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Sample records for dityrosine bonds regulates

  1. UV-light exposure of insulin: pharmaceutical implications upon covalent insulin dityrosine dimerization and disulphide bond photolysis.

    Directory of Open Access Journals (Sweden)

    Manuel Correia

    Full Text Available In this work we report the effects of continuous UV-light (276 nm, ~2.20 W.m(-2 excitation of human insulin on its absorption and fluorescence properties, structure and functionality. Continuous UV-excitation of the peptide hormone in solution leads to the progressive formation of tyrosine photo-product dityrosine, formed upon tyrosine radical cross-linkage. Absorbance, fluorescence emission and excitation data confirm dityrosine formation, leading to covalent insulin dimerization. Furthermore, UV-excitation of insulin induces disulphide bridge breakage. Near- and far-UV-CD spectroscopy shows that UV-excitation of insulin induces secondary and tertiary structure losses. In native insulin, the A and B chains are held together by two disulphide bridges. Disruption of either of these bonds is likely to affect insulin's structure. The UV-light induced structural changes impair its antibody binding capability and in vitro hormonal function. After 1.5 and 3.5 h of 276 nm excitation there is a 33.7% and 62.1% decrease in concentration of insulin recognized by guinea pig anti-insulin antibodies, respectively. Glucose uptake by human skeletal muscle cells decreases 61.7% when the cells are incubated with pre UV-illuminated insulin during 1.5 h. The observations presented in this work highlight the importance of protecting insulin and other drugs from UV-light exposure, which is of outmost relevance to the pharmaceutical industry. Several drug formulations containing insulin in hexameric, dimeric and monomeric forms can be exposed to natural and artificial UV-light during their production, packaging, storage or administration phases. We can estimate that direct long-term exposure of insulin to sunlight and common light sources for indoors lighting and UV-sterilization in industries can be sufficient to induce irreversible changes to human insulin structure. Routine fluorescence and absorption measurements in laboratory experiments may also induce changes

  2. UV-light exposure of insulin: pharmaceutical implications upon covalent insulin dityrosine dimerization and disulphide bond photolysis.

    Science.gov (United States)

    Correia, Manuel; Neves-Petersen, Maria Teresa; Jeppesen, Per Bendix; Gregersen, Søren; Petersen, Steffen B

    2012-01-01

    In this work we report the effects of continuous UV-light (276 nm, ~2.20 W.m(-2)) excitation of human insulin on its absorption and fluorescence properties, structure and functionality. Continuous UV-excitation of the peptide hormone in solution leads to the progressive formation of tyrosine photo-product dityrosine, formed upon tyrosine radical cross-linkage. Absorbance, fluorescence emission and excitation data confirm dityrosine formation, leading to covalent insulin dimerization. Furthermore, UV-excitation of insulin induces disulphide bridge breakage. Near- and far-UV-CD spectroscopy shows that UV-excitation of insulin induces secondary and tertiary structure losses. In native insulin, the A and B chains are held together by two disulphide bridges. Disruption of either of these bonds is likely to affect insulin's structure. The UV-light induced structural changes impair its antibody binding capability and in vitro hormonal function. After 1.5 and 3.5 h of 276 nm excitation there is a 33.7% and 62.1% decrease in concentration of insulin recognized by guinea pig anti-insulin antibodies, respectively. Glucose uptake by human skeletal muscle cells decreases 61.7% when the cells are incubated with pre UV-illuminated insulin during 1.5 h. The observations presented in this work highlight the importance of protecting insulin and other drugs from UV-light exposure, which is of outmost relevance to the pharmaceutical industry. Several drug formulations containing insulin in hexameric, dimeric and monomeric forms can be exposed to natural and artificial UV-light during their production, packaging, storage or administration phases. We can estimate that direct long-term exposure of insulin to sunlight and common light sources for indoors lighting and UV-sterilization in industries can be sufficient to induce irreversible changes to human insulin structure. Routine fluorescence and absorption measurements in laboratory experiments may also induce changes in protein

  3. 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.

  4. Health Effects of Dietary Oxidized Tyrosine and Dityrosine Administration in Mice with Nutrimetabolomic Strategies.

    Science.gov (United States)

    Yang, Yuhui; Zhang, Hui; Yan, Biao; Zhang, Tianyu; Gao, Ying; Shi, Yonghui; Le, Guowei

    2017-08-16

    This study aims to investigate the health effects of long-term dietary oxidized tyrosine (O-Tyr) and its main product (dityrosine) administration on mice metabolism. Mice received daily intragastric administration of either O-Tyr (320 μg/kg body weight), dityrosine (Dityr, 320 μg/kg body weight), or saline for consecutive 6 weeks. Urine and plasma samples were analyzed by NMR-based metabolomics strategies. Body weight, clinical chemistry, oxidative damage indexes, and histopathological data were obtained as complementary information. O-Tyr and Dityr exposure changed many systemic metabolic processes, including reduced choline bioavailability, led to fat accumulation in liver, induced hepatic injury, and renal dysfunction, resulted in changes in gut microbiota functions, elevated risk factor for cardiovascular disease, altered amino acid metabolism, induced oxidative stress responses, and inhibited energy metabolism. These findings implied that it is absolutely essential to reduce the generation of oxidation protein products in food system through improving modern food processing methods.

  5. The involvement of dityrosine crosslinking in α-synuclein assembly and deposition in Lewy Bodies in Parkinson’s disease

    Science.gov (United States)

    Al-Hilaly, Youssra K.; Biasetti, Luca; Blakeman, Ben J. F.; Pollack, Saskia J.; Zibaee, Shahin; Abdul-Sada, Alaa; Thorpe, Julian R.; Xue, Wei-Feng; Serpell, Louise C.

    2016-01-01

    Parkinson’s disease (PD) is characterized by intracellular, insoluble Lewy bodies composed of highly stable α-synuclein (α-syn) amyloid fibrils. α-synuclein is an intrinsically disordered protein that has the capacity to assemble to form β-sheet rich fibrils. Oxidiative stress and metal rich environments have been implicated in triggering assembly. Here, we have explored the composition of Lewy bodies in post-mortem tissue using electron microscopy and immunogold labeling and revealed dityrosine crosslinks in Lewy bodies in brain tissue from PD patients. In vitro, we show that dityrosine cross-links in α-syn are formed by covalent ortho-ortho coupling of two tyrosine residues under conditions of oxidative stress by fluorescence and confirmed using mass-spectrometry. A covalently cross-linked dimer isolated by SDS-PAGE and mass analysis showed that dityrosine dimer was formed via the coupling of Y39-Y39 to give a homo dimer peptide that may play a key role in formation of oligomeric and seeds for fibril formation. Atomic force microscopy analysis reveals that the covalent dityrosine contributes to the stabilization of α-syn assemblies. Thus, the presence of oxidative stress induced dityrosine could play an important role in assembly and toxicity of α-syn in PD. PMID:27982082

  6. Consequences of intramolecular dityrosine formation on a DNA-protein complex: a molecular modeling study

    International Nuclear Information System (INIS)

    Gras, Julien; Sy, Denise; Eon, Severine; Charlier, Michel; Spotheim-Maurizot, Melanie

    2005-01-01

    Irradiation of the free lac repressor with γ-rays abolishes protein's ability to specifically bind operator DNA. A possible radiation-induced protein damage is a dityrosine (DTyr) formed by two spatially close radiation-induced tyrosyl radicals. We performed the molecular modeling of complexes between operator DNA and DTyr-bearing parts (headpieces) of the repressor. The presence of DTyr affects the structure and the interactions between partners. A detailed analysis allows to conclude this damage can partially account for the loss of repressor ability to bind DNA

  7. Opposed Effects of Dityrosine Formation in Soluble and Aggregated α-Synuclein on Fibril Growth.

    Science.gov (United States)

    Wördehoff, Michael M; Shaykhalishahi, Hamed; Groß, Luca; Gremer, Lothar; Stoldt, Matthias; Buell, Alexander K; Willbold, Dieter; Hoyer, Wolfgang

    2017-10-13

    Parkinson's disease is the second most common neurodegenerative disease. It is characterized by aggregation of the protein α-synuclein (α-syn) in Lewy bodies, mitochondrial dysfunction, and increased oxidative stress in the substantia nigra. Oxidative stress leads to several modifications of biomolecules including dityrosine (DiY) crosslinking in proteins, which has recently been detected in α-syn in Lewy bodies from Parkinson's disease patients. Here we report that α-syn is highly susceptible to ultraviolet-induced DiY formation. We investigated DiY formation of α-syn and nine tyrosine-to-alanine mutants and monitored its effect on α-syn fibril formation in vitro. Ultraviolet irradiation of intrinsically disordered α-syn generates DiY-modified monomers and dimers, which inhibit fibril formation of unmodified α-syn by interfering with fibril elongation. The inhibition depends on both the DiY group and its integration into α-syn. When preformed α-syn fibrils are crosslinked by DiY formation, they gain increased resistance to denaturation. DiY-stabilized α-syn fibrils retain their high seeding efficiency even after being exposed to denaturant concentrations that completely depolymerize non-crosslinked seeds. Oxidative stress-associated DiY crosslinking of α-syn therefore entails two opposing effects: (i) inhibition of aggregation by DiY-modified monomers and dimers, and (ii) stabilization of fibrillar aggregates against potential degradation mechanisms, which can lead to promotion of aggregation, especially in the presence of secondary nucleation. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  8. 76 FR 61042 - Modification of Regulations Regarding the Practice of Accepting Bonds During the Provisional...

    Science.gov (United States)

    2011-10-03

    ... Department of Commerce (the Department) is amending its regulations governing the effect of an affirmative... that explains the effects of an affirmative preliminary determination). This amendment reflects the... no hierarchy between cash and bond requirements for provisional measures, and that allowing the...

  9. Catch-slip bonds can be dispensable for motor force regulation during skeletal muscle contraction

    Science.gov (United States)

    Dong, Chenling; Chen, Bin

    2015-07-01

    It is intriguing how multiple molecular motors can perform coordinated and synchronous functions, which is essential in various cellular processes. Recent studies on skeletal muscle might have shed light on this issue, where rather precise motor force regulation was partly attributed to the specific stochastic features of a single attached myosin motor. Though attached motors can randomly detach from actin filaments either through an adenosine triphosphate (ATP) hydrolysis cycle or through "catch-slip bond" breaking, their respective contribution in motor force regulation has not been clarified. Here, through simulating a mechanical model of sarcomere with a coupled Monte Carlo method and finite element method, we find that the stochastic features of an ATP hydrolysis cycle can be sufficient while those of catch-slip bonds can be dispensable for motor force regulation.

  10. Hindered disulfide bonds to regulate release rate of model drug from mesoporous silica.

    Science.gov (United States)

    Nadrah, Peter; Maver, Uroš; Jemec, Anita; Tišler, Tatjana; Bele, Marjan; Dražić, Goran; Benčina, Mojca; Pintar, Albin; Planinšek, Odon; Gaberšček, Miran

    2013-05-01

    With the advancement of drug delivery systems based on mesoporous silica nanoparticles (MSNs), a simple and efficient method regulating the drug release kinetics is needed. We developed redox-responsive release systems with three levels of hindrance around the disulfide bond. A model drug (rhodamine B dye) was loaded into MSNs' mesoporous voids. The pore opening was capped with β-cyclodextrin in order to prevent leakage of drug. Indeed, in absence of a reducing agent the systems exhibited little leakage, while the addition of dithiothreitol cleaved the disulfide bonds and enabled the release of cargo. The release rate and the amount of released dye were tuned by the level of hindrance around disulfide bonds, with the increased hindrance causing a decrease in the release rate as well as in the amount of released drug. Thus, we demonstrated the ability of the present mesoporous systems to intrinsically control the release rate and the amount of the released cargo by only minor structural variations. Furthermore, an in vivo experiment on zebrafish confirmed that the present model delivery system is nonteratogenic.

