard

    2017-01-01

    In this article, I study the predictability of bond risk premia by means of expectations to future business conditions using survey forecasts from the Survey of Professional Forecasters. I show that expected business conditions consistently affect excess bond returns and that the inclusion of exp...

  18. Nondestructive testing of thermocompression bonds. Final report

    International Nuclear Information System (INIS)

    Hale, G.M.

    1981-02-01

    A Scanning Laser Acoustic Microscope (SLAM) was used to characterize hybrid microcircuit beam lead bonds formed on thin film networks by a thermocompression process. Results from subsequent pull testing show that the SLAM offered no significant advantage over visual inspection for detecting bad bonds. Infrared microscopy and resistance measurements were also reviewed and rejected as being ineffective inspection methods

  19. 46 CFR 540.6 - Surety bonds.

    Science.gov (United States)

    2010-10-01

    ... transportation. The requirements of Form FMC-132A, however, may be amended by the Commission in a particular case for good cause. (b) In the case of a surety bond which is to cover all passenger operations of the... shall be issued by a bonding company authorized to do business in the United States and acceptable to...

  20. Hydrogen Bonds and Life in the Universe

    Science.gov (United States)

    2018-01-01

    The scientific community is allocating more and more resources to space missions and astronomical observations dedicated to the search for life beyond Earth. This experimental endeavor needs to be backed by a theoretical framework aimed at defining universal criteria for the existence of life. With this aim in mind, we have explored which chemical and physical properties should be expected for life possibly different from the terrestrial one, but similarly sustained by genetic and catalytic molecules. We show that functional molecules performing genetic and catalytic tasks must feature a hierarchy of chemical interactions operating in distinct energy bands. Of all known chemical bonds and forces, only hydrogen bonds are able to mediate the directional interactions of lower energy that are needed for the operation of genetic and catalytic tasks. For this reason and because of the unique quantum properties of hydrogen bonding, the functional molecules involved in life processes are predicted to have extensive hydrogen-bonding capabilities. A molecular medium generating a hydrogen-bond network is probably essential to support the activity of the functional molecules. These hydrogen-bond requirements constrain the viability of hypothetical biochemistries alternative to the terrestrial one, provide thermal limits to life molecular processes, and offer a conceptual framework to define a transition from a “covalent-bond stage” to a “hydrogen-bond stage” in prebiotic chemistry. PMID:29301382

  1. Hydrogen bond dynamics in bulk alcohols.

    Science.gov (United States)

    Shinokita, Keisuke; Cunha, Ana V; Jansen, Thomas L C; Pshenichnikov, Maxim S

    2015-06-07

    Hydrogen-bonded liquids play a significant role in numerous chemical and biological phenomena. In the past decade, impressive developments in multidimensional vibrational spectroscopy and combined molecular dynamics-quantum mechanical simulation have established many intriguing features of hydrogen bond dynamics in one of the fundamental solvents in nature, water. The next class of a hydrogen-bonded liquid--alcohols--has attracted much less attention. This is surprising given such important differences between water and alcohols as the imbalance between the number of hydrogen bonds, each molecule can accept (two) and donate (one) and the very presence of the hydrophobic group in alcohols. Here, we use polarization-resolved pump-probe and 2D infrared spectroscopy supported by extensive theoretical modeling to investigate hydrogen bond dynamics in methanol, ethanol, and isopropanol employing the OH stretching mode as a reporter. The sub-ps dynamics in alcohols are similar to those in water as they are determined by similar librational and hydrogen-bond stretch motions. However, lower density of hydrogen bond acceptors and donors in alcohols leads to the appearance of slow diffusion-controlled hydrogen bond exchange dynamics, which are essentially absent in water. We anticipate that the findings herein would have a potential impact on fundamental chemistry and biology as many processes in nature involve the interplay of hydrophobic and hydrophilic groups.

  2. Sol-gel bonding of silicon wafers

    International Nuclear Information System (INIS)

    Barbe, C.J.; Cassidy, D.J.; Triani, G.; Latella, B.A.; Mitchell, D.R.G.; Finnie, K.S.; Short, K.; Bartlett, J.R.; Woolfrey, J.L.; Collins, G.A.

    2005-01-01

    Sol-gel bonds have been produced between smooth, clean silicon substrates by spin-coating solutions containing partially hydrolysed silicon alkoxides. The two coated substrates were assembled and the resulting sandwich fired at temperatures ranging from 60 to 600 deg. C. The sol-gel coatings were characterised using attenuated total reflectance Fourier transform infrared spectroscopy, ellipsometry, and atomic force microscopy, while the corresponding bonded specimens were investigated using scanning electron microscopy and cross-sectional transmission electron microscopy. Mechanical properties were characterised using both microindentation and tensile testing. Bonding of silicon wafers has been successfully achieved at temperatures as low as 60 deg. C. At 300 deg. C, the interfacial fracture energy was 1.55 J/m 2 . At 600 deg. C, sol-gel bonding provided superior interfacial fracture energy over classical hydrophilic bonding (3.4 J/m 2 vs. 1.5 J/m 2 ). The increase in the interfacial fracture energy is related to the increase in film density due to the sintering of the sol-gel interface with increasing temperature. The superior interfacial fracture energy obtained by sol-gel bonding at low temperature is due to the formation of an interfacial layer, which chemically bonds the two sol-gel coatings on each wafer. Application of a tensile stress on the resulting bond leads to fracture of the samples at the silicon/sol-gel interface

  3. 76 FR 38577 - Bond Guarantee Program

    Science.gov (United States)

    2011-07-01

    ... notes or bonds, including the principal, interest, and call premiums not to exceed 30 years, issued by CDFIs to finance loans for eligible community or economic development purposes. The bonds or notes will... accordance with Federal credit policy, moreover, the Federal Financing Bank (FFB), a body corporate and...

  4. Hydrogen Bonds and Life in the Universe.

    Science.gov (United States)

    Vladilo, Giovanni; Hassanali, Ali

    2018-01-03

    The scientific community is allocating more and more resources to space missions and astronomical observations dedicated to the search for life beyond Earth. This experimental endeavor needs to be backed by a theoretical framework aimed at defining universal criteria for the existence of life. With this aim in mind, we have explored which chemical and physical properties should be expected for life possibly different from the terrestrial one, but similarly sustained by genetic and catalytic molecules. We show that functional molecules performing genetic and catalytic tasks must feature a hierarchy of chemical interactions operating in distinct energy bands. Of all known chemical bonds and forces, only hydrogen bonds are able to mediate the directional interactions of lower energy that are needed for the operation of genetic and catalytic tasks. For this reason and because of the unique quantum properties of hydrogen bonding, the functional molecules involved in life processes are predicted to have extensive hydrogen-bonding capabilities. A molecular medium generating a hydrogen-bond network is probably essential to support the activity of the functional molecules. These hydrogen-bond requirements constrain the viability of hypothetical biochemistries alternative to the terrestrial one, provide thermal limits to life molecular processes, and offer a conceptual framework to define a transition from a "covalent-bond stage" to a "hydrogen-bond stage" in prebiotic chemistry.

  5. Fusion bonding of silicon nitride surfaces

    DEFF Research Database (Denmark)

    Reck, Kasper; Østergaard, Christian; Thomsen, Erik Vilain

    2011-01-01

    While silicon nitride surfaces are widely used in many micro electrical mechanical system devices, e.g. for chemical passivation, electrical isolation or environmental protection, studies on fusion bonding of two silicon nitride surfaces (Si3N4–Si3N4 bonding) are very few and highly application...

  6. ROLE OF DIASPORA BONDS IN DEVELOPING COUNTRIES

    Directory of Open Access Journals (Sweden)

    Y. Bunyk

    2015-08-01

    Full Text Available The article deals with the problem of the bond issue for the Diaspora as a source of financing of the national economy and a factor of development. We reveal the following factors driving demand in the diaspora bond market: targeting at a project, channels, audience and marketing. The paper shows international experience to attract migrants’ savings and use them to issue bonds. Investors consider diaspora bonds because: firstly, people who have disposable income, who can commit that income or that excess income to a long term investment should look at diaspora bonds: secondly, people who really want to participate in transforming the home country should look at diaspora bond specifically diaspora bonds related to projects: and last but not least, if there are incentives around diaspora bonds for example whether there’s tax incentive and other kinds of incentive, that also should be taken into account. Also we disclosed the possibility of using this type of securities in Ukraine and its expedience.

  7. Green and social bonds - A promising tool

    International Nuclear Information System (INIS)

    Blanc, Dominique; Barochez, Aurelie de; Cozic, Aela

    2013-11-01

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

  8. Structural and nano-mechanical properties of Calcium Silicate Hydrate (C-S-H) formed from alite hydration in the presence of sodium and potassium hydroxide

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza, Oscar, E-mail: oamendoz@unal.edu.co [Grupo del Cemento y Materiales de Construcción (CEMATCO). Universidad Nacional de Colombia, Facultad de Minas, Medellín (Colombia); Giraldo, Carolina [Cementos Argos S.A., Medellín (Colombia); Camargo, Sergio S. [Engenharia Metalúrgica e de Materiais, Universidade Federal do Rio de Janeiro/COPPE, Rio de Janeiro (Brazil); Tobón, Jorge I. [Grupo del Cemento y Materiales de Construcción (CEMATCO). Universidad Nacional de Colombia, Facultad de Minas, Medellín (Colombia)

    2015-08-15

    This research evaluates the effect of sodium and potassium hydroxide on the structure and nano-mechanical properties of Calcium Silicate Hydrate (C-S-H) formed from the hydration of pure alite. Monoclinic (MIII) alite was synthesized and hydrated, using water-to-alite ratios of 0.5 and 0.6 and additions of 10% NaOH and KOH by weight of alite. Based on results of X-ray diffraction, isothermal calorimetry, thermogravimetric analysis, Nuclear Magnetic Resonance and nanoindentation, two different effects of the alkaline hydroxides on the hydration reaction of alite, both at early and later ages, can be identified: (i) a differentiated hydration process, attributed to an enhancement in calcium hydroxide (CH) precipitation and a stimulation of the C-S-H nuclei; and (ii) an increase in the elastic modulus of the C-S-H aggregations, attributed to an electrostatic attraction between positive charges from the alkaline cations and negative charges from the C-S-H structure.

  9. Management of a Septic Open Abdomen Patient with Spontaneous Jejunal Perforation after Emergent C/S with Confounding Factor of Mild Acute Pancreatitis.

    Science.gov (United States)

    Yetisir, Fahri; Sarer, Akgün Ebru; Acar, Hasan Zafer; Osmanoglu, Gokhan; Özer, Mehmet; Yaylak, Faik

    2016-01-01

    Introduction. We report the management of a septic Open Abdomen (OA) patient by the help of negative pressure therapy (NPT) and abdominal reapproximation anchor (ABRA) system in pregnant woman with spontaneous jejunal perforation after emergent cesarean section (C/S) with confounding factor of mild acute pancreatitis (AP). Presentation of Case. A 29-year-old and 34-week pregnant woman with AP underwent C/S. She was arrested after anesthesia induction and responded to cardiopulmonary resuscitation (CPR). There were only ash-colored serosanguinous fluid within abdomen during C/S. After C/S, she was transferred to intensive care unit (ICU) with vasopressor support. On postoperative 1st day, she underwent reoperation due to fecal fluid coming near the drainage. Leakage point could not be identified exactly and operation had to be deliberately abbreviated due to hemodynamic instability. NPT was applied. Two days later source control was provided by conversion of enteroatmospheric fistula (EAF) to jejunostomy. ABRA was added and OA was closed. No hernia developed at 10-month follow-up period. Conclusion. NPT application in septic OA patient may gain time to patient until adequate source control could be achieved. Using ABRA in conjunction with NPT increases the fascial closure rate in infected OA patient.

  10. Structural and nano-mechanical properties of Calcium Silicate Hydrate (C-S-H) formed from alite hydration in the presence of sodium and potassium hydroxide

    International Nuclear Information System (INIS)

    Mendoza, Oscar; Giraldo, Carolina; Camargo, Sergio S.; Tobón, Jorge I.

    2015-01-01

    This research evaluates the effect of sodium and potassium hydroxide on the structure and nano-mechanical properties of Calcium Silicate Hydrate (C-S-H) formed from the hydration of pure alite. Monoclinic (MIII) alite was synthesized and hydrated, using water-to-alite ratios of 0.5 and 0.6 and additions of 10% NaOH and KOH by weight of alite. Based on results of X-ray diffraction, isothermal calorimetry, thermogravimetric analysis, Nuclear Magnetic Resonance and nanoindentation, two different effects of the alkaline hydroxides on the hydration reaction of alite, both at early and later ages, can be identified: (i) a differentiated hydration process, attributed to an enhancement in calcium hydroxide (CH) precipitation and a stimulation of the C-S-H nuclei; and (ii) an increase in the elastic modulus of the C-S-H aggregations, attributed to an electrostatic attraction between positive charges from the alkaline cations and negative charges from the C-S-H structure

  11. Management of a Septic Open Abdomen Patient with Spontaneous Jejunal Perforation after Emergent C/S with Confounding Factor of Mild Acute Pancreatitis

    Directory of Open Access Journals (Sweden)

    Fahri Yetisir

    2016-01-01

    Full Text Available Introduction. We report the management of a septic Open Abdomen (OA patient by the help of negative pressure therapy (NPT and abdominal reapproximation anchor (ABRA system in pregnant woman with spontaneous jejunal perforation after emergent cesarean section (C/S with confounding factor of mild acute pancreatitis (AP. Presentation of Case. A 29-year-old and 34-week pregnant woman with AP underwent C/S. She was arrested after anesthesia induction and responded to cardiopulmonary resuscitation (CPR. There were only ash-colored serosanguinous fluid within abdomen during C/S. After C/S, she was transferred to intensive care unit (ICU with vasopressor support. On postoperative 1st day, she underwent reoperation due to fecal fluid coming near the drainage. Leakage point could not be identified exactly and operation had to be deliberately abbreviated due to hemodynamic instability. NPT was applied. Two days later source control was provided by conversion of enteroatmospheric fistula (EAF to jejunostomy. ABRA was added and OA was closed. No hernia developed at 10-month follow-up period. Conclusion. NPT application in septic OA patient may gain time to patient until adequate source control could be achieved. Using ABRA in conjunction with NPT increases the fascial closure rate in infected OA patient.

  12. Mechanics of wafer bonding: Effect of clamping

    Science.gov (United States)

    Turner, K. T.; Thouless, M. D.; Spearing, S. M.

    2004-01-01

    A mechanics-based model is developed to examine the effects of clamping during wafer bonding processes. The model provides closed-form expressions that relate the initial geometry and elastic properties of the wafers to the final shape of the bonded pair and the strain energy release rate at the interface for two different clamping configurations. The results demonstrate that the curvature of bonded pairs may be controlled through the use of specific clamping arrangements during the bonding process. Furthermore, it is demonstrated that the strain energy release rate depends on the clamping configuration and that using applied loads usually leads to an undesirable increase in the strain energy release rate. The results are discussed in detail and implications for process development and bonding tool design are highlighted.

  13. Diffusion bonding in compact heat exchangers

    International Nuclear Information System (INIS)

    Southall, David

    2009-01-01

    Heatric's diffusion bonding process is a solid-state joining technology that produces strong, compact, all-metal heat exchanger cores. Diffusion bonding allows for a large quantity of joints to be made in geometries that would normally be inaccessible for conventional welding techniques. Since Heatric's diffusion bonding process uses no interlayer or braze alloy, the resulting heat exchanger core has consistent chemistry throughout and, under carefully controlled conditions, a return to parent metal strength can be reached. This paper will provide an overview of the diffusion bonding process and its origins, and also its application to compact heat exchanger construction. The paper will then discuss recent work that has been done to compare mechanical properties of Heatric's diffusion bonded material with material that has been conventionally welded, as well as with material tested in the as-received condition. (author)

  14. 1 mil gold bond wire study.

    Energy Technology Data Exchange (ETDEWEB)

    Huff, Johnathon; McLean, Michael B.; Jenkins, Mark W.; Rutherford, Brian Milne

    2013-05-01

    In microcircuit fabrication, the diameter and length of a bond wire have been shown to both affect the current versus fusing time ratio of a bond wire as well as the gap length of the fused wire. This study investigated the impact of current level on the time-to-open and gap length of 1 mil by 60 mil gold bond wires. During the experiments, constant current was provided for a control set of bond wires for 250ms, 410ms and until the wire fused; non-destructively pull-tested wires for 250ms; and notched wires. The key findings were that as the current increases, the gap length increases and 73% of the bond wires will fuse at 1.8A, and 100% of the wires fuse at 1.9A within 60ms. Due to the limited scope of experiments and limited data analyzed, further investigation is encouraged to confirm these observations.

  15. Bonded exciplex formation: electronic and stereoelectronic effects.

    Science.gov (United States)

    Wang, Yingsheng; Haze, Olesya; Dinnocenzo, Joseph P; Farid, Samir; Farid, Ramy S; Gould, Ian R

    2008-12-18

    As recently proposed, the singlet-excited states of several cyanoaromatics react with pyridine via bonded-exciplex formation, a novel concept in photochemical charge transfer reactions. Presented here are electronic and steric effects on the quenching rate constants, which provide valuable support for the model. Additionally, excited-state quenching in poly(vinylpyridine) is strongly inhibited both relative to that in neat pyridine and also to conventional exciplex formation in polymers, consistent with a restrictive orientational requirement for the formation of bonded exciplexes. Examples of competing reactions to form both conventional and bonded exciplexes are presented, which illustrate the delicate balance between these two processes when their reaction energetics are similar. Experimental and computational evidence is provided for the formation of a bonded exciplex in the reaction of the singlet excited state of 2,6,9,10-tetracyanoanthracene (TCA) with an oxygen-substituted donor, dioxane, thus expanding the scope of bonded exciplexes.

  16. PMMA to Polystyrene bonding for polymer based microfluidic systems

    KAUST Repository

    Fan, Yiqiang

    2013-03-29

    A thermal bonding technique for Poly (methylmethacrylate) (PMMA) to Polystyrene (PS) is presented in this paper. The PMMA to PS bonding was achieved using a thermocompression method, and the bonding strength was carefully characterized. The bonding temperature ranged from 110 to 125 C with a varying compression force, from 700 to 1,000 N (0.36-0.51 MPa). After the bonding process, two kinds of adhesion quantification methods were used to measure the bonding strength: the double cantilever beam method and the tensile stress method. The results show that the bonding strength increases with a rising bonding temperature and bonding force. The results also indicate that the bonding strength is independent of bonding time. A deep-UV surface treatment method was also provided in this paper to lower the bonding temperature and compression force. Finally, a PMMA to PS bonded microfluidic device was fabricated successfully. © 2013 Springer-Verlag Berlin Heidelberg.

  17. Predicting Bond Betas using Macro-Finance Variables

    DEFF Research Database (Denmark)

    Aslanidis, Nektarios; Christiansen, Charlotte; Cipollini, Andrea

    We conduct in-sample and out-of-sample forecasting using the new approach of combining explanatory variables through complete subset regressions (CSR). We predict bond CAPM betas and bond returns conditioning on various macro-fi…nance variables. We explore differences across long-term government ...... bonds, investment grade corporate bonds, and high-yield corporate bonds. The CSR method performs well in predicting bond betas, especially in-sample, and, mainly high-yield bond betas when the focus is out-of-sample. Bond returns are less predictable than bond betas....

  18. Evidence for Interfacial Halogen Bonding.

    Science.gov (United States)

    Swords, Wesley B; Simon, Sarah J C; Parlane, Fraser G L; Dean, Rebecca K; Kellett, Cameron W; Hu, Ke; Meyer, Gerald J; Berlinguette, Curtis P

    2016-05-10

    A homologous series of donor-π-acceptor dyes was synthesized, differing only in the identity of the halogen substituents about the triphenylamine (TPA; donor) portion of each molecule. Each Dye-X (X=F, Cl, Br, and I) was immobilized on a TiO2 surface to investigate how the halogen substituents affect the reaction between the light-induced charge-separated state, TiO2 (e(-) )/Dye-X(+) , with iodide in solution. Transient absorption spectroscopy showed progressively faster reactivity towards nucleophilic iodide with more polarizable halogen substituents: Dye-F < Dye-Cl < Dye-Br < Dye-I. Given that all other structural and electronic properties for the series are held at parity, with the exception of an increasingly larger electropositive σ-hole on the heavier halogens, the differences in dye regeneration kinetics for Dye-Cl, Dye-Br, and Dye-I are ascribed to the extent of halogen bonding with the nucleophilic solution species. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. 48 CFR 728.105-1 - Advance payment bonds.

    Science.gov (United States)

    2010-10-01

    ... GENERAL CONTRACTING REQUIREMENTS BONDS AND INSURANCE Bonds 728.105-1 Advance payment bonds. (a) Generally, advance payment bonds will not be required in connection with USAID contracts containing an advance... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Advance payment bonds. 728...

  20. 7 CFR 1780.95 - Public bidding on bonds.

    Science.gov (United States)

    2010-01-01

    ... public bidding. The Agency will not submit a bid at the advertised sale unless required by State law, nor... 7 Agriculture 12 2010-01-01 2010-01-01 false Public bidding on bonds. 1780.95 Section 1780.95... Bonds and Bond Transcript Documents for Public Body Applicants § 1780.95 Public bidding on bonds. Bonds...

  1. Bond-Slip Relationship for CFRP Sheets Externally Bonded to Concrete under Cyclic Loading.

    Science.gov (United States)

    Li, Ke; Cao, Shuangyin; Yang, Yue; Zhu, Juntao

    2018-02-26

    The objective of this paper was to explore the bond-slip relationship between carbon fiber-reinforced polymer (CFRP) sheets and concrete under cyclic loading through experimental and analytical approaches. Modified beam tests were performed in order to gain insight into the bond-slip relationship under static and cyclic loading. The test variables are the CFRP-to-concrete width ratio, and the bond length of the CFRP sheets. An analysis of the test results in this paper and existing test results indicated that the slope of the ascending segment of the bond-slip curve decreased with an increase in the number of load cycles, but the slip corresponding to the maximum shear stress was almost invariable as the number of load cycles increased. In addition, the rate of reduction in the slope of the ascending range of the bond-slip curve during cyclic loading decreased as the concrete strength increased, and increased as the load level or CFRP-to-concrete width ratio enhanced. However, these were not affected by variations in bond length if the residual bond length was longer than the effective bond length. A bilinear bond-slip model for CFRP sheets that are externally bonded to concrete under cyclic loading, which considered the effects of the cyclic load level, concrete strength, and CFRP-to-concrete ratio, was developed based on the existing static bond-slip model. The accuracy of this proposed model was verified by a comparison between this proposed model and test results.

  2. Effect of nanoscale surface roughness on the bonding energy of direct-bonded silicon wafers

    Science.gov (United States)

    Miki, N.; Spearing, S. M.

    2003-11-01

    Direct wafer bonding of silicon wafers is a promising technology for manufacturing three-dimensional complex microelectromechanical systems as well as silicon-on-insulator substrates. Previous work has reported that the bond quality declines with increasing surface roughness, however, this relationship has not been quantified. This article explicitly correlates the bond quality, which is quantified by the apparent bonding energy, and the surface morphology via the bearing ratio, which describes the area of surface lying above a given depth. The apparent bonding energy is considered to be proportional to the real area of contact. The effective area of contact is defined as the area sufficiently close to contribute to the attractive force between the two bonding wafers. Experiments were conducted with silicon wafers whose surfaces were roughened by a buffered oxide etch solution (BOE, HF:NH4F=1:7) and/or a potassium hydroxide solution. The surface roughness was measured by atomic force microscopy. The wafers were direct bonded to polished "monitor" wafers following a standard RCA cleaning and the resulting bonding energy was measured by the crack-opening method. The experimental results revealed a clear correlation between the bonding energy and the bearing ratio. A bearing depth of ˜1.4 nm was found to be appropriate for the characterization of direct-bonded silicon at room temperature, which is consistent with the thickness of the water layer at the interface responsible for the hydrogen bonds that link the mating wafers.

  3. Destination bonding: Hybrid cognition using Instagram

    Directory of Open Access Journals (Sweden)

    Arup Kumar Baksi

    2015-01-01

    Full Text Available Empirical research has identified the phenomenon of destination bonding as a result of summated physical and emotional values associated with the destination. Physical values, namely natural landscape & other physical settings and emotional values, namely the enculturation processes, have a significant role to play in portraying visitors’ cognitive framework for destination preference. The physical values seemed to be the stimulator for bonding that embodies action or behavior tendencies in imagery. The emotional values were the conditions that lead to affective bonding and are reflected in attitudes for a place which were evident in text narratives. Social networking on virtual platforms offers the scope for hybrid cognitive expression using imagery and text to the visitors. Instagram has emerged as an application-window to capture these hybrid cognitions of visitors. This study focuses on assessing the relationship between hybrid cognition of visitors expressed via Instagram and their bond with the destination. Further to this, the study attempts to examine the impact of hybrid cognition of visitors on the behavioral pattern of prospective visitors to the destination. The study revealed that sharing of visual imageries and related text by the visitors is an expression of the physico-emotional bonding with the destination. It was further established that hybrid cognition strongly asserts destination bonding and has been also found to have moderating impact on the link between destination bonding and electronic-word-of-mouth.

  4. Bond financing for renewable energy in Asia

    International Nuclear Information System (INIS)

    Ng, Thiam Hee; Tao, Jacqueline Yujia

    2016-01-01

    Addressing the financing gap for renewable energy (RE) projects in Asia is critical to ensure that the rapidly increasing energy needs could be met sustainably. This paper explores the cause of the financing gap in Asia and proposes the use of bond financing to address the financing gap. Specifically, three fixed income instruments, namely local currency denominated (LCY) corporate bonds, asset backed project bonds and financial green bonds, will be assessed. Whilst the potential for these three instruments to mobilize large flows of private sector financing is great, key supportive policies aimed at reducing the capital market bias for conventional power generation technologies and supportive RE policies are required. Another key aspect would be the necessary deepening of local and regional fixed income markets before such capital market instruments are able to play a big role. - Highlights: •This study looks at the current financing gap and RE financing landscape in developing Asia. •LCY corporate bonds, asset backed projects bonds and financial green bonds could help to address the financing gap for RE in the region. •Policy recommendations for building the fixed income market for RE projects are provided.

  5. Bone bonding at natural and biomaterial surfaces.

    Science.gov (United States)

    Davies, John E

    2007-12-01

    Bone bonding is occurring in each of us and all other terrestrial vertebrates throughout life at bony remodeling sites. The surface created by the bone-resorbing osteoclast provides a three-dimensionally complex surface with which the cement line, the first matrix elaborated during de novo bone formation, interdigitates and is interlocked. The structure and composition of this interfacial bony matrix has been conserved during evolution across species; and we have known for over a decade that this interfacial matrix can be recapitulated at a biomaterial surface implanted in bone, given appropriate healing conditions. No evidence has emerged to suggest that bone bonding to artificial materials is any different from this natural biological process. Given this understanding it is now possible to explain why bone-bonding biomaterials are not restricted to the calcium-phosphate-based bioactive materials as was once thought. Indeed, in the absence of surface porosity, calcium phosphate biomaterials are not bone bonding. On the contrary, non-bonding materials can be rendered bone bonding by modifying their surface topography. This paper argues that the driving force for bone bonding is bone formation by contact osteogenesis, but that this has to occur on a sufficiently stable recipient surface which has micron-scale surface topography with undercuts in the sub-micron scale-range.

