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Sample records for adper easy bond

  1. The Effect of Temperature on Shear Bond Strength of Clearfil SE Bond and Adper Single Bond Adhesive Systems to Dentin

    PubMed Central

    Sharafeddin, Farahnaz; Nouri, Hossein; Koohpeima, Fatemeh

    2015-01-01

    Statement of the Problem Monomer viscosity and solvent evaporation can be affected by the adhesive system temperature. Higher temperature can elevate the vapor pressure in solution and penetration of adhesive in smear layer. Bonding mechanism may be influenced by the adhesive temperature. Purpose This study aimed to evaluate the effect of pre-heating on shear bond strength of etch-and-rinse and self-etching adhesives to ground bovine dentin surfaces, at temperatures of 4˚C, 25˚C and 40˚C. Materials and Method In this experimental study, 60 maxillary bovine incisors were randomly divided into 6 groups (n=10). The central part of labial dentin surfaces was exposed with a diamond bur and standardized smear layer was created by using silicon carbide paper (600 grit) under water-coolant while the specimens were mounted in acrylic resin. Two adhesive systems, an etch-and-rinse (Adper single bond) and a self-etch (Clearfil SE Bond) were stored at temperatures of 4˚C, 25˚C and 40˚C for 30 minutes and were then applied on the prepared labial surface according to the manufacturer’s instructions. The composite resin (Z350) was packed in Teflon mold (5 mm in diameter) on this surface and was cured. The shear bond strength (MPa) was evaluated by universal testing machine (Zwick/Roell Z020, Germany) at cross head speed of 1mm/min. The results were statistically analyzed by using ANOVA and Tukey tests (p< 0.05). Results No significant difference was found between the shear bond strength of Clearfil SE Bond adhesive in different temperature and single Bond adhesive system at 25 ˚C and 40 ˚C. However, there were significant differences between 4 ˚C of Adper single bond in comparison with 25˚C and 40˚C (p= 0.0001). Conclusion Pre-heating did not affect the shear bond strength of SE Bond, but could promote the shear bond strength of Adper Single Bond. PMID:25759852

  2. Influence of preliminary etching on the stability of bonds created by one-step self-etch bonding systems.

    PubMed

    Taschner, Michael; Nato, Fernando; Mazzoni, Annalisa; Frankenberger, Roland; Falconi, Mirella; Petschelt, Anselm; Breschi, Lorenzo

    2012-06-01

    We evaluated the effects of preliminary etching of dentine on the stability of the bond created by one-step self-etch adhesives under different storage conditions. Adper Easy Bond (3M ESPE) and iBond Self-Etch (iBond SE; Heraeus Kulzer) were applied with an etch-and-rinse (i.e. after preliminary phosphoric acid etching for 15 s) or a self-etch approach. Resin-dentine bonded specimens were sectioned perpendicularly to the adhesive interface according to the 'non-trimming technique'. Beams were stored in artificial saliva for 24 h, 6 months, or 1 yr at 37°C, or in 10% NaOCl for 5 h at room temperature, and then stressed until failure; the microtensile bond strengths were calculated. Interfacial nanoleakage of additional teeth was evaluated using light microscopy or transmission electron microscopy. Adper Easy Bond showed higher bond strength than iBond SE, regardless of the dentine treatment. Similar microtensile bond strength results were obtained for teeth subjected to artificial ageing in 10% NaOCl for 5 h at room temperature and for teeth stored in artificial saliva for 6 months at 37°C. The additional etching step increased the microtensile bond strength for Adper Easy Bond and iBond SE. This study supports the use of one-step adhesives on etched dentine because of the increased bond strength compared with their application onto smear-layer-covered dentine, regardless of storage conditions. PMID:22607341

  3. Micro pinball game demonstrating an easy MEMS transfer process using room temperature plasma bonding

    NASA Astrophysics Data System (ADS)

    Bring, Martin; Sanz-Velasco, Anke; Rödjegård, Henrik; Enoksson, Peter

    2003-07-01

    An easy wafer level transfer process for fabrication of electrostatically actuated structures such as bulk micromachined motors or cantilevers is described. The actual structures were fabricated by dry etching of a donor wafer, transferred to a handling wafer using room temperature oxygen plasma assisted bonding and then revealed through etchback of the donor wafer. Notching during the dry etch was avoided since there is no need for a buried oxide etch stop layer. Etch depth differences after the dry etch were eliminated in the etchback step. The process was used to fabricate MEMS demonstrators in the form of micro pinball games and microelectromechanical wobble motors. This process is a low cost alternative to using SOI wafers and it also circumvents some of the problems of deep dry etching that arise when using buried etch stop layers as in the case of SOI wafers. Another advantage of using SOI wafers is that double-sided micromachining becomes less complicated.

  4. Effect of prolonged air drying on the bond strength of adhesive systems to dentin.

    PubMed

    Werle, Stefanie Bressan; Steglich, Ana; Soares, Fabio Zovico Maxnuck; Rocha, Rachel Oliveira

    2015-01-01

    This in vitro study evaluated the effect of air-drying time on degree of solvent evaporation (DE), dentin microtensile bond strength (µTBS), and degree of conversion (DC) of 5 adhesive systems: Adper Single Bond 2, XP Bond, Prime & Bond 2.1, OptiBond Solo, and Adper Easy One. For DE testing, 20 µL of each material was submitted to measurements in a digital balance after an air stream of 3, 5, 10, 20, 30, or 60 seconds; the weight loss was computed and converted to a percentage (DE). For µTBS testing, 50 sound human molars were divided into groups (n = 5). The 5 adhesive systems were applied either in accordance with manufacturers' instructions for solvent drying time (control) or with a prolonged drying time (20-30 seconds). After composite resin was built up on the hybridized surfaces, the teeth were stored for 24 hours and then sectioned to obtain beams that were loaded until fracture. For DC testing, specimens of each adhesive and air-drying condition (n = 3) were evaluated by means of attenuated total reflectance Fourier transform infrared spectroscopy. Data were submitted to 2-way analysis of variance, t test, and Spearman test for correlation analysis. Prolonged air drying resulted in significantly greater DE than did the time suggested by the manufacturers. The adhesives XP Bond and Adper Easy One showed significantly greater µTBS with prolonged air drying. The DC was not affected by air-drying time. No statistically significant correlation was found between DC and µTBS values. Depending on the material, bond strength can be improved by prolonged air-drying times.

  5. Effect of prolonged air drying on the bond strength of adhesive systems to dentin.

    PubMed

    Werle, Stefanie Bressan; Steglich, Ana; Soares, Fabio Zovico Maxnuck; Rocha, Rachel Oliveira

    2015-01-01

    This in vitro study evaluated the effect of air-drying time on degree of solvent evaporation (DE), dentin microtensile bond strength (µTBS), and degree of conversion (DC) of 5 adhesive systems: Adper Single Bond 2, XP Bond, Prime & Bond 2.1, OptiBond Solo, and Adper Easy One. For DE testing, 20 µL of each material was submitted to measurements in a digital balance after an air stream of 3, 5, 10, 20, 30, or 60 seconds; the weight loss was computed and converted to a percentage (DE). For µTBS testing, 50 sound human molars were divided into groups (n = 5). The 5 adhesive systems were applied either in accordance with manufacturers' instructions for solvent drying time (control) or with a prolonged drying time (20-30 seconds). After composite resin was built up on the hybridized surfaces, the teeth were stored for 24 hours and then sectioned to obtain beams that were loaded until fracture. For DC testing, specimens of each adhesive and air-drying condition (n = 3) were evaluated by means of attenuated total reflectance Fourier transform infrared spectroscopy. Data were submitted to 2-way analysis of variance, t test, and Spearman test for correlation analysis. Prolonged air drying resulted in significantly greater DE than did the time suggested by the manufacturers. The adhesives XP Bond and Adper Easy One showed significantly greater µTBS with prolonged air drying. The DC was not affected by air-drying time. No statistically significant correlation was found between DC and µTBS values. Depending on the material, bond strength can be improved by prolonged air-drying times. PMID:26545278

  6. Influence of salivary contamination on the dentin bond strength of two different seventh generation adhesive systems: In vitro study

    PubMed Central

    Bhatia, Taranjeet Kaur; Asrani, Hemant; Banga, Harpreet; Jain, Aditi; Rawlani, Sudhir S.

    2015-01-01

    Aim: To investigate the effect of salivary contamination on the bond strength of two different seventh generation adhesive systems. Materials and Methods: Sixty caries-free human premolars with flat dentin surfaces were randomly divided into six groups of 10 teeth each and bonding was done using seventh-generation bonding agents Adper Easy One (3M ESPE) and Xeno V (Dentsply). Following the bonding procedure, resin composite was bonded to the surfaces using a plastic mould. The prepared specimen with composite cylinders attached were placed in 37°C distilled water for 24 h and then subjected to shear bond strength (SBS) with 0 h universal testing machine and the data were subjected to one-way analysis of variance and unpaired t-test. Results: Statistical significant difference between the Groups I, II and III in which Adper Easy One was used and similarly for Groups IV, V, and VI in which Xeno V was used. When an intergroup comparison was made using unpaired t-test Group II and Group V showed the nonsignificant difference. Conclusion: Salivary contamination significantly affects the SBS of both the seventh generation dentin bonding agents. However, 2-hydroxyethyl methacryate based adhesive has higher bond strength. PMID:26752841

  7. Effect of Er,Cr:YSGG Laser at Different Output Powers on the Micromorphology and the Bond Property of Non-Carious Sclerotic Dentin to Resin Composites

    PubMed Central

    Wang, Weiguo; Jiao, Yang; Wang, Wanshan; Yang, Yanwei; Wei, Jingjing; Shen, Lijuan; Chen, Jihua

    2015-01-01

    Background The objective of this study was to investigate the influence of Er,Cr:YSGG laser irradiated at different powers on the micromorphology and the bonding property of non-carious sclerotic dentin to resin composites. Methods Two hundred bovine incisors characterized by non-carious sclerotic dentin were selected, and the seventy-two teeth of which for surface morphological analysis were divided into nine groups according to various treatments (A: the control group, B: only treated with the adhesive Adper Easy One, C: diamond bur polishing followed by Adper Easy One, D-I: Er,Cr:YSGG laser irradiating at 1W, 2W, 3W, 4W, 5W, 6W output power, respectively, followed by Adper Easy One). The surface roughness values were measured by the non-contact three-dimensional morphology scanner, then the surface micromorphologies of surfaces in all groups were assessed by scanning electron microscopy (SEM); meanwhile, Image Pro-Plus 6.0 software was used to measure the relative percentage of open tubules on SEM images. The rest, one hundred twenty-eight teeth for bond strength test, were divided into eight groups according to the different treatments (A: only treated with the adhesive Adper Easy One, B: diamond bur polishing followed by the above adhesive, C-H: Er,Cr:YSGG laser irradiating at 1 W, 2 W, 3 W, 4 W, 5 W, 6 W output power, respectively, followed by the above adhesive), and each group was subsequently divided into two subgroups according to whether aging is performed (immediately tested and after thermocycling). Micro-shear bond strength test was used to evaluate the bond strength. Results The 4W laser group showed the highest roughness value (30.84±1.93μm), which was statistically higher than the control group and the diamond bur groups (p<0.05). The mean percentages ((27.8±1.8)%, (28.0±2.2)%, (30.0±1.9)%) of open tubules area in the 4W, 5W, 6W group were higher than other groups (p<0.05). The 4W laser group showed the highest micro-shear bond strength not

  8. Comparison of tensile bond strengths of four one-bottle self-etching adhesive systems with Er:YAG laser-irradiated dentin.

    PubMed

    Jiang, Qianzhou; Chen, Minle; Ding, Jiangfeng

    2013-12-01

    This study aimed to investigate the interaction of current one-bottle self-etching adhesives and Er:YAG laser with dentin using a tensile bond strength (TBS) test and scanning electron microscopy (SEM) in vitro. Two hundred and thirteen dentin discs were randomly distributed to the Control Group using bur cutting and to the Laser Group using an Er:YAG laser (200 mJ, VSP, 20 Hz). The following adhesives were investigated: one two-step total-etch adhesive [Prime & Bond NT (Dentsply)] and four one-step self-etch adhesives [G-Bond plus (GC), XENO V (Dentsply), iBond Self Etch (Heraeus) and Adper Easy One (3 M ESPE)]. Samples were restored with composite resin, and after 24-hour storage in distilled water, subjected to the TBS test. For morphological analysis, 12 dentin specimens were prepared for SEM. No significant differences were found between the control group and laser group (p = 0.899); dentin subjected to Prime & Bond NT, XENOV and Adper Easy One produced higher TBS. In conclusion, this study indicates that Er:YAG laser-prepared dentin can perform as well as bur on TBS, and some of the one-step one-bottle adhesives are comparable to the total-etch adhesives in TBS on dentin.

  9. Comparison of shear bond strengths of orthodontic brackets bonded with flowable composites.

    PubMed

    Turgut, Melek D; Attar, Nuray; Korkmaz, Yonca; Gokcelik, Aylin

    2011-01-01

    This study evaluated the shear bond strengths of orthodontic brackets bonded to human premolars using five different combinations of flowable composites and one-step self-etching adhesives (n=12): (1) Adper Easy Bond+Filtek Supreme XT Flow; (2) Futurabond NR+Grandio Flow; (3) Clearfil S3 Bond+Clearfil Majesty Flow; (4) AdheSE One+Tetric EvoFlow; and (5) Transbond Plus Self Etching Primer+Transbond XT Light Cure Adhesive. After shear bond strength testing, adhesive remnant index (ARI) scores were given according to the amount of adhesive and resin remaining on the brackets. On shear bond strength, there were no statistically significant differences between Groups 2 and 4 and between Groups 3 and 5 (p>0.05). On ARI scores, the predominant ARI scores in Groups 1, 2, 3, and 5 were 4, 2, 5, and 4 respectively; in Group 4, they were 0 and 4. Results showed that some combinations of flowable composites and self-etching adhesives might not be suitable for orthodontic use due to their low shear bond strengths and high ARI scores -with the latter signaling the risk of damaging the enamel surface during debonding. PMID:21282886

  10. Bonding stability of adhesive systems to eroded dentin.

    PubMed

    Cruz, Janaina Barros; Bonini, Gabriela; Lenzi, Tathiane Larissa; Imparato, José Carlos Pettorossi; Raggio, Daniela Prócida

    2015-01-01

    This in vitro study evaluated the immediate and 6 months microshear bond strength (µSBS) of different adhesive systems to sound and eroded dentin. Sixty bovine incisors were embedded in acrylic resin and ground to obtain flat buccal dentin surfaces. Specimens were randomly allocated into two groups: sound dentin (immersion in artificial saliva) and eroded dentin (erosive challenge following a pH cycling model comprising 4 ×/day Sprite Light® drink for 10 days). Then, specimens were reassigned according to the adhesive system: etch-and-rinse adhesive (Adper Single Bond), two-step self-etch system (Clearfil SE Bond), or one-step self-etch adhesive (Adper Easy One). Polyethylene tubes with an internal diameter of 0.76 mm were placed over pre-treated dentin and filled with resin composite (Z250). Half of the specimens were evaluated by the µSBS test after 24 h, and the other half 6 months later, after water storage at 37 °C. Failure mode was evaluated using a stereomicroscope (400 ×). Data were analyzed by three-way repeated measures analysis of variance and Tukey's post hoc tests (α = 0.05). After 6 months of water aging, marked reductions in µSBS values were observed, irrespective of the substrate. The µSBS values for eroded dentin were lower than those obtained for sound dentin. No difference in bonding effectiveness was observed among adhesive systems. For all groups, adhesive/mixed failure was observed. In conclusion, eroded dentin compromises the bonding quality of adhesive systems over time. PMID:26154377

  11. First-order superfluid to valence-bond solid phase transitions in easy-plane SU (N ) magnets for small N

    NASA Astrophysics Data System (ADS)

    D'Emidio, Jonathan; Kaul, Ribhu K.

    2016-02-01

    We consider the easy-plane limit of bipartite SU (N ) Heisenberg Hamiltonians, which have a fundamental representation on one sublattice and the conjugate to fundamental on the other sublattice. For N =2 the easy plane limit of the SU(2) Heisenberg model is the well-known quantum X Y model of a lattice superfluid. We introduce a logical method to generalize the quantum X Y model to arbitrary N , which keeps the Hamiltonian sign-free. We show that these quantum Hamiltonians have a world-line representation as the statistical mechanics of certain tightly packed loop models of N colors in which neighboring loops are disallowed from having the same color. In this loop representation we design an efficient Monte Carlo cluster algorithm for our model. We present extensive numerical results for these models on the two dimensional square lattice, where we find the nearest neighbor model has superfluid order for N ≤5 and valence-bond order for N >5 . By introducing SU (N ) easy-plane symmetric four-spin couplings we are able to tune across the superfluid-VBS phase boundary for all N ≤5 . We present clear evidence that this quantum phase transition is first order for N =2 and N =5 , suggesting that easy-plane deconfined criticality runs away generically to a first-order transition for small N .

  12. Effect of thermal aging on the tensile bond strength at reduced areas of seven current adhesives.

    PubMed

    Baracco, Bruno; Fuentes, M Victoria; Garrido, Miguel A; González-López, Santiago; Ceballos, Laura

    2013-07-01

    The purpose of this study was to determine the micro-tensile bond strength (MTBS) to dentin of seven adhesive systems (total and self-etch adhesives) after 24 h and 5,000 thermocycles. Dentin surfaces of human third molars were exposed and bonded with two total-etch adhesives (Adper Scotchbond 1 XT and XP Bond), two two-step self-etch adhesives (Adper Scotchbond SE and Filtek Silorane Adhesive System) and three one-step self-etch adhesives (G-Bond, Xeno V and Bond Force). All adhesive systems were applied following manufacturers' instructions. Composite buildups were constructed and the bonded teeth were then stored in water (24 h, 37 °C) or thermocycled (5,000 cycles) before being sectioned and submitted to MTBS test. Two-way ANOVA and subsequent comparison tests were applied at α = 0.05. Characteristic de-bonded specimens were analyzed using scanning electron microscopy (SEM). After 24 h water storage, MTBS values were highest with XP Bond, Adper Scotchbond 1 XT, Filtek Silorane Adhesive System and Adper Scotchbond SE and lowest with the one-step self-etch adhesives Bond Force, Xeno V and G-Bond. After thermocycling, MTBS values were highest with XP Bond, followed by Filtek Silorane Adhesive System, Adper Scotchbond SE and Adper Scotchbond 1 XT and lowest with the one-step self-etch adhesives Bond Force, Xeno V and G-Bond. Thermal aging induced a significant decrease in MTBS values with all adhesives tested. The resistance of resin-dentin bonds to thermal-aging degradation was material dependent. One-step self-etch adhesives obtained the lowest MTBS results after both aging treatments, and their adhesive capacity was significantly reduced after thermocycling.

  13. Effect of thermal aging on the tensile bond strength at reduced areas of seven current adhesives.

    PubMed

    Baracco, Bruno; Fuentes, M Victoria; Garrido, Miguel A; González-López, Santiago; Ceballos, Laura

    2013-07-01

    The purpose of this study was to determine the micro-tensile bond strength (MTBS) to dentin of seven adhesive systems (total and self-etch adhesives) after 24 h and 5,000 thermocycles. Dentin surfaces of human third molars were exposed and bonded with two total-etch adhesives (Adper Scotchbond 1 XT and XP Bond), two two-step self-etch adhesives (Adper Scotchbond SE and Filtek Silorane Adhesive System) and three one-step self-etch adhesives (G-Bond, Xeno V and Bond Force). All adhesive systems were applied following manufacturers' instructions. Composite buildups were constructed and the bonded teeth were then stored in water (24 h, 37 °C) or thermocycled (5,000 cycles) before being sectioned and submitted to MTBS test. Two-way ANOVA and subsequent comparison tests were applied at α = 0.05. Characteristic de-bonded specimens were analyzed using scanning electron microscopy (SEM). After 24 h water storage, MTBS values were highest with XP Bond, Adper Scotchbond 1 XT, Filtek Silorane Adhesive System and Adper Scotchbond SE and lowest with the one-step self-etch adhesives Bond Force, Xeno V and G-Bond. After thermocycling, MTBS values were highest with XP Bond, followed by Filtek Silorane Adhesive System, Adper Scotchbond SE and Adper Scotchbond 1 XT and lowest with the one-step self-etch adhesives Bond Force, Xeno V and G-Bond. Thermal aging induced a significant decrease in MTBS values with all adhesives tested. The resistance of resin-dentin bonds to thermal-aging degradation was material dependent. One-step self-etch adhesives obtained the lowest MTBS results after both aging treatments, and their adhesive capacity was significantly reduced after thermocycling. PMID:22790477

  14. Eroded dentin does not jeopardize the bond strength of adhesive restorative materials.

    PubMed

    Cruz, Janaina Barros; Lenzi, Tathiane Larissa; Tedesco, Tamara Kerber; Guglielmi, Camila de Almeida Brandão; Raggio, Daniela Prócida

    2012-01-01

    This in vitro study evaluated the bond strength of adhesive restorative materials to sound and eroded dentin. Thirty-six bovine incisors were embedded in acrylic resin and ground to obtain flat buccal dentin surfaces. Specimens were randomly allocated in 2 groups: sound dentin (immersion in artificial saliva) and eroded dentin (pH cycling model - 3× / cola drink for 7 days). Specimens were then reassigned according to restorative material: glass ionomer cement (KetacTM Molar Easy Mix), resin-modified glass ionomer cement (VitremerTM) or adhesive system with resin composite (Adper Single Bond 2 + Filtek Z250). Polyethylene tubes with an internal diameter of 0.76 mm were placed over the dentin and filled with the material. The microshear bond test was performed after 24 h of water storage at 37ºC. The failure mode was evaluated using a stereomicroscope (400×). Bond strength data were analyzed with two-way ANOVA and Tukey's post hoc tests (α = 0.05). Eroded dentin showed bond strength values similar to those for sound dentin for all materials. The adhesive system showed the highest bond strength values, regardless of the substrate (p < 0.0001). For all groups, the adhesive/mixed failure prevailed. In conclusion, adhesive materials may be used in eroded dentin without jeopardizing the bonding quality. It is preferable to use an etch-and-rinse adhesive system because it shows the highest bond strength values compared with the glass ionomer cements tested. PMID:22714927

  15. Effect of Thermocycling, Degree of Conversion, and Cavity Configuration on the Bonding Effectiveness of All-in-One Adhesives.

    PubMed

    El-Damanhoury, H M; Gaintantzopoulou, M

    2015-01-01

    The aim of this study was to compare five all-in-one bonding agents with respect to microleakage, microtensile bond strength (μTBS), degree of conversion (DC) and the impact of cavity configuration. The materials tested were Adper Easy Bond, Clearfil S3 Bond, iBond, Optibond All-in-One, Xeno IV, and Adper Single Bond Plus as a control. The DC of each adhesive was measured on the surfaces of dentin discs (n=5) by attenuated total reflectance Fourier transform infrared spectroscopy. One hundred and forty-four extracted human molars were randomly divided and assigned to one of the five tested adhesives and the control group. The μTBS to dentin was measured on flat occlusal dentin with and without thermocycling and to the gingival floor dentin of class II cavities (n=8). All specimens were restored with Filtek Z250 resin composite. Class II samples were immersed in a 5% methylene blue dye solution for 24 hours, and microleakage was examined under a stereomicroscope. Micromorphological analysis of demineralized/deproteinized specimens was done using scanning electron microscopy. The DC and microleakage data were statistically analyzed by one-way analysis of variance (ANOVA) and μTBS data by two-way ANOVA followed by a Bonferroni multiple comparison post hoc test (α=0.05) and Weibull-distribution survival analysis. The relation between different variables and μTBS and microleakage was tested by the Pearson correlation coefficient and regression statistics. A moderate direct relation between DC and μTBS durability was found for all the adhesives tested. Significant wide variations exist among the results obtained for single-bottle adhesives tested regarding their μTBS and microleakage. Some of the all-in-one materials tested have shown significantly inferior results under a high C-factor or after aging. The use of these materials should be carefully considered. PMID:25748210

  16. The Effect of Different Disinfecting Agents on Bond Strength of Resin Composites

    PubMed Central

    Mohammed Hassan, Ahmed; Ali Goda, Ahmed; Baroudi, Kusai

    2014-01-01

    Objective. The aim of this study was to evaluate the effect of different disinfectant agents on bond strength of two types of resin composite materials. Methods. A total of 80 sound posterior teeth were used. They were divided into four groups (n = 20) according to the dentin surface pretreatment (no treatment, chlorhexidine gluconate 2%, sodium hypochlorite 4%, and EDTA 19%). Each group was divided into two subgroups according to the type of adhesive (prime and bond 2.1 and Adper easy one). Each subgroup was further divided into two subgroups according to the type of resin composite (TPH spectrum and Tetric EvoCeram). Shear bond strength between dentin and resin composite was measured using Universal Testing Machine. Data collected were statistically analyzed by t-test and one-way ANOVA followed by Tukey's post hoc test. Results. It was found that dentin treated with EDTA recorded the highest shear bond strength values followed by sodium hypochlorite and then chlorhexidine groups while the control group showed the lowest shear bond strength. Conclusions. The surface treatment of dentin before bonding application has a great effect on shear bond strength between resin composite and dentin surface. PMID:25477961

  17. The effect of different disinfecting agents on bond strength of resin composites.

    PubMed

    Mohammed Hassan, Ahmed; Ali Goda, Ahmed; Baroudi, Kusai

    2014-01-01

    Objective. The aim of this study was to evaluate the effect of different disinfectant agents on bond strength of two types of resin composite materials. Methods. A total of 80 sound posterior teeth were used. They were divided into four groups (n = 20) according to the dentin surface pretreatment (no treatment, chlorhexidine gluconate 2%, sodium hypochlorite 4%, and EDTA 19%). Each group was divided into two subgroups according to the type of adhesive (prime and bond 2.1 and Adper easy one). Each subgroup was further divided into two subgroups according to the type of resin composite (TPH spectrum and Tetric EvoCeram). Shear bond strength between dentin and resin composite was measured using Universal Testing Machine. Data collected were statistically analyzed by t-test and one-way ANOVA followed by Tukey's post hoc test. Results. It was found that dentin treated with EDTA recorded the highest shear bond strength values followed by sodium hypochlorite and then chlorhexidine groups while the control group showed the lowest shear bond strength. Conclusions. The surface treatment of dentin before bonding application has a great effect on shear bond strength between resin composite and dentin surface. PMID:25477961

  18. Influence of Organic Acids from the Oral Biofilm on the Bond Strength of Self-Etch Adhesives to Dentin.

    PubMed

    Amaral, Cristiane Mariote; Correa, Danielly de Sá; Miragaya, Luciana Meirelles; Silva, Eduardo Moreira da

    2015-10-01

    The aim of this study was to evaluate the microtensile bond strength of self-etch adhesive systems to dentin after storage in acids from oral biofilm. Three adhesive systems were used in the study: a two-step self-etch adhesive for use with a silorane-based resin composite (Filtek P90 adhesive system - P90), a two-step self-etch adhesive (Clearfil SE Bond - CSE) and a one-step self-etch adhesive (Adper Easy One - AEO). The bond strength of these products was evaluated by bonding resin composite (Filtek Z350 for CSE and AEO; and Filtek P90 for P90) to 90 bovine dentin tooth fragments, according to the manufacturer's instructions. After 24 h of water storage at 37 °C, the specimens were sectioned into beams (1 mm2) divided and stored in distilled water, lactic acid and propionic acid, for 7 and 30 days. After storage, the specimens were tested for microtensile bond strength. Data were analyzed by three-way ANOVA and Tukey´s test (α=0.05). CSE presented the highest microtensile bond strength after storage in distilled water for 7 and 30 days. The microtensile bond strength of all adhesive systems was lower after storage in lactic acid and propionic acid than after water storage. Significant difference was not found between storage times. PMID:26647935

  19. Easy Meal

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The woman pictured below is sitting down to a nutritious, easily-prepared meal similar to those consumed by Apollo astronauts. The appetizing dishes shown were created simply by adding water to the contents of a Mountain House* Easy Meal package of freeze dried food. The Easy Meal line is produced by Oregon Freeze Dry Foods, Inc., Albany, Oreaon, a pioneer in freeze drying technology and a company long associated with NASA in developing suitable preparations for use on manned spacecraft. Designed to provide nutritionally balanced, attractive hot meals for senior adults, Easy Meal is an offshoot of a 1975-77 demonstration project managed by Johnson Space Center and called Meal System for the Elderly. The project sought ways to help the estimated 3.5 million elderly Americans who are unable to take advantage of existing meal programs. Such services are provided by federal, state and local agencies, but they are not available to many who live in rural areas, or others who are handicapped, temporarily ill or homebound for other reasons. Oregon Freeze Dry Foods was a participant in that multi-agency cooperative project. With its Easy Meal assortment of convenience foods pictured above left, the company is making commercially available meal packages similar to those distributed in the Meal System for the Elderly program. In the freeze drying process, water is extracted from freshly-cooked foods by dehydration at very low temperatures, as low as 50 I degrees below zero. Flavor is locked in by packaging the dried food in pouches which block out moisture and oxygen, the principal causes of food deterioration; thus the food can be stored for long periods without refrigeration. Meals are reconstituted by adding hot or cold water, depending on the type of food, and they are table ready in five to 10 minutes. Oregon Freeze Dry Foods offers five different meal packages and plans to expand the line.

  20. Micro-tensile bond strength of different adhesive systems on sound dentin and resin-based composite: An in-vitro study

    PubMed Central

    Mallick, Rashmirekha; Sarangi, Priyanka; Mohanty, Sandhyarani; Behera, Subasish; Nanda, Soumyaranjan; Satapathy, Sukanta Kumar

    2015-01-01

    Aim: To analyze the difference in the micro-tensile bond strength of specimens made with two different adhesive systems and compare them with two homogenous substrates. Materials and Methods: Sixty permanent mandibular molars were mounted in acrylic blocks and sectioned with exposed dentin surfaces. Samples were then divided into four groups. To Group-I Adper Single Bond 2 and to Group-II Adper Self-Etch plus bonding agents were applied. For Group-I and Group-II beams consisted of resin composite in the upper half and dentin in the lower half. In Group-III beams were made of only dentin. In Group-IV beams were made of only composite. Fifteen specimens of each group were taken for the micro-tensile bond strength test. Statistical Analysis: The results are analyzed using one-way analysis of variance and Critical Difference test. Results: The interface bonded with the two adhesive systems had lower micro-tensile bond strength than those of dentin and resin composite and the self-etching adhesive Adper Self-Etch plus had comparable bond strength with total-etch adhesive Adper Single Bond 2. Conclusion: The bond strength values for current adhesive systems cannot be compared to the micro-tensile bond strength of dentin and resin composite, and self-etching adhesives have comparable bond strength with total-etch adhesives. PMID:26430301

  1. The effect of cavity disinfectants on the micro-shear bond strength of dentin adhesives

    PubMed Central

    Elkassas, Dina Wafik; Fawzi, Elham Mostafa; El Zohairy, Ahmed

    2014-01-01

    Objectives: This study was carried out to examine the effect of application of four different disinfecting agents on the micro-shear bond strength (μ-SBS) of an etch-and-rinse and self-etch adhesive systems. Materials and Methods: One hundred flat dentin surfaces of human molars were produced by wet grinding the buccal surfaces. Specimens were randomly assigned to five groups according to the disinfectant used: Group I: Control (no disinfectant); Group II: 5.25% sodium hypochlorite based; Group III: 2% chlorhexidine based (Consepsis), Group IV: 0.1% benzalkoniumchloride based (Tubulicid red) and Group V: 3% doxycycline based (Biopure, MTAD). Specimens were bonded using either Adper Single Bond 2 or Clearfil S3 Bond, which were employed according to the manufacturer's instructions. Resin composite microcylinders were bonded using Tygon® tubes for μ-SBS testing. The modes of failure were noted after visual examination using a binocular stereomicroscope at ×25 magnification. Failures were classified as adhesive, or mixed. μ-SBS results were analyzed using two-way ANOVA followed by Tukey's post-hoc test. Results: Dentin disinfectants tested significantly negated the bonding of Adper Single bond 2 and the groups were ranked; Group I > Group V = Group IV > Group II = Group III, meanwhile they enhanced significantly the μ-SBS values upon using Clearfil S3 Bond and were ranked; Group II > Group III = Group IV = Group V > Group I. Most failures were adhesive with the Adper single bond adhesive system. Mixed modes of failure were evident with Clearfil S3 bond. Conclusions: The disinfectants tested should not be used with Adper Single Bond 2 when applied before the etching step, However they could be used safely prior to bonding with Clearfil S3 Bond. PMID:24966768

  2. Easy oxidative addition of the carbon-halogen bond by dimethylplatinum(II) complexes containing a related series of diimine ligands: Synthesis, spectral characterization and crystal structure

    NASA Astrophysics Data System (ADS)

    Momeni, Badri Z.; Fathi, Nastaran; Mohagheghi, Arezoo

    2015-01-01

    Dimethylplatinum(II) complexes [PtMe2(NN)] {NN = 4,4‧-Me2bpy (4,4‧-dimethyl-2,2‧-bipyridine); 5,5‧-Me2bpy (5,5‧-dimethyl-2,2‧-bipyridine)} were reacted with alkyl halides (RX = EtI, EtBr) to yield the organoplatinum(IV) complexes [PtMe2RX(NN)]. On the basis of NMR data, the platinum(IV) product of each reaction contains almost exclusively the trans isomer but small traces of the cis isomers are also observed. On the other hand, the reaction of [PtMe2(NN)] {NN = bu2bpy (4,4‧-di-tert-butyl-2,2‧-bipyridine); 4,4‧-Me2bpy; 5,5‧-Me2bpy} with CH2Br2 gave a mixture of cis and trans-[PtMe2(CH2Br)Br(NN)] formed by the oxidative addition of one of the C-Br bonds. The formation of the cis isomer increases in the order of 5,5‧-Me2bpy > bu2bpy > 4,4‧-Me2bpy. The reaction of [PtMe2(NN)] {NN = bpy (2,2‧-bipyridine), phen (1,10-phenanthroline)} with 1,8-dibromooctane or 1,9-dibromononane afforded the mononuclear complexes [PtMe2{(CH2)nBr}Br(NN)] (n = 8-9). The products were fully characterized by elemental analysis, 1H, 13C, HH COSY, HMQC, DEPT and DEPTQ-135 NMR spectroscopy. The crystal structure of [PtMe2EtI(4,4‧-Me2bpy)] reveals that Pt(IV) atom is six-coordinated in a slightly distorted octahedral geometry with the ethyl group trans to iodide.