  11. Untargeted metabolomics of colonic digests reveals kynurenine pathway metabolites, dityrosine and 3-dehydroxycarnitine as red versus white meat discriminating metabolites

    Science.gov (United States)

    Rombouts, Caroline; Hemeryck, Lieselot Y.; Van Hecke, Thomas; De Smet, Stefaan; De Vos, Winnok H.; Vanhaecke, Lynn

    2017-01-01

    Epidemiological research has demonstrated that the consumption of red meat is an important risk factor for the development of colorectal cancer (CRC), diabetes mellitus and cardiovascular diseases. However, there is no holistic insight in the (by-) products of meat digestion that may contribute to disease development. To address this hiatus, an untargeted mass spectrometry (MS)-based metabolomics approach was used to create red versus white meat associated metabolic fingerprints following in vitro colonic digestion using the fecal inocula of ten healthy volunteers. Twenty-two metabolites were unequivocally associated with simulated colonic digestion of red meat. Several of these metabolites could mechanistically be linked to red meat-associated pathways including N’-formylkynurenine, kynurenine and kynurenic acid (all involved in tryptophan metabolism), the oxidative stress marker dityrosine, and 3-dehydroxycarnitine. In conclusion, the used MS-based metabolomics platform proved to be a powerful platform for detection of specific metabolites that improve the understanding of the causal relationship between red meat consumption and associated diseases. PMID:28195169

  12. CD44 Binding to Hyaluronic Acid Is Redox Regulated by a Labile Disulfide Bond in the Hyaluronic Acid Binding Site.

    Directory of Open Access Journals (Sweden)

    Helena Kellett-Clarke

    Full Text Available CD44 is the primary leukocyte cell surface receptor for hyaluronic acid (HA, a component of the extracellular matrix. Enzymatic post translational cleavage of labile disulfide bonds is a mechanism by which proteins are structurally regulated by imparting an allosteric change and altering activity. We have identified one such disulfide bond in CD44 formed by Cys77 and Cys97 that stabilises the HA binding groove. This bond is labile on the surface of leukocytes treated with chemical and enzymatic reducing agents. Analysis of CD44 crystal structures reveal the disulfide bond to be solvent accessible and in the-LH hook configuration characteristic of labile disulfide bonds. Kinetic trapping and binding experiments on CD44-Fc chimeric proteins show the bond is preferentially reduced over the other disulfide bonds in CD44 and reduction inhibits the CD44-HA interaction. Furthermore cells transfected with CD44 no longer adhere to HA coated surfaces after pre-treatment with reducing agents. The implications of CD44 redox regulation are discussed in the context of immune function, disease and therapeutic strategies.

  13. 75 FR 52459 - Regulations Governing Agencies for Issue of United States Savings Bonds; Offering of United...

    Science.gov (United States)

    2010-08-26

    ... eliminate the option to purchase paper savings bonds through payroll deductions for United States government... savings bonds purchased through payroll sales; individuals will still be able to purchase paper savings bonds at financial institutions for themselves and as gifts. Payroll savers will be encouraged to...

  14. Exposure of tropoelastin to peroxynitrous acid gives high yields of nitrated tyrosine residues, di-tyrosine cross-links and altered protein structure and function

    DEFF Research Database (Denmark)

    Degendorfer, Georg; Chuang, Christine Yu-Nung; Mariotti, Michele

    2018-01-01

    Elastin is an abundant extracellular matrix protein in elastic tissues, including the lungs, skin and arteries, and comprises 30–57% of the aorta by dry mass. The monomeric precursor, tropoelastin (TE), undergoes complex processing during elastogenesis to form mature elastic fibres. Peroxynitrous......-protein di-tyrosine cross-links have been characterized by mass spectrometry. Examination of human atherosclerotic lesions shows colocalization of 3-nitroTyr with elastin epitopes, consistent with TE or elastin modification in vivo, and also an association of 3-nitroTyr containing proteins and elastin...

  15. Interfacial-Bonding-Regulated CO Oxidation over Pt Atoms Immobilized on Gas-Exfoliated Hexagonal Boron Nitride

    KAUST Repository

    Liu, Xin

    2017-10-12

    We compared the electronic structure and CO oxidation mechanisms over Pt atoms immobilized by both B-vacancies and N-vacancies on gas-exfoliated hexagonal boron nitride. We showed that chemical bonds are formed between the B atoms associated with dangling bonds around the vacancies and Pt atoms. These bonds not only alter the thermodynamics and kinetics for the aggregation and effectively immobilize Pt atoms, but also significantly change the composition and energetic distribution of the electronic states of the composites to circumvent CO poisoning and to favour coadsorption of CO and O2, which further regulates the reactions to proceed through a Langmuir-Hinshelwood mechanism. The CO oxidation over Pt atoms immobilized at N-vacancies involves formation of an intermediate with –C(O)-O−O- bonded to Pt, the generation of CO2 by peroxo O−O bond scission and the reduction of the remnant oxygen, and the calculated energy barriers are 0.49, 0.23 and 0.18 eV, respectively. Such small energy barriers are comparable to those over Pt atoms trapped at B-vacancies, showing the effectiveness of Pt/hexagonal boron nitride atomic composites as catalysts for CO oxidation. These findings also suggest the feasibility of regulating the reaction pathways over single atom catalysts via interfacial engineering.

  16. Quantification of urinary 0,0'-dityrosine, a biomarker for oxidative damage to proteins, by high performance liquid chromatography with triple quadrupole tandem mas spectrometry. A comparison with ion-trap tandem mass spectrometry.

    NARCIS (Netherlands)

    Orhan, H.; Coolen, S.; Meerman, J.H.N.

    2005-01-01

    We recently described an isotope dilution reversed-phase liquid chromatography-atmospheric pressure chemical ionization-ion-trap-tandem mass spectrometry (HPLC-APCI-MS/MS) method for the quantitative determination of oxidized amino acids in human urine, including o,o′-dityrosine, a specific marker

  17. 76 FR 23225 - Modification of Regulations Regarding the Practice of Accepting Bonds During the Provisional...

    Science.gov (United States)

    2011-04-26

    ... online at http://www.Regulations.gov and on the Department's Web site at http://www.trade.gov/ia/ . Any questions concerning file formatting, document conversion, access on the Internet, or other electronic... system, for the provisional measure period an estimated antidumping or countervailing duty rate is...

  18. Protein redox regulation in the thylakoid lumen: the importance of disulfide bonds for violaxanthin de-epoxidase.

    Science.gov (United States)

    Simionato, Diana; Basso, Stefania; Zaffagnini, Mirko; Lana, Tobia; Marzotto, Francesco; Trost, Paolo; Morosinotto, Tomas

    2015-04-02

    When exposed to saturating light conditions photosynthetic eukaryotes activate the xanthophyll cycle where the carotenoid violaxanthin is converted into zeaxanthin by the enzyme violaxanthin de-epoxidase (VDE). VDE protein sequence includes 13 cysteine residues, 12 of which are strongly conserved in both land plants and algae. Site directed mutagenesis of Arabidopsis thaliana VDE showed that all these 12 conserved cysteines have a major role in protein function and their mutation leads to a strong reduction of activity. VDE is also shown to be active in its completely oxidized form presenting six disulfide bonds. Redox titration showed that VDE activity is sensitive to variation in redox potential, suggesting the possibility that dithiol/disulfide exchange reactions may represent a mechanism for VDE regulation. Copyright © 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  19. Processes linking cultural ingroup bonds and mental health: the roles of social connection and emotion regulation

    OpenAIRE

    Roberts, Nicole A.; Burleson, Mary H.

    2013-01-01

    Cultural and ethnic identities influence the relationships individuals seek out and how they feel and behave in these relationships, which can strongly affect mental and physical health through their impacts on emotions, physiology, and behavior. We proposed and tested a model in which ethnocultural identifications and ingroup affiliations were hypothesized explicitly to enhance social connectedness, which would in turn promote expectancy for effective regulation of negative emotions and redu...

  20. Processes linking cultural ingroup bonds and mental health: the roles of social connection and emotion regulation.

    Science.gov (United States)

    Roberts, Nicole A; Burleson, Mary H

    2013-01-01

    Cultural and ethnic identities influence the relationships individuals seek out and how they feel and behave in these relationships, which can strongly affect mental and physical health through their impacts on emotions, physiology, and behavior. We proposed and tested a model in which ethnocultural identifications and ingroup affiliations were hypothesized explicitly to enhance social connectedness, which would in turn promote expectancy for effective regulation of negative emotions and reduce self-reported symptoms of depression and anxiety. Our sample comprised women aged 18-30 currently attending college in the Southwestern US, who self-identified as Hispanic of Mexican descent (MAs; n = 82) or as non-Hispanic White/European American (EAs; n = 234) and who completed an online survey. In the full sample and in each subgroup, stronger ethnocultural group identity and greater comfort with mainstream American culture were associated with higher social connectedness, which in turn was associated with expectancy for more effective regulation of negative emotions, fewer depressive symptoms, and less anxiety. Unexpectedly, preference for ingroup affiliation predicted lower social connectedness in both groups. In addition to indirect effects through social connection, direct paths from mainstream comfort and preference for ingroup affiliation to emotion regulation expectancy were found for EAs. Models of our data underscore that social connection is a central mechanism through which ethnocultural identities-including with one's own group and the mainstream cultural group-relate to mental health, and that emotion regulation may be a key aspect of this linkage. We use the term ethnocultural social connection to make explicit a process that, we believe, has been implied in the ethnic identity literature for many years, and that may have consequential implications for mental health and conceptualizations of processes underlying mental disorders.

  1. Processes linking cultural ingroup bonds and mental health: the roles of social connection and emotion regulation

    Science.gov (United States)

    Roberts, Nicole A.; Burleson, Mary H.

    2013-01-01

    Cultural and ethnic identities influence the relationships individuals seek out and how they feel and behave in these relationships, which can strongly affect mental and physical health through their impacts on emotions, physiology, and behavior. We proposed and tested a model in which ethnocultural identifications and ingroup affiliations were hypothesized explicitly to enhance social connectedness, which would in turn promote expectancy for effective regulation of negative emotions and reduce self-reported symptoms of depression and anxiety. Our sample comprised women aged 18–30 currently attending college in the Southwestern US, who self-identified as Hispanic of Mexican descent (MAs; n = 82) or as non-Hispanic White/European American (EAs; n = 234) and who completed an online survey. In the full sample and in each subgroup, stronger ethnocultural group identity and greater comfort with mainstream American culture were associated with higher social connectedness, which in turn was associated with expectancy for more effective regulation of negative emotions, fewer depressive symptoms, and less anxiety. Unexpectedly, preference for ingroup affiliation predicted lower social connectedness in both groups. In addition to indirect effects through social connection, direct paths from mainstream comfort and preference for ingroup affiliation to emotion regulation expectancy were found for EAs. Models of our data underscore that social connection is a central mechanism through which ethnocultural identities—including with one's own group and the mainstream cultural group—relate to mental health, and that emotion regulation may be a key aspect of this linkage. We use the term ethnocultural social connection to make explicit a process that, we believe, has been implied in the ethnic identity literature for many years, and that may have consequential implications for mental health and conceptualizations of processes underlying mental disorders. PMID:23450647

  2. Processes linking cultural ingroup bonds and mental health: The roles of social connection and emotion regulation

    Directory of Open Access Journals (Sweden)

    Nicole A Roberts

    2013-02-01

    Full Text Available Cultural and ethnic identities influence the relationships individuals seek out and how they feel and behave in these relationships, which can strongly affect mental and physical health through their impacts on emotions, physiology, and behavior. We proposed and tested a model in which ethnocultural identifications and ingroup affiliations were hypothesized explicitly to enhance social connectedness, which would in turn promote expectancy for effective regulation of negative emotions and reduce self-reported symptoms of depression and anxiety. Our sample comprised women aged 18 to 30 currently attending college in the Southwestern US, who self-identified as Hispanic of Mexican descent (n=82; MAs or as non-Hispanic White/European American (EAs; n=234 and who completed an online survey. In the full sample and in each subgroup, stronger ethnocultural group identity and greater comfort with mainstream American culture were associated with higher social connectedness, which in turn was associated with expectancy for more effective regulation of negative emotions, fewer depressive symptoms, and less anxiety. Unexpectedly, preference for ingroup affiliation predicted lower social connectedness in both groups. In addition to indirect effects through social connection, direct paths from mainstream comfort and preference for ingroup affiliation to emotion regulation expectancy were found for EAs. Models of our data underscore that social connection is a central mechanism through which ethnocultural identities—including with one’s own group and the mainstream cultural group—relate to mental health, and that emotion regulation may be a key aspect of this linkage. We use the term ethnocultural social connection to make explicit a process that, we believe, has been implied in the ethnic identity literature for many years, and that may have consequential implications for mental health and conceptualizations of processes underlying mental disorders.

  3. Isotope dependent, temperature regulated, energy repartitioning in a low-barrier, short-strong hydrogen bonded cluster

    NARCIS (Netherlands)

    Li, X. H.; Oomens, J.; Eyler, J. R.; Moore, D. T.; Iyengar, S. S.