  6. Protection of MOS capacitors during anodic bonding

    Science.gov (United States)

    Schjølberg-Henriksen, K.; Plaza, J. A.; Rafí, J. M.; Esteve, J.; Campabadal, F.; Santander, J.; Jensen, G. U.; Hanneborg, A.

    2002-07-01

    We have investigated the electrical damage by anodic bonding on CMOS-quality gate oxide and methods to prevent this damage. n-type and p-type MOS capacitors were characterized by quasi-static and high-frequency CV-curves before and after anodic bonding. Capacitors that were bonded to a Pyrex wafer with 10 μm deep cavities enclosing the capacitors exhibited increased leakage current and interface trap density after bonding. Two different methods were successful in protecting the capacitors from such damage. Our first approach was to increase the cavity depth from 10 μm to 50 μm, thus reducing the electric field across the gate oxide during bonding from approximately 2 × 105 V cm-1 to 4 × 104 V cm-1. The second protection method was to coat the inside of a 10 μm deep Pyrex glass cavity with aluminium, forming a Faraday cage that removed the electric field across the cavity during anodic bonding. Both methods resulted in capacitors with decreased interface trap density and unchanged leakage current after bonding. No change in effective oxide charge or mobile ion contamination was observed on any of the capacitors in the study.

  7. Atomically Bonded Transparent Superhydrophobic Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Aytug, Tolga [ORNL

    2015-08-01

    Maintaining clarity and avoiding the accumulation of water and dirt on optically transparent surfaces such as US military vehicle windshields, viewports, periscope optical head windows, and electronic equipment cover glasses are critical to providing a high level of visibility, improved survivability, and much-needed safety for warfighters in the field. Through a combination of physical vapor deposition techniques and the exploitation of metastable phase separation in low-alkali borosilicate, a novel technology was developed for the fabrication of optically transparent, porous nanostructured silica thin film coatings that are strongly bonded to glass platforms. The nanotextured films, initially structurally superhydrophilic, exhibit superior superhydrophobicity, hence antisoiling ability, following a simple but robust modification in surface chemistry. The surfaces yield water droplet contact angles as high as 172°. Moreover, the nanostructured nature of these coatings provides increased light scattering in the UV regime and reduced reflectivity (i.e., enhanced transmission) over a broad range of the visible spectrum. In addition to these functionalities, the coatings exhibit superior mechanical resistance to abrasion and are thermally stable to temperatures approaching 500°C. The overall process technology relies on industry standard equipment and inherently scalable manufacturing processes and demands only nontoxic, naturally abundant, and inexpensive base materials. Such coatings, applied to the optical components of current and future combat equipment and military vehicles will provide a significant strategic advantage for warfighters. The inherent self-cleaning properties of such superhydrophobic coatings will also mitigate biofouling of optical windows exposed to high-humidity conditions and can help decrease repair/replacement costs, reduce maintenance, and increase readiness by limiting equipment downtime.

  8. Expected Business Conditions and Bond Risk Premia

    DEFF Research Database (Denmark)

    Eriksen, Jonas Nygaard

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

  9. Solitons on H bonds in proteins

    DEFF Research Database (Denmark)

    d'Ovidio, F.; Bohr, H.G.; Lindgård, Per-Anker

    2003-01-01

    system shows that the solitons are spontaneously created and are stable and moving along the helix axis. A perturbation on one of the three H-bond lines forms solitons on the other H bonds as well. The robust solitary wave may explain very long-lived modes in the frequency range of 100 cm(-1) which...... are found in recent x-ray laser experiments. The dynamics parameters of the Toda lattice are in accordance with the usual Lennard-Jones parameters used for realistic H-bond potentials in proteins....

  10. The Cost of Immediacy for Corporate Bonds

    DEFF Research Database (Denmark)

    Dick-Nielsen, Jens; Marco, Rossi

    Liquidity provision in the corporate bond market has become significantly more expensive after the 2008 credit crisis. Using index exclusions as a natural experiment during which uninformed index trackers request immediacy, we find that the price of immediacy has doubled for short-term investment...... grade bonds, and more than tripled for speculative-grade bonds. The increased cost of immediacy is a side-effect of a ban on proprietary trading (Volker Rule) and tighter post-crisis capital regulations, which have resulted in lower aggregate dealer inventories....

  11. Love Thy Neighbor: Bonding versus Bridging Trust

    OpenAIRE

    Poulsen, Odile; Svendsen, Gert Tinggaard

    2005-01-01

    We study how trust is generated in society. In a two-sector model, we analyze two communities. In the bonding community people do not trust people outside their regular networks. In the bridging community people choose to trust strangers when they meet them. The hypothesis is that when trust is only bonding, it cannot accumulate. Our theoretical contribution is to show that when trust is only bonding then the economy’s level of trust moves to an unstable equilibrium that may under certain con...

  12. Unusual bond paths in organolithium compounds

    International Nuclear Information System (INIS)

    Bachrach, S.M.; Ritchie, J.P.

    1986-01-01

    We have applied the topological method to a number of organolithium compounds. The wavefunctions were determined with GAUSSIAN-82 using 3-21G basis set and fully optimized geometries. Gradient paths were obtained using the RHODER package and critical points were located using EXTREME. These results indicate the unusual nature of organolithium compounds. The strange bond paths arise mainly from the ionic nature of the C-Li interaction. We suggest that the term ''bond path'' may best be suited for covalent bonds. 4 figs., 1 tab

  13. Quantum mechanical facets of chemical bonds

    International Nuclear Information System (INIS)

    Daudel, R.

    1976-01-01

    To define the concept of bond is both a central problem of quantum chemistry and a difficult one. The concept of bond appeared little by little in the mind of chemists from empirical observations. From the wave-mechanical viewpoint it is not an observable. Therefore there is no precise operator associated with that concept. As a consequence there is not a unique approach to the idea of chemical bond. This is why it is preferred to present various quantum mechanical facets, e.g. the energetic facet, the density facet, the partitioning facet and the functional facet, of that important concept. (Auth.)

  14. Cocrystals of 6-propyl-2-thiouracil: N-H···O versus N-H···S hydrogen bonds.

    Science.gov (United States)

    Tutughamiarso, Maya; Egert, Ernst

    2011-11-01

    In order to investigate the relative stability of N-H···O and N-H···S hydrogen bonds, we cocrystallized the antithyroid drug 6-propyl-2-thiouracil with two complementary heterocycles. In the cocrystal pyrimidin-2-amine-6-propyl-2-thiouracil (1/2), C(4)H(5)N(3)·2C(7)H(10)N(2)OS, (I), the `base pair' is connected by one N-H···S and one N-H···N hydrogen bond. Homodimers of 6-propyl-2-thiouracil linked by two N-H···S hydrogen bonds are observed in the cocrystal N-(6-acetamidopyridin-2-yl)acetamide-6-propyl-2-thiouracil (1/2), C(9)H(11)N(3)O(2)·2C(7)H(10)N(2)OS, (II). The crystal structure of 6-propyl-2-thiouracil itself, C(7)H(10)N(2)OS, (III), is stabilized by pairwise N-H···O and N-H···S hydrogen bonds. In all three structures, N-H···S hydrogen bonds occur only within R(2)(2)(8) patterns, whereas N-H···O hydrogen bonds tend to connect the homo- and heterodimers into extended networks. In agreement with related structures, the hydrogen-bonding capability of C=O and C=S groups seems to be comparable.

  15. Composite Bonding to Stainless Steel Crowns Using a New Universal Bonding and Single-Bottle Systems

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Hattan

    2013-01-01

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

  16. Room temperature Cu-Cu direct bonding using surface activated bonding method

    International Nuclear Information System (INIS)

    Kim, T.H.; Howlader, M.M.R.; Itoh, T.; Suga, T.

    2003-01-01

    Thin copper (Cu) films of 80 nm thickness deposited on a diffusion barrier layered 8 in. silicon wafers were directly bonded at room temperature using the surface activated bonding method. A low energy Ar ion beam of 40-100 eV was used to activate the Cu surface prior to bonding. Contacting two surface-activated wafers enables successful Cu-Cu direct bonding. The bonding process was carried out under an ultrahigh vacuum condition. No thermal annealing was required to increase the bonding strength since the bonded interface was strong enough at room temperature. The chemical constitution of the Cu surface was examined by Auger electron spectroscope. It was observed that carbon-based contaminations and native oxides on copper surface were effectively removed by Ar ion beam irradiation for 60 s without any wet cleaning processes. An atomic force microscope study shows that the Ar ion beam process causes no surface roughness degradation. Tensile test results show that high bonding strength equivalent to bulk material is achieved at room temperature. The cross-sectional transmission electron microscope observations reveal the presence of void-free bonding interface without intermediate layer at the bonded Cu surfaces

  17. A simple semi-empirical approximation for bond energy

    International Nuclear Information System (INIS)

    Jorge, F.E.; Giambiagi, M.; Giambiagi, M.S. de.

    1985-01-01

    A simple semi-empirical expression for bond energy, related with a generalized bond index, is proposed and applied within the IEH framework. The correlation with experimental data is good for the intermolecular bond energy of base pairs of nucleic acids and other hydrogen bonded systems. The intramolecular bond energies for a sample of molecules containing typical bonds and for hydrides are discussed. The results are compared with those obtained by other methods. (Author) [pt

  18. Evaluation of a New Nano-filled Bonding Agent for Bonding Orthodontic Brackets as Compared to a Conventional Bonding Agent: An in vitro Study

    Directory of Open Access Journals (Sweden)

    Sandesh S Pai

    2012-01-01

    Conclusion: Although both bonding agents provide clinically acceptable levels of bond strength, the technique to bond the nano-filled Prime and Bond NT is more cumbersome as compared to the Transbond XT material, which makes the latter a more popular choice in the clinical set up. If the application procedures for the Prime and Bond NT can be simplified then it could be a convenient option in the orthodontic practice.

  19. [{sup 11}C]S.L.(25.1188), a new radioligand to study the monoamine oxidase type B with PET: preclinical characterisation

    Energy Technology Data Exchange (ETDEWEB)

    Saba, W.; Valette, H.; Peyronneau, M.A.; Bramoulle, Y.; Coulon, C.; Dolle, F.; Bottlaender, M. [Service Hospitalier Frederic Joliot, IIBM/DSV, 91 - Orsay (France); Curet, O.; George, P. [Sanofi-Aventis, 92 - Bagneux (France)

    2008-02-15

    Introduction. - Monoamine oxidase (M.A.O.) is a flavin containing enzyme, that catalyzes the oxidative deamination of various amines and neurotransmitters. Two isoforms exist, M.A.O.-A and M.A.O.-B. Variations in M.A.O. activity may be associated to human disease such as Parkinson and Alzheimer disease. Few radiotracers have been developed for M.A.O. PET studies such as [{sup 11}C]deprenyl, an irreversible M.A.O.-B inhibitor. Recently an oxazolidinone derivative, S.L.- 25.1188 ((S)-5-methoxy-methyl-3-[6-(4,4,4-tri-fluoro butoxy)- benzo[d]isoxazol-3-yl]-oxazolidin-2-one), belonging to a new generation of selective and reversible M.A.O.-B inhibitors was developed and showed in vitro a high selectivity for M.A.O.B. [1]. The aim of this study was to characterize [{sup 11}C]S.L.- 25.1188 as radioligand for in vivo PET examination of M.A.O.-B. Materials and methods. - PET studies of the brain distribution were carried out in male Papio anubis baboons. Selectivity and reversibility of [{sup 11}C]S.L.-25.1188 binding for M.A.O.-B was assessed by pre-treatment or displacement experiments (30 min before and after tracer injection, respectively) using reference ligands for M.A.O.-B (deprenyl: 2 mg/kg i.v. and lazabemide: 0.5 mg/kg i.v.) or by displacement experiments using unlabelled S.L.-25.1188 (1 mg/kg, i.v., 30 min after tracer injection). Distribution volume (D.V.) was calculated using 2-tissue-compartment model. The saturable binding following pre-treatment with deprenyl was considered as the specific binding. Results. - After injection, [1{sup 1C}]S.L.-25.1188 presents a rapid phase of distribution in blood (about 5 min), followed by a elimination with T1/2 of 75 min. The Blood to plasma concentration ratio was constant during the experimentation (0.9 {+-} .04) consistent with a similar kinetic of [{sup 11}C]S.L.- 25.1188 in both blood and plasma. Metabolism analysis showed that [{sup 11}C]S.L.-25.1188 is stable in vivo. In the brain, uptake in different areas was

  20. Disorder-induced quantum bond percolation

    International Nuclear Information System (INIS)

    Nishino, Shinya; Katsuno, Shuji; Goda, Masaki

    2009-01-01

    We investigate the effects of off-diagonal disorder on localization properties in quantum bond percolation networks on cubic lattices, motivated by the finding that the off-diagonal disorder does not always enhance the quantum localization of wavefunctions. We numerically construct a diagram of the 'percolation threshold', distinguishing extended states from localized states as a function of two degrees of disorder, by using the level statistics and finite-size scaling. The percolation threshold increases in a characteristic way on increasing the disorder in the connected bonds, while it gradually decreases on increasing the disorder in the disconnected bonds. Furthermore, the exchange of connected and disconnected bonds induced by the disorder causes a dramatic change of the percolation threshold.

  1. Functional chiral hydrogen-bonded assemblies

    NARCIS (Netherlands)

    Mateos timoneda, Miguel

    2005-01-01

    In this thesis different aspects of functional hydrogen-bonded (double and tetrarosette) assemblies are described. The functions were inspired by naturally occurring mechanisms such as molecular recognition, supramolecular chirality and its origin, and biostrategies for the correct folding of

  2. On the photostability of the disulfide bond

    DEFF Research Database (Denmark)

    Stephansen, Anne Boutrup; Larsen, Martin Alex Bjørn; Klein, Liv Bærenholdt

    2014-01-01

    Photostability is an essential property of molecular building blocks of nature. Disulfides are central in the structure determination of proteins, which is in striking contradiction to the result that the S-S bond is a photochemically labile structural entity that cleaves to form free radicals upon...... on a sub 50 fs timescale without further ado. In a cyclic motif resembling the cysteine-disulfide bond in proteins, light can perturb the S-S bond to generate short-lived diradicaloid species, but the sulfur atoms are conformationally restricted by the ring that prevents the sulfur atoms from flying apart...... the photostability of disulfide-bonds must be ascribed a cyclic structural arrangement....

  3. 21 CFR 1.97 - Bonds.

    Science.gov (United States)

    2010-04-01

    ... the relabeling or other action necessary to bring the article into compliance with the act or rendering it other than a food, drug, device, or cosmetic, in such manner as is prescribed for such bond in...

  4. Space Shuttle OV-105 Subnominal Bond Investigation

    National Research Council Canada - National Science Library

    Gunn-Golkin, Anna E

    2005-01-01

    ... with Krylon 1201 Spray Starch or MS-143 Mold Release Agent. The research was accomplished by analyzing historical NASA documents, results of bond verification tests, peel tests, contamination tests and fabrication process anomaly tests.

  5. Engineering Performance of Polyurethane Bonded Aggregates

    Directory of Open Access Journals (Sweden)

    Haimin WU

    2017-08-01

    Full Text Available In this paper the engineering performance of polyurethane (PUR bonded aggregate were studied. The engineering performance, including compressive and flexural mechanical properties, void ratio, and coefficient of permeability were determined through laboratory tests. Moreover, the effects of two different curing conditions on the compressive strength properties of a PUR bonded aggregate were also evaluated. The compressive strengths of PUR bonded aggregates were found to be lower than that of conventional porous concrete, which is a commonly used cushion material. However, experimental results indicated a higher void ratio and coefficient of permeability, lower elasticity modulus, better toughness, and stronger adaptability to flexural deformation compared to porous concrete. Consequently, PUR bonded aggregate is a better solution than porous concrete when used as the cushion material of a geomembrane surface barrier for a high rock-fill dam.DOI: http://dx.doi.org/10.5755/j01.ms.23.2.15798

  6. Valuing Catastrophe Bonds Involving Credit Risks

    Directory of Open Access Journals (Sweden)

    Jian Liu

    2014-01-01

    Full Text Available Catastrophe bonds are the most important products in catastrophe risk securitization market. For the operating mechanism, CAT bonds may have a credit risk, so in this paper we consider the influence of the credit risk on CAT bonds pricing that is different from the other literature. We employ the Jarrow and Turnbull method to model the credit risks and get access to the general pricing formula using the Extreme Value Theory. Furthermore, we present an empirical pricing study of the Property Claim Services data, where the parameters in the loss function distribution are estimated by the MLE method and the default probabilities are deduced by the US financial market data. Then we get the catastrophe bonds value by the Monte Carlo method.

  7. Handbook of adhesive bonded structural repair

    CERN Document Server

    Wegman, Raymond F

    1992-01-01

    Provides repair methods for adhesive bonded and composite structures; identifies suitable materials and equipment for repairs; describes damage evaluation criteria and techniques, and methods of inspection before and after repair.

  8. 29 CFR 501.9 - Surety bond.

    Science.gov (United States)

    2010-07-01

    ... CONTRACTUAL OBLIGATIONS FOR TEMPORARY ALIEN AGRICULTURAL WORKERS ADMITTED UNDER SECTION 218 OF THE IMMIGRATION... demonstrating its ability to discharge financial obligations under the H-2A program. The original bond...

  9. Composite Laser Ceramics by Advanced Bonding Technology

    Science.gov (United States)

    Kamimura, Tomosumi; Honda, Sawao

    2018-01-01

    Composites obtained by bonding materials with the same crystal structure and different chemical compositions can create new functions that do not exist in conventional concepts. We have succeeded in bonding polycrystalline YAG and Nd:YAG ceramics without any interstices at the bonding interface, and the bonding state of this composite was at the atomic level, similar to the grain boundary structure in ceramics. The mechanical strength of the bonded composite reached 278 MPa, which was not less than the strength of each host material (269 and 255 MPa). Thermal conductivity of the composite was 12.3 W/mK (theoretical value) which is intermediate between the thermal conductivities of YAG and Nd:YAG (14.1 and 10.2 W/mK, respectively). Light scattering cannot be detected at the bonding interface of the ceramic composite by laser tomography. Since the scattering coefficients of the monolithic material and the composite material formed by bonding up to 15 layers of the same materials were both 0.10%/cm, there was no occurrence of light scattering due to the bonding. In addition, it was not detected that the optical distortion and non-uniformity of the refractive index variation were caused by the bonding. An excitation light source (LD = 808 nm) was collimated to 200 μm and irradiated into a commercial 1% Nd:YAG single crystal, but fracture damage occurred at a low damage threshold of 80 kW/cm2. On the other hand, the same test was conducted on the bonded interface of 1% Nd:YAG-YAG composite ceramics fabricated in this study, but it was not damaged until the excitation density reached 127 kW/cm2. 0.6% Nd:YAG-YAG composite ceramics showed high damage resistance (up to 223 kW/cm2). It was concluded that composites formed by bonding polycrystalline ceramics are ideal in terms of thermo-mechanical and optical properties. PMID:29425152

  10. Textural and mechanical characterization of C-S-H gels from hydration of synthetic T1-C{sub 3}S, {beta}-C{sub 2}S and their blends; Caracterizacion textural y mecanica de geles C-S-H formados en la hidratacion de muestras sinteticas T1-C{sub 3}S, {beta}-C{sub 2}S y sus mezclas

    Energy Technology Data Exchange (ETDEWEB)

    Goni, S.; Guerrero, A.; Puertas, F.; Hernandez, M. S.; Palacios, M.; Dolado, J. S.; Zhu, W.; Howind, T.

    2011-07-01

    The textural and mechanical characterization of C-S-H gels formed from the hydration of pure T1-C{sub 3}S, {beta}-C{sub 2}S and their blends are studied by Nitrogen sorption and nano indentation experiments. The surface area and nano porosity of C-S-H gels formed from the hydration of {beta}-C{sub 2}S and the 30-70 (T1-C{sub 3}S and {beta}-C{sub 2}S mixture) are higher than those from hydration of T1-C{sub 3}S, and 70-30, with the difference decreasing with hydration age. Such changes are well supported by findings of nano indentation study, which shows the greater relative volume of C-S-H phases with lower densities in the {beta}-C{sub 2}S and the 30-70 pastes. With the increase in hydration age, the relative volume of C-S-H phases with higher densities increased at the expenses of those with lower density. Important quantitative correlations were found among these textural characteristics and the mean chain length, determined from {sup 2}9Si magic-angle-spinning (MAS) NMR, of the C-S-H gels. (Author) 36 refs.

  11. Managing sovereign credit risk in bond portfolios

    OpenAIRE

    Bruder, Benjamin; Hereil, Pierre; Roncalli, Thierry

    2011-01-01

    With the recent development of the European debt crisis, traditional index bond management has been severely called into question. We focus here on the risk issues raised by the classical market-capitalization weighting scheme. We propose an approach to properly measure sovereign credit risk in a fixed-income portfolio. For that, we assume that CDS spreads follow a SABR process and we derive a sovereign credit risk measure based on CDS spreads and duration of portfolio bonds. We then consider...

  12. Expectations, Bond Yields and Monetary Policy

    DEFF Research Database (Denmark)

    Chun, Albert Lee

    2011-01-01

    expectations about inflation, output growth, and the anticipated path of monetary policy actions contain important information for explaining movements in bond yields. Estimates from a forward-looking monetary policy rule suggest that the central bank exhibits a preemptive response to inflationary expectations...... of this type may provide traders and policymakers with a new set of tools for formally assessing the reaction of bond yields to shifts in market expectations...

  13. A Global Stock and Bond Model

    OpenAIRE

    Connor, Gregory

    1996-01-01

    Factor models are now widely used to support asset selection decisions. Global asset allocation, the allocation between stocks versus bonds and among nations, usually relies instead on correlation analysis of international equity and bond indexes. It would be preferable to have a single integrated framework for both asset selection and asset allocation. This framework would require a factor model applicable at an asset or country level, as well as at a global level,...

  14. Testing Bonds Between Brittle And Ductile Films

    Science.gov (United States)

    Wheeler, Donald R.; Ohsaki, Hiroyuki

    1989-01-01

    Simple uniaxial strain test devised to measure intrinsic shear strength. Brittle film deposited on ductile stubstrate film, and combination stretched until brittle film cracks, then separates from substrate. Dimensions of cracked segments related in known way to tensile strength of brittle film and shear strength of bond between two films. Despite approximations and limitations of technique, tests show it yields semiquantitative measures of bond strengths, independent of mechanical properties of substrates, with results reproducible with plus or minus 6 percent.

  15. Automatic centring and bonding of lenses

    Science.gov (United States)

    Krey, Stefan; Heinisch, J.; Dumitrescu, E.

    2007-05-01

    We present an automatic bonding station which is able to center and bond individual lenses or doublets to a barrel with sub micron centring accuracy. The complete manufacturing cycle includes the glue dispensing and UV curing. During the process the state of centring is continuously controlled by the vision software, and the final result is recorded to a file for process statistics. Simple pass or fail results are displayed to the operator at the end of the process.

  16. Equity Volatility and Corporate Bond Yields

    OpenAIRE

    John Y. Campbell; Glen B. Taksler

    2002-01-01

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

  17. Determinants Of Ori001 Type Government Bond

    OpenAIRE

    Yulius, Yosandi

    2011-01-01

    The need to build a strong bond market is amenable, especially after the 1997 crises. This paper analyzes the influence of deposit interest rate, foreign exchange rates, and Composite Stock Price Index on yield-to-maturity of Bond Series Retail ORI001, employing monthly data from Bloomberg information service, 2006(8) to 2008(12), using Generalized Autoregressive Conditional Heteroscedasticity type models. It finds the evidence that deposit interest rate and exchange rate have positive signif...

  18. The chemical bond as an emergent phenomenon.

    Science.gov (United States)

    Golden, Jon C; Ho, Vinh; Lubchenko, Vassiliy

    2017-05-07

    We first argue that the covalent bond and the various closed-shell interactions can be thought of as symmetry broken versions of one and the same interaction, viz., the multi-center bond. We use specially chosen molecular units to show that the symmetry breaking is controlled by density and electronegativity variation. We show that the bond order changes with bond deformation but in a step-like fashion, regions of near constancy separated by electronic localization transitions. These will often cause displacive transitions as well so that the bond strength, order, and length are established self-consistently. We further argue on the inherent relation of the covalent, closed-shell, and multi-center interactions with ionic and metallic bonding. All of these interactions can be viewed as distinct sectors on a phase diagram with density and electronegativity variation as control variables; the ionic and covalent/secondary sectors are associated with on-site and bond-order charge density wave, respectively, the metallic sector with an electronic fluid. While displaying a contiguity at low densities, the metallic and ionic interactions represent distinct phases separated by discontinuous transitions at sufficiently high densities. Multi-center interactions emerge as a hybrid of the metallic and ionic bond that results from spatial coexistence of delocalized and localized electrons. In the present description, the issue of the stability of a compound is that of the mutual miscibility of electronic fluids with distinct degrees of electron localization, supra-atomic ordering in complex inorganic compounds coming about naturally. The notions of electronic localization advanced hereby suggest a high throughput, automated procedure for screening candidate compounds and structures with regard to stability, without the need for computationally costly geometric optimization.

  19. Pressure bonding molybdenum alloy (TZM) to reaction-bonded silicon nitride

    International Nuclear Information System (INIS)

    Huffsmith, S.A.; Landingham, R.L.

    1978-01-01

    Topping cycles could boost the energy efficiencies of a variety of systems by using what is now waste heat. One such topping cycle uses a ceramic helical expander and would require that a reaction-bonded silicon nitride (RBSN) rotor be bonded to a shaft of TZM (Mo-0.5 wt % Ti-0.08 wt % Zr). Coupon studies show that TZM can be bonded to RBSN at 1300 0 C and 69 MPa if there is an interlayer of MoSi 2 . A layer of finely ground (10 μm) MoSi 2 facilitates bond formation and provides a thicker bond interface. The hardness and grain structure of the TZM and RBSN were not affected by the temperature and pressure required to bond the coupons

  20. Evaluation of the BD Vacutainer Plus Urine C&S Preservative Tubes compared with nonpreservative urine samples stored at 4°C and room temperature.