  3. Analysis of micro-shear bond strength of self-etch adhesive systems with dentine: An in vitro study

    PubMed Central

    Shakya, Vijay Kumar; Singh, Rajeev Kumar; Pathak, Anjani Kumar; Singh, Balendra Pratap; Chandra, Anil; Bharti, Ramesh; Yadav, Rakesh Kumar

    2015-01-01

    Background Success or failure of a composite restoration largely depends on its bonding to enamel/dentine. Several better adhesive systems have been developed during the last few years due to rapid advancement in the technology. Recent self-etched adhesives have fewer clinical steps and are less technique sensitive. Methods Ninety extracted human permanent molars were collected, grounded and finished to prepare flat dentine-bonding surfaces on their occlusal surface. All specimens were divided into three groups (n = 30) on the basis of three adhesive systems Adper Easy Bond (AE), Beautibond (BB) and Xeno IV (XE). These adhesive systems were applied on prepared mid-dentine-bonding surface. A restorative resin was added with the help of a transparent tube of 2 mm height and 1.7 mm internal diameter and cured. Fifteen specimens in each group were loaded to failure in an Instron Universal Testing Machine after storage for 24 h at 37 °C to check micro-shear bond strength. Another fifteen specimens from each group were thermocycled 500 times at 5 °C and 55 °C with dwell time of 1 min in each bath followed by loading to failure. The data obtained was analyzed with SPSS version 21 at significance level of <05. Results After 24 h, micro-shear bond strength of BB was higher (26.04 MPa) than XE (23.69 MPa) and AE (21.50 MPa). After thermocycling, micro-shear bond strength decreased significantly in BB (P = .001) and XE (P = .03). Conclusion The micro-shear bond strength of BB was highest among three groups, which decreased after thermocycling. PMID:26605144

  4. Effects of endodontic tri-antibiotic paste on bond strengths of dentin adhesives to coronal dentin

    PubMed Central

    Mirzakoucheki, Parvin; Walter, Ricardo; Jahromi, Maryam Zare; Mirsattari, Sanaz; Akbarzadeh, Navid

    2015-01-01

    Objectives The aim of this study was to evaluate the effects of tri-antibiotic paste (TAP) on microtensile bond strengths (MTBS) of dental adhesives to dentin. Materials and Methods Sixty extracted molars had their occlusal surfaces flattened to expose dentin. They were divided into two groups, i.e., control group with no dentin treatment and experimental group with dentin treatment with TAP. After 10 days, specimens were bonded using self-etch (Filtek P90 adhesive) or etch-and-rinse (Adper Single Bond Plus) adhesives and restored with composite resin. Teeth were sectioned into beams, and the specimens were subjected to MTBS test. Data were analyzed using two-way ANOVA and post hoc Tukey tests. Results There was a statistically significant interaction between dentin treatment and adhesive on MTBS to coronal dentin (p = 0.003). Despite a trend towards worse MTBS being noticed in the experimental groups, TAP application showed no significant effect on MTBS (p = 0.064). Conclusions The etch-and-rinse adhesive Adper Single Bond Plus presented higher mean bond strengths than the self-etch adhesive Filtek P90, irrespective of the group. The superior bond performance for Adper Single Bond when compared to Filtek P90 adhesive was confirmed by a fewer number of adhesive failures. The influence of TAP in bond strength is insignificant. PMID:25984475

  5. Does bonding to dentin reduce microleakage of composite restorations?

    PubMed

    Faria-e-silva, André L; Soares, Paulo V; Baroni, Daniela B; Menezes, Murilo S; Santos-Filho, Paulo C F; Soares, Carlos J; Aguiar, Flávio H B; Martins, Luís R M

    2012-01-01

    This study evaluated the effect of adhesive application only to enamel on the marginal microleakage of composite resin restorations performed with different adhesive systems. Standardized cylinder-shaped cavities were prepared on the buccal surface of eighty bovine incisors. Two etch-and-rinse (Adper Scotchbond Multi-purpose [3M ESPE, St. Paul, MN USA] and Adper Single Bond 2 [3M ESPE]) and two self-etching (Clearfil SE Bond [Kuraray, Osaka, Japan] and Adper Prompt [3M ESPE]) adhesive systems were evaluated. The adhesives were applied only to enamel or to both dentin and enamel. After adhesive light-activation, the cavities were restored with composite resin. The samples were coated with two layers of nail polish, except an area of 1-mm wide around of the restoration, and immersed in a methylene blue solution. Afterwards, the specimens were ground in order to obtain powder which was immersed in absolute alcohol. The solutions were centrifuged and the supernatant was analyzed using an absorbance spectrophotometer. Linear regression was used to estimate the dye concentration. Data were analyzed using ANOVA and Tukey's tests (alpha = 0.05). The etch-and-rinse adhesives showed lower microleakage means compared to those of the self-etching adhesives. Adper Prompt presented higher microleakage means. There was no difference between the modes of application of the adhesive on the cavity for all adhesive systems, except for Clearfil SE Bond. This showed lower microleakage when applied to the whole cavity. Bonding to dentin may not reduce microleakage of composite restorations. PMID:22928376

  6. INFLUENCE OF DIFFERENT ADHESIVE SYSTEMS ON THE PULL-OUT BOND STRENGTH OF GLASS FIBER POSTS

    PubMed Central

    da Silva, Luciana Mendonça; de Andrade, Andréa Mello; Machuca, Melissa Fernanda Garcia; da Silva, Paulo Maurício Batista; da Silva, Ricardo Virgolino C.; Veronezi, Maria Cecília

    2008-01-01

    This in vitro study evaluated the tensile bond strength of glass fiber posts (Reforpost – Angelus-Brazil) cemented to root dentin with a resin cement (RelyX ARC – 3M/ESPE) associated with two different adhesive systems (Adper Single Bond - 3M/ESPE and Adper Scotchbond Multi Purpose (MP) Plus – 3M/ESPE), using the pull-out test. Twenty single-rooted human teeth with standardized root canals were randomly assigned to 2 groups (n=10): G1- etching with 37% phosphoric acid gel (3M/ESPE) + Adper Single Bond + #1 post (Reforpost – Angelus) + four #1 accessory posts (Reforpin – Angelus) + resin cement; G2- etching with 37% phosphoric acid gel + Adper Scotchbond MP Plus + #1 post + four #1 accessory posts + resin cement. The specimens were stored in distilled water at 37°C for 7 days and submitted to the pull-out test in a universal testing machine (EMIC) at a crosshead speed of 0.5 mm/min. The mean values of bond strength (kgf) and standard deviation were: G1- 29.163 ± 7.123; G2- 37.752 ±13.054. Statistical analysis (Student's t-test; α=0.05 showed no statistically significant difference (p<0.05) between the groups. Adhesive bonding failures between resin cement and root canal dentin surface were observed in both groups, with non-polymerized resin cement in the apical portion of the post space when Single Bond was used (G1). The type of adhesive system employed on the fiber post cementation did not influence the pull-out bond strength. PMID:19089224

  7. Comparative study of the dentin bond strength of a new universal adhesive.

    PubMed

    Jang, Ji-Hyun; Lee, Myoung Geun; Woo, Sang Uk; Lee, Chung Ok; Yi, Jin-Kyu; Kim, Duck-Su

    2016-01-01

    This study compared the dentin bond strength of a new universal adhesive with that of contemporary multi-step dentin adhesives. Six experimental groups were prepared according to the adhesives used and their application modes: Optibond FL (OB), Adper Single Bond Plus (SB), One-Step Plus (OS), Clearfil SE Bond (CS), All-Bond Universal using etch-and-rinse mode (ABE), and AllBond Universal using self-etch mode (ABS). Micro-tensile bond strength (µTBS) and failure mode were evaluated for each group. The bonded interface was analyzed using transmission electron microscopy (TEM). As a result, µTBS of 6 experimental groups was followed as: OB=ABE=SE=ABS>SB>OS group. TEM micrographs of ABE and ABS groups revealed a homogenous adhesive layer formation. In conclusion, a new universal adhesive can make reliable bond to dentin, regardless of the application mode. PMID:27477226

  8. A microtensile bond strength evaluation of a single-bottle adhesive to caries-affected dentin in conventional versus minimal invasive caries removal techniques: An in-vitro study

    PubMed Central

    Naik, Saraswathi V; Shashikiran, N D; Chaitra, N L; Syed, Ghousia

    2014-01-01

    Background and Objective: The current dental restorative concepts are characterized by an increased effort towards a less invasive treatment of carious lesions. Minimally invasive cavity preparation techniques are intended to preserve as much sound enamel and dentin as possible, during the treatment of carious lesions. The objective of this in vitro study is to evaluate the microtensile bond strength of single-etch adhesives (Adper Easy one) on caries-affected dentin, following three different caries removal techniques, namely, Carisolv, Conventional carbide bur at slow speed, and aqueous calcium hydroxide. Materials and Methods: A total of 30 teeth were divided into three groups and arranged with 10 samples in each group - round bur (Group A), Carisolv (Group B), Aqueous calcium hydroxide (Group C). Following caries excavation by using the three above -mentioned techniques, application of the bonding agent and composite buildup was done. Following sectioning of the samples with the help of a hard tissue microtome, Group A, B, and C were again trimmed into an hour-glass shape, maintaining a width of 1.2 mm in the center of an hour glass. These were debonded under a microtensile load at failure, using the Instron Universal Testing Machine. Results: There was a significantly lower microtensile bond strength in the group where the caries was removed by the round bur, as compared to the group where the caries was removed by using Carisolv and calcium hydroxide, which showed higher microtensile bond strength, that is, the significant pairing of Groups were Group A to Group B and Group A to Group C, exhibiting statistically significant difference with a P < 0.001. However, there was no statistically significant difference between Group B and Group C. Interpretation and Conclusion: Carisolv and aqueous calcium hydroxide have proven to be good methods of caries removal for achieving a higher microtensile bond strength of the single-bottle self-etch adhesive on dentin. PMID

  9. Effect of thermocycling on the durability of etch-and-rinse and self-etch adhesives on dentin.

    PubMed

    Sangwichit, Ketkamon; Kingkaew, Ruksaphon; Pongprueksa, Pong; Senawongse, Pisol

    2016-01-01

    The objective was to compare bond strengths of adhesives with/without thermocycling and to analyze the micromorphology of resindentin interfaces. Flat dentin surfaces were prepared and divided into eight groups to bond with four etch-and-rinse adhesives (Optibond FL, Adper Scotchbond Multi-Purpose, Optibond Solo Plus, and Single Bond 2) and four self-etch adhesives (Clearfil SE Bond, Adper SE Plus, Clearfil S(3) Bond and Adper Easy Bond). Specimens were further divided into two subgroups subjected for with/without thermocycling and then subjected to both micro-tensile test and resin-dentin interface evaluation. The results revealed that there were significant differences in bond strength between the groups with and without thermocycling for all etch-and-rinse groups and for the Adper Easy Bond self-etch group (p<0.01). Clearfil SE Bond demonstrated highly durable bond strengths. Furthermore, more silver ion uptake was observed at the resin-dentin interfaces for all etch-and-rinse adhesives and Adper SE Plus and Adper Easy Bond after thermocycling. PMID:27251990

  10. Effect of silorane-based adhesive system on bond strength between composite and dentin substrate

    PubMed Central

    Pereira, Jefferson Ricardo; Júnior, Lindomar Corrêa; de Souza Almeida, Mauro; do Valle, Accácio Lins; Honório, Heitor Marques; Vidotti, Hugo Alberto; De Souza, Grace Mendonca

    2015-01-01

    Context: The complexities of the oral environment, the dentin substrate, and the different bond and composite resin systems represent a challenge to the maintenance of reasonable bond between the composite resin and the tooth structure. Aims: To evaluate the effect of the adhesive system on bond strength between silorane-based composite resin and dentin. Materials and Methods: Fourteen human molars extracted were selected and vertically cut into 3 dentin fragments, randomly divided among the experimental groups and restored with Z250 and P90 composite resin using different adhesive protocols (Adper Single Bond 2, Silorano primer, Adper SE Plus, and Scotchbond Multiuse). Two composite resin cylinders were built up on each dentin surface (n = 10) and subjected to a micro-shear bond strength test. Statistical Analysis Used: Kruskal–Wallis one-way analysis of variance and Tukey test (P = 0.05). Results: According to the results, Kruskal–Wallis test evidenced at least one statistical significant difference (P = 0.001). The Tukey test showed statistically significant differences among the group (P < 0.05). Group PSM8 (P90 + SM) showed statically significant higher results when compared with groups PSP4 (P90 + SP), PSB2 (P90 + SB), and ZSE5 (Z250 + SE). Conclusion: The results evidenced that the monomer of the adhesive system has an effect on bond strength between the composite resin and dentin. PMID:26752846

  11. Shear bond strength of seventh generation bonding agents on dentin of primary teeth--an in vitro study.

    PubMed

    Gonzalez, Geoffrey; Rich, Alfred P; Finkelman, Matthew D; Defuria, Catherine

    2012-01-01

    This controlled, randomized, in vitro study evaluated the shear bond strength of several seventh generation bonding agents on the dentin of primary teeth. Six different adhesives were used: Xeno IV, Clearfil S3 Bond, Adper Prompt-L-Pop, AdheSE One, Bond Force, and Optibond (control). Ninety primary teeth were prepared by wet grinding with a 320-grit silicon carbide paper on a polishing wheel running at 110 RPM. After 24 hours of storage in water, shear bond strengths of each group were determined. The mean shear bond strength of the tested adhesive systems to primary dentin was 12.27 MPa. One-way ANOVA testing showed a statistically significant difference between adhesive products (P < 0.001). Tukey HSD post hoc tests were used to assess which means were significantly different from one another. There was no statistically significant difference between the fifth generation adhesive system (Optibond) and the two seventh generation systems (Xeno IV and Bond Force), with Optibond exhibiting a lower mean shear bond strength compared to Bond Force. Within the limitations of this study, there is a significant difference between seventh generation bonding materials. Bond Force and Optibond appear to exhibit higher shear bond strengths than the other products.

  12. Shear bond strength of seventh generation bonding agents on dentin of primary teeth--an in vitro study.

    PubMed

    Gonzalez, Geoffrey; Rich, Alfred P; Finkelman, Matthew D; Defuria, Catherine

    2012-01-01

    This controlled, randomized, in vitro study evaluated the shear bond strength of several seventh generation bonding agents on the dentin of primary teeth. Six different adhesives were used: Xeno IV, Clearfil S3 Bond, Adper Prompt-L-Pop, AdheSE One, Bond Force, and Optibond (control). Ninety primary teeth were prepared by wet grinding with a 320-grit silicon carbide paper on a polishing wheel running at 110 RPM. After 24 hours of storage in water, shear bond strengths of each group were determined. The mean shear bond strength of the tested adhesive systems to primary dentin was 12.27 MPa. One-way ANOVA testing showed a statistically significant difference between adhesive products (P < 0.001). Tukey HSD post hoc tests were used to assess which means were significantly different from one another. There was no statistically significant difference between the fifth generation adhesive system (Optibond) and the two seventh generation systems (Xeno IV and Bond Force), with Optibond exhibiting a lower mean shear bond strength compared to Bond Force. Within the limitations of this study, there is a significant difference between seventh generation bonding materials. Bond Force and Optibond appear to exhibit higher shear bond strengths than the other products. PMID:22313979

  13. GFI - EASY PC GRAPHICS

    NASA Technical Reports Server (NTRS)

    Katz, R. B.

    1994-01-01

    Easy PC Graphics (GFI) is a graphical plot program that permits data to be easily and flexibly plotted. Data is input in a standard format which allows easy data entry and evaluation. Multiple dependent axes are also supported. The program may either be run in a stand alone mode or be embedded in the user's own software. Automatic scaling is built in for several logarithmic and decibel scales. New scales are easily incorporated into the code through the use of object-oriented programming techniques. For the autoscale routines and the actual plotting code, data is not retrieved directly from a file, but a "method" delivers the data, performing scaling as appropriate. Each object (variable) has state information which selects its own scaling. GFI is written in Turbo Pascal version 6.0 for IBM PC compatible computers running MS-DOS. The source code will only compile properly with the Turbo Pascal v. 6.0 or v. 7.0 compilers; however, an executable is provided on the distribution disk. This executable requires at least 64K of RAM and DOS 3.1 or higher, as well as an HP LaserJet printer to print output plots. The standard distribution medium for this program is one 5.25 inch 360K MS-DOS format diskette. The contents of the diskette are compressed using the PKWARE archiving tools. The utility to unarchive the files, PKUNZIP.EXE, is included. An electronic copy of the documentation is provided on the distribution medium in ASCII format. GFI was developed in 1993.

  14. Effect of enamel etching time on roughness and bond strength.

    PubMed

    Barkmeier, Wayne W; Erickson, Robert L; Kimmes, Nicole S; Latta, Mark A; Wilwerding, Terry M

    2009-01-01

    The current study examined the effect of different enamel conditioning times on surface roughness and bond strength using an etch-and-rinse system and four self-etch adhesives. Surface roughness (Ra) and composite to enamel shear bond strengths (SBS) were determined following the treatment of flat ground human enamel (4000 grit) with five adhesive systems: (1) Adper Single Bond Plus (SBP), (2) Adper Prompt L-Pop (PLP), (3) Clearfil SE Bond (CSE), (4) Clearfil S3 Bond (CS3) and (5) Xeno IV (X4), using recommended treatment times and an extended treatment time of 60 seconds (n = 10/group). Control groups were also included for Ra (4000 grit surface) and SBS (no enamel treatment and Adper Scotchbond Multi-Purpose Adhesive). For surface roughness measurements, the phosphoric acid conditioner of the SBP etch-and-rinse system was rinsed from the surface with an air-water spray, and the other four self-etch adhesive agents were removed with alternating rinses of water and acetone. A Proscan 2000 non-contact profilometer was used to determine Ra values. Composite (Z100) to enamel bond strengths (24 hours) were determined using Ultradent fixtures and they were debonded with a crosshead speed of 1 mm/minute. The data were analyzed with ANOVA and Fisher's LSD post-hoc test. The etch-and- rinse system (SBP) produced the highest Ra (microm) and SBS (MPa) using both the recommended treatment time (0.352 +/- 0.028 microm and 40.5 +/- 6.1 MPa) and the extended treatment time (0.733 +/- 0.122 microm and 44.2 +/- 8.2 MPa). The Ra and SBS of the etch-and-rinse system were significantly greater (p < 0.05) than all the self-etch systems and controls. Increasing the treatment time with phosphoric acid (SBP) and PLP produced greater surface roughness (p < 0.05) but did not result in significantly higher bond strengths (p > 0.05). PMID:19363978

  15. Easy Volcanic Aerosol

    NASA Astrophysics Data System (ADS)

    Toohey, Matthew; Stevens, Bjorn; Schmidt, Hauke; Timmreck, Claudia

    2016-04-01

    Radiative forcing by stratospheric sulfate aerosol of volcanic origin is one of the strongest drivers of natural climate variability. Transient model simulations attempting to match observed climate variability, such as the CMIP historical simulations, rely on volcanic forcing reconstructions based on observations of a small sample of recent eruptions and coarse proxy data for eruptions before the satellite era. Volcanic forcing data sets used in CMIP5 were provided either in terms of optical properties, or in terms of sulfate aerosol mass, leading to significant inter-model spread in the actual volcanic radiative forcing produced by models and in their resulting climate responses. It remains therefore unclear to what degree inter-model spread in response to volcanic forcing represents model differences or variations in the forcing. In order to isolate model differences, Easy Volcanic Aerosol (EVA) provides an analytic representation of volcanic stratospheric aerosol forcing, based on available observations and aerosol model results, prescribing the aerosol's radiative properties and primary modes of spatial and temporal variability. In contrast to regriddings of observational data, EVA allows for the production of physically consistent forcing for historic and hypothetical eruptions of varying magnitude, source latitude, and season. Within CMIP6, EVA will be used to reconstruct volcanic forcing over the past 2000 years for use in the Paleo-Modeling Intercomparison Project (PMIP), and will provide forcing sets for VolMIP experiments aiming to quantify model uncertainty in the response to volcanic forcing. Here, the functional form of EVA will be introduced, along with illustrative examples including the EVA-based reconstruction of volcanic forcing over the historical period, and that of the 1815 Tambora eruption.

  16. Effect of sodium ascorbate on the bond strength of all-in-one adhesive systems to NaOCl-treated dentin

    PubMed Central

    Ebrahimi-Chaharom, Mohammad-Esmaeel; Kimyai, Soodabeh; Mohammadi, Narmin; Oskoee, Parnian-Alizadeh; Daneshpuy, Mehdi

    2015-01-01

    Background Ascorbic acid and its salts are low-toxicity products, which are routinely used in food industries as antioxidants. The aim of the present study was to evaluate the effect of 10% sodium ascorbate on the bond strength of two all-in-one adhesive systems to NaOCl-treated dentin. Material and Methods After exposing the dentin on the facial surface of 90 sound human premolars and mounting in an acrylic resin mold, the exposed dentin surfaces were polished with 600-grit SiC paper under running water. Then the samples were randomly divided into 6 groups of 15. Groups 1 and 4 were the controls, in which no surface preparation was carried out. In groups 2 and 5 the dentin surfaces were treated with 5.25% NaOCl alone for 10 minutes and in groups 3 and 6 with 5.25% NaOCl for 10 minutes followed by 10% sodium ascorbate for 10 minutes. Then composite resin cylinders, measuring 2 mm in diameter and 2 mm in height, were bonded on the dentin surfaces in groups 1, 2 and 3 with Clearfil S3 Bond and in groups 4, 5 and 6 with Adper Easy One adhesive systems according to manufacturers’ instructions. The samples were stored in distilled water for 24 hours at 37°C and then thermocycled. Finally, the samples underwent shear bond strength test in a universal testing machine at a strain rate of 1 mm/min. Data were analyzed with two-way ANOVA and post hoc Tukey tests at α=0.05. Results The differences between groups 1 and 2 (P=0.01), 1 and 5 (P=0.003). 1 and 6 (P=0.03) and 4 and 5 (P=0.03) were statistically significant. Two-by-two comparisons did not reveal any significant difference between other groups (P>0.05). Conclusions Use of 10% sodium ascorbate for 10 minutes restored the decreased bond strength of the adhesive systems to that of the control groups. Key words:Sodium ascorbate, adhesive systems, all-in-one, bond strength, sodium hypochlorite. PMID:26644835

  17. Self-etching bonding systems: in-vitro shear bond strength evaluation.

    PubMed

    Brandt, P D; de Wet, F A; du Preez, I C

    2006-02-01

    The purpose of this in vitro study was to compare the dentine shear bond strength of five self-etching bonding agents with that of a total-etch dentine bonding agent (used as control). Sixty recently extracted third molar teeth were mounted in acrylic resin and the occlusal surfaces ground to expose superficial dentine. A standardised smear layer was created by polishing with wet 600-grit SiC paper. Products evaluated were Xeno III (XIII), Clearfil SE Bond (SE), ABF (ABF), Optibond Solo Self-etch (OS), Adper Prompt-L-Pop (PLP) and the control, Scotchbond Multipurpose Plus (SBMP). Resin stubs were bonded to the dentine using the bonding agents according to manufacturer's instructions. Composite stubs were manufactured using an Ultradent jig and two increments of Z100, A1 shade composite. The bonds were subsequently stressed to failure with an Instron testing machine, operating at a crosshead speed of 0.5 mm/min. The data was statistically analysed using ANOVA (alpha < or = 0.05). The mean SBS (MPa) were: SBMP (Control) = 24.1 +/- 7.6; XIII = 17.3 +/- 4.1; SE = 26.2 +/- 7.8; ABF = 25.9 +/- 4.3; OS = 21.9 +/- 3.9 and PLP = 15.4 +/- 3.1. The shear bond strengths of both XIII and PLP to dentine were significantly lower than the control SBMP (p < 0.05). The remaining three products (SE, ABF and OS) displayed bond strengths comparable to the control (p > 0.05). Further research into cut (ground) and un-cut (un-ground) enamel shear bond strength and micro-leakage using these bonding agents are needed. PMID:16562613

  18. ON THE DURABILITY OF RESIN-DENTIN BONDS: IDENTIFYING THE WEAKEST LINKS

    PubMed Central

    Zhang, Zihou; Beitzel, Dylan; Mutluay, Mustafa; Tay, Franklin R.; Pashley, David H.; Arola, Dwayne

    2015-01-01

    Fatigue of resin-dentin adhesive bonds is critical to the longevity of resin composite restorations. Objectives The objectives were to characterize the fatigue and fatigue crack growth resistance of resin-dentin bonds achieved using two different commercial adhesives and to identify apparent “weak-links”. Methods Bonded interface specimens were prepared using Adper Single Bond Plus (SB) or Adper Scotchbond Multi-Purpose (SBMP) adhesives and 3M Z100 resin composite according to the manufacturers instructions. The stress-life fatigue behavior was evaluated using the twin bonded interface approach and the fatigue crack growth resistance was examined using bonded interface Compact Tension (CT) specimens. Fatigue properties of the interfaces were compared to those of the resin-adhesive, resin composite and coronal dentin. Results The fatigue strength of the SBMP interface was significantly greater than that achieved by SB (p≤0.01). Both bonded interfaces exhibited significantly lower fatigue strength than that of the Z100 and dentin. Regarding the fatigue crack growth resistance, the stress intensity threshold (ΔKth) of the SB interface was significantly greater (p≤0.01) than that of the SBMP, whereas the ΔKth of the interfaces was more than twice that of the parent adhesives. Significance Collagen fibril reinforcement of the resin adhesive is essential to the fatigue crack growth resistance of resin-dentin bonds. Resin tags that are not well hybridized into the surrounding intertubular dentin and/or poor collagen integrity are detrimental to the bonded interface durability. PMID:26169318

  19. Regional bond strengths to root canal dentin of fiber posts luted with three cementation systems.

    PubMed

    Gomes, Giovana Mongruel; Gomes, Osnara Maria Mongruel; Reis, Alessandra; Gomes, João Carlos; Loguercio, Alessandro Dourado; Calixto, Abraham Lincoln

    2011-01-01

    This study evaluated the influence of the cementation system on the regional push-out bond strength and failure pattern of fiber posts to radicular dentin. The roots of 48 extracted human incisors were prepared and divided into 3 groups (n = 16), according to the cementation system: AdperScotchbond Multi-Purpose + resin cement RelyX ARC (SBMP+ARC); Adper SingleBond 2 + RelyX ARC (SB+ARC) and; RelyX U100 self-adhesive resin cement (U100). The posts were cemented as per manufacturer's instructions for each cementation system. After 1 week, the roots were sectioned transversely into 6 discs. Two discs were obtained from the cervical, middle and apical thirds and the push-out test was carried out. The failure pattern was examined on all debonded specimens. The data were analyzed by two-way repeated measures ANOVA and Tukey's test. When U100 was used, no statistically significant difference (p>0.05) was observed among the different root regions. Statistically higher push-out bond strength values were detected in the cervical third for SBMP+ARC and SB+ARC (p<0.05). The U100 showed significantly more mixed failures than SBMP+ARC in the apical third (p<0.05). In conclusion, the self-adhesive cement RelyX U100 was the only cement not sensitive to the root canal region.

  20. Evaluation of Shear Bond Strength of Methacrylate- and Silorane-based Composite Resin Bonded to Resin-Modified Glass-ionomer Containing Micro- and Nano-hydroxyapatite

    PubMed Central

    Sharafeddin, Farahnaz; Moradian, Marzie; Motamedi, Mehran

    2016-01-01

    Statement of the Problem The adhesion of resin-modified glass-ionomer (RMGI) to composite resin has a very important role in the durability of sandwich restorations. Hydroxyapatite is an excellent candidate as a filler material for improving the mechanical properties of glass ionomer cement. Purpose The aim of this study was to assess the effect of adding micro- and nano-hydroxyapatite (HA) powder to RMGI on the shear bond strength (SBS) of nanofilled and silorane-based composite resins bonded to RMGI containing micro- and nano-HA. Materials and Method Sixty cylindrical acrylic blocks containing a hole of 5.5×2.5 mm (diameter × height) were prepared and randomly divided into 6 groups as Group 1 with RMGI (Fuji II LC) plus Adper Single Bond/Z350 composite resin (5.5×3.5 mm diameter × height); Group 2 with RMGI containing 25 wt% of micro-HA plus Adper Single Bond/Z350 composite resin; Group3 with RMGI containing 25 wt% of nano-HA plus Adper Single Bond/Z350 composite resin; Group 4 with RMGI plus P90 System Adhesive/P90 Filtek composite resin (5.5×3.5 mm diameter × height); Group 5 with RMGI containing 25 wt% of micro-HA plus P90 System Adhesive/P90Filtek composite resin; and Group 6 with RMGI containing 25 wt% of nano-HA plus P90 System Adhesive/P90 Filtek composite resin. The specimens were stored in water (37° C, 1 week) and subjected to 1000 thermal cycles (5°C/55°C). SBS test was performed by using a universal testing machine at a crosshead speed of 1 mm/min. Data were analyzed by two-way ANOVA and Tukey test (p< 0.05). Results There were significant differences between groups 1 and 4 (RMGI groups, p= 0.025), and groups 3 and 6 (RMGI+ nano-HA groups, p= 0.012). However, among Z350 and P90 specimens, no statistically significant difference was detected in the SBS values (p= 0.19, p= 0.083, respectively). Conclusion RMGI containing HA can improve the bond strength to methacrylate-based in comparison to silorane-based composite resins. Meanwhile, RMGI

  1. Easy-to-use interface

    SciTech Connect

    Blattner, M M; Blattner, D O; Tong, Y

    1999-04-01

    Easy-to-use interfaces are a class of interfaces that fall between public access interfaces and graphical user interfaces in usability and cognitive difficulty. We describe characteristics of easy-to-use interfaces by the properties of four dimensions: selection, navigation, direct manipulation, and contextual metaphors. Another constraint we introduced was to include as little text as possible, and what text we have will be in at least four languages. Formative evaluations were conducted to identify and isolate these characteristics. Our application is a visual interface for a home automation system intended for a diverse set of users. The design will be expanded to accommodate the visually disabled in the near future.

  2. Quick and Easy Classroom Makeover

    ERIC Educational Resources Information Center

    Adams, Caralee

    2006-01-01

    This article offers simple design ideas on classroom transformation that are easy on the pocketbook and will make the biggest difference to teachers and their students. These include: (1) Go with a splash of color; (2) Use bright fabrics; (3) Stick with blues and greens; (4) Use color to create nooks; (5) Buddy up with a shop class; (6) Hide the…

  3. Fast and Easy Website Tuneups

    ERIC Educational Resources Information Center

    Wisniewski, Jeff

    2008-01-01

    This article presents fast, easy and helpful hints for making web sites that people will want to use over and over again. These tips include: (1) Making sure that the website's copyright statement is up-to-date; (2) Adding "last updated" code to each webpage at the site; (3) Adding photos to the site's contact information; (4) Turning boring old…

  4. Easy-to-Make Cryophoruses

    ERIC Educational Resources Information Center

    Battino, Rubin; Letcher, Trevor M.

    2008-01-01

    The cryophorus dramatically demonstrates the cooling effect of evaporation. This article describes some simple and easy-to-make cryophoruses, ideal for demonstrating evaporative cooling to students at all levels. The most dramatic effects occurred with cyclohexane and benzene, with water generally freezing more slowly. (Contains 4 notes, 2 tables,…

  5. Interaction morphology and bond strength of nanofilled simplified-step adhesives to acid etched dentin

    PubMed Central

    Di Hipólito, Vinicius; Reis, André Figueiredo; Mitra, Sumita B.; de Goes, Mario Fernando

    2012-01-01

    Objective: To evaluate the effect of nanofillers incorporated into adhesives on the microtensile bond strength (μ-TBS) and interfacial micromorphology to dentin. Methods: The occlusal enamel of 5 human molars was removed and each tooth sectioned into four quarters. The exposed dentin was treated with one of the following adhesives: Adper Single Bond (SB-unfilled), OptiBond Solo Plus (OS-barium aluminoborosilicate, 400nm Ø), Prime & Bond NT (NT-colloidal silica, 7–40 nm Ø) and Adper Single Bond 2 (SB2-colloidal silica, 5nm Ø). Cylinders of resin-based composite were constructed on the adhesive layers. After 24-hour storage, the restored tooth-quadrants were sectioned to obtain stick-shaped specimens (0.8 mm2, cross-sectional area) and submitted to μ-TBS at a cross-speed of 0.5 mm/min. Data were analyzed using one-way ANOVA and Tukey’s test (alpha = .05). Twenty-eight additional teeth were used for interfacial micro-morphologic analysis by SEM (16-teeth) and TEM (12-teeth). The dentin surfaces of 32 discs were treated with the adhesives (8 discs for adhesive) and laminated to form disc-pairs using a flowable resin composite for SEM/EDS analysis. For TEM, 90nm-thick nondemineralized unstained sections were processed. Results: SB2 showed significant higher bond strength than SB, OS and NT. The SEM/EDS and TEM analysis revealed nanofillers infiltrated within the interfibrillar spaces of the SB2-hybrid layer. Fillers were concentrated around patent tubular orifices and in the adhesive layer for OS and NT. Conclusion: The presence of nanofillers within the interfibrillar spaces of the SB2-hybrid layer suggests its importance in the improvement of the μ-TBS. PMID:23077413

  6. Making Difficult Things Easy and Easy Things Difficult.

    ERIC Educational Resources Information Center

    Campbell, J. Arthur; Bent, Henry A.

    1982-01-01

    Suggestions are offered to illustrate concepts and processes by using simple materials such as paper, paper clip, rubber band (bonding, entropy, endothermic processes). Also suggests using basic terminology: elementary ratios, percent, reaction chemistry for entropy function; equilibrium constants for Gibbs energies; and chemical mechanics for…

  7. Effect of Bleaching and Thermocycling on Resin-Enamel Bond Strength

    PubMed Central

    Moosavi, Horieh; Mohammadipour, Hamideh Sadat; Ghavamnasiri, Marjaneh; Alizadeh, Sanaz

    2015-01-01

    The aim of this study was to evaluate the effect of bleaching and thermocycling on microshear bond strength of bonded resin composites to enamel. Enamel slices were prepared from ninety-six intact human premolars and resin composite cylinders were bonded by using Adper Single Bond 2 + Filtek Z350 or Filtek silorane adhesive and resin composite. Each essential group was randomly subdivided to two subgroups: control and bleaching. In bleaching group, 35% hydrogen peroxide was applied on samples. Thermocycling procedure was conducted between 5°C and 55°C, for 3.000 cycles on the half of each subgroup specimen. Then microshear bond strength was tested. Methacrylate-based resin composite had higher bond strength than silorane-based one. The meyhacrylate-based group without bleaching along with thermocycling showed the most bond strength, while bleaching with 35% carbamide peroxide on silorane-based group without thermocycling showed the least microshear bond strength. Bleaching caused a significant degradation on shear bond strength of silorane-based resin composites that bonded using self-etch adhesive resin systems. PMID:26839550

  8. Effect of Bleaching and Thermocycling on Resin-Enamel Bond Strength.

    PubMed

    Moosavi, Horieh; Mohammadipour, Hamideh Sadat; Ghavamnasiri, Marjaneh; Alizadeh, Sanaz

    2015-01-01

    The aim of this study was to evaluate the effect of bleaching and thermocycling on microshear bond strength of bonded resin composites to enamel. Enamel slices were prepared from ninety-six intact human premolars and resin composite cylinders were bonded by using Adper Single Bond 2 + Filtek Z350 or Filtek silorane adhesive and resin composite. Each essential group was randomly subdivided to two subgroups: control and bleaching. In bleaching group, 35% hydrogen peroxide was applied on samples. Thermocycling procedure was conducted between 5°C and 55°C, for 3.000 cycles on the half of each subgroup specimen. Then microshear bond strength was tested. Methacrylate-based resin composite had higher bond strength than silorane-based one. The meyhacrylate-based group without bleaching along with thermocycling showed the most bond strength, while bleaching with 35% carbamide peroxide on silorane-based group without thermocycling showed the least microshear bond strength. Bleaching caused a significant degradation on shear bond strength of silorane-based resin composites that bonded using self-etch adhesive resin systems. PMID:26839550

  9. Effects of simplified ethanol-wet bonding technique on immediate bond strength with normal versus caries-affected dentin

    PubMed Central

    Aggarwal, Vivek; Singla, Mamta; Sharma, Ritu; Miglani, Sanjay; Bhasin, Saranjit Singh

    2016-01-01

    Aim: The aim of the present study was to evaluate whether the use of simplified ethanol-wet bonding (EWB) technique improved the immediate microtensile bond strength (μTBS) between resin composite and caries-affected dentin (CAD). Materials and Methods: Twenty-four extracted carious human permanent molars were sectioned to expose the carious lesion. The carious dentin was excavated until CAD was exposed. The samples were divided into two groups: water-wet bonding with Adper Scotchbond Multi-Purpose and a simplified EWB (three 100% ethanol applications for 30 s each), followed by application of an experimental hydrophobic primer and restoration. The samples were vertically sectioned to produce 1 mm × 1 mm thick slabs. The normal dentin (ND) slabs and CAD slabs were identified and were subjected to μTBS evaluation. Slabs from four teeth (two from each group) were evaluated under microscope. Data were analyzed using two-way ANOVA and post hoc Holm–Sidak test at P < 0.05. Results: EWB improved the μTBS in ND but not in CAD group. The dentinal tubules in CAD group showed sclerotic activity with minimal or no hybrid layer. Conclusions: Simplified ethanol bonding does not improve the bond strength in CAD.

  10. Effects of simplified ethanol-wet bonding technique on immediate bond strength with normal versus caries-affected dentin

    PubMed Central

    Aggarwal, Vivek; Singla, Mamta; Sharma, Ritu; Miglani, Sanjay; Bhasin, Saranjit Singh

    2016-01-01

    Aim: The aim of the present study was to evaluate whether the use of simplified ethanol-wet bonding (EWB) technique improved the immediate microtensile bond strength (μTBS) between resin composite and caries-affected dentin (CAD). Materials and Methods: Twenty-four extracted carious human permanent molars were sectioned to expose the carious lesion. The carious dentin was excavated until CAD was exposed. The samples were divided into two groups: water-wet bonding with Adper Scotchbond Multi-Purpose and a simplified EWB (three 100% ethanol applications for 30 s each), followed by application of an experimental hydrophobic primer and restoration. The samples were vertically sectioned to produce 1 mm × 1 mm thick slabs. The normal dentin (ND) slabs and CAD slabs were identified and were subjected to μTBS evaluation. Slabs from four teeth (two from each group) were evaluated under microscope. Data were analyzed using two-way ANOVA and post hoc Holm–Sidak test at P < 0.05. Results: EWB improved the μTBS in ND but not in CAD group. The dentinal tubules in CAD group showed sclerotic activity with minimal or no hybrid layer. Conclusions: Simplified ethanol bonding does not improve the bond strength in CAD. PMID:27656059

  11. EASI - EQUILIBRIUM AIR SHOCK INTERFERENCE

    NASA Technical Reports Server (NTRS)

    Glass, C. E.

    1994-01-01

    New research on hypersonic vehicles, such as the National Aero-Space Plane (NASP), has raised concerns about the effects of shock-wave interference on various structural components of the craft. State-of-the-art aerothermal analysis software is inadequate to predict local flow and heat flux in areas of extremely high heat transfer, such as the surface impingement of an Edney-type supersonic jet. EASI revives and updates older computational methods for calculating inviscid flow field and maximum heating from shock wave interference. The program expands these methods to solve problems involving the six shock-wave interference patterns on a two-dimensional cylindrical leading edge with an equilibrium chemically reacting gas mixture (representing, for example, the scramjet cowl of the NASP). The inclusion of gas chemistry allows for a more accurate prediction of the maximum pressure and heating loads by accounting for the effects of high temperature on the air mixture. Caloric imperfections and specie dissociation of high-temperature air cause shock-wave angles, flow deflection angles, and thermodynamic properties to differ from those calculated by a calorically perfect gas model. EASI contains pressure- and temperature-dependent thermodynamic and transport properties to determine heating rates, and uses either a calorically perfect air model or an 11-specie, 7-reaction reacting air model at equilibrium with temperatures up to 15,000 K for the inviscid flowfield calculations. EASI solves the flow field and the associated maximum surface pressure and heat flux for the six common types of shock wave interference. Depending on the type of interference, the program solves for shock-wave/boundary-layer interaction, expansion-fan/boundary-layer interaction, attaching shear layer or supersonic jet impingement. Heat flux predictions require a knowledge (from experimental data or relevant calculations) of a pertinent length scale of the interaction. Output files contain flow

  12. Evaluating the bonding of two adhesive systems to enamel submitted to whitening dentifrices.

    PubMed

    Briso, André Luiz Fraga; Toseto, Roberta Mariano; de Arruda, Alex Mendes; Tolentino, Patricia Ramos; de Alexandre, Rodrigo Sversut; dos Santos, Paulo Henrique

    2010-01-01

    The aim of this study was to evaluate by micro-shear bond strength test, the bond strength of composite resin restoration to enamel submitted to whitening dentifrices. Forty bovine teeth were embedded in polystyrene resin and polished. The specimens were randomly divided into eight groups (n=5), according to the dentifrice (carbamide peroxide, hydrogen peroxide and conventional dentifrice) and the adhesive system (Prime & Bond 2.1 and Adper Single Bond 2). Dentifrice was applied for 15 minutes a day, for 21 days. Thirty minutes after the last exposure to dentifrice, the samples were submitted to a bonding procedure with the respective adhesive system. After that, four buttons of resin were bonded in each sample using transparent cylindrical molds. After 24 hours, the teeth were submitted to the micro-shear bond strength test and subsequent analysis of the fracture mode. Data were submitted to analysis of variance and Fisher's PLSD test (alpha = 0.05). The micro-shear bond strength showed no difference between adhesives systems but a significant reduction was found between the control and carbamide groups (p = 0.0145) and the control and hydrogen groups (p = 0.0370). The evaluation of the failures modes showed that adhesive failures were predominant. Cohesive failures were predominant in group IV The use of dentifrice with peroxides can decrease bonding strength in enamel.

  13. Bent Bonds and Multiple Bonds.

    ERIC Educational Resources Information Center

    Robinson, Edward A.; Gillespie, Ronald J.

    1980-01-01

    Considers carbon-carbon multiple bonds in terms of Pauling's bent bond model, which allows direct calculation of double and triple bonds from the length of a CC single bond. Lengths of these multiple bonds are estimated from direct measurements on "bent-bond" models constructed of plastic tubing and standard kits. (CS)

  14. Effect of Self-etching Adhesives on the Bond Strength of Glass-Ionomer Cements

    PubMed Central

    Jaberi Ansari, Zahra; Panahandeh, Narges; Tabatabaei Shafiei, Zahra Sadat; Akbarzadeh Baghban, Alireza

    2014-01-01

    Objective: Statement of Problem: Adequate bond strength between glass ionomer cements and composite resin is necessary for the success of the sandwich technique. Purpose of Study: This study assessed the micro-shear bond strength of composite resin to glass-ionomer cements (GIC) using self-etch adhesives with different pH values. Materials and Methods: One hundred specimens (6×4×2 mm) were made using Fuji II and Fuji II LC GICs and treated with different adhesives as follows: Group 1:Fuji II+ Adper Prompt L-Pop, Group-2: Fuji II+SE bond, Group-3: Fuji II + AdheSE, Group-4:Fuji II+ Protect bond, Group-5: Fuji II + Single bond, Group-6:Fuji II LC+ Adper Prompt LPop, Group-7: Fuji II LC+SE bond, Group-8:Fuji II LC+ AdheSE, Group-9: Fuji II LC+ Protect bond, and Group-10: Fuji II LC+ Single bond. Each group consisted of 10 specimens. A cylinder of Z100 composite resin was placed on each sample and light cured. After 24 hours of water storage (37°C), the specimens were subjected to micro-shear bond strength tests (0.5 mm/min). Data were analyzed using two-way ANOVA and Tukey’s test. Results: The mean micro-shear bond strength of groups 1–10 was 11.66±1.79, 16.50±1.85, 18.47±1.77, 13.95±1.77, 15.27±1.49, 15.14±0.90, 20.03±1.19, 17.48±3.00, 16.24±1.98 and 16.03±1.49 MPa, respectively. There were significant differences between groups 1 and 7 (P<0.05). No significant difference was observed between other groups (P>0.05). Fuji II LC showed higher bond strength than Fuji II (P<0.05). Conclusion: Type of self-etch adhesive had no significant effect on micro-shear bond strength of glass-ionomer to composite resin. Resin modified glass ionomer cement (RMGIC) exhibited higher bond strength than the conventional GIC. PMID:25628698

  15. Effect of 10% Sodium Ascorbate on Shear Bond Strength of Bleached Teeth - An in-vitro Study

    PubMed Central

    Ponnappa, K C; Nitin, Mirdha; Ramesh, Sachhi; Sharanappa, Kambale; Nishant, Ajgaonkar

    2015-01-01

    Background Patient often requires some additional interventions such as replacement of old restorations, laminates and veneers after bleaching, for aesthetic purposes. The residual oxygen inhibits polymerization of resin based materials which results in reduced bond strength of the restorations. Some techniques are available to solve the clinical problems related to the post bleach compromised bond strength. Objectives The purpose of this study is to evaluate, the role of 10% sodium ascorbate on reversing the compromised bond strength and compare enamel shear bond strength of 5th and 6th generation dentine bonding agents on bleached and unbleached teeth. Materials and Methods Eighty freshly extracted human anterior teeth were assigned in to Group A and Group B of 40 teeth each. Samples in both groups were subdivided in to 4 subgroups of 10 teeth each. In Group A composite resins was bonded using 5th generation dentine bonding agent (3M Single Bond) and Group B was bonded using 6th generation (3M ESPE Adper SE Plus). Subgroups were subjected to the procedure as, A1;B1 etching and bonding (control), A2; B2 bleaching, etching and immediate bonding, A3; B3 bleaching,10% ascorbic acid treatment for 10 minutes after that etching and bonding immediately, A4; B4 bleaching, storage in artificial saliva for 4 days and then etching and bonding. Pola office, in office bleach (SDI (082216) was used for bleaching. The specimens were subjected to shear load in a Universal testing machine to evaluate bond strength. Results A decrease in bond strength was seen with 6th generation adhesive system compared to 5th generation bonding system, which is statistically significant, p<0.001. Conclusion Treating the bleached enamel surfaces when treated with 10% sodium ascorbate, which reverses the compromised bond strength and is a good alternative to delayed bonding. PMID:26393201

  16. “Evaluation of shear bond strength of a composite resin to white mineral trioxide aggregate with three different bonding systems”-An in vitro analysis

    PubMed Central

    Patil, Anand C.