    2010-01-01

    We investigate and analyze the vibrational properties, including hydrogen/deuterium isotope effects, in a fundamental organic hydrogen bonded system using multiple experimental (infrared multiple photon dissociation and argon-tagged action spectroscopy) and computational techniques. We note a

  4. Interfacial-Bonding-Regulated CO Oxidation over Pt Atoms Immobilized on Gas-Exfoliated Hexagonal Boron Nitride

    KAUST Repository

    Liu, Xin; Zhu, Hongdan; Linguerri, Roberto; Han, Yu; Chambaud, Gilberte; Meng, Changgong

    2017-01-01

    We compared the electronic structure and CO oxidation mechanisms over Pt atoms immobilized by both B-vacancies and N-vacancies on gas-exfoliated hexagonal boron nitride. We showed that chemical bonds are formed between the B atoms associated

  5. Roles of tyrosine-rich precursor glycoproteins and dityrosine- and 3,4-dihydroxyphenylalanine-mediated protein cross-linking in development of the oocyst wall in the coccidian parasite Eimeria maxima

    DEFF Research Database (Denmark)

    Belli, Sabina I; Wallach, Michael G; Luxford, Catherine

    2003-01-01

    infection by several organisms of medical and veterinary importance such as Eimeria, Plasmodium, Toxoplasma, Cyclospora, and Neospora could be developed. Here, we show that two tyrosine-rich precursor glycoproteins, gam56 and gam82, found in specialized organelles (wall-forming bodies) in the sexual stage...... (macrogamete) of Eimeria maxima are proteolytically processed into smaller glycoproteins, which are then incorporated into the developing oocyst wall. The identification of high concentrations of dityrosine and 3,4-dihydroxyphenylalanine (DOPA) in oocyst extracts by high-pressure liquid chromatography......-mediated cross-linking might be an enzyme-catalyzed event. As such, the mechanism of oocyst wall formation in Eimeria, is analogous to the underlying mechanisms involved in the stabilization of extracellular matrices in a number of organisms, widely distributed in nature, including insect resilin, nematode...

  6. Role of the brain dopaminergic and opioid system in the regulation of "child's" (maternal bonding) behavior of newborn albino rats.

    Science.gov (United States)

    Stovolosov, I S; Dubynin, V A; Kamensky, A A

    2011-01-01

    Administration of D(2) receptor antagonist clebopride in a dose not affecting locomotor activity was followed by a decrease in maternal bonding behavior of 10-day-old and 15-day-old albino rat pups. D(1) receptor antagonist SCH23390 had a stimulatory effect only on the behavior of 10-day-old newborns. Opioid peptide β-casomorphin-7 abolished the effect of clebopride in rat pups of the older age group.

  7. Zinc-coordinated MOFs complexes regulated by hydrogen bonds: Synthesis, structure and luminescence study toward broadband white-light emission

    Science.gov (United States)

    Duan, Hui; Dan, Wenyan; Fang, Xiangdong

    2018-04-01

    Two new compounds, namely {[Zn(apc)2]·H2O}n (1) and [Zn(apc)2(H2O)2] (2), have been designed and synthesized with a multi-functional ligand 2-aminopyrimidine-5-carboxylic acid (Hapc). Both compounds were characterized by single crystal X-ray diffraction analysis (SC-XRD), elemental analysis (EA), infrared spectroscopy (IR), and thermogravimetric analysis (TG). In solid-state structures, 1 features a two-fold interpenetrating pillared-layer 3D framework with point symbol {83}2{86}, referring to tfa topology; while 2 exhibits a 3D framework based on super unit of Zn(apc)2(H2O)2 interconnected via hydrogen bonds. Furthermore, the luminescent properties of 1 and 2 were discussed.

  8. 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…

  9. 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.

  10. 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...

  11. 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…

  12. 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

  13. Load regulating expansion fixture

    International Nuclear Information System (INIS)

    Wagner, L.M.; Strum, M.J.

    1998-01-01

    A free standing self contained device for bonding ultra thin metallic films, such as 0.001 inch beryllium foils is disclosed. The device will regulate to a predetermined load for solid state bonding when heated to a bonding temperature. The device includes a load regulating feature, whereby the expansion stresses generated for bonding are regulated and self adjusting. The load regulator comprises a pair of friction isolators with a plurality of annealed copper members located there between. The device, with the load regulator, will adjust to and maintain a stress level needed to successfully and economically complete a leak tight bond without damaging thin foils or other delicate components. 1 fig

  14. 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] ...

  15. Interplay of Electronic Cooperativity and Exchange Coupling in Regulating the Reactivity of Diiron(IV)-oxo Complexes towards C-H and O-H Bond Activation.

    Science.gov (United States)

    Ansari, Azaj; Ansari, Mursaleem; Singha, Asmita; Rajaraman, Gopalan

    2017-07-26

    Activation of inert C-H bonds such as those of methane are extremely challenging for chemists but in nature, the soluble methane monooxygenase (sMMO) enzyme readily oxidizes methane to methanol by using a diiron(IV) species. This has prompted chemists to look for similar model systems. Recently, a (μ-oxo)bis(μ-carboxamido)diiron(IV) ([Fe IV 2 O(L) 2 ] 2+ L=N,N-bis-(3',5'-dimethyl-4'-methoxypyridyl-2'-methyl)-N'-acetyl-1,2-diaminoethane) complex has been generated by bulk electrolysis and this species activates inert C-H bonds almost 1000 times faster than mononuclear Fe IV =O species and at the same time selectively activates O-H bonds of alcohols. The very high reactivity and selectivity of this species is puzzling and herein we use extensive DFT calculations to shed light on this aspect. We have studied the electronic and spectral features of diiron {Fe III -μ(O)-Fe III } +2 (complex I), {Fe III -μ(O)-Fe IV } +3 (II), and {Fe IV -μ(O)-Fe IV } +4 (III) complexes. Strong antiferromagnetic coupling between the Fe centers leads to spin-coupled S=0, S=3/2, and S=0 ground state for species I-III respectively. The mechanistic study of the C-H and O-H bond activation reveals a multistate reactivity scenario where C-H bond activation is found to occur through the S=4 spin-coupled state corresponding to the high-spin state of individual Fe IV centers. The O-H bond activation on the other hand, occurs through the S=2 spin-coupled state corresponding to an intermediate state of individual Fe IV centers. Molecular orbital analysis reveals σ-π/π-π channels for the reactivity. The nature of the magnetic exchange interaction is found to be switched during the course of the reaction and this offers lower energy pathways. Significant electronic cooperativity between two metal centers during the course of the reaction has been witnessed and this uncovers the reason behind the efficiency and selectivity observed. The catalyst is found to prudently choose the desired spin

  16. 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...

  17. 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

  18. 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] ...

  19. 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....

  20. 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...

  1. 48 CFR 53.301-25 - Performance Bond.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false Performance Bond. 53.301-25 Section 53.301-25 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION (CONTINUED) CLAUSES AND FORMS FORMS Illustrations of Forms 53.301-25 Performance Bond. ER18DE98.007 ER18DE98.008 [63...

  2. 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.

  3. 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...

  4. Regulation

    International Nuclear Information System (INIS)

    Ballereau, P.

    1999-01-01

    The different regulations relative to nuclear energy since the first of January 1999 are given here. Two points deserve to be noticed: the decree of the third august 1999 authorizing the national Agency for the radioactive waste management to install and exploit on the commune of Bures (Meuse) an underground laboratory destined to study the deep geological formations where could be stored the radioactive waste. The second point is about the uranium residues and the waste notion. The judgment of the administrative tribunal of Limoges ( 9. july 1998) forbidding the exploitation of a storage installation of depleted uranium considered as final waste and qualifying it as an industrial waste storage facility has been annulled bu the Court of Appeal. It stipulated that, according to the law number 75663 of the 15. july 1965, no criteria below can be applied to depleted uranium: production residue (possibility of an ulterior enrichment), abandonment of a personal property or simple intention to do it ( future use aimed in the authorization request made in the Prefecture). This judgment has devoted the primacy of the waste notion on this one of final waste. (N.C.)

  5. 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] ...

  6. 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 — ...

  7. 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 ...

  8. 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.

  9. 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

  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. 12 CFR 713.4 - What bond forms may be used?

    Science.gov (United States)

    2010-01-01

    ....4 Banks and Banking NATIONAL CREDIT UNION ADMINISTRATION REGULATIONS AFFECTING CREDIT UNIONS FIDELITY BOND AND INSURANCE COVERAGE FOR FEDERAL CREDIT UNIONS § 713.4 What bond forms may be used? (a) A... basic bond form; or (2) Any rider or endorsement that limits coverage of approved basic bond forms. [64...

  12. 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.

  13. 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...

  14. 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...

  15. 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...

  16. 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...

  17. 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.

  18. 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.

  19. 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

  20. 31 CFR 360.3 - Converting definitive savings bonds to book-entry bonds in New Treasury Direct.

    Science.gov (United States)

    2010-07-01

    ... Treasury Direct, an online system for holding Treasury securities. The Web address for New Treasury Direct... follow online instructions for conversion. Regulations governing converted bonds are found at 31 CFR part 363. [70 FR 14942, Mar. 23, 2005] ...

  1. 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.

  2. 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.

  3. 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...

  4. 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

  5. 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.

  6. 31 CFR 360.26 - Application for relief; after receipt of bond.

    Science.gov (United States)

    2010-07-01

    ... coowners, if living) authorized under the regulations in this part to request payment of the bond. In addition: (1) If the bond is in beneficiary form and the owner and beneficiary are both living, the... the application is approved, relief will be granted either by the issuance of a bond bearing the same...

  7. 48 CFR 452.232-70 - Reimbursement for Bond Premiums-Fixed-Price Construction Contracts.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Reimbursement for Bond... Provisions and Clauses 452.232-70 Reimbursement for Bond Premiums—Fixed-Price Construction Contracts. As prescribed in 432.111, insert the following clause: Reimbursement for Bond Premiums—Fixed-Price Construction...

  8. 31 CFR 317.7 - Obtaining and accounting for bond stock.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Obtaining and accounting for bond stock. 317.7 Section 317.7 Money and Finance: Treasury Regulations Relating to Money and Finance... AGENCIES FOR ISSUE OF UNITED STATES SAVINGS BONDS § 317.7 Obtaining and accounting for bond stock. An...

  9. 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...

  10. 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.

  11. 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-...

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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...

  17. 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...

  18. 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...

  19. 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...

  20. 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.

  1. 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

  2. Foreign bond markets and financial market development: International perspectives

    OpenAIRE

    Batten, Jonathan A.; Hogan, Warren P.; Szilagyi, Peter G.

    2009-01-01

    The domestic bond markets of the Asia and Pacific region have grown considerably since the Asian financial crisis of 1997, although they remain undeveloped relative to the region's weight in the world economy. This paper proposes that in order to encourage further development of these markets, regulators should make them more accessible to foreign borrowers. To that end we offer insights into the nature and mechanics of foreign bond issuance by investigating the key characteristics of 3,132 f...

  3. 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.

  4. 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...

  5. 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

  6. 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 ...

  7. 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.)

  8. 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.

  9. 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.

  10. 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....

  11. 31 CFR 363.95 - How may I give, and who can receive, a book-entry savings bond as a gift?

    Science.gov (United States)

    2010-07-01

    ... may give a book-entry savings bond as a gift in two ways: (a) An individual may purchase a book-entry..., a book-entry savings bond as a gift? 363.95 Section 363.95 Money and Finance: Treasury Regulations... DEBT REGULATIONS GOVERNING SECURITIES HELD IN TREASURYDIRECT Book-Entry Savings Bonds Purchased Through...

  12. 31 CFR 363.101 - Can an account owner transfer a book-entry savings bond to a minor?

    Science.gov (United States)

    2010-07-01

    ... REGULATIONS GOVERNING SECURITIES HELD IN TREASURYDIRECT Book-Entry Savings Bonds Purchased Through TreasuryDirect Gifts § 363.101 Can an account owner transfer a book-entry savings bond to a minor? An account owner can transfer a book-entry savings bond held in TreasuryDirect ® to a minor as a gift or pursuant...

  13. 29 CFR 2580.412-8 - The nature of the duties or activities to which the bonding requirement relates.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 9 2010-07-01 2010-07-01 false The nature of the duties or activities to which the bonding requirement relates. 2580.412-8 Section 2580.412-8 Labor Regulations Relating to Labor (Continued) EMPLOYEE... INCOME SECURITY ACT OF 1974 TEMPORARY BONDING RULES Scope and Form of the Bond § 2580.412-8 The nature of...

  14. 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...

  15. 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...