    Science.gov (United States)

    Eisinger, Stephen W; Schwartz, Matthew; Dam, Lisa; Riedel, Stefan

    2013-09-01

    The stability of urine specimens submitted for culture remains a challenge for many laboratories because of delays in specimen transport. We evaluated the usefulness of BD Vacutainer Plus Urine C&S Preservative Tube in ensuring specimen stability. Clinical urine specimens collected in sterile collection cups (n = 110) were plated onto sheep blood and MacConkey agar following standard laboratory procedures guidelines. Thereafter, specimens were divided into 3 storage conditions: nonpreservative, refrigerated; nonpreservative, room temperature (RT); BD Vacutainer Plus Urine C&S Preservative Tube, RT. For each sample type, additional cultures were set up at 2, 4, 24, and 48 hours. Initially, 18 specimens had no growth, 32 showed mixed skin flora, and 60 yielded at least 1 uropathogen. Increased colony counts of uropathogens were observed for nonpreserved urine samples stored at RT; these changes were statistically significant. Minor differences between refrigerated urine samples and BD Vacutainer Plus Urine C&S Preservative Tube samples were seen but were not statistically significant. The use of preservative-containing collection tubes is desirable to ensure specimen stability when prompt processing or refrigeration is not feasible.

  1. Relationship between thin-film bond strength as measured by a scratch test, and indentation hardness for bonding agents.

    Science.gov (United States)

    Kusakabe, Shusuke; Rawls, H Ralph; Hotta, Masato

    2016-03-01

    To evaluate thin-film bond strength between a bonding agent and human dentin, using a scratch test, and the characteristics and accuracy of measurement. One-step bonding agents (BeautiBond; Bond Force; Adper Easy Bond; Clearfil tri-S Bond) and two-step bonding agents (Cleafil SE Bond; FL-Bond II) were investigated in this study. Flat dentin surfaces were prepared for extracted human molars. The dentin surfaces were ground and bonding agents were applied and light cured. The thin-film bond strength test of the specimens was evaluated by the critical load at which the coated bonding agent failed and dentin appeared. The scratch mark sections were then observed under a scanning electron microscope. Indentation hardness was evaluated by the variation in depth under an applied load of 10gf. Data were compared by one-way ANOVA with the Scheffé's post hoc multiple comparison test (pstrength and indentation hardness were analyzed using analysis of correlation and covariance. The thin-film bond strength of two-step bonding agents were found to be significantly higher than that of one-step bonding agents with small standard deviations. Scratch marks consistently showed adhesive failure in the vicinity of the bonding agent/dentin interface. The indentation hardness showed a trend that two-step bonding agents have greater hardness than one-step bonding agents. A moderately significant correlation (r(2)=0.31) was found between thin-film bond strength and indentation hardness. Thin-film bond strength test is a valid and reliable means of evaluating bond strength in the vicinity of the adhesive interface and is more accurate than other methods currently in use. Further, the thin-film bond strength is influenced by the hardness of the cued bonding agent. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  2. Dilemmas in zirconia bonding: A review

    Directory of Open Access Journals (Sweden)

    Obradović-Đuričić Kosovka

    2013-01-01

    Full Text Available This article presents a literature review on the resin bond to zirconia ceramic. Modern esthetic dentistry has highly recognized zirconia, among other ceramic materials. Biocompatibility of zirconia, chemical and dimensional stability, excellent mechanical properties, all together could guarantee optimal therapeutical results in complex prosthodontic reconstruction. On the other hand, low thermal degradation, aging of zirconia as well as problematic bonding of zirconia framework to dental luting cements and tooth structures, opened the room for discussion concerning their clinical durability. The well known methods of mechanical and chemical bonding used on glass-ceramics are not applicable for use with zirconia. Therefore, under critical clinical situations, selection of the bonding mechanism should be focused on two important points: high initial bond strength value and long term bond strength between zirconia-resin interface. Also, this paper emphases the use of phosphate monomer luting cements on freshly air-abraded zirconia as the simplest and most effective way for zirconia cementation procedure today.

  3. The diffusion bonding of advanced material

    International Nuclear Information System (INIS)

    Khan, T.I.

    2001-01-01

    As a joining process diffusion bonding has been used since early periods, and artifacts have been found which date back to 3000 years. However, over the last 20 years this joining process has been rediscovered and research has been carried out to understand the mechanisms of the process, and the application of the technique to advanced materials. This paper will review some of the reasons to why diffusion bonding may be preferred over other more conventional welding processes to join advanced alloy systems. It also describes in brief the different types of bonding processes, namely, solid-state and liquid phase bonding techniques. The paper demonstrates the application of diffusion bonding processes to join a range of dissimilar materials for instance: oxide dispersion strengthened superalloys, titanium to duplex stainless steels and engineering ceramics such as Si/sub 3/N/sub 4/ to metal alloys. The research work highlights the success and limitations of the diffusion bonding process and is based on the experience of the author and his colleagues. (author)

  4. Bonding silicon nitride using glass-ceramic

    International Nuclear Information System (INIS)

    Dobedoe, R.S.

    1995-01-01

    Silicon nitride has been successfully bonded to itself using magnesium-aluminosilicate glass and glass-ceramic. For some samples, bonding was achieved using a diffusion bonder, but in other instances, following an initial degassing hold, higher temperatures were used in a nitrogen atmosphere with no applied load. For diffusion bonding, a small applied pressure at a temperature below which crystallisation occurs resulted in intimate contact. At slightly higher temperatures, the extent of the reaction at the interface and the microstructure of the glass-ceramic joint was highly sensitive to the bonding temperature. Bonding in a nitrogen atmosphere resulted in a solution-reprecipitation reaction. A thin layer of glass produced a ''dry'', glass-free joint, whilst a thicker layer resulted in a continuous glassy join across the interface. The chromium silicide impurities within the silicon nitride react with the nucleating agent in the glass ceramic, which may lead to difficulty in producing a fine glass-ceramic microstructure. Slightly lower temperatures in nitrogen resulted in a polycrystalline join but the interfacial contact was poor. It is hoped that one of the bonds produced may be developed to eventually form part of a graded joint between silicon nitride and a high temperature nickel alloy. (orig.)

  5. Thai students' mental model of chemical bonding

    Science.gov (United States)

    Sarawan, Supawadee; Yuenyong, Chokchai

    2018-01-01

    This Research was finding the viewing about concept of chemical bonding is fundamental to subsequent learning of various other topics related to this concept in chemistry. Any conceptions about atomic structures that students have will be shown their further learning. The purpose of this study is to interviews conceptions held by high school chemistry students about metallic bonding and to reveal mental model of atomic structures show according to the educational level. With this aim, the questionnaire prepared making use of the literature and administered for analysis about mental model of chemical bonding. It was determined from the analysis of answers of questionnaire the 10th grade, 11th grade and 12th grade students. Finally, each was shown prompts in the form of focus cards derived from curriculum material that showed ways in which the bonding in specific metallic substances had been depicted. Students' responses revealed that learners across all three levels prefer simple, realistic mental models for metallic bonding and reveal to chemical bonding.

  6. The social life of bonding theory.

    Science.gov (United States)

    Crouch, M; Manderson, L

    1995-09-01

    'Bonding' as a crucial factor of the early post-partum entered obstetric and paediatric practice after the publication of Maternal and Infant Bonding in 1976 by Klaus and Kennell. The concept has held its place since, as witnessed by medical textbook accounts of it, and the perception of 'instantaneous bonding' as a vital component of the ideal birth experience has dominated media representations of childbirth and, until very recently, feminist writing. Only during the last few years has this literature taken into account research findings concerning the guilt and anxiety experienced by women whose expectations regarding 'bonding' are not realised. While it is now generally acknowledged that maternal attachment develops over an extended period of time, 'bonding' as used extensively in both popular and scientific literature conflates a wide range of meanings and blurs the boundaries between process and outcome. This facilitates the entry of ideological elements into a field which is, by its very nature, deeply significant for human experience. We therefore argue for a continuing critical appraisal of the role of 'bonding' in both general and scientific research.

  7. Composite Bonding to Stainless Steel Crowns Using a New Universal Bonding and Single-Bottle Systems

    OpenAIRE

    Mohammad Ali Hattan; Sharat Chandra Pani; Mohammad AlOmari

    2013-01-01

    Aim. The aim of this study is to evaluate the shear bond strength of nanocomposite to stainless steel crowns using a new universal bonding system. Material and Methods. Eighty (80) stainless steel crowns (SSCs) were divided into four groups (20 each). Packable nanocomposite was bonded to the lingual surface of the crowns in the following methods: Group A without adhesive (control group), Group B using a new universal adhesive system (Scotchbond Universal Adhesive, 3M ESPE, Seefeld, Germany), ...

  8. Evaluation of Shear Bond Strength of Orthodontic Brackets Bonded with Nano-Filled Composites

    OpenAIRE

    Chalipa, Javad; Akhondi, Mohammad Sadegh Ahmad; Arab, Sepideh; Kharrazifard, Mohammad Javad; Ahmadyar, Maryam

    2013-01-01

    Objectives: The purpose of this study was to evaluate the shear bond strength (SBS) of orthodontic brackets bonded with two types of nano-composites in comparison to a conventional orthodontic composite. Materials and Methods: Sixty extracted human first premolars were randomly divided into 3 groups each containing 20 teeth. In group I, a conventional orthodontic composite (Transbond XT) was used to bond the brackets, while two nano-composites (Filtek TM Supreme XT and AELITE Aesthetic Enamel...

  9. Comparison of shear bond strength of stainless steel brackets bonded with three light- cured adhesives

    Directory of Open Access Journals (Sweden)

    Zahra Minaei Basharik

    2015-09-01

    Full Text Available Introduction: The bonding process of the brackets to enamel has been a critical issue in orthodontic research. The purpose of this study was to evaluate the shear bond strength of 3 light-cured adhesives (transbond XT, Z250, light bond. Materials &Methods: In this study sixty extracted human premolars were collected and randomly divided into 3 test groups. All teeth were etched by 37% phosphoric acid. In first group brackets were bonded by Transbond XT adhesive, in group two brackets were bonded by Light bond adhesive and in third group were bonded by filtek Z250 composite. All of them were cured with Ortholux xt for 40 seconds.24 hours after thermocycling, Shear Bond Strength (SBS values of these brackets were recorded using a Universal Testing Machine. Adhesive Remnant Index (ARI scores were determined after the failure of the brackets, using Stereo Microscope the data were analyzed using ANOVA and Chi-square tests. Results: Mean shear bond strength of Transbond XT, light bond and Z250 were 28.9±2.25 MPa, 25.06±1.98 MPa and 26.8±2.57 MPa, respectively. No significant difference was observed in the SBS among the groups and a clinically acceptable SBS was found for the three adhesives. ARI scores were not significantly different between the various groups (P>0.05. Conclusion: This study showed that the Z250 can be used as light bond and transbond xt to bond orthodontic brackets and ARI and SBS scores were not significantly different.

  10. In vitro Comparative Evaluation of Tensile Bond Strength of 6(th), 7(th) and 8(th) Generation Dentin Bonding Agents.

    Science.gov (United States)

    Kamble, Suresh S; Kandasamy, Baburajan; Thillaigovindan, Ranjani; Goyal, Nitin Kumar; Talukdar, Pratim; Seal, Mukut

    2015-05-01

    Newer dentin bonding agents were developed to improve the quality of composite restoration and to reduce time consumption in its application. The aim of the present study was to evaluate tensile bond strength of 6(th), 7(th) and 8(th) generation bonding agents by in vitro method. Selected 60 permanent teeth were assigned into 20 in each group (Group I: 6(th) generation bonding agent-Adper SE plus 3M ESPE, Group II: 7(th) generation bonding agent-G-Bond GC Corp Japan and Group III: 8(th) generation dentin adhesives-FuturaBond, DC, Voco, Germany). With high-speed diamond disc, coronal dentin was exposed, and selected dentin bonding agents were applied, followed by composite restoration. All samples were saved in saline for 24 h and tensile bond strength testing was done using a universal testing machine. The obtained data were tabulated and statistically analyzed using ANOVA test. The tensile bond strength readings for 6(th) generation bonding agent was 32.2465, for 7(th) generation was 31.6734, and for 8(th)-generation dentine bonding agent was 34.74431. The highest tensile bond strength was seen in 8(th) generation bonding agent compared to 6(th) and 7(th) generation bonding agents. From the present study it can be conclude that 8(th) generation dentine adhesive (Futura DC, Voco, Germany) resulted in highest tensile bond strength compared to 6(th) (Adper SE plus, 3M ESPE) and 7(th) generation (G-Bond) dentin bonding agents.

  11. Association of bond, market, operational, and financial factors with multi-hospital system bond issues.

    Science.gov (United States)

    Carpenter, C E; McCue, M J; Hossack, J B

    2001-01-01

    Despite the growth of multi-hospital systems in the 1990s, their performance in the tax-exempt bond market has not been adequately evaluated. The purpose of this study is to compare bonds issued by multi-hospital systems to those issued by individual hospitals in terms of bond, market, operational, and financial characteristics. The study sample includes 2,078 newly issued, tax-exempt, revenue bonds between 1991 and 1997. The findings indicate that multi-hospital systems issued larger amounts of debt at a lower cost, were more likely to be insured, had higher debt service coverage and higher operating margins.

  12. Analysis of factors influencing the bond strength in roll bonding processes

    Science.gov (United States)

    Khaledi, Kavan; Wulfinghoff, Stephan; Reese, Stefanie

    2018-05-01

    Cold Roll Bonding (CRB) is recognized as an industrial technique in which the metal sheets are joined together in order to produce laminate metal composites. In this technique, a metallurgical bond resulting from severe plastic deformation is formed between the rolled metallic layers. The main objective of this paper is to analyse different factors which may affect the bond formation in rolling processes. To achieve this goal, first, an interface model is employed which describes both the bonding and debonding. In this model, the bond strength evolution between the metallic layers is calculated based on the film theory of bonding. On the other hand, the debonding process is modelled by means of a bilinear cohesive zone model. In the numerical section, different scenarios are taken into account to model the roll bonding process of metal sheets. The numerical simulation includes the modelling of joining during the roll bonding process followed by debonding in a Double Cantilever Beam (DCB) peeling test. In all simulations, the metallic layers are regarded as elastoplastic materials subjected to large plastic deformations. Finally, the effects of some important factors on the bond formation are numerically investigated.

  13. Diffusionless bonding of aluminum to type 304 stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Watson, R D

    1963-03-15

    High strength diffusionless bonds can be produced between 1S aluminum and oxidized 304 stainless steel by hot pressing and extrusion bonding. Both the hot pressing and extrusion bonding techniques have been developed to a point where consistently good bonds can be obtained. Although the bonding is performed at elevated temperatures (about 510{sup o}C) a protective atmosphere is not required to produce strong bonds. The aluminum-stainless steel bonded specimens can be used to join aluminum and stainless steel by conventional welding. Welding close to the bond zone does not appear to affect the integrity of the bond. The extrusion bonding technique is covered by Canadian patent 702,438 January 26, 1965 and the hot press bonding technique by Canadian patent application 904,548 June 6, 1964. (author)

  14. Diffusionless bonding of aluminum to type 304 stainless steel

    International Nuclear Information System (INIS)

    Watson, R.D.

    1963-03-01

    High strength diffusionless bonds can be produced between 1S aluminum and oxidized 304 stainless steel by hot pressing and extrusion bonding. Both the hot pressing and extrusion bonding techniques have been developed to a point where consistently good bonds can be obtained. Although the bonding is performed at elevated temperatures (about 510 o C) a protective atmosphere is not required to produce strong bonds. The aluminum-stainless steel bonded specimens can be used to join aluminum and stainless steel by conventional welding. Welding close to the bond zone does not appear to affect the integrity of the bond. The extrusion bonding technique is covered by Canadian patent 702,438 January 26, 1965 and the hot press bonding technique by Canadian patent application 904,548 June 6, 1964. (author)

  15. Renal cysteine conjugate C-S lyase mediated toxicity of halogenated alkenes in primary cultures of human and rat proximal tubular cells.

    Science.gov (United States)

    McGoldrick, Trevor A; Lock, Edward A; Rodilla, Vicente; Hawksworth, Gabrielle M

    2003-07-01

    Proximal tubular cells from human (HPT) and rat (RPT) kidneys were isolated, grown to confluence and incubated with S-(1,2-dichlorovinyl)- l-cysteine (DCVC), S-(1,2,2-trichlorovinyl)- l-cysteine (TCVC), S-(1,1,2,2-tetrafluoroethyl)- l-cysteine (TFEC) and S-(2-chloro-1,1-difluorethyl)- l-cysteine (CDFEC), the cysteine conjugates of nephrotoxicants. The cultures were exposed to the conjugates for 12, 24 and 48 h and the toxicity determined using the MTT assay. All four conjugates caused dose-dependent toxicity to RPT cells over the range 50-1,000 microM, the order of toxicity being DCVC>TCVC>TFEC=CDFEC. The inclusion of aminooxyacetic acid (AOAA; 250 microM), an inhibitor of pyridoxal phosphate-dependent enzymes such as C-S lyase, afforded protection, indicating that C-S lyase has a role in the bioactivation of these conjugates. In HPT cultures only DCVC caused significant time- and dose-dependent toxicity. Exposure to DCVC (500 microM) for 48 h decreased cell viability to 7% of control cell values, whereas co-incubation of DCVC (500 microM) with AOAA (250 microM) resulted in cell viability of 71%. Human cultures were also exposed to S-(1,2-dichlorovinyl)-glutathione (DCVG). DCVG was toxic to HPT cells, but the onset of toxicity was delayed compared with the corresponding cysteine conjugate. AOAA afforded almost complete protection from DCVG toxicity. Acivicin (250 microM), an inhibitor of gamma-glutamyl transferase (gamma-GT), partially protected against DCVG (500 microM)-induced toxicity at 48 h (5% viability and 53% viability in the absence and presence of acivicin, respectively). These results suggest that DCVG requires processing by gamma-GT prior to bioactivation by C-S lyase in HPT cells. The activity of C-S lyase, using TFEC as a substrate, and glutamine transaminase K (GTK) was measured in rat and human cells with time in culture. C-S lyase activity in RPT and HPT cells decreased to approximately 30% of fresh cell values by the time the cells reached

  16. Bond strength of compomers to dentin using acidic primers.

    Science.gov (United States)

    Tate, W H; You, C; Powers, J M

    1999-10-01

    To determine the in vitro bond strengths of seven compomer/bonding agent restorative systems to human dentin. Seven compomer/bonding agents were bonded to human dentin, stored in water at 37 degrees C for 24 hours, and debonded in tension. Bonding conditions were with and without phosphoric acid etching, with and without the use of combined primer/bonding agents, and under moist and wet bond interfaces. Without phosphoric acid etching, F2000/F2000 Compomer Primer/Adhesive and F2000/Single Bond Dental Adhesive System were less sensitive to dentin wetness. With moist dentin, bond strengths of Dyract/Prime & Bond 2.1, Dyract AP/Prime & Bond 2.1, Hytac/OSB light-curing, one-component bonding agent, F2000/Single Bond, and Freedom/STAE single component light-cured dentin/enamel adhesive system, were improved with phosphoric acid etching. Also, with moist dentin, the bond strength of F2000/F2000 Compomer Primer/Adhesive in the 3M Clicker dispensing system was higher without phosphoric acid etching, whereas bonds of Compoglass/Syntac Single-component were not affected by phosphoric acid etching. Bonding did not occur without primer/bonding agent, regardless of surface condition or use of phosphoric acid etching.

  17. Comparative evaluation of shear bond strength of metallic brackets bonded with two different bonding agents under dry conditions and with saliva contamination.

    Science.gov (United States)

    Khanehmasjedi, Mashallah; Naseri, Mohammad Ali; Khanehmasjedi, Samaneh; Basir, Leila

    2017-02-01

    This study compared the shear bond strength of metallic brackets bonded with Single Bond and Assure bonding agents under dry and saliva-contamination conditions. Sixty sound premolar teeth were selected, and stainless-steel brackets were bonded on enamel surfaces with Single Bond and Assure bonding agents under dry condition or with saliva contamination. Shear bond strength values of brackets were measured in a universal testing machine. The adhesive remnant index scores were determined after debonding of the brackets under a stereomicroscope. One-way analysis of variance (ANOVA) was used to analyze bond strength. Two-by-two comparisons were made with post hoc Tukey tests (pbrackets to tooth structure were 9.29±8.56 MPa and 21.25±8.93 MPa with the use of Assure resin bonding agent under saliva-contamination and dry conditions, respectively. These values were 10.13±6.69 MPa and 14.09±6.6 MPa, respectively, under the same conditions with the use of Single Bond adhesive. Contamination with saliva resulted in a significant decrease in the bond strength of brackets to tooth structure with the application of Assure adhesive resin (pbrackets to tooth structures. Contamination with saliva significantly decreased the bond strength of Assure bonding agent compared with dry conditions. Copyright © 2016. Published by Elsevier Taiwan LLC.

  18. Recent Advances in Ring-Opening Functionalization of Cycloalkanols by C-C σ-Bond Cleavage.

    Science.gov (United States)

    Wu, Xinxin; Zhu, Chen

    2018-06-01

    Cycloalkanols prove to be privileged precursors for the synthesis of distally substituted alkyl ketones and polycyclic aromatic hydrocarbons (PAHs) by virtue of cleavage of their cyclic C-C bonds. Direct functionalization of cyclobutanols to build up other chemical bonds (e. g., C-F, C-Cl, C-Br, C-N, C-S, C-Se, C-C, etc.) has been achieved by using the ring-opening strategy. Mechanistically, the C-C cleavage of cyclobutanols can be involved in two pathways: (a) transition-metal catalyzed β-carbon elimination; (b) radical-mediated 'radical clock'-type ring opening. The recent advances of our group for the ring-opening functionalization of tertiary cycloalkanols are described in this account. © 2018 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

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

    International Nuclear Information System (INIS)

    Yin, Zhifu; Zou, Helin; Sun, Lei; Xu, Shenbo; Qi, Liping

    2015-01-01

    Plastic planar nanofluidic chips are becoming increasingly important for biological and chemical applications. However, the majority of the present bonding methods for planar nanofluidic chips suffer from high dimension loss and low bonding strength. In this work, a novel thermal bonding technique based on O 2 plasma and ethanol treatment was proposed. With the assistance of O 2 plasma and ethanol, the PET (polyethylene terephthalate) planar nanofluidic chip can be bonded at a low bonding temperature of 50 °C. To increase the bonding rate and bonding strength, the O 2 plasma parameters and thermal bonding parameters were optimized during the bonding process. The tensile test indicates that the bonding strength of the PET planar nanofluidic chip can reach 0.954 MPa, while the auto-fluorescence test demonstrates that there is no leakage or blockage in any of the bonded micro- or nanochannels. (paper)

  20. Factors affecting the shear bond strength of metal and ceramic brackets bonded to different ceramic surfaces.

    Science.gov (United States)

    Abu Alhaija, Elham S J; Abu AlReesh, Issam A; AlWahadni, Ahed M S

    2010-06-01

    The aims of this study were to evaluate the shear bond strength (SBS) of metal and ceramic brackets bonded to two different all-ceramic crowns, IPS Empress 2 and In-Ceram Alumina, to compare the SBS between hydrofluoric acid (HFA), phosphoric acid etched, and sandblasted, non-etched all-ceramic surfaces. Ninety-six all-ceramic crowns were fabricated resembling a maxillary left first premolar. The crowns were divided into eight groups: (1) metal brackets bonded to sandblasted 9.6 per cent HFA-etched IPS Empress 2 crowns; (2) metal brackets bonded to sandblasted 9.6 per cent HFA-etched In-Ceram crowns; (3) ceramic brackets bonded to sandblasted 9.6 per cent HFA-etched IPS Empress 2 crowns; (4) ceramic brackets bonded to sandblasted 9.6 per cent HFA-etched In-Ceram crowns; (5) metal brackets bonded to sandblasted 37 per cent phosphoric acid-etched IPS Empress 2 crowns; (6) metal brackets bonded to sandblasted 37 per cent phosphoric acid-etched In-Ceram crowns; (7) metal brackets bonded to sandblasted, non-etched IPS Empress 2 crowns; and (8) metal brackets bonded to sandblasted, non-etched In-Ceram crowns. Metal and ceramic orthodontic brackets were bonded using a conventional light polymerizing adhesive resin. An Instron universal testing machine was used to determine the SBS at a crosshead speed of 0.1 mm/minute. Comparison between groups was performed using a univariate general linear model and chi-squared tests. The highest mean SBS was found in group 3 (120.15 +/- 45.05 N) and the lowest in group 8 (57.86 +/- 26.20 N). Of all the variables studied, surface treatment was the only factor that significantly affected SBS (P Empress 2 and In-Ceram groups.

  1. 27 CFR 26.68 - Bond, Form 2898-Beer.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Bond, Form 2898-Beer. 26... Liquors and Articles in Puerto Rico Bonds § 26.68 Bond, Form 2898—Beer. Where a brewer intends to withdraw, for purpose of shipment to the United States, beer of Puerto Rican manufacture from bonded storage in...

  2. FE modeling of Cu wire bond process and reliability

    NARCIS (Netherlands)

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

    2011-01-01

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

  3. Hydrogen Bond Dynamics in Aqueous Solutions: Ab initio Molecular ...

    Indian Academy of Sciences (India)

    Rate equation for the decay of CHB(t) · Definition of Hydrogen Bonds · Results of Molecular Dynamics · Dynamics of anion-water and water-water hydrogen bonds · Structural relaxation of anion-water & water-water H-bonds · Ab initio Molecular Dynamics : · Slide 14 · Dynamics of hydrogen bonds : CPMD results · Slide 16.

  4. 48 CFR 228.105 - Other types of bonds.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Other types of bonds. 228..., DEPARTMENT OF DEFENSE GENERAL CONTRACTING REQUIREMENTS BONDS AND INSURANCE Bonds 228.105 Other types of bonds... surety company are desired. [70 FR 8538, Feb. 22, 2005] ...

  5. 27 CFR 26.67 - Bond, Form 2897-Wine.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Bond, Form 2897-Wine. 26... Liquors and Articles in Puerto Rico Bonds § 26.67 Bond, Form 2897—Wine. Where a proprietor intends to withdraw, for purpose of shipment to the United States, wine of Puerto Rican manufacture from bonded...

  6. Vibrational polarizabilities of hydrogen-bonded water

    International Nuclear Information System (INIS)

    Torii, Hajime

    2013-01-01

    Highlights: ► Vibrational polarizabilities of hydrogen-bonded water are analyzed theoretically. ► Total vibrational polarizability is (at least) comparable to the electronic one. ► Molecular translations contribute to the vibrational polarizability below 300 cm −1 . ► Intermolecular charge fluxes along H bonds are induced by molecular translations. ► The results are discussed in relation to the observed dielectric properties. - Abstract: The vibrational polarizabilities and the related molecular properties of hydrogen-bonded water are analyzed theoretically, taking the case of (water) 30 clusters as an example case. It is shown that some off-diagonal dipole derivatives are large for the translations of incompletely hydrogen-bonded molecules, and this is reasonably explained by the scheme of intermolecular charge fluxes induced along hydrogen bonds. In total, because of these intermolecular charge fluxes, molecular translations give rise to the vibrational polarizability of 2.8–3.3 a 0 3 per molecule, which is as large as about 40% of the electronic polarizability, mainly in the frequency region below 300 cm −1 . Adding the contributions of the molecular rotations (librations) and the translation–rotation cross term, the total polarizability (electronic + vibrational) at ∼100 cm −1 is slightly larger than the double of that at >4000 cm −1 . The relation of these results to some observed time- and frequency-dependent dielectric properties of liquid water is briefly discussed

  7. Bond behavior of self compacting concrete

    Directory of Open Access Journals (Sweden)

    Ponmalar S.