    2016-01-01

    Background Mineral trioxide aggregate (MTA) is a biomaterial that has been investigated for endodontic applications. With the increased use of MTA in pulp capping, pulpotomy, perforation repair, apexification and obturation, the material that would be placed over MTA as a final restoration is an important matter. As composite resins are one of the most widely used final restorative materials, this study was conducted to evaluate the shear bond strength of a composite resin to white mineral trioxide aggregate (WMTA) using three different bonding systems namely the two-step etch and rinse adhesive, the self-etching primer and the All-in-one system. Material and Methods Forty five specimens of white MTA (Angelus) were prepared and randomly divided into three groups of 15 specimens each depending on the bonding systems used respectively. In Group A, a Two-step etch and rinse adhesive or ‘total-etch adhesive’, Adper Single Bond 2 (3M/ESPE) and Filtek Z350 (3M ESPE, St Paul, MN) were placed over WMTA. In group B, a Two-step self-etching primer system, Clearfil SE Bond (Kuraray, Medical Inc) and Filtek Z350 were used. In Group C, an All-in-one system, G Bond (GC corporation, Tokyo, Japan) and Filtek Z350 were used. The shear bond strength was measured for all the specimens. The data obtained was subjected to One way Analysis of Variance (ANOVA) and Scheffe’s post hoc test. Results The results suggested that the Two-step etch and rinse adhesive when used to bond a composite resin to white MTA gave better bond strength values and the All-in-one exhibited the least bond strength values. Conclusions The placement of composite used with a Two-step etch and rinse adhesive over WMTA as a final restoration may be appropriate. Key words:Composite resins, dentin bonding agents, mineral trioxide aggregate, shear bond strength. PMID:27398177

  17. Bond strength of adhesives to dentin contaminated with smoker's saliva.

    PubMed

    Pinzon, Lilliam M; Oguri, Makoto; O'Keefe, Kathy; Dusevish, Vladimir; Spencer, Paulette; Powers, John M; Marshall, Grayson W

    2010-02-01

    The purpose of this study was to determine the effects of contamination with smoker's and non-smoker's saliva on the bond strength of resin composite to superficial dentin using different adhesive systems. The interfacial structure between the resin and dentin was evaluated for each treatment using environmental scanning electron microscopy (ESEM). Freshly extracted human molars were ground with 600-grit SiC paper to expose the superficial dentin. Adhesives [One-Up-Bond-F-Plus (OUFP) and Adper-Prompt-L-Pop (APLP)] and resin composite (TPHSpectrum) were bonded to the dentin (n = 8/group, 180 total specimens) under five surface conditions: control (adhesive applied following manufacturers' instructions); saliva, then 5-s air dry, then adhesive; adhesive, saliva, 5-s air dry; adhesive, saliva, 5-s water rinse, 5-s air dry (ASW group); and adhesive, saliva, 5-s water rinse, 5-s air dry, reapply adhesive (ASWA group). After storage in water at 37 degrees C for 24 h, the specimens were debonded under tension at a speed of 0.5 mm/min. ESEM photomicrographs of the dentin/adhesive interfaces were taken. Mean bond strength ranged from 8.1 to 24.1 MPa. Fisher's protected least significant difference (P = 0.05) intervals for critical adhesive, saliva, and surface condition differences were 1.3, 1.3, and 2.1 MPa, respectively. There were no significant differences in bond strength to dentin between contamination by smoker's and nonsmoker's saliva, but bond strengths were significantly different between adhesive systems, with OUFP twice as strong as APLP under almost all conditions. After adhesive application and contamination with either smoker's or nonsmoker's saliva followed by washing and reapplication of the adhesive (ASWA group), the bond strength of both adhesive systems was the same as that of the control group.

  18. Assessment of the Shear Bond Strength between Nanofilled Composite Bonded to Glass-ionomer Cement Using Self-etch Adhesive with Different pHs and Total-Etch Adhesive

    PubMed Central

    Sharafeddin, Farahnaz; Choobineh, Mohammad Mehdi

    2016-01-01

    Statement of the Problem In the sandwich technique, the undesirable bond between the composite resin and glass-ionomer cement (GIc) is one of the most important factors which lead to the failure of restoration. Total-etch and self-etch adhesives may improve the bond strength based on their pH. Purpose The purpose of this study was to evaluate the shear bond strength between the nanofilled composite resin and GIc using different adhesives. Materials and Method In this experimental study, 40 specimens (6×6mm) in 4 groups (n=10) were prepared in acrylic mold. Each specimen contained conventional GI ChemFil Superior with a height of 3mm, bonded to Z350 composite resin with a height measured 3mm. In order to bond the composite to the GI, the following adhesives were used, respectively: A: mild Clearfil SE Bond self-etch (pH=2), B: intermediate OptiBond self-etch (pH=1.4), C: strong Adper Prompt L-Pop (pH=1), and D: Adper Single Bond 2 total-etch (pH=7.2). The shear bond strength was measured by using universal testing machine with a crosshead speed of 1mm/min. One-way ANOVA and Tukey’s test were used to analyze the data (p< 0.05). Results The shear bond strength in group A was significantly higher than group B (p= 0.002), C (p< 0.001), and D (p< 0.001). Moreover, the shear bond strength of groups A and B (self-etch) was significantly different from group D (total-etch) (p< 0.001); and C (self-etch) with D (p= 0.024). Conclusion The results of this study showed that applying the mild self-etch adhesive between the composite and the GIc results in stronger shear bond strength compared to intermediate and strong self-etch adhesives. Moreover, the self-etch adhesive increased the shear bond strength between composite resin and GIc more significantly than total-etch adhesive. PMID:26966701

  19. Bonding efficacy of etch-and-rinse adhesives after dentin biomodification using ethanol saturation and collagen cross-linker pretreatment

    PubMed Central

    Sharma, Pallavi; Nagpal, Rajni; Tyagi, Shashi Prabha; Manuja, Naveen

    2015-01-01

    Aim: To evaluate whether the application of two simplified etch-and-rinse adhesives to biomodified dentin using ethanol-wet bonding (EWB) and collagen cross-linker (CCL) pretreatment improves their sealing ability. Materials and Methods: In 176 extracted human molars, the pulp-chambers were deroofed, and teeth were sectioned horizontally. Samples were randomly divided into eight groups according to four bonding techniques using two simplified etch-and-rinse adhesives; Adper Single Bond 2 (ASB) and XP Bond (XPB). The bonding protocols included: (a) Water-wet bonding (WWB); (b) EWB; (c) WWB and CCL application; (d) EWB and CCL application. After composite resin restorations, dye leakage evaluation and scanning electron microscope analysis were done. Leakage scores were statistically analyzed using Kruskal-Wallis and Mann-Whitney U tests at a significance level of P < 0.05. Result: For both ASB and XPB adhesives, least dye leakage was observed in EWB groups (b and d) (P = 0.918 and P = 0.399 respectively) which showed no significant difference, while maximum leakage scores were seen in WWB groups (a and c). Regardless of CCL application and adhesives used, EWB technique depicted (P = 0.003 and P = 0.004) significantly greater sealing ability than WWB. Conclusion: Bonding of ASB and XPB using EWB significantly improved their sealing ability. Biomodification using CCL pretreatment had no significant effect on the sealing ability of adhesives bonded with either WWB or EWB. PMID:26180421

  20. Bond Issues.

    ERIC Educational Resources Information Center

    Pollack, Rachel H.

    2000-01-01

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

  1. Sticker Bonding.

    ERIC Educational Resources Information Center

    Frazier, Laura Corbin

    2000-01-01

    Introduces a science activity on the bonding of chemical compounds. Assigns students the role of either a cation or anion and asks them to write the ions they may bond with. Assesses students' understanding of charge, bonding, and other concepts. (YDS)

  2. Using EasyNet in Libraries.

    ERIC Educational Resources Information Center

    Still, Julie

    1991-01-01

    Describes EasyNet, a gateway service that allows users access to over 900 databases. Use of EasyNet at the University of Richmond (Virginia) libraries is explained, search strategies are discussed, problems with the price structure are examined, and its use both as an end-user service and for mediated searching is described. (LRW)

  3. Petroleomics by EASI(+/-) FT-ICR MS.

    PubMed

    Corilo, Yuri E; Vaz, Boniek G; Simas, Rosineide C; Nascimento, Heliara D Lopes; Klitzke, Clécio F; Pereira, Rosana C L; Bastos, Wagner L; Santos Neto, Eugênio V; Rodgers, Ryan P; Eberlin, Marcos N

    2010-05-15

    An ambient ionization/desorption technique, namely, easy ambient sonic-spray ionization mass spectrometry (EASI), has been applied to crude oil samples. From a single droplet of the sample placed on an inert surface, EASI(+/-) is shown to promote efficient desorption and ionization of a myriad of polar components via the action of its cloud of very minute supersonic bipolar charged droplets. The gaseous [M + H](+) and [M - H](-) ions concurrently formed by EASI(+/-) were analyzed by Fourier transform mass spectrometry (FT-ICR MS), and a total of approximately 6000 acidic and basic components have been attributed. EASI(+/-) FT-ICR MS of crude oils is show to be almost as fast as ESI(+)/ESI(-) FT-ICR MS, providing similar compositional information of polar components and spectral quality comparable to that of a commercial nonochip-based robotic ESI device. EASI(+/-) requires no sample workup thus eliminating risks of contamination during sample manipulation and memory effects because of carry over in pumping ESI lines. More importantly, EASI(+/-) is a voltage-free ionization technique therefore eliminating risks of redox processes or duality of ionization mechanisms that can be observed in voltage-assisted processes. Data visualization via typical petroleomic plots confirms the similarity of the compositional information provided by EASI(+/-) compared to ESI(+)/ESI(-). The ambient EASI(+/-) FT-ICR MS method requires no voltage switching in changing the ion polarity mode, offering a workup, heating and voltage-free protocol for petroleomic studies performed at open atmosphere directly on the undisturbed crude oil sample.

  4. Effect of Intermediate Agents and Preheated Composites on Repair Bond Strength of Silorane-Based Composites

    PubMed Central

    Shafiei, Fereshteh; Daryadar, Marzieh

    2015-01-01

    Objectives: Repairing composite restorations is a challenging procedure especially when two different types of composites are used. This study aimed to compare the repair strength of silorane-based composite (SC) (Filtek P90) with that of preheated SC, methacrylate composite (MC)(Z250), flowable MC (Filtek Supreme Plus) and different adhesive/composite combinations. Materials and Methods: Eighty-four SC specimens were fabricated and randomly divided into seven groups (G). In the control group (G7), SC was bonded immediately to SC. The other specimens were water-aged for two months and were then roughened, etched and repaired with the following materials: G1) Silorane Adhesive Bond (SAB)/SC; G2) Preheated SC; G3) SAB/MC; G4) Adper Single Bond (SB)/MC; G5) Flowable MC/MC; G6) Preheated MC. After water storage and thermocycling, the repaired specimens were subjected to shear bond strength testing. The data were analyzed using ANOVA and Tukey’s test. Results: Preheated SC and MC, flowable MC and SAB/SC resulted in bond strength comparable to that of the control group. Preheated SC showed significantly higher bond strength when compared to SAB/MC (P=0.04) and SB/MC (P<0.001). Bond strength of SB/MC was significantly lower than that of the other groups (P<0.05), except for SAB/SC and SAB/MC. Conclusion: All repairing materials except for SB/MC resulted in bond strength values comparable to that of the control group. Repair with preheated SC yielded the highest bond strength. PMID:27148378

  5. Dentin surface treatment using a non-thermal argon plasma brush for interfacial bonding improvement in composite restoration.

    PubMed

    Ritts, Andy C; Li, Hao; Yu, Qingsong; Xu, Changqi; Yao, Xiaomei; Hong, Liang; Wang, Yong

    2010-10-01

    The objective of this study was to investigate the treatment effects of non-thermal atmospheric gas plasmas on dentin surfaces used for composite restoration. Extracted unerupted human third molars were prepared by removing the crowns and etching the exposed dentin surfaces with 35% phosphoric acid gel. The dentin surfaces were treated using a non-thermal atmospheric argon plasma brush for various periods of time. The molecular changes of the dentin surfaces were analyzed using Fourier transform infrared spectrophotometry/attenuated total reflectance (FTIR/ATR), and an increase in the amount of carbonyl groups was detected on plasma-treated dentin surfaces. Adper Single Bond Plus adhesive and Filtek Z250 dental composite were applied as directed. To evaluate the dentin/composite interfacial bonding, the teeth thus prepared were sectioned into micro-bars and analyzed using tensile testing. Student-Newman-Keuls tests showed that the bonding strength of the composite restoration to peripheral dentin was significantly increased (by 64%) after 30 s of plasma treatment. However, the bonding strength to plasma-treated inner dentin did not show any improvement. It was found that plasma treatment of the peripheral dentin surface for up to 100 s resulted in an increase in the interfacial bonding strength, while prolonged plasma treatment of dentin surfaces (e.g. 5 min) resulted in a decrease in the interfacial bonding strength.

  6. Push-Out Bond Strength of Restorations with Bulk-Fill, Flow, and Conventional Resin Composites

    PubMed Central

    Caixeta, Rodrigo Vieira; Guiraldo, Ricardo Danil; Kaneshima, Edmilson Nobumitu; Barbosa, Aline Silvestre; Picolotto, Cassiana Pedrotti; Lima, Ana Eliza de Souza; Gonini Júnior, Alcides; Berger, Sandrine Bittencourt

    2015-01-01

    The aim of this study was to evaluate the bond strengths of composite restorations made with different filler amounts and resin composites that were photoactivated using a light-emitting diode (LED). Thirty bovine incisors were selected, and a conical cavity was prepared in the facial surface of each tooth. All preparations were etched with Scotchbond Etching Gel, the Adper Scotchbond Multipurpose Plus adhesive system was applied followed by photoactivation, and the cavities were filled with a single increment of Filtek Z350 XT, Filtek Z350 XT Flow, or bulk-fill X-tra fil resin composite (n = 10) followed by photoactivation. A push-out test to determine bond strength was conducted using a universal testing machine. Data (MPa) were submitted to Student's t-test at a 5% significance level. After the test, the fractured specimens were examined using an optical microscope under magnification (10x). Although all three composites demonstrated a high prevalence of adhesive failures, the bond strength values of the different resin composites photoactivated by LED showed that the X-tra fil resin composite had a lower bond strength than the Filtek Z350 XT and Filtek Z350 XT Flow resin composites. PMID:26457322

  7. Effect of surface treatments on the bond strength of a resin cement to commercially pure titanium.

    PubMed

    de Almeida-Júnior, Antonio Alves; Fonseca, Renata Garcia; Haneda, Isabella Gagliardi; Abi-Rached, Filipe de Oliveira; Adabo, Gelson Luis

    2010-01-01

    Investigation of the effectiveness of surface treatments that promote a strong bond strength of resin cements to metals can contribute significantly to the longevity of metal-ceramic restorations. This study evaluated the effect of surface treatments on the shear bond strength (SBS) of a resin cement to commercially pure titanium (CP Ti). Ninety cast CP Ti discs were divided into 3 groups (n=30), which received one of the following airborne-particle abrasion conditions: (1) 50 microm Al(2)O(3) particles; (2) 30 microm silica-modified Al(2)O(3) particles (Cojet Sand); (3) 110 microm silica-modified Al(2)O(3) particles (Rocatec). For each airborne-particle abrasion condition, the following post-airborne-particle abrasion treatments were used (n=10): (1) none; (2) adhesive Adper Single Bond 2; (3) silane RelyX Ceramic Primer. RelyX ARC resin cement was bonded to CP Ti surfaces. All specimens were thermally cycled before being tested in shear mode. Failure mode was determined. The best association was Rocatec plus silane. All groups showed 100% adhesive failure. There were combinations that promote higher SBS than the protocol recommended by the manufacturer of RelyX ARC. PMID:20640356

  8. Shear bond strength of resin cement to an acid etched and a laser irradiated ceramic surface

    PubMed Central

    Motro, Pelin Fatma Karagoz; Yurdaguven, Haktan

    2013-01-01

    PURPOSE To evaluate the effects of hydrofluoric acid etching and Er,Cr:YSGG laser irradiation on the shear bond strength of resin cement to lithium disilicate ceramic. MATERIALS AND METHODS Fifty-five ceramic blocks (5 mm × 5 mm × 2 mm) were fabricated and embedded in acrylic resin. Their surfaces were finished with 1000-grit silicon carbide paper. The blocks were assigned to five groups: 1) 9.5% hydrofluoric-acid etching for 60 s; 2-4), 1.5-, 2.5-, and 6-W Er,Cr:YSGG laser applications for 60 seconds, respectively; and 5) no treatment (control). One specimen from each group was examined using scanning electron microscopy. Ceramic primer (Rely X ceramic primer) and adhesive (Adper Single Bond) were applied to the ceramic surfaces, followed by resin cement to bond the composite cylinders, and light curing. Bonded specimens were stored in distilled water at 37℃ for 24 hours. Shear bond strengths were determined by a universal testing machine at 1 mm/min crosshead speed. Data were analyzed using Kruskal-Wallis and Mann-Whitney U-tests (α=0.05). RESULTS Adhesion was significantly stronger in Group 2 (3.88 ± 1.94 MPa) and Group 3 (3.65 ± 1.87 MPa) than in Control group (1.95 ± 1.06 MPa), in which bonding values were lowest (P<.01). No significant difference was observed between Group 4 (3.59 ± 1.19 MPa) and Control group. Shear bond strength was highest in Group 1 (8.42 ± 1.86 MPa; P<.01). CONCLUSION Er,Cr:YSGG laser irradiation at 1.5 and 2.5 W increased shear bond strengths between ceramic and resin cement compared with untreated ceramic surfaces. Irradiation at 6 W may not be an efficient ceramic surface treatment technique. PMID:23755333

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

    PubMed

    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.

  10. Teaching is Easy Courseware Authoring System.

    ERIC Educational Resources Information Center

    Huehner, David R.

    1986-01-01

    Provides a narrative review of a teacher microcomputer authoring system called Teaching is Easy (National Collegiate Software Clearing House, 1983). This simplified menu-driven authoring system allows the teacher to create class-specific drill and practice exercises on IBM PC or 100% compatible clones. Reported cost is $20, and learning time is…

  11. Interpreting Histograms. As Easy as It Seems?

    ERIC Educational Resources Information Center

    Lem, Stephanie; Onghena, Patrick; Verschaffel, Lieven; Van Dooren, Wim

    2014-01-01

    Histograms are widely used, but recent studies have shown that they are not as easy to interpret as it might seem. In this article, we report on three studies on the interpretation of histograms in which we investigated, namely, (1) whether the misinterpretation by university students can be considered to be the result of heuristic reasoning, (2)…

  12. Schoolyard Science: 101 Easy and Inexpensive Activities

    ERIC Educational Resources Information Center

    Lord, Thomas R.; Travis, Holly J.

    2011-01-01

    With 101 easy and inexpensive activities to do on school grounds, "Schoolyard Science" can help students develop their observation and inquiry skills as well as an appreciation of their outdoor environment. Covering topics such as lower plants, gardens, insects and other invertebrates, energy, and Earth science, Thomas Lord and Holly Travis…

  13. Six Easy Steps to Online Success

    ERIC Educational Resources Information Center

    Rose, Richard

    2011-01-01

    Against his better instincts, the author, an educator at West Texas A&M University, shares his school's recipe for developing a successful online learning program. He discusses six easy steps to online success. These include: (1) clean up one's act; (2) answers in 24 hours; (3) plenty of structure; (4) format phone conferences at midterm; (5) do…

  14. Effect of desensitizing agents on the microtensile bond strength of two-step etch-and-rinse adhesives to dentin.

    PubMed

    Cortiano, Fernanda M; Rached, Rodrigo N; Mazur, Rui F; Vieira, Sergio; Freire, Andrea; de Souza, Evelise M

    2016-06-01

    Desensitizers can be used to control postoperative sensitivity in adhesive restorations. The aim of this study was to evaluate the effect of desensitizing agents on the bond strength of two-step etch-and-rinse adhesive systems to dentin. Forty-two human molars were sectioned to obtain 3-mm-thick dentin discs. The discs were divided into three groups (n = 14 in each) - no-treatment control group (CT), and oxalic acid [BisBlock (BB)] and calcium phosphate [Desensibilize Nano-P (NP)] desensitizers - before the application of two adhesive systems [Adper Single Bond Plus (SB) and One-Step Plus (OSP)]. A nanoparticle composite resin was used to create a 3-mm-thick build-up. The specimens were stored in distilled water for 24 h before a microtensile bond-strength test was performed. The failure modes were determined using a stereomicroscope at 100 × magnification. Specimens were sectioned perpendicular to the interface for scanning electron microscopy analyses. The CT-SB group exhibited the highest bond strength, differing significantly from BB-SB and BB-OSP groups. Mixed failures were prevalent for all groups. Scanning electron microscopy revealed a continuous hybrid layer and resin tags in all groups. Dentin bond strength of etch-and-rinse adhesive systems was reduced by an oxalic acid desensitizer but was not affected by a calcium phosphate-containing desensitizer. PMID:27038226

  15. Distinguishing Bonds.

    PubMed

    Rahm, Martin; Hoffmann, Roald

    2016-03-23

    The energy change per electron in a chemical or physical transformation, ΔE/n, may be expressed as Δχ̅ + Δ(VNN + ω)/n, where Δχ̅ is the average electron binding energy, a generalized electronegativity, ΔVNN is the change in nuclear repulsions, and Δω is the change in multielectron interactions in the process considered. The last term can be obtained by the difference from experimental or theoretical estimates of the first terms. Previously obtained consequences of this energy partitioning are extended here to a different analysis of bonding in a great variety of diatomics, including more or less polar ones. Arguments are presented for associating the average change in electron binding energy with covalence, and the change in multielectron interactions with electron transfer, either to, out, or within a molecule. A new descriptor Q, essentially the scaled difference between the Δχ̅ and Δ(VNN + ω)/n terms, when plotted versus the bond energy, separates nicely a wide variety of bonding types, covalent, covalent but more correlated, polar and increasingly ionic, metallogenic, electrostatic, charge-shift bonds, and dispersion interactions. Also, Q itself shows a set of interesting relations with the correlation energy of a bond.

  16. Bond strength of adhesives to dentin contaminated with smoker’s saliva

    PubMed Central

    Oguri, Makoto; O’Keefe, Kathy; Dusevish, Vladimir; Spencer, Paulette; Powers, John M.; Marshall, Grayson W.

    2010-01-01

    The purpose of this study was to determine the effects of contamination with smoker’s and non-smoker’s saliva on the bond strength of resin composite to superficial dentin using different adhesive systems. The interfacial structure between the resin and dentin was evaluated for each treatment using environmental scanning electron microscopy (ESEM). Freshly extracted human molars were ground with 600-grit SiC paper to expose the superficial dentin. Adhesives [One-Up-Bond-F-Plus (OUFP) and Adper-Prompt-L-Pop (APLP)] and resin composite (TPH-Spectrum) were bonded to the dentin (n = 8/group, 180 total specimens) under five surface conditions: control (adhesive applied following manufacturers’ instructions); saliva, then 5-s air dry, then adhesive; adhesive, saliva, 5-s air dry; adhesive, saliva, 5-s water rinse, 5-s air dry (ASW group); and adhesive, saliva, 5-s water rinse, 5-s air dry, reapply adhesive (ASWA group). After storage in water at 37°C for 24 h, the specimens were debonded under tension at a speed of 0.5 mm/min. ESEM photomicrographs of the dentin/adhesive interfaces were taken. Mean bond strength ranged from 8.1 to 24.1 MPa. Fisher’s protected least significant difference (P = 0.05) intervals for critical adhesive, saliva, and surface condition differences were 1.3, 1.3, and 2.1 MPa, respectively. There were no significant differences in bond strength to dentin between contamination by smoker’s and non-smoker’s saliva, but bond strengths were significantly different between adhesive systems, with OUFP twice as strong as APLP under almost all conditions. After adhesive application and contamination with either smoker’s or nonsmoker’s saliva followed by washing and reapplication of the adhesive (ASWA group), the bond strength of both adhesive systems was the same as that of the control group. PMID:20155506

  17. Shear bond strength and ultrastructural interface analysis of different adhesive systems to Er:YAG laser-prepared dentin.

    PubMed

    Guven, Yeliz; Aktoren, Oya

    2015-02-01

    The aim of this study was to evaluate the shear bond strength (SBS) of a microhybrid composite resin bonded with three different adhesive systems to Er:YAG laser- (EL) or bur-prepared dentin surfaces and to analyze the quality and ultrastructure of the adhesive-dentin interfaces by scanning electron microscopy (SEM). The specimens prepared for SBS test and SEM analysis were randomly assigned to eight groups (G1-G8): G1, EL (Fidelis PlusIII, Fotona) + Clearfil S3 Bond (C3S); G2, EL + AdperSE Plus (SE); G3, EL + laser etch + Adper Single Bond2 (SB2); G4, EL + acid etch + SB2; G5, EL + SB2 (no etching); G6, bur + acid etch + SB2; G7, bur + S3; G8, bur + SE. Laser was used in very short pulse mode at a setting of 200 mJ/20 Hz for dentin preparation and at 80 mJ/10 Hz for dentin etching. Bond strength test: 3.5 × 2.0 mm cylindrical molds were placed onto adhesives and filled with the composites. After 24 h in distilled water, SBS was tested at a crosshead speed of 0.5 mm/min. SEM analysis: The dentin-adhesive interfaces were evaluated for the ultrastructure of hybrid layer. Data of SBS (MPa) were statistically analyzed by ANOVA and Tukey HSD. ER:YAG laser-prepared dentin has demonstrated significantly more SBS (p < 0.01) for SE when compared to bur-prepared dentin. No significancies (p > 0.05) in SBS have been determined between the total-etch adhesive applied groups with regard to etching types. SEM analysis revealed that hybrid layers obtained in Er:YAG laser-irradiated dentin exhibited more irregular and non-homogeneous pattern than the conventionally prepared dentin. In conclusion, SE Bond demonstrated superior results in Er:YAG laser-ablated dentin compared to bur-prepared dentin. PMID:23982720

  18. Planar graphical models which are easy

    SciTech Connect

    Chertkov, Michael; Chernyak, Vladimir

    2009-01-01

    We describe a rich family of binary variables statistical mechanics models on planar graphs which are equivalent to Gaussian Grassmann Graphical models (free fermions). Calculation of partition function (weighted counting) in the models is easy (of polynomial complexity) as reduced to evaluation of determinants of matrixes linear in the number of variables. In particular, this family of models covers Holographic Algorithms of Valiant and extends on the Gauge Transformations discussed in our previous works.

  19. Bonds Boom.

    ERIC Educational Resources Information Center

    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 outlines…

  20. Yankee bonds

    SciTech Connect

    Delaney, P. )

    1993-10-01

    Yankee and Euromarket bonds may soon find their way into the financing of power projects in Latin America. For developers seeking long-term commitments under build, own, operate, and transfer (BOOT) power projects in Latin America, the benefits are substantial.

  1. Shear Bond Strengths of Methacrylate- and Silorane-based Composite Resins to Feldspathic Porcelain using Different Adhesive Systems.

    PubMed

    Mohammadi, Narmin; Shakur Shahabi, Maryam; Kimyai, Soodabeh; Pournagi Azar, Fatemeh; Ebrahimi Chaharom, Mohammad Esmaeel

    2015-01-01

    Background and aims. Use of porcelain as inlays, laminates and metal-ceramic and all-ceramic crowns is common in modern dentistry. The high cost of ceramic restorations, time limitations and difficulty of removing these restorations result in delays in replacing fractured restorations; therefore, their repair is indicated. The aim of the present study was to compare the shear bond strengths of two types of composite resins (methacrylate-based and silorane-based) to porcelain, using three adhesive types. Materials and methods. A total of 156 samples of feldspathic porcelain surfaces were prepared with air-abrasion and randomly divided into 6 groups (n=26). In groups 1-3, Z250 composite resin was used to repair porcelain samples with Ad-per Single Bond 2 (ASB), Clearfil SE Bond (CSB) and Silorane Adhesive (SA) as the bonding systems, afterapplication of silane, respectively. In groups 4-6, the same adhesives were used in the same manner with Filtek Silorane composite resin. Finally, the shear bond strengths of the samples were measured. Two-way ANOVA and post hoc Tukey tests were used to compare bond strengths between the groups with different adhesives at P<0.05. Results. There were significant differences in the mean bond strength values in terms of the adhesive type (P<0.001). In addition, the interactive effect of the adhesive type and composite resin type had no significant effect on bond strength (P=0.602). Conclusion. The results of the present study showed the highest repair bond strength values to porcelain with both composite resin types with the application of SA and ASB. PMID:26697151

  2. Shear Bond Strengths of Methacrylate- and Silorane-based Composite Resins to Feldspathic Porcelain using Different Adhesive Systems

    PubMed Central

    Mohammadi, Narmin; Shakur Shahabi, Maryam; Kimyai, Soodabeh; Pournagi Azar, Fatemeh; Ebrahimi Chaharom, Mohammad Esmaeel

    2015-01-01

    Background and aims. Use of porcelain as inlays, laminates and metal-ceramic and all-ceramic crowns is common in modern dentistry. The high cost of ceramic restorations, time limitations and difficulty of removing these restorations result in delays in replacing fractured restorations; therefore, their repair is indicated. The aim of the present study was to compare the shear bond strengths of two types of composite resins (methacrylate-based and silorane-based) to porcelain, using three adhesive types. Materials and methods. A total of 156 samples of feldspathic porcelain surfaces were prepared with air-abrasion and randomly divided into 6 groups (n=26). In groups 1-3, Z250 composite resin was used to repair porcelain samples with Ad-per Single Bond 2 (ASB), Clearfil SE Bond (CSB) and Silorane Adhesive (SA) as the bonding systems, afterapplication of silane, respectively. In groups 4-6, the same adhesives were used in the same manner with Filtek Silorane composite resin. Finally, the shear bond strengths of the samples were measured. Two-way ANOVA and post hoc Tukey tests were used to compare bond strengths between the groups with different adhesives at P<0.05. Results. There were significant differences in the mean bond strength values in terms of the adhesive type (P<0.001). In addition, the interactive effect of the adhesive type and composite resin type had no significant effect on bond strength (P=0.602). Conclusion. The results of the present study showed the highest repair bond strength values to porcelain with both composite resin types with the application of SA and ASB. PMID:26697151

  3. The use of warm air stream for solvent evaporation: effects on the durability of resin-dentin bonds.

    PubMed

    Reis, Alessandra; Klein-Júnior, Celso A; de Souza, Fabio H Coelho; Stanislawczuk, Rodrigo; Loguercio, Alessandro D

    2010-01-01

    This study evaluated the effect of a warm (W) or cold (C) air-dry stream for solvent evaporation on the immediate (IM) and six-month (6M) resin-dentin bond strength (microTBS) and silver nitrate uptake pattern (SNU) of two-step etch-and-rinse adhesive system (Adper Single Bond [SB] and Prime & Bond 2.1 [PB]). The adhesives were applied on demineralized dentin surfaces and a warm or cold air-dry stream (10 seconds) was applied followed by light-activation (10 seconds). After 24-hours of water storage, the specimens were serially sectioned in the "x" and "y" directions to obtain bonded sticks around 0.8 mm2 to be tested immediately or after six months of water storage. The specimens at each period were immersed in a 50% solution of silver nitrate, photodeveloped and analyzed by SEM for SNU. Higher IM microTBS values were observed for SB under W conditions. Both adhesives showed reductions in microTBS after 6M in both air temperatures. Regarding SEM, a low silver nitrate uptake was observed in the W groups either in IM or 6M for both adhesives. PMID:20166408

  4. Diffusion bonding

    DOEpatents

    Anderson, Robert C.

    1976-06-22

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

  5. An easy measure of quantum correlation

    NASA Astrophysics Data System (ADS)

    Cao, Hui; Wu, Zhao-Qin; Hu, Li-Yun; Xu, Xue-Xiang; Huang, Jie-Hui

    2015-11-01

    To measure the quantum correlation of a bipartite state, a test matrix is constructed through the commutations among the blocks of its density matrix, which turns out to be a zero matrix for a classical state with zero quantum correlation, and a nonzero one for a quantum state with positive quantum correlation. The Frobenius norm of the test matrix is used to measure the quantum correlation, which satisfies the basic requirements for a good measure and coincides with Wootters concurrence for two-qubit pure states. Since no optimization is involved in the definition, this measure of quantum correlation is easy to compute and even can be calculated manually.

  6. Planar graphical models which are easy

    NASA Astrophysics Data System (ADS)

    Chernyak, Vladimir Y.; Chertkov, Michael

    2010-11-01

    We describe a rich family of binary variables statistical mechanics models on a given planar graph which are equivalent to Gaussian Grassmann graphical models (free fermions) defined on the same graph. Calculation of the partition function (weighted counting) for such a model is easy (of polynomial complexity) as it is reducible to evaluation of a Pfaffian of a matrix of size equal to twice the number of edges in the graph. In particular, this approach touches upon holographic algorithms of Valiant and utilizes the gauge transformations discussed in our previous works.

  7. Chalcogen bond: a sister noncovalent bond to halogen bond.

    PubMed

    Wang, Weizhou; Ji, Baoming; Zhang, Yu

    2009-07-16

    A sister noncovalent bond to halogen bond, termed chalcogen bond, is defined in this article. By selecting the complexes H(2)CS...Cl(-), F(2)CS...Cl(-), OCS...Cl(-), and SCS...Cl(-) as models, the bond-length change, interaction energy, topological property of the electron charge density and its Laplacian, and the charge transfer of the chalcogen bond have been investigated in detail theoretically. It was found that the similar misshaped electron clouds of the chalcogen atom and the halogen atom result in the similar properties of the chalcogen bond and the halogen bond. Experimental results are in good agreement with the theoretical predictions.

  8. The effect of various primers on shear bond strength of zirconia ceramic and resin composite

    PubMed Central

    Sanohkan, Sasiwimol; Kukiattrakoon, Boonlert; Larpboonphol, Narongrit; Sae-Yib, Taewalit; Jampa, Thibet; Manoppan, Satawat

    2013-01-01

    Aims: To determine the in vitro shear bond strengths (SBS) of zirconia ceramic to resin composite after various primer treatments. Materials and Methods: Forty zirconia ceramic (Zeno, Wieland Dental) specimens (10 mm in diameter and 2 mm thick) were prepared, sandblasted with 50 μm alumina, and divided into four groups (n = 10). Three experimental groups were surface treated with three primers; CP (RelyX Ceramic Primer, 3M ESPE), AP (Alloy Primer, Kuraray Medical), and MP (Monobond Plus, Ivoclar Vivadent AG). One group was not treated and served as the control. All specimens were bonded to a resin composite (Filtek Supreme XT, 3M ESPE) cylinder with an adhesive system (Adper Scotchbond Multi-Purpose Plus Adhesive, 3M ESPE) and then stored in 100% humidity at 37°C for 24 h before SBS testing in a universal testing machine. Mean SBS (MPa) were analyzed with one-way analysis of variance (ANOVA) and the Tukey's Honestly Significant Difference (HSD) test (α = 0.05). Results: Group AP yielded the highest mean and standard deviation (SD) value of SBS (16.8 ± 2.5 MPa) and Group C presented the lowest mean and SD value (15.4 ± 1.6 MPa). The SBS did not differ significantly among the groups (P = 0.079). Conclusions: Within the limitations of this study, the SBS values between zirconia ceramic to resin composite using various primers and untreated surface were not significantly different. PMID:24347881

  9. Pi Bond Orders and Bond Lengths

    ERIC Educational Resources Information Center

    Herndon, William C.; Parkanyi, Cyril

    1976-01-01

    Discusses three methods of correlating bond orders and bond lengths in unsaturated hydrocarbons: the Pauling theory, the Huckel molecular orbital technique, and self-consistent-field techniques. (MLH)

  10. Erosive cola-based drinks affect the bonding to enamel surface: an in vitro study

    PubMed Central

    CASAS-APAYCO, Leslie Caroll; DREIBI, Vanessa Manzini; HIPÓLITO, Ana Carolina; GRAEFF, Márcia Sirlene Zardin; RIOS, Daniela; MAGALHÃES, Ana Carolina; BUZALAF, Marília Afonso Rabelo; WANG, Linda

    2014-01-01

    Objective This study aimed to assess the impact of in vitro erosion provoked by different cola-based drinks (Coke types), associated or not with toothbrushing, to bonding to enamel. Material and Methods Fifty-six bovine enamel specimens were prepared and randomly assigned into seven groups (N=8): C- Control (neither eroded nor abraded), ERO-RC: 3x/1-minute immersion in Regular Coke (RC), ERO-LC: 3x/1-minute immersion in Light Coke (LC), ERO-ZC: 3x/1-minute immersion in Zero Coke (ZC) and three other eroded groups, subsequently abraded for 1-minute toothbrushing (EROAB-RC, EROAB-LC and EROAB-ZC, respectively). After challenges, they were stored overnight in artificial saliva for a total of 24 hours and restored with Adper Single Bond 2/Filtek Z350. Buildup coronal surfaces were cut in 1 mm2 -specimens and subjected to a microtensile test. Data were statistically analyzed by two-way ANOVA/Bonferroni tests (α=0.05). Failure modes were assessed by optical microscopy (X40). The interface of the restorations were observed using Confocal Laser Scanning Microscopy (CLSM). Results All tested cola-based drinks significantly reduced the bond strength, which was also observed in the analyses of interfaces. Toothbrushing did not have any impact on the bond strength. CLSM showed that except for Zero Coke, all eroded specimens resulted in irregular hybrid layer formation. Conclusions All cola-based drinks reduced the bond strength. Different patterns of hybrid layers were obtained revealing their impact, except for ZC. PMID:24918663

  11. Can green tea be used to reverse compromised bond strength after bleaching?

    PubMed

    Berger, Sandrine B; De Souza Carreira, Renata P; Guiraldo, Ricardo D; Lopes, Murilo B; Pavan, Sabrina; Giannini, Marcelo; Bedran-Russo, Ana K

    2013-08-01

    The objective of this study was to evaluate the antioxidant effect of green tea on microtensile bond strength (μTBS) to bleached enamel. Forty-two human third molars were randomly divided into six experimental groups (n = 7 each group): group 1, no treatment; group 2, bleaching (10% carbamide peroxide); group 3, bleaching + 10% sodium ascorbate gel (SA); group 4, bleaching + 10% green tea gel (GT); group 5, SA; and group 6, GT. In groups 2, 3, and 4, bleach was applied onto the enamel surface for 6 h, every day for 14 d. In groups 3 and 5, SA was applied for 1 h; and in groups 4 and 6, GT was applied for 1 h. Immediately after treatment, the specimens were bonded with Adper Single Bond 2 and Filtek Z350 XT. The μTBS of the specimens was tested using a universal testing machine. Fracture mode analysis of the bonded enamel surface was performed using scanning electron microscopy. The mean μTBS values for each group were: group 1, 33.2 ± 5.8 MPa; group 2, 22.6 ± 5.5 MPa; group 3, 30.0 ± 5.2 MPa; group 4, 31.6 ± 3.8 MPa; group 5, 29.1 ± 4.2 MPa; and group 6, 32.2 ± 4.5 MPa. All groups had a higher percentage of mixed failures. In conclusion, green tea can be used as an alternative antioxidant on bleached enamel before bonding procedures. PMID:23841791

  12. EASI: An electronic assistant for scientific investigation

    SciTech Connect

    Schur, A.; Feller, D.; DeVaney, M.; Thomas, J.; Yim, M.