  16. Competing Intramolecular vs. Intermolecular Hydrogen Bonds in Solution

    Directory of Open Access Journals (Sweden)

    Peter I. Nagy

    2014-10-01

    Full Text Available A hydrogen bond for a local-minimum-energy structure can be identified according to the definition of the International Union of Pure and Applied Chemistry (IUPAC recommendation 2011 or by finding a special bond critical point on the density map of the structure in the framework of the atoms-in-molecules theory. Nonetheless, a given structural conformation may be simply favored by electrostatic interactions. The present review surveys the in-solution competition of the conformations with intramolecular vs. intermolecular hydrogen bonds for different types of small organic molecules. In their most stable gas-phase structure, an intramolecular hydrogen bond is possible. In a protic solution, the intramolecular hydrogen bond may disrupt in favor of two solute-solvent intermolecular hydrogen bonds. The balance of the increased internal energy and the stabilizing effect of the solute-solvent interactions regulates the new conformer composition in the liquid phase. The review additionally considers the solvent effects on the stability of simple dimeric systems as revealed from molecular dynamics simulations or on the basis of the calculated potential of mean force curves. Finally, studies of the solvent effects on the type of the intermolecular hydrogen bond (neutral or ionic in acid-base complexes have been surveyed.

  17. 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 ...

  18. 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.

  19. 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...

  20. 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

  1. 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

  2. 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.

  3. 31 CFR 363.96 - What do I need to know if I initially purchase a bond as a gift?

    Science.gov (United States)

    2010-07-01

    ... purchase a bond as a gift? 363.96 Section 363.96 Money and Finance: Treasury Regulations Relating to Money...Direct Gifts § 363.96 What do I need to know if I initially purchase a bond as a gift? (a) An entity may not purchase a gift savings bond. (b) The gift bond will be registered in the name of the recipient(s...

  4. 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

  5. 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.

  6. 7 CFR 1980.488 - Guaranteed industrial development bond issues.

    Science.gov (United States)

    2010-01-01

    ... industrial plants for lease to private businesses engaged in industrial manufacturing and does not provide... 7 Agriculture 14 2010-01-01 2009-01-01 true Guaranteed industrial development bond issues. 1980..., DEPARTMENT OF AGRICULTURE (CONTINUED) PROGRAM REGULATIONS (CONTINUED) GENERAL Business and Industrial Loan...

  7. 31 CFR 352.0 - Offering of bonds.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 2 2010-07-01 2010-07-01 false Offering of bonds. 352.0 Section 352.0 Money and Finance: Treasury Regulations Relating to Money and Finance (Continued) FISCAL SERVICE... terminate at the close of business on August 31, 2004. [69 FR 40318, July 2, 2004] ...

  8. Shear bond strength of self-etch and total-etch bonding systems at different dentin depths

    Directory of Open Access Journals (Sweden)

    Ana Carolina Maito Villela-Rosa

    2011-04-01

    Full Text Available The purpose of this study was to evaluate the dentin shear bond strength of four adhesive systems (Adper Single Bond 2, Adper Prompt L-Pop, Magic Bond DE and Self Etch Bond in regards to buccal and lingual surfaces and dentin depth. Forty extracted third molars had roots removed and crowns bisected in the mesiodistal direction. The buccal and lingual surfaces were fixed in a PVC/acrylic resin ring and were divided into buccal and lingual groups assigned to each selected adhesive. The same specimens prepared for the evaluation of superficial dentin shear resistance were used to evaluate the different depths of dentin. The specimens were identified and abraded at depths of 0.5, 1.0, 1.5 and 2.0 mm. Each depth was evaluated by ISO TR 11405 using an EMIC-2000 machine regulated at 0.5 mm/min with a 200 Kgf load cell. We performed statistical analyses on the results (ANOVA, Tukey and Scheffé tests. Data revealed statistical differences (p < 0.01 in the adhesive and depth variation as well as adhesive/depth interactions. The Adper Single Bond 2 demonstrated the highest mean values of shear bond strength. The Prompt L-Pop product, a self-etching adhesive, revealed higher mean values compared with Magic Bond DE and Self Etch Bond adhesives, a total and self-etching adhesive respectively. It may be concluded that the shear bond strength of dentin is dependent on material (adhesive system, substrate depth and adhesive/depth interaction.

  9. 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...

  10. 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.

  11. 31 CFR 363.176 - May a converted savings bond be pledged or used as collateral?

    Science.gov (United States)

    2010-07-01

    ... pledged or used as collateral? 363.176 Section 363.176 Money and Finance: Treasury Regulations Relating to... a converted savings bond be pledged or used as collateral? A converted savings bond may not be pledged or used as collateral for the performance of an obligation. ...

  12. 31 CFR 353.26 - Application for relief-After receipt of bond.

    Science.gov (United States)

    2010-07-01

    ... person or persons (including both coowners, if living) authorized under these regulations to request... both living, both will ordinarily be required to join in the application. (2) If a minor named on a... approved, relief will be granted either by the issuance of a bond bearing the same issue date as the bond...

  13. 26 CFR 6a.103A-1 - Interest on mortgage subsidy bonds.

    Science.gov (United States)

    2010-04-01

    ... interest on a mortgage subsidy bond is includable in gross income and subject to Federal income taxation... the regulations thereunder. (4) Advance refunding. On or after December 5, 1980, no tax-exempt obligation may be issued for the advance refunding of a mortgage subsidy bond (determined without regard to...

  14. 7 CFR 1720.14 - Nature of guarantee; acceleration of guaranteed bonds.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false Nature of guarantee; acceleration of guaranteed bonds. 1720.14 Section 1720.14 Agriculture Regulations of the Department of Agriculture (Continued) RURAL... TELEPHONE PURPOSES § 1720.14 Nature of guarantee; acceleration of guaranteed bonds. (a) Any guarantee...

  15. 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 ...

  16. 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...

  17. 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.

  18. 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.

  19. 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.

  20. 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)

  1. 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.

  2. 19 CFR Appendix D to Part 113 - Importer Security Filing Bond

    Science.gov (United States)

    2010-04-01

    ... manner prescribed in the CBP Regulations. This bond is executed on ________, 20______. SIGNED, SEALED AND DELIVERED IN THE PRESENCE OF: (Name)(Address) (Name)(Address) (Principal Name)(Seal) (Principal Address...

  3. 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)

  4. 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...

  5. Storage of hazardous substances in bonded warehouses

    International Nuclear Information System (INIS)

    Villalobos Artavia, Beatriz

    2008-01-01

    A variety of special regulations exist in Costa Rica for registration and transport of hazardous substances; these set the requirements for entry into the country and the security of transport units. However, the regulations mentioned no specific rules for storing hazardous substances. Tax deposits have been the initial place where are stored the substances that enter the country.The creation of basic rules that would be regulating the storage of hazardous substances has taken place through the analysis of regulations and national and international laws governing hazardous substances. The regulatory domain that currently exists will be established with a field research in fiscal deposits in the metropolitan area. The storage and security measures that have been used by the personnel handling the substances will be identified to be putting the reality with that the hazardous substances have been handled in tax deposits. A rule base for the storage of hazardous substances in tax deposits can be made, protecting the safety of the environment in which are manipulated and avoiding a possible accident causing a mess around. The rule will have the characteristics of the storage warehouses hazardous substances, such as safety standards, labeling standards, infrastructure features, common storage and transitional measures that must possess and meet all bonded warehouses to store hazardous substances. (author) [es

  6. "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.

  7. 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.

  8. 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

  9. 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...

  10. 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…

  11. 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…

  12. 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.

  13. 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.

  14. 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

  15. 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)

  16. 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...

  17. 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).

  18. 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.

  19. 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-...

  20. 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...

  1. 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

  2. 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].

  3. 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

  4. 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

  5. [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.

  6. 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,...

  7. 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.

  8. 76 FR 12364 - Agency Information Collection Activities: Bonded Warehouse Regulations

    Science.gov (United States)

    2011-03-07

    ... respondents or record keepers from the collection of information (a total capital/ startup costs and... Total Annual Responses: 9,254. Estimated Time per Response: 32 minutes. Estimated Total Annual Burden...

  9. IEE wiring regulations explained and illustrated

    CERN Document Server

    Scaddan, Brian

    2013-01-01

    The IEE Wiring Regulations Explained and Illustrated, Second Edition discusses the recommendations of the IEE Regulations for the Electrical Equipment of Buildings for the safe selection or erection of wiring installations. The book emphasizes earthing, bonding, protection, and circuit design of electrical wirings. The text reviews the fundamental requirements for safety, earthing systems, the earth fault loop impedance, and supplementary bonding. The book also describes the different types of protection, such as protection against mechanical damage, overcurrent, under voltage (which prevents

  10. 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...

  11. 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)

  12. 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)

  13. 78 FR 666 - Treasury Inflation-Protected Securities Issued at a Premium; Bond Premium Carryforward

    Science.gov (United States)

    2013-01-04

    ...-BL29 Treasury Inflation-Protected Securities Issued at a Premium; Bond Premium Carryforward AGENCY... contains final regulations that provide guidance on the tax treatment of Treasury Inflation-Protected... regulations in this document provide guidance to holders of Treasury Inflation-Protected Securities and other...

  14. 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....

  15. 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

  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. 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) ...

  20. 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...

  1. 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...

  2. 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

  3. 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...

  4. 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.

  5. 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...

  6. 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

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 31 CFR 363.58 - May book-entry savings bonds be pledged or used as collateral?

    Science.gov (United States)

    2010-07-01

    ... pledged or used as collateral? 363.58 Section 363.58 Money and Finance: Treasury Regulations Relating to...Direct General § 363.58 May book-entry savings bonds be pledged or used as collateral? Bonds may not be pledged or used as collateral for the performance of an obligation. ...

  13. 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.

  14. 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

  15. 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.

  16. 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....

  17. 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.

  18. 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.

  19. 19 CFR 122.134 - When airline does not have in-bond liquor storeroom.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false When airline does not have in-bond liquor storeroom. 122.134 Section 122.134 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Aircraft Liquor Kits § 122.134 When airline does not have in-bond liquor storeroom. (a...

  20. 19 CFR 122.135 - When airline has in-bond liquor storeroom.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false When airline has in-bond liquor storeroom. 122.135 Section 122.135 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY AIR COMMERCE REGULATIONS Aircraft Liquor Kits § 122.135 When airline has in-bond liquor storeroom. (a) Restocking. Liquor...

  1. 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...

  2. 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....

  3. Is 'green finance' actually green? 'Make The Planet Great Again' or 'Green-washing', we must choose. Report on green bonds and climate bonds

    International Nuclear Information System (INIS)

    Combes, Maxime; Plihon, Dominique; Zippert, Jean-Sebastien; Chaussalet, Alexis; Planche, Jeanne; Poulain, Melanie

    2017-12-01

    As Paris dreams of becoming the capital of green finance, the author proposes a discussion of the emerging market of green bonds, and formulates a set of recommendations for this new financial instrument not to be polluted by green-washing operations. He first describes what a green bond is, and then comments what the green bond market represents, discusses development perspectives for this market, comments the Paris dream of becoming the world capital of a green and sustainable finance. He explains why this green bond market appears to be so interesting, and what guarantees that a green bond will finance green projects. He discusses the role of rating agencies, whether the emitter of a green bond must be green, and the impact of green bonds on climate, on the environment and on populations. He discusses the possible evolution towards a constraining regulation, and examines whether this system can be an operational financing source for energy transition. Recommendations concern the market regulation by public authorities, the creation of a new rating agency for green finance, how to make the world bond market climate-compatible, and the creation of other financing channels for actors who have no access to the bond market

  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. 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

  8. 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

  9. 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.

  10. 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

  11. 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 ...

  12. 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...

  13. 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.

  14. 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...

  15. 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 ...

  16. 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...

  17. 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.

  18. 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

  19. 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

  20. 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. 

  1. 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.

  2. 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...

  3. 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.

  4. Mechanism Underlying Bonding Water Film Effect on Rheological Parameters

    Directory of Open Access Journals (Sweden)

    Yiyan Lv

    2016-01-01

    Full Text Available From experiments on bonding water of different slurries and the analysis of flow curves, the bilinear fluid model has been improved. The results showed that the rheological parameters correspond to physical processes at different stages of shear strain. As shear rate increases, slurries evolve from high-viscosity Bingham fluids to low-viscosity Bingham fluids. Specific surface area determines the number of edge-to-face arrangements; mineral composition influences the binding strength of each edge-to-face arrangement; and the volume fraction of particles regulates the distance between clay particles and number of edge-to-face arrangements.