    2018-03-01

    Full Text Available The success of an optimum design lies in the effective load transfer done by the bond forces at the steel-concrete interface. Self Compacting Concrete, is a new innovative concrete capable of filling intrinsic reinforcement and gets compacted by itself, without the need of external mechanical vibration. For this reason, it is replacing the conventional vibrated concrete in the construction industry. The present paper outlays the materials and methods adopted for attaining the self compacting concrete and describes about the bond behavior of this concrete. The bond stress-slip curve is similar in the bottom bars for both SCC and normal concrete whereas a higher bond stress and stiffness is experienced in the top and middle bars, for SCC compared to normal concrete. Also the interfacial properties revealed that the elastic modulus and micro-strength of interfacial transition zone [ITZ] were better on the both top and bottom side of horizontal steel bar in the SCC mixes than in normal vibrated concrete. The local bond strength of top bars for SCC is about 20% less than that for NC. For the bottom bars, however, the results were almost the same.

  8. Microshear bonding effectiveness of different dentin regions

    Directory of Open Access Journals (Sweden)

    Anelise F Montagner

    2015-01-01

    Full Text Available Aim: The aim of this in vitro study was to evaluate the influence of dentin surfaces with different tubule orientation on bond strength of a multimode adhesive system. Materials and Methods: Twenty human molars were selected and prepared in different ways in order to produce different dentin regions. The teeth were randomized (n = 5 according to the application modes of a multimode adhesive system (etch-and-rinse and self-etching and to the dentin region (occlusal and proximal - 1.5 mm depth from dentinoenamel junction. Cylindrical restorations were performed on dentin with a starch tube. The samples remained immersed in distilled water for 24 h and the microshear bond strength (μSBS test was performed. The μSBS values were expressed in MPa and analyzed with ANOVA and Tukey′s test (P < 0.05. Results: There was no significant difference in the bond strength values between the application modes of the adhesive system (P = 0.19; however, the dentin regions (P < 0.05 significantly affected the μSBS. The proximal dentin presented higher bond strength values than occlusal dentin. Conclusion: The dentin surfaces with different tubule orientation influenced the bonding effectiveness of the adhesive system tested.

  9. Types, risks and market of municipal bonds

    Directory of Open Access Journals (Sweden)

    Grujić Miloš

    2012-01-01

    Full Text Available Municipal bonds are issued by cities, municipalities or other local communities in order to quickly raise funds to cover current budget deficits, finish infrastructure projects for production and distribution of thermal energy, improve water supply, road construction, sports and recreation centers, schools or to fund such projects on more favorable terms than to borrow from banks. In this manner, necessary conditions are created for faster development of the real sector. The aim of this study is to evaluate the importance, possibilities and effects of the bond issue in the Republika Srpska aimed at securing funding for and development of local communities. Good examples that local government bonds enhance community development include capital markets in countries that have made the transition from the socialist system design, similar to the market of the Republika Srpska, like the Polish, Slovakian, Hungarian and Croatian markets. Issues of municipal bonds in the Republika Srpska succeeded mostly due to the workings of Investment-Development Bank of RS. However, it certainly shows that further high-quality municipal bonds could attract more interest from various institutional investors, especially mutual funds and insurance companies, and investors who are more risk-averse will be able to familiarize and inform themselves with the functioning of capital markets. In this manner, our capital market would confirm its essential role and thus become a generator of overall economic development of the Republika Srpska because it would enable more efficient collection and allocation of capital resources.

  10. CEMENT BONDED COMPOSITES – A MECHANICAL REVIEW

    Directory of Open Access Journals (Sweden)

    Stephan Frybort

    2008-05-01

    Full Text Available Over the last years promising cement bonded wood composites for structural purposes have evolved. Durability, toughness, high dimen-sional stability, resistance against environmental influences such as biodegradation or weathering but also availability of the raw material as well as economic factors are features which can make cement-bonded composites superior to conventionally bonded composites. This paper reviews the relationship of diverse parameters, including density and particle size on mechanical and physical properties of cement bonded composites, based on published sources from the last 60 years. For general and recent information about bonding mechanisms, compatibility and setting problems, determination and improvement of compatibility, the used raw materials as well as accelerators are discussed. The main part deals with failure mechanisms in connection with several production parameters. Furthermore, the influence of particle size and geometry, orientation of the particles, cement-wood ratio and the effect of accelerators and treatment of the particles on modulus of elasticity, modulus of rupture as well as thickness swelling are discussed.

  11. Significance of wood extractives for wood bonding.

    Science.gov (United States)

    Roffael, Edmone

    2016-02-01

    Wood contains primary extractives, which are present in all woods, and secondary extractives, which are confined in certain wood species. Extractives in wood play a major role in wood-bonding processes, as they can contribute to or determine the bonding relevant properties of wood such as acidity and wettability. Therefore, extractives play an immanent role in bonding of wood chips and wood fibres with common synthetic adhesives such as urea-formaldehyde-resins (UF-resins) and phenol-formaldehyde-resins (PF-resins). Extractives of high acidity accelerate the curing of acid curing UF-resins and decelerate bonding with alkaline hardening PF-resins. Water-soluble extractives like free sugars are detrimental for bonding of wood with cement. Polyphenolic extractives (tannins) can be used as a binder in the wood-based industry. Additionally, extractives in wood can react with formaldehyde and reduce the formaldehyde emission of wood-based panels. Moreover, some wood extractives are volatile organic compounds (VOC) and insofar also relevant to the emission of VOC from wood and wood-based panels.

  12. Amino Acid Patterns around Disulfide Bonds

    Directory of Open Access Journals (Sweden)

    Brett Drury

    2010-11-01

    Full Text Available Disulfide bonds provide an inexhaustible source of information on molecular evolution and biological specificity. In this work, we described the amino acid composition around disulfide bonds in a set of disulfide-rich proteins using appropriate descriptors, based on ANOVA (for all twenty natural amino acids or classes of amino acids clustered according to their chemical similarities and Scheffé (for the disulfide-rich proteins superfamilies statistics. We found that weakly hydrophilic and aromatic amino acids are quite abundant in the regions around disulfide bonds, contrary to aliphatic and hydrophobic amino acids. The density distributions (as a function of the distance to the center of the disulfide bonds for all defined entities presented an overall unimodal behavior: the densities are null at short distances, have maxima at intermediate distances and decrease for long distances. In the end, the amino acid environment around the disulfide bonds was found to be different for different superfamilies, allowing the clustering of proteins in a biologically relevant way, suggesting that this type of chemical information might be used as a tool to assess the relationship between very divergent sets of disulfide-rich proteins.

  13. Bond behavior of self compacting concrete

    Science.gov (United States)

    Ponmalar, S.

    2018-03-01

    The success of an optimum design lies in the effective load transfer done by the bond forces at the steel-concrete interface. Self Compacting Concrete, is a new innovative concrete capable of filling intrinsic reinforcement and gets compacted by itself, without the need of external mechanical vibration. For this reason, it is replacing the conventional vibrated concrete in the construction industry. The present paper outlays the materials and methods adopted for attaining the self compacting concrete and describes about the bond behavior of this concrete. The bond stress-slip curve is similar in the bottom bars for both SCC and normal concrete whereas a higher bond stress and stiffness is experienced in the top and middle bars, for SCC compared to normal concrete. Also the interfacial properties revealed that the elastic modulus and micro-strength of interfacial transition zone [ITZ] were better on the both top and bottom side of horizontal steel bar in the SCC mixes than in normal vibrated concrete. The local bond strength of top bars for SCC is about 20% less than that for NC. For the bottom bars, however, the results were almost the same.

  14. Microtensile bond strength of enamel after bleaching.

    Science.gov (United States)

    Lago, Andrea Dias Neves; Garone-Netto, Narciso

    2013-01-01

    To evaluate the bond strength of a composite resin to the bovine enamel bleached with 35% hydrogen peroxide. It was used an etching-and-rinse adhesive system employed immediately, 7 and 14 days after the bleaching. Twenty bovine teeth were randomly distributed into 4 groups (n = 5), 3 experimental and 1 control. G1: Unbleached + restoration 14 days after storage in artificial saliva (control); G2: Bleached + restoration immediately after bleaching; G3: Bleached + restoration 7 days after bleaching; G4: Bleached + restoration 14 days after bleaching. Their buccal enamel surfaces were flattened, and a 25 mm² (5 × 5 mm) area from each one of these regions was outlined so as to standardize the experimental region. Universal hybrid composite resin Filtek™Z350 was inserted into four layers of 1 mm each and photo-activated. The bond strength was quantitatively evaluated by a microtensile test (1.0 mm/min) 24 h after the restorative procedures. The failure mode was assessed through scanning electron microscopy (SEM). There was a significant reduction in the bond strength of the restored teeth immediately after the bleaching (G2). There were no significant differences in enamel bond strength between groups G1, G3, and G4. There was a predominance of adhesive and mixed (cohesive + adhesive) failure in all groups. The 7-day-period after the end of the bleaching with 35% hydrogen peroxide was enough to achieve the appropriate values of bond strength to the enamel.

  15. Bonding brackets to porcelain: in vitro study

    Directory of Open Access Journals (Sweden)

    Sant'Anna Eduardo Franzotti

    2002-01-01

    Full Text Available The aim of this research was to verify, in vitro, the effect of various porcelain surface treatments on the shear strength of orthodontic brackets bonded to porcelain and the mode of fracture after debonding. Eighty-eight samples of metallic supported feldspathic porcelain were randomly divided into four groups according to their surface preparation as follows: the porcelain was maintained intact (GI, roughened with a diamond bur (GII, etched with 10% hydrofluoric acid (GIII, or sandblasted with aluminum oxide (GIV. The specimens were treated with silane (Scothprime and brackets were bonded with Concise. Each sample was subjected to a shear load at a crosshead speed of 1 mm/min and a recording was made at the point of failure. Bond strengths, adequate to withstand the application of orthodontic forces, were achieved in all groups. The Kruskal-Wallis statistical test showed no significant differences in bond strength between the groups (p>0.05. However, many more porcelain fractures occurred on deglazed porcelain. This study indicates that with the appropriate material selection, the silane/composite procedure alone may be adequate for bonding.

  16. Mechanism of bonding and debonding using surface activated bonding method with Si intermediate layer

    Science.gov (United States)

    Takeuchi, Kai; Fujino, Masahisa; Matsumoto, Yoshiie; Suga, Tadatomo

    2018-04-01

    Techniques of handling thin and fragile substrates in a high-temperature process are highly required for the fabrication of semiconductor devices including thin film transistors (TFTs). In our previous study, we proposed applying the surface activated bonding (SAB) method using Si intermediate layers to the bonding and debonding of glass substrates. The SAB method has successfully bonded glass substrates at room temperature, and the substrates have been debonded after heating at 450 °C, in which TFTs are fabricated on thin glass substrates for LC display devices. In this study, we conducted the bonding and debonding of Si and glass in order to understand the mechanism in the proposed process. Si substrates are also successfully bonded to glass substrates at room temperature and debonded after heating at 450 °C using the proposed bonding process. By the composition analysis of bonding interfaces, it is clarified that the absorbed water on the glass forms interfacial voids and cause the decrease in bond strength.

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

    Science.gov (United States)

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

    2013-01-01

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

  18. AVE bond index in the H-bond of the Watson-Crick pairs

    International Nuclear Information System (INIS)

    Giambiagi, M.; Giambiagi, M.S. de; Barroso Filho, W.

    1981-01-01

    The normal Watson-Crick base pairs are treated as super-molecules. The properties of the electronic distribution along the N-H...Y bonds are studied in an all-valence-electrons calculation, through a bond index formula devised for non-orthogonal basis. Eletronic density diagrams of the adenine-uracil base pair are analysed. (Auhor) [pt

  19. Bond lengths and bond strengths in compounds of the 5f elements

    International Nuclear Information System (INIS)

    Zachariasen, W.H.

    1975-01-01

    The variation of bond length (D) with bond strength (S) in normal valence compounds of 3d, 4d, 5d-4f, and 6d-5f elements can be represented approximately as D(S)=D(0.5) F(S), where D(0.5) is a characteristic constant for a given bond and F(S) an empirical function which is the same for all bonds. A bond strength Ssub(ij)=ssub(ji) is assigned to the bond between atoms i and j such that Σsub(j) Ssub(ij)=vsub(i) and Σsub(i) Ssub(ij)=vsub(j), where vsub(i) and vsub(j) are the normal valences of the two atoms. The function F(S) decreases monotonically with increasing S, and is normalized to unity at S=0.5, so that the constant D(0.5) has the physical meaning of being the bond length adjusted to S=0.5. The method described above was used to interpret and systematize the experimental results on bond lengths in oxides, halides, and oxyhalides of the 5f elements. (U.S.)

  20. Unique Bond Breaking in Crystalline Phase Change Materials and the Quest for Metavalent Bonding.

    Science.gov (United States)

    Zhu, Min; Cojocaru-Mirédin, Oana; Mio, Antonio M; Keutgen, Jens; Küpers, Michael; Yu, Yuan; Cho, Ju-Young; Dronskowski, Richard; Wuttig, Matthias

    2018-05-01

    Laser-assisted field evaporation is studied in a large number of compounds, including amorphous and crystalline phase change materials employing atom probe tomography. This study reveals significant differences in field evaporation between amorphous and crystalline phase change materials. High probabilities for multiple events with more than a single ion detected per laser pulse are only found for crystalline phase change materials. The specifics of this unusual field evaporation are unlike any other mechanism shown previously to lead to high probabilities of multiple events. On the contrary, amorphous phase change materials as well as other covalently bonded compounds and metals possess much lower probabilities for multiple events. Hence, laser-assisted field evaporation in amorphous and crystalline phase change materials reveals striking differences in bond rupture. This is indicative for pronounced differences in bonding. These findings imply that the bonding mechanism in crystalline phase change materials differs substantially from conventional bonding mechanisms such as metallic, ionic, and covalent bonding. Instead, the data reported here confirm a recently developed conjecture, namely that metavalent bonding is a novel bonding mechanism besides those mentioned previously. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Bond strength tests between silicon wafers and duran tubes (fusion bonded fluidic interconnects)

    NARCIS (Netherlands)

    Fazal, I.; Berenschot, Johan W.; de Boer, J.H.; Jansen, Henricus V.; Elwenspoek, Michael Curt

    2005-01-01

    The fusion bond strength of glass tubes with standard silicon wafers is presented. Experiments with plain silicon wafers and those coated with silicon oxide and silicon nitride are presented. Results obtained are discussed in terms of homogeneity and strength of fusion bond. High pressure testing

  2. Comparison of Shear Bond Strength of RMGI and Composite Resin for Orthodontic Bracket Bonding

    Science.gov (United States)

    Yassaei, Soghra; Davari, Abdolrahim; Goldani Moghadam, Mahjobeh; Kamaei, Ahmad

    2014-01-01

    Objective: The aim of this study was to compare the shear bond strength (SBS) of resin modified glass ionomer (RMGI) and composite resin for bonding metal and ceramic brackets. Materials and Methods: Eighty-eight human premolars extracted for orthodontic purposes were divided into 4 groups (n=22). In groups 1 and 2, 22 metal and ceramic brackets were bonded using composite resin (Transbond XT), respectively. Twenty-two metal and ceramic brackets in groups 3 and 4, respectively were bonded using RMGI (Fuji Ortho LC, Japan). After photo polymerization, the teeth were stored in water and thermocycled (500 cycles between 5° and 55°). The SBS value of each sample was determined using a Universal Testing Machine. The amount of residual adhesive remaining on each tooth was evaluated under a stereomicroscope. Statistical analyses were done using two-way ANOVA. Results: RMGI bonded brackets had significantly lower SBS value compared to composite resin bonded groups. No statistically significant difference was observed between metal and ceramic brackets bonded with either the RMGI or composite resin. The comparison of the adhesive remnant index (ARI) scores between the groups indicated that the bracket failure mode was significantly different among groups (Porthodontic bonding purposes; however the provided SBS is still within the clinically acceptable range. PMID:25628663

  3. Bonding polycarbonate brackets to ceramic: : Effects of substrate treatment on bond strength

    NARCIS (Netherlands)

    Özcan, Mutlu; Vallittu, Pekka K.; Peltomäki, Timo; Huysmans, Marie-Charlotte; Kalk, Warner

    2004-01-01

    This study evaluated the effects of 5 different surface conditioning methods on the bond strength of polycarbonate brackets bonded to ceramic surfaces with resin based cement. Six disc-shaped ceramic specimens (feldspathic porcelain) with glazed surfaces were used for each group. The specimens were

  4. Chemical bond activation observed with an x-ray laser

    International Nuclear Information System (INIS)

    Beye, Martin; Öberg, Henrik; Xin, Hongliang

    2016-01-01

    The concept of bonding and anti-bonding orbitals is fundamental in chemistry. The population of those orbitals and the energetic difference between the two reflect the strength of the bonding interaction. Weakening the bond is expected to reduce this energetic splitting, but the transient character of bond-activation has so far prohibited direct experimental access. Lastly, we apply time-resolved soft X-ray spectroscopy at a free-electron laser to directly observe the decreased bonding–anti-bonding splitting following bond-activation using an ultra short optical laser pulse.

  5. Diversification through Catastrophe Bonds: Lessons from the Subprime Financial Crisis

    OpenAIRE

    Peter Carayannopoulos; M Fabricio Perez

    2015-01-01

    Are catastrophe bonds (CAT bonds) zero-beta investments? Are they a valuable new source of diversification for investors? We study these questions by analysing the dynamic relations of CAT bond returns and the returns of the stock, corporate bond and government bond markets. Our multivariate GARCH model results provide evidence that CAT bonds are zero-beta assets only in non-crisis periods. We document that CAT bonds were not immune to the effects of the recent financial crisis. With the coll...

  6. Signal analysis approach to ultrasonic evaluation of diffusion bond quality

    International Nuclear Information System (INIS)

    Thomas, Graham; Chinn, Diane

    1999-01-01

    Solid state bonds like the diffusion bond are attractive techniques for joining dissimilar materials since they are not prone to the defects that occur with fusion welding. Ultrasonic methods can detect the presence of totally unbonded regions but have difficulty sensing poor bonded areas where the substrates are in intimate contact. Standard ultrasonic imaging is based on amplitude changes in the signal reflected from the bond interface. Unfortunately, amplitude alone is not sensitive to bond quality. We demonstrated that there is additional information in the ultrasonic signal that correlates with bond quality. In our approach, we interrogated a set of dissimilar diffusion bonded samples with broad band ultrasonic signals. The signals were digitally processed and the characteristics of the signals that corresponded to bond quality were determined. These characteristics or features were processed with pattern recognition algorithms to produce predictions of bond quality. The predicted bond quality was then compared with the destructive measurement to assess the classification capability of the ultrasonic technique

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

    Directory of Open Access Journals (Sweden)

    Grace Syavira Suryabrata

    2006-03-01

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

  8. Investigation of ball bond integrity for 0.8 mil (20 microns) diameter gold bonding wire on low k die in wire bonding technology

    Science.gov (United States)

    Kudtarkar, Santosh Anil

    Microelectronics technology has been undergoing continuous scaling to accommodate customer driven demand for smaller, faster and cheaper products. This demand has been satisfied by using novel materials, design techniques and processes. This results in challenges for the chip connection technology and also the package technology. The focus of this research endeavor was restricted to wire bond interconnect technology using gold bonding wires. Wire bond technology is often regarded as a simple first level interconnection technique. In reality, however, this is a complex process that requires a thorough understanding of the interactions between the design, material and process variables, and their impact on the reliability of the bond formed during this process. This research endeavor primarily focused on low diameter, 0.8 mil thick (20 mum) diameter gold bonding wire. Within the scope of this research, the integrity of the ball bond formed by 1.0 mil (25 mum) and 0.8 mil (20 mum) diameter wires was compared. This was followed by the evaluation of bonds formed on bond pads having doped SiO2 (low k) as underlying structures. In addition, the effect of varying the percentage of the wire dopant, palladium and bonding process parameters (bonding force, bond time, ultrasonic energy) for 0.8 mil (20 mum) bonding wire was also evaluated. Finally, a degradation empirical model was developed to understand the decrease in the wire strength. This research effort helped to develop a fundamental understanding of the various factors affecting the reliability of a ball bond from a design (low diameter bonding wire), material (low k and bonding wire dopants), and process (wire bonding process parameters) perspective for a first level interconnection technique, namely wire bonding. The significance of this research endeavor was the systematic investigation of the ball bonds formed using 0.8 mil (20 microm) gold bonding wire within the wire bonding arena. This research addressed low k

  9. Banks, Government Bonds, and Default: What do the Data Say?

    OpenAIRE

    Gennaioli, Nicola; Martin, Alberto; Rossi, Stefano

    2014-01-01

    We analyze holdings of public bonds by over 20,000 banks in 191 countries, and the role of these bonds in 20 sovereign defaults over 1998-2012. Banks hold many public bonds (on average 9% of their assets), particularly in less financially-developed countries. During sovereign defaults, banks increase their exposure to public bonds, especially large banks and when expected bond returns are high. At the bank level, bondholdings correlate negatively with subsequent lending during sovereign defau...

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

    Directory of Open Access Journals (Sweden)

    S Hamid Raji

    2011-01-01

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

  11. The halogen bond: Nature and applications

    Science.gov (United States)

    Costa, Paulo J.

    2017-10-01

    The halogen bond, corresponding to an attractive interaction between an electrophilic region in a halogen (X) and a nucleophile (B) yielding a R-X⋯B contact, found applications in many fields such as supramolecular chemistry, crystal engineering, medicinal chemistry, and chemical biology. Their large range of applications also led to an increased interest in their study using computational methods aiming not only at understanding the phenomena at a fundamental level, but also to help in the interpretation of results and guide the experimental work. Herein, a succinct overview of the recent theoretical and experimental developments is given starting by discussing the nature of the halogen bond and the latest theoretical insights on this topic. Then, the effects of the surrounding environment on halogen bonds are presented followed by a presentation of the available method benchmarks. Finally, recent experimental applications where the contribution of computational chemistry was fundamental are discussed, thus highlighting the synergy between the lab and modeling techniques.

  12. Bond return predictability in expansions and recessions

    DEFF Research Database (Denmark)

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

    We document that over the period 1953-2011 US bond returns are predictable in expansionary periods but unpredictable during recessions. This result holds in both in-sample and out-of-sample analyses and using both univariate regressions and combination forecasting techniques. A simulation study...... but negative in recessions. The results are also consistent with tests showing that the expectations hypothesis of the term structure holds in recessions but not in expansions. However, the results for bonds are in sharp contrast to results for stocks showing that stock returns are predictable in recessions...... but not in expansions. Thus, our results indicate that there is not a common predictive pattern of stock and bond returns associated with the state of the economy....

  13. Visualized Bond Scission in Mechanically Activated Polymers

    Institute of Scientific and Technical Information of China (English)

    Yuan Yuan; Yu-lan Chen

    2017-01-01

    Visualization and quantitative evaluation of covalent bond scission in polymeric materials are critical in understanding their failure mechanisms and improving the toughness and reliability of the materials.Mechano-responsive polymers with the ability of molecular-level transduction of force into chromism and luminescence have evoked major interest and experienced significant progress.In the current review,we highlight the recent achievements in covalent mechanochromic and mechanoluminescent polymers,leading to a bridge between macroscopic mechanical properties and microscopic bond scission events.After a general introduction concerning polymer mechanochemistry,various examples that illustrate the strategies of design and incorporation of functional and weak covalent bonds in polymers were presented,the mechanisms underlying the optical phenomenon were introduced and their potential applications as stress sensors were discussed.This review concludes with a comment on the opportunities and challenges of the field.

  14. Producción de A.C.S. y climatización de una vivienda unifamiliar con energía geotérmica

    OpenAIRE

    Martínez Doce, Rubén

    2014-01-01

    El objetivo de este proyecto fin de carrera es el de realizar un diseño de una instalación para la producción de agua caliente sanitaria (A.C.S.), climatización de las estancias y de una piscina cubierta, de una vivienda unifamiliar mediante energía geotérmica, con el fin de proporcionar un ahorro energético utilizando una energía limpia. Ingeniería Industrial Industria Ingeniaritza

  15. Enamel and dentin bond strength following gaseous ozone application.

    Science.gov (United States)

    Cadenaro, Milena; Delise, Chiara; Antoniollo, Francesca; Navarra, Ottavia Chiara; Di Lenarda, Roberto; Breschi, Lorenzo

    2009-08-01

    To evaluate the effects of gaseous ozone application on enamel and dentin bond strength produced by two self-etching adhesive systems. The shear bond strength test was conducted to assess adhesion on enamel (protocol 1), while the microtensile bond strength test was performed on dentin (protocol 2). Protocol 1: 96 bovine incisors were randomly divided into 4 groups, and enamel surfaces were bonded in accordance with the following treatments: (1E) ozone + Clearfil Protect Bond; (2E) Clearfil Protect Bond (control); (3E) ozone + Xeno III; (4E) Xeno III (control). Ozone gas was applied for 80 s. Shear bond strength was measured with a universal testing machine. Protocol 2: 40 noncarious human molars were selected. Middle/deep dentin was exposed and bonded in accordance with the following treatments: (1D) ozone+Clearfil Protect Bond; (2D) Clearfil Protect Bond (control); (3D) ozone+Xeno III (4D) Xeno III (control). Four-mm-thick buildups were built on the adhesives, then specimens were sectioned in accordance with the nontrimming technique. Specimens were stressed until failure occurred, and failure modes were analyzed. Shear bond and microtensile bond strength data were analyzed using two-way ANOVA and Tukey's post-hoc test. No statistical differences were found between ozone treated specimens and controls, neither on enamel nor on dentin irrespective of the tested adhesive. Clearfil Protect Bond showed higher bond strength to enamel than Xeno III, irrespective of the ozone treatment (p enamel and dentin bond strength.

  16. Stock vs. Bond Yields, and Demographic Fluctuations

    DEFF Research Database (Denmark)

    Gozluklu, Arie; Morin, Annaïg

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

  17. X-ray diffraction and chemical bonding

    International Nuclear Information System (INIS)

    Bats, J.W.