    1991-09-01

    Although many automated tools support the productivity of professionals (engineers, managers, architects, secretaries, etc.), none specifically address the needs of the scientific researcher. The scientist's needs are complex and the primary activities are cognitive rather than physical. The individual scientist collects and manipulates large data sets, integrates, synthesizes, generates, and records information. The means to access and manipulate information are a critical determinant of the performance of the system as a whole. One hindrance in this process is the scientist's computer environment, which has changed little in the last two decades. Extensive time and effort is demanded from the scientist to learn to use the computer system. This paper describes how chemists' activities and interactions with information were abstracted into a common paradigm that meets the critical requirement of facilitating information access and retrieval. This paradigm was embodied in EASI, a working prototype that increased the productivity of the individual scientific researcher. 4 refs., 2 figs., 1 tab.

  13. Bonded Lubricants

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Another spinoff to the food processing industry involves a dry lubricant developed by General Magnaplate Corp. of Linden, N.J. Used in such spacecraft as Apollo, Skylab and Viking, the lubricant is a coating bonded to metal surfaces providing permanent lubrication and corrosion resistance. The coating lengthens equipment life and permits machinery to be operated at greater speed, thus increasing productivity and reducing costs. Bonded lubricants are used in scores of commercia1 applications. They have proved particularly valuable to food processing firms because, while increasing production efficiency, they also help meet the stringent USDA sanitation codes for food-handling equipment. For example, a cookie manufacturer plagued production interruptions because sticky batter was clogging the cookie molds had the brass molds coated to solve the problem. Similarly, a pasta producer faced USDA action on a sanitation violation because dough was clinging to an automatic ravioli-forming machine; use of the anti-stick coating on the steel forming plates solved the dual problem of sanitation deficiency and production line downtime.

  14. Effect of indirect composite treatment microtensile bond strength of self-adhesive resin cements

    PubMed Central

    Escribano, Nuria; Baracco, Bruno; Romero, Martin; Ceballos, Laura

    2016-01-01

    Background No specific indications about the pre-treatment of indirect composite restorations is provided by the manufacturers of most self-adhesive resin cements. The potential effect of silane treatment to the bond strength of the complete tooth/indirect restoration complex is not available.The aim of this study was to determine the contribution of different surface treatments on microtensile bond strength of composite overlays to dentin using several self-adhesive resin cements and a total-etch one. Material and Methods Composite overlays were fabricated and bonding surfaces were airborne-particle abraded and randomly assigned to two different surface treatments: no treatment or silane application (RelyX Ceramic Primer) followed by an adhesive (Adper Scotchbond 1 XT). Composite overlays were luted to flat dentin surfaces using the following self-adhesive resin cements: RelyX Unicem, G-Cem, Speedcem, Maxcem Elite or Smartcem2, and the total-etch resin cement RelyX ARC. After 24 h, bonded specimens were cut into sticks 1 mm thick and stressed in tension until failure. Two-way ANOVA and SNK tests were applied at α=0.05. Results Bond strength values were significantly influenced by the resin cement used (p<0.001). However, composite surface treatment and the interaction between the resin cement applied and surface treatment did not significantly affect dentin bond strength (p>0.05). All self-adhesive resin cements showed lower bond strength values than the total-etch RelyX ARC. Among self-adhesive resin cements, RelyX Unicem and G-Cem attained statistically higher bond strength values. Smartcem2 and Maxcem Elite exhibited 80-90% of pre-test failures. Conclusions The silane and adhesive application after indirect resin composite sandblasting did not improve the bond strength of dentin-composite overlay complex. Selection of the resin cement seems to be a more relevant factor when bonding indirect composites to dentin than its surface treatment. Key words:Bond

  15. Easy on the Mind, Easy on the Wrongdoer: Discrepantly Fluent Violations Are Deemed Less Morally Wrong

    ERIC Educational Resources Information Center

    Laham, Simon M.; Alter, Adam L.; Goodwin, Geoffrey P.

    2009-01-01

    The present experiment tested the hypothesis that discrepancies in processing fluency influence the perceived wrongness of moral violations. Participants were presented with numerous moral violations in easy or difficult to read fonts. For some violations, experienced perceptual fluency was consistent with the fluency associated with previous…

  16. Influence of casein phosphopeptide-amorphous calcium phosphate application, smear layer removal, and storage time on resin-dentin bonding*

    PubMed Central

    Lin, Jun; Zheng, Wei-ying; Liu, Peng-ruo-feng; Zhang, Ning; Lin, Hui-ping; Fan, Yi-jing; Gu, Xin-hua; Vollrath, Oliver; Mehl, Christian

    2014-01-01

    The aim of this study is to evaluate the influence of Tooth Mousse (TM) application, smear layer removal, and storage time on resin-dentin microtensile bond strength (μTBS). Dentin specimens were divided into two groups: (1) smear layer covered; (2) smear layer removed using 15% EDTA for 90 s. In each group, half the specimens were treated once with TM for 60 min. After bonding procedures using a two-step self-etching adhesive (Clearfil SE Bond (CSE); Kuraray Medical, Tokyo, Japan), an all-in-one adhesive (G-Bond (GB); GC Corp, Tokyo, Japan), and a total-etch adhesive (Adper Single Bond 2 (SB); 3M ESPE, St. Paul, MN, USA), the specimens were stored for 3 d or 6 months in deionized water at 37 °C, and μTBS was tested and analyzed. With the exception of SB (no TM application) and GB, the μTBS was significantly increased for CSE and SB using EDTA pre-conditioning and 3 d of storage (P≤0.001). Bond strength of GB decreased significantly when using EDTA (3 d storage, P<0.05). TM application only increased the μTBS of GB (no EDTA) and SB (with EDTA) after 3 d (P≤0.02). Comparing the adhesives after 3 d of storage, CSE exhibited the greatest μTBS values followed by GB and SB (P≤0.02). The factors of adhesive, EDTA, and TM did not show any significant impact on μTBS when specimens were stored for 6 months (P>0.05). The additional application of TM and EDTA for cavity preparation seems only to have a short-term effect, and no influence on μTBS of dentin bonds after a period of 6 months. PMID:25001224

  17. 76 FR 3679 - Market Test of Marketing Mail Made Easy

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-20

    ... Market Test of Marketing Mail Made Easy AGENCY: Postal Regulatory Commission. ACTION: Notice. SUMMARY... involving the sale of Marketing Mail Made Easy. This document describes the proposed test, addresses... experimental market dominant product, Marketing Mail Made Easy (MMME).\\1\\ The market test will begin on...

  18. Casein Phosphopeptide-Amorphous Calcium Phosphate and Shear Bond Strength of Adhesives to Primary Teeth Enamel

    PubMed Central

    Farokh Gisovar, Elham; Hedayati, Nassim; Shadman, Niloofar; Shafiee, Leila

    2015-01-01

    Background: CPP-ACP (Phosphopeptide-Amorphous Calcium Phosphate) has an important role in caries prevention in pediatric patients. This study was done, because of the great use of CPP-ACP and the need for restoration for teeth treated with CPP-ACP as well as the importance of shear bond strength of adhesives in the success of restorations. Objectives: This study aimed to evaluate the effect of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on shear bond strength of dental adhesives to enamel of primary teeth molars. Materials and Methods: This in vitro study was conducted on 180 extracted primary molars. They were randomly divided into 6 groups and each group was divided into 2 subgroups (treated with CPP-ACP and untreated). In subgroups with CPP-ACP, enamel was treated with CPP-ACP paste 1 h/d for 5 days. Types of adhesives that were evaluated in this study were Tetric N-Bond, AdheSE, AdheSE One F, single Bond 2, SE Bond, and Adper Prompt L-Pop. Shear bond strength was tested with a universal testing machine and mode of failure was evaluated under stereomicroscope. Data were analyzed by T test, 2-way analysis of variance (ANOVA), Tukey and Fisher exact test using SPSS18. P < 0.05 was considered as significance level. Results: Shear bond strengths of different adhesive systems to enamel of primary teeth treated and untreated with CPP-ACP showed no significant difference (P > 0.05). Mode of failure in all groups regardless of CPP-ACP administration was mainly adhesive type. Our results indicated that CPP-ACP did not affect shear bond strength of studied adhesives to primary teeth enamel. Conclusions: To have a successful and durable composite restoration, having a high strength bonding is essential. Considering the wide use of CPP-ACP in preventing tooth decay and the role of adhesive shear bond strength (SBS) in success of composite restoration, we conducted the present study to evaluate the effect of CPP-ACP on the SBS of adhesives to primary teeth

  19. Easy system call tracing for Plan 9.

    SciTech Connect

    Minnich, Ronald G.

    2010-09-01

    Tracing system calls makes debugging easy and fast. On Plan 9, traditionally, system call tracing has been implemented with acid. New systems do not always implement all the capabilities needed for Acid, particularly the ability to rewrite the process code space to insert breakpoints. Architecture support libraries are not always available for Acid, or may not work even on a supported architecture. The requirement that Acid's libraries be available can be a problem on systems with a very small memory footprint, such as High Performance Computing systems where every Kbyte counts. Finally, Acid tracing is inconvenient in the presence of forks, which means tracing shell pipelines is particularly troublesome. The strace program available on most Unix systems is far more convenient to use and more capable than Acid for system call tracing. A similar system on Plan 9 can simplify troubleshooting. We have built a system calling tracing capability into the Plan 9 kernel. It has proven to be more convenient than strace in programming effort. One can write a shell script to implement tracing, and the C code to implement an strace equivalent is several orders of magnitude smaller.

  20. Visualization of Large Terrains Made Easy

    SciTech Connect

    Lindstrom, P; Pascucci, V

    2001-08-07

    We present an elegant and simple to implement framework for performing out-of-core visualization and view-dependent refinement of large terrain surfaces. Contrary to the recent trend of increasingly elaborate algorithms for large-scale terrain visualization, our algorithms and data structures have been designed with the primary goal of simplicity and efficiency of implementation. Our approach to managing large terrain data also departs from more conventional strategies based on data tiling. Rather than emphasizing how to segment and efficiently bring data in and out of memory, we focus on the manner in which the data is laid out to achieve good memory coherency for data accesses made in a top-down (coarse-to-fine) refinement of the terrain. We present and compare the results of using several different data indexing schemes, and propose a simple to compute index that yields substantial improvements in locality and speed over more commonly used data layouts. Our second contribution is a new and simple, yet easy to generalize method for view-dependent refinement. Similar to several published methods in this area, we use longest edge bisection in a top-down traversal of the mesh hierarchy to produce a continuous surface with subdivision connectivity. In tandem with the refinement, we perform view frustum culling and triangle stripping. These three components are done together in a single pass over the mesh. We show how this framework supports virtually any error metric, while still being highly memory and compute efficient.

  1. Influence of Surface Treatments and Adhesive Systems on Lithium Disilicate Microshear Bond Strength.

    PubMed

    Garboza, Celso Sebastião; Berger, Sandrine Bittencourt; Guiraldo, Ricardo Danil; Fugolin, Ana Paula Piovezan; Gonini-Júnior, Alcides; Moura, Sandra Kiss; Lopes, Murilo Baena

    2016-01-01

    The purpose of this study was to evaluate the microshear bond strength of ceramic prosthetic structures reinforced by lithium disilicate cemented with resin cement under conditions of different surface treatments and adhesive systems. Seventy-two rectangular blocks of lithium disilicate (6.5 mm long × 5 mm wide × 1 mm thick) were fabricated, air abraded with 50-μm Al2O3 particles and divided into six groups (n=12) depending on the surface pretreatments. The groups were as follows: 10HF/S/SBM: 10% hydrofluoric acid etched for 20 s (10HF) + silane (S) + Adper Scotchbond Multi-Purpose (SBM); 10HF/S/SB: 10HF + S + Single Bond Universal (SB); 10HF/SBM; 10HF/SB; S/SBM and S/SB. Two 1-mm-long plastic tubes were placed on the specimens, filled with RelyX ARC resin cement and cured for 20 s per tube. The plastic tube was removed, and the microshear bond strength was tested. Data were submitted to analysis of variance and Tukey's tests (α=0.05). Fractured specimens were observed under optical microscopy. For both adhesives, the bond strengths (MPa) of groups treated with acid-etching and silane (10HF/S/SB: 24.82, 10HF/S/SBM: 24.90) were higher (p<0.001) than those of groups treated with acid-etching (10HF/SB: 16.47, 10HF/SBM: 19.94) only or only silane (S/SB: 18.42, S/SBM: 13.24). All groups showed a predominance of failure adhesive. The silanization should be a clinical step in cementing ceramic structures reinforced by lithium disilicate, even with the application of universal adhesive that contains silane in its formulation. PMID:27652711

  2. Effect of Adhesive Cementation Strategies on the Bonding of Y-TZP to Human Dentin.

    PubMed

    Alves, Mll; Campos, F; Bergoli, C D; Bottino, M A; Özcan, M; Souza, Roa

    2016-01-01

    This study evaluated the effects of different adhesive strategies on the adhesion of zirconia to dentin using conventional and self-adhesive cements and their corresponding adhesive resins. The occlusal parts of human molars (N=80) were sectioned, exposing the dentin. The teeth and zirconia cylinders (N=80) (diameter=3.4 mm; height=4 mm) were randomly divided into eight groups according to the factors "surface conditioning" and "cement type" (n=10 per group). One conventional cement (CC: RelyX ARC, 3M ESPE) and one self-adhesive cement (SA: RelyX U200, 3M ESPE) and their corresponding adhesive resin (for CC, Adper Single Bond Plus; for SA, Scotchbond Universal Adhesive-SU) were applied on dentin. Zirconia specimens were conditioned either using chairside (CJ: CoJet, 30 μm, 2.5 bar, four seconds), laboratory silica coating (RC: Rocatec, 110 μm, 2.5 bar, four seconds), or universal primer (Single Bond Universal-UP). Nonconditioned groups for both cements acted as the control (C). Specimens were stored in water (37°C, 30 days) and subjected to shear bond strength (SBS) testing (1 mm/min). Data (MPa) were analyzed using two-way analysis of variance and a Tukey test (α=0.05). While surface conditioning significantly affected the SBS values (p=0.0001) (Cbond strength of zirconia to dentin compared to the control group, regardless of the type of resin cement used.

  3. Shear bond strength of bulk-fill and nano-restorative materials to dentin

    PubMed Central

    Colak, Hakan; Ercan, Ertugrul; Hamidi, Mehmet Mustafa

    2016-01-01

    Objectives: Bulk-fill composite materials are being developed for preparation depths of up to 4 mm in an effort to simplify and improve the placement of direct composite posterior restorations. The aim of our study was to compare shear-bond strength of bulk-fill and conventional posterior composite resins. Materials and Methods: In this study, 60 caries free extracted human molars were used and sectioned parallel to occlusal surface to expose midcoronal dentin. The specimens were randomly divided into four groups. Total-etch dentine bonding system (Adper Scotchbond 1XT, 3M ESPE) was applied to dentin surface in all the groups to reduce variability in results. Then, dentine surfaces covered by following materials. Group I: SonicFill Bulk-Fill, Group II: Tetric EvoCeram (TBF), Group III: Herculite XRV Ultra, and Group IV: TBF Bulk-Fill, 2 mm × 3 mm cylindrical restorations were prepared by using application apparatus. Shear bond testing was measured by using a universal testing machine. Kruskal–Wallis and Mann–Whitney U-tests were performed to evaluate the data. Results: The highest value was observed in Group III (14.42 ± 4.34) and the lowest value was observed in Group IV (11.16 ± 2.76) and there is a statistically significant difference between these groups (P = 0.046). However, there is no statistically significant difference between the values of other groups. In this study, Group III was showed higher strength values. Conclusion: There is a need for future studies about long-term bond strength and clinical success of these adhesive and bulk-fill systems. PMID:27011738

  4. Easy to write? Creating easy-to-read patient education materials.

    PubMed

    Karten, Clare

    2007-08-01

    The Leukemia & Lymphoma Society develops and distributes both detailed and easy-to-read booklets intended to help patients and caregivers communicate with healthcare providers about their treatment and support needs. The easy-to-read booklets initially were developed for newly diagnosed patients; however, the society has learned that all patients with cancer are likely to benefit from the information at some point in their journeys. To date, the society has developed easy-to-read booklets about acute lymphocytic leukemia, acute myelogenous leukemia, chronic lymphocytic leukemia, chronic myelogenous leukemia, lymphomas, myeloma, and coping with blood cancer. All booklets are free to patients, healthcare providers, and the general public, and most titles are available in Spanish-language versions. They can be ordered through the society's Information Resource Center (800-955-4572, infocenter@lls.org, or www.lls.org) or its 68 chapters. This article focuses on the development of the booklet Myeloma: A Guide for Patients and Caregivers and includes a handout based on its content.

  5. EZID: Long term identifiers made easy (Invited)

    NASA Astrophysics Data System (ADS)

    Starr, J.

    2013-12-01

    Scholarly research is producing ever increasing amounts of digital research data, and this data should be managed throughout the research life cycle both as part of good scientific practice, but also to comply with funder mandates, such as the 2013 OSTP Public Access Memo (http://www.whitehouse.gov/sites/default/files/microsites/ostp/ostp_public_access_memo_2013.pdf). By assigning unique and persistent identifiers to data objects, data managers can gain control and flexibility over what can be a daunting task. This is due to the fact that the objects can be moved to new locations without disruption to links, as long as the identifier target is maintained. EZID is a tool that makes assigning and maintaining unique, persistent identifiers easy. It was designed and built by California Digital Library (CDL) and has both a user interface and a RESTful API. EZID currently offers services for two globally unique, persistent identifier schemes: Digital Object Identifiers (DOIs) and Archival Resource Keys (ARKs). DOIs are identifiers originating from the publishing world and are in widespread use for journal articles. CDL is able to offer DOIs because of being a founding member of DataCite (http://www.datacite.org/), an international consortium established to provide easier access to scientific research data on the Internet. ARKs are identifiers originating from the library, archive and museum community. Like DOIs, they become persistent when the objects and identifier forwarding information is maintained. DOIs and ARKs have a key role in data management and, therefore, in data management plans. DOIs are the recommended identifier for use in data citation, and ARKs provide the maximum flexibility needed for data documentation and management throughout the early phases of a project. The two identifier schemes are able to be used together, and EZID is made to work with both. EZID clients, coming from education, research, government, and the private sector, are utilizing the

  6. Effect of EDTA and Phosphoric Acid Pretreatment on the Bonding Effectiveness of Self-Etch Adhesives to Ground Enamel

    PubMed Central

    Ibrahim, Ihab M.; Elkassas, Dina W.; Yousry, Mai M.

    2010-01-01

    Objectives: This in vitro study determined the effect of enamel pretreatment with phosphoric acid and ethylenediaminetetraacetic acid (EDTA) on the bond strength of strong, intermediary strong, and mild self-etching adhesive systems. Methods: Ninety sound human premolars were used. Resin composite cylinders were bonded to flat ground enamel surfaces using three self-etching adhesive systems: strong Adper Prompt L-Pop (pH=0.9–1.0), intermediary strong AdheSE (pH=1.6–1.7), and mild Frog (pH=2). Adhesive systems were applied either according to manufacturer instructions (control) or after pretreatment with either phosphoric acid or EDTA (n=10). After 24 hours, shear bond strength was tested using a universal testing machine at a cross-head speed of 0.5 mm/minute. Ultra-morphological characterization of the surface topography and resin/enamel interfaces as well as representative fractured enamel specimens were examined using scanning electron microscopy (SEM). Results: Neither surface pretreatment statistically increased the mean shear bond strength values of either the strong or the intermediary strong self-etching adhesive systems. However, phosphoric acid pretreatment significantly increased the mean shear bond strength values of the mild self-etching adhesive system. SEM examination of enamel surface topography showed that phosphoric acid pretreatment deepened the same etching pattern of the strong and intermediary strong adhesive systems but converted the irregular etching pattern of the mild self-etching adhesive system to a regular etching pattern. SEM examination of the resin/enamel interface revealed that deepening of the etching pattern was consistent with increase in the length of resin tags. EDTA pretreatment had a negligible effect on ultra-morphological features. Conclusions: Use of phosphoric acid pretreatment can be beneficial with mild self-etching adhesive systems for bonding to enamel. PMID:20922162

  7. Effect of Pre-heating on Microtensile Bond Strength of Composite Resin to Dentin

    PubMed Central

    Davari, Abdolrahim; Daneshkazemi, Alireza; Behniafar, Behnaz; Sheshmani, Mahsan

    2014-01-01

    Objective: Direct composite resin restorations are widely used and the impact of different storage temperatures on composites is not well understood. The purpose of this study was to evaluate the microtensile bond strength of composite to dentin after different pre-curing temperatures. Materials and Methods: Occlusal surfaces of 44 human molars were ground with diamond burs under water coolant and polished with 600 grit silicon carbide papers to obtain flat dentin surfaces. The dentin was etched with 37% phosphoric acid and bonded with Adper Single Bond 2 according to the manufacturer's instructions. The specimens were randomly divided into two groups (n=22) according to the composite resin applied: FiltekP60 and Filtek Z250. Each group included three subgroups of composite resin pre-curing temperatures (4°C, 23°C and 37°C). Composite resins were applied to the dentin surfaces in a plastic mold (8mm in diameter and 4mm in length) incrementally and cured. Twenty-two composite-to-dentin hour-glass sticks with one mm2 cross-sectional area per group were prepared. Microtensile bond strength measurements were made using a universal testing machine at a crosshead speed of one mm/min. For statistical analysis, t-test, one-way and two-way ANOVA were used. The level of significance was set at P<0.05. Results: Filtek P60 pre-heated at 37ºC had significantly higher microtensile bond strength than Filtek Z250 under the same condition. The microtensile bond strengths were not significantly different at 4ºC, 23ºC and 37ºC subgroups of each composite resin group. Conclusion: Filtek P60 and Filtek Z250 did not have significantly different microtensile bond strengths at 4ºC and 23ºC but Filtek P60 had significantly higher microtensile bond strength at 37 ºC. Composite and temperature interactions had significant effects on the bond strength. PMID:25628684

  8. Kinetics of pulpal temperature rise during light curing of 6 bonding agents from different generations, using light emitting diode and quartz-tungsten-halogen units: An in-vitro simulation

    PubMed Central

    Khaksaran, Najmeh Khatoon; Kashi, Tahereh Jafarzadeh; Rakhshan, Vahid; Zeynolabedin, Zahra Sadat; Bagheri, Hossein

    2015-01-01

    Background: Application of bonding agents (BA) into deep cavities and light curing them might increase pulpal temperature and threaten its health. The purpose of this study was to evaluate temperature rise of pulp by light curing six BA using two different light curing units (LCU), through a dent in wall of 0.5 mm. Materials and Methods: This in vitro experiment was carried out on 96 slices of the same number of human third molars (6 BAs × 2 LCUs × 8 specimens in each group). There were 6 groups of BAs: N Bond, G-Bond, OptiBond XTR, Clearfil SE, Adper Single Bond 2 and V Bond. Each group of BA (n = 16) had two subgroups of light emitting diode (LED) and quartz-tungsten-halogen light cure units (n = 8). Each of these 16 specimens were subjected to light emitting for 20 s, once without any BAs (control) and later when a BA was applied to surface of disk. Temperature rises in 140 s were evaluated. Their mean temperature change in first 20 s were calculated and analyzed using two-way repeated-measures and one-way analysis of variance (ANOVA) and Tukey (α = 0.05). Furthermore rate of temperature increase was calculated for each material and LCU. Results: Minimum and maximum temperature rises in all subgroups were 1.7 and 2.8°C, respectively. Repeated measures ANOVA showed that both of adhesive and LCU types had significant effect on temperature rise after application of adhesives. Tukey post-hoc analysis showed Clearfil SE showed significantly higher temperature rise in comparison with Adper Single bond 2 (P = 0.047) and N Bond (P = 0.038). Temperature rose in a linear fashion during first 30-40 s and after that it was non-linear. Conclusion: 20 s of light curing seems safe for pulpal health (with critical threshold of 5.5°C). However, in longer durations and especially when using LED units, the process should be broken to two sessions. PMID:25878684

  9. Deconfined criticality in ``easy-plane'' SU(N) anti-ferromagnets

    NASA Astrophysics Data System (ADS)

    D'Emidio, Jonathan; Murthy, Ganpathy; Kaul, Ribhu

    Motivated by evidence for deconfined criticality in SU(N) anti-ferromagnets, we investigate the phase diagram of these models in the case where the SU(N) symmetry is reduced to rotations about the diagonal generators (''easy-plane'' symmetry). We carry out extensive numerical simulations using quantum Monte Carlo, revealing a first-order magnetic to valence bond solid phase transition that becomes a continuous deconfined transition at large N. We support our numerical data by performing epsilon expansions of the easy-plane deformed CP N - 1 field theory near both the upper and lower critical dimensions. This renormalization group analysis shows that the symmetric deconfined fixed point is unstable in the presence of easy-plane anisotropy, resulting in a runaway flow for intermediate values of N and a flow towards a stable easy-plane deconfined fixed point at large N, which is consistent with the critical behavior of our lattice models. This research was partially financially supported by NSF DMR-1056536.

  10. Chemical Bonds II

    ERIC Educational Resources Information Center

    Sanderson, R. T.

    1972-01-01

    The continuation of a paper discussing chemical bonding from a bond energy viewpoint, with a number of examples of single and multiple bonds. (Part I appeared in volume 1 number 3, pages 16-23, February 1972.) (AL)

  11. What Determines Bond Costs. Municipal Bonds Series.

    ERIC Educational Resources Information Center

    Young, Douglas; And Others

    Public officials in small towns who participate infrequently in the bond market need information about bond financing. This publication, one in a series of booklets published by the Western Rural Development Center using research gathered between 1967-77, discusses factors influencing the marketability and cost of bond financing for towns and…

  12. Hydrogen Bond Nanoscale Networks Showing Switchable Transport Performance

    NASA Astrophysics Data System (ADS)

    Long, Yong; Hui, Jun-Feng; Wang, Peng-Peng; Xiang, Guo-Lei; Xu, Biao; Hu, Shi; Zhu, Wan-Cheng; Lü, Xing-Qiang; Zhuang, Jing; Wang, Xun

    2012-08-01

    Hydrogen bond is a typical noncovalent bond with its strength only one-tenth of a general covalent bond. Because of its easiness to fracture and re-formation, materials based on hydrogen bonds can enable a reversible behavior in their assembly and other properties, which supplies advantages in fabrication and recyclability. In this paper, hydrogen bond nanoscale networks have been utilized to separate water and oil in macroscale. This is realized upon using nanowire macro-membranes with pore sizes ~tens of nanometers, which can form hydrogen bonds with the water molecules on the surfaces. It is also found that the gradual replacement of the water by ethanol molecules can endow this film tunable transport properties. It is proposed that a hydrogen bond network in the membrane is responsible for this switching effect. Significant application potential is demonstrated by the successful separation of oil and water, especially in the emulsion forms.

  13. One-year water sorption and solubility of "all-in-one" adhesives.

    PubMed

    Walter, Ricardo; Feiring, Andrew E; Boushell, Lee W; Braswell, Krista; Bartholomew, Whitley; Chung, Yunro; Phillips, Ceib; Pereira, Patricia N R; Swift, Edward J

    2013-01-01

    The aim of this study was to evaluate the water sorption and solubility of different adhesives. Adper Easy Bond, Adper Single Bond Plus, Bond Force, Clearfil SE Bond (bonding resin only), and Xeno IV were the materials evaluated. Ten disks of each adhesive were made in Teflon molds and evaporation of any volatile components was allowed. The disks were weighed daily in an analytical balance until a constant mass was obtained (m1). Disks were then immersed in water for 12 months when their wet weight was recorded (m2). The disks were again weighed daily until a constant mass was obtained and the final weight recorded (m3). Water sorption and solubility (percentages) were calculated using the recorded mass values. Kruskal-Wallis tests were used to compare the average water sorption and solubility among the different adhesives. Mann-Whitney tests with a Bonferroni correction were used to determine the pairwise differences between adhesives in water sorption and solubility. The level of significance was set at 0.05. Water sorption and solubility were significantly different among the groups (p<0.05). Pairwise comparisons showed no significant differences (p>0.05) between Adper Single Bond Plus and Bond Force, or between Clearfil SE Bond and Xeno IV in either water sorption or solubility. Xeno IV did not differ from Adper Easy Bond in water sorption (p>0.05). Water sorption and solubility of all-in-one adhesives increased with time, and the rates of increase were composition-dependent. The results suggest that monomers other than HEMA contribute to water sorption and solubility of adhesive systems from different categories. PMID:24173253

  14. Bond strength of an adhesive system irradiated with Nd:YAG laser in dentin treated with Er:YAG laser

    NASA Astrophysics Data System (ADS)

    Malta, D. A. M. P.; Costa, M. M.; Pelino, J. E. P.; de Andrade, M. F.; Lizarelli, R. F. Z.

    2008-02-01

    The purpose of this in vitro study was to verify through micro tensile bond test the bond strength of an adhesive system irradiated with Nd:YAG laser in dentine previously treated with Er:YAG laser. Twenty caries free extracted human third molars were used. The teeth were divided in four experimental groups (n = 5): (G1) control group; (G2) irradiation of the adhesive system with the Nd:YAG laser; (G3) dentin treatment with Er:YAG laser; (G4) dentin treatment with Er:YAG laser followed by the irradiation of the adhesive system with Nd:YAG laser. The Er:YAG laser fluency parameter for the dentin treatment was of 60 J/cm2. The adhesive system was irradiated with the Nd:YAG laser with fluency of 100 J/cm2. Dental restorations were performed with Adper Single Bond 2/Z250. One tooth from each group was prepared for the evaluation of the adhesive interface under SEM and bond failure tests were also performed and evaluated. The statistical analysis showed statistical significant difference between the groups G1 and G3, G1 and G4, G2 and G3, and G2 and G4; and similarity between the groups G1 and G2, and G3 and G4. The adhesive failures were predominant in all the experimental groups. The SEM analysis showed an adhesive interface with features confirming the results of the mechanical tests. The Nd:YAG laser on the adhesive system did not influence the bond strength in dentin treated or not with the Er:YAG laser.

  15. 24% Indigenously Prepared Ethylene Diamine Tetra Acetic Acid Compared to Self-Etching Adhesives and their Effect on Shear Bond Strength of Composites in Primary Teeth: An In-vitro Study

    PubMed Central

    Nagar, Priya; Tandil, Yogesh L.; T.P., Chandru; Gupta, Anamika; Kalaria, Devendra; Kumar, Prafful

    2015-01-01

    Background: Over the years, it has been known that 34% phosphoric acid is the benchmark in etchants with the best shear bond strength shown with composites in primary teeth. However, with latest technological advancements and innovations, in order to reduce the number of steps and less damage to the tooth structure, non-rinse conditioner (NRC) & Single-Etch and various other etchants have been tried and tested. These etchants have been found to have shear bond strength comparable to phosphoric acid. In this study, indigenously prepared 24% ethylenediaminetetraacetic acid (EDTA) has been compared with established etchants, as to prove if their shear bond strength was closely related. As it is a well-known fact that EDTA could be less damaging to the enamel during etching and hence can be an alternative for etching of primary teeth. Materials and Methods: For the study 60 caries-free primary molars were used, they were sectioned in the middle, after making area for bonding; the marked area was then etched using different etchants for 30 s. Each of the teeth was then rinsed and bonded with composite resin and thermocycling was done. Shear bond strength testing was done on the composite using Universal Testing Machine. Results: Results of the study showed that phosphoric acid showed the highest bond strength, closely followed by Single Etch (Adper Prompt) and NRC, then by EDTA. Conclusions: About 24% EDTA can be another comparable replacement for phosphoric acid if used with a Single Etch Primer, like Prime and Bond NT on primary teeth. 34% phosphoric acid has the highest bond strength values with composite resin. Single etch followed by NRC has the second and third highest bond strength values, which are comparable to phosphoric acid. PMID:26464540

  16. Using Multiple Bonding Strategies.

    PubMed

    Larson, Thomas D

    2015-01-01

    There are many ways to bond to tooth structure, some micro-mechanical some chemical, some a combination. Different dentin bonding materials have different bonding strengths to differently prepared surfaces, and because of differences in their nature, different areas of tooth structure present peculiar bonding challenges. This paper will review a variety of material types, elucidating their particular bonding strengths and commenting on improved bonding strategies to increase durability, strength, and favorable pulpal response. In this discussion, resin dentin bonding systems, glass ionomers, Gluma, resin cements, and newer combined products will br reviewed. PMID:26485903

  17. Using Multiple Bonding Strategies.

    PubMed

    Larson, Thomas D

    2015-01-01

    There are many ways to bond to tooth structure, some micro-mechanical some chemical, some a combination. Different dentin bonding materials have different bonding strengths to differently prepared surfaces, and because of differences in their nature, different areas of tooth structure present peculiar bonding challenges. This paper will review a variety of material types, elucidating their particular bonding strengths and commenting on improved bonding strategies to increase durability, strength, and favorable pulpal response. In this discussion, resin dentin bonding systems, glass ionomers, Gluma, resin cements, and newer combined products will br reviewed.

  18. Characteristics and Conceptual Framework of the Easy-Play Model

    ERIC Educational Resources Information Center

    Lu, Chunlei; Steele, Kyle

    2014-01-01

    The Easy-Play Model offers a defined framework to organize games that promote an inclusive and enjoyable sport experience. The model can be implemented by participants playing sports in educational, recreational or social contexts with the goal of achieving an active lifestyle in an inclusive, cooperative and enjoyable environment. The Easy-Play…

  19. Outdoor Education Equipment: Plans for Easy-to-Make Items.

    ERIC Educational Resources Information Center

    Bachert, Russel E., Jr.; Snooks, Emerson L.

    The document is a versatile publication providing an outdoor education aid for teaching elementary (beginning with grade 4), high school, and college students. The process is one of learning by doing; i.e., the students construct their own instruments for field studies. The book presents over 100 ideas in an easy-to-follow, easy-to-use format.…

  20. Influence of chlorhexidine concentration on the durability of etch-and-rinse dentin bonds: a 12-month in vitro study

    PubMed Central

    Breschi, Lorenzo; Cammelli, Federica; Visintini, Erika; Mazzoni, Annalisa; Vita, Francesca; Carrilho, Marcela; Cadenaro, Milena; Foulger, Stephen; Tay, Franklin R; Pashley, David; Di Lenarda, Roberto

    2013-01-01

    Objective To investigate the effect of 0.2% and 2% chlorhexidine (CHX) used as a therapeutic primer on the long-term bond strengths of two etch-and-rinse adhesive systems. Methods Adper Scotchbond 1XT (SB1) and XP-Bond (XPB) were evaluated. Etched dentin substrates were assigned to six treatment groups: (1) 0.2% CHX + SB1; (2) 2% CHX + SB1; (3) SB1 (control); (4) 0.2% CHX + XPB; (5) 2% CHX + XPB; (6) XPB (control). Composite build-ups were made and beams prepared for microtensile bond strength test. Beams were divided in three subgroups and either immediately pulled to failure or stored in artificial saliva for 6 or 12 months prior to testing. Data were evaluated by three-way ANOVA. Additional adhesive interfaces were prepared to investigate nanoleakage expression by TEM. Results SB1 and XPB showed similar immediate bond strength values with or without CHX pre-treatment (p>0.05). After 12 months, bonds fell from 43.9 ± 9.5 MPa to 20.1 ± 5.4 MPa and from 39.6 ± 9.4 MPa to 14.2 ± 5.0 MPa in control specimens for SB1 and XPB respectively, while bond fell only from 41.9±9.6MPa to 33.2 ± 8.3 MPa and 38.3 ± 8.9 MPa to 26.5 ± 10.9 (for SB1 and XPB respectively) when 0.2% CHX was previously used. CHX concentration did not affect bond strength values (0.2% vs 2%, p>.05). Nanoleakage increased during aging in controls, but reduced silver deposits were found in CHX-treated specimens. Conclusions Chlorhexidine significantly reduced the loss of bond strength seen in control bonds. Since no bacterial growth was present in the aging conditions, the results of this study suggest that endogenous factors thought to degrade the adhesive interface can be inhibited by CHX. Further in vivo trials should confirm the role of CHX in bond durability. PMID:19603582

  1. Hydroxide-catalyzed bonding

    NASA Technical Reports Server (NTRS)

    Gwo, Dz-Hung (Inventor)

    2003-01-01

    A method of bonding substrates by hydroxide-catalyzed hydration/dehydration involves applying a bonding material to at least one surface to be bonded, and placing the at least one surface sufficiently close to another surface such that a bonding interface is formed between them. A bonding material of the invention comprises a source of hydroxide ions, and may optionally include a silicate component, a particulate filling material, and a property-modifying component. Bonding methods of the invention reliably and reproducibly provide bonds which are strong and precise, and which may be tailored according to a wide range of possible applications. Possible applications for bonding materials of the invention include: forming composite materials, coating substrates, forming laminate structures, assembly of precision optical components, and preparing objects of defined geometry and composition. Bonding materials and methods of preparing the same are also disclosed.

  2. Chlorhexidine-containing acid conditioner preserves the longevity of resin-dentin bonds.

    PubMed

    Stanislawczuk, R; Amaral, R C; Zander-Grande, C; Gagler, D; Reis, A; Loguercio, A D

    2009-01-01

    The current study evaluated the effect of 2% chlorhexidine digluconate (CHX) on the immediate and six-month resin-dentin bond strength (BS) and nanoleakage pattern (NL) of etch-and-rinse adhesives when applied in aqueous or associated to the phosphoric acid conditioner. The occlusal enamel of 42 caries-free extracted molars was removed in order to expose a flat dentin surface. In groups 1 and 2 (control-C), the surfaces were acid etched with conventional phosphoric acid, and the adhesives Prime&Bond NT (PB) and Adper Single Bond 2 (SB) were applied after rinsing, drying and rewetting with water. In groups 3 and 4 (Ac/CHX), the adhesives were applied in a similar manner, however, a 2% CHX-containing acid was previously applied. In groups 5 and 6 (CHX), the adhesives were applied according to the control group; however, the rewetting procedure was performed with an aqueous solution of 2% CHX for 60 seconds. Composite buildups (Opallis, FGM) were constructed incrementally, and the specimens were longitudinally sectioned in the "x" and "y" directions to obtain bonded sticks (0.8 mm2) to be tested in tension at 0.5 mm/minute immediately or after six months of water storage. For NL, two bonded sticks from each tooth were coated with nail varnish, placed in silver nitrate and polished down with SiC paper. Resin-dentin interfaces were analyzed by EDX-SEM. The BS and NL data from each adhesive was submitted to two-way repeated measures ANOVA and Tukey's test (alpha=0.05). After six months of water storage, significant reductions in BS were observed for both adhesives in the control group (p<0.05). When Ac/CHX or CHX was used, no significant reductions in BS were observed for both systems. Nanoleakage was more evident in the control group than in the experimental groups (p<0.05), even after six months. The use of CHX in an aqueous solution or associated with the acid conditioner was effective for reducing degradation of resin-dentin bonds after six months of water storage

  3. An Easy Classroom Experiment on the Supercooling of Water

    ERIC Educational Resources Information Center

    Gianino, Concetto

    2007-01-01

    The change from the state of supercooling to the solid state of ice is called superfreezing. This process is not uncommon and takes place in domestic freezers. It is also easy to reproduce in the laboratory. (Contains 6 figures.)