  5. MUNICIPAL BONDS AS THE FINANCING STRATEGY FOR URBAN INFRASTRUCTURE : CASE STUDY OF JAKARTA MRT

    Directory of Open Access Journals (Sweden)

    Eko Nur Surachman

    2016-10-01

    Full Text Available The construction of Jakarta MRT Phase I has been carried out by using funds from foreign debt. Meanwhile, Jakarta MRT Phase II or other local infrastructure projects are still waiting for new funding scheme. One alternative is municipal bonds. This study investigate the possibilities of using municipal bonds to finance urban infrastructure project with the case study of Jakarta MRTPhase I. The analyzed use three perspectives including financial aspect, legal aspect, and Jakarta financial capacity aspect. financial analysis using discounted cash flow (DCF, net present value (NPV and internal rate of return (IRR.Secondly, study literature is used in the legal analysis by exploring specific regulations regarding the municipal bonds. Finally, the Jakarta Regional Budget and Jakarta Budget Audit Report is examined to get insight and depth information regarding its financial capacity. The result is municipal bonds are feasible as the source of financing Jakarta MRT Project.

  6. Tast Force report on bonding and perpetual care of nuclear licensed activities

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    Potential issues which should be considered prior to the adoption and implementation of a bonding or perpetual care program are examined. The following topics are discussed: problem definition; major processors; factors in setting the amount of a bond; waste handling licensees; ore refineries and mills; former AEC licensed facilities; other specific licenses; authority; states where it is deemed that amendment of existing statutes is necessary to authorize imposition of a bonding requirement for licenses; administration; and recommendations. The following appendices are included: summary of cost estimate to decontaminate the American Nuclear Company; report on 1974 national conference on radiation control workshop no. 3; suggested changes to state regulations; and suggested legislation for licensee bonding and perpetual care trust funds

  7. Regulating the Regulator

    Energy Technology Data Exchange (ETDEWEB)

    1992-08-26

    The article reports on a challenge to the UK electricity regulator to defend his record by the Coalition for Fair Electricity Regulation (COFFER). The challenge centres on whether the obligation for the regional electric companies (REC) to purchase power from the cheapest source is being enforced. This is related to the wider issue of whether the REC's support of combined-cycle gas turbine (CCGT) is economic. COFFER considers that uneconomic gas-fired power plants are being allowed to displace economic coal-fired stations. Aspects discussed include the background to the dispute and the costs of CCGT and coal fired power generation. 1 fig., 1 tab.

  8. 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.

  9. 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...

  10. 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

  11. 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...

  12. 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...

  13. 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

  14. 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, ...

  15. 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...

  16. 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

  17. 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...

  18. 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

  19. 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.

  20. 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

  1. 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...

  2. 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.

  3. 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...

  4. 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.

  5. 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

  6. 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.

  7. 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)

  8. 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.

  9. 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.

  10. Best-Estimates in Bond Markets with Reinvestment Risk

    Directory of Open Access Journals (Sweden)

    Anne MacKay

    2015-07-01

    Full Text Available The concept of best-estimate, prescribed by regulators to value insurance liabilities for accounting and solvency purposes, has recently been discussed extensively in the industry and related academic literature. To differentiate hedgeable and non-hedgeable risks in a general case, recent literature defines best-estimates using orthogonal projections of a claim on the space of replicable payoffs. In this paper, we apply this concept of best-estimate to long-maturity claims in a market with reinvestment risk, since in this case the total liability cannot easily be separated into hedgeable and non-hedgeable parts. We assume that a limited number of short-maturity bonds are traded, and derive the best-estimate price of bonds with longer maturities, thus obtaining a best-estimate yield curve. We therefore use the multifactor Vasiˇcek model and derive within this framework closed-form expressions for the best-estimate prices of long-term bonds.

  11. 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.

  12. 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....

  13. 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.

  14. 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...

  15. Loan versus Bond Financing of Czech Companies and the influence of the Global Recession

    Directory of Open Access Journals (Sweden)

    Mačí Jan

    2017-03-01

    Full Text Available European economies are traditionally considered to be bank based regarding the debt financing. However, in times of crises in the bank sector, this feature may indicate a weakness of these economies when the credit squeeze phenomenon may occur and companies’ competitiveness might be negatively affected thanks to unstable financing possibilities. In such conditions, a shift from bank loans to bonds might be expected. That is why this paper focuses on mutual development of corporate bond and business loan markets in the developing Czech economy in the years 2006–2014 with regard to the impacts of the global financial crisis of 2008/2009. The main goal of this article is to identify whether, thanks to the impacts of the global recession in 2009, there was a shift in Czech economy in business financing from the loans to bonds in a similar fashion as in the case of East Asian economies after their financial crisis in the nineties. Since Czech companies practically do not use short-term bonds, a mutual relationship is examined between amounts of long-term corporate bonds and economic development captured by the GDP per capita, and between long-term business loans and development of long-term corporate bonds. The main findings of this study are that since the global financial crisis, bond financing of businesses has been growing faster than loan financing. Czech economy thus shifts and becomes more bond market-based. The development of bond financing is positively correlated with the GDP per capita. Time series of both loans and bonds develop along the same trend. However, residual components are correlated negatively, which confirms the standing of loans and bonds as substitutes. Two main practical implications may be derived from this study. First, a growing usage of bonds increases demands on the market regulator, especially in the field of monitoring. Second, the growing bond market leads to the increased effectiveness, which makes additional

  16. 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.

  17. 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.

  18. 77 FR 31912 - Proposed Collection; Comment Request for Regulation Project

    Science.gov (United States)

    2012-05-30

    ... determining arbitrage profits. Under FI-7-94, the scope of interest rate hedging transactions covered by the... arbitrage restrictions on tax-exempt bonds. DATES: Written comments should be received on or before July 30...: Arbitrage Restrictions on Tax-Exempt Bonds. OMB Number: 1545-1347. Regulation Project Numbers: FI-36-92; FI...

  19. The Au/Si eutectic bonding compatibility with KOH etching for 3D devices fabrication

    Science.gov (United States)

    Liang, Hengmao; Liu, Mifeng; Liu, Song; Xu, Dehui; Xiong, Bin

    2018-01-01

    KOH etching and Au/Si eutectic bonding are cost-efficient technologies for 3D device fabrication. Aimed at investigating the process compatibility of KOH etching and Au/Si bonding, KOH etching tests have been carried out for Au/bulk Si and Au/amorphous Si (a-Si) bonding wafers in this paper. For the Au/bulk Si bonding wafer, a serious underetch phenomenon occurring on the damage layer in KOH etching definitely results in packaging failure. In the microstructure analysis, it is found that the formation of the damage layer between the bonded layer and bulk Si is attributed to the destruction of crystal Si lattices in Au/bulk Si eutectic reaction. Considering the occurrence of underetch for Au/Si bonding must meet two requirements: the superfluous Si and the defective layer near the bonded layer, the Au/a-Si bonding by regulating the a-Si/Au thickness ratio is presented in this study. Only when the a-Si/Au thickness ratio is relatively low are there not underetch phenomena, of which the reason is the full reaction of the a-Si layer avoiding the formation of the damage layer for easy underetch. Obviously, the Au/a-Si bonding via choosing a moderate a-Si/Au thickness ratio (⩽1.5:1 is suggested) could be reliably compatible with KOH etching, which provides an available and low-cost approach for 3D device fabrication. More importantly, the theory of the damage layer proposed in this study can be naturally applied to relevant analyses on the eutectic reaction of other metals and single crystal materials.

  20. 31 CFR 539.406 - Importation into and release from a bonded warehouse or foreign trade zone.

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Importation into and release from a bonded warehouse or foreign trade zone. 539.406 Section 539.406 Money and Finance: Treasury Regulations... WEAPONS OF MASS DESTRUCTION TRADE CONTROL REGULATIONS Interpretations § 539.406 Importation into and...

  1. 26 CFR 1.6851-3 - Furnishing of bond to insure payment; cross reference.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) INCOME TAX (CONTINUED) INCOME TAXES Additions to the Tax, Additional Amounts, and Assessable...-1 of this chapter (regulations on procedure and administration) for rules relating to the furnishing of bond to stay collection. [T.D. 7575, 43 FR 58817, Dec. 18, 1978] The Tax Court Declaratory...

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Market, Regulation, Market, Regulation

    DEFF Research Database (Denmark)

    Frankel, Christian; Galland, Jean-Pierre

    2015-01-01

    barriers to trade in Europe, realized the free movement of products by organizing progressively several orders of markets and regulation. Based on historical and institutional documents, on technical publications, and on interviews, this article relates how the European Commission and the Member States had......This paper focuses on the European Regulatory system which was settled both for opening the Single Market for products and ensuring the consumers' safety. It claims that the New Approach and Standardization, and the Global Approach to conformity assessment, which suppressed the last technical...... alternatively recourse to markets and to regulations, at the three main levels of the New Approach Directives implementation. The article focuses also more specifically on the Medical Devices sector, not only because this New Approach sector has long been controversial in Europe, and has recently been concerned...

  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. 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...

  11. 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

  12. 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.)

  13. Membrane fluctuations mediate lateral interaction between cadherin bonds

    Science.gov (United States)

    Fenz, Susanne F.; Bihr, Timo; Schmidt, Daniel; Merkel, Rudolf; Seifert, Udo; Sengupta, Kheya; Smith, Ana-Sunčana

    2017-09-01

    The integrity of living tissues is maintained by adhesion domains of trans-bonds formed between cadherin proteins residing on opposing membranes of neighbouring cells. These domains are stabilized by lateral cis-interactions between the cadherins on the same cell. However, the origin of cis-interactions remains perplexing since they are detected only in the context of trans-bonds. By combining experimental, analytical and computational approaches, we identify bending fluctuations of membranes as a source of long-range cis-interactions, and a regulator of trans-interactions. Specifically, nanometric membrane bending and fluctuations introduce cooperative effects that modulate the affinity and binding/unbinding rates for trans-dimerization, dramatically affecting the nucleation and growth of adhesion domains. Importantly, this regulation relies on physical principles and not on details of protein-protein interactions. These omnipresent fluctuations can thus act as a generic control mechanism in all types of cell adhesion, suggesting a hitherto unknown physiological role for recently identified active fluctuations of cellular membranes.

  14. 31 CFR 315.90 - Waiver of regulations.

    Science.gov (United States)

    2010-07-01

    ... SERVICE, DEPARTMENT OF THE TREASURY BUREAU OF THE PUBLIC DEBT REGULATIONS GOVERNING U.S. SAVINGS BONDS... persons of unnecessary hardship: (a) If such action would not be inconsistent with law or equity, (b) if...

  15. 31 CFR 360.90 - Waiver of regulations.

    Science.gov (United States)

    2010-07-01

    ... STATES SAVINGS BONDS, SERIES I Miscellaneous Provisions § 360.90 Waiver of regulations. The Commissioner... unnecessary hardship: (a) If such action would not be inconsistent with law or equity; (b) If it does not...

  16. 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.

  17. 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

  18. 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

  19. 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.

  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. 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...

  11. 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...

  12. 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,...

  13. 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.

  14. 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.

  15. 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.

  16. 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...

  17. 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.

  18. 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

  19. 29 CFR 453.11 - The nature of the “duties” to which the bonding requirement relates.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 2 2010-07-01 2010-07-01 false The nature of the âdutiesâ to which the bonding requirement relates. 453.11 Section 453.11 Labor Regulations Relating to Labor OFFICE OF LABOR-MANAGEMENT STANDARDS... LABOR-MANAGEMENT REPORTING AND DISCLOSURE ACT OF 1959 Scope of the Bond § 453.11 The nature of the...

  20. 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.

  1. 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.

  2. 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)

  3. 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.)

  4. 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.

  5. 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.

  6. 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), ...

  7. 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...

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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)

  13. 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)

  14. 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.

  15. The significance of disulfide bonding in biological activity of HB-EGF, a mutagenesis approach

    OpenAIRE

    Hoskins, J.T.; Zhou, Z.; Harding, P.A.

    2008-01-01

    A site-directed mutagenesis approach was taken to disrupt each of 3 disulfide bonds within human HB-EGF by substituting serine for both cysteine residues that contribute to disulfide bonding. Each HB-EGF disulfide analogue (HB-EGF-Cys/Ser108/121, HB-EGF-Cys/Ser116/132, and HB-EGF-Cys/Ser134/143) was cloned under the regulation of the mouse metallothionein (MT) promoter and stably expressed in mouse fibroblasts. HB-EGF immunoreactive proteins with Mr of 6.5, 21 and 24kDa were observed from lys...

  16. 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.

  17. 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)

  18. 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.

  19. 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...

  20. 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

  1. 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.

  2. 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...

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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.)

  17. 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.

  18. 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

  19. 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

  20. 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

  1. 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.

  2. 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...

  3. 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

  4. 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.

  5. 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

  6. 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...

  7. 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.

  8. 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.

  9. 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....

  10. 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.