    1976-01-01

    Chemical bonds are investigated in sulfamic acid (H 3 N-SO 3 ), sodium sulfonlate dihydrate (H 2 NC 6 H 4 SO 3 Na.2H 2 O), 2,5-dimercaptothiadiazole (HS-C 2 N 2 S-SH), sodium cyanide dihydrate (NaCN.2H 2 O), sodium thiocyanate (NaSCN) and ammonium thiocyanate (NH 4 SCN) by X-ray diffraction, and if necessary completed with neutron diffraction. Crystal structures and electron densities are determined together with bond length and angles. Also the effects of thermal motion are discussed

  18. Limits to Arbitrage in Sovereign Bonds

    DEFF Research Database (Denmark)

    Pelizzon, Loriana; Subrahmanyam, Marti G.; Tomio, Davide

    the recent Euro-zone sovereign bond crisis and, surprisingly, find that: (i) even though the futures market leads the cash market in price discovery, the cash market leads the futures market in liquidity discovery, i.e., the willingness of market makers to trade (measured by market depth and bid-ask spread......), and (ii) the liquidity in the cash market, and not in the futures market, has a significant impact on the basis between the price of the futures contract and that of the cash bond that is cheapest to deliver. However, the interventions of the European Central Bank (ECB), during the Euro-zone crisis, had...

  19. Adhesive bonding using variable frequency microwave energy

    Science.gov (United States)

    Lauf, Robert J.; McMillan, April D.; Paulauskas, Felix L.; Fathi, Zakaryae; Wei, Jianghua

    1998-01-01

    Methods of facilitating the adhesive bonding of various components with variable frequency microwave energy are disclosed. The time required to cure a polymeric adhesive is decreased by placing components to be bonded via the adhesive in a microwave heating apparatus having a multimode cavity and irradiated with microwaves of varying frequencies. Methods of uniformly heating various articles having conductive fibers disposed therein are provided. Microwave energy may be selectively oriented to enter an edge portion of an article having conductive fibers therein. An edge portion of an article having conductive fibers therein may be selectively shielded from microwave energy.

  20. Money and bonds: an equivalence theorem

    OpenAIRE

    Narayana R. Kocherlakota

    2007-01-01

    This paper considers four models in which immortal agents face idiosyncratic shocks and trade only a single risk-free asset over time. The four models specify this single asset to be private bonds, public bonds, public money, or private money respectively. I prove that, given an equilibrium in one of these economies, it is possible to pick the exogenous elements in the other three economies so that there is an outcome-equivalent equilibrium in each of them. (The term ?exogenous variables? ref...

  1. Low-temperature Au/a-Si wafer bonding

    International Nuclear Information System (INIS)

    Jing, Errong; Xiong, Bin; Wang, Yuelin

    2011-01-01

    The Si/SiO 2 /Ti/Au–Au/Ti/a-Si/SiO 2 /Si bonding structure, which can also be used for the bonding of non-silicon material, was investigated for the first time in this paper. The bond quality test showed that the bond yield, bond repeatability and average shear strength are higher for this bonding structure. The interfacial microstructure analysis indicated that the Au-induced crystallization of the amorphous silicon process leads to big Si grains extending across the bond interface and Au filling the other regions of the bond interface, which result into a strong and void-free bond interface. In addition, the Au-induced crystallization reaction leads to a change in the IR images of the bond interface. Therefore, the IR microscope can be used to evaluate and compare the different bond strengths qualitatively. Furthermore, in order to verify the superiority of the bonding structure, the Si/SiO 2 /Ti/Au–a-Si/SiO 2 /Si (i.e. no Ti/Au layer on the a-Si surface) and Si/SiO 2 /Ti/Au–Au/Ti/SiO 2 /Si bonding structures (i.e. Au thermocompression bonding) were also investigated. For the Si/SiO 2 /Ti/Au–a-Si/SiO 2 /Si bonding structure, the poor bond quality is due to the native oxide layer on the a-Si surface, and for the Si/SiO 2 /Ti/Au–Au/Ti/SiO 2 /Si bonding structure, the poor bond quality is caused by the wafer surface roughness which prevents intimate contact and limits the interdiffusion at the bond interface.

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

    International Nuclear Information System (INIS)

    Yasuyama, Masanori; Ogawa, Kazuhiro; Taka, Takao; Nakasuji, Kazuyuki; Nakao, Yoshikuni; Nishimoto, Kazutoshi.

    1996-01-01

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

  3. To Think and Watch the Evil: The Turn of the Screw as Cultural Reference in Television from Dark Shadows to C.S.I.

    Directory of Open Access Journals (Sweden)

    Anna Viola Sborgi

    2012-07-01

    Full Text Available Since its first publication, Henry James’s The Turn of the Screw (1898 has always haunted the imagination of artists (Benjamin Britten, Jack Clayton, Amenábar and has been widely used as a source for television narratives (Dan Curtis, US TV version starring Colin Firth, Tim Fywell. In serial productions, James’s story has been the object of extensive quotation and allusion, from the 1960 gothic soap opera Dark Shadows to the C.S.I. episode Turn of the Screw (Season 4, Episode 21. A milestone in literary history, the story now embodies a set of cultural references conveying different, complex meanings, which can only be disclosed in the light of contemporary forms of representing reality. The novella appeals to two apparently opposite tendencies in contemporary television: the morbid display of the real (C.S.I. and the quest for the supernatural (Buffy The Vampire Slayer, among others. A line can be traced from Dark Shadows, the show that pioneered the genre, to contemporary horror soaps about vampires and supernatural phenomena. This paper shows the ways in which James’ sophisticated novella makes its way through popular culture, and how its constant ambiguous, dilemmatic interplay between reality and imagination can be related to the double-sided drive of the contemporary public towards hyper-reality and the supernatural.

  4. Tensile bond strength of metal bracket bonding to glazed ceramic surfaces with different surface conditionings.

    Science.gov (United States)

    Akhoundi, Ms Ahmad; Kamel, M Rahmati; Hashemi, Sh Mahmood; Imani, M

    2011-01-01

    The objective of this study was to compare the tensile bond strength of metal brackets bonding to glazed ceramic surfaces using three various surface treatments. Forty two glazed ceramic disks were assigned to three groups. In the first and second groups the specimens were etched with 9.5% hydrofluoric acid (HFA). Subsequently in first group, ceramic primer and adhesive were applied, but in second group a bonding agent alone was used. In third group, specimens were treated with 35% phosphoric acid followed by ceramic primer and adhesive application. Brackets were bonded with light cure composites. The specimens were stored in distilled water in the room temperature for 24 hours and thermocycled 500 times between 5°C and 55°C. The universal testing machine was used to test the tensile bond strength and the adhesive remenant index scores between three groups was evaluated. The data were subjected to one-way ANOVA, Tukey and Kruskal-Wallis tests respectively. The tensile bond strength was 3.69±0.52 MPa forfirst group, 2.69±0.91 MPa for second group and 3.60±0.41 MPa for third group. Group II specimens showed tensile strength values significantly different from other groups (Ptensile bond strength.

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

    Directory of Open Access Journals (Sweden)

    Michael Wendler

    2016-07-01

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

  6. Effect of Delayed Bonding and Antioxidant Application on the Bond Strength to Enamel after Internal Bleaching.

    Science.gov (United States)

    Kılınç, Halil İbrahim; Aslan, Tuğrul; Kılıç, Kerem; Er, Özgür; Kurt, Gökmen

    2016-07-01

    This study evaluated the effect of delayed bonding and antioxidant application (AA, 10% sodium ascorbate) after internal bleaching (35% carbamide peroxide) on the shear bond strength of an adhesive cement to enamel. Eighty-four human maxillary central incisors were endodontically treated. The control group remained unbleached with no AA. Experimental groups were all internally bleached. The buccal enamel was finished and polished with metallographic paper to a refinement of #600, in order to obtain a 5-mm(2) flat bonding area. An adhesive cement (Clearfil Esthetic) was placed into a plastic tube with internal diameter of 3 mm and a 3-mm height and cured on the enamel. Bonding occurred either immediately after bleaching (group Im), a 7-day delay (group 7), or a 14-day delay (group 14), and half the specimens were treated with antioxidant application (groups Im-AA, 7-AA, and 14-AA). Shear bond strength testing was performed on a universal testing machine, and data were analyzed with ANOVA and Fisher test (5%). Delaying of bonding is a useful factor for enhancing shear bond strength (p adhesive cementation to enamel is recommended only when delayed 14 days, or delayed 7 days with sodium ascorbate application. © 2015 by the American College of Prosthodontists.

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

    Science.gov (United States)

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

    2016-01-01

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

  8. Tensile Bond Strength of Metal Bracket Bonding to Glazed Ceramic Surfaces With Different Surface Conditionings

    Directory of Open Access Journals (Sweden)

    M. Imani

    2011-12-01

    Full Text Available Objective: The objective of this study was to compare the tensile bond strength of metal brackets bonding to glazed ceramic surfaces using three various surface treatments.Materials and Methods: Forty two glazed ceramic disks were assigned to three groups. In the first and second groups the specimens were etched with 9.5% hydrofluoric acid (HFA. Subsequently in first group, ceramic primer and adhesive were applied, but in second group a bonding agent alone was used. In third group, specimens were treated with 35% phosphoric acid followed by ceramic primerand adhesive application. Brackets were bonded with light cure composites. The specimens were stored in distilled water in the room temperature for 24 hours and thermocycled 500 times between 5°C and 55°C. The universal testing machine was used to test the tensile bond strength and the adhesive remenant index scores between three groups was evaluated. The data were subjected to one-way ANOVA, Tukey and Kruskal-Wallis tests respectively.Results: The tensile bond strength was 3.69±0.52 MPa forfirst group, 2.69±0.91 MPa for second group and 3.60±0.41 MPa for third group. Group II specimens showed tensile strength values significantly different from other groups (P<0.01.Conclusion: In spite of limitations in laboratory studies it may be concluded that in application of Scotch bond multipurpose plus adhesive, phosphoric acid can be used instead of HFA for bonding brackets to the glazed ceramic restorations with enough tensile bond strength.

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

    Directory of Open Access Journals (Sweden)

    Ghazali Syamni

    2011-09-01

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

  10. Deriving inflation forecasts from government bond prices

    Directory of Open Access Journals (Sweden)

    Kožul Nataša

    2014-01-01

    Full Text Available In financial research and practice, it is widely accepted that nominal interest rates derived from the prices of various financial products of different maturities comprise of corresponding real interest rates and inflation. While extensive research has been conducted on the relationship between these three variables, estimation of their levels is still largely based on the industry surveys and market data. As this information only indicates the current expectations of interest rate and inflation movements over time, a number of caveats should be noted when interpreting such measures. In the US and the UK, where the government bond markets are the largest and most active, a comparative analysis between conventional government bonds and those whose yield is linked to inflation provides a measure of inflation expectations. However, as such analyses implicitly assume that investment in government bonds is virtually risk free, it is questionable whether the derived estimates are of any value in current economic conditions. Moreover, this approach cannot be generalized to other countries, where number of traded products from which any relationship between interest rates and inflation can be determined is limited and different economic conditions prevail. Thus, this paper aims to present an overview of the methodologies used to forecast inflation rates from government bond prices, drawing attention to the key assumptions and limitations of these approaches. The goal is to ascertain their accuracy, and thus their value in determining the real yields of various interest rate-linked products.

  11. Uus Bond on blond / Kaivo Kopli

    Index Scriptorium Estoniae

    Kopli, Kaivo

    2005-01-01

    Uus Bond on briti näitleja Daniel Craig, kes mängib 21. Bondi-filmis "Casino Royale", režissöör Martin Campbell. Lisatud eelmiste Bondide nimekiri koos nende filmide loeteluga ning näidiseid esemetest, mis Bondi filmides ümbritsevad

  12. METHOD AND ALLOY FOR BONDING TO ZIRCONIUM

    Science.gov (United States)

    McCuaig, F.D.; Misch, R.D.

    1960-04-19

    A brazing alloy can be used for bonding zirconium and its alloys to other metals, ceramics, and cermets, and consists of 6 to 9 wt.% Ni, 6 to 9 wn~.% Cr, Mo, or W, 0 to 7.5 wt.% Fe, and the balance Zr.

  13. One hundred years of Lewis Chemical Bond!

    Indian Academy of Sciences (India)

    2016-09-20

    Sep 20, 2016 ... Chemists knew how many electrons are there in each element and were also aware of stable electronic configurations. For example, 'inert gases' having. 8 electrons in the valence shell (now known as s and p orbitals) were very stable. Bonding in polar molecules, called electrovalent those days, such as ...

  14. [Resin-bonded fixed partial dentures

    NARCIS (Netherlands)

    Kreulen, C.M.; Creugers, N.H.J.

    2013-01-01

    A resin-bonded fixed partial denture is a prosthetic construction which can replace I or several teeth in an occlusal system and which comprises a pontic element which is adhesively attached to 1 or more abutment teeth. To compensate for the limited shear strength of the adhesive layer, the Jixed

  15. Decomposing European bond and equity volatility

    DEFF Research Database (Denmark)

    Christiansen, Charlotte

    The paper investigates volatility spillover from US and aggregate European asset markets into European national asset markets. A main contribution is that bond and equity volatilities are analyzed simultaneously. A new model belonging to the "volatilityspillover" family is suggested: The conditio...

  16. Bonding and structure of copper nitrenes.

    Science.gov (United States)

    Cundari, Thomas R; Dinescu, Adriana; Kazi, Abul B

    2008-11-03

    Copper nitrenes are of interest as intermediates in the catalytic aziridination of olefins and the amination of C-H bonds. However, despite advances in the isolation and study of late-transition-metal multiply bonded complexes, a bona fide structurally characterized example of a terminal copper nitrene has, to our knowledge, not been reported. In anticipation of such a report, terminal copper nitrenes are studied from a computational perspective. The nitrene complexes studied here are of the form (beta-diketiminate)Cu(NPh). Density functional theory (DFT), complete active space self-consistent-field (CASSCF) electronic structure techniques, and hybrid quantum mechanical/molecular mechanical (QM/MM) methods are employed to study such species. While DFT methods indicate that a triplet (S = 1) is the ground state, CASSCF calculations indicate that a singlet (S = 0) is the ground state, with only a small energy gap between the singlet and triplet. Moreover, the ground-state (open-shell) singlet copper nitrene is found to be highly multiconfigurational (i.e., biradical) and to possess a bent geometry about the nitrene nitrogen, contrasting with the linear nitrene geometry of the triplet copper nitrenes. CASSCF calculations also reveal the existence of a closed-shell singlet state with some degree of multiple bonding character for the copper-nitrene bond.

  17. Unexpected complications of bonded mandibular lingual retainers.

    NARCIS (Netherlands)

    Katsaros, C.; Livas, C.; Renkema, A.M.

    2007-01-01

    INTRODUCTION: The flexible spiral wire (FSW) retainer is the most frequently used type of fixed retainer bonded on all 6 anterior teeth. Our aim in this article was to demonstrate unexpected posttreatment changes in the labiolingual position of the mandibular anterior teeth associated with the use

  18. 78 FR 46528 - Surety Bond Guarantee Program

    Science.gov (United States)

    2013-08-01

    ... 2013, Public Law 112-239, 126 Stat. 1632: (1) Increasing the contract amount for which SBA is... remedies under contract law, the Act, and the regulations in this part, SBA is relieved of liability in...), including the provisions that increase the contract amounts for which SBA is authorized to guarantee bonds...

  19. Contingent convertible bonds as countercyclical capital measures

    Directory of Open Access Journals (Sweden)

    Francois Liebenberg

    2017-06-01

    Aim: The effectiveness of the CCB during contractions is not obvious. Contingent convertible (CoCo bonds – which are bond-like until triggered by a deterioration of a prescribed capital metric, at which point they convert into a form of equity – are explored as a supplementary countercyclical capital measure for such periods to establish whether or not they function effectively. Setting: The analysis is undertaken using global bank CoCo data, and then applied to South African banks. Methods: The Hodrick Prescott filter was applied to empirical historical data. Results: The CCB functions as a good countercyclical capital measure in times of economic expansion by absorbing losses and stabilising the capital base through equity issuance. Conclusion: The issuance of CoCo bonds – if their trigger mechanisms are designed correctly – may prove helpful to banks and the broader financial sector in times of economic contraction through the countercyclical capital properties that manifest through CoCo bonds under these economic conditions.

  20. Continuing Bonds after Suicide Bereavement in Childhood

    Science.gov (United States)

    Wood, Lindsey; Byram, Victoria; Gosling, A. Sophie; Stokes, Julie

    2012-01-01

    It has been argued that the grieving process after suicide bereavement has unique properties (e.g., J. R. Jordan, 2001). A qualitative study was conducted to explore one aspect of the grieving process--continuing bonds--after suicide bereavement in childhood. Data were collected through semi-structured interviews with 10 suicide-bereaved children…

  1. Interface Fracture in Adhesively Bonded Shell Structures

    DEFF Research Database (Denmark)

    Jensen, Henrik Myhre

    2008-01-01

    Two methods for the prediction of crack propagation through the interface of adhesively bonded shells are discussed. One is based on a fracture mechanics approach; the other is based on a cohesive zone approach. Attention is focussed on predicting the shape of the crack front and the critical...

  2. Oxytocin promotes social bonding in dogs.

    Science.gov (United States)

    Romero, Teresa; Nagasawa, Miho; Mogi, Kazutaka; Hasegawa, Toshikazu; Kikusui, Takefumi

    2014-06-24

    Recent evidence suggests that enduring social bonds have fitness benefits. However, very little is known about the neural circuitry and neurochemistry underlying the formation and maintenance of stable social bonds outside reproductive contexts. Oxytocin (OT), a neuropeptide synthetized by the hypothalamus in mammals, regulates many complex forms of social behavior and cognition in both human and nonhuman animals. Animal research, however, has concentrated on monogamous mammals, and it remains unknown whether OT also modulates social bonds in nonreproductive contexts. In this study we provide behavioral evidence that exogenous OT promotes positive social behaviors in the domestic dog toward not only conspecifics but also human partners. Specifically, when sprayed with OT, dogs showed higher social orientation and affiliation toward their owners and higher affiliation and approach behaviors toward dog partners than when sprayed with placebo. Additionally, the exchange of socio-positive behaviors with dog partners triggered the release of endogenous OT, highlighting the involvement of OT in the development of social relationships in the domestic dog. These data provide new insight into the mechanisms that facilitate the maintenance of close social bonds beyond immediate reproductive interest or genetic ties and complement a growing body of evidence that identifies OT as one of the neurochemical foundations of sociality in mammalian species.

  3. Hydrogen bonding in cytosinium dihydrogen phosphite

    OpenAIRE

    Nourredine Benali-Cherif; Amel Messai; Erwann Jeanneau; Dominique Luneau

    2009-01-01

    In the title compound, C4H8N3O4P+·H2PO3−, the cytosine molecule is monoprotonated and the phosphoric acid is in the monoionized state. Strong hydrogen bonds, dominated by N—H...O interactions, are responsible for cohesion between the organic and inorganic layers and maintain the stability of this structure.

  4. Hydrogen bonding in cytosinium dihydrogen phosphite

    Directory of Open Access Journals (Sweden)

    Nourredine Benali-Cherif

    2009-05-01

    Full Text Available In the title compound, C4H8N3O4P+·H2PO3−, the cytosine molecule is monoprotonated and the phosphoric acid is in the monoionized state. Strong hydrogen bonds, dominated by N—H...O interactions, are responsible for cohesion between the organic and inorganic layers and maintain the stability of this structure.

  5. Characterization of Hydrogen Bonds by IR Spectroscopy

    Directory of Open Access Journals (Sweden)

    Vojta, D.

    2012-05-01

    Full Text Available In the identification and quantification of hydrogen bond, as one of the most abundant non-covalent interactions in phenomena like self-assembly and molecular recognition, IR spectrosopy has been employed as the most sensitive method. The performance of the high dilution method enables determination of the stability constant of hydrogen-bonded complex as one of the most important thermodynamic quantities used in their characterization. However, the alleged experimental simplicity of the mentioned method is loaded with errors originating not only from researcher intervention but also independent from it. The second source of error is particularly emphasized and elaborated in this paper, which is designed as the recipe for the successful characterization of hydrogen bonds. Besides the enumeration of all steps in the determination of hydrogen-bonded stability constants, the reader can be acquainted with the most important ex perimental conditions that should be fulfilled in order to minimize the naturally occurring errors in this type of investigation. In the spectral analysis, the application of both uni- and multivariate approach has been discussed. Some computer packages, considering the latter, are mentioned, described, and recommended. KUI -10/2012Received August 1, 2011Accepted October 24, 2011

  6. Passing the Bond Issue (with Related Video)

    Science.gov (United States)

    Erickson, Paul W.

    2011-01-01

    When a bond referendum comes around for a school district, it often is the culmination of years of planning, strategizing and communicating to the public. Especially in these economic times, passing a building referendum is challenging. Complete transparency among the superintendent, school board and community is essential to communicate the…

  7. Approximate systems with confluent bonding mappings

    OpenAIRE

    Lončar, Ivan

    2001-01-01

    If X = {Xn, pnm, N} is a usual inverse system with confluent (monotone) bonding mappings, then the projections are confluent (monotone). This is not true for approximate inverse system. The main purpose of this paper is to show that the property of Kelley (smoothness) of the space Xn is a sufficient condition for the confluence (monotonicity) of the projections.

  8. 77 FR 72999 - Small Brewers Bond Reduction

    Science.gov (United States)

    2012-12-07

    ... 1986 (IRC), pertains to the taxation of distilled spirits, wines, and beer (see title 26 of the United... qualification of breweries, bonds and taxation, removals without payment of tax, and records and reporting..., including the increased number of small (``craft'') brewers. In an advance notice of proposed rulemaking...

  9. The Cost of Immediacy for Corporate Bonds

    DEFF Research Database (Denmark)

    Dick-Nielsen, Jens; Marco, Rossi

    Liquidity provision in the corporate bond market has become significantly more expensive after the 2008 credit crisis. Using index exclusions as a natural experiment during which uninformed index trackers request immediacy, we find that the price of immediacy has doubled for short-term investment...

  10. Hydrogen Bonding to Alkanes: Computational Evidence

    DEFF Research Database (Denmark)

    Hammerum, Steen; Olesen, Solveig Gaarn

    2009-01-01

    The structural, vibrational, and energetic properties of adducts of alkanes and strong cationic proton donors were studied with composite ab initio calculations. Hydrogen bonding in [D-H+ H-alkyl] adducts contributes to a significant degree to the interactions between the two components, which is...

  11. Improper, Blue-Shifting Hydrogen Bond

    Czech Academy of Sciences Publication Activity Database

    Hobza, Pavel; Havlas, Zdeněk

    2002-01-01

    Roč. 108, - (2002), s. 325-334 ISSN 1432-881X R&D Projects: GA MŠk LN00A032 Institutional research plan: CEZ:AV0Z4055905; CEZ:AV0Z4040901 Keywords : improper, blue-shifting hydrogen bond * properties * nature Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.421, year: 2002

  12. Electronic bond tuning with heterocyclic carbenes

    KAUST Repository

    Falivene, Laura; Caporaso, Lucia; Cavallo, Luigi; Jacobsen, Heiko

    2013-01-01

    have a propensity to increase the bonding of the labile ligand and of the substrate in Ru-promoted olefin metathesis, whereas negligible impact is expected on the stability of the ruthenacycle intermediate. In the case of Pd cross-coupling reactions

  13. Therapeutic bond judgments: Congruence and incongruence.

    Science.gov (United States)

    Atzil-Slonim, Dana; Bar-Kalifa, Eran; Rafaeli, Eshkol; Lutz, Wolfgang; Rubel, Julian; Schiefele, Ann-Kathrin; Peri, Tuvia

    2015-08-01

    The present study had 2 aims: (a) to implement West and Kenny's (2011) Truth-and-Bias model to simultaneously assess the temporal congruence and directional discrepancy between clients' and therapists' ratings of the bond facet of the therapeutic alliance, as they cofluctuate from session to session; and (b) to examine whether symptom severity and a personality disorder (PD) diagnosis moderate congruence and/or discrepancy. Participants included 213 clients treated by 49 therapists. At pretreatment, clients were assessed for a PD diagnosis and completed symptom measures. Symptom severity was also assessed at the beginning of each session, using client self-reports. Both clients and therapists rated the therapeutic bond at the end of each session. Therapists and clients exhibited substantial temporal congruence in their session-by-session bond ratings, but therapists' ratings tended to be lower than their clients' across sessions. Additionally, therapeutic dyads whose session-by-session ratings were more congruent also tended to have a larger directional discrepancy (clients' ratings being higher). Pretreatment symptom severity and PD diagnosis did not moderate either temporal congruence or discrepancy at the dyad level; however, during sessions when clients were more symptomatic, therapist and client ratings were both farther apart and tracked each other less closely. Our findings are consistent with a "better safe than sorry" pattern, which suggests that therapists are motivated to take a vigilant approach that may lead both to underestimation and to attunement to fluctuations in the therapeutic bond. (c) 2015 APA, all rights reserved).

  14. Operational test of bonded magnetocaloric plates

    DEFF Research Database (Denmark)

    Bahl, Christian; Navickaité, Kristina; Neves Bez, Henrique

    2017-01-01

    Bonded plates made by hot pressing La0.85Ce0.15Fe11.25Mn0.25Si1.5Hy particles and resin have been tested as active magnetic regenerators in a small scale magnetocaloric device. Firstly the plates were carefully characterised magnetically and thermally. The plates were prepared with 5 wt% resin...

  15. Wax-bonding 3D microfluidic chips

    KAUST Repository

    Gong, Xiuqing; Yi, Xin; Xiao, Kang; Li, Shunbo; Kodzius, Rimantas; Qin, Jianhua; Wen, Weijia

    2013-01-01

    We report a simple, low-cost and detachable microfluidic chip incorporating easily accessible paper, glass slides or other polymer films as the chip materials along with adhesive wax as the recycling bonding material. We use a laser to cut through the paper or film to form patterns and then sandwich the paper and film between glass sheets or polymer membranes . The hot-melt adhesive wax can realize bridge bonding between various materials, for example, paper, polymethylmethacrylate (PMMA) film, glass sheets, or metal plate. The bonding process is reversible and the wax is reusable through a melting and cooling process. With this process, a three-dimensional (3D) microfluidic chip is achievable by vacuating and venting the chip in a hot-water bath. To study the biocompatibility and applicability of the wax-based microfluidic chip, we tested the PCR compatibility with the chip materials first. Then we applied the wax-paper based microfluidic chip to HeLa cell electroporation (EP ). Subsequently, a prototype of a 5-layer 3D chip was fabricated by multilayer wax bonding. To check the sealing ability and the durability of the chip, green fluorescence protein (GFP) recombinant Escherichia coli (E. coli) bacteria were cultured, with which the chemotaxis of E. coli was studied in order to determine the influence of antibiotic ciprofloxacin concentration on the E. coli migration.