  4. MedlinePlus FAQ: Easy-to-Read Documents

    MedlinePlus

    ... faq/easytoread.html Question: How can I locate materials on MedlinePlus that are easy to read and ... public, not for health professionals. But, not all materials on MedlinePlus are at the same reading level. ...

  5. Diffusion bonding aeroengine components

    NASA Astrophysics Data System (ADS)

    Fitzpatrick, G. A.; Broughton, T.

    1988-10-01

    The use of diffusion bonding processes at Rolls-Royce for the manufacture of titanium-alloy aircraft engine components and structures is described. A liquid-phase diffusion bonding process called activated diffusion bonding has been developed for the manufacture of the hollow titanium wide chord fan blade. In addition, solid-state diffusion bonding is being used in the manufacture of hollow vane/blade airfoil constructions mainly in conjunction with superplastic forming and hot forming techniques.

  6. Bond percolation in films

    NASA Astrophysics Data System (ADS)

    Korneta, W.; Pytel, Z.

    1988-04-01

    Bond percolation in films with simple cubic structure is considered. It is assumed that the probability of a bond being present between nearest-neighbor sites depends on the distances to surfaces. Based on the relation between the Potts model and the bond percolation model, and using the mean-field approximation, the phase diagram and profiles of the percolation probability have been obtained.

  7. Rapid adhesive bonding concepts

    NASA Technical Reports Server (NTRS)

    Stein, B. A.; Tyeryar, J. R.; Hodges, W. T.

    1984-01-01

    Adhesive bonding in the aerospace industry typically utilizes autoclaves or presses which have considerable thermal mass. As a consequence, the rates of heatup and cooldown of the bonded parts are limited and the total time and cost of the bonding process is often relatively high. Many of the adhesives themselves do not inherently require long processing times. Bonding could be performed rapidly if the heat was concentrated in the bond lines or at least in the adherends. Rapid adhesive bonding concepts were developed to utilize induction heating techniques to provide heat directly to the bond line and/or adherends without heating the entire structure, supports, and fixtures of a bonding assembly. Bonding times for specimens are cut by a factor of 10 to 100 compared to standard press bonding. The development of rapid adhesive bonding for lap shear specimens (per ASTM D1003 and D3163), for aerospace panel bonding, and for field repair needs of metallic and advanced fiber reinforced polymeric matrix composite structures are reviewed.

  8. Acrylic mechanical bond tests

    SciTech Connect

    Wouters, J.M.; Doe, P.J.

    1991-02-01

    The tensile strength of bonded acrylic is tested as a function of bond joint thickness. 0.125 in. thick bond joints were found to posses the maximum strength while the acceptable range of joints varied from 0.063 in. to almost 0.25 in. Such joints are used in the Sudbury Neutrino Observatory.

  9. TOPICAL REVIEW: Progress in cold roll bonding of metals

    NASA Astrophysics Data System (ADS)

    Li, Long; Nagai, Kotobu; Yin, Fuxing

    2008-04-01

    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.

  10. Bonding thermoplastic polymers

    DOEpatents

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

    2008-06-24

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

  11. Simple Bond Cleavage

    SciTech Connect

    Gary S. Groenewold

    2005-08-01

    Simple bond cleavage is a class of fragmentation reactions in which a single bond is broken, without formation of new bonds between previously unconnected atoms. Because no bond making is involved, simple bond cleavages are endothermic, and activation energies are generally higher than for rearrangement eliminations. The rate of simple bond cleavage reactions is a strong function of the internal energy of the molecular ion, which reflects a loose transition state that resembles reaction products, and has a high density of accessible states. For this reason, simple bond cleavages tend to dominate fragmentation reactions for highly energized molecular ions. Simple bond cleavages have negligible reverse activation energy, and hence they are used as valuable probes of ion thermochemistry, since the energy dependence of the reactions can be related to the bond energy. In organic mass spectrometry, simple bond cleavages of odd electron ions can be either homolytic or heterolytic, depending on whether the fragmentation is driven by the radical site or the charge site. Simple bond cleavages of even electron ions tend to be heterolytic, producing even electron product ions and neutrals.

  12. Origin of a magnetic easy axis in pipeline steel

    NASA Astrophysics Data System (ADS)

    Clapham, L.; Heald, C.; Krause, T.; Atherton, D. L.; Clark, P.

    1999-08-01

    Oil and gas pipelines are generally magnetically anisotropic, with a magnetic easy axis in the pipe axial direction. This is of interest because magnetic flux leakage tools are commonly used for the detection and sizing of defects. In the present study we investigate the origin of this magnetic easy axis, using an angular magnetic Barkhausen noise technique to characterize the magnetic anisotropy. The texture, microstructure, and residual stress are examined as possible causes of the easy axis, using x-ray pole figure analysis and microstructural examination along with high and low temperature annealing treatments. Our results indicate that plastic deformation and residual stress are responsible for the magnetic easy axis, since an elimination of the residual stresses through low temperature "stress relief" heat treatment produces a magnetically isotropic structure without altering the texture or microstructure. X-ray pole figure analysis supports the conclusion that magnetic anisotropy is not related to texture in these materials. We conclude that the axial magnetic easy axis is due to a compressive residual hoop stress resulting from the cold bending and cold expansion of the pipe during processing.

  13. Weak bond screening system

    NASA Astrophysics Data System (ADS)

    Chuang, S. Y.; Chang, F. H.; Bell, J. R.

    Consideration is given to the development of a weak bond screening system which is based on the utilization of a high power ultrasonic (HPU) technique. The instrumentation of the prototype bond strength screening system is described, and the adhesively bonded specimens used in the system developmental effort are detailed. Test results obtained from these specimens are presented in terms of bond strength and level of high power ultrasound irradiation. The following observations were made: (1) for Al/Al specimens, 2.6 sec of HPU irradiation will screen weak bond conditions due to improper preparation of bonding surfaces; (2) for composite/composite specimens, 2.0 sec of HPU irradiation will disrupt weak bonds due to under-cured conditions; (3) for Al honeycomb core with composite skin structure, 3.5 sec of HPU irradiation will disrupt weak bonds due to bad adhesive or oils contamination of bonding surfaces; and (4) for Nomex honeycomb with Al skin structure, 1.3 sec of HPU irradiation will disrupt weak bonds due to bad adhesive.

  14. Bonded semiconductor substrate

    DOEpatents

    Atwater, Jr.; Harry A. , Zahler; James M.

    2010-07-13

    Ge/Si and other nonsilicon film heterostructures are formed by hydrogen-induced exfoliation of the Ge film which is wafer bonded to a cheaper substrate, such as Si. A thin, single-crystal layer of Ge is transferred to Si substrate. The bond at the interface of the Ge/Si heterostructures is covalent to ensure good thermal contact, mechanical strength, and to enable the formation of an ohmic contact between the Si substrate and Ge layers. To accomplish this type of bond, hydrophobic wafer bonding is used, because as the invention demonstrates the hydrogen-surface-terminating species that facilitate van der Waals bonding evolves at temperatures above 600.degree. C. into covalent bonding in hydrophobically bound Ge/Si layer transferred systems.

  15. BONDING ALUMINUM METALS

    DOEpatents

    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.

  16. Chemical bonding technology

    NASA Technical Reports Server (NTRS)

    Plueddemann, E.

    1986-01-01

    Primers employed in bonding together the various material interfaces in a photovoltaic module are being developed. The approach develops interfacial adhesion by generating actual chemical bonds between the various materials bonded together. The current status of the program is described along with the progress toward developing two general purpose primers for ethylene vinyl acetate (EVA), one for glass and metals, and another for plastic films.

  17. Equilibrium CO bond lengths

    NASA Astrophysics Data System (ADS)

    Demaison, Jean; Császár, Attila G.

    2012-09-01

    Based on a sample of 38 molecules, 47 accurate equilibrium CO bond lengths have been collected and analyzed. These ultimate experimental (reEX), semiexperimental (reSE), and Born-Oppenheimer (reBO) equilibrium structures are compared to reBO estimates from two lower-level techniques of electronic structure theory, MP2(FC)/cc-pVQZ and B3LYP/6-311+G(3df,2pd). A linear relationship is found between the best equilibrium bond lengths and their MP2 or B3LYP estimates. These (and similar) linear relationships permit to estimate the CO bond length with an accuracy of 0.002 Å within the full range of 1.10-1.43 Å, corresponding to single, double, and triple CO bonds, for a large number of molecules. The variation of the CO bond length is qualitatively explained using the Atoms in Molecules method. In particular, a nice correlation is found between the CO bond length and the bond critical point density and it appears that the CO bond is at the same time covalent and ionic. Conditions which permit the computation of an accurate ab initio Born-Oppenheimer equilibrium structure are discussed. In particular, the core-core and core-valence correlation is investigated and it is shown to roughly increase with the bond length.

  18. Five Easy Principles to Make Math Moments Count

    ERIC Educational Resources Information Center

    Cutler, Carrie S.

    2011-01-01

    Preschool children are learning so many skills--how to cut with scissors, zip zippers, recognize the alphabet and their names, and share toys with others. A strong academic curriculum also requires that children learn more about math (National Council of Teachers of Mathematics [NCTM], 2000). By following the five easy principles outlined here,…

  19. Myopia Glasses and Optical Power Estimation: An Easy Experiment

    NASA Astrophysics Data System (ADS)

    Ribeiro, Jair Lúcio Prados

    2015-02-01

    Human eye optics is a common high school physics topic and students usually show a great interest during our presentation of this theme. In this article, we present an easy way to estimate a diverging lens' optical power from a simple experiment involving myopia eyeglasses and a smartphone flashlight.

  20. Is Easy Read Information Really Easier to Read?

    ERIC Educational Resources Information Center

    Hurtado, B.; Jones, L.; Burniston, F.

    2014-01-01

    Background: Producing accessible information regarding health issues is very important in order to ensure that people with intellectual disabilities (ID) have equal access to services and can make informed decisions about their treatment. Method: This study examined whether an Easy Read leaflet improved service users' comprehension and…

  1. Myopia Glasses and Optical Power Estimation: An Easy Experiment

    ERIC Educational Resources Information Center

    Ribeiro, Jair Lúcio Prados

    2015-01-01

    Human eye optics is a common high school physics topic and students usually show a great interest during our presentation of this theme. In this article, we present an easy way to estimate a diverging lens' optical power from a simple experiment involving myopia eyeglasses and a smartphone flashlight.

  2. The Rocker (An Easy Anharmonic Oscillator for Classroom Demonstration)

    ERIC Educational Resources Information Center

    Lieberherr, Martin

    2013-01-01

    Every instructor should know some easy examples of anharmonic oscillations. The rocking of an empty wine bottle or a slender beer glass is one of those: The angle is not a sinusoidal function of time and the period is not independent of the amplitude, not even for small amplitudes. But care has to be taken that the glass does not slip or rotate…

  3. Pheromone Caterpillar Trails: An Easy Lab Exercise for the Classroom

    ERIC Educational Resources Information Center

    Travis, Holly

    2003-01-01

    Lab activities using live specimens always seem to catch students' attention faster than those using inanimate materials. For example, many teachers are familiar with the activities using goldfish to study the effect of temperature on respiration rate. Insects are particularly useful because they are cheap, easy to find, and have a certain "yuck"…

  4. EASY AT-Food for Thought: The Minibook

    ERIC Educational Resources Information Center

    Schoonover, Judith

    2015-01-01

    Not all technology requires plugs, batteries, or software updates. Sometimes the simplest tools can make all the difference in the world, and open doors (and minds) to other possibilities. One such tool is a minibook constructed by a single sheet of cleverly folded paper. A minibook is a cost-effective, easy to revise and replace,…

  5. Software Updates: Web Design--Software that Makes It Easy!

    ERIC Educational Resources Information Center

    Pattridge, Gregory C.

    2002-01-01

    This article discusses Web design software that provides an easy-to-use interface. The "Netscape Communicator" is highlighted for beginning Web page construction and step-by-step instructions are provided for starting out, page colors and properties, indents, bulleted lists, tables, adding links, navigating long documents, creating e-mail links,…

  6. A Geostationary Earth Orbit Satellite Model Using Easy Java Simulation

    ERIC Educational Resources Information Center

    Wee, Loo Kang; Goh, Giam Hwee

    2013-01-01

    We develop an Easy Java Simulation (EJS) model for students to visualize geostationary orbits near Earth, modelled using a Java 3D implementation of the EJS 3D library. The simplified physics model is described and simulated using a simple constant angular velocity equation. We discuss four computer model design ideas: (1) a simple and realistic…

  7. An Easy Way to Show Memory Color Effects

    PubMed Central

    2016-01-01

    This study proposes and evaluates a simple stimulus display that allows one to measure memory color effects (the effect of object knowledge and memory on color perception). The proposed approach is fast and easy and does not require running an extensive experiment. It shows that memory color effects are robust to minor variations due to a lack of color calibration. PMID:27698988

  8. An Easy-to-Assemble Three-Part Galvanic Cell

    ERIC Educational Resources Information Center

    Eggen, Per-Odd; Skaugrud, Brit

    2015-01-01

    The galvanic cell presented in this article is made of only three parts, is easy to assemble, and can light a red light emitting diode (LED). The three cell components consist of a piece of paper with copper sulfate, a piece of paper with sodium sulfate, and a piece of magnesium ribbon. Within less than 1 h, students have time to discuss the…

  9. easyCBM Norms. 2014 Edition. Technical Report #1409

    ERIC Educational Resources Information Center

    Saven, Jessica L.; Tindal, Gerald; Irvin, P. Shawn; Farley, Dan; Alonzo, Julie

    2014-01-01

    Previous norms for the easyCBM assessment system were computed using scores from all students who took each measure for every grade and benchmark season (fall, winter, and spring). During the 2013-­14 school year, new national norms were developed to more accurately (proportionately) represent reading and mathematics performance by two variables:…

  10. Fast and Easy Searching of Files in Unisys 2200 Computers

    NASA Technical Reports Server (NTRS)

    Snook, Bryan E.

    2010-01-01

    A program has been written to enable (1) fast and easy searching of symbolic files for one or more strings of characters, dates, or numerical values in specific fields or columns and (2) summarizing results of searching other fields or columns.

  11. Everyday Science: Fun and Easy Projects for Making Practical Things.

    ERIC Educational Resources Information Center

    Levine, Shar; Johnstone, Leslie

    This book contains 25 experiments designed to help students understand some of the science used every day. Each experiment includes a list of materials, a series of easy-to-follow steps, an explanation of the scientific principle demonstrated, and additional scientific facts and information. No special or expensive materials are required.…

  12. An Easy Way to Show Memory Color Effects

    PubMed Central

    2016-01-01

    This study proposes and evaluates a simple stimulus display that allows one to measure memory color effects (the effect of object knowledge and memory on color perception). The proposed approach is fast and easy and does not require running an extensive experiment. It shows that memory color effects are robust to minor variations due to a lack of color calibration.

  13. Gel Electrophoresis--The Easy Way for Students

    ERIC Educational Resources Information Center

    VanRooy, Wilhelmina; Sultana, Khalida

    2010-01-01

    This article describes a simple, inexpensive, easy to conduct gel-electrophoresis activity using food dyes. It is an alternative to the more expensive counterparts which require agarose gel, DNA samples, purchased chamber and Tris-borate-EDTA buffer. We suggest some learning activities for senior biology students along with comments on several…

  14. Easy Bookmaking: Thematic Pop-Ups, Cards, and Shape Books.

    ERIC Educational Resources Information Center

    Walsh, Natalie

    Developed to be easy and require minimum preparation time, yet give high-impact results, this book offers tried-and-true teacher-tested book projects for primary grades K-3. The book's topics connect curriculum areas: creative writing, science, social studies, and math. Projects outlined in the book require few materials and can be done at…

  15. Technical Manual: easyCBM. Technical Report #1408

    ERIC Educational Resources Information Center

    Anderson, Daniel; Alonzo, Julie; Tindal, Gerald; Farley, Dan; Irvin, P. Shawn; Lai, Cheng-Fei; Saven, Jessica L.; Wray, Kraig A.

    2014-01-01

    Since the easyCBM© learning system was first published in 2006, over $8 million of federal funding (both from the Office of Special Education Programs and more recently from the Institute of Education Sciences) has been used to develop, study, and refine the assessments available on the system. This Technical Manual summarizes the ongoing research…

  16. 75 Quick and Easy Solutions to Common Classroom Disruptions

    ERIC Educational Resources Information Center

    Harris, Bryan; Goldberg, Cassandra

    2012-01-01

    This very well organized book is packed with practical solutions to the most common classroom problems--side talk, rude behavior, calling out, students losing focus, and students refusing even to try. Every solution is classroom-tested, highly effective, and quick and easy to implement! Use this book to help make your classroom a happier, more…

  17. Water interaction and bond strength to dentin of dye-labelled adhesive as a function of the addition of rhodamine B

    PubMed Central

    WANG, Linda; BIM, Odair; LOPES, Adolfo Coelho de Oliveira; FRANCISCONI-DOS-RIOS, Luciana Fávaro; MAENOSONO, Rafael Massunari; D’ALPINO, Paulo Henrique Perlatti; HONÓRIO, Heitor Marques; ATTA, Maria Teresa

    2016-01-01

    ABSTRACT Objective This study investigated the effect of the fluorescent dye rhodamine B (RB) for interfacial micromorphology analysis of dental composite restorations on water sorption/solubility (WS/WSL) and microtensile bond strength to dentin (µTBS) of a 3-step total etch and a 2-step self-etch adhesive system. Material and Methods The adhesives Adper Scotchbond Multi-Purpose (MP) and Clearfil SE Bond (SE) were mixed with 0.1 mg/mL of RB. For the WS/WSL tests, cured resin disks (5.0 mm in diameter x 0.8 mm thick) were prepared and assigned into four groups (n=10): MP, MP-RB, SE, and SE-RB. For µTBS assessment, extracted human third molars (n=40) had the flat occlusal dentin prepared and assigned into the same experimental groups (n=10). After the bonding and restoration procedures, specimens were sectioned in rectangular beams, stored in water and tested after seven days or after 12 months. The failure mode of fractured specimens was qualitatively evaluated under optical microscope (x40). Data from WS/WSL and µTBS were assessed by one-way and three-way ANOVA, respectively, and Tukey’s test (α=5%). Results RB increased the WSL of MP and SE. On the other hand, WS of both MP and SE was not affected by the addition of RB. No significance in µTBS between MP and MP-RB for seven days or one year was observed, whereas for SE a decrease in the µTBS means occurred in both storage times. Conclusions RB should be incorporated into non-simplified DBSs with caution, as it can interfere with their physical-mechanical properties, leading to a possible misinterpretation of bonded interface. PMID:27556201

  18. Evaluation of microshear bond strength of resin composites to enamel of dental adhesive systems associated with Er,Cr:YSGG laser

    NASA Astrophysics Data System (ADS)

    Cassimiro-Silva, Patricia F.; Zezell, Denise M.; Monteiro, Gabriela Q. d. M.; Benetti, Carolina; de Paula Eduardo, Carlos; Gomes, Anderson S. L.

    2016-02-01

    The aim of this in vitro study was to evaluate the microshear bond strength (μSBS) of resin composite to enamel etching by Er,Cr:YSGG laser with the use of two differents adhesives systems. Fifty freshly extracted human molars halves were embedded in acrylic resin before preparation for the study, making a total of up to 100 available samples. The specimens were randomly assigned into six groups (η=10) according to substrate pre-treatment and adhesive system on the enamel. A two-step self-etching primer system (Clearfil SE Bond) and a universal adhesive used as an etch-andrinse adhesive (Adper Single Bond Universal) were applied to the nonirradiated enamel surface according to manufacturer's instructions, as control groups (Control CF and Control SB, respectively). For the other groups, enamel surfaces were previously irradiated with the Er,Cr:YSGG laser with 0.5 W, 75 mJ and 66 J/cm2 (CF 5 Hz and SB 5 Hz) and 1.25 W, 50 mJ and 44 J/cm2 (CF 15 Hz and SB 15 Hz). Irradiation was performed under air (50%) and water (50%) cooling. An independent t-test was performed to compare the adhesive systems. Mean μSBS ± sd (MPa) for each group was 16.857 +/- 2.61, 17.87 +/- 5.83, 12.23 +/- 2.02, 9.88 +/- 2.26, 15.94 +/- 1.98, 17.62 +/- 2.10, respectively. The control groups and the 50 mJ laser groups showed no statistically significant differences, regardless of the adhesive system used. The results obtained lead us to affirm that the bonding interaction of adhesives to enamel depends not only on the morphological aspects of the dental surface, but also on the characteristics of the adhesive employed and the parameters of the laser.

  19. The Sibling Bond.

    ERIC Educational Resources Information Center

    Bank, Stephen P.; Kahn, Michael D.

    The relationships among brothers and sisters are infinitely varied, but whatever their characteristics, these bonds last throughout life. This book examines the sibling relationship as a distinctive emotional, passionate, painful, and solacing power. Chapter 1, "Unraveling the Sibling Bond," addresses research on siblings and development of the…

  20. Chemical Bonds I

    ERIC Educational Resources Information Center

    Sanderson, R. T.

    1972-01-01

    Chemical bonding is discussed from a bond energy, rather than a wave mechanics, viewpoint. This approach is considered to be more suitable for the average student. (The second part of the article will appear in a later issue of the journal.) (AL)

  1. Universal nanopatternable interfacial bonding.

    PubMed

    Ding, Yuzhe; Garland, Shaun; Howland, Michael; Revzin, Alexander; Pan, Tingrui

    2011-12-01

    A nanopatternable polydimethylsiloxane (PDMS) oligomer layer is demonstrated as an interfacial adhesive for its intrinsic transferability and universal adhesiveness. Utilizing the well-established surface modification and bonding techniques of PDMS surfaces, irreversible bonding is formed (up to 400 kPa) between a wide range of substrate pairs, representing ones within and across different materials categories, including metals, ceramics, thermoset, and thermoplastic polymers.

  2. The dissociative bond.

    PubMed

    Gordon, Nirit

    2013-01-01

    Dissociation leaves a psychic void and a lingering sense of psychic absence. How do 2 people bond while they are both suffering from dissociation? The author explores the notion of a dissociative bond that occurs in the aftermath of trauma--a bond that holds at its core an understanding and shared detachment from the self. Such a bond is confined to unspoken terms that are established in the relational unconscious. The author proposes understanding the dissociative bond as a transitional space that may not lead to full integration of dissociated knowledge yet offers some healing. This is exemplified by R. Prince's (2009) clinical case study. A relational perspective is adopted, focusing on the intersubjective aspects of a dyadic relationship. In the dissociative bond, recognition of the need to experience mutual dissociation can accommodate a psychic state that yearns for relationship when the psyche cannot fully confront past wounds. Such a bond speaks to the need to reestablish a sense of human relatedness and connection when both parties in the relationship suffer from disconnection. This bond is bound to a silence that becomes both a means of protection against the horror of traumatic memory and a way to convey unspoken gestures toward the other.

  3. Mother-Child Bonding.

    ERIC Educational Resources Information Center

    Pearce, Joseph Chilton

    1994-01-01

    Examines the nature of mother-child bonding from the prenatal stage through early infancy, discussing how the mother's actions, even before birth, stimulate her child's senses. Explains the crucial role that physical contact, breastfeeding, and visual stimuli have on mother-child bonding in human and animal newborns. (MDM)

  4. The dissociative bond.

    PubMed

    Gordon, Nirit

    2013-01-01

    Dissociation leaves a psychic void and a lingering sense of psychic absence. How do 2 people bond while they are both suffering from dissociation? The author explores the notion of a dissociative bond that occurs in the aftermath of trauma--a bond that holds at its core an understanding and shared detachment from the self. Such a bond is confined to unspoken terms that are established in the relational unconscious. The author proposes understanding the dissociative bond as a transitional space that may not lead to full integration of dissociated knowledge yet offers some healing. This is exemplified by R. Prince's (2009) clinical case study. A relational perspective is adopted, focusing on the intersubjective aspects of a dyadic relationship. In the dissociative bond, recognition of the need to experience mutual dissociation can accommodate a psychic state that yearns for relationship when the psyche cannot fully confront past wounds. Such a bond speaks to the need to reestablish a sense of human relatedness and connection when both parties in the relationship suffer from disconnection. This bond is bound to a silence that becomes both a means of protection against the horror of traumatic memory and a way to convey unspoken gestures toward the other. PMID:23282044

  5. Shape Bonding method

    NASA Technical Reports Server (NTRS)

    Pontius, James T. (Inventor)

    2010-01-01

    The present invention is directed to a method of bonding at least two surfaces together. The methods step of the present invention include applying a strip of adhesive to a first surface along a predefined outer boundary of a bond area and thereby defining a remaining open area there within. A second surface, or gusset plate, is affixed onto the adhesive before the adhesive cures. The strip of adhesive is allowed to cure and then a second amount of adhesive is applied to cover the remaining open area and substantially fill a void between said first and second surfaces about said bond area. A stencil may be used to precisely apply the strip of adhesive. When the strip cures, it acts as a dam to prevent overflow of the subsequent application of adhesive to undesired areas. The method results in a precise bond area free of undesired shapes and of a preferred profile which eliminate the drawbacks of the prior art bonds.

  6. Wood Bond Testing

    NASA Technical Reports Server (NTRS)

    1989-01-01

    A joint development program between Hartford Steam Boiler Inspection Technologies and The Weyerhaeuser Company resulted in an internal bond analyzer (IBA), a device which combines ultrasonics with acoustic emission testing techniques. It is actually a spinoff from a spinoff, stemming from a NASA Lewis invented acousto-ultrasonic technique that became a system for testing bond strength of composite materials. Hartford's parent company, Acoustic Emission Technology Corporation (AET) refined and commercialized the technology. The IBA builds on the original system and incorporates on-line process control systems. The IBA determines bond strength by measuring changes in pulsar ultrasonic waves injected into a board. Analysis of the wave determines the average internal bond strength for the panel. Results are displayed immediately. Using the system, a mill operator can adjust resin/wood proportion, reduce setup time and waste, produce internal bonds of a consistent quality and automatically mark deficient products.

  7. EasyBowling: a virtual bowling system for small space

    NASA Astrophysics Data System (ADS)

    Pan, Zhigeng; Huang, Jin; Xu, Weiwei; Zhou, Kun; Shi, Jiaoying

    2003-04-01

    In this paper we describe a virtual bowling game machine called EasyBowling Machine, which is designed and implemented based on techniques such as Virtual Reality, animation, and image processing. To introduce Virtual Reality technique into this virtual bowling game, our system provides a real game mode: players play the game by throwing a real bowling ball, and then the EasyBowling system uses a PC Camera to detect the motion of the real bowling ball. After the motion parameters (ball direction, ball force, et al.) are computed, the movement of the bowling ball and its collision with pins are simulated on a large display screen. The most obvious advantage of such bowling game machine over other existing bowling games is that the system integrates body exercise into game playing. The implementation techniques are discussed in detail, and the prototype system illustrates the feasibility and efficiency of our method.

  8. The aftereffect in ultrathin ferromagnetic films with easy perpendicular direction

    NASA Astrophysics Data System (ADS)

    Schmidt, W.

    1992-08-01

    We consider a model of the aftereffect where the walls are detached from pin defects by vibrations. Dependence is obtained between the activation energy on the external field which is used to estimate the distance between defects, the radius of pin cavity and the stability time in a real film. The calculation is restricted to limp domain walls and ultrathin films with easy perpendicular direction. The model is tested to compare experimental data of the coercive force with a calculated value.

  9. Thoracoscopic esophageal atresia repair made easy. An applicable trick.

    PubMed

    Hiradfar, Mehran; Shojaeian, Reza; Gharavi Fard, Mohammad; Joodi, Marjan; Sabzevari, Alireza; Nazarzade, Reza

    2013-03-01

    Thoracoscopic repair of esophageal atresia is becoming more popular but technical difficulties in handsewn anastomosis still remain challenging. This article presents an easy and applicable maneuver by passing the trans-esophageal tube before starting to suture in order to minimize the gap, reduce the tension over primary sutures and provide a better visualization of posterolateral parts of the anastomosis in thoracoscopic esophageal atresia repair. Using this maneuver makes tying easier and minimizes grasping and crushing damages to the anastomotic site.

  10. High capacity, easy release adhesives from renewable materials.

    PubMed

    Bartlett, Michael D; Crosby, Alfred J

    2014-06-01

    Reversible adhesives composed of renewable materials are presented which achieve high force capacities (810 N) while maintaining easy release (∼ 0.25 N) and reusability. These simple, non-tacky adhesives consist of natural rubber impregnated into stiff natural fiber fabrics, including cotton, hemp, and jute. This versatile approach enables a clear method for designs of environmentally-responsible, reversible adhesives for a wide variety of applications. PMID:24504650

  11. "easyMine" - realistic and systematic mine detection simulation tooltion

    NASA Astrophysics Data System (ADS)

    Böttger, U.; Beier, K.; Biering, B.; Müller, C.; Peichl, M.; Spyra, W.

    2004-05-01

    Mine detection is to date mainly performed with metal detectors, although new methods for UXO detection are explored worldwide. The main problem for the mine detection to date is, that there exist some ideas of which sensor combinations could yield a high score, but until now there is no systematic analysis of mine detection methods together with realistic environmental conditions to conclude on a physically and technically optimized sensor combination. This gap will be removed by a project "easyMine" (Realistic and systematic Mine Detection Simulation Tool) which will result in a simulation tool for optimizing land mine detection in a realistic mine field. The project idea for this software tool is presented, that will simulate the closed chain of mine detection, including the mine in its natural environment, the sensor, the evaluation and application of the measurements by an user. The tool will be modularly designed. Each chain link will be an independent, exchangeable sub- module and will describe a stand alone part of the whole mine detection procedure. The advantage of the tool will be the evaluation of very different kinds of sensor combinations in relation of their real potential for mine detection. Three detection methods (metal detector, GPR and imaging IR-radiometry) will be explained to be introduced into the easyMine software tool in a first step. An actual example for land mine detection problem will be presented and approaches for solutions with easyMine will be shown.

  12. The Halogen Bond.

    PubMed

    Cavallo, Gabriella; Metrangolo, Pierangelo; Milani, Roberto; Pilati, Tullio; Priimagi, Arri; Resnati, Giuseppe; Terraneo, Giancarlo

    2016-02-24

    The halogen bond occurs when there is evidence of a net attractive interaction between an electrophilic region associated with a halogen atom in a molecular entity and a nucleophilic region in another, or the same, molecular entity. In this fairly extensive review, after a brief history of the interaction, we will provide the reader with a snapshot of where the research on the halogen bond is now, and, perhaps, where it is going. The specific advantages brought up by a design based on the use of the halogen bond will be demonstrated in quite different fields spanning from material sciences to biomolecular recognition and drug design. PMID:26812185

  13. The Halogen Bond

    PubMed Central

    2016-01-01

    The halogen bond occurs when there is evidence of a net attractive interaction between an electrophilic region associated with a halogen atom in a molecular entity and a nucleophilic region in another, or the same, molecular entity. In this fairly extensive review, after a brief history of the interaction, we will provide the reader with a snapshot of where the research on the halogen bond is now, and, perhaps, where it is going. The specific advantages brought up by a design based on the use of the halogen bond will be demonstrated in quite different fields spanning from material sciences to biomolecular recognition and drug design. PMID:26812185

  14. Junk-Bond Colleges.

    ERIC Educational Resources Information Center

    Van Der Werf, Martin

    2003-01-01

    Describes how a long-predicted decline in the fortunes of small private colleges is beginning to show up in the bond market, as the number of colleges now rated in the junk category has nearly doubled. (EV)

  15. Bonding with your newborn

    MedlinePlus

    ... and your baby begin to feel a strong attachment with each other. You may feel great love ... L, Saison J, et al. Building a secure attachment bond with your baby. Helpguide.org. www.helpguide. ...

  16. Detecting Defective Solder Bonds

    NASA Technical Reports Server (NTRS)

    Paulson, R.; Barney, J.; Decker, H. J.

    1984-01-01

    Method is noncontact and nondestructive. Technique detects solder bonds in solar array of other large circuit board, using thermal-imaging camera. Board placed between heat lamp and camera. Poor joints indiated by "cold" spots on the infrared image.

  17. Bonding aerogels with polyurethanes

    SciTech Connect

    Matthews, F.M.; Hoffman, D.M.

    1989-11-01

    Aerogels, porous silica glasses with ultra-fine cell size (30nm), are made by a solution gelation (sol-gel) process. The resulting gel is critical point dried to densities from 0.15--0.60 g/cc. This material is machinable, homogeneous, transparent, coatable and bondable. To bond aerogel an adhesive should have long cure time, no attack on the aerogel structure, and high strength. Several epoxies and urethanes were examined to determine if they satisfied these conditions. Bond strengths above 13 psi were found with double bubble and DP-110 epoxies and XI-208/ODA-1000 and Castall U-2630 urethanes. Hardman Kalex Tough Stuff'' A-85 hardness urethane gave 18 psi bond strength. Hardman A-85, Tuff-Stuff'' was selected for further evaluation because it produced bond strengths comparable to the adherend cohesive strength. 5 refs., 2 figs.

  18. Easy creation of polymeric systems for molecular dynamics with Assemble!

    NASA Astrophysics Data System (ADS)

    Degiacomi, Matteo T.; Erastova, Valentina; Wilson, Mark R.

    2016-05-01

    We present Assemble!, a program greatly simplifying the preparation of molecular dynamics simulations of polymeric systems. The program is controlled either via command line or an intuitive Graphical User Interface, and runs on all major operating systems. Assemble! allows the creation of a desired system of polymer chains from constituent monomers, packs the chains into a box according to the required concentration and returns all the files needed for simulation with Gromacs. We illustrate the capabilities of Assemble! by demonstrating the easy preparation of a 300 monomers-long polyisoprene in hexane, and a heterogeneous mixture of polybutadiene.

  19. MYRaf: An Easy Aperture Photometry GUI for IRAF

    NASA Astrophysics Data System (ADS)

    Niaei, M. S.; KiliÇ, Y.; Özeren, F. F.

    2015-07-01

    We describe the design and development of MYRaf, a GUI (Graphical User Interface) that aims to be completely open-source under General Public License (GPL). MYRaf is an easy to use, reliable, and a fast IRAF aperture photometry GUI tool for those who are conversant with text-based software and command-line procedures in GNU/Linux OSs. MYRaf uses IRAF, PyRAF, matplotlib, ginga, alipy, and SExtractor with the general-purpose and high-level programming language Python, and uses the Qt framework.

  20. Strength of Chemical Bonds

    NASA Technical Reports Server (NTRS)

    Christian, Jerry D.

    1973-01-01

    Students are not generally made aware of the extraordinary magnitude of the strengths of chemical bonds in terms of the forces required to pull them apart. Molecular bonds are usually considered in terms of the energies required to break them, and we are not astonished at the values encountered. For example, the Cl2 bond energy, 57.00 kcal/mole, amounts to only 9.46 x 10(sup -20) cal/molecule, a very small amount of energy, indeed, and impossible to measure directly. However, the forces involved in realizing the energy when breaking the bond operate over a very small distance, only 2.94 A, and, thus, f(sub ave) approx. equals De/(r - r(sub e)) must be very large. The forces involved in dissociating the molecule are discussed in the following. In consideration of average forces, the molecule shall be assumed arbitrarily to be dissociated when the atoms are far enough separated so that the potential, relative to that of the infinitely separated atoms, is reduced by 99.5% from the potential of the molecule at the equilibrium bond length (r(sub e)) for Cl2 of 1.988 A this occurs at 4.928 A.

  1. BrailleEasy: One-handed Braille Keyboard for Smartphones.

    PubMed

    Šepić, Barbara; Ghanem, Abdurrahman; Vogel, Stephan

    2015-01-01

    The evolution of mobile technology is moving at a very fast pace. Smartphones are currently considered a primary communication platform where people exchange voice calls, text messages and emails. The human-smartphone interaction, however, is generally optimized for sighted people through the use of visual cues on the touchscreen, e.g., typing text by tapping on a visual keyboard. Unfortunately, this interaction scheme renders smartphone technology largely inaccessible to visually impaired people as it results in slow typing and higher error rates. Apple and some third party applications provide solutions specific to blind people which enables them to use Braille on smartphones. These applications usually require both hands for typing. However, Brailling with both hands while holding the phone is not very comfortable. Furthermore, two-handed Brailling is not possible on smartwatches, which will be used more pervasively in the future. Therefore, we develop a platform for one-handed Brailing consisting of a custom keyboard called BrailleEasy to input Arabic or English Braille codes within any application, and a BrailleTutor application for practicing. Our platform currently supports Braille grade 1, and will be extended to support contractions, spelling correction, and more languages. Preliminary analysis of user studies for blind participants showed that after less than two hours of practice, participants were able to type significantly faster with the BrailleEasy keyboard than with the standard QWERTY keyboard.

  2. [The PIPET or Patient Individual Plate Easy Test].

    PubMed

    Masy, N

    2002-11-01

    The fresh outbreak of allergies and especially that increasingly early for food or even for new pneumallergens (sensitization already in utero) pushes us to test increasingly various and many allergens in children. The insufficiency of compliance of certain children to allergic skin tests encouraged us to seek new diagnostic methods. In our office we developed a new method of diagnosis by multipuncture, individualized and easily adaptable to each child. It is about a fast and reproductible prick-test which avoids stains and smudges due to the application of drops directly on the skin. It makes it possible to initially place easily all the tests on a plate (PIPET or Patient Individual Plate Easy Test) then on the skin by a multipuncture method. The tests can even already be prepared in the days which precede, provided that the plates are put in the fridge, with the name of the patient and the allergens used, for memory. It is about a rigorous test, reliable and careful, easy to carry out even in the most difficult children. PMID:12512189

  3. [Statistical analysis using freely-available "EZR (Easy R)" software].

    PubMed

    Kanda, Yoshinobu

    2015-10-01

    Clinicians must often perform statistical analyses for purposes such evaluating preexisting evidence and designing or executing clinical studies. R is a free software environment for statistical computing. R supports many statistical analysis functions, but does not incorporate a statistical graphical user interface (GUI). The R commander provides an easy-to-use basic-statistics GUI for R. However, the statistical function of the R commander is limited, especially in the field of biostatistics. Therefore, the author added several important statistical functions to the R commander and named it "EZR (Easy R)", which is now being distributed on the following website: http://www.jichi.ac.jp/saitama-sct/. EZR allows the application of statistical functions that are frequently used in clinical studies, such as survival analyses, including competing risk analyses and the use of time-dependent covariates and so on, by point-and-click access. In addition, by saving the script automatically created by EZR, users can learn R script writing, maintain the traceability of the analysis, and assure that the statistical process is overseen by a supervisor.