  11. Biological aspects of social bonding and the roots of human violence.

    Science.gov (United States)

    Pedersen, Cort A

    2004-12-01

    The brain systems that motivate humans to form emotional bonds with others probably first evolved to mobilize the high-quality maternal care necessary for reproductive success in placental mammals. In these species, the helplessness of infants at birth and their dependence upon nutrition secreted from their mothers' bodies (milk) and parental body heat to stay warm required the evolution of a new motivational system in the brain to stimulate avid and sustained mothering behavior. Other types of social bonds that emerged subsequently in placental mammals, in particular monogamous bonds between breeding pairs, appear to have evolved from motivational brain systems that stimulate maternal behavior. This chapter focuses on aspects of the evolution and neurobiology of maternal and pair bonding and associated behavioral changes that may provide insights into the origins of human violence. The roles of the neuropeptides oxytocin and vasopressin as well as the neurotransmitter dopamine will be emphasized. Maternal and pair bonding are accompanied by increased aggressiveness toward perceived threats to the object of attachment as well as diminished fear and anxiety in stressful situations. The sustained closeness with mother required for the survival of infant mammals opened a new evolutionary niche in which aspects of the mother's care became increasingly important in regulating development in offspring. The quantity and quality of maternal care received during infancy determines adult social competence, ability to cope with stress, aggressiveness, and even preference for addictive substances. Indeed, the development of neurochemical systems within the brain that regulate mothering, aggression, and other types of social behavior, such as the oxytocin and vasopressin systems, are strongly affected by parental nurturing received during infancy. Evidence will be reviewed that the neural circuitry and neurochemistry implicated in studies of lower mammals also facilitate

  12. 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.

  13. 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...

  14. 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

  15. 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...

  16. 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.

  17. 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...

  18. Glass frit bonding with controlled width and height using a two-step wet silicon etching procedure

    Science.gov (United States)

    Yifang, Liu; Daner, Chen; Liwei, Lin; Gaofeng, Zheng; Jianyi, Zheng; Lingyun, Wang; Daoheng, Sun

    2016-03-01

    A simple and versatile two-step silicon wet etching technique for the control of the width and height of the glass frit bonding layer has been developed to improve bonding strength and reliability in wafer-level microelectromechanical systems (MEMS) packaging processes. The height of the glass frit bonding layer is set by the design of a vertical reference wall which regulates the distance between the silicon wafer and the encapsulation capping substrate. On the other hand, the width of the bonding layer is constrained between two micro grooves which are used to accommodate the spillages of extra glass frit during the bonding process. An optimized thermal bonding process, including the formation of glass liquid, removal of gas bubbles under vacuum and the filling of voids under normal atmospheric condition has been developed to suppress the formation of the bubbles/voids. The stencil printing and pre-sintering processes for the glass frit have been characterized before the thermal bonding process under different magnitudes of bonding pressure. The bonding gap thickness is found to be equal to the height of the reference wall of 10 μm in the prototype design. The bubbles/voids are found to be suppressed effectively and the bonding strength increases from 10.2 to 19.1 MPa as compared with a conventional thermal annealing process in air. Experimentally, prototype samples are measured to have passed the high hermetic sealing leakage tests of 5  ×  10-8 atm cc s-1.

  19. 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.

  20. 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)

  1. Pair-bonding, romantic love, and evolution: the curious case of Homo sapiens.

    Science.gov (United States)

    Fletcher, Garth J O; Simpson, Jeffry A; Campbell, Lorne; Overall, Nickola C

    2015-01-01

    This article evaluates a thesis containing three interconnected propositions. First, romantic love is a "commitment device" for motivating pair-bonding in humans. Second, pair-bonding facilitated the idiosyncratic life history of hominins, helping to provide the massive investment required to rear children. Third, managing long-term pair bonds (along with family relationships) facilitated the evolution of social intelligence and cooperative skills. We evaluate this thesis by integrating evidence from a broad range of scientific disciplines. First, consistent with the claim that romantic love is an evolved commitment device, our review suggests that it is universal; suppresses mate-search mechanisms; has specific behavioral, hormonal, and neuropsychological signatures; and is linked to better health and survival. Second, we consider challenges to this thesis posed by the existence of arranged marriage, polygyny, divorce, and infidelity. Third, we show how the intimate relationship mind seems to be built to regulate and monitor relationships. Fourth, we review comparative evidence concerning links among mating systems, reproductive biology, and brain size. Finally, we discuss evidence regarding the evolutionary timing of shifts to pair-bonding in hominins. We conclude there is interdisciplinary support for the claim that romantic love and pair-bonding, along with alloparenting, played critical roles in the evolution of Homo sapiens. © The Author(s) 2014.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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

  10. 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.

  11. 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 ...

  12. [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

  13. 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...

  14. 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.

  15. 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

  16. 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.

  17. 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…

  18. 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...

  19. 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.

  20. 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.

  1. 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

  2. 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…

  3. 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.

  4. 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...

  5. 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...

  6. 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...

  7. 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

  8. 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

  9. 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).

  10. 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...

  11. 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.

  12. 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.

  13. 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...

  14. 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…

  15. 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…

  16. 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...

  17. 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.

  18. Effects of Maternal Anxiety Disorders on Infant Self-Comforting Behaviors: The Role of Maternal Bonding, Infant Gender and Age.

    Science.gov (United States)

    Müller, Mitho; Tronick, Ed; Zietlow, Anna-Lena; Nonnenmacher, Nora; Verschoor, Stephan; Träuble, Birgit

    We investigated the links between maternal bonding, maternal anxiety disorders, and infant self-comforting behaviors. Furthermore, we looked at the moderating roles of infant gender and age. Our sample (n = 69) comprised 28 mothers with an anxiety disorder (according to DSM-IV criteria) and 41 controls, each with their 2.5- to 8-month-old infant (41 females and 28 males). Infant behaviors were recorded during the Face-to-Face Still-Face paradigm. Maternal bonding was assessed by the Postpartum Bonding Questionnaire. Conditional process analyses revealed that lower maternal bonding partially mediated between maternal anxiety disorders and increased self-comforting behaviors but only in older female infants (over 5.5 months of age). However, considering maternal anxiety disorders without the influence of bonding, older female infants (over 5.5 months of age) showed decreased rates of self-comforting behaviors, while younger male infants (under 3 months of age) showed increased rates in the case of maternal anxiety disorder. The results suggest that older female infants (over 5.5 months of age) are more sensitive to lower maternal bonding in the context of maternal anxiety disorders. Furthermore, results suggest a different use of self-directed regulation strategies for male and female infants of mothers with anxiety disorders and low bonding, depending on infant age. The results are discussed in the light of gender-specific developmental trajectories. © 2016 S. Karger AG, Basel.

  19. 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

  20. 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.

  1. 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.

  2. Formation of covalent di-tyrosine dimers in recombinant α-synuclein

    DEFF Research Database (Denmark)

    van Maarschalkerweerd, A; Pedersen, MN; Peterson, H

    2015-01-01

    in standard recombinant protein preparations, induced without extrinsic oxidative or nitrative agents. The dimers exhibit no secondary structure but advanced SAXS studies reveal an increased structural definition, resulting in a more hydrophobic micro-environment than the highly disordered monomer......Parkinson's disease is associated with fibril deposition in the diseased brain. Misfolding events of the intrinsically disordered synaptic protein α-synuclein are suggested to lead to the formation of transient oligomeric and cytotoxic species. The etiology of Parkinson's disease is further...

  3. 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.

  4. 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)

  5. 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.

  6. 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.

  7. 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.

  8. Radiation regulation

    International Nuclear Information System (INIS)

    Braithwaite, J.; Grabosky, P.

    1985-01-01

    The five main areas of radiation regulation considered are radiation exposure in the mining of uranium and other minerals, exposure in the use of uranium in nuclear reactors, risks in the transport of radioactive materials and hazards associated with the disposal of used materials. In Australia these problems are regulated by mines departments, the Australian Atomic Energy Commission and radiation control branches in state health departments. Each of these instutional areas of regulation is examined

  9. 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)

  10. 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...

  11. 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.

  12. Immobilization and bonding scheme of radioactive iodine-129 in silver tellurite glass

    Science.gov (United States)

    Lee, Cheong Won; Pyo, Jae-Young; Park, Hwan-Seo; Yang, Jae Hwan; Heo, Jong

    2017-08-01

    Silver tellurite glasses with melting temperatures disposal site. Iodine waste loading in glasses was as high as 12.64 wt% of all metallic elements and 11.21 wt% including oxygen. Normalized elemental releases obtained from the product consistency test were well below US regulation of 2 g/m2. Iodines are surrounded by four Ag+ ions forming [Ag4I]3+ units that are further connected to tellurite network through bonds with non-bridging oxygens.

  13. 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

  14. 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.

  15. 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

  16. 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

  17. 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.

  18. 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.

  19. Studying Chemical Reactions, One Bond at a Time, with Single Molecule AFM Techniques

    Science.gov (United States)

    Fernandez, Julio M.

    2008-03-01

    The mechanisms by which mechanical forces regulate the kinetics of a chemical reaction are unknown. In my lecture I will demonstrate how we use single molecule force-clamp spectroscopy and protein engineering to study the effect of force on the kinetics of thiol/disulfide exchange. Reduction of disulfide bond via the thiol/disulfide exchange chemical reaction is crucial in regulating protein function and is of common occurrence in mechanically stressed proteins. While reduction is thought to proceed through a substitution nucleophilic bimolecular (SN2) reaction, the role of a mechanical force in modulating this chemical reaction is unknown. We apply a constant stretching force to single engineered disulfide bonds and measure their rate of reduction by dithiothreitol (DTT). We find that while the reduction rate is linearly dependent on the concentration of DTT, it is exponentially dependent on the applied force, increasing 10-fold over a 300 pN range. This result predicts that the disulfide bond lengthens by 0.34 å at the transition state of the thiol/disulfide exchange reaction. In addition to DTT, we also study the reduction of the engineered disulfide bond by the E. coli enzyme thioredoxin (Trx). Thioredoxins are enzymes that catalyze disulfide bond reduction in all organisms. As before, we apply a mechanical force in the range of 25-450 pN to the engineered disulfide bond substrate and monitor the reduction of these bonds by individual enzymes. In sharp contrast with the data obtained with DTT, we now observe two alternative forms of the catalytic reaction, the first requiring a reorientation of the substrate disulfide bond, causing a shortening of the substrate polypeptide by 0.76±0.07 å, and the second elongating the substrate disulfide bond by 0.21±0.01 å. These results support the view that the Trx active site regulates the geometry of the participating sulfur atoms, with sub-ångström precision, in order to achieve efficient catalysis. Single molecule

  20. 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)

  1. 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.

  2. 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...

  3. 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...

  4. 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

  5. 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.

  6. 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.

  7. 75 FR 54191 - Pendency of Request for Exemption From the Bond/Escrow Requirement Relating to the Sale of Assets...

    Science.gov (United States)

    2010-09-03

    ... exemption from the bond/escrow requirement of section 4204(a)(1)(B) of the Employee Retirement Income... 4204 of the Employee Retirement Income Security Act of 1974, as amended by the Multiemployer Pension... not based on satisfaction of one of the four regulatory tests under regulation Sec. Sec. 4204.12 and...

  8. 78 FR 59228 - Sale and Issue of Marketable Book-Entry Treasury Bills, Notes, and Bonds; Corrections

    Science.gov (United States)

    2013-09-26

    ... and Issue of Marketable Book-Entry Treasury Bills, Notes, and Bonds; Corrections AGENCY: Fiscal... accommodate the public offering of floating rate notes. This document corrects the final regulations by.... Accordingly, 31 CFR part 356 is corrected by making the following correcting amendments: PART 356--SALE AND...

  9. 49 CFR Appendix A to Part 591 - Section 591.5(f) Bond for the Entry of a Single Vehicle

    Science.gov (United States)

    2010-10-01

    ... VEHICLES AND EQUIPMENT SUBJECT TO FEDERAL SAFETY, BUMPER AND THEFT PREVENTION STANDARDS Pt. 591, App. A Appendix A to Part 591—Section 591.5(f) Bond for the Entry of a Single Vehicle Department of Transportation... Vehicle A Appendix A to Part 591 Transportation Other Regulations Relating to Transportation (Continued...

  10. 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)

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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...

  18. 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.

  19. 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

  20. 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 ...

  1. 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.

  2. [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.

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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

  9. 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

  10. 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

  11. 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-.

  12. 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 ...

  13. 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...

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. 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

  3. 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 ...

  4. 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....

  5. 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 ...

  6. 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...

  7. 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 ...

  8. 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...

  9. 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,...

  10. 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…

  11. 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.

  12. 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

  13. 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.

  14. 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

  15. 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...

  16. 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

  17. 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...

  18. 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...

  19. 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...

  20. 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

  1. 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...

  2. 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...