  16. Wax-bonding 3D microfluidic chips

    KAUST Repository

    Gong, Xiuqing

    2013-10-10

    We report a simple, low-cost and detachable microfluidic chip incorporating easily accessible paper, glass slides or other polymer films as the chip materials along with adhesive wax as the recycling bonding material. We use a laser to cut through the paper or film to form patterns and then sandwich the paper and film between glass sheets or polymer membranes . The hot-melt adhesive wax can realize bridge bonding between various materials, for example, paper, polymethylmethacrylate (PMMA) film, glass sheets, or metal plate. The bonding process is reversible and the wax is reusable through a melting and cooling process. With this process, a three-dimensional (3D) microfluidic chip is achievable by vacuating and venting the chip in a hot-water bath. To study the biocompatibility and applicability of the wax-based microfluidic chip, we tested the PCR compatibility with the chip materials first. Then we applied the wax-paper based microfluidic chip to HeLa cell electroporation (EP ). Subsequently, a prototype of a 5-layer 3D chip was fabricated by multilayer wax bonding. To check the sealing ability and the durability of the chip, green fluorescence protein (GFP) recombinant Escherichia coli (E. coli) bacteria were cultured, with which the chemotaxis of E. coli was studied in order to determine the influence of antibiotic ciprofloxacin concentration on the E. coli migration.

  17. Silicon waveguides produced by wafer bonding

    DEFF Research Database (Denmark)

    Poulsen, Mette; Jensen, Flemming; Bunk, Oliver

    2005-01-01

    X-ray waveguides are successfully produced employing standard silicon technology of UV photolithography and wafer bonding. Contrary to theoretical expectations for similar systems even 100 mu m broad guides of less than 80 nm height do not collapse and can be used as one dimensional waveguides...

  18. School Facilities and Tax Credit Bonds

    Science.gov (United States)

    Edelstein, Frederick S.

    2009-01-01

    The tax credit portion of the American Recovery and Reinvestment Act of 2009 (also known as the economic stimulus package or ARRA) has three different entities that can be used for various school construction including new, modernization, renovation and acquisition of sites for school projects. The bond rule notice and allocations have been issued…

  19. Bond Feasibility Study. Project Identification Committee Report.

    Science.gov (United States)

    Wichita Public Schools, KS.

    A committee, appointed by the Board of Education, was requested to make a comprehensive study of the school building needs of Unified School District No. 259. In an attempt to determine the feasibility of a general bond election to upgrade the public schools, the specific charge to the committee was to evaluate the needs for physical plant…

  20. The challenge of bonding treated wood

    Science.gov (United States)

    Charles R. Frihart

    2004-01-01

    Wood products are quite durable if exposure to moisture is minimized; however, most uses of wood involve considerable exposure to moisture. To preserve the wood, chemicals are used to minimize moisture pickup, to prevent insect attack, and/or to resist microbial growth. The chemicals used as preservatives can interfere with adhesive bonds to wood. Given the many...

  1. Competition of hydrogen bonds and halogen bonds in complexes of hypohalous acids with nitrogenated bases.

    Science.gov (United States)

    Alkorta, Ibon; Blanco, Fernando; Solimannejad, Mohammad; Elguero, Jose

    2008-10-30

    A theoretical study of the complexes formed by hypohalous acids (HOX, X = F, Cl, Br, I, and At) with three nitrogenated bases (NH 3, N 2, and NCH) has been carried out by means of ab initio methods, up to MP2/aug-cc-pVTZ computational method. In general, two minima complexes are found, one with an OH...N hydrogen bond and the other one with a X...N halogen bond. While the first one is more stable for the smallest halogen derivatives, the two complexes present similar stabilities for the iodine case and the halogen-bonded structure is the most stable one for the hypoastatous acid complexes.

  2. Using Diffusion Bonding in Making Piezoelectric Actuators

    Science.gov (United States)

    Sager, Frank E.

    2003-01-01

    A technique for the fabrication of piezoelectric actuators that generate acceptably large forces and deflections at relatively low applied voltages involves the stacking and diffusion bonding of multiple thin piezoelectric layers coated with film electrodes. The present technique stands in contrast to an older technique in which the layers are bonded chemically, by use of urethane or epoxy agents. The older chemical-bonding technique entails several disadvantages, including the following: It is difficult to apply the bonding agents to the piezoelectric layers. It is difficult to position the layers accurately and without making mistakes. There is a problem of disposal of hazardous urethane and epoxy wastes. The urethane and epoxy agents are nonpiezoelectric materials. As such, they contribute to the thickness of a piezoelectric laminate without contributing to its performance; conversely, for a given total thickness, the performance of the laminate is below that of a unitary piezoelectric plate of the same thickness. The figure depicts some aspects of the fabrication of a laminated piezoelectric actuator by the present diffusion- bonding technique. First, stock sheets of the piezoelectric material are inspected and tested. Next, the hole pattern shown in the figure is punched into the sheets. Alternatively, if the piezoelectric material is not a polymer, then the holes are punched in thermoplastic films. Then both faces of each punched piezoelectric sheet or thermoplastic film are coated with a silver-ink electrode material by use of a silkscreen printer. The electrode and hole patterns are designed for minimal complexity and minimal waste of material. After a final electrical test, all the coated piezoelectric layers (or piezoelectric layers and coated thermoplastic films) are stacked in an alignment jig, which, in turn, is placed in a curved press for the diffusion-bonding process. In this process, the stack is pressed and heated at a specified curing temperature

  3. Effect of mode of polymerization of bonding agent on shear bond strength of autocured resin composite luting cements.

    Science.gov (United States)

    Dong, Cecilia C S; McComb, Dorothy; Anderson, James D; Tam, Laura E

    2003-04-01

    There have been anecdotal reports of low bond strength with autocured resin composite materials, particularly when light-cured bonding agents that combine primer and adhesive in a 1-bottle preparation are used. The objective of this study was to determine if the mode of polymerization of the bonding agent influences the strength of the attachment of autocured resin composite luting cements to dentin. The shear bond strength of 2 resin luting cements, Calibra and RelyX ARC, polymerized by autocuring, in combination with 4 different bonding agents, Scotchbond Multipurpose Plus, Prime & Bond NT, IntegraBond and Single Bond, polymerized to bovine dentin by light-curing, autocuring or dual-curing, was determined. The pH of each bonding agent and its components was measured. Two-way analysis of variance was used to test the effect of cement and adhesive on shear bond strength. For each bonding agent, the adhesive variable combined the factors product brand and mode of polymerization. With significant interaction among the above variables, the least square means of the 16 combinations of resin cement and adhesive were compared. There was no consistent relationship between shear bond strength and mode of polymerization of the bonding agent. Significant differences in bond strength were specific to the proprietary brand of bonding agent. The pH of the bonding agent depends on the manufacturer's formulation, and low pH may contribute to low bond strength. The low in vitro bond strength occurring with some combinations of bonding agent and resin cement could be clinically significant.

  4. Microtensile bond strength of enamel after bleaching

    Directory of Open Access Journals (Sweden)

    Andréa Dias Neves Lago

    2013-01-01

    Full Text Available Objective: To evaluate the bond strength of a composite resin to the bovine enamel bleached with 35% hydrogen peroxide. It was used an etching-and-rinse adhesive system employed immediately, 7 and 14 days after the bleaching. Materials and Methods: Twenty bovine teeth were randomly distributed into 4 groups (n = 5, 3 experimental and 1 control. G1: Unbleached + restoration 14 days after storage in artificial saliva (control; G2: Bleached + restoration immediately after bleaching; G3: Bleached + restoration 7 days after bleaching; G4: Bleached + restoration 14 days after bleaching. Their buccal enamel surfaces were flattened, and a 25 mm² (5 × 5 mm area from each one of these regions was outlined so as to standardize the experimental region. Universal hybrid composite resin Filtek™Z350 was inserted into four layers of 1 mm each and photo-activated. The bond strength was quantitatively evaluated by a microtensile test (1.0 mm/min 24 h after the restorative procedures. The failure mode was assessed through scanning electron microscopy (SEM. Results: There was a significant reduction in the bond strength of the restored teeth immediately after the bleaching (G2. There were no significant differences in enamel bond strength between groups G1, G3, and G4. There was a predominance of adhesive and mixed (cohesive + adhesive failure in all groups. Conclusion: The 7-day-period after the end of the bleaching with 35% hydrogen peroxide was enough to achieve the appropriate values of bond strength to the enamel.

  5. Bond Ratings dan Antesedennya: Studi Empiris di Bursa Efek Indonesia

    Directory of Open Access Journals (Sweden)

    Wendy Wendy

    2017-01-01

    Full Text Available This paper provides the empirical evidence of corporate growth, maturity, and operating cash flows on the bond ratings. It was conducted on 34 bonds issued by the 16 non-financial companies on the Indonesia Stock Exchange (IDX which also issued bonds, registered in the Indonesia Bond Market Directory, and rated by PEFINDO during 2012 - 2014. The hypotheses were tested using the logistic regression analysis. The result shows that corporate growth has significant effect on the bond ratings, while maturity and operating cash flow have no significant effect. Another finding shows that the firm size can also affect the bond ratings.

  6. Zinc and resin bonded NdFeB magnets

    International Nuclear Information System (INIS)

    Leonowicz, M.; Kaszuwara, W.

    2002-01-01

    Zinc and resin bonded NdFeB magnets were processed. Basic magnetic parameters as well as compressive strength were evaluated versus annealing temperature and volume fraction of the bonding agent. For the zinc bonded magnets phase composition was investigated. The additional NdZn 5 phase was found in the Zn bonded magnets after annealing. Comparison of the Zn and resin bonded magnets reveals higher remanence for the former and higher coercivity for the latter. For the Zn and resin bonded magnets, 15 wt.% Zn / 370 o C and 7-10 wt.% resin were chosen as the optimal processing parameters. (author)

  7. BCB Bonding Technology of Back-Side Illuminated COMS Device

    Science.gov (United States)

    Wu, Y.; Jiang, G. Q.; Jia, S. X.; Shi, Y. M.

    2018-03-01

    Back-side illuminated CMOS(BSI) sensor is a key device in spaceborne hyperspectral imaging technology. Compared with traditional devices, the path of incident light is simplified and the spectral response is planarized by BSI sensors, which meets the requirements of quantitative hyperspectral imaging applications. Wafer bonding is the basic technology and key process of the fabrication of BSI sensors. 6 inch bonding of CMOS wafer and glass wafer was fabricated based on the low bonding temperature and high stability of BCB. The influence of different thickness of BCB on bonding strength was studied. Wafer bonding with high strength, high stability and no bubbles was fabricated by changing bonding conditions.

  8. The enhancement of the deteriorated South African bond options market

    Directory of Open Access Journals (Sweden)

    Coert Frederik Erasmus

    2015-06-01

    Full Text Available nvestments, especially those in the bond market, carry a level of risk. Risks in the bond market can be mitigated by transacting in option contracts. In the developing South African economy, trading activity of over-the-counter (OTC bond options decreased significantly. Possible deteriorating factors and interventions to enhance OTC bond options were investigated in this research. Experts in the OTC bond option market were surveyed and the quantitative data collected was analysed with descriptive statistical methods. Results indicated that three factors were positively identified as deteriorating factors in the OTC bond option market and that five different interventions were possible to possible enhance this market.

  9. Origin of the X-Hal (Hal = Cl, Br) bond-length change in the halogen-bonded complexes.

    Science.gov (United States)

    Wang, Weizhou; Hobza, Pavel

    2008-05-01

    The origin of the X-Hal bond-length change in the halogen bond of the X-Hal...Y type has been investigated at the MP2(full)/6-311++G(d,p) level of theory using a natural bond orbital analysis, atoms in molecules procedure, and electrostatic potential fitting methods. Our results have clearly shown that various theories explaining the nature of the hydrogen bond cannot be applied to explain the origin of the X-Hal bond-length change in the halogen bond. We provide a new explanation for this change. The elongation of the X-Hal bond length is caused by the electron-density transfer to the X-Hal sigma* antibonding orbital. For the blue-shifting halogen bond, the electron-density transfer to the X-Hal sigma* antibonding orbital is only of minor importance; it is the electrostatic attractive interaction that causes the X-Hal bond contraction.

  10. Proposal of guideline for bonding to prevention of hydrogen embrittlement at Ta/Zr bond interface. Hydrogen embrittlement in SUS304ULC/Ta/Zr explosive bonded joint

    International Nuclear Information System (INIS)

    Saida, Kazuyoshi; Fujimoto, Tetsuya; Nishimoto, Kazutoshi

    2010-01-01

    The occurrence condition of hydrogen embrittlement cracking at Ta/Zr bond interface was investigated with respect to the hydrogen content and applied stress in order to propose a guideline for the explosive bonding procedure to prevention of hydrogen embrittlement. Hydrogen charging test was conducted for SUS304ULC/Ta/Zr explosive bonded joints applied the different flexural strains. A hydrogen embrittlement crack occurred in the Zr substrate at Ta/Zr bond interface after hydrogen charging, and it was initiated at shorter charging times when the augmented strain was increased. The occurrence condition of hydrogen embrittlement cracking at Ta/Zr bond interface was shifted to lower stress and hydrogen content with an increase in the amount of explosive during bonding. It was suggested that hydrogen embrittlement in Ta/Zr explosive bonded joint could be inhibited by reducing the initial hydrogen content in Ta substrate less than approx. 5 ppm. (author)

  11. 77 FR 553 - Surety Companies Acceptable on Federal Bonds: Termination; Western Bonding Company

    Science.gov (United States)

    2012-01-05

    .... Department of the Treasury, Financial Management Service, Financial Accounting and Services Division, Surety..., 2011. Laura Carrico, Director, Financial Accounting and Services Division, Financial Management Service...: Termination; Western Bonding Company AGENCY: Financial Management Service, Fiscal Service, Department of the...

  12. A Comparison of Shear Bond Strength of Two Different Techniques with that of Initially Bonded Brackets

    Directory of Open Access Journals (Sweden)

    Abdolhamid Zafarmand

    2014-01-01

    Conclusion: However, there was no significant difference in the shear strength responses of three groups. The results of the study showed that both techniques of rebonding of failed brackets can provide effective bonding strengths similar to the primary strength.

  13. Polyurethane Binder Systems for Polymer Bonded Explosives

    Science.gov (United States)

    2006-12-01

    Propulsion (2005), Santiago , Chile . 8. Huang, C.-C., Hwu, W.-H., Cheng, C.-S., Shyy, I.-N., and Yang, K.-K., Study on Thermal Decomposition of Composite...water or amines to form ureas (Figure 2). R NCO R N C O H+ H2O O H R NH2 - CO2 R NCO R N C O NR’ H H ureaamine Figure 2. Reaction of an isocyanate...Monoisocyanates are present as impurities in low concentration in most diisocyanates. Table 1. Common diisocyanates Isocyanate Structure B.p. (ºC

  14. Shear Bond Strength of DentStat(trademark) for Bracket Bonding to Gold, Ceramic, and Enamel

    Science.gov (United States)

    2012-12-21

    they make a good choice for orthodontic bracket retention. According to a Cochrane review by Mandall (Mandall et al, 2002) all of their review...was developed as a temporary material for use in military field environments, can be used to effectively bond orthodontic brackets to type III gold... orthodontic composite resin adhesive, Transbond XTTM (3M Unitek Monrovia, California), as they are used to bond orthodontic brackets to gold

  15. Shear bond strength of orthodontic brackets bonded with different self-etching adhesives.

    Science.gov (United States)

    Scougall Vilchis, Rogelio José; Yamamoto, Seigo; Kitai, Noriyuki; Yamamoto, Kohji

    2009-09-01

    The purpose of this study was to compare the shear bond strength (SBS) of orthodontic brackets bonded with 4 self-etching adhesives. A total of 175 extracted premolars were randomly divided into 5 groups (n = 35). Group I was the control, in which the enamel was etched with 37% phosphoric acid, and stainless steel brackets were bonded with Transbond XT (3M Unitek, Monrovia, Calif). In the remaining 4 groups, the enamel was conditioned with the following self-etching primers and adhesives: group II, Transbond Plus and Transbond XT (3M Unitek); group III, Clearfil Mega Bond FA and Kurasper F (Kuraray Medical, Tokyo, Japan); group IV, Primers A and B, and BeautyOrtho Bond (Shofu, Kyoto, Japan); and group V, AdheSE and Heliosit Orthodontic (Ivoclar Vivadent AG, Liechtenstein). The teeth were stored in distilled water at 37 degrees C for 24 hours and debonded with a universal testing machine. The adhesive remnant index (ARI) including enamel fracture score was also evaluated. Additionally, the conditioned enamel surfaces were observed under a scanning electron microscope. The SBS values of groups I (19.0 +/- 6.7 MPa) and II (16.6 +/- 7.3 MPa) were significantly higher than those of groups III (11.0 +/- 3.9 MPa), IV (10.1 +/- 3.7 MPa), and V (11.8 +/- 3.5 MPa). Fluoride-releasing adhesives (Kurasper F and BeautyOrtho Bond) showed clinically acceptable SBS values. Significant differences were found in the ARI and enamel fracture scores between groups I and II. The 4 self-etching adhesives yielded SBS values higher than the bond strength (5.9 to 7.8 MPa) suggested for routine clinical treatment, indicating that orthodontic brackets can be successfully bonded with any of these self-etching adhesives.

  16. Effect of sodium ascorbate on the bond strength of silorane and methacrylate composites after vital bleaching

    Directory of Open Access Journals (Sweden)

    Eda Guler

    2013-07-01

    Full Text Available We investigated the effect of sodium ascorbate (SA on the microtensile bond strengths (MTBSs of different composites to bovine enamel after vital bleaching with hydrogen peroxide (HP or carbamide peroxide (CP. Thirty bovine incisors were randomly divided into five groups and treated with no bleaching application (control, 35% HP alone, 35% HP + 10% SA for 10 minutes (HP + SA, 16% CP alone, or 16% CP + 10% SA for 10 minutes (CP + SA. Specimens were restored with Silorane adhesive and Filtek Silorane composite (designated as S / group or with Clearfil SE bond and Filtek Supreme XT (designated as F / group. Composite build-up was created on the enamel. Sectioned specimens (n = 10 per group; 1 mm2; cross-sectional area were created and stressed in a universal testing machine at 1 mm/min crosshead speed. The application of 10% SA immediately after bleaching with 16% CP or 35% HP increased the enamel MTBS, regardless of the adhesive / composite resin used. The resulting MTBS values were similar to those of the control groups. Use of 16% CP and 35% HP alone decreased the enamel MTBS, regardless of the adhesive / composite resin used, with F / CP + SA = F / HP + SA = F / CP = S / CP + SA = S / HP + SA = S / C > S / CP = S / HP = F / CP = F / HP (p < 0.05. We concluded that the application of SA for 10 minutes immediately after vital bleaching increases the enamel BS for dimethacrylate- and silorane-based composites

  17. Body of Knowledge (BOK) for Copper Wire Bonds

    Science.gov (United States)

    Rutkowski, E.; Sampson, M. J.

    2015-01-01

    Copper wire bonds have replaced gold wire bonds in the majority of commercial semiconductor devices for the latest technology nodes. Although economics has been the driving mechanism to lower semiconductor packaging costs for a savings of about 20% by replacing gold wire bonds with copper, copper also has materials property advantages over gold. When compared to gold, copper has approximately: 25% lower electrical resistivity, 30% higher thermal conductivity, 75% higher tensile strength and 45% higher modulus of elasticity. Copper wire bonds on aluminum bond pads are also more mechanically robust over time and elevated temperature due to the slower intermetallic formation rate - approximately 1/100th that of the gold to aluminum intermetallic formation rate. However, there are significant tradeoffs with copper wire bonding - copper has twice the hardness of gold which results in a narrower bonding manufacturing process window and requires that the semiconductor companies design more mechanically rigid bonding pads to prevent cratering to both the bond pad and underlying chip structure. Furthermore, copper is significantly more prone to corrosion issues. The semiconductor packaging industry has responded to this corrosion concern by creating a palladium coated copper bonding wire, which is more corrosion resistant than pure copper bonding wire. Also, the selection of the device molding compound is critical because use of environmentally friendly green compounds can result in internal CTE (Coefficient of Thermal Expansion) mismatches with the copper wire bonds that can eventually lead to device failures during thermal cycling. Despite the difficult problems associated with the changeover to copper bonding wire, there are billions of copper wire bonded devices delivered annually to customers. It is noteworthy that Texas Instruments announced in October of 2014 that they are shipping microcircuits containing copper wire bonds for safety critical automotive applications

  18. Tensile and fatigue properties of weld-bonded and adhesive-bonded magnesium alloy joints

    International Nuclear Information System (INIS)

    Xu, W.; Liu, L.; Zhou, Y.; Mori, H.; Chen, D.L.

    2013-01-01

    The microstructures, tensile and fatigue properties of weld-bonded (WB) AZ31B-H24 Mg/Mg joints with different sizes of bonding area were evaluated and compared with the adhesive-bonded (AB) Mg/Mg joints. Typical equiaxed dendritic structures containing divorced eutectic Mg 17 Al 12 particles formed in the fusion zone of both WB-1 (with a bonding area of 35 mm×35 mm) and WB-0.5 (with a bonding area of 17.5 mm×35 mm) joints. Less solidification shrinkage cracking was observed in the WB-0.5 joints than WB-1 joints. While the WB-0.5 joints exhibited a slightly lower maximum tensile shear stress than the AB-0.5 joints (with a bonding area of 17.5 mm×35 mm), the energy absorption was equivalent. Although the AB-0.5 joints exhibited a higher fatigue resistance at higher cyclic stress levels, both the AB-0.5 and WB-0.5 joints showed an equivalent fatigue resistance at lower cyclic stress levels. A higher fatigue limit was observed in the WB-0.5 joints than in the WB-1 joints owing to the presence of fewer shrinkage pores. Cohesive failure mode along the adhesive layer in conjunction with partial nugget pull-out from the weld was observed at the higher cyclic loads, and fatigue failure occurred in the base metal at the lower cyclic loads

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

    Directory of Open Access Journals (Sweden)

    Andreas Hellak

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Mahdi S

    2008-06-01

    Full Text Available Amalgam′s non-adhesive characteristics necessitate cavity preparations incorporating retentive features, which often require the removal of non-carious tooth structure. Use of adhesives beneath amalgam restorations, would be helpful to overcome this disadvantage. This study was undertaken to compare the mean shear bond strength of amalgam bonded to primary and permanent dentin, to evaluate the efficacy of amalgam adhesives in pediatric dentistry.27 primary and 28 permanent posterior teeth with intact buccal or lingual surfaces were grounded to expose dentin and wet-polished with 400-grit silicone carbide paper. Scotchbond Multi Purpose Plus adhesive system was applied to the dentin surfaces and light cured. Amalgam was condensed onto the treated dentin through a plastic mold.shear bond strength testing was done using an Instron Universal testing machine, at a crosshead speed of 0.5 mm/min.The data were analyzed by independent samples t-test The difference among the two groups was not statistically significant (p>0.05 Bonded amalgam showed the same level of bond strength to primary and permanent dentin; so, application of amalgam bonding agents in pediatric dentistry can be recommended.

  1. [Delayed testing for the diagnosis of fungi in the urines. Evaluation of the BD Vacutainer C&S tubes for the storage of urine samples at room temperature].

    Science.gov (United States)

    Baixench, M T; Al-Sheikh, M; Paugam, A

    2005-01-01

    The study included 37 urine samples which have been artificially infected with low levels (10(3) CFU/mL) of various fungi strains. We compared the effects of sample storage, up to 48 hours, at room temperature, in a urine evacuated tube containing specific additives with storage at + 4 degrees C, for the same length of time, in a urine evacuated tube without any additives. There have been no differences of results (speed of growth and colony size) between the 2 modes of storage. However, the experience has shown that samples needed a careful mixing before seeding to avoid underdetection of the strains. Based on the study results, the BD Vacutainer C&S tubes are suitable for delayed testing for the diagnosis of urine fungal infection.

  2. The study of disorder and nanocrystallinity in C-S-H, supplementary cementitious materials and geopolymers using pair distribution function analysis

    International Nuclear Information System (INIS)

    Meral, Cagla; Benmore, C.J.; Monteiro, Paulo J.M.

    2011-01-01

    Significant progress was achieved with the application of Rietveld method to characterize the crystalline phases in portland cement paste. However, to obtain detailed information on the amorphous or poorly crystalline phases, it is necessary to analyze the total scattering data. The pair distribution function (PDF) method has been successfully used in the study of liquids and amorphous solids. The method takes the Sine Fourier transform of the measured structure factor over a wide momentum transfer range, providing a direct measure of the probability of finding an atom surrounding a central atom at a radial distance away. The obtained experimental characteristic distances can be also used to validate the predictions by the theoretical models, such as, molecular dynamics, ab initio simulations and density functional theory. The paper summarizes recent results of PDF analysis on silica fume, rice husk ash, fly ash, ASR gel, C-S-H and geopolymers.

  3. STUDY OF THE EFFECT OF ALUMINUM CONTENT AND C / S RATIO ON THE PHYSICO-MECHANICAL AND THERMAL PROPERTIES OF A LIGHTWEIGHT CONCRETE MADE FROM SAND DUNE

    Directory of Open Access Journals (Sweden)

    Z. Damene

    2015-07-01

    Full Text Available This research is a contribution to the development of local materials especially in the development of a cellular concrete with dunes sand. This is an experimental study whose objective is to see the influence of the C/S (dosage of cement compared to sand and the dosage of aluminum on the physico- mechanical and thermal performance of lightweight concrete cellular type. The results showed that the cement compared to the sand has a remarkable effect on the reaction and that on expansion the mechanical behavior as well as the dosage of aluminum in the composition of cellular concrete has a certain threshold Aluminium beyond which provides no relief benefits. Based on these results, the cellular concrete made from sand dune can be classified as light structural concrete with insulation suitable for very hot and arid environment of our region power.

  4. Bonding pathways of high-pressure chemical transformations

    International Nuclear Information System (INIS)

    Hu Anguang; Zhang Fan

    2013-01-01

    A three-stage bonding pathway towards high-pressure chemical transformations from molecular precursors or intermediate states has been identified by first-principles simulations. With the evolution of principal stress tensor components in the response of chemical bonding to compressive loading, the three stages can be defined as the van der Waals bonding destruction, a bond breaking and forming reaction, and equilibrium of new bonds. The three-stage bonding pathway leads to the establishment of a fundamental principle of chemical bonding under compression. It reveals that during high-pressure chemical transformation, electrons moving away from functional groups follow anti-addition, collision-free paths to form new bonds in counteracting the local stress confinement. In applying this principle, a large number of molecular precursors were identified for high-pressure chemical transformations, resulting in new materials. (fast track communication)

  5. Hydrogen-bonding patterns involving a cyclic phosphate

    Indian Academy of Sciences (India)

    Administrator

    Phosphates, which always have electronegative oxygen atoms, bear no exception in their involvement in ... water makes the study of structural patterns due to H-bonding much too complicated. We ... H-bonding features found in all the above.

  6. 27 CFR 17.103 - Bonds obtained from surety companies.

    Science.gov (United States)

    2010-04-01

    ... its liability, in terms upon the face of the bond, to a definite, specified amount. This amount shall... obtained from: Surety Bond Branch, Financial Management Service, Department of the Treasury, Washington, DC...

  7. Intramolecularly Hydrogen-Bonded Polypyrroles as Electro-Optical Sensors

    National Research Council Canada - National Science Library

    Nicholson, Jesse

    2001-01-01

    We have developed a new class of polypyrroles bearing both hydrogen-bond acceptor and hydrogen-donor groups such that the intramolecular hydrogen bonding holds the system planar enhancing conjugation...