  4. That Sounds Easy Enough: An Exploration of Data Management Challenges

    NASA Astrophysics Data System (ADS)

    Rosati, A.; Advanced Cooperative Arctic Data; Information Service (Acadis)

    2013-05-01

    Creating an infrastructure that is not ad hoc or ephemeral when much of technology today is itself ad hoc and ephemeral is not an easy task. This paper examines the collaboration process between various stakeholders within the Advanced Cooperative Arctic Data and Information Service (ACADIS) in order to provide insight into data management, data preservation, and data discovery. Specifically, this paper addresses the partnership of Arctic Research Mapping Application Program (ARMAP) and ACADIS. This partnership shows that what may seem like an easy or straight forward request can, in fact, prove challenging. These challenges can only be met through collaboration and good communication. The ACADIS project fosters scientific synthesis and discovery by providing services that make data freely available for access and analysis across multiple disciplines. The goals of ACADIS are to bring together experts to create tools at the forefront of how science will be done. Essentially, we improve the usability and interdisciplinary reuse of arctic data. ACADIS is a joint effort by the National Snow and Ice Data Center (NSIDC), the University Corporation for Atmospheric Research (UCAR), Unidata, and the National Center for Atmospheric Research (NCAR) to provide data archival services, preservation, and access for all projects funded by the National Science Foundation's (NSF) Arctic Science Program (ARC).

  5. Dipole-exchange spin waves in nanotubes composed of uniaxial ferromagnets with "easy-plane" and "easy-axis" anisotropies

    NASA Astrophysics Data System (ADS)

    Gorobets, Yu. I.; Kulish, V. V.

    2015-07-01

    Dipole-exchange spin waves in nanotubes composed of uniaxial ferromagnets are studied. An equation for the magnetic potential of linear spin waves in uniaxial "easy plane" ferromagnets is obtained in the magnetostatic approximation taking into account magnetic dipole-dipole interactions, exchange interactions, and anisotropy effects. A solution is found for this equation and a dispersion relation for these types of spin waves is obtained. The dependence of the spin wave frequency on the total wave number is found for the case of a thin nanotube. An expression is derived for the transverse wave number spectrum.

  6. Biomolecular halogen bonds.

    PubMed

    Ho, P Shing

    2015-01-01

    Halogens are atypical elements in biology, but are common as substituents in ligands, including thyroid hormones and inhibitors, which bind specifically to proteins and nucleic acids. The short-range, stabilizing interactions of halogens - now seen as relatively common in biology - conform generally to halogen bonds characterized in small molecule systems and as described by the σ-hole model. The unique properties of biomolecular halogen bonds (BXBs), particularly in their geometric and energetic relationship to classic hydrogen bonds, make them potentially powerful tools for inhibitor design and molecular engineering. This chapter reviews the current research on BXBs, focusing on experimental studies on their structure-energy relationships, how these studies inform the development of computational methods to model BXBs, and considers how BXBs can be applied to the rational design of more effective inhibitors against therapeutic targets and of new biological-based materials.

  7. Insulation bonding test system

    NASA Technical Reports Server (NTRS)

    Beggs, J. M.; Johnston, G. D.; Coleman, A. D.; Portwood, J. N.; Saunders, J. M.; Redmon, J. W.; Porter, A. C. (Inventor)

    1984-01-01

    A method and a system for testing the bonding of foam insulation attached to metal is described. The system involves the use of an impacter which has a calibrated load cell mounted on a plunger and a hammer head mounted on the end of the plunger. When the impacter strikes the insulation at a point to be tested, the load cell measures the force of the impact and the precise time interval during which the hammer head is in contact with the insulation. This information is transmitted as an electrical signal to a load cell amplifier where the signal is conditioned and then transmitted to a fast Fourier transform (FFT) analyzer. The FFT analyzer produces energy spectral density curves which are displayed on a video screen. The termination frequency of the energy spectral density curve may be compared with a predetermined empirical scale to determine whether a igh quality bond, good bond, or debond is present at the point of impact.

  8. Evaluation of Shear Bond Strength of Total- and Self-etching Adhesive Systems after Application of Chlorhexidine to Dentin Contaminated with a Hemostatic Agent

    PubMed Central

    Sharafeddin, Farahnaz; Farhadpour, Hajar

    2015-01-01

    Statement of the Problem Hemostatic agents may influence the bond strength of different bonding agents. Also, chlorhexidine has shown positive effects on bond strength values and their combination effect has not been reported yet. Purpose The aim of this study was to evaluate the effect of contamination with a hemostatic agent on shear bond strength (SBS) of total- and self-etching adhesive systems and the effect of chlorhexidine application after removal of the hemostatic agent. Materials and Method In this experimental study, the occlusal enamel of each sixty caries-free mandibular molars was removed and their midcoronal dentin was exposed. The specimens were then mounted in auto-polymerizing resin 1mm apical to CEJ. Then, the specimens were divided into 6 groups (n=10) based on contamination with a hemostatic agent (H), application of chlorhexidine (CHX) and the adhesive system used; and then were classified as Group 1: Adper Single Bond (ASB); Group 2: H+ASB; Group 3: H+0.2% CHX+ASB; Group 4: Clearfil SE Bond (CSB); Group 5: H+CSB; Group 6: H+0.2% CHX+CSB. Then, composite resin rods (4×2 mm) were built up on the dentin surfaces and after thermocycling, the SBS (MPa) was evaluated. Statistical analysis was performed using two-way ANOVA and post hoc Tukey tests (p< 0.05). Results There were statistically significant differences between bond strength values of group 1 (ASB) and group 2 (H+ASB) (p< 0.001) and group 1 (ASB) and group 3 (H+CHX+ASB) (p< 0.001). Similarly, significant differences were seen between group 4 (CSB) and group 5 (H+CSB) (p< 0.001) and between group 4 (CSB) and group 6 (H+CHX+CSB) (p< 0.001). Conclusion Contamination with hemostatic agent reduced the SBS of both total- and self-etching adhesive systems. In addition, application of chlorhexidine after the removal of hemostatic agent had a negative effect on SBS of total- and self-etching adhesive systems. PMID:26331146

  9. Cooperativity in beryllium bonds.

    PubMed

    Alkorta, Ibon; Elguero, José; Yáñez, Manuel; Mó, Otilia

    2014-03-01

    A theoretical study of the beryllium bonded clusters of the (iminomethyl)beryllium hydride and (iminomethyl)beryllium fluoride [HC(BeX)=NH, X = H, F] molecules has been carried out at the B3LYP/6-311++G(3df,2p) level of theory. Linear and cyclic clusters have been characterized up to the decamer. The geometric, energetic, electronic and NMR properties of the clusters clearly indicate positive cooperativity. The evolution of the molecular properties, as the size of the cluster increases, is similar to those reported in polymers held together by hydrogen bonds.

  10. Hydrogen bond and halogen bond inside the carbon nanotube

    NASA Astrophysics Data System (ADS)

    Wang, Weizhou; Wang, Donglai; Zhang, Yu; Ji, Baoming; Tian, Anmin

    2011-02-01

    The hydrogen bond and halogen bond inside the open-ended single-walled carbon nanotubes have been investigated theoretically employing the newly developed density functional M06 with the suitable basis set and the natural bond orbital analysis. Comparing with the hydrogen or halogen bond in the gas phase, we find that the strength of the hydrogen or halogen bond inside the carbon nanotube will become weaker if there is a larger intramolecular electron-density transfer from the electron-rich region of the hydrogen or halogen atom donor to the antibonding orbital of the X-H or X-Hal bond involved in the formation of the hydrogen or halogen bond and will become stronger if there is a larger intermolecular electron-density transfer from the electron-rich region of the hydrogen or halogen atom acceptor to the antibonding orbital of the X-H or X-Hal bond. According to the analysis of the molecular electrostatic potential of the carbon nanotube, the driving force for the electron-density transfer is found to be the negative electric field formed in the carbon nanotube inner phase. Our results also show that the X-H bond involved in the formation of the hydrogen bond and the X-Hal bond involved in the formation of the halogen bond are all elongated when encapsulating the hydrogen bond and halogen bond within the carbon nanotube, so the carbon nanotube confinement may change the blue-shifting hydrogen bond and the blue-shifting halogen bond into the red-shifting hydrogen bond and the red-shifting halogen bond. The possibility to replace the all electron nanotube-confined calculation by the simple polarizable continuum model is also evaluated.

  11. Growing perovskite into polymers for easy-processable optoelectronic devices.

    PubMed

    Masi, Sofia; Colella, Silvia; Listorti, Andrea; Roiati, Vittoria; Liscio, Andrea; Palermo, Vincenzo; Rizzo, Aurora; Gigli, Giuseppe

    2015-01-12

    Here we conceive an innovative nanocomposite to endow hybrid perovskites with the easy processability of polymers, providing a tool to control film quality and material crystallinity. We verify that the employed semiconducting polymer, poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV), controls the self-assembly of CH₃NH₃PbI₃ (MAPbI₃) crystalline domains and favors the deposition of a very smooth and homogenous layer in one straightforward step. This idea offers a new paradigm for the implementation of polymer/perovskite nanocomposites towards versatile optoelectronic devices combined with the feasibility of mass production. As a proof-of-concept we propose the application of such nanocomposite in polymer solar cell architecture, demonstrating a power conversion efficiency up to 3%, to date the highest reported for MEH-PPV. On-purpose designed polymers are expected to suit the nanocomposite properties for the integration in diverse optoelectronic devices via facile processing condition.

  12. Growing perovskite into polymers for easy-processable optoelectronic devices.

    PubMed

    Masi, Sofia; Colella, Silvia; Listorti, Andrea; Roiati, Vittoria; Liscio, Andrea; Palermo, Vincenzo; Rizzo, Aurora; Gigli, Giuseppe

    2015-01-01

    Here we conceive an innovative nanocomposite to endow hybrid perovskites with the easy processability of polymers, providing a tool to control film quality and material crystallinity. We verify that the employed semiconducting polymer, poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV), controls the self-assembly of CH₃NH₃PbI₃ (MAPbI₃) crystalline domains and favors the deposition of a very smooth and homogenous layer in one straightforward step. This idea offers a new paradigm for the implementation of polymer/perovskite nanocomposites towards versatile optoelectronic devices combined with the feasibility of mass production. As a proof-of-concept we propose the application of such nanocomposite in polymer solar cell architecture, demonstrating a power conversion efficiency up to 3%, to date the highest reported for MEH-PPV. On-purpose designed polymers are expected to suit the nanocomposite properties for the integration in diverse optoelectronic devices via facile processing condition. PMID:25579988

  13. An easy to compare tool for more readable (physics) textbooks

    NASA Astrophysics Data System (ADS)

    Skorecova, I.; Teleki, A.; Lacsny, B.; Zelenicky, L.

    2016-11-01

    In this article, we show the easy way to compare the readability of two physics school texts written in the same language. We show that the readability of scholar texts depends on the frequency of terms. We compare the readability of texts from two physics textbooks written in Slovak. In these comparisons, we used the frequency of words and terms with a given length (probability distribution) instead of using a readability formula. The concept of analysing the frequency of words in a text agrees with our observations made by eye tracking systems. We verified our results by cloze tests. The method comparing the probability distribution of words and terms of two texts (written in the same language) is very simple, intuitive as well as language independent (in contrary to readability formulae).

  14. A geostationary Earth orbit satellite model using Easy Java Simulation

    NASA Astrophysics Data System (ADS)

    Wee, Loo Kang; Hwee Goh, Giam

    2013-01-01

    We develop an Easy Java Simulation (EJS) model for students to visualize geostationary orbits near Earth, modelled using a Java 3D implementation of the EJS 3D library. The simplified physics model is described and simulated using a simple constant angular velocity equation. We discuss four computer model design ideas: (1) a simple and realistic 3D view and associated learning in the real world; (2) comparative visualization of permanent geostationary satellites; (3) examples of non-geostationary orbits of different rotation senses, periods and planes; and (4) an incorrect physics model for conceptual discourse. General feedback from the students has been relatively positive, and we hope teachers will find the computer model useful in their own classes.

  15. Why School is not Easy: An Analytical Perspective

    NASA Astrophysics Data System (ADS)

    Brooks, David W.

    2011-04-01

    An overarching theory that enables a systematic study of learning recently has been developed. Motivation, for example, is something we all think we know when we see. It was an important step to recognize that motivation can be conceptualized in terms of allocating working memory and especially attention to a learning task. The unified learning model (ULM) was synthesized from the literature with this in mind. Using the ULM as a basis for analysis, it is possible to consider all aspects of learning. A good place to begin concerns schools in general and why, in particular, school is not thought of as being easy. The ULM explains that allocating working memory often requires effort, and any exertion of such effort may be perceived as being hard. This paper is an analysis of school learning and especially science learning (STEM learning) in terms of the ULM.

  16. Easy and hard testbeds for real-time search algorithms

    SciTech Connect

    Koenig, S.; Simmons, R.G.

    1996-12-31

    Although researchers have studied which factors influence the behavior of traditional search algorithms, currently not much is known about how domain properties influence the performance of real-time search algorithms. In this paper we demonstrate, both theoretically and experimentally, that Eulerian state spaces (a super set of undirected state spaces) are very easy for some existing real-time search algorithms to solve: even real-time search algorithms that can be intractable, in general, are efficient for Eulerian state spaces. Because traditional real-time search testbeds (such as the eight puzzle and gridworlds) are Eulerian, they cannot be used to distinguish between efficient and inefficient real-time search algorithms. It follows that one has to use non-Eulerian domains to demonstrate the general superiority of a given algorithm. To this end, we present two classes of hard-to-search state spaces and demonstrate the performance of various real-time search algorithms on them.

  17. Bonds Between Atoms.

    ERIC Educational Resources Information Center

    Holden, Alan

    The field of inquiry into how atoms are bonded together to form molecules and solids crosses the borderlines between physics and chemistry encompassing methods characteristic of both sciences. At one extreme, the inquiry is pursued with care and rigor into the simplest cases; at the other extreme, suggestions derived from the more careful inquiry…

  18. Dialogic Bonds and Boundaries.

    ERIC Educational Resources Information Center

    Khawaja, Mabel

    A study of literature cannot be divorced from cultural contexts, nor can it ignore the humanist vision in interpreting literary texts. To discover dialogic bonds and boundaries between the reader and the text, or the writer and the audience, English classes should have two objectives: (1) to explore the diversity of perspectives, and (2) to relate…

  19. Photochemical tissue bonding

    DOEpatents

    Redmond, Robert W.; Kochevar, Irene E.

    2012-01-10

    Photochemical tissue bonding methods include the application of a photosensitizer to a tissue and/or tissue graft, followed by irradiation with electromagnetic energy to produce a tissue seal. The methods are useful for tissue adhesion, such as in wound closure, tissue grafting, skin grafting, musculoskeletal tissue repair, ligament or tendon repair and corneal repair.

  20. Bonding without Tears.

    ERIC Educational Resources Information Center

    Akeroyd, F. Michael

    1982-01-01

    Discusses merits of using sigma-pi model of ethylene as a teaching aid in introductory organic chemistry. The nonmathematical treatment of sigma-pi bonding is then extended to such phenomena as conjugation, hyperconjugation, Markovnikoff addition, aromaticity, and aromatic substitution. (SK)

  1. GRAPHITE BONDING METHOD

    DOEpatents

    King, L.D.P.

    1964-02-25

    A process for bonding or joining graphite members together in which a thin platinum foil is placed between the members, heated in an inert atmosphere to a temperature of 1800 deg C, and then cooled to room temperature is described. (AEC)

  2. Bonding with the Past.

    ERIC Educational Resources Information Center

    Common Ground: Archeology and Ethnography in the Public Interest, 1998

    1998-01-01

    An interview with Linda Mayro, archaeologist and cultural resources manager for Pima County, Arizona, discusses efforts of local groups to preserve local Native-American and Mexican cultural-heritage sites in oppositon to commercial land developers. A public information campaign led to passage of a $6.4 million historic preservation bond. (SAS)

  3. Athermal fracture of covalent bonds

    SciTech Connect

    Gilman, J.J.

    1999-08-01

    Most fracture is athermal. Either because it occurs at low temperatures or because it occurs too fast for thermal activation to be effective. Thus it must be directly activated by applied stresses. This can occur via quantum tunneling when the chemical bonding of a solid resides in localized (covalent) bonds. Then applied stresses can cause the bonding electrons to become delocalized (anti-bonded) through quantum tunneling. That is, the bonds become broken. The process is related to the Zener tunneling process that is thought to be responsible for dielectric breakdown in semiconductors. Under a driving force, bonding electrons tunnel at constant energy from their bonding states into anti-bonding states through the forbidden gap in the bonding energy spectrum.

  4. 27 CFR 24.147 - Operations bond or unit bond.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... or contiguous distilled spirits plant qualified under 27 CFR part 19 for the production of distilled... amended, give an operations bond or unit bond in accordance with the applicable provisions of 27 CFR part... BUREAU, DEPARTMENT OF THE TREASURY LIQUORS WINE Establishment and Operations Bonds and Consents of...

  5. How a Community Decides to Issue Bonds. Municipal Bonds Series.

    ERIC Educational Resources Information Center

    Wandschneider, Philip; And Others

    Intended for local municipal officials and their advisors on public finance issues, this publication describes the legal environment surrounding bonds and examines some of the factors affecting the political feasibility of bond issues. Four categories of state controls of municipal bonds are discussed: limits on the amount of debt municipalities…

  6. Shear bond strength of one-step self-etch adhesives: pH influence

    PubMed Central

    Poggio, Claudio; Beltrami, Riccardo; Scribante, Andrea; Colombo, Marco; Chiesa, Marco

    2015-01-01

    Background: The aim of this study was to compare the shear bond strength of four one-step self-etch adhesives with different pH values to enamel and dentin. Materials and Methods: In this in vitro study, 200 bovine permanent mandibular incisors were used. Four one-step self-etch adhesives with different pH values were tested both on enamel and on dentin: Adper™ Easy Bond Self-Etch Adhesive (pH = 0.8-1), Futurabond NR (pH=2), G-aenial Bond (pH = 1.5), Clearfil S3 Bond (pH = 2.7). After adhesive systems application, a nanohybrid composite resin was inserted into the bonded surface. The specimens were placed in a universal testing machine. The shear bond strength was performed at a cross-head speed of 1 mm/min until the sample rupture. The shear bond strength values (MPa) of the different groups were compared with analysis of variance after that Kolmogorov and Smirnov tests were applied to assess normality of distributions. P < 0.05 was considered as significant. Results: In enamel shear bond strength, the highest shear bond strength values were reported with Futurabond NR (P < 0.01); however, no significant differences were found with Clearfil S3 Bond. The others adhesive systems showed lower shear bond strength values with significant differences between them (P < 0.05). When comparing the dentin shear bond strength, the lowest shear bond strength values were reported with Clearfil S3 Bond (P < 0.05), while there were no significant differences among the other three products (P > 0.05). Conclusion: The pH values of adhesive systems did not influence significantly their shear bond strength to enamel or dentin. PMID:26005459

  7. IMPROVED BONDING METHOD

    DOEpatents

    Padgett, E.V. Jr.; Warf, D.H.

    1964-04-28

    An improved process of bonding aluminum to aluminum without fusion by ultrasonic vibrations plus pressure is described. The surfaces to be bonded are coated with an aqueous solution of alkali metal stearate prior to assembling for bonding. (AEC) O H19504 Present information is reviewed on steady state proliferation, differentiation, and maturation of blood cells in mammals. Data are cited from metabolic tracer studies, autoradiographic studies, cytologic studies, studies of hematopoietic response to radiation injuries, and computer analyses of blood cell production. A 3-step model for erythropoiesis and a model for granulocyte kinetics are presented. New approaches to the study of lymphocytopoiesis described include extracorporeal blood irradiation to deplete lymphocytic tissue without direct injury to the formative tissues as a means to study the stressed system, function control, and rates of proliferation. It is pointed out that present knowledge indicates that lymphocytes comprise a mixed family, with diverse life spans, functions, and migration patterns with apparent aimless recycling from modes to lymph to blood to nodes that has not yet been quantitated. Areas of future research are postulated. (70 references.) (C.H.)

  8. Disulfide bonds of acetylcholinesterase

    SciTech Connect

    MacPhee-Quigley, K.; Vedvick, T.; Taylor, P.; Taylor, S.

    1986-05-01

    The positions of the inter- and intrasubunit disulfide bridges were established for the 11S form of acetylcholinesterase (AChE) isolated from Torpedo californica. A major form of AChE localized within the basal lamina of the synapse is a dimensionally asymmetric molecule which contains either two (13S) or three (17S) sets of catalytic subunits linked to collagenous and non-collagenous structural subunits. Limited proteolysis yields a tetramer of catalytic subunits which sediments at 11S. Each catalytic subunit contains 8 cysteine residues. Initially, these Cys residues were identified following trypsin digestion of the reduced protein alkylated with (/sup 14/C)-iodoacetate. Peptides were resolved by gel filtration followed by reverse phase HPLC. To determine the disulfide bonding profile, native non-reduced 11S AChE was treated with a fluorescent, sulfhydryl-specific reagent, monobromobimane, prior to proteolytic digestion. One fluorescent Cys peptide was identified indicating that a single sulfhydryl residue was present in its reduced form. Three pairs of disulfide bonded peptides were identified, sequenced, and localized in the polypeptide chain. The Cys residue that is located in the C-terminal tryptic peptide was disulfide bonded to an identical peptide and thus forms the intersubunit crosslink. Finally, the cysteine positions have been compared with the sequence of the homologous protein, thyroglobulin. Both likely share a common pattern of folding.

  9. Cooperativity in Tetrel Bonds.

    PubMed

    Marín-Luna, Marta; Alkorta, Ibon; Elguero, José

    2016-02-01

    A theoretical study of the cooperativity in linear chains of (H3SiCN)n and (H3SiNC)n complexes connected by tetrel bonds has been carried out by means of MP2 and CCSD(T) computational methods. In all cases, a favorable cooperativity is observed, especially in some of the largest linear chains of (H3SiNC)n, where the effect is so large that the SiH3 group is almost equidistant to the two surrounding CN groups and it becomes planar. In addition, the combination of tetrel bonds with other weak interactions (halogen, chalcogen, pnicogen, triel, beryllium, lithium, and hydrogen bond) has been explored using ternary complexes, (H3SiCN)2:XY and (H3SiNC)2:XY. In all cases, positive cooperativity is obtained, especially in the (H3SiNC)2:ClF and (H3SiNC)2:SHF ternary complexes, where, respectively, halogen and chalcogen shared complexes are formed. PMID:26756083

  10. Direct bonded space maintainers.

    PubMed

    Santos, V L; Almeida, M A; Mello, H S; Keith, O

    1993-01-01

    The aim of this study was to evaluate clinically a bonded space maintainer, which would reduce chair-side time and cost. Sixty appliances were fabricated from 0.7 mm stainless steel round wire and bonded using light-cured composite to the two teeth adjacent to the site of extraction of a posterior primary tooth. Twenty males and sixteen females (age range 5-9-years-old) were selected from the Pedodontic clinic of the State University of Rio de Janeiro. The sixty space maintainers were divided into two groups according to the site in which they were placed: a) absent first primary molar and b) absent second primary molar. Impressions and study models were obtained prior to and 6 months after bonding the appliances. During this period only 8.3% of failures were observed, most of them from occlusal or facial trauma. Student t-test did not show statistically significant alterations in the sizes of the maintained spaces during the trial period.

  11. The IBA Easy-E-Beam™ Integrated Processing System

    NASA Astrophysics Data System (ADS)

    Cleland, Marshall R.; Galloway, Richard A.; Lisanti, Thomas F.

    2011-06-01

    IBA Industrial Inc., (formerly known as Radiation Dynamics, Inc.) has been making high-energy and medium-energy, direct-current proton and electron accelerators for research and industrial applications for many years. Some industrial applications of high-power electron accelerators are the crosslinking of polymeric materials and products, such as the insulation on electrical wires, multi-conductor cable jackets, heat-shrinkable plastic tubing and film, plastic pipe, foam and pellets, the partial curing of rubber sheet for automobile tire components, and the sterilization of disposable medical devices. The curing (polymerization and crosslinking) of carbon and glass fiber-reinforced composite plastic parts, the preservation of foods and the treatment of waste materials are attractive possibilities for future applications. With electron energies above 1.0 MeV, the radiation protection for operating personnel is usually provided by surrounding the accelerator facility with thick concrete walls. With lower energies, steel and lead panels can be used, which are substantially thinner and more compact than the equivalent concrete walls. IBA has developed a series of electron processing systems called Easy-e-Beam™ for the medium energy range from 300 keV to 1000 keV. These systems include the shielding as an integral part of a complete radiation processing facility. The basic concepts of the electron accelerator, the product processing equipment, the programmable control system, the configuration of the radiation shielding and some performance characteristics are described in this paper.

  12. Growing perovskite into polymers for easy-processable optoelectronic devices

    NASA Astrophysics Data System (ADS)

    Masi, Sofia; Colella, Silvia; Listorti, Andrea; Roiati, Vittoria; Liscio, Andrea; Palermo, Vincenzo; Rizzo, Aurora; Gigli, Giuseppe

    2015-01-01

    Here we conceive an innovative nanocomposite to endow hybrid perovskites with the easy processability of polymers, providing a tool to control film quality and material crystallinity. We verify that the employed semiconducting polymer, poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV), controls the self-assembly of CH3NH3PbI3 (MAPbI3) crystalline domains and favors the deposition of a very smooth and homogenous layer in one straightforward step. This idea offers a new paradigm for the implementation of polymer/perovskite nanocomposites towards versatile optoelectronic devices combined with the feasibility of mass production. As a proof-of-concept we propose the application of such nanocomposite in polymer solar cell architecture, demonstrating a power conversion efficiency up to 3%, to date the highest reported for MEH-PPV. On-purpose designed polymers are expected to suit the nanocomposite properties for the integration in diverse optoelectronic devices via facile processing condition.

  13. Growing perovskite into polymers for easy-processable optoelectronic devices

    PubMed Central

    Masi, Sofia; Colella, Silvia; Listorti, Andrea; Roiati, Vittoria; Liscio, Andrea; Palermo, Vincenzo; Rizzo, Aurora; Gigli, Giuseppe

    2015-01-01

    Here we conceive an innovative nanocomposite to endow hybrid perovskites with the easy processability of polymers, providing a tool to control film quality and material crystallinity. We verify that the employed semiconducting polymer, poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV), controls the self-assembly of CH3NH3PbI3 (MAPbI3) crystalline domains and favors the deposition of a very smooth and homogenous layer in one straightforward step. This idea offers a new paradigm for the implementation of polymer/perovskite nanocomposites towards versatile optoelectronic devices combined with the feasibility of mass production. As a proof-of-concept we propose the application of such nanocomposite in polymer solar cell architecture, demonstrating a power conversion efficiency up to 3%, to date the highest reported for MEH-PPV. On-purpose designed polymers are expected to suit the nanocomposite properties for the integration in diverse optoelectronic devices via facile processing condition. PMID:25579988

  14. An easy-to-use diagnostic system development shell

    NASA Technical Reports Server (NTRS)

    Tsai, L. C.; Ross, J. B.; Han, C. Y.; Wee, W. G.

    1987-01-01

    The Diagnostic System Development Shell (DSDS), an expert system development shell for diagnostic systems, is described. The major objective of building the DSDS is to create a very easy to use and friendly environment for knowledge engineers and end-users. The DSDS is written in OPS5 and CommonLisp. It runs on a VAX/VMS system. A set of domain independent, generalized rules is built in the DSDS, so the users need not be concerned about building the rules. The facts are explicitly represented in a unified format. A powerful check facility which helps the user to check the errors in the created knowledge bases is provided. A judgement facility and other useful facilities are also available. A diagnostic system based on the DSDS system is question driven and can call or be called by other knowledge based systems written in OPS5 and CommonLisp. A prototype diagnostic system for diagnosing a Philips constant potential X-ray system has been built using the DSDS.

  15. The IBA Easy-E-Beam Integrated Processing System

    SciTech Connect

    Cleland, Marshall R.; Galloway, Richard A.; Lisanti, Thomas F.

    2011-06-01

    IBA Industrial Inc., (formerly known as Radiation Dynamics, Inc.) has been making high-energy and medium-energy, direct-current proton and electron accelerators for research and industrial applications for many years. Some industrial applications of high-power electron accelerators are the crosslinking of polymeric materials and products, such as the insulation on electrical wires, multi-conductor cable jackets, heat-shrinkable plastic tubing and film, plastic pipe, foam and pellets, the partial curing of rubber sheet for automobile tire components, and the sterilization of disposable medical devices. The curing (polymerization and crosslinking) of carbon and glass fiber-reinforced composite plastic parts, the preservation of foods and the treatment of waste materials are attractive possibilities for future applications. With electron energies above 1.0 MeV, the radiation protection for operating personnel is usually provided by surrounding the accelerator facility with thick concrete walls. With lower energies, steel and lead panels can be used, which are substantially thinner and more compact than the equivalent concrete walls. IBA has developed a series of electron processing systems called Easy-e-Beam for the medium energy range from 300 keV to 1000 keV. These systems include the shielding as an integral part of a complete radiation processing facility. The basic concepts of the electron accelerator, the product processing equipment, the programmable control system, the configuration of the radiation shielding and some performance characteristics are described in this paper.

  16. Easy Long-Term Identifiers and the "Data Paper"

    NASA Astrophysics Data System (ADS)

    Kunze, John

    2011-05-01

    A new publishing paradigm is needed to cope with the deluge of data artifacts produced by data-intensive science, many of which are vital to data re-use and verification of published scientific conclusions. Due to the limitations of traditional publishing, most of these artifacts are not usually disseminated, cited, or preserved. At the California Digital Library (CDL), one promising approach to the problem is to wrap these artifacts in the metaphor of a "data paper", assigning and managing data citations with our EZID (easy-eye-dee) identifier service. A data paper is a somewhat unfamiliar bundle of scholarly output with a familiar facade: minimally, a set of links to archived artifacts and a cover sheet containing familiar elements such as title, authors, date, abstract, and persistent identifier _ just enough to create basic citations, build "overlay journals", and enable discovery of data by internet search engines. Over time, we expect to add elements that permit deeper domain-specific discovery and re-use, such as variable names, methods, etc. At the same time, for data and identifiers that we manage, we will leverage as much domain-agnosticism data and identifier as possible.

  17. Easy and effective virtual tour on the World Wide Web

    NASA Astrophysics Data System (ADS)

    Yoon, Ilmi; Kang, Andrew; Roberts, John; Yoon, Sanghyuk

    2005-01-01

    Web-based Virtual Tour has become a desirable and demanded application, yet challenging due to the nature of web application's running environment such as limited bandwidth and no guarantee of high computation power on the client side. Image-based rendering approach has attractive advantages over traditional 3D rendering approach in such Web Applications. Traditional geometry-based approach, such as VRML, requires labor-intensive 3D modeling process, high bandwidth and computation power especially for photo-realistic virtual scenes. QuickTime VR and IPIX as examples of image-based approach, use panoramic photos and the virtual scenes that can be generated from photos directly skipping the modeling process. But, QuickTime VR and IPIX may not only require special cameras or effort to take panoramic views but also provide only one fixed-point navigation (look-around and zooming in-out) rather than "walk around", that is a very important feature to provide immersive experience to virtual tourists. Easy and Effective Virtual Tour constructs virtual tour using several snap shots of conventional photos without special tools, build simple 3D space within each photo using spidery mesh, and expand the virtual spaces by connecting each other using simple user intervention to specify correspondence. The expanded virtual space provides virtual tourists with free navigation and immersive experience of walking around through the WWW.

  18. Easy and effective virtual tour on the World Wide Web

    NASA Astrophysics Data System (ADS)

    Yoon, Ilmi; Kang, Andrew; Roberts, John; Yoon, Sanghyuk

    2004-12-01

    Web-based Virtual Tour has become a desirable and demanded application, yet challenging due to the nature of web application"s running environment such as limited bandwidth and no guarantee of high computation power on the client side. Image-based rendering approach has attractive advantages over traditional 3D rendering approach in such Web Applications. Traditional geometry-based approach, such as VRML, requires labor-intensive 3D modeling process, high bandwidth and computation power especially for photo-realistic virtual scenes. QuickTime VR and IPIX as examples of image-based approach, use panoramic photos and the virtual scenes that can be generated from photos directly skipping the modeling process. But, QuickTime VR and IPIX may not only require special cameras or effort to take panoramic views but also provide only one fixed-point navigation (look-around and zooming in-out) rather than `walk around", that is a very important feature to provide immersive experience to virtual tourists. Easy and Effective Virtual Tour constructs virtual tour using several snap shots of conventional photos without special tools, build simple 3D space within each photo using spidery mesh, and expand the virtual spaces by connecting each other using simple user intervention to specify correspondence. The expanded virtual space provides virtual tourists with free navigation and immersive experience of walking around through the WWW.

  19. 46 CFR Sec. 10 - Bonds.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 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...

  20. 46 CFR Sec. 10 - Bonds.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 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...

  1. 46 CFR Sec. 10 - Bonds.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 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...

  2. 46 CFR Sec. 10 - Bonds.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 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...

  3. Coulombic Models in Chemical Bonding.

    ERIC Educational Resources Information Center

    Sacks, Lawrence J.

    1986-01-01

    Compares the coulumbic point charge model for hydrogen chloride with the valence bond model. It is not possible to assign either a nonpolar or ionic canonical form of the valence bond model, while the covalent-ionic bond distribution does conform to the point charge model. (JM)

  4. Hydrogen bonding in ionic liquids.

    PubMed

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

    2015-03-01

    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

  5. J-Earth: Remote Sensing Analysis Made Easy

    NASA Astrophysics Data System (ADS)

    Dickenshied, S.; Christensen, P. R.; Prashad, L. C.; Noss, D.; Anwar, S.; Cheeseman, S.; Dunn, S.; Rupp, J.

    2011-12-01

    A wealth of terrestrial remote sensing data has been collected and made public over the years from a variety of missions, but accessing this data and performing analysis on it has often been a time consuming and problematic task. J-Earth is a geospatial application that provides a quick and consistent means of accessing many terrestrial datasets which can then be analyzed and compared with each other. In addition to providing direct access to a number of preprocessed products based off of MODIS, ASTER, and TIMS datasets, J-Earth also makes it easy for a user to import their own data and work with it in an identical fashion. Users can easily work with both graphical and numeric datasets as well as vector/shapefile data. Numeric data can be viewed for a particular location through multiple datasets or plotted across an arbitrary profile line. Shapes can be used to find intersections with other shapefiles or to perform analytical calculations (mean, max, min, etc) upon numeric data within the bounds of a shape. These tools allow a user to quickly assess the geologic parameters of the area, including mineralogy, chemistry, surface temperature, topography and elevation. Additionally, J-Earth allows for temporal comparisons of regions for instruments which have repeat coverage over multiple years. J-Earth is part of the JMARS (Java Mission-planning and Analysis for Remote Sensing) suite of geospatial applications developed by the Mars Space Flight Facility at Arizona State University. This suite of software is used for mission planning and scientific data analysis by active NASA missions to Mars, the Moon, and Vesta. It is used by scientists, researchers and students of all ages from more than 40 countries around the world.

  6. Multimodality image integration for radiotherapy treatment: an easy approach

    NASA Astrophysics Data System (ADS)

    Santos, Andres; Pascau, Javier; Desco, Manuel; Santos, Juan A.; Calvo, Felipe A.; Benito, Carlos; Garcia-Barreno, Rafael

    2001-05-01

    The interest of using combined MR and CT information for radiotherapy planning is well documented. However, many planning workstations do not allow to use MR images, nor import predefined contours. This paper presents a new simple approach for transferring segmentation results from MRI to a CT image that will be used for radiotherapy planning, using the same original CT format. CT and MRI images of the same anatomical area are registered using mutual information (MI) algorithm. Targets and organs at risk are segmented by the physician on the MR image, where their contours are easy to track. A locally developed software running on PC is used for this step, with several facilities for the segmentation process. The result is transferred onto the CT by slightly modifying up and down the original Hounsfield values of some points of the contour. This is enough to visualize the contour on the CT, but does not affect dose calculations. The CT is then stored using the original file format of the radiotherapy planning workstation, where the technician uses the segmented contour to design the correct beam positioning. The described method has been tested in five patients. Simulations and patient results show that the dose distribution is not affected by the small modification of pixels of the CT image, while the segmented structures can be tracked in the radiotherapy planning workstation-using adequate window/level settings. The presence of the physician is not requires at the planning workstation, and he/she can perform the segmentation process using his/her own PC. This new approach makes it possible to take advantage from the anatomical information present on the MRI and to transfer the segmentation to the CT used for planning, even when the planning workstation does not allow to import external contours. The physician can draw the limits of the target and areas at risk off-line, thus separating in time the segmentation and planning tasks and increasing the efficiency.

  7. 26 CFR 1.144-1 - Qualified small issue bonds, qualified student loan bonds, and qualified redevelopment bonds.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... student loan bonds, and qualified redevelopment bonds. (a) Overview. Interest on a private activity bond... 26 Internal Revenue 2 2010-04-01 2010-04-01 false Qualified small issue bonds, qualified student loan bonds, and qualified redevelopment bonds. 1.144-1 Section 1.144-1 Internal Revenue...

  8. 26 CFR 1.144-1 - Qualified small issue bonds, qualified student loan bonds, and qualified redevelopment bonds.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... student loan bonds, and qualified redevelopment bonds. (a) Overview. Interest on a private activity bond... 26 Internal Revenue 2 2012-04-01 2012-04-01 false Qualified small issue bonds, qualified student loan bonds, and qualified redevelopment bonds. 1.144-1 Section 1.144-1 Internal Revenue...

  9. 26 CFR 1.144-1 - Qualified small issue bonds, qualified student loan bonds, and qualified redevelopment bonds.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... student loan bonds, and qualified redevelopment bonds. (a) Overview. Interest on a private activity bond... 26 Internal Revenue 2 2014-04-01 2014-04-01 false Qualified small issue bonds, qualified student loan bonds, and qualified redevelopment bonds. 1.144-1 Section 1.144-1 Internal Revenue...

  10. 26 CFR 1.144-1 - Qualified small issue bonds, qualified student loan bonds, and qualified redevelopment bonds.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... student loan bonds, and qualified redevelopment bonds. (a) Overview. Interest on a private activity bond... 26 Internal Revenue 2 2011-04-01 2011-04-01 false Qualified small issue bonds, qualified student loan bonds, and qualified redevelopment bonds. 1.144-1 Section 1.144-1 Internal Revenue...

  11. 26 CFR 1.144-1 - Qualified small issue bonds, qualified student loan bonds, and qualified redevelopment bonds.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... student loan bonds, and qualified redevelopment bonds. (a) Overview. Interest on a private activity bond... 26 Internal Revenue 2 2013-04-01 2013-04-01 false Qualified small issue bonds, qualified student loan bonds, and qualified redevelopment bonds. 1.144-1 Section 1.144-1 Internal Revenue...

  12. Influence of spherical assembly of copper ferrite nanoparticles on magnetic properties: orientation of magnetic easy axis.

    PubMed

    Chatterjee, Biplab K; Bhattacharjee, Kaustav; Dey, Abhishek; Ghosh, Chandan K; Chattopadhyay, Kalyan K

    2014-06-01

    The magnetic properties of copper ferrite (CuFe2O4) nanoparticles prepared via sol-gel auto combustion and facile solvothermal method are studied focusing on the effect of nanoparticle arrangement. Randomly oriented CuFe2O4 nanoparticles (NP) are obtained from the sol-gel auto combustion method, while the solvothermal method allows us to prepare iso-oriented uniform spherical ensembles of CuFe2O4 nanoparticles (NS). X-ray diffractometry (XRD), atomic absorption spectroscopy (AAS), infra-red (IR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), (57)Fe Mössbauer spectroscopy and vibrating sample magnetometer (VSM) are used to investigate the composition, microstructure and magnetic properties of as-prepared ferrite nanoparticles. The field-dependent magnetization measurement for the NS sample at low temperature exhibits a step-like rectangular hysteresis loop (M(R)/M(S) ~ 1), suggesting cubic anisotropy in the system, whereas for the NP sample, typical features of uniaxial anisotropy (M(R)/M(S) ~ 0.5) are observed. The coercive field (HC) for the NS sample shows anomalous temperature dependence, which is correlated with the variation of effective anisotropy (K(E)) of the system. A high-temperature enhancement of H(C) and K(E) for the NS sample coincides with a strong spin-orbit coupling in the sample as evidenced by significant modification of Cu/Fe-O bond distances. The spherical arrangement of nanocrystals at mesoscopic scale provokes a high degree of alignment of the magnetic easy axis along the applied field leading to a step-like rectangular hysteresis loop. A detailed study on the temperature dependence of magnetic anisotropy of the system is carried out, emphasizing the influence of the formation of spherical iso-oriented assemblies. PMID:24714977

  13. On homogeneous L-bonds and heterogeneous L-bonds

    NASA Astrophysics Data System (ADS)

    Konecny, Jan; Ojeda-Aciego, Manuel

    2016-02-01

    In this paper, we deal with suitable generalizations of the notion of bond between contexts, as part of the research area of Formal Concept Analysis. We study different generalizations of the notion of bond within the ? -fuzzy setting. Specifically, given a formal context, there are three prototypical pairs of concept-forming operators, and this immediately leads to three possible versions of the notion of bond (so-called homogeneous bond wrt certain pair of concept-forming operators). The first results show a close correspondence between a homogeneous bond between two contexts and certain special types of mappings between the sets of extents (or intents) of the corresponding concept lattices. Later, we introduce the so-called heterogeneous bonds (considering simultaneously two types of concept-forming operators) and generalize the previous relationship to mappings between the sets of extents (or intents) of the corresponding concept lattices.