  3. 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.

  4. 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.

  5. 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.

  6. Regulative environmental policy. Regulative Umweltpolitik

    Energy Technology Data Exchange (ETDEWEB)

    Goerlitz, A; Voigt, R [Universitaet der Bundeswehr Muenchen, Neubiberg (Germany, F.R.). Fakultaet fuer Sozialwissenschaften; eds.

    1991-01-01

    Regulative policy means those governmental attempts to steer the course of things which can fall back on a certain repertoire of instruments for actions in order to warrant the causal and temporal connection between the making available and the employment of means. The fact that environmental protection needs regulative policy is substantiated by the thesis that the market has failed; consequently only government can manage the public goods 'environment' in a suitable way, and it is a matter of fact that environmental protection at present is operated preferably via regulative policy. The problems of regulative enviromental policy are manifold. Its implementation often miscarries because of limited administrative resources on the one hand - making sufficient control impossible for instance -, and because of poor quality regulative instruments on the other hand. One way out would be to increase the efficiency of regulative policy by sophisticating judicial techniques. Other ways out point to the executing level and aim at improving implementation strategies or are concerned with post-regulative law. The latter refers to a new legal quality which demonstrates itself already in corporatistical crisis regulation or in induction programs such as pollution limits. A final way out favours deregulation strategies which includes the introduction of environmental levies or the allocation of environmental licences. An interdisciplinary discourse is to find out what would happen if these ways were taken. Pointers to solutions from varying scientific disciplines resulting from this discourse are to be found in this volume. (orig./HSCH).

  7. 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

  8. 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...

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. 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

  16. The Influences of Overlap Length, Bond Line Thickness and Pretreatmant on the Mechanical Properties of Adhesives : Focussing on Bonding Glass

    NARCIS (Netherlands)

    Vervloed, J.; Kwakernaak, A.; Poulis, H.

    2008-01-01

    This paper focuses on the influences of overlap length, bond line thickness and pretreatment on the mechanical properties of adhesive bonds. In order to determine the bond strength, lap shear tests were performed. The researched adhesives are a 2 component epoxy and MS polymer. The smallest overlap

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

    OpenAIRE

    Sandesh S Pai; Amrita Nagendra; Vinaya S Pai; K Neelima; A E Vishwanath; P Vinod; Sharanya Ajit Kumar; Roopa R Tubaki

    2012-01-01

    Introduction: Recent advances in the field of material sciences have opened up a new horizon of options for bonding agents that can be used efficiently in orthodontics. The purpose of this study was evaluate and compare the shear bond strength (SBS) of the traditionally used Transbond XT and a newer nano-filled material Prime and Bond NT. Materials and methods: Sixty freshly extracted maxillary first premolars were stored in 0.1% (weight/volume) thymol. These were divided into two Groups. ...

  18. Preliminary results for explosion bonding of beryllium to copper

    International Nuclear Information System (INIS)

    Butler, D.J.; Dombrowski, D.E.

    1995-01-01

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

  19. The CH/π hydrogen bond: Implication in chemistry

    Science.gov (United States)

    Nishio, M.

    2012-06-01

    The CH/π hydrogen bond is the weakest extreme of hydrogen bonds that occurs between a soft acid CH and a soft base π-system. Implication in chemistry of the CH/π hydrogen bond includes issues of conformation, crystal packing, and specificity in host/guest complexes. The result obtained by analyzing the Cambridge Structural Database is reviewed. The peculiar axial preference of isopropyl group in α-phellandrene and folded conformation of levopimaric acid have been explained in terms of the CH/π hydrogen bond, by high-level ab initio MO calculations. Implication of the CH/π hydrogen bond in structural biology is also discussed, briefly.

  20. Reliability improvement of wire bonds subjected to fatigue stresses.

    Science.gov (United States)

    Ravi, K. V.; Philofsky, E. M.

    1972-01-01

    The failure of wire bonds due to repeated flexure when semiconductor devices are operated in an on-off mode has been investigated. An accelerated fatigue testing apparatus was constructed and the major fatigue variables, aluminum alloy composition, and bonding mechanism, were tested. The data showed Al-1% Mg wires to exhibit superior fatigue characteristics compared to Al-1% Cu or Al-1% Si and ultrasonic bonding to be better than thermocompression bonding for fatigue resistance. Based on these results highly reliable devices were fabricated using Al-1% Mg wire with ultrasonic bonding which withstood 120,000 power cycles with no failures.

  1. Advances in modeling and design of adhesively bonded systems

    CERN Document Server

    Kumar, S

    2013-01-01

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

  2. Effect of Bonding Pressure and Bonding Time on the Tensile Properties of Cu-Foam / Cu-Plate Diffusion Bonded Joint

    International Nuclear Information System (INIS)

    Kim, Sang-Ho; Heo, Hoe-Jun; Kang, Chung-Yun; Yoon, Tae-Jin

    2016-01-01

    Open cell Cu foam, which has been widely utilized in various industries because of its high thermal conductivity, lightweight and large surface area, was successfully joined with Cu plate by diffusion bonding. To prevent excessive deformation of the Cu foam during bonding process, the bonding pressure should be lower than 500 kPa at 800 ℃ for 60 min and bonding pressure should be lowered with increasing holding time. The bonding strength was evaluated by tensile tests. The tensile load of joints increased with the bonding pressure and holding time. In the case of higher bonding pressure or time, the bonded length at the interface was usually longer than the cross-sectional length of the foam, so fracture occurred at the foam. For the same reason, base metal (foam) fracture mainly occurred at the node-plate junction rather than in the strut-plate junction because the bonded surface area of the node was relatively larger than that of the strut.

  3. Development of Statistical Process Control Methodology for an Environmentally Compliant Surface Cleaning Process in a Bonding Laboratory

    Science.gov (United States)

    Hutchens, Dale E.; Doan, Patrick A.; Boothe, Richard E.

    1997-01-01

    Bonding labs at both MSFC and the northern Utah production plant prepare bond test specimens which simulate or witness the production of NASA's Reusable Solid Rocket Motor (RSRM). The current process for preparing the bonding surfaces employs 1,1,1-trichloroethane vapor degreasing, which simulates the current RSRM process. Government regulations (e.g., the 1990 Amendments to the Clean Air Act) have mandated a production phase-out of a number of ozone depleting compounds (ODC) including 1,1,1-trichloroethane. In order to comply with these regulations, the RSRM Program is qualifying a spray-in-air (SIA) precision cleaning process using Brulin 1990, an aqueous blend of surfactants. Accordingly, surface preparation prior to bonding process simulation test specimens must reflect the new production cleaning process. The Bonding Lab Statistical Process Control (SPC) program monitors the progress of the lab and its capabilities, as well as certifies the bonding technicians, by periodically preparing D6AC steel tensile adhesion panels with EA-91 3NA epoxy adhesive using a standardized process. SPC methods are then used to ensure the process is statistically in control, thus producing reliable data for bonding studies, and identify any problems which might develop. Since the specimen cleaning process is being changed, new SPC limits must be established. This report summarizes side-by-side testing of D6AC steel tensile adhesion witness panels and tapered double cantilevered beams (TDCBs) using both the current baseline vapor degreasing process and a lab-scale spray-in-air process. A Proceco 26 inches Typhoon dishwasher cleaned both tensile adhesion witness panels and TDCBs in a process which simulates the new production process. The tests were performed six times during 1995, subsequent statistical analysis of the data established new upper control limits (UCL) and lower control limits (LCL). The data also demonstrated that the new process was equivalent to the vapor

  4. Bond markets and banking crises in emerging market economies: The role of institutions

    Directory of Open Access Journals (Sweden)

    Boukhatem Jamel

    2012-01-01

    Full Text Available This paper deals with the question of knowing if countries whose activity of financing is mainly bank based face crises more expensive than those where the bond markets are broader and more developed. The results of the empirical tests on a panel of emerging countries suggest that bank based financial systems are associated with crises slightly more expensive, whereas the relationship between the bond markets and the crises’ costs is fragile. Moreover, financial systems where bond markets play an important role are associated with a higher growth of the production, and this, independently of the presence or not of crises. The consideration of the combined effect of financial liberalization and institutional framework on the bond markets development shows the importance of the direction of the financial liberalization. We join in this case one of the most significant aspects of the “sequencing” theorized by McKinnon (1973. Finally, an effective prudential regulation tends to reduce significantly the probability of occurrence of banking crises.

  5. Solvent Bonding for Fabrication of PMMA and COP Microfluidic Devices.

    Science.gov (United States)

    Wan, Alwin M D; Moore, Thomas A; Young, Edmond W K

    2017-01-17

    Thermoplastic microfluidic devices offer many advantages over those made from silicone elastomers, but bonding procedures must be developed for each thermoplastic of interest. Solvent bonding is a simple and versatile method that can be used to fabricate devices from a variety of plastics. An appropriate solvent is added between two device layers to be bonded, and heat and pressure are applied to the device to facilitate the bonding. By using an appropriate combination of solvent, plastic, heat, and pressure, the device can be sealed with a high quality bond, characterized as having high bond coverage, bond strength, optical clarity, durability over time, and low deformation or damage to microfeature geometry. We describe the procedure for bonding devices made from two popular thermoplastics, poly(methyl-methacrylate) (PMMA), and cyclo-olefin polymer (COP), as well as a variety of methods to characterize the quality of the resulting bonds, and strategies to troubleshoot low quality bonds. These methods can be used to develop new solvent bonding protocols for other plastic-solvent systems.

  6. Pricing Chinese Convertible Bonds with Dynamic Credit Risk

    Directory of Open Access Journals (Sweden)

    Ping Li

    2014-01-01

    Full Text Available To price convertible bonds more precisely, least squares Monte Carlo (LSM method is used in this paper for its advantage in handling the dependence of derivatives on the path, and dynamic credit risk is used to replace the fixed one to make the value of convertible bonds reflect the real credit risk. In the empirical study, we price convertible bonds based on static credit risk and dynamic credit risk, respectively. Empirical results indicate that the ICBC convertible bond has been overpriced, resulting from the underestimation of credit risk. In addition, when there is an issue of dividend, the conversion price will change in China's convertible bonds, while it does not change in the international convertible bonds. So we also empirically study the difference between the convertible bond's prices by assuming whether the conversion price changes or not.

  7. How Do Organic Chemistry Students Understand and Apply Hydrogen Bonding?

    Science.gov (United States)

    Henderleiter, J.; Smart, R.; Anderson, J.; Elian, O.

    2001-08-01

    Students completing a year-long organic chemistry sequence were interviewed to assess how they understood, explained, and applied knowledge of hydrogen bonding to the physical behavior of molecules. Students were asked to define hydrogen bonding and explain situations in which hydrogen bonding could occur. They were asked to predict and explain how hydrogen bonding influences boiling point, the solubility of molecules, and NMR and IR spectra. Results suggest that although students may be able to give appropriate definitions of hydrogen bonding and may recognize when this phenomenon can occur, significant numbers cannot apply their knowledge of hydrogen bonding to physical properties of molecules or to the interpretation of spectral data. Some possess misconceptions concerning boiling points and the ability of molecules to induce hydrogen bonding. Instructional strategies must be adjusted to address these issues.

  8. Catch bonding in the forced dissociation of a polymer endpoint

    Science.gov (United States)

    Vrusch, Cyril; Storm, Cornelis

    2018-04-01

    Applying a force to certain supramolecular bonds may initially stabilize them, manifested by a lower dissociation rate. We show that this behavior, known as catch bonding and by now broadly reported in numerous biophysics bonds, is generically expected when either or both the trapping potential and the force applied to the bond possess some degree of nonlinearity. We enumerate possible scenarios and for each identify the possibility and, if applicable, the criterion for catch bonding to occur. The effect is robustly predicted by Kramers theory and Mean First Passage Time theory and confirmed in direct molecular dynamics simulation. Among the catch scenarios, one plays out essentially any time the force on the bond originates in a polymeric object, implying that some degree of catch bond behavior is to be expected in many settings relevant to polymer network mechanics or optical tweezer experiments.