  8. Contractile fibers and catch bond clusters : a biological force sensor?

    NARCIS (Netherlands)

    Novikova, E.A.; Storm, C.

    2013-01-01

    Catch bonds are cellular receptor-ligand pairs whose lifetime, counterintuitively, increases with increasing load. Although their existence was initially pure theoretical speculation, recent years have seen several experimental demonstrations of catch-bond behavior in biologically relevant and

  9. Interest Rates and Coupon Bonds in Quantum Finance

    Science.gov (United States)

    Baaquie, Belal E.

    2009-09-01

    1. Synopsis; 2. Interest rates and coupon bonds; 3. Options and option theory; 4. Interest rate and coupon bond options; 5. Quantum field theory of bond forward interest rates; 6. Libor Market Model of interest rates; 7. Empirical analysis of forward interest rates; 8. Libor Market Model of interest rate options; 9. Numeraires for bond forward interest rates; 10. Empirical analysis of interest rate caps; 11. Coupon bond European and Asian options; 12. Empirical analysis of interest rate swaptions; 13. Correlation of coupon bond options; 14. Hedging interest rate options; 15. Interest rate Hamiltonian and option theory; 16. American options for coupon bonds and interest rates; 17. Hamiltonian derivation of coupon bond options; Appendixes; Glossaries; List of symbols; Reference; Index.

  10. Structure, bonding and energetics of N-heterocyclic carbene (NHC ...

    Indian Academy of Sciences (India)

    ... of Science Education and Research (NISER), Bhubaneswar, 751 005 India .... out with Gaussian software with the default conver- .... with Multiwfn software.67 The FBO bond order has ... free energy ( G) of bond dissociation are given in.

  11. Extreme population inversion in the fragments formed by UV photoinduced S-H bond fission in 2-thiophenethiol.

    Science.gov (United States)

    Ingle, Rebecca A; Karsili, Tolga N V; Dennis, Gregg J; Staniforth, Michael; Stavros, Vasilios G; Ashfold, Michael N R

    2016-04-28

    H atom loss following near ultraviolet photoexcitation of gas phase 2-thiophenethiol molecules has been studied experimentally, by photofragment translational spectroscopy (PTS) methods, and computationally, by ab initio electronic structure calculations. The long wavelength (277.5 ≥ λ(phot) ≥ 240 nm) PTS data are consistent with S-H bond fission after population of the first (1)πσ* state. The partner thiophenethiyl (R) radicals are formed predominantly in their first excited Ã(2)A' state, but assignment of a weak signal attributable to H + R(X˜(2)A'') products allows determination of the S-H bond strength, D0 = 27,800 ± 100 cm(-1) and the Ã-X˜ state splitting in the thiophenethiyl radical (ΔE = 3580 ± 100 cm(-1)). The deduced population inversion between the à and X˜ states of the radical reflects the non-planar ground state geometry (wherein the S-H bond is directed near orthogonal to the ring plane) which, post-photoexcitation, is unable to planarise sufficiently prior to bond fission. This dictates that the dissociating molecules follow the adiabatic fragmentation pathway to electronically excited radical products. π* ← π absorption dominates at shorter excitation wavelengths. Coupling to the same (1)πσ* potential energy surface (PES) remains the dominant dissociation route, but a minor yield of H atoms attributable to a rival fragmentation pathway is identified. These products are deduced to arise via unimolecular decay following internal conversion to the ground (S0) state PES via a conical intersection accessed by intra-ring C-S bond extension. The measured translational energy disposal shows a more striking change once λ(phot) ≤ 220 nm. Once again, however, the dominant decay pathway is deduced to be S-H bond fission following coupling to the (1)πσ* PES but, in this case, many of the evolving molecules are deduced to have sufficiently near-planar geometries to allow passage through the conical intersection at extended S-H bond

  12. Shear bond strength of two bonding systems on dentin surfaces prepared with Er:YAG laser

    International Nuclear Information System (INIS)

    Dall'Magro, Eduardo

    2001-01-01

    The purpose of this study was to examine the shear bond strength of two bonding dentin systems, one 'one step' (Single Bond - 3M) and one 'self-etching' (Prompt-L-ESPE), when applied on dentin surfaces prepared with Er:YAG laser (2,94μm) that underwent ar not, acid etched. Forty one human molars just extracted were selected and after the cut with diamond disc and included in acrylic resin, resulting in 81 specimens (hemi crowns). After, the specimens were divided in one group treated with sand paper and another two groups treated with Er:YAG laser with 200 mJ and 250 mJ of energy and 2 Hz of frequency. Next, the prepared surfaces received three treatments with following application: 1) acid + Single Bond + Z 250 resin, 2) prompt-L-Pop + Z 250 resin, and 3) acid without, Single Bond + Z 250 resin. The Z 250 resin was applied and photopolymerized in increments on a Teflon matrix that belonged to an apparatus called 'Assembly Apparatus' machine producing cylinders of 3,5 mm of diameter and 5 mm of height. After these specimens were submitted to thermo cycling during 1 minute the 55 deg C and during 1 minute with 5 deg C with a total of 500 cycles for specimen, and the measures of shear bond strength were abstained using EMIC model DL 2000 rehearsed machine, with speed of 0,5 mm/min, measuring the final rupture tension (Mpa). The results showed an statistic superiority of 5% of probability level in dentin flattened with sandpaper and with laser using 200 mJ of energy with aspect to the ones flattened with laser using 250 mJ of energy. It was observed that using 'Single Bond' bonding dentin system the marks were statistically superior at 5% of probability with reference to the use of the Prompt-L-Pop adhesive system. So, it was concluded that Er:YAG Laser with 200 mJ of energy produced similar dentin cavity prepare than sandpaper and Single Bond seemed the best bonding agent system between restorative material and dentin. (author)

  13. Reliability Criteria for Thick Bonding Wire.

    Science.gov (United States)

    Dagdelen, Turker; Abdel-Rahman, Eihab; Yavuz, Mustafa

    2018-04-17

    Bonding wire is one of the main interconnection techniques. Thick bonding wire is widely used in power modules and other high power applications. This study examined the case for extending the use of traditional thin wire reliability criteria, namely wire flexure and aspect ratio, to thick wires. Eleven aluminum (Al) and aluminum coated copper (CucorAl) wire samples with diameter 300 μm were tested experimentally. The wire response was measured using a novel non-contact method. High fidelity FEM models of the wire were developed and validated. We found that wire flexure is not correlated to its stress state or fatigue life. On the other hand, aspect ratio is a consistent criterion of thick wire fatigue life. Increasing the wire aspect ratio lowers its critical stress and increases its fatigue life. Moreover, we found that CucorAl wire has superior performance and longer fatigue life than Al wire.

  14. Reliability Criteria for Thick Bonding Wire

    Directory of Open Access Journals (Sweden)

    Turker Dagdelen

    2018-04-01

    Full Text Available Bonding wire is one of the main interconnection techniques. Thick bonding wire is widely used in power modules and other high power applications. This study examined the case for extending the use of traditional thin wire reliability criteria, namely wire flexure and aspect ratio, to thick wires. Eleven aluminum (Al and aluminum coated copper (CucorAl wire samples with diameter 300 μm were tested experimentally. The wire response was measured using a novel non-contact method. High fidelity FEM models of the wire were developed and validated. We found that wire flexure is not correlated to its stress state or fatigue life. On the other hand, aspect ratio is a consistent criterion of thick wire fatigue life. Increasing the wire aspect ratio lowers its critical stress and increases its fatigue life. Moreover, we found that CucorAl wire has superior performance and longer fatigue life than Al wire.

  15. A cerium(IV)-carbon multiple bond

    Energy Technology Data Exchange (ETDEWEB)

    Gregson, Matthew; Lu, Erli; McMaster, Jonathan; Lewis, William; Blake, Alexander J.; Liddle, Stephen T. [Nottingham Univ. (United Kingdom). School of Chemistry

    2013-12-02

    Straightforward access to a cerium(IV)-carbene complex was provided by one-electron oxidation of an anionic ''ate'' cerium(III)-carbene precursor, thereby avoiding decomposition reactions that plague oxidations of neutral cerium(III) compounds. The cerium(IV)-carbene complex is the first lanthanide(IV)-element multiple bond and involves a twofold bonding interaction of two electron pairs between cerium and carbon. [German] Auf direktem Wege zu einem Cer(IV)-Carbenkomplex gelangt man durch die Einelektronenoxidation einer anionischen Carben-Cerat(III)-Vorstufe. So werden Zersetzungsprozesse vermieden, die die Oxidation neutraler Cer(III)-Verbindungen erschweren. Der Cer(IV)-Carbenkomplex enthaelt die erste Lanthanoid(IV)-Element-Mehrfachbindung; dabei binden Cer und Kohlenstoff ueber zwei Elektronenpaare.

  16. Electronic bond tuning with heterocyclic carbenes

    KAUST Repository

    Falivene, Laura

    2013-01-01

    We discuss the impact of the nature of the heterocyclic carbene ring, when used as a complex forming ligand, on the relative stability of key intermediates in three typical Ru, Pd and Au promoted reactions. Results show that P-heterocyclic carbenes have a propensity to increase the bonding of the labile ligand and of the substrate in Ru-promoted olefin metathesis, whereas negligible impact is expected on the stability of the ruthenacycle intermediate. In the case of Pd cross-coupling reactions, dissociation of a P-heterocyclic carbene is easier than dissociation of the N-heterocyclic analogue. In the case of the Au-OH synthon, the Au-OH bond is weakened with the P-heterocyclic carbene ligands. A detailed energy decomposition analysis is performed to rationalize these results. © 2013 The Royal Society of Chemistry.

  17. Atomic bonding between metal and graphene

    KAUST Repository

    Wang, Hongtao

    2013-03-07

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

  18. Determine bond strength by ultrasonic measurement

    International Nuclear Information System (INIS)

    Brown, C.M.

    1978-01-01

    Application of ultrasonic methods for the evaluation and measurement of bond strength has been the object of numerous investigations in the last fifteen years. Some investigators have reported good success (in limited application) while others have experienced dismal failure. One problem common to all investigations was the difficulty in extracting and isolating the many components which comprise the ultrasonic signal reflected from a bonded interface. Part of this problem was due to manually extracting individual parameters from large volumes of raw data. However, with the vast technology now available in the field of signal analysis and computerized data processing, it is feasible to isolate and analyze individual parameters within the ultrasonic signal for great volumes of raw data

  19. Variance Risk Premia on Stocks and Bonds

    DEFF Research Database (Denmark)

    Mueller, Philippe; Sabtchevsky, Petar; Vedolin, Andrea

    We study equity (EVRP) and Treasury variance risk premia (TVRP) jointly and document a number of findings: First, relative to their volatility, TVRP are comparable in magnitude to EVRP. Second, while there is mild positive co-movement between EVRP and TVRP unconditionally, time series estimates...... equity returns for horizons up to 6-months, long maturity TVRP contain robust information for long run equity returns. Finally, exploiting the dynamics of real and nominal Treasuries we document that short maturity break-even rates are a power determinant of the joint dynamics of EVRP, TVRP and their co-movement...... of correlation display distinct spikes in both directions and have been notably volatile since the financial crisis. Third $(i)$ short maturity TVRP predict excess returns on short maturity bonds; $(ii)$ long maturity TVRP and EVRP predict excess returns on long maturity bonds; and $(iii)$ while EVRP predict...

  20. Article coated with flash bonded superhydrophobic particles

    Science.gov (United States)

    Simpson, John T [Clinton, TN; Blue, Craig A [Knoxville, TN; Kiggans, Jr., James O [Oak Ridge, TN

    2010-07-13

    A method of making article having a superhydrophobic surface includes: providing a solid body defining at least one surface; applying to the surface a plurality of diatomaceous earth particles and/or particles characterized by particle sizes ranging from at least 100 nm to about 10 .mu.m, the particles being further characterized by a plurality of nanopores, wherein at least some of the nanopores provide flow through porosity, the particles being further characterized by a plurality of spaced apart nanostructured features that include a contiguous, protrusive material; flash bonding the particles to the surface so that the particles are adherently bonded to the surface; and applying a hydrophobic coating layer to the surface and the particles so that the hydrophobic coating layer conforms to the nanostructured features.

  1. Reliability Criteria for Thick Bonding Wire

    Science.gov (United States)

    Yavuz, Mustafa

    2018-01-01

    Bonding wire is one of the main interconnection techniques. Thick bonding wire is widely used in power modules and other high power applications. This study examined the case for extending the use of traditional thin wire reliability criteria, namely wire flexure and aspect ratio, to thick wires. Eleven aluminum (Al) and aluminum coated copper (CucorAl) wire samples with diameter 300 μm were tested experimentally. The wire response was measured using a novel non-contact method. High fidelity FEM models of the wire were developed and validated. We found that wire flexure is not correlated to its stress state or fatigue life. On the other hand, aspect ratio is a consistent criterion of thick wire fatigue life. Increasing the wire aspect ratio lowers its critical stress and increases its fatigue life. Moreover, we found that CucorAl wire has superior performance and longer fatigue life than Al wire. PMID:29673194

  2. Bond portfolio's duration and investment term-structure management problem

    OpenAIRE

    Liu, Daobai

    2006-01-01

    In the considered bond market, there are N zero-coupon bonds transacted continuously, which will mature at equally spaced dates. A duration of bond portfolios under stochastic interest rate model is introduced, which provides a measurement for the interest rate risk. Then we consider an optimal bond investment term-structure management problem using this duration as a performance index, and with the short-term interest rate process satisfying some stochastic differential ...

  3. Bond strength and microleakage of current dentin adhesives.

    Science.gov (United States)

    Fortin, D; Swift, E J; Denehy, G E; Reinhardt, J W

    1994-07-01

    The purpose of this in vitro study was to evaluate shear bond strengths and microleakage of seven current-generation dentin adhesive systems. Standard box-type Class V cavity preparations were made at the cemento-enamel junction on the buccal surfaces of eighty extracted human molars. These preparations were restored using a microfill composite following application of either All-Bond 2 (Bisco), Clearfil Liner Bond (Kuraray), Gluma 2000 (Miles), Imperva Bond (Shofu), OptiBond (Kerr), Prisma Universal Bond 3 (Caulk), Scotchbond Multi-Purpose (3M), or Scotchbond Dual-Cure (3M) (control). Lingual dentin of these same teeth was exposed and polished to 600-grit. Adhesives were applied and composite was bonded to the dentin using a gelatin capsule technique. Specimens were thermocycled 500 times. Shear bond strengths were determined using a universal testing machine, and microleakage was evaluated using a standard silver nitrate staining technique. Clearfill Liner Bond and OptiBond, adhesive systems that include low-viscosity, low-modulus intermediate resins, had the highest shear bond strengths (13.3 +/- 2.3 MPa and 12.9 +/- 1.5 MPa, respectively). Along with Prisma Universal Bond 3, they also had the least microleakage at dentin margins of Class V restorations. No statistically significant correlation between shear bond strength and microleakage was observed in this study. Adhesive systems that include a low-viscosity intermediate resin produced the high bond strengths and low microleakage. Similarly, two materials with bond strengths in the intermediate range had significantly increased microleakage, and one material with a bond strength in the low end of the spectrum exhibited microleakage that was statistically greater. Thus, despite the lack of statistical correlation, there were observable trends.

  4. [The application of universal adhesives in dental bonding].

    Science.gov (United States)

    Guo, Jingmei; Lei, Wenlong; Yang, Hongye; Huang, Cui

    2016-03-01

    The bonding restoration has become an important clinical technique for the development of dental bonding technology. Because of its easy operation and the maximum preservation of tooth tissues, bonding repair is widely used in dental restoration. The recent multi-mode universal adhesives have brought new progress in dental bonding restoration. In this article the universal adhesives were reviewed according to its definition, development, improvement, application features and possible problems.

  5. Manufacturing and sustainability of bonding systems for grinding tools

    OpenAIRE

    Linke, B

    2016-01-01

    © 2016, German Academic Society for Production Engineering (WGP). Grinding and honing processes are quality-defining operations in the production of many modern products. Process performance and product quality are contingent on selecting the correct abrasive tool for a specific application. Thus, tools with different bonding systems are used, namely resin bonded tools, vitrified bonded tools, and metallic bonded tools. Tool manufacturers have great knowledge in the choice and intricate prod...

  6. FACTORS INFLUENCING YIELD SPREADS OF THE MALAYSIAN BONDS

    OpenAIRE

    Norliza Ahmad; Joriah Muhammad; Tajul Ariffin Masron

    2009-01-01

    Malaysian bond market is developing rapidly but not much is understood in terms of macroeconomic factors that could influence the yield spread of the Ringgit Malaysian denominated bonds. Based on a multifactor model, this paper examines the impact of four macroeconomic factors namely: Kuala Lumpur Composite Index (KLCI), Industry Production Index (IPI), Consumer Price Index (CPI) and interest rates (IR) on bond yield spread of the Malaysian Government Securities (MGS) and Corporate Bonds (CBs...

  7. India's Bond Market-Developments and Challenges Ahead

    OpenAIRE

    Schou-Zibell, Lotte; Wells, Stephen

    2008-01-01

    While India boasts a world-class equity market and increasingly important bank assets, its bond market has not kept up. The government bond market remains illiquid. The corporate bond market, in addition, remains restrictive to participants and largely arbitrage-driven. Securitization, which once had the jump on other Asian markets, has failed to take off. To meet the needs of its firms and investors, the bond market must therefore evolve. This will mean creating new market sectors such as ex...

  8. Funding the Search for Extraterrestrial Intelligence with a Lottery Bond

    OpenAIRE

    Haqq-Misra, Jacob

    2013-01-01

    I propose the establishment of a SETI Lottery Bond to provide a continued source of funding for the search for extraterrestrial intelligence (SETI). The SETI Lottery Bond is a fixed rate perpetual bond with a lottery at maturity, where maturity occurs only upon discovery and confirmation of extraterrestrial intelligent life. Investors in the SETI Lottery Bond purchase shares that yield a fixed rate of interest that continues indefinitely until SETI succeeds---at which point a random subset of...

  9. Evaluation of Callable Bonds: Finite Difference Methods, Stability and Accuracy.

    OpenAIRE

    Buttler, Hans-Jurg

    1995-01-01

    The purpose of this paper is to evaluate numerically the semi-American callable bond by means of finite difference methods. This study implies three results. First, the numerical error is greater for the callable bond price than for the straight bond price, and too large for real applications Secondly, the numerical accuracy of the callable bond price computed for the relevant range of interest rates depends entirely on the finite difference scheme which is chosen for the boundary points. Thi...

  10. Insertion reactions into Pd[bond]O and Pd[bond]N bonds: preparation of alkoxycarbonyl, carbonato, carbamato, thiocarbamate, and thioureide complexes of palladium(II).

    Science.gov (United States)

    Ruiz, José; Martínez, M Teresa; Florenciano, Félix; Rodríguez, Venancio; López, Gregorio; Pérez, José; Chaloner, Penny A; Hitchcock, Peter B

    2003-06-02

    Mononuclear palladium hydroxo complexes of the type [Pd(N[bond]N)(C(6)F(5))(OH)] [(N[bond]N = 2,2'-bipyridine (bipy), 4,4'-dimethyl-2,2'-bipyridine (Me(2)bipy), 1,10-phenanthroline (phen), or N,N,N',N'-tetramethylethylenediamine (tmeda)] have been prepared by reaction of [Pd(N[bond]N)(C(6)F(5))(acetone)]ClO(4) with KOH in methanol. These hydroxo complexes react, in methanol, with CO (1 atm, room temperature) to yield the corresponding methoxycarbonyl complexes [Pd(N[bond]N)(C(6)F(5))(CO(2)Me)]. Similar alkoxycarbonyl complexes [Pd(N[bond]N)(C(6)F(5))(CO(2)R)] (N[bond]N = bis(3,5-dimethylpyrazol-1-yl)methane); R = Me, Et, or (i)Pr) are obtained when [Pd(N[bond]N)(C(6)F(5))Cl] is treated with KOH in the corresponding alcohol ROH and CO is bubbled through the solution. The reactions of [Pd(N[bond]N)(C(6)F(5))(OH)] (N[bond]N = bipy or Me(2)bipy) with CO(2), in tetrahydrofuran, lead to the formation of the binuclear carbonate complexes [(N[bond]N)(C(6)F(5))Pd(mu-eta(2)-CO(3))Pd(C(6)F(5))(N[bond]N)]. Complexes [Pd(N[bond]N)(C(6)F(5))(OH)] react in alcohol with PhNCS to yield the corresponding N-phenyl-O-alkylthiocarbamate complexes [Pd(N[bond]N)(C(6)F(5))[SC(OR)NPh

  11. Environmental Durability of Adhesively Bonded Joints

    Science.gov (United States)

    1997-10-14

    REPORT DOCUMENTATION PAGE Form Approved OMB No. 07040188 Public reporting burden for tis collection of information isestimated to average 1 hour per...transmittance and reflectance spectroscopy was performed using Nicolet’s OMNIC software for the set-up, control, and analysis of spectroscopic scans... publications inciudc: JAhIN’. W S. iind Butjkus, L.M., "Considetring E~nvironmental Condjitions ill the Design ()’ Bonded Structures: A Fracture

  12. Bond graph modeling of nuclear reactor dynamics

    International Nuclear Information System (INIS)

    Tylee, J.L.

    1981-01-01

    A tenth-order linear model of a pressurized water reactor (PWR) is developed using bond graph techniques. The model describes the nuclear heat generation process and the transfer of this heat to the reactor coolant. Comparisons between the calculated model response and test data from a small-scale PWR show the model to be an adequate representation of the actual plant dynamics. Possible application of the model in an advanced plant diagnostic system is discussed

  13. Graphene composites containing chemically bonded metal oxides

    Indian Academy of Sciences (India)

    the oxide layers are chemically bonded to graphene (Zhang ... sists of three glass chambers, one to contain the metal halide. (TiCl4, SiCl4 ... In this step, the metal halide reacts with the oxygen function- ... 1·0 g of FeCl3 were vigorously stirred in 30 ml of ethylene ... Reaction with water vapour results in hydrolysis of the un-.

  14. An empirical analysis of Diaspora bonds

    OpenAIRE

    AKKOYUNLU, Şule; STERN, Max

    2018-01-01

    Abstract. This study is the first to investigate theoretically and empirically the determinants of Diaspora Bonds for eight developing countries (Bangladesh, Ethiopia, Ghana, India, Lebanon, Pakistan, the Philippines, and Sri-Lanka) and one developed country - Israel for the period 1951 and 2008. Empirical results are consistent with the predictions of the theoretical model. The most robust variables are the closeness indicator and the sovereign rating, both on the demand-side. The spread is ...

  15. Characterization of cyclic peptides containing disulfide bonds

    OpenAIRE

    Johnson, Mindy; Liu, Mingtao; Struble, Elaine; Hettiarachchi, Kanthi

    2015-01-01

    Unlike linear peptides, analysis of cyclic peptides containing disulfide bonds is not straightforward and demands indirect methods to achieve a rigorous proof of structure. Three peptides that belong to this category, p-Cl-Phe-DPDPE, DPDPE, and CTOP, were analyzed and the results are presented in this paper. The great potential of two dimensional NMR and ESI tandem mass spectrometry was harnessed during the course of peptide characterizations. A new RP-HPLC method for the analysis of trifluor...

  16. Intramolecular Energy Transfer, Charge Transfer & Hydrogen Bond

    Indian Academy of Sciences (India)

    Ultrafast Dynamics of Chemical Reactions in Condensed Phase: Intramolecular Energy Transfer, Charge Transfer & Hydrogen Bond · PowerPoint Presentation · Slide 3 · Slide 4 · Slide 5 · Slide 6 · Slide 7 · Slide 8 · Slide 9 · Slide 10 · Slide 11 · Slide 12 · Slide 13 · Slide 14 · Slide 15 · Slide 16 · Slide 17 · Slide 18 · Slide 19.

  17. Apparatus Tests Peeling Of Bonded Rubbery Material

    Science.gov (United States)

    Crook, Russell A.; Graham, Robert

    1996-01-01

    Instrumented hydraulic constrained blister-peel apparatus obtains data on degree of bonding between specimen of rubbery material and rigid plate. Growth of blister tracked by video camera, digital clock, pressure transducer, and piston-displacement sensor. Cylinder pressure controlled by hydraulic actuator system. Linear variable-differential transformer (LVDT) and float provide second, independent measure of change in blister volume used as more precise volume feedback in low-growth-rate test.

  18. Properties of glass-bonded zeolite monoliths

    International Nuclear Information System (INIS)

    Lewis, M.A.; Fischer, D.F.; Murphy, C.D.

    1994-01-01

    It has been shown that mineral waste forms can be used to immobilize waste salt generated during the pyrochemical processing of spent fuel from the Integral Fast Reactor (IFR). Solid, leach resistant monoliths were formed by hot-pressing mixtures of salt-occluded zeolite A powders and glass frit at 990 K and 28 MPa. Additional samples have now been fabricated and tested. Normalized release rates for all elements, including iodide and chloride, were less than 1 g/m 2 d in 28-day tests in deionized water and in brine at 363 K (90 degrees C). Preliminary results indicate that these rates fall with time with both leachants and that the zeolite phase in the glass-bonded zeolite does not function as an ion exchanger. Some material properties were measured. The Poisson ratio and Young's modulus were slightly smaller in glass-bonded zeolite than in borosilicate glass. Density depended on zeolite fraction. The glass-bonded zeolite represents a promising mineral waste form for IFR salt

  19. Hybrid FSWeld-bonded joint fatigue behaviour

    Science.gov (United States)

    Lertora, Enrico; Mandolfino, Chiara; Gambaro, Carla; Pizzorni, Marco

    2018-05-01

    Aluminium alloys, widely used in aeronautics, are increasingly involved in the automotive industry due to the good relationship between mechanical strength and specific weight. The lightening of the structures is the first objective, which allows the decreasing in the weight in motion. The use of aluminium alloys has also seen the introduction of the Friction Stir Welding (FSW) technique for the production of structural overlapping joints. FSW allows us to weld overlap joints free from defects, but with the presence of a structural notch further aggravated by the presence of a "hook" defect near the edge of the weld. Furthermore, FSW presents a weld penetration area connected to the tool geometry and penetration. The experimental activity will be focused on the combination of two different joining techniques, which can synergistically improve the final joint resistance. In particular, the welding and bonding process most commonly known as weld-bonding is defined as a hybrid process, as it combines two different junction processes. In this paper we analyse FSWelded AA6082 aluminium alloy overlapped joint with the aim of quantitatively evaluating the improvement provided by the presence of an epoxy adhesive between the plates. After optimising the weld-bonding process, the mechanical behaviour of welded joints will be analysed by static and dynamic tests. The presence of the adhesive should limit the negative effect of the structural notch inevitable in a FSW overlapped joint.