  14. Valence bond cluster studies of alkali metal/semiconductor bonding

    NASA Astrophysics Data System (ADS)

    Tatar, Robert C.; Messmer, Richard P.

    1986-12-01

    We present results of cluster studies of alkali metal/semiconductor bonding. Using the Generalized Valence Bond (GVB) method, we find a remarkable consistency in the behavoir of bonding orbitals for a variety of systems, including: LiH, CLi4, LiH4 and several hypervalent systems, such as SiH3Li2, SiH4Li2. Our results show that the metal-semiconductor bonding in these systems can be understood in terms of a pairing between McAdon-Goddard type metallic bonding orbitals and a set of equivalent orbitals of the non-metallic species. We propose that the results are relevant to the initial stages of alkali overlayer growth on semiconductor surfaces and lead to a simple picture of the bonding including the transition from a non-conducting to a conducting layer. We have considered numerous proposed hypervalent structures in light of the above results and find that they can be understood.

  15. Bond strength with custom base indirect bonding techniques.

    PubMed

    Klocke, Arndt; Shi, Jianmin; Kahl-Nieke, Bärbel; Bismayer, Ulrich

    2003-04-01

    Different types of adhesives for indirect bonding techniques have been introduced recently. But there is limited information regarding bond strength with these new materials. In this in vitro investigation, stainless steel brackets were bonded to 100 permanent bovine incisors using the Thomas technique, the modified Thomas technique, and light-cured direct bonding for a control group. The following five groups of 20 teeth each were formed: (1) modified Thomas technique with thermally cured base composite (Therma Cure) and chemically cured sealant (Maximum Cure), (2) Thomas technique with thermally cured base composite (Therma Cure) and chemically cured sealant (Custom I Q), (3) Thomas technique with light-cured base composite (Transbond XT) and chemically cured sealant (Sondhi Rapid Set), (4) modified Thomas technique with chemically cured base adhesive (Phase II) and chemically cured sealant (Maximum Cure), and (5) control group directly bonded with light-cured adhesive (Transbond XT). Mean bond strengths in groups 3, 4, and 5 were 14.99 +/- 2.85, 15.41 +/- 3.21, and 13.88 +/- 2.33 MPa, respectively, and these groups were not significantly different from each other. Groups 1 (mean bond strength 7.28 +/- 4.88 MPa) and 2 (mean bond strength 7.07 +/- 4.11 MPa) showed significantly lower bond strengths than groups 3, 4, and 5 and a higher probability of bond failure. Both the original (group 2) and the modified (group 1) Thomas technique were able to achieve bond strengths comparable to the light-cured direct bonded control group.

  16. Modulating the strength of tetrel bonding through beryllium bonding.

    PubMed

    Liu, Mingxiu; Yang, Li; Li, Qingzhong; Li, Wenzuo; Cheng, Jianbo; Xiao, Bo; Yu, Xuefang

    2016-08-01

    Quantum chemical calculations were performed to investigate the stability of the ternary complexes BeH2···XMH3···NH3 (X = F, Cl, and Br; M = C, Si, and Ge) and the corresponding binary complexes at the atomic level. Our results reveal that the stability of the XMH3···BeH2 complexes is mainly due to both a strong beryllium bond and a weak tetrel-hydride interaction, while the XMH3···NH3 complexes are stabilized by a tetrel bond. The beryllium bond with a halogen atom as the electron donor has many features in common with a beryllium bond with an O or N atom as the electron donor, although they do exhibit some different characteristics. The stability of the XMH3···NH3 complex is dominated by the electrostatic interaction, while the orbital interaction also makes an important contribution. Interestingly, as the identities of the X and M atoms are varied, the strength of the tetrel bond fluctuates in an irregular manner, which can explained by changes in electrostatic potentials and orbital interactions. In the ternary systems, both the beryllium bond and the tetrel bond are enhanced, which is mainly ascribed to increased electrostatic potentials on the corresponding atoms and charge transfer. In particular, when compared to the strengths of the tetrel and beryllium bonds in the binary systems, in the ternary systems the tetrel bond is enhanced to a greater degree than the beryllium bond. Graphical Abstract A tetrel bond can be strengthened greatly by a beryllium bond. PMID:27464738

  17. Modulating the strength of tetrel bonding through beryllium bonding.

    PubMed

    Liu, Mingxiu; Yang, Li; Li, Qingzhong; Li, Wenzuo; Cheng, Jianbo; Xiao, Bo; Yu, Xuefang

    2016-08-01

    Quantum chemical calculations were performed to investigate the stability of the ternary complexes BeH2···XMH3···NH3 (X = F, Cl, and Br; M = C, Si, and Ge) and the corresponding binary complexes at the atomic level. Our results reveal that the stability of the XMH3···BeH2 complexes is mainly due to both a strong beryllium bond and a weak tetrel-hydride interaction, while the XMH3···NH3 complexes are stabilized by a tetrel bond. The beryllium bond with a halogen atom as the electron donor has many features in common with a beryllium bond with an O or N atom as the electron donor, although they do exhibit some different characteristics. The stability of the XMH3···NH3 complex is dominated by the electrostatic interaction, while the orbital interaction also makes an important contribution. Interestingly, as the identities of the X and M atoms are varied, the strength of the tetrel bond fluctuates in an irregular manner, which can explained by changes in electrostatic potentials and orbital interactions. In the ternary systems, both the beryllium bond and the tetrel bond are enhanced, which is mainly ascribed to increased electrostatic potentials on the corresponding atoms and charge transfer. In particular, when compared to the strengths of the tetrel and beryllium bonds in the binary systems, in the ternary systems the tetrel bond is enhanced to a greater degree than the beryllium bond. Graphical Abstract A tetrel bond can be strengthened greatly by a beryllium bond.

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

    DOEpatents

    Beavis, L.C.; Karnowsky, M.M.; Yost, F.G.

    1992-06-16

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

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

    DOEpatents

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

    1992-01-01

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

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

    SciTech Connect

    Beavis, L.C.; Karnowsky, M.M.; Yost, F.G.

    1990-12-31

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

  1. Orthogonal Synthesis of "Easy-to-Read" Information-Containing Polymers Using Phosphoramidite and Radical Coupling Steps.

    PubMed

    Cavallo, Gianni; Al Ouahabi, Abdelaziz; Oswald, Laurence; Charles, Laurence; Lutz, Jean-François

    2016-08-01

    A new orthogonal solid-phase iterative strategy is proposed for the synthesis of sequence-coded polymers. This approach relies on the use of two successive chemoselective steps: (i) phosphoramidite coupling, and (ii) radical-radical coupling. These repeated steps can be performed using two different types of building blocks, i.e. a phosphoramidite monomer that also contains an alkyl bromide and a hydroxy-functionalized nitroxide. The phosphoramidite and the hydroxy group are reacted in step (i), thus leading to a phosphite that is oxidized in situ into a phosphate bond. The alkyl bromide is activated by copper bromide in step (ii) to afford a carbon-centered radical that is spin-trapped in situ by the nitroxide. The iterative repetition of these steps allow synthesis of uniform polymers, as evidenced by high-resolution electrospray mass spectrometry. Moreover, binary information could be easily implemented in the polymers using different types of phosphoramidite monomers in step (i). Interestingly, it was found that the formed information-containing polymers are very easy to sequence by tandem mass spectrometry due to the presence of easily cleavable alkoxyamine bonds formed in step (ii). PMID:27454229

  2. 27 CFR 28.66 - Strengthening bonds.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... bonds. In all cases where the penal sum of any bond becomes insufficient, the principal shall either give a strengthening bond with the same surety to attain a sufficient penal sum, or give a new bond to... of any bond to less than its full penal sum. Strengthening bonds shall show the current date...

  3. Bond Sensitivity to Silicone Contamination

    NASA Technical Reports Server (NTRS)

    Caldwell, G. A.; Hudson, W. D.; Hudson, W. D.; Cash, Stephen F. (Technical Monitor)

    2003-01-01

    Currently during fabrication of the Space Shuttle booster rocket motors, the use of silicone and silicone-containing products is prohibited in most applications. Many shop aids and other materials containing silicone have the potential, if they make contact with a bond surface, to transfer some of the silicone to the substrates being bonded. Such transfer could result in a reduction of the bond strength or even failure of the subsequent bonds. This concern is driving the need to understand the effect of silicones and the concentration needed to affect a given bond-line strength. Additionally, as silicone detection methods used for materials acceptance improve what may have gone unnoticed earlier is now being detected. Thus, realistic silicone limits for process materials (below which bond performance is satisfactory) are needed rather than having an absolute no silicone permitted policy.

  4. Better Bonded Ethernet Load Balancing

    SciTech Connect

    Gabler, Jason

    2006-09-29

    When a High Performance Storage System's mover shuttles large amounts of data to storage over a single Ethernet device that single channel can rapidly become saturated. Using Linux Ethernet channel bonding to address this and similar situations was not, until now, a viable solution. The various modes in which channel bonding could be configured always offered some benefit but only under strict conditions or at a system resource cost that was greater than the benefit gained by using channel bonding. Newer bonding modes designed by various networking hardware companies, helpful in such networking scenarios, were already present in their own switches. However, Linux-based systems were unable to take advantage of those new modes as they had not yet been implemented in the Linux kernel bonding driver. So, except for basic fault tolerance, Linux channel bonding could not positively combine separate Ethernet devices to provide the necessary bandwidth.

  5. Food quality and authenticity screening via easy ambient sonic-spray ionization mass spectrometry.

    PubMed

    Porcari, Andreia M; Fernandes, Gabriel D; Barrera-Arellano, Daniel; Eberlin, Marcos N; Alberici, Rosana M

    2016-02-21

    This review is the first to summarize a decade of studies testing the use of easy ambient sonic-spray ionization mass spectrometry (EASI-MS) and its several sister techniques, Venturi (V-EASI), thermal imprinting (TI-EASI) and Spartan (S-EASI) mass spectrometry in food quality control and authentication. Since minimal or no sample preparation is required, such ambient desorption/ionization techniques have been shown to provide direct, fast and selective fingerprinting characterization at the molecular level based on the pools of the most typical components. They have also been found to be applicable on intact, undisturbed samples or on simple solvent extracts. Fundamentals of EASI-MS and its sister techniques, including mechanisms, devices, parameters and strategies, as well as the many applications reported for food analysis, are summarized and discussed.

  6. Food quality and authenticity screening via easy ambient sonic-spray ionization mass spectrometry.

    PubMed

    Porcari, Andreia M; Fernandes, Gabriel D; Barrera-Arellano, Daniel; Eberlin, Marcos N; Alberici, Rosana M

    2016-02-21

    This review is the first to summarize a decade of studies testing the use of easy ambient sonic-spray ionization mass spectrometry (EASI-MS) and its several sister techniques, Venturi (V-EASI), thermal imprinting (TI-EASI) and Spartan (S-EASI) mass spectrometry in food quality control and authentication. Since minimal or no sample preparation is required, such ambient desorption/ionization techniques have been shown to provide direct, fast and selective fingerprinting characterization at the molecular level based on the pools of the most typical components. They have also been found to be applicable on intact, undisturbed samples or on simple solvent extracts. Fundamentals of EASI-MS and its sister techniques, including mechanisms, devices, parameters and strategies, as well as the many applications reported for food analysis, are summarized and discussed. PMID:26820190

  7. Anion transport with halogen bonds.

    PubMed

    Jentzsch, Andreas Vargas; Matile, Stefan

    2015-01-01

    This review covers the application of halogen bonds to transport anions across lipid bilayer membranes. The introduction provides a brief description of biological and synthetic transport systems. Emphasis is on examples that explore interactions beyond the coordination with lone pairs or hydrogen bonds for the recognition of cations and anions, particularly cation-π and anion-π interactions, and on structural motifs that are relevant for transport studies with halogen bonds. Section 2 summarizes the use of macrocyclic scaffolds to achieve transport with halogen bonds, focusing on cyclic arrays of halogen-bond donors of different strengths on top of calixarene scaffolds. This section also introduces methods to study anion binding in solution and anion transport in fluorogenic vesicles. In Sect. 3, transport studies with monomeric halogen bond-donors are summarized. This includes the smallest possible organic anion transporter, trifluoroiodomethane, a gas that can be bubbled through a suspension of vesicles to turn on transport. Anion transport with a gas nicely illustrates the power of halogen bonds for anion transport. Like hydrogen bonds, they are directional and strong, but compared to hydrogen-bond donors, halogen-bond donors are more lipophilic. Section 3 also offers a concise introduction to the measurement of ion selectivity in fluorogenic vesicles and conductance experiments in planar bilayer membranes. Section 4 introduces the formal unrolling of cyclic scaffolds into linear scaffolds that can span lipid bilayers. As privileged transmembrane scaffolds, the importance of hydrophobically matching fluorescent p-oligophenyl rods is fully confirmed. The first formal synthetic ion channel that operates by cooperative multiion hopping along transmembrane halogen-bonding cascades is described. Compared to homologs for anion-π interactions, transport with halogen bonds is clearly more powerful.

  8. Photoinduced hydrogen-bonding dynamics.

    PubMed

    Chu, Tian-Shu; Xu, Jinmei

    2016-09-01

    Hydrogen bonding dynamics has received extensive research attention in recent years due to the significant advances in femtolaser spectroscopy experiments and quantum chemistry calculations. Usually, photoexcitation would cause changes in the hydrogen bonding formed through the interaction between hydrogen donor and acceptor molecules on their ground electronic states, and such transient strengthening or weakening of hydrogen bonding could be crucial for the photophysical transformations and the subsequent photochemical reactions that occurred on a time scale from tens of femtosecond to a few nanoseconds. In this article, we review the combined experimental and theoretical studies focusing on the ultrafast electronic and vibrational hydrogen bonding dynamics. Through these studies, new mechanisms and proposals and common rules have been put forward to advance our understanding of the hydrogen bondings dynamics in a variety of important photoinduced phenomena like photosynthesis, dual fluorescence emission, rotational reorientation, excited-state proton transfer and charge transfer processes, chemosensor fluorescence sensing, rearrangements of the hydrogen-bond network including forming and breaking hydrogen bond in water. Graphical Abstract We review the recent advances on exploring the photoinduced hydrogen bonding dynamics in solutions through a joint approach of laser spectroscopy and theoretical calculation. The reviewed studies have put forward a new mechanism, new proposal, and new rule for a variety of photoinduced phenomena such as photosynthesis, dual fluorescence emission, rotational reorientation, excited-state proton transfer and charge transfer, chemosensor fluorescence sensing, and rearrangements of the hydrogen-bond network in water. PMID:27491849

  9. Bond failure patterns in vivo.

    PubMed

    Linklater, Rognvald A; Gordon, Peter H

    2003-05-01

    The aim of this study was to identify the presence and pattern of differences in bond failure between tooth types in vivo when bonding orthodontic brackets with the no-mix orthodontic composite adhesive Right-On. In vivo bond failure for a single operator was recorded for 108 consecutive patients undergoing fixed-appliance orthodontic treatment. The bond failure data were analyzed by survival analysis. Time to first failure or censorship was recorded for each bonded attachment. Overall failure in the sample matched previous clinical studies but conflicted with previous ex vivo bond strength data. Mandibular and posterior teeth had significantly higher rates of failure than did maxillary and anterior teeth. The type of attachment used had a significant effect on bond survival. The results of this study confirm that in vivo bond survival is not uniform for all teeth. Comparisons between the findings of this study and those of a previous ex vivo study by the same authors failed to validate ex vivo bond strength testing as clinically relevant.

  10. Coincidence summing corrections for volume samples using the PENELOPE/penEasy Monte Carlo code.

    PubMed

    Vargas, A; Camp, A; Serrano, I; Duch, M A

    2014-05-01

    The coincidence summing correction factors estimated with penEasy, a steering program for the Monte Carlo simulation code PENELOPE, and with penEasy-eXtended, an in-house modified version of penEasy, are presented and discussed for (152)Eu and (134)Cs in volume sources. The geometries and experimental data were obtained from an intercomparison study organized by the International Committee for Radionuclide Metrology (ICRM). A significant improvement in the results calculated with PENELOPE/penEasy was obtained when X-rays are included in the (152)Eu simulations. PMID:24326316

  11. 30 CFR 281.33 - Bonds and bonding requirements.

    Code of Federal Regulations, 2010 CFR

    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 §...

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

    Code of Federal Regulations, 2010 CFR

    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...

  13. Pauling bond strength, bond length and electron density distribution

    SciTech Connect

    Gibbs, Gerald V.; Ross, Nancy L.; Cox, David F.; Rosso, Kevin M.; Iversen, Bo B.; Spackman, M. A.

    2014-01-18

    A power law regression equation, = 1.46(<ρ(rc)>/r)-0.19, connecting the average experimental bond lengths, , with the average accumulation of the electron density at the bond critical point, <ρ(rc)>, between bonded metal M and oxygen atoms, determined at ambient conditions for oxide crystals, where r is the row number of the M atom, is similar to the regression equation R(M-O) = 1.39(ρ(rc)/r)-0.21 determined for three perovskite crystals for pressures as high as 80 GPa. The two equations are also comparable with those, = 1.43(/r)-0.21, determined for a large number of oxide crystals at ambient conditions and = 1.39(/r)-0.22, determined for geometry optimized hydroxyacid molecules, that connect the bond lengths to the average Pauling electrostatic bond strength, , for the M-O bonded interactions. On the basis of the correspondence between the two sets of equations connecting ρ(rc) and the Pauling bond strength s with bond length, it appears that Pauling’s simple definition of bond strength closely mimics the accumulation of the electron density between bonded pairs of atoms. The similarity of the expressions for the crystals and molecules is compelling evidence that the M-O bonded interactions for the crystals and molecules 2 containing the same bonded interactions are comparable. Similar expressions, connecting bond lengths and bond strength, have also been found to hold for fluoride, nitride and sulfide molecules and crystals. The Brown-Shannon bond valence, σ, power law expression σ = [R1/(R(M-O)]N that has found wide use in crystal chemistry, is shown to be connected to a more universal expression determined for oxides and the perovskites, <ρ(rc)> = r[(1.41)/]4.76, demonstrating that the bond valence for a bonded interaction is likewise closely connected to the accumulation of the electron density between the bonded atoms. Unlike the Brown-Shannon expression, it is universal in that it holds for the M

  14. Microwave bonding of MEMS component

    NASA Technical Reports Server (NTRS)

    Barmatz, Martin B. (Inventor); Mai, John D. (Inventor); Jackson, Henry W. (Inventor); Budraa, Nasser K. (Inventor); Pike, William T. (Inventor)

    2005-01-01

    Bonding of MEMs materials is carried out using microwave. High microwave absorbing films are placed within a microwave cavity, and excited to cause selective heating in the skin of the material. This causes heating in one place more than another. Thereby minimizing the effects of the bonding microwave energy.

  15. Coulombic Models in Chemical Bonding.

    ERIC Educational Resources Information Center

    Sacks, Lawrence J.

    1986-01-01

    Describes a bonding theory which provides a framework for the description of a wide range of substances and provides quantitative information of remarkable accuracy with far less computational effort than that required of other approaches. Includes applications, such as calculation of bond energies of two binary hydrides (methane and diborane).…

  16. Computational Chemistry of Adhesive Bonds

    NASA Technical Reports Server (NTRS)

    Phillips, Donald H.

    1999-01-01

    This investigation is intended to determine the electrical mechanical, and chemical properties of adhesive bonds at the molecular level. The initial determinations will be followed by investigations of the effects of environmental effects on the chemistry and properties of the bond layer.

  17. Social bonding: regulation by neuropeptides

    PubMed Central

    Lieberwirth, Claudia; Wang, Zuoxin

    2014-01-01

    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. PMID:25009457

  18. Strained-bond semiconductors

    NASA Astrophysics Data System (ADS)

    Dow, John D.

    1994-05-01

    Theories of strained-bond semiconductors and superconductors have been developed that promise to have significant impact on future electronic devices of interest to the Air Force. These include: (1) development of a theory of high-temperature superconductivity based on the idea of strained-layer superlattices, (2) elucidation of the physics of doping in Type-2 semiconductor superlattices, which is now central to the development of high-speed field-effect transistors, (3) a theory of dimerization and reconstruction on (001) semiconductor surfaces, (4) theory of Mobius transforms as applied to physics and remote sensing, (5) new understanding of how defects affect the vibrational properties of semiconductors, (6) new methods of efficiently computing the trajectories of atoms in semiconductors by a priori molecular dynamics, (7) elucidation of the criteria affecting quantum-well luminescence from Si, (8) models of the effects of vacancies in large-gap Al(x)Ga(1-x)N alloys, (9) physics of rare-earth-doped silicon, (10) models of Co adsorption to silicon surfaces, (11) theories of how defects affect the properties of large band-gap superlattices, and (12) models of the effects of electronic structure on the properties of semiconductors.

  19. Hydrostatic intrapulpal pressure and bond strength of bonding systems.

    PubMed

    Prati, C; Pashley, D H; Montanari, G

    1991-01-01

    The purpose of this study was to evaluate the effect of intra-pulpal pressure on shear bond strength of three light-cured glass-ionomer cements (GC lining cement, Vitrabond, and Zionomer) and four dentin bonding agents [Gluma/Scotchbond, Scotchbond 2, MBL, and Clearfil Photo Bond]. Buccal dentin surfaces were prepared just below the DEJ by means of a diamond bur. Dentin treatments were made for Zionomer (Zionomer conditioner), Scotchbond 2 (Scotchprep), MBL (10-3 solution), Clearfil PB (H3PO4), GC lining cement (Polyacrylic acid), and Gluma/Scotchbond (EDTA). Resin composites were inserted into tubes, positioned on dentin, cured, tested after five min or 24 h, and compared with samples bonded and stored under an intra-pulpal pressure of 36 cm of saline. After 24 h in superficial dentin, intrapulpal pressure reduced the bond strength only in MBL, Scotchbond 2, and Zionomer. Clearfil PB bond strength was increased, while Vitrabond, GC lining cement, and Gluma/Scotchbond were unaffected by the presence of pulpal pressure. However, in deep dentin, Scotchbond 2 and Clearfil PB shear bond strengths were significantly reduced by storage in the presence of 36-cm H2O pulpal pressure. Only Vitrabond remained unaffected by pulpal pressure in deep dentin. PMID:1901813

  20. easyCBM[R] Mathematics Criterion Related Validity Evidence: Washington State Test. Technical Report #1010

    ERIC Educational Resources Information Center

    Anderson, Daniel; Alonzo, Julie; Tindal, Gerald

    2010-01-01

    easyCBM[R] is an online benchmark and progress monitoring assessment system designed for use within a response to intervention (RTI) framework. Part of the purpose of easyCBM[R] is to help educators identify students who may be at risk for failure. Often, students deemed at-risk are those who would be predicted to not pass the state test. Previous…

  1. Diagnostic Efficiency of easyCBM[R] Math: Oregon. Technical Report #1009

    ERIC Educational Resources Information Center

    Anderson, Daniel; Alonzo, Julie; Tindal, Gerald

    2010-01-01

    The easyCBM[R] assessment system is an online benchmark and progress monitoring assessment system designed for use within a response to intervention framework. Educators using easyCBM[R] are often interested in using the results to predict students' state test performance. In the following technical document, we report diagnostic efficiency…

  2. Diagnostic Efficiency of easyCBM[R] Math: Washington State. Technical Report #1008

    ERIC Educational Resources Information Center

    Anderson, Daniel; Alonzo, Julie; Tindal, Gerald

    2010-01-01

    easyCBM[R] is an online benchmark and progress monitoring assessment system designed for use within a response to intervention framework. Educators using easyCBM[R] are often interested in using the results to predict students' state test performance. In the following technical document, we report diagnostic efficiency statistics using a sample…

  3. easyCBM® Reading Criterion Related Validity Evidence: Grades 2-5. Technical Report #1310

    ERIC Educational Resources Information Center

    Lai, Cheng-Fei; Alonzo, Julie; Tindal, Gerald

    2013-01-01

    In this technical report, we present the results of a study to gather criterion-related evidence for Grade 2-5 easyCBM® reading measures. We used correlations to examine the relation between the easyCBM® measures and other published measures with known reliability and validity evidence, including the Gates-MacGinitie Reading Tests and the Dynamic…

  4. easyCBM® Reading Criterion Related Validity Evidence: Grades K-1. Technical Report #1309

    ERIC Educational Resources Information Center

    Lai, Cheng-Fei; Alonzo, Julie; Tindal, Gerald

    2013-01-01

    In this technical report, we present the results of a study to gather criterion-related evidence for Grade K-1 easyCBM® reading measures. We used correlations to examine the relation between the easyCBM® measures and other published measures with known reliability and validity evidence, including the Dynamic Indicators of Basic Early Literacy…

  5. Web-Based Student Evaluations of Professors: The Relations between Perceived Quality, Easiness and Sexiness

    ERIC Educational Resources Information Center

    Felton, James; Mitchell, John; Stinson, Michael

    2004-01-01

    College students critique their professors' teaching at RateMyProfessors.com, a web page where students anonymously rate their professors on Quality, Easiness, and Sexiness. Using the self-selected data from this public forum, we examine the relations between quality, easiness, and sexiness for 3190 professors at 25 universities. For faculty with…

  6. Life on Easy Street: The Persistent Need for Embodied Hopes and Down-to-Earth Games

    ERIC Educational Resources Information Center

    Kretchmar, R. Scott

    2006-01-01

    One of the greatest challenges we face in kinesiology is changing behavior--specifically, converting habitually sedentary individuals into active human beings. This task is not an easy one. Thus, when we adopt Easy Street strategies that focus on introducing, informing, and entertaining, we have very little hope of effecting such conversions. Easy…

  7. The Effectiveness of SpeechEasy during Situations of Daily Living

    ERIC Educational Resources Information Center

    O'Donnell, Jennifer J.; Armson, Joy; Kiefte, Michael

    2008-01-01

    A multiple single-subject design was used to examine the effects of SpeechEasy on stuttering frequency in the laboratory and in longitudinal samples of speech produced in situations of daily living (SDL). Seven adults who stutter participated, all of whom had exhibited at least 30% reduction in stuttering frequency while using SpeechEasy during…

  8. New Database Manipulation Tools in the Easy-Learning On-Line Platform

    ERIC Educational Resources Information Center

    Radescu, Radu; Davidescu, Andrei; Pupezescu, Valentin

    2011-01-01

    The present paper deals with the new ORM (object-relational mapping) tool introduced in the easy-learning platform. Propel 1.5 is the latest version of Propel, one of the ORMs fully compatible with the Symfony framework, and in comparison with the older versions and it has drastically improved the way the easy-learning platform can manipulate its…

  9. 27 CFR 25.95 - New bond.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false New bond. 25.95 Section 25... TREASURY LIQUORS BEER Bonds and Consents of Surety § 25.95 New bond. The appropriate TTB officer may at any time, at his or her discretion, require a new bond. A new bond is required immediately in the case...

  10. 27 CFR 25.95 - New bond.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false New bond. 25.95 Section 25... TREASURY LIQUORS BEER Bonds and Consents of Surety § 25.95 New bond. The appropriate TTB officer may at any time, at his or her discretion, require a new bond. A new bond is required immediately in the case...

  11. 27 CFR 24.153 - Strengthening bonds.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Strengthening bonds. In any instance where the penal sum of the bond on file becomes insufficient, the principal shall either give a strengthening bond with the same surety to attain a sufficient penal sum or give a... limiting the amount of either bond to less than its full penal sum. Strengthening bonds will show...

  12. 27 CFR 19.246 - Strengthening bonds.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Strengthening bonds. In all cases when the penal sum of any bond becomes insufficient, the principal shall either give a strengthening bond with the same surety to attain a sufficient penal sum, or give a new... amount of any bond to less than its full penal sum. Strengthening bonds shall show the current date...

  13. Method of bonding

    DOEpatents

    Saller, deceased, Henry A.; Hodge, Edwin S.; Paprocki, Stanley J.; Dayton, Russell W.

    1987-12-01

    1. A method of making a fuel-containing structure for nuclear reactors, comprising providing an assembly comprising a plurality of fuel units; each fuel unit consisting of a core plate containing thermal-neutron-fissionable material, sheets of cladding metal on its bottom and top surfaces, said cladding sheets being of greater width and length than said core plates whereby recesses are formed at the ends and sides of said core plate, and end pieces and first side pieces of cladding metal of the same thickness as the core plate positioned in said recesses, the assembly further comprising a plurality of second side pieces of cladding metal engaging the cladding sheets so as to space the fuel units from one another, and a plurality of filler plates of an acid-dissolvable nonresilient material whose melting point is above 2000.degree. F., each filler plate being arranged between a pair of said second side pieces and the cladding plates of two adjacent fuel units, the filler plates having the same thickness as the second side pieces; the method further comprising enclosing the entire assembly in an envelope; evacuating the interior of the entire assembly through said envelope; applying inert gas under a pressure of about 10,000 psi to the outside of said envelope while at the same time heating the assembly to a temperature above the flow point of the cladding metal but below the melting point of any material of the assembly, whereby the envelope is pressed against the assembly and integral bonds are formed between plates, sheets, first side pieces, and end pieces and between the sheets and the second side pieces; slowly cooling the assembly to room temperature; removing the envelope; and dissolving the filler plates without attacking the cladding metal.

  14. Hydroperoxides as Hydrogen Bond Donors

    NASA Astrophysics Data System (ADS)

    Møller, Kristian H.; Tram, Camilla M.; Hansen, Anne S.; Kjaergaard, Henrik G.

    2016-06-01

    Hydroperoxides are formed in the atmosphere following autooxidation of a wide variety of volatile organics emitted from both natural and anthropogenic sources. This raises the question of whether they can form hydrogen bonds that facilitate aerosol formation and growth. Using a combination of Fourier transform infrared spectroscopy, FT-IR, and ab initio calculations, we have compared the gas phase hydrogen bonding ability of tert-butylhydroperoxide (tBuOOH) to that of tert-butanol (tBuOH) for a series of bimolecular complexes with different acceptors. The hydrogen bond acceptor atoms studied are nitrogen, oxygen, phosphorus and sulphur. Both in terms of calculated redshifts and binding energies (BE), our results suggest that hydroperoxides are better hydrogen bond donors than the corresponding alcohols. In terms of hydrogen bond acceptor ability, we find that nitrogen is a significantly better acceptor than the other three atoms, which are of similar strength. We observe a similar trend in hydrogen bond acceptor ability with other hydrogen bond donors including methanol and dimethylamine.

  15. Tensile Bond Strength of Latex-Modified Bonded Concrete Overlays

    NASA Astrophysics Data System (ADS)

    Dubois, Cameron; Ramseyer, Chris

    2010-10-01

    The tensile bond strength of bonded concrete overlays was tested using the in-situ pull-off method described in ASTM C 1583 with the goal of determining whether adding latex to the mix design increases bond strength. One slab of ductile concrete (f'c > 12,000 psi) was cast with one half tined, i.e. roughened, and one half steel-troweled, i.e. smooth. The slab surface was sectioned off and overlay mixtures containing different latex contents cast in each section. Partial cores were drilled perpendicular to the surface through the overlay into the substrate. A tensile loading device applied a direct tensile load to each specimen and the load was increased until failure occurred. The tensile bond strength was then calculated for comparison between the specimens.

  16. Hydrogen bonded arrays: the power of multiple hydrogen bonds.

    PubMed

    Shokri, Alireza; Schmidt, Jacob; Wang, Xue-Bin; Kass, Steven R

    2012-02-01

    Hydrogen bond interactions in small covalent model compounds (i.e., deprotonated polyhydroxy alcohols) were measured by negative ion photoelectron spectroscopy. The experimentally determined vertical and adiabatic electron detachment energies for (HOCH(2)CH(2))(2)CHO(-)(2a), (HOCH(2)CH(2))(3)CO(-) (3a), and (HOCH(2)CH(2)CH(OH)CH(2))(3)CO(-) (4a)reveal that hydrogen-bonded networks can provide enormous stabilizations and that a single charge center not only can be stabilized by up to three hydrogen bonds but also can increase the interaction energy between noncharged OH groups by 5.8 kcal mol(-1) or more per hydrogen bond. This can lead to pK(a) values that are very different from those in water and can provide some of the impetus for catalytic processes.

  17. Copper-catalyzed cyanation of aryl iodides with α-cyanoacetates via C-CN bond activation.

    PubMed

    Zhang, Song-Lin; Huang, Lu

    2015-10-21

    A Cu(I)-catalyzed cyanation reaction of aryl iodides with α-cyanoacetates is reported herein, which uses α-cyanoacetates as the nontoxic and easy-handling CN source through copper-mediated C-CN bond cleavage. This reaction enables access to aryl nitriles with an array of functional groups on the aromatic ring in good to excellent yields.

  18. Method for vacuum fusion bonding

    DOEpatents

    Ackler, Harold D.; Swierkowski, Stefan P.; Tarte, Lisa A.; Hicks, Randall K.

    2001-01-01

    An improved vacuum fusion bonding structure and process for aligned bonding of large area glass plates, patterned with microchannels and access holes and slots, for elevated glass fusion temperatures. Vacuum pumpout of all components is through the bottom platform which yields an untouched, defect free top surface which greatly improves optical access through this smooth surface. Also, a completely non-adherent interlayer, such as graphite, with alignment and location features is located between the main steel platform and the glass plate pair, which makes large improvements in quality, yield, and ease of use, and enables aligned bonding of very large glass structures.

  19. Fusion bonding and alignment fixture

    DOEpatents

    Ackler, Harold D.; Swierkowski, Stefan P.; Tarte, Lisa A.; Hicks, Randall K.

    2000-01-01

    An improved vacuum fusion bonding structure and process for aligned bonding of large area glass plates, patterned with microchannels and access holes and slots, for elevated glass fusion temperatures. Vacuum pumpout of all the components is through the bottom platform which yields an untouched, defect free top surface which greatly improves optical access through this smooth surface. Also, a completely non-adherent interlayer, such as graphite, with alignment and location features is located between the main steel platform and the glass plate pair, which makes large improvements in quality, yield, and ease of use, and enables aligned bonding of very large glass structures.

  20. Influence of Er:YAG and Ti:sapphire laser irradiation on the microtensile bond strength of several adhesives to dentin.

    PubMed

    Portillo, M; Lorenzo, M C; Moreno, P; García, A; Montero, J; Ceballos, L; Fuentes, M V; Albaladejo, A

    2015-02-01

    The aim of the present study was to evaluate the influence of erbium:yttrium-aluminum-garnet (Er:YAG) and Ti:sapphire laser irradiation on the microtensile bond strength (MTBS) of three different adhesive systems to dentin. Flat dentin surfaces from 27 molars were divided into three groups according to laser irradiation: control, Er:YAG (2,940 nm, 100 μs, 2.7 W, 9 Hz) and Ti:sapphire laser (795 nm, 120 fs, 1 W, 1 kHz). Each group was divided into three subgroups according to the adhesive system used: two-step total-etching adhesive (Adper Scotchbond 1 XT, from now on XT), two-step self-etching adhesive (Clearfil SE Bond, from now on CSE), and all-in-one self-etching adhesive (Optibond All-in-One, from now on OAO). After 24 h of water storage, beams of section at 1 mm(2) were longitudinally cut from the samples. Each beam underwent traction test in an Instron machine. Fifteen polished dentin specimens were used for the surface morphology analysis by scanning electron microscopy (SEM). Failure modes of representative debonded microbars were SEM-assessed. Data were analyzed by ANOVA, chi-square test, and multiple linear regression (p < 0.05). In the control group, XT obtained higher MTBS than that of laser groups that performed equally. CSE showed higher MTBS without laser than that with laser groups, where Er:YAG attained higher MTBS than ultrashort laser. When OAO was used, MTBS values were equal in the three treatments. CSE obtained the highest MTBS regardless of the surface treatment applied. The Er:YAG and ultrashort laser irradiation reduce the bonding effectiveness when a two-step total-etching adhesive or a two-step self-etching adhesive are used and do not affect their effectiveness when an all-in-one self-etching adhesive is applied.

  1. 27 CFR 19.245 - Bonds and penal sums of bonds.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Bonds and penal sums of... Bonds and penal sums of bonds. The bonds, and the penal sums thereof, required by this subpart, are as follows: Penal Sum Type of bond Basis Minimum Maximum (a) Operations bond: (1) One plant bond—...

  2. 27 CFR 25.94 - Strengthening bonds.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) Requirement. When the penal sum of the brewer's bond (calculated as provided in § 25.93) in effect is not... strengthening bond in sufficient penal sum if the surety is the same as on the bond in effect. If the surety is... bond may not in any way release a former bond or limit a bond to less than the full penal sum. (c)...

  3. Modified bonded bridge space maintainer.

    PubMed

    Liegeois, F; Limme, M

    1999-01-01

    The premature loss of primary teeth can create the need for space maintenance and restoration of function. This article presents a fixed bonded space maintainer, which allows space to be maintained with economy of dental tissues.

  4. Controlling ferromagnetic easy axis in a layered MoS2 single crystal.

    PubMed

    Han, Sang Wook; Hwang, Young Hun; Kim, Seon-Ho; Yun, Won Seok; Lee, J D; Park, Min Gyu; Ryu, Sunmin; Park, Ju Sang; Yoo, Dae-Hwang; Yoon, Sang-Pil; Hong, Soon Cheol; Kim, Kwang S; Park, Young S

    2013-06-14

    We report the effective methods to induce weak ferromagnetism in pristine MoS2 persisting up to room temperature with the improved transport property, which would lead to new spintronics devices. The hydrogenation of MoS2 by heating at 300 °C for 1 h leads to the easy axis out of plane, while the irradiation of proton with a dose of 1 × 10(13) P/cm(2) leads to the easy axis in plane. The theoretical modeling supports such magnetic easy axes.

  5. Bond percolation in higher dimensions

    NASA Astrophysics Data System (ADS)

    Corwin, Eric I.; Stinchcombe, Robin; Thorpe, M. F.

    2013-07-01

    We collect results for bond percolation on various lattices from two to fourteen dimensions that, in the limit of large dimension d or number of neighbors z, smoothly approach a randomly diluted Erdős-Rényi graph. We include results on bond-diluted hypersphere packs in up to nine dimensions, which show the mean coordination, excess kurtosis, and skewness evolving smoothly with dimension towards the Erdős-Rényi limit.

  6. Method to improve commercial bonded SOI material

    DOEpatents

    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.