  9. Cleavage of sp3 C-O bonds via oxidative addition of C-H bonds.

    Science.gov (United States)

    Choi, Jongwook; Choliy, Yuriy; Zhang, Xiawei; Emge, Thomas J; Krogh-Jespersen, Karsten; Goldman, Alan S

    2009-11-04

    (PCP)Ir (PCP = kappa(3)-C(6)H(3)-2,6-[CH(2)P(t-Bu)(2)](2)) is found to undergo oxidative addition of the methyl-oxygen bond of electron-poor methyl aryl ethers, including methoxy-3,5-bis(trifluoromethyl)benzene and methoxypentafluorobenzene, to give the corresponding aryloxide complexes (PCP)Ir(CH(3))(OAr). Although the net reaction is insertion of the Ir center into the C-O bond, density functional theory (DFT) calculations and a significant kinetic isotope effect [k(CH(3))(OAr)/k(CD(3))(OAr) = 4.3(3)] strongly argue against a simple insertion mechanism and in favor of a pathway involving C-H addition and alpha-migration of the OAr group to give a methylene complex followed by hydride-to-methylene migration to give the observed product. Ethoxy aryl ethers, including ethoxybenzene, also undergo C-O bond cleavage by (PCP)Ir, but the net reaction in this case is 1,2-elimination of ArO-H to give (PCP)Ir(H)(OAr) and ethylene. DFT calculations point to a low-barrier pathway for this reaction that proceeds through C-H addition of the ethoxy methyl group followed by beta-aryl oxide elimination and loss of ethylene. Thus, both of these distinct C-O cleavage reactions proceed via initial addition of a C(sp(3))-H bond, despite the fact that such bonds are typically considered inert and are much stronger than C-O bonds.

  10. Morphology, topography, and hardness of diffusion bonded sialon to AISI 420 at different bonding time

    Science.gov (United States)

    Ibrahim, Nor Nurulhuda Md.; Hussain, Patthi; Awang, Mokhtar

    2015-07-01

    Sialon and AISI 420 martensitic stainless steel were diffusion bonded in order to study the effect of bonding time on reaction layer's growth. Joining of these materials was conducted at 1200°C under a uniaxial pressure of 17 MPa in a vacuum ranging from 5.0 to 8.0×10-6 Torr with bonding time varied for 0.5, 2, and 3 h. Thicker reaction layer was formed in longer bonded sample since the elements from sialon could diffuse further into the steel. Sialon retained its microstructure but it was affected at the initial contact with the steel to form the new interface layer. Diffusion layer grew toward the steel and it was segregated with the parent steel as a result of the difference in properties between these regions. The segregation formed a stream-like structure and its depth decreased when the bonding time was increased. The microstructure of the steel transformed into large grain size with precipitates. Prolonging the bonding time produced more precipitates in the steel and reduced the steel thickness as well. Interdiffusions of elements occurred between the joined materials and the concentrations were decreasing toward the steel and vice versa. Silicon easily diffused into the steel because it possessed lower ionization potential compared to nitrogen. Formation of silicide and other compounds such as carbides were detected in the interface layer and steel grain boundary, respectively. These compounds were harmful due to silicide brittleness and precipitation of carbides in the grain boundary might cause intergranular corrosion cracking. Sialon retained its hardness but it dropped very low at the interface layer. The absence of crack at the joint in all samples could be contributed from the ductility characteristic of the reaction layer which compensated the residual stress that was formed upon the cooling process.

  11. Enamel shear bond strength of two orthodontic self-etching bonding systems compared to Transbond™ XT.

    Science.gov (United States)

    Hellak, Andreas; Rusdea, Patrick; Schauseil, Michael; Stein, Steffen; Korbmacher-Steiner, Heike Maria

    2016-11-01

    The aim of this in vitro study was to compare the shear bond strength (SBS) and Adhesive Remnant Index (ARI) scores of two self-etching no-mix adhesives (Prompt L-Pop™ and Scotchbond™) for orthodontic appliances to the commonly used total etch system Transbond XT™ (in combination with phosphoric acid). In all, 60 human premolars were randomly divided into three groups of 20 specimens each. In group 1 (control), brackets were bonded with Transbond™ XT primer. Prompt L-Pop™ (group 2) and Scotchbond™ Universal (group 3) were used in the experimental groups. Lower premolar brackets were bonded by light curing the adhesive. After 24 h of storage, the shear bond strength (SBS) was measured using a Zwicki 1120 testing machine. The adhesive remnant index (ARI) was determined under 10× magnification. The Kruskal-Wallis test was used to statistically compare the SBS and the ARI scores. No significant differences in the SBS between any of the experimental groups were detected (group 1: 15.49 ± 3.28 MPa; group 2: 13.89 ± 4.95 MPa; group 3: 14.35 ± 3.56 MPa; p = 0.489), nor were there any significant differences in the ARI scores (p = 0.368). Using the two self-etching no-mix adhesives (Prompt L-Pop™ and Scotchbond™) for orthodontic appliances does not affect either the SBS or ARI scores in comparison with the commonly used total-etch system Transbond™ XT. In addition, Scotchbond™ Universal supports bonding on all types of surfaces (enamel, metal, composite, and porcelain) with no need for additional primers. It might therefore be helpful for simplifying bonding in orthodontic procedures.

  12. Microtensile bond strength of silorane-based composite specific adhesive system using different bonding strategies

    OpenAIRE

    Bastos, Laura Alves; Sousa, Ana Beatriz Silva; Drubi-Filho, Brahim; Panzeri Pires-de-Souza, Fernanda de Carvalho; Garcia, Lucas da Fonseca Roberti

    2014-01-01

    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/S...

  13. Fracture surface analysis in composite and titanium bonding: Part 1: Titanium bonding

    Science.gov (United States)

    Sanderson, K. A.; Wightman, J. P.

    1985-01-01

    Fractured lap shear Ti 6-4 adherends bonded with polyphenyquinoxaline (PPQ) and polysulfone were analyzed. The effects of adherend pretreatment, stress level, thermal aging, anodizing voltage, and modified adhesive of Ti 6-4 adherend bonded with PPQ on lap shear strength were studied. The effect of adherend pretreatment on lap shear strength was investigated for PS samples. Results of scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) used to study the surface topography and surface composition are also discussed.

  14. A comparison of shear bond strength of orthodontic brackets bonded with four different orthodontic adhesives

    Science.gov (United States)

    Sharma, Sudhir; Tandon, Pradeep; Nagar, Amit; Singh, Gyan P; Singh, Alka; Chugh, Vinay K

    2014-01-01

    Objectives: The objective of this study is to compare the shear bond strength (SBS) of stainless steel (SS) orthodontic brackets bonded with four different orthodontic adhesives. Materials and Methods: Eighty newly extracted premolars were bonded to 0.022 SS brackets (Ormco, Scafati, Italy) and equally divided into four groups based on adhesive used: (1) Rely-a-Bond (self-cure adhesive, Reliance Orthodontic Product, Inc., Illinois, USA), (2) Transbond XT (light-cure adhesive, 3M Unitek, CA, USA), (3) Transbond Plus (sixth generation self-etch primer, 3M Unitek, CA, USA) with Transbond XT (4) Xeno V (seventh generation self-etch primer, Dentsply, Konstanz, Germany) with Xeno Ortho (light-cure adhesive, Dentsply, Konstanz, Germany) adhesive. Brackets were debonded with a universal testing machine (Model No. 3382 Instron Corp., Canton, Mass, USA). The adhesive remnant index (ARI) was recordedIn addition, the conditioned enamel surfaces were observed under a scanning electron microscope (SEM). Results: Transbond XT (15.49 MPa) attained the highest bond strength. Self-etching adhesives (Xeno V, 13.51 MPa; Transbond Plus, 11.57 MPa) showed clinically acceptable SBS values and almost clean enamel surface after debonding. The analysis of variance (F = 11.85, P adhesives left on the tooth) to be the most prevalent in Transbond XT (40%), followed by Rely-a-Bond (30%), Transbond Plus with Transbond XT (15%), and Xeno V with Xeno Ortho (10%). Under SEM, enamel surfaces after debonding of the brackets appeared porous when an acid-etching process was performed on the surfaces of Rely-a-Bond and Transbond XT, whereas with self-etching primers enamel presented smooth and almost clean surfaces (Transbond Plus and Xeno V group). Conclusion: All adhesives yielded SBS values higher than the recommended bond strength (5.9-7–8 MPa), Seventh generation self-etching primer Xeno V with Xeno Ortho showed clinically acceptable SBS and the least amount of residual adhesive left on the

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

    Directory of Open Access Journals (Sweden)

    Yasini E.

    2005-05-01

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

  16. The choice among non-callable bonds and make whole, claw back and otherwise ordinary callable bonds

    OpenAIRE

    Booth, LD; Gounopoulos, D; Skinner, F

    2012-01-01

    This paper seeks to explain determinates of the choice and the pricing of various types of callable and non-callable bonds. We find that the popularity of different types of callable and non-callable bonds is significantly related to the economic environment. In addition, the popularity of claw back bonds appear to be driven by agency considerations, make whole bonds by the debt overhang problem, ordinary callable bonds by the need by banks to deal with interest rate changes and non-callable ...

  17. Superconductivity and the magnetic electron bond

    International Nuclear Information System (INIS)

    Szurek, P.

    1989-01-01

    The concept of the magnetic electron bond as the fundamental characteristic of superconductivity was first introduced during a presentation at the 1988 Winter Annual Meeting of the American Society of Mechanical Engineers. Postulates describing the role of the electron and the magnetic bond were suggested to explain in a consistent manner known observations. What may becoming clear is that a boundary set of conditions may exist above and below the transition temperature at which a material superconducts. Prior to recent history, scientists have concentrated on postulating, experimenting, and learning about the set of conditions that exist above the transition temperature, which has set the standard for todays quantum theory. Above the transition temperature they have learned about the interrelationships that exist between the electron, a small magnetic and negatively charged body, and the nucleus, a large positively charged body. By grouping common general characteristics due to the interaction between the outer shell electrons and the nucleus of different elements, three bond types have been established, covalent, ionic, and metallic. They may now be in the process of determining those conditions that lie below the transition temperature, a realm where charge effects may no longer dominate magnetic effects. This may involve updating the quantum theory to reflect those conditions that exist above and below the transition temperature. The following discussion reviews, updates, and attempts to answer some preliminary questions regarding postulates that may define some of the conditions that lie below the transition temperature. As an introduction, figure 1 depicts what may occur to loosely held outer shell electrons below the transition temperature due to increased inner electron shielding. 7 refs., 9 figs

  18. Bond selective chemistry beyond the adiabatic approximation

    Energy Technology Data Exchange (ETDEWEB)

    Butler, L.J. [Univ. of Chicago, IL (United States)

    1993-12-01

    One of the most important challenges in chemistry is to develop predictive ability for the branching between energetically allowed chemical reaction pathways. Such predictive capability, coupled with a fundamental understanding of the important molecular interactions, is essential to the development and utilization of new fuels and the design of efficient combustion processes. Existing transition state and exact quantum theories successfully predict the branching between available product channels for systems in which each reaction coordinate can be adequately described by different paths along a single adiabatic potential energy surface. In particular, unimolecular dissociation following thermal, infrared multiphoton, or overtone excitation in the ground state yields a branching between energetically allowed product channels which can be successfully predicted by the application of statistical theories, i.e. the weakest bond breaks. (The predictions are particularly good for competing reactions in which when there is no saddle point along the reaction coordinates, as in simple bond fission reactions.) The predicted lack of bond selectivity results from the assumption of rapid internal vibrational energy redistribution and the implicit use of a single adiabatic Born-Oppenheimer potential energy surface for the reaction. However, the adiabatic approximation is not valid for the reaction of a wide variety of energetic materials and organic fuels; coupling between the electronic states of the reacting species play a a key role in determining the selectivity of the chemical reactions induced. The work described below investigated the central role played by coupling between electronic states in polyatomic molecules in determining the selective branching between energetically allowed fragmentation pathways in two key systems.

  19. All-ceramic crowns: bonding or cementing?

    Science.gov (United States)

    Pospiech, Peter

    2002-12-01

    Despite the wide variety of all-ceramic systems available today, the majority of dental practitioners hesitate to recommend and insert all-ceramic crowns. This article regards the nature of the ceramic materials, the principles of bonding and adhesion, and the clinical problems of the acid-etch technique for crowns. Advantages and disadvantages are discussed, and the influences of different factors on the strength of all-ceramic crowns are presented. Finally, the conclusion is drawn that conventional cementing of all-ceramic crowns is possible when the specific properties of the ceramics are taken into consideration.

  20. Topological Qubits from Valence Bond Solids

    Science.gov (United States)

    Wang, Dong-Sheng; Affleck, Ian; Raussendorf, Robert

    2018-05-01

    Topological qubits based on S U (N )-symmetric valence-bond solid models are constructed. A logical topological qubit is the ground subspace with twofold degeneracy, which is due to the spontaneous breaking of a global parity symmetry. A logical Z rotation by an angle 2 π /N , for any integer N >2 , is provided by a global twist operation, which is of a topological nature and protected by the energy gap. A general concatenation scheme with standard quantum error-correction codes is also proposed, which can lead to better codes. Generic error-correction properties of symmetry-protected topological order are also demonstrated.