  20. Parental bonding and suicidality in adulthood.

    Science.gov (United States)

    Heider, Dirk; Bernert, Sebastian; Matschinger, Herbert; Haro, Josep M; Alonso, Jordi; Angermeyer, Matthias C

    2007-01-01

    The short-term effect of an adverse parental child rearing style on suicidality in adolescence has been extensively discussed. Nevertheless, little is known about the long-term effect of adverse parental child rearing on lifetime suicidality in adulthood. So the present study aims to examine the relation between parental bonding on the one hand and suicidality in adulthood on the other. We used data from 7740 respondents of the European Study of Epidemiology of Mental Disorders project, a cross-sectional household survey carried out in six European countries. The data were assessed with the World Mental Health Composite International Diagnostic Interview, a comprehensive, fully structured psychiatric diagnostic interview. Suicidality was categorized as follows: 'no ideation', 'ideation', 'attempt'. Parental bonding was assessed by means of a three-factor ('care', 'overprotection', 'authoritarianism') short form of the Parental Bonding Instrument. Using a multinomial-logistic regression model to investigate the association between these two constructs, we also adjusted for mood disorders, anxiety disorders, alcohol abuse/dependence and possible country effects. We found associations between low maternal and paternal care on the one hand and suicidality on the other. Country-specific differences proved negligible. Prevention programs can help better equip parents in their child-rearing role to create a more caring parenting environment. This can be a protective factor for suicidality in adulthood. Nevertheless, more efforts are necessary to better describe the paths that lead from child-rearing behaviour to suicidality in adulthood.

  1. Bonding and expressed emotion: two interlinked concepts?

    Science.gov (United States)

    Duclos, Jeanne; Maria, Anne-Solène; Dorard, Géraldine; Curt, Florence; Apfel, Alexandre; Vibert, Sarah; Rein, Zoé; Perdereau, Fabienne; Godart, Nathalie

    2013-01-01

    Bonding and expressed emotion (EE) are two concepts modeling family relationships. Two studies, with contradictory results, have explored whether these concepts and their corresponding instruments [the Parental Bonding Instrument (PBI) and the Camberwell Family Interview] do indeed measure the same aspects of family relationships. Our first objective was to compare the adolescents' perceptions of family relationships using the PBI, and the parental viewpoint using the Five-Minute Speech Sample (FMSS-EE). Secondly, we compared the PBI scores and EE levels of the parents. Sixty adolescent girls with anorexia nervosa completed the PBI. The FMSS and a modified version of the PBI were administered to parents separately. No significant link was identified between adolescent PBI scores and parental EE levels. However, a link between maternal 'modified' PBI scores and maternal EE was observed: when mothers registered a high Final EE, they were more likely to deny their daughter's psychological autonomy compared to mothers with lower EE. Our empirical results do not support the hypothesis of an overlap between the two concepts. Indeed bonding and EE measure the same object, i.e. the quality of family relationships, but time scales differ and so do the perspectives (patient vs. parental viewpoint). Copyright © 2012 S. Karger AG, Basel.

  2. On the efficiency of sovereign bond markets

    Science.gov (United States)

    Zunino, Luciano; Fernández Bariviera, Aurelio; Guercio, M. Belén; Martinez, Lisana B.; Rosso, Osvaldo A.

    2012-09-01

    The existence of memory in financial time series has been extensively studied for several stock markets around the world by means of different approaches. However, fixed income markets, i.e. those where corporate and sovereign bonds are traded, have been much less studied. We believe that, given the relevance of these markets, not only from the investors', but also from the issuers' point of view (government and firms), it is necessary to fill this gap in the literature. In this paper, we study the sovereign market efficiency of thirty bond indices of both developed and emerging countries, using an innovative statistical tool in the financial literature: the complexity-entropy causality plane. This representation space allows us to establish an efficiency ranking of different markets and distinguish different bond market dynamics. We conclude that the classification derived from the complexity-entropy causality plane is consistent with the qualifications assigned by major rating companies to the sovereign instruments. Additionally, we find a correlation between permutation entropy, economic development and market size that could be of interest for policy makers and investors.

  3. Valuing Euro rating-triggered step-up telecom bonds

    NARCIS (Netherlands)

    P. Houweling (Patrick); A.A. Mentink; A.C.F. Vorst (Ton)

    2003-01-01

    textabstractWe value rating-triggered step-up bonds with three methods: (i) the Jarrow, Lando and Turnbull (1997, JLT) framework, (ii) a similar framework using historical probabilities and (iii) as plain vanilla bonds. We find that the market seems to value single step-up bonds according to the JLT

  4. Valuing Euro Rating-Triggered Step-Up Telecom Bonds

    NARCIS (Netherlands)

    P. Houweling (Patrick); A.A. Mentink; A.C.F. Vorst (Ton)

    2003-01-01

    textabstractWe value rating-triggered step-up bonds with three methods: (i) the Jarrow, Lando and Turnbull (1997, JLT) framework, (ii) a similar framework using historical probabilities and (iii) as plain vanilla bonds. We find that the market seems to value single step-up bonds according to the JLT

  5. Crack propagation studies and bond coat properties in thermal

    Indian Academy of Sciences (India)

    High threshold load at the interface between the ceramic layer and the bond coat was required to propagate the crack further into the bond coat. Once the threshold load was surpassed the crack propagated into the brittle bond coat without an appreciable increase in the load. At temperatures of 800°C the crack propagated ...

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

    DEFF Research Database (Denmark)

    Svaneborg, Carsten

    2012-01-01

    and bond types. When breaking bonds, all angular and dihedral interactions involving broken bonds are removed. The framework allows chemical reactions to be modeled, and use it to simulate a simplistic, coarse-grained DNA model. The resulting DNA dynamics illustrates the power of the present framework....

  7. Effect of simulated pulpal pressure on composite bond strength to ...

    African Journals Online (AJOL)

    Statistical significance was determined by T-test (p < 0.05). There was a statistically significant difference in the mean microtensile bond strengths between the groups (p < 0.0005). Simulated pulpal pressure had a negative effect on microtensile bond strength of laser ablated dentin when Single Bond adhesive system was ...

  8. 30 CFR 800.30 - Replacement of bonds.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Replacement of bonds. 800.30 Section 800.30... REQUIREMENTS FOR SURFACE COAL MINING AND RECLAMATION OPERATIONS UNDER REGULATORY PROGRAMS § 800.30 Replacement... replacement performance bonds. Replacement of a performance bond pursuant to this section shall not constitute...

  9. Intermolecular hydrogen bonds: From temperature-driven proton ...

    Indian Academy of Sciences (India)

    Abstract. We have combined neutron scattering and a range of numerical simulations to study hydrogen bonds in condensed matter. Two examples from a recent thesis will be presented. The first concerns proton transfer with increasing temperature in short inter- molecular hydrogen bonds [1,2]. These bonds have unique ...

  10. 27 CFR 46.207 - Articles held in bond.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Articles held in bond. 46... Tubes Held for Sale on April 1, 2009 Inventories § 46.207 Articles held in bond. If the dealer is a manufacturer or an export warehouse proprietor and holds articles in TTB bond on April 1, 2009, the floor...

  11. 48 CFR 31.205-4 - Bonding costs.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Bonding costs. 31.205-4... REQUIREMENTS CONTRACT COST PRINCIPLES AND PROCEDURES Contracts With Commercial Organizations 31.205-4 Bonding costs. (a) Bonding costs arise when the Government requires assurance against financial loss to itself...

  12. 48 CFR 970.3102-05-4 - Bonding costs.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 5 2010-10-01 2010-10-01 false Bonding costs. 970.3102-05... SUPPLEMENTARY REGULATIONS DOE MANAGEMENT AND OPERATING CONTRACTS Contract Cost Principles and Procedures 970.3102-05-4 Bonding costs. (d) The allowability of bonding costs shall be determined pursuant to 970.5228...

  13. Characteristics of the wood adhesion bonding mechanism using hydroxymethyl resorcinol

    Science.gov (United States)

    Douglas J. Gardner; Charles E. Frazier; Alfred W. Christiansen

    2006-01-01

    A recent collaborative effort among the U.S. Forest Products Laboratory, Virginia Tech, and the University of Maine has explored the possible bonding mechanisms contributing to durable wood adhesive bonding using hydroxymethyl resorcinol (HMR) surface treatment. Current adhesive bonding mechanisms include: mechanical interlocking, electronic or electrostatic theory,...

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

    Science.gov (United States)

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

    2012-01-01

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

  15. Phase transitions in liquids with directed intermolecular bonding

    OpenAIRE

    Son, L.; Ryltcev, R.

    2005-01-01

    Liquids with quasi - chemical bonding between molecules are described in terms of vertex model. It is shown that this bonding results in liquid - liquid phase transition, which occurs between phases with different mean density of intermolecular bonds. The transition may be suggested to be a universal phenomena for those liquids.

  16. Corporate Bond Guarantees and The Value of Financial Flexibility

    NARCIS (Netherlands)

    Altieri, M.; Massa, M; Manconi, A

    2016-01-01

    We examine the effects of the decision of parent companies to guarantee bonds issued by their subsidiaries. The market value of the parent firm’s outstanding bonds drops five times more when it issues a guarantee for subsidiary debt than when it issues a new bond in its own name. This effect is

  17. Single-crystal micromachining using multiple fusion-bonded layers

    Science.gov (United States)

    Brown, Alan; O'Neill, Garry; Blackstone, Scott C.

    2000-08-01

    Multi-layer structures have been fabricated using Fusion bonding. The paper shows void free layers of between 2 and 100 microns that have been bonded to form multi-layer structures. Silicon layers have been bonded both with and without interfacial oxide layers.

  18. Covalent versus ionic bonding in alkalimetal fluoride oligomers

    NARCIS (Netherlands)

    Bickelhaupt, F.M.; Sola, M.; Fonseca Guerra, C.

    2007-01-01

    The most polar bond in chemistry is that between a fluorine and an alkalimetal atom. Inspired by our recent finding that other polar bonds (C - M and H - M) have important covalent contributions (i.e., stabilization due to bond overlap), we herein address the question if covalency is also essential

  19. 27 CFR 72.24 - Corporate surety bonds.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Corporate surety bonds. 72... Seizures and Forfeitures § 72.24 Corporate surety bonds. (a) Corporate surety bonds may be given only with... obtained from the Audit Staff, Bureau of Government Financial Operations, Department of the Treasury...

  20. Do Convertible Bond Issuers Cater to Investor Demand?

    NARCIS (Netherlands)

    de Jong, Abe; Duca, Eric; Dutordoir, Marie

    2013-01-01

    We examine the impact of fluctuations in investor demand for convertible securities on convertible bond issue volumes, pricing, and design. We find evidence of a positive impact of investor demand proxies on convertible bond issue volumes. We also document significantly lower convertible bond

  1. 27 CFR 28.286 - Receipt in customs bonded warehouse.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Receipt in customs bonded... in Customs Bonded Warehouse § 28.286 Receipt in customs bonded warehouse. On receipt of the distilled spirits or wine and the related TTB Form 5100.11 or 5110.30 as the case may be, the customs officer in...

  2. 27 CFR 24.107 - Designation as a bonded winery.

    Science.gov (United States)

    2010-04-01

    ... winery. 24.107 Section 24.107 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE... Designation as a bonded winery. Bonded wine premises which will be used for the production of wine or for production processes involving the use of wine will be designated a bonded winery unless the proprietor...

  3. 77 FR 10621 - Changes to the In-Bond Process

    Science.gov (United States)

    2012-02-22

    ... submit in-bond applications electronically using a CBP-approved electronic data interchange (EDI) system... electronically submit the in-bond application to CBP via a CBP-approved EDI system. \\6\\ Due to the unique... as the CBP-approved EDI system for submitting the in-bond application and other information that is...

  4. Bonded stacked-ring insulator for the Antares electron gun

    International Nuclear Information System (INIS)

    Stine, R.D.; Allen, G.R.; Eaton, E.; Weinstein, B.

    1982-01-01

    A large diameter insulator utilizing epoxy bonding which has sufficient mechanical strength to support the 3000 kg cathode/grid assembly was developed. Bonding the insulator simplifies the handling and reduces the number of 0-ring seals to a minimum. We have described the material selection, bonding techniques and electrical design approach

  5. 19 CFR 113.55 - Cancellation of export bonds.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Cancellation of export bonds. 113.55 Section 113... export bonds. (a) Manner of cancellation. A bond to assure exportation as defined in § 101.1 of this... shall be signed by a revenue officer of the foreign country to which the merchandise is exported, unless...

  6. 27 CFR 24.141 - Bonded wine warehouse.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Bonded wine warehouse. 24..., DEPARTMENT OF THE TREASURY LIQUORS WINE Establishment and Operations Permanent Discontinuance of Operations § 24.141 Bonded wine warehouse. Where all operations at a bonded wine warehouse are to be permanently...

  7. Bond strength of composite resin to enamel: assessment of two ethanol wet-bonding techniques.

    Directory of Open Access Journals (Sweden)

    Maryam Khoroushi

    2014-04-01

    Full Text Available Ethanol wet-bonding (EWB technique has been stated to decrease degradation of resin-dentin bond. This study evaluated the effect of two EWB techniques on composite resin-to-enamel bond strength.Silicon carbide papers were used to produce flat enamel surfaces on the buccal faces of forty-five molars. OptiBond FL (OFL adhesive was applied on enamel surfaces in three groups of 15 namely: Enamel surface and OFL (control;Protocol 1 of the EWB technique: absolute ethanol was applied to water-saturated acid-etched enamel surfaces for 1 minute before the application of ethanol-solvated hydrophobic adhesive resin of OFL 3 times;Protocol 2: progressive ethanol replacement; water was gradually removed from the enamel matrix using ascending ethanol concentrations before OFL application. Composite build-ups were made and the specimens were stored for 24 hours at 37°C and 100% relative humidity. Shear bond strength test was performed using a universal testing machine at 1 mm/min crosshead speed. Fracture patterns were evaluated microscopically. Data were analyzed with one-way ANOVA and Fisher's exact test (α=0.05.There were no significant differences in bond strength between the groups (P=0.73. However, regarding failure patterns, the highest cohesive enamel fractures were recorded in groups 2 and 3.In this study, although both methods of EWB did not influence immediate bond strength of composite resin to enamel, the majority of failure patterns occurred cohesively in enamel.

  8. Cement bond evaluation method in horizontal wells using segmented bond tool

    Science.gov (United States)

    Song, Ruolong; He, Li

    2018-06-01

    Most of the existing cement evaluation technologies suffer from tool eccentralization due to gravity in highly deviated wells and horizontal wells. This paper proposes a correction method to lessen the effects of tool eccentralization on evaluation results of cement bond using segmented bond tool, which has an omnidirectional sonic transmitter and eight segmented receivers evenly arranged around the tool 2 ft from the transmitter. Using 3-D finite difference parallel numerical simulation method, we investigate the logging responses of centred and eccentred segmented bond tool in a variety of bond conditions. From the numerical results, we find that the tool eccentricity and channel azimuth can be estimated from measured sector amplitude. The average of the sector amplitude when the tool is eccentred can be corrected to the one when the tool is centred. Then the corrected amplitude will be used to calculate the channel size. The proposed method is applied to both synthetic and field data. For synthetic data, it turns out that this method can estimate the tool eccentricity with small error and the bond map is improved after correction. For field data, the tool eccentricity has a good agreement with the measured well deviation angle. Though this method still suffers from the low accuracy of calculating channel azimuth, the credibility of corrected bond map is improved especially in horizontal wells. It gives us a choice to evaluate the bond condition for horizontal wells using existing logging tool. The numerical results in this paper can provide aids for understanding measurements of segmented tool in both vertical and horizontal wells.

  9. UNA METODOLOGÍA PARA VALORAR UN CALLABLE BOND A METHODOLOGY TO VALUE A CALLABLE BOND

    Directory of Open Access Journals (Sweden)

    Carlos Alexander Grajales

    2008-12-01

    Full Text Available En este artículo, la metodología empleada para valorar un bono que tiene una opción call incluida (callable bond o bono redimible viene dada por la implementación numérica del modelo de tasa corta de Hull y White, la cual se logra con un árbol trinomial de tasas. Así mismo, se presenta una aplicación para el caso de la compañía Interconexión Eléctrica S. A. -ISA-, que ha emitido dos instrumentos callable bonds. Para el desarrollo de tal aplicación se construyen algunos algoritmos computacionales, los cuales pueden valorar los dos bonos con opción call que tiene dicha compañía y además permiten la estructuración de un bono con opción call incluida de tipo genérico.In this paper the methodology employed for assessing a bond that includes a call option (callable bond is given by the numeric implementation of Hull and White short rate model, which it is accomplished through an interest rates trinomial tree. It also presents an application for the case of the company Interconexión Eléctrica S. A. -ISA-, which has issued two callable bonds instruments. For the development of such application computer algorithms are implemented to value the two bonds of the company, and they also allow the structuring of a bond with a generic type call option included.

  10. 31 CFR 353.3 - Converting definitive savings bonds to book-entry bonds in New Treasury Direct.

    Science.gov (United States)

    2010-07-01

    ... New Treasury Direct, an online system for holding Treasury securities. The Web address for New... bonds should follow online instructions for conversion. Regulations governing converted bonds are found at 31 CFR part 363. [70 FR 14941, Mar. 23, 2005] ...

  11. Facial expressions and pair bonds in hylobatids.

    Science.gov (United States)

    Florkiewicz, Brittany; Skollar, Gabriella; Reichard, Ulrich H

    2018-06-06

    Facial expressions are an important component of primate communication that functions to transmit social information and modulate intentions and motivations. Chimpanzees and macaques, for example, produce a variety of facial expressions when communicating with conspecifics. Hylobatids also produce various facial expressions; however, the origin and function of these facial expressions are still largely unclear. It has been suggested that larger facial expression repertoires may have evolved in the context of social complexity, but this link has yet to be tested at a broader empirical basis. The social complexity hypothesis offers a possible explanation for the evolution of complex communicative signals such as facial expressions, because as the complexity of an individual's social environment increases so does the need for communicative signals. We used an intraspecies, pair-focused study design to test the link between facial expressions and sociality within hylobatids, specifically the strength of pair-bonds. The current study compared 206 hr of video and 103 hr of focal animal data for ten hylobatid pairs from three genera (Nomascus, Hoolock, and Hylobates) living at the Gibbon Conservation Center. Using video footage, we explored 5,969 facial expressions along three dimensions: repertoire use, repertoire breadth, and facial expression synchrony [FES]. We then used focal animal data to compare dimensions of facial expressiveness to pair bond strength and behavioral synchrony. Hylobatids in our study overlapped in only half of their facial expressions (50%) with the only other detailed, quantitative study of hylobatid facial expressions, while 27 facial expressions were uniquely observed in our study animals. Taken together, hylobatids have a large facial expression repertoire of at least 80 unique facial expressions. Contrary to our prediction, facial repertoire composition was not significantly correlated with pair bond strength, rates of territorial synchrony

  12. Evaluation of the anti-cariogenic potential and bond strength to enamel of different fluoridated materials used for bracket bonding

    OpenAIRE

    SILVA, Sérgio Ricardo da; SILVA, Luciana Alves Herdy da; BASTING, Roberta Tarkany; LIMA-ARSATI, Ynara Bosco de Oliveira

    2017-01-01

    Abstract Objective To evaluate the in vitro and in situ anti-cariogenic potential and bond strength to enamel of materials containing fluoride (F), used for bracket bonding: Transbond XT (GT, negative control), Transbond Plus Color Change (GTF), Transbond-Self-Etching Primer (GSAF) and Vitremer (GV, positive control). Material and method In the in vitro study, the specimens were premolars with bonded brackets (n=12/group). After pH cycling, the F release, bond strength, fracture mode and pr...

  13. Prediction of fracture toughness and durability of adhesively bonded composite joints with undesirable bonding conditions

    Science.gov (United States)

    Musaramthota, Vishal

    Advanced composite materials have enabled the conventional aircraft structures to reduce weight, improve fuel efficiency and offer superior mechanical properties. In the past, materials such as aluminum, steel or titanium have been used to manufacture aircraft structures for support of heavy loads. Within the last decade or so, demand for advanced composite materials have been emerging that offer significant advantages over the traditional metallic materials. Of particular interest in the recent years, there has been an upsurge in scientific significance in the usage of adhesively bonded composite joints (ABCJ's). ABCJ's negate the introduction of stress risers that are associated with riveting or other classical techniques. In today's aircraft transportation market, there is a push to increase structural efficiency by promoting adhesive bonding to primary joining of aircraft structures. This research is focused on the issues associated with the durability and related failures in bonded composite joints that continue to be a critical hindrance to the universal acceptance of ABCJ's. Of particular interest are the short term strength, contamination and long term durability of ABCJ's. One of the factors that influence bond performance is contamination and in this study the influence of contamination on composite-adhesive bond quality was investigated through the development of a repeatable and scalable surface contamination procedure. Results showed an increase in the contaminant coverage area decreases the overall bond strength significantly. A direct correlation between the contaminant coverage area and the fracture toughness of the bonded joint was established. Another factor that influences bond performance during an aircraft's service life is its long term strength upon exposure to harsh environmental conditions or when subjected to severe mechanical loading. A test procedure was successfully developed in order to evaluate durability of ABCJ's comprising severe

  14. Microtensile bond strength of silorane-based composite specific adhesive system using different bonding strategies

    Directory of Open Access Journals (Sweden)

    Laura AlveBastos

    2015-02-01

    Full Text Available Objectives The aim of this study was to evaluate the effect of pre-etching on the bond strength of silorane-based composite specific adhesive system to dentin. Materials and Methods Thirty human molars were randomly divided into 5 groups according to the different bonding strategies. For teeth restored with silorane-based composite (Filtek Silorane, 3M ESPE, the specific self-etching adhesive system (Adhesive System P90, 3M ESPE was used with and without pre-etching (Pre-etching/Silorane and Silorane groups. Teeth restored with methacrylate based-composite (Filtek Z250, 3M ESPE were hybridized with the two-step self-etching system (Clearfil SE Bond, Kuraray, with and without pre-etching (Pre-etching/Methacrylate and Methacrylate groups, or three-step adhesive system (Adper Scotchbond Multi-Purpose, 3M ESPE (Three-step/Methacrylate group (n = 6. The restored teeth were sectioned into stick-shaped test specimens (1.0 × 1.0 mm, and coupled to a universal test machine (0.5 mm/min to perform microtensile testing. Results Pre-etching/Methacrylate group presented the highest bond strength values, with significant difference from Silorane and Three-step/Methacrylate groups (p < 0.05. However, it was not significantly different from Preetching/Silorane and Methacrylate groups. Conclusions Pre-etching increased bond strength of silorane-based composite specific adhesive system to dentin.

  15. Real space in situ bond energies: toward a consistent energetic definition of bond strength.

    Science.gov (United States)

    Menéndez-Crespo, Daniel; Costales, Aurora; Francisco, Evelio; Martin Pendas, Angel

    2018-04-14

    A rigorous definition of intrinsic bond strength based on the partitioning of a molecule into real space fragments is presented. Using the domains provided by the quantum theory of atoms in molecules (QTAIM) together with the interacting quantum atoms (IQA) energetic decomposition, we show how an in situ bond strength, matching all the requirements of an intrinsic bond energy, can be defined between each pair of fragments. Total atomization or fragmentation energies are shown to be equal to the sum of these in situ bond energies (ISBEs) if the energies of the fragments are measured with respect to their in-the-molecule state. These energies usually lie above the ground state of the isolated fragments by quantities identified with the standard fragment relaxation or deformation energies, which are also provided by the protocol. Deformation energies bridge dissociation energies with ISBEs, and can be dissected using well-known tools of real space theories of chemical bonding. Similarly, ISBEs can be partitioned into ionic and covalent contributions, and this feature adds to the chemical appeal of the procedure. All the energetic quantities examined are observable and amenable, in principle, to experimental determination. Several systems, exemplifying the role of each energetic term herein presented are used to show the power of the approach. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. A systematic structural study of halogen bonding versus hydrogen bonding within competitive supramolecular systems

    Directory of Open Access Journals (Sweden)

    Christer B. Aakeröy

    2015-09-01

    Full Text Available As halogen bonds gain prevalence in supramolecular synthesis and materials chemistry, it has become necessary to examine more closely how such interactions compete with or complement hydrogen bonds whenever both are present within the same system. As hydrogen and halogen bonds have several fundamental features in common, it is often difficult to predict which will be the primary interaction in a supramolecular system, especially as they have comparable strength and geometric requirements. To address this challenge, a series of molecules containing both hydrogen- and halogen-bond donors were co-crystallized with various monotopic, ditopic symmetric and ditopic asymmetric acceptor molecules. The outcome of each reaction was examined using IR spectroscopy and, whenever possible, single-crystal X-ray diffraction. 24 crystal structures were obtained and subsequently analyzed, and the synthon preferences of the competing hydrogen- and halogen-bond donors were rationalized against a background of calculated molecular electrostatic potential values. It has been shown that readily accessible electrostatic potentials can offer useful practical guidelines for predicting the most likely primary synthons in these co-crystals as long as the potential differences are weighted appropriately.

  17. Raman spectroscopy of supported chromium oxide catalysts : determination of chromium-oxygen bond distances and bond orders

    NARCIS (Netherlands)

    Weckhuysen, B.M.; Wachs, I.E.

    1996-01-01

    An empirical correlation is described for relating Raman stretching frequencies of chromium—oxygen (Cr—O) bonds to their bond lengths in chromium oxide reference compounds. An exponential fit of crystallographically determined Cr—O bond lengths to Cr—O Raman symmetric stretching frequencies

  18. 31 CFR 315.3 - Converting definitive savings bonds to book-entry bonds in New Treasury Direct.

    Science.gov (United States)

    2010-07-01

    ... book-entry bonds through New Treasury Direct, an online system for holding Treasury securities. The Web... definitive savings bonds should follow online instructions for conversion. Regulations governing converted bonds are found at 31 CFR part 363. [70 FR 14941, Mar. 23, 2005] ...

  19. Hydrogen bond donor–acceptor–donor organocatalysis for conjugate addition of benzylidene barbiturates via complementary DAD– ADA hydrogen bonding

    NARCIS (Netherlands)

    Leung, King-Chi; Cui, Jian-Fang; Hui, Tsz-Wai; Zhou, Zhong-Yuan; Wong, Man-Kin

    2014-01-01

    A new class of hydrogen bond donor-acceptor-donor (HB-DAD) organocatalysts has been developed for conjugate addition of benzylidene barbiturates. HB-DAD organocatalyst 1a (featuring para-chloro-pyrimidine as the hydrogen bond acceptor (HBA), N-H as the hydrogen bond donor (HBD) and a trifluoroacetyl

  20. Efficacy of microtensile versus microshear bond testing for evaluation of bond strength of dental adhesive systems to enamel

    NARCIS (Netherlands)

    El Zohairy, A.A.; Saber, M.H.; Abdalla, A.I.; Feilzer, A.J.

    2010-01-01

    Objective The aim of the study was to evaluate the efficacy of the microtensile bond test (μTBS) and the microshear bond test (μSBS) in ranking four dental adhesives according to bond strength to enamel and identify the modes of failure involved. Materials and methods Forty-four caries-free human