  7. Topology of electron charge density for chemical bonds from valence bond theory: a probe of bonding types.

    PubMed

    Zhang, Lixian; Ying, Fuming; Wu, Wei; Hiberty, Philippe C; Shaik, Sason

    2009-01-01

    To characterize the nature of bonding we derive the topological properties of the electron charge density of a variety of bonds based on ab initio valence bond methods. The electron density and its associated Laplacian are partitioned into covalent, ionic, and resonance components in the valence bond spirit. The analysis provides a density-based signature of bonding types and reveals, along with the classical covalent and ionic bonds, the existence of two-electron bonds in which most of the bonding arises from the covalent-ionic resonance energy, so-called charge-shift bonds. As expected, the covalent component of the Laplacian at the bond critical point is found to be largely negative for classical covalent bonds. In contrast, for charge-shift bonds, the covalent part of the Laplacian is small or positive, in agreement with the weakly attractive or repulsive character of the covalent interaction in these bonds. On the other hand, the resonance component of the Laplacian is always negative or nearly zero, and it increases in absolute value with the charge-shift character of the bond, in agreement with the decrease of kinetic energy associated with covalent-ionic mixing. A new interpretation of the topology of the total density at the bond critical point is proposed to characterize covalent, ionic, and charge-shift bonding from the density point of view.

  8. Breathe easy.

    PubMed

    Pearce, Lynne

    Staff at a children's hospice and the respiratory nurse team at an acute hospital are working together to help young people with Duchenne muscular dystrophy lead more active lives. The young people receive a non-invasive form of ventilation that can be used at home.

  9. Breathe Easy.

    ERIC Educational Resources Information Center

    Epstien, Barb

    1999-01-01

    Examines the different indoor air pollutants that can be found in schools and tips for controlling them. Also discussed is building analysis for monitoring biocontaminants including allergens and molds. (GR)

  10. Easy Access

    ERIC Educational Resources Information Center

    Gettelman, Alan

    2009-01-01

    School and university restrooms, locker and shower rooms have specific ADA accessibility requirements that serve the needs of staff, students and campus visitors who are disabled as a result of injury, illness or age. Taking good care of them is good for the reputation of a sensitive community institution, and fosters positive public relations.…

  11. Halogen bonds in crystal engineering: like hydrogen bonds yet different.

    PubMed

    Mukherjee, Arijit; Tothadi, Srinu; Desiraju, Gautam R

    2014-08-19

    The halogen bond is an attractive interaction in which an electrophilic halogen atom approaches a negatively polarized species. Short halogen atom contacts in crystals have been known for around 50 years. Such contacts are found in two varieties: type I, which is symmetrical, and type II, which is bent. Both are influenced by geometric and chemical considerations. Our research group has been using halogen atom interactions as design elements in crystal engineering, for nearly 30 years. These interactions include halogen···halogen interactions (X···X) and halogen···heteroatom interactions (X···B). Many X···X and almost all X···B contacts can be classified as halogen bonds. In this Account, we illustrate examples of crystal engineering where one can build up from previous knowledge with a focus that is provided by the modern definition of the halogen bond. We also comment on the similarities and differences between halogen bonds and hydrogen bonds. These interactions are similar because the protagonist atoms-halogen and hydrogen-are both electrophilic in nature. The interactions are distinctive because the size of a halogen atom is of consequence when compared with the atomic sizes of, for example, C, N, and O, unlike that of a hydrogen atom. Conclusions may be drawn pertaining to the nature of X···X interactions from the Cambridge Structural Database (CSD). There is a clear geometric and chemical distinction between type I and type II, with only type II being halogen bonds. Cl/Br isostructurality is explained based on a geometric model. In parallel, experimental studies on 3,4-dichlorophenol and its congeners shed light on the nature of halogen···halogen interactions and reveal the chemical difference between Cl and Br. Variable temperature studies also show differences between type I and type II contacts. In terms of crystal design, halogen bonds offer a unique opportunity in the strength, atom size and interaction gradation; this may be

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

    PubMed

    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.

  13. Transient liquid phase ceramic bonding

    DOEpatents

    Glaeser, Andreas M.

    1994-01-01

    Ceramics are joined to themselves or to metals using a transient liquid phase method employing three layers, one of which is a refractory metal, ceramic or alloy. The refractory layer is placed between two metal layers, each of which has a lower melting point than the refractory layer. The three layers are pressed between the two articles to be bonded to form an assembly. The assembly is heated to a bonding temperature at which the refractory layer remains solid, but the two metal layers melt to form a liquid. The refractory layer reacts with the surrounding liquid and a single solid bonding layer is eventually formed. The layers may be designed to react completely with each other and form refractory intermetallic bonding layers. Impurities incorporated into the refractory metal may react with the metal layers to form refractory compounds. Another method for joining ceramic articles employs a ceramic interlayer sandwiched between two metal layers. In alternative embodiments, the metal layers may include sublayers. A method is also provided for joining two ceramic articles using a single interlayer. An alternate bonding method provides a refractory-metal oxide interlayer placed adjacent to a strong oxide former. Aluminum or aluminum alloys are joined together using metal interlayers.

  14. Welding, Bonding and Fastening, 1984

    NASA Technical Reports Server (NTRS)

    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.

  15. Immediate bonding to bleached enamel.

    PubMed

    Nour El-din, Amal K; Miller, Barbara H; Griggs, Jason A; Wakefield, Charles

    2006-01-01

    This research sought to determine the shear bond strength, degree of resin infiltration and failure mode when organic solvent-based adhesives (acetone or ethanol) were used in immediate bonding to enamel bleached with 10% carbamide peroxide or 38% hydrogen peroxide systems. Seventy-two non-carious bovine incisors were randomly assigned to three groups of 24 specimens each-control group (deionized water), 38% hydrogen peroxide bleach group and 10% carbamide peroxide bleach group. Each group was further subdivided into two subgroups of 12 specimens each according to the adhesive system used to bond the resin composite to enamel surfaces. The two adhesive systems used were Single Bond, an ethanol-based adhesive, and One Step, an acetone-based adhesive. The shear bond strengths of 38% hydrogen peroxide and 10% carbamide peroxide were significantly lower compared to the non-bleached controls. Fractography revealed an adhesive failure mode in all specimens. Qualitative comparisons of resin tags present in the bleached and unbleached specimens using scanning electron microscopy (SEM) revealed few, thin and fragmented resin tags when 38% hydrogen peroxide and 10% carbamide peroxide were used.

  16. 21 CFR 1005.23 - Bonds.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Bonds. 1005.23 Section 1005.23 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) RADIOLOGICAL HEALTH IMPORTATION OF ELECTRONIC PRODUCTS Bonding and Compliance Procedures § 1005.23 Bonds. The bond required...

  17. 27 CFR 26.69 - Strengthening bonds.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Liquors and Articles in Puerto Rico Bonds § 26.69 Strengthening bonds. In all cases where the penal sum of... surety to attain a sufficient penal sum, or give a new bond to cover the entire liability. Strengthening... penal sum. Strengthening bonds shall show the current date of execution and the effective date....

  18. Pet Bonding and Pet Bereavement among Adolescents.

    ERIC Educational Resources Information Center

    Brown, Brenda H.; And Others

    1996-01-01

    Studied adolescent-pet bonding and bereavement following pet loss (n=55). Hypothesized that highly-bonded adolescents experience more intense grief when a pet dies than do those less bonded; degree of bonding is greater for girls than for boys; and intensity of bereavement is greater for girls than for boys. Results supported the hypotheses. (RB)

  19. 27 CFR 25.96 - Superseding bond.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Superseding bond. 25.96 Section 25.96 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT... principal submits a new bond to supersede a bond or bonds in effect, the appropriate TTB officer,...

  20. How to maximize return on bond proceeds.

    PubMed

    Deluccia, D J

    1989-09-01

    Healthcare organizations issuing tax-exempt bonds to finance the acquisition, construction, or renovation of their facilities often neglect to invest bond proceeds to gain the maximum allowable return. Bond indentures--documents that contain all the terms and provisions of the financing plan--generally spell out a number of options for investing bond proceeds.

  1. 27 CFR 24.146 - Bonds.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... (c) Wine vinegar plant bond. The proprietor of a wine vinegar plant who withdraws wine from a bonded wine premises without payment of tax for use in the manufacture of vinegar shall file a bond on TTB F 5510.2, Bond Covering Removal to and Use of Wine at Vinegar Plant, to ensure the payment of the tax...

  2. 27 CFR 24.146 - Bonds.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    .... (c) Wine vinegar plant bond. The proprietor of a wine vinegar plant who withdraws wine from a bonded wine premises without payment of tax for use in the manufacture of vinegar shall file a bond on TTB F 5510.2, Bond Covering Removal to and Use of Wine at Vinegar Plant, to ensure the payment of the tax...

  3. 27 CFR 24.146 - Bonds.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    .... (c) Wine vinegar plant bond. The proprietor of a wine vinegar plant who withdraws wine from a bonded wine premises without payment of tax for use in the manufacture of vinegar shall file a bond on TTB F 5510.2, Bond Covering Removal to and Use of Wine at Vinegar Plant, to ensure the payment of the tax...

  4. 27 CFR 24.146 - Bonds.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... (c) Wine vinegar plant bond. The proprietor of a wine vinegar plant who withdraws wine from a bonded wine premises without payment of tax for use in the manufacture of vinegar shall file a bond on TTB F 5510.2, Bond Covering Removal to and Use of Wine at Vinegar Plant, to ensure the payment of the tax...

  5. 27 CFR 24.146 - Bonds.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    .... (c) Wine vinegar plant bond. The proprietor of a wine vinegar plant who withdraws wine from a bonded wine premises without payment of tax for use in the manufacture of vinegar shall file a bond on TTB F 5510.2, Bond Covering Removal to and Use of Wine at Vinegar Plant, to ensure the payment of the tax...

  6. School Bond Success: An Exploratory Case Study

    ERIC Educational Resources Information Center

    Holt, Carleton R.; Wendt, Matthew A,; Smith, Roland M.

    2006-01-01

    Following two-failed school bond issues in 1995 and 1998, one mid-sized rural school district organized an effort that led to two successful school bond elections in 2001 and 2003. The school district's strategic plan mirrored many of the recommendations for successful bond referendums published in School Bond Success: A Strategy for Building…

  7. 21 CFR 1005.23 - Bonds.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Bonds. 1005.23 Section 1005.23 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) RADIOLOGICAL HEALTH IMPORTATION OF ELECTRONIC PRODUCTS Bonding and Compliance Procedures § 1005.23 Bonds. The bond required...

  8. 21 CFR 1005.23 - Bonds.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Bonds. 1005.23 Section 1005.23 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) RADIOLOGICAL HEALTH IMPORTATION OF ELECTRONIC PRODUCTS Bonding and Compliance Procedures § 1005.23 Bonds. The bond required...

  9. 21 CFR 1005.23 - Bonds.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Bonds. 1005.23 Section 1005.23 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) RADIOLOGICAL HEALTH IMPORTATION OF ELECTRONIC PRODUCTS Bonding and Compliance Procedures § 1005.23 Bonds. The bond required...

  10. 21 CFR 1005.23 - Bonds.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Bonds. 1005.23 Section 1005.23 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) RADIOLOGICAL HEALTH IMPORTATION OF ELECTRONIC PRODUCTS Bonding and Compliance Procedures § 1005.23 Bonds. The bond required under section 360(b) of the Act shall...

  11. 46 CFR Sec. 4 - Posting of bond.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Posting of bond. Sec. 4 Section 4 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION A-NATIONAL SHIPPING AUTHORITY BONDING OF SHIP'S PERSONNEL Sec. 4 Posting of bond. The General Agent shall retain an executed copy of each such bond in its principal...

  12. 46 CFR Sec. 2 - Amount of bond.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 8 2014-10-01 2014-10-01 false Amount of bond. Sec. 2 Section 2 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION A-NATIONAL SHIPPING AUTHORITY BONDING OF SHIP'S PERSONNEL Sec. 2 Amount of bond. The amount of the bond must be governed by the amount of monies advanced or value of...

  13. 46 CFR Sec. 2 - Amount of bond.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 8 2013-10-01 2013-10-01 false Amount of bond. Sec. 2 Section 2 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION A-NATIONAL SHIPPING AUTHORITY BONDING OF SHIP'S PERSONNEL Sec. 2 Amount of bond. The amount of the bond must be governed by the amount of monies advanced or value of...

  14. 46 CFR Sec. 4 - Posting of bond.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 8 2012-10-01 2012-10-01 false Posting of bond. Sec. 4 Section 4 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION A-NATIONAL SHIPPING AUTHORITY BONDING OF SHIP'S PERSONNEL Sec. 4 Posting of bond. The General Agent shall retain an executed copy of each such bond in its principal...

  15. 46 CFR Sec. 4 - Posting of bond.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 8 2014-10-01 2014-10-01 false Posting of bond. Sec. 4 Section 4 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION A-NATIONAL SHIPPING AUTHORITY BONDING OF SHIP'S PERSONNEL Sec. 4 Posting of bond. The General Agent shall retain an executed copy of each such bond in its principal...

  16. 46 CFR Sec. 4 - Posting of bond.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 8 2011-10-01 2011-10-01 false Posting of bond. Sec. 4 Section 4 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION A-NATIONAL SHIPPING AUTHORITY BONDING OF SHIP'S PERSONNEL Sec. 4 Posting of bond. The General Agent shall retain an executed copy of each such bond in its principal...

  17. 46 CFR Sec. 4 - Posting of bond.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 8 2013-10-01 2013-10-01 false Posting of bond. Sec. 4 Section 4 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION A-NATIONAL SHIPPING AUTHORITY BONDING OF SHIP'S PERSONNEL Sec. 4 Posting of bond. The General Agent shall retain an executed copy of each such bond in its principal...

  18. 46 CFR Sec. 2 - Amount of bond.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 8 2011-10-01 2011-10-01 false Amount of bond. Sec. 2 Section 2 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION A-NATIONAL SHIPPING AUTHORITY BONDING OF SHIP'S PERSONNEL Sec. 2 Amount of bond. The amount of the bond must be governed by the amount of monies advanced or value of...

  19. 46 CFR Sec. 2 - Amount of bond.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 8 2012-10-01 2012-10-01 false Amount of bond. Sec. 2 Section 2 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION A-NATIONAL SHIPPING AUTHORITY BONDING OF SHIP'S PERSONNEL Sec. 2 Amount of bond. The amount of the bond must be governed by the amount of monies advanced or value of...

  20. 46 CFR Sec. 2 - Amount of bond.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Amount of bond. Sec. 2 Section 2 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION A-NATIONAL SHIPPING AUTHORITY BONDING OF SHIP'S PERSONNEL Sec. 2 Amount of bond. The amount of the bond must be governed by the amount of monies advanced or value of...

  1. Three methods to measure RH bond energies

    SciTech Connect

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

    1993-03-21

    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.

  2. Halogen Bonding in Organic Synthesis and Organocatalysis.

    PubMed

    Bulfield, David; Huber, Stefan M

    2016-10-01

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

  3. Two Comments on Bond Angles

    NASA Astrophysics Data System (ADS)

    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).

  4. Anion Transport with Chalcogen Bonds.

    PubMed

    Benz, Sebastian; Macchione, Mariano; Verolet, Quentin; Mareda, Jiri; Sakai, Naomi; Matile, Stefan

    2016-07-27

    In this report, we introduce synthetic anion transporters that operate with chalcogen bonds. Electron-deficient dithieno[3,2-b;2',3'-d]thiophenes (DTTs) are identified as ideal to bind anions in the focal point of the σ holes on the cofacial endocyclic sulfur atoms. Anion binding in solution and anion transport across lipid bilayers are found to increase with the depth of the σ holes of the DTT anionophores. These results introduce DTTs and related architectures as a privileged motif to engineer chalcogen bonds into functional systems, complementary in scope to classics such as 2,2'-bipyrroles or 2,2'-bipyridines that operate with hydrogen bonds and lone pairs, respectively. PMID:27433964

  5. To Bond or Not to Bond? That Is the Question

    ERIC Educational Resources Information Center

    Balzer, Wayne E.

    2015-01-01

    This case, inspired by a real school district scenario, was developed for use in a graduate-level course in school finance. James Spencer had just been selected as the new superintendent of a low-income, 400-student, rural school district in need of many capital improvements. The previous superintendent had refused to hold a bond election because…

  6. Anodic bonding using a hybrid electrode with a two-step bonding process

    NASA Astrophysics Data System (ADS)

    Wei, Luo; Jing, Xie; Yang, Zhang; Chaobo, Li; Yang, Xia

    2012-06-01

    A two-step bonding process using a novel hybrid electrode is presented. The effects of different electrodes on bonding time, bond strength and the bonded interface are analyzed. The anodic bonding is studied using a domestic bonding system, which carries out a detailed analysis of the integrity of the bonded interface and the bond strength measurement. With the aid of the hybrid electrode, a bubble-free anodic bonding process could be accomplished within 15-20 min, with a shear strength in excess of 10 MPa. These results show that the proposed method has a high degree of application value, including in most wafer-level MEMS packaging.

  7. Fluxless flip chip bonding processes and aerial fluxless bonding technology

    NASA Astrophysics Data System (ADS)

    Kim, Dongwook

    New fluxless flip chip processes of Sn-rich non-eutectic Au-Sn solder bumps were developed using vacuum deposition and electroplating technique. It is believed that this is the first report that non-eutectic Au-Sn flip chip solder bonding is achieved without the use of flux. In order to make 200mum diameter and 10mum thick Au-Sn solder bump 0.03mum of Cr, 10mum of Sn and 0.3mum of Au were vacuum deposited on the Si wafer through the high carbon steal stencil mask. Nearly void-free solder bumps with small grains of AuSn4 intermetallic compound were achieved. The re-melting temperature of solder bumps was measured to be 220°C. In the second part, first, the fluxless bonding process was performed in hydrogen environment with electroplated 4 mm x 4mm Au-Sn multi-layer chips if electroplating technique is compatible with our process. High quality and nearly void free solder joint was successfully achieved with this new process. After proving compatibility of the process, tall electroplated Sn/Au bumps (50 mum) were produced by photolithography method using Su-8 photoresist. The bumps in the chip were flip chip bonded to the borosilicate glass wafer coated with Cr (0.03 mum) and Au (0.05 mum) pads without using any flux. Fluxless and lead-free bonding technology in air ambient based on non eutectic 5 at. % Au-95 at. % Sn and eutectic 57 at. %Sn-43 at. % Bi with Au capping layer have been developed and studied. To understand the fluxless bonding principles in air ambient, phase formation mechanism of Au-Sn intermetallics embedded in Bi matrix has been postulated. The Au-Sn intermetallic-capping layer covers most outer surface of the samples and inhibits formation of oxide layer due to the minimizing exposure of (beta-Sn) phase to the air. In conclusion, new-lead free and fluxless bonding processes for flip chip packages were developed. In this work, Sn-rich Au-Sn flip chip solder bumps using vacuum deposition and electroplating process were successfully produced. It is

  8. 76 FR 21849 - Defense Federal Acquisition Regulation Supplement; Ships Bunkers Easy Acquisition (SEA) Card® and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-19

    ... Regulation Supplement; Ships Bunkers Easy Acquisition (SEA) Card and Aircraft Ground Services (DFARS Case... include purchases of marine fuel, oil, and refueling-related items using the Ships Bunkers Easy... the purchase of marine fuel using the Ships' bunkers Easy Acquisition (SEA) Card in lieu of the...

  9. 46 CFR Sec. 10 - Bonds.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... November 1950) respectively, shall be used. Such bonds (in the respective penal sums of 50 percent of the... penal sum of 40 percent of such job order contract price) shall guarantee the Contractor's performance... contractors to the awarding offices (General Agents or local offices of NSA) to verify the correctness of...

  10. Mother-To-Infant 'Bonding'.

    ERIC Educational Resources Information Center

    Herbert, M.; And Others

    1982-01-01

    Critically reviews the concept of "bonding," exploring its empirical basis and the implications that follow from its application in practice. Among the conclusions reached are that there is a tendency to oversimplify attachment phenomena and that the notion of a sensitive period for attachment has no direct empirical support. (RH)

  11. Electronegativity and the Bond Triangle

    ERIC Educational Resources Information Center

    Meek, Terry L.; Garner, Leah D.

    2005-01-01

    The usefulness of the bond triangle for categorizing compounds of the main-group elements may be extended by the use of weighted average electronegativities to allow distinction between compounds of the same elements with different stoichiometries. In such cases a higher valency for the central atom leads to greater covalent character and the…

  12. Bonding Elastomers To Metal Substrates

    NASA Technical Reports Server (NTRS)

    Dickerson, George E.; Kelley, Henry L.

    1990-01-01

    Improved, economical method for bonding elastomers to metals prevents failures caused by debonding. In new technique, vulcanization and curing occur simultaneously in specially designed mold that acts as form for desired shape of elastomer and as container that positions and supports metal parts. Increases interface adhesion between metal, adhesive, and elastomer.

  13. Enhanced rigid-bond restraints

    SciTech Connect

    Thorn, Andrea; Dittrich, Birger; Sheldrick, George M.

    2012-07-01

    An extension is proposed to the rigid-bond description of atomic thermal motion in crystals. The rigid-bond model [Hirshfeld (1976 ▶). Acta Cryst. A32, 239–244] states that the mean-square displacements of two atoms are equal in the direction of the bond joining them. This criterion is widely used for verification (as intended by Hirshfeld) and also as a restraint in structure refinement as suggested by Rollett [Crystallographic Computing (1970 ▶), edited by F. R. Ahmed et al., pp. 167–181. Copenhagen: Munksgaard]. By reformulating this condition, so that the relative motion of the two atoms is required to be perpendicular to the bond, the number of restraints that can be applied per anisotropic atom is increased from about one to about three. Application of this condition to 1,3-distances in addition to the 1,2-distances means that on average just over six restraints can be applied to the six anisotropic displacement parameters of each atom. This concept is tested against very high resolution data of a small peptide and employed as a restraint for protein refinement at more modest resolution (e.g. 1.7 Å)

  14. Bonded polyimide fuel cell package

    DOEpatents

    Morse, Jeffrey D.; Jankowski, Alan; Graff, Robert T.; Bettencourt, Kerry

    2010-06-08

    Described herein are processes for fabricating microfluidic fuel cell systems with embedded components in which micron-scale features are formed by bonding layers of DuPont Kapton.TM. polyimide laminate. A microfluidic fuel cell system fabricated using this process is also described.

  15. Non-bonded ultrasonic transducer

    DOEpatents

    Eoff, J.M.

    1984-07-06

    A mechanically assembled non-bonded ultrasonic transducer includes a substrate, a piezoelectric film, a wetting agent, a thin metal electrode, and a lens held in intimate contact by a mechanical clamp. No epoxy or glue is used in the assembly of this device.

  16. Naive empiricism and dogmatism in confidence research: a critical examination of the hard-easy effect.

    PubMed

    Juslin, P; Winman, A; Olsson, H

    2000-04-01

    Two robust phenomena in research on confidence in one's general knowledge are the overconfidence phenomenon and the hard-easy effect. In this article, the authors propose that the hard-easy effect has been interpreted with insufficient attention to the scale-end effects, the linear dependency, and the regression effects in data and that the continued adherence to the idea of a "cognitive overconfidence bias" is mediated by selective attention to particular data sets. A quantitative review of studies with 2-alternative general knowledge items demonstrates that, contrary to widespread belief, there is (a) very little support for a cognitive-processing bias in these data; (b) a difference between representative and selected item samples that is not reducible to the difference in difficulty; and (c) near elimination of the hard-easy effect when there is control for scale-end effects and linear dependency. PMID:10789203

  17. EasyKSORD: A Platform of Keyword Search Over Relational Databases

    NASA Astrophysics Data System (ADS)

    Peng, Zhaohui; Li, Jing; Wang, Shan

    Keyword Search Over Relational Databases (KSORD) enables casual users to use keyword queries (a set of keywords) to search relational databases just like searching the Web, without any knowledge of the database schema or any need of writing SQL queries. Based on our previous work, we design and implement a novel KSORD platform named EasyKSORD for users and system administrators to use and manage different KSORD systems in a novel and simple manner. EasyKSORD supports advanced queries, efficient data-graph-based search engines, multiform result presentations, and system logging and analysis. Through EasyKSORD, users can search relational databases easily and read search results conveniently, and system administrators can easily monitor and analyze the operations of KSORD and manage KSORD systems much better.

  18. Systematic review of EASY-care needs assessment for community-dwelling older people

    PubMed Central

    Craig, Christopher; Chadborn, Neil; Sands, Gina; Tuomainen, Helena; Gladman, John

    2015-01-01

    Background: undertaking comprehensive geriatric assessments (CGAs) combined with long-term health and social care management can improve the quality of life of older people [ 1]. The EASY-Care tool is a CGA instrument designed for assessing the physical, mental and social functioning and unmet health and social needs of older people in community settings or primary care. It has also been used as a frailty assessment tool and for gathering population-level data. Objective: to review the evidence of reliability, validity and acceptability of EASY-Care and its appropriateness for assessing the needs of community-dwelling older people. Methods: systematic search of literature databases using pre-defined search terms (January 1994—May 2014) for English language articles reporting on the reliability, validity, acceptability and implementation of EASY-Care in primary care and community settings. Eligible articles were critically reviewed. Discussion papers mapping professionals' use of the tool were also included as these could be considered an aspect of validity. Results: twenty-nine papers met the inclusion criteria and underwent data extraction. A narrative synthesis was performed, because there was a variety of quantitative and qualitative outcomes and characteristics. Reliability evidence for EASY-Care is minimal. Evidence for validity is good, and it has received numerous positive endorsements of acceptability in international settings from older people and practitioners. Conclusion: evidence supports the use of EASY-Care for individual needs assessment; further research is needed for other uses. Of the papers that made statements about who should administer EASY-Care, the majority indicated that nurses were preferable to self-completion. PMID:25911539

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

    PubMed Central

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

    2014-01-01

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

  20. The Environment for Application Software Integration and Execution (EASIE) version 1.0. Volume 1: Executive overview

    NASA Technical Reports Server (NTRS)

    Rowell, Lawrence F.; Davis, John S.

    1989-01-01

    The Environment for Application Software Integration and Execution (EASIE) provides a methodology and a set of software utility programs to ease the task of coordinating engineering design and analysis codes. EASIE was designed to meet the needs of conceptual design engineers that face the task of integrating many stand-alone engineering analysis programs. Using EASIE, programs are integrated through a relational database management system. Volume 1, Executive Overview, gives an overview of the functions provided by EASIE and describes their use. Three operational design systems based upon the EASIE software are briefly described.

  1. Model for the easy-axis alignment of chemically synthesized L10 FePt nanoparticles

    NASA Astrophysics Data System (ADS)

    Harrell, J. W.; Kang, S.; Jia, Z.; Nikles, D. E.; Chantrell, R.; Satoh, A.

    2005-11-01

    Analytical and computational models of the easy-axis orientation process in magnetic nanoparticle systems are investigated and compared with experimental data. The computational model gives good agreement with experiment on the assumption of a reduced anisotropy constant, which is ascribed to the existence of aggregation. It is found that the degree of orientation depends on the parameter KV /kT, with K the anisotropy constant and V the nanoparticle volume, which governs the coupling of the easy axis to the magnetic moment. A simple and useful analytical expression is derived, from which the primary conditions for good alignment are determined.

  2. Uniaxial ferromagnetic film in magnetic field perpendicular to the easy axis

    NASA Astrophysics Data System (ADS)

    Korneta, W.; Pytel, Z.

    1987-08-01

    The spin model of single domain ferromagnetic film is considered. Only the nearest-neighbor interactions are taken into account. The interactions depend on distances from surfaces. The external magnetic field is applied perpendicular to the easy axis lying in the plane of the film. The thermodynamic behaviour of the model is studied near the second-order ferro-paramagnetic phase transition for the component of the magnetization in the direction of the easy axis. The molecular-field theory is used. The phase diagram and profiles of the order parameter are obtained. Different feasible investigations of the phase transition are compared.

  3. Bubble and skyrmion crystals in frustrated magnets with easy-axis anisotropy

    DOE PAGES

    Hayami, Satoru; Lin, Shi-Zeng; Batista, Cristian D.

    2016-05-12

    We clarify the conditions for the emergence of multiple-Q structures out of lattice and easy-axis spin anisotropy in frustrated magnets. By considering magnets whose exchange interaction has multiple global minima in momentum space, we find that both types of anisotropy stabilize triple-Q orderings. Moderate anisotropy leads to a magnetic field-induced skyrmion crystal, which evolves into a bubble crystal for increasing spatial and spin anisotropy. Finally, the bubble crystal exhibits a quasi-continuous (devil’s staircase) temperature dependent ordering wave-vector, characteristic of the competition between frustrated exchange and strong easy-axis anisotropy.

  4. Method for fusion bonding thermoplastic composites

    SciTech Connect

    Benatar, A.; Gutowski, T.G.

    1986-10-01

    Bonding of thermoplastic composites is a critical step in the manufacture of aerospace structures. The objective of this project is to investigate different methods for fusion bonding thermoplastic composites quickly, with a good bond strength, and without warping and deconsolidation. This is best accomplished by heating and melting the thermoplastic on the bond surface only, and then pressing the parts together for a fusion bond. For this purpose, a variety of surface heating techniques were examined for bonding of PEEK and J Polymer composites. These included: resistance heating, infrared heating, induction heating, dielectric/microwave heating, and ultrasonic welding. 20 references, 10 figures, 1 table.

  5. Chemical Bonding Technology: Direct Investigation of Interfacial Bonds

    NASA Technical Reports Server (NTRS)

    Koenig, J. L.; Boerio, F. J.; Plueddemann, E. P.; Miller, J.; Willis, P. B.; Cuddihy, E. F.

    1986-01-01

    This is the third Flat-Plate Solar Array (FSA) Project document reporting on chemical bonding technology for terrestrial photovoltaic (PV) modules. The impetus for this work originated in the late 1970s when PV modules employing silicone encapsulation materials were undergoing delamination during outdoor exposure. At that time, manufacturers were not employing adhesion promoters and, hence, module interfaces in common with the silicone materials were only in physical contact and therefore easily prone to separation if, for example, water were to penetrate to the interfaces. Delamination with silicone materials virtually vanished when adhesion promoters, recommended by silicone manufacturers, were used. The activities related to the direct investigation of chemically bonded interfaces are described.

  6. Interaction geometries and energies of hydrogen bonds to C[double bond]O and C[double bond]S acceptors: a comparative study.

    PubMed

    Wood, Peter A; Pidcock, Elna; Allen, Frank H

    2008-08-01

    The occurrence, geometries and energies of hydrogen bonds from N-H and O-H donors to the S acceptors of thiourea derivatives, thioamides and thiones are compared with data for their O analogues - ureas, amides and ketones. Geometrical data derived from the Cambridge Structural Database indicate that hydrogen bonds to the C[double bond]S acceptors are much weaker than those to their C[double bond]O counterparts: van der Waals normalized hydrogen bonds to O are shorter than those to S by approximately 0.25 A. Further, the directionality of the approach of the hydrogen bond with respect to S, defined by the C[double bond]S...H angle, is in the range 102-109 degrees , much lower than the analogous C[double bond]O...H angle which lies in the range 127-140 degrees . Ab initio calculations using intermolecular perturbation theory show good agreement with the experimental results: the differences in hydrogen-bond directionality are closely reproduced, and the interaction energies of hydrogen bonds to S are consistently weaker than those to O, by approximately 12 kJ mol(-1), for each of the three compound classes. There are no CSD examples of hydrogen bonds to aliphatic thiones, (Csp(3))(2)C=S, consistent with the near-equality of the electronegativities of C and S. Thioureas and thioamides have electron-rich N substituents replacing the Csp(3) atoms. Electron delocalization involving C[double bond]S and the N lone pairs then induces a significant >C(delta+)[double bond]S(delta-) dipole, which enables the formation of the medium-strength C[double bond]S...H bonds observed in thioureas and thioamides.

  7. Complexes between hypohalous acids and phosphine derivatives. Pnicogen bond versus halogen bond versus hydrogen bond

    NASA Astrophysics Data System (ADS)

    Li, Qingzhong; Zhu, Hongjie; Zhuo, Hongying; Yang, Xin; Li, Wenzuo; Cheng, Jianbo

    2014-11-01

    The complexes of HOBr:PH2Y (Y = H, F, Cl, Br, CH3, NH2, OH, and NO2), HOCl:PH2F, and HOI:PH2F have been investigated with ab initio calculations at the MP2/aug-cc-pVTZ level. Four types of structures (1, 2, 3a, and 3b) were observed for these complexes. 1 is stabilized by an O⋯P pnicogen bond, 2 by a P⋯X halogen bond, 3a by a H⋯P hydrogen bond and a P⋯X pnicogen bond, and 3b by H⋯P and H⋯Br hydrogen bonds. Their relative stability is related to the halogen X of HOX and the substituent Y of PH2Y. These structures can compete with interaction energy of -10.22 ∼ -29.40 kJ/mol. The Hsbnd O stretch vibration shows a small red shift in 1, a small irregular shift in 2, but a prominent red shift in 3a and 3b. The Xsbnd O stretch vibration exhibits a smaller red shift in 1, a larger red shift in 2, but an insignificant blue shift in 3a and 3b. The Psbnd Y stretch vibration displays a red shift in 1 but a blue shift in 2, 3a, and 3b. The formation mechanism, stability, and properties of these structures have been analyzed with molecular electrostatic potentials, orbital interactions, and non-covalent interaction index.

  8. Shear bond strength of two resin cements to human root dentin using three dentin bonding agents.

    PubMed

    Gogos, C; Stavrianos, C; Kolokouris, I; Economides, N; Papadoyannis, I

    2007-01-01

    This study compared the bond strength of two resin cements to human root dentin when used with three bonding agents. The materials used were Rely X ARC and Perma Cem, two one-bottle bonding agents (Single Bond, Bond-1) and one self-etching bonding agent (Clearfil SE Bond). The dentin was obtained from single rooted human teeth, and the specimens were treated with either 15% EDTA or 37% phosphoric acid to remove the smear layer, except in groups where the self-etching bonding agent was used. The resin cements were placed on dentin surfaces with the use of bonding agents. Shear bond strength (SBS) was tested using a single plane shear test assembly. The dentin specimens were divided into 10 groups. Eight groups were pre-treated with EDTA or phosphoric acid to remove the smear layer, followed by a bonding agent (Bond-1 or Single Bond) and resin cement (Rely X or Perma Cem). In the two remaining groups, the smear layer was left intact, and the two resins cements were used in combination with the self-etching bonding agent (Clearfil SE Bond). No statistically significant differences were observed among the eight groups treated with one-bottle bonding agents. The mean bond strengths of the two groups treated with the self-etching bonding agent did not differ significantly from each other but were both significantly greater than the bond strengths of all the other groups. The results of this study also showed that EDTA can be used as an alternative to phosphoric acid in bonding procedures for resin cements. However, the bond strengths of resin cements, in combination with a self-etching bonding agent, were significantly greater than those of the same cements when used with one-bottle bonding agents.

  9. The Three Bears and Other Plays: Six Easy Plays Especially Written for Educationally Handicapped Children.

    ERIC Educational Resources Information Center

    Cassie, Dhyan

    This booklet contains six easy plays written for educationally handicapped children. The plays are brief, use few characters and simple language and plots, and are based on fairy tales. Titles are: (1) "The Three Bears'" (2) "The Gingerbread Boy'" (3) "Little Red Riding Hood'" (4) "The Three Billy Goats Gruff'" (5) "Hansel and Gretel'" and (6)…

  10. Technical Adequacy of the easyCBM Grade 2 Reading Measures. Technical Report #1004

    ERIC Educational Resources Information Center

    Jamgochian, Elisa; Park, Bitnara Jasmine; Nese, Joseph F. T.; Lai, Cheng-Fei; Saez, Leilani; Anderson, Daniel; Alonzo, Julie; Tindal, Gerald

    2010-01-01

    In this technical report, we provide reliability and validity evidence for the easyCBM[R] Reading measures for grade 2 (word and passage reading fluency and multiple choice reading comprehension). Evidence for reliability includes internal consistency and item invariance. Evidence for validity includes concurrent, predictive, and construct…

  11. Not So Easy Going: The Policy Environments of Small Urban Schools and Schools-within-Schools.

    ERIC Educational Resources Information Center

    Raywid, Mary Anne; Schmerler, Gil; Phillips, Stephen E.; Smith, Gregory A.

    Downsizing schools--creating small schools, schools-within-schools, and small learning communities--has been a highly favored school reform strategy of recent years, one that is supported by considerable research. Yet for many of these schools, the going has not been easy, bedeviled by bureaucratic resistance, public misunderstanding, and…

  12. The Characterization of an Easy-to-Operate Inexpensive Student-Built Fluorimeter

    ERIC Educational Resources Information Center

    Wigton, Benjamin T.; Chohan, Balwant S.; Kreuter, Rod; Sykes, Dan

    2011-01-01

    A compact, rugged, and portable fluorimeter was designed and constructed using a 460 nm light-emitting diode for the excitation and a silicon photodiode for detection. The total cost of such an instrument is less than $110, thus allowing for deployment of multiple instruments at low cost. The fluorimeter is easy to operate and has been…

  13. The Use of Cylindrical Lenses in Easy Experiments for Physics Education and the Magic Arts

    ERIC Educational Resources Information Center

    Bednarek, Stanislaw; Krysiak, Jerzy

    2011-01-01

    The purpose of this article is to present the properties of cylindrical lenses and provide some examples of their use in easy school physics experiments. Such experiments could be successfully conducted in the context of science education, in fun experiments that teach physics and in science fair projects, or used to entertain an audience by…

  14. Easy to Make Teaching Aids for Nutrition Teaching-Learning. UNESCO Nutrition Education Series, Issue 10.

    ERIC Educational Resources Information Center

    Barclay, Ellen J., Comp.; Van der Vynckt, Susan

    This issue of the UNESCO Nutrition Education Series presents a sampling of ideas for teaching aids created from experiences in developing countries and is representative of materials currently Being compiled for Volume IV of the UNESCO Resource Pack for Nutrition Teaching-Learning, "Easy to Make Teaching Aids for Nutrition Teaching-Learning." The…

  15. The Alignment of easyCBM[R] Math Measures to Curriculum Standards. Technical Report #1002

    ERIC Educational Resources Information Center

    Nese, Joseph F. T.; Lai, Cheng-Fei; Anderson, Daniel; Park, Bitnara Jasmine; Tindal, Gerald; Alonzo, Julie

    2010-01-01

    The purpose of this study was to examine the alignment of the easyCBM[R] mathematics benchmark and progress monitoring measures to the National Council of Teachers of Mathematics "Curriculum Focal Points" (NCTM, 2006). Based on Webb's alignment model (1997, 2002), we collected expert judgments on individual math items across a sampling of forms…

  16. Easy Reading: Book Series and Periodicals for Less Able Readers. Reading Aids Series, Second Edition.

    ERIC Educational Resources Information Center

    Ryder, Randall J.; And Others

    Intended for classroom teachers and reading specialists, this monograph features high-interest, easy-to-read materials for readers who experience difficulty with text. The monograph, a revised and updated edition of a 1979 publication, includes an overview and a bibliography that contains reviews of 44 book series and 15 periodicals. The entries…

  17. Easy-plane anisotropy stabilizes skyrmions in 2D chiral magnets

    NASA Astrophysics Data System (ADS)

    Rowland, James; Banerjee, Sumilan; Randeria, Mohit

    2014-03-01

    Experiments on two-dimensional (2D) chiral magnetic materials, like thin films of non-centrosymmetric helimagnets and metallic magnetic layers, have revealed interesting spatially modulated spin textures such as spirals and skyrmions. Motivated by this we study the ground-state phase diagram for a 2D chiral magnet in a magnetic field using a Ginzburg-Landau model, with Dzyaloshinskii-Moriya (DM) term, anisotropic exchange and single-ion anisotropy. The easy-axis anisotropy region of the phase diagram has been well-studied, whereas the easy-plane region has not been discussed. In the easy-plane region, we find an unexpectedly large stable skyrmion crystal (SkX) phase in a perpendicular magnetic field. We find re-entrant transitions between ferromagnetic and SkX phases, and intriguing internal structure of the skyrmion core with two-length scales. We argue that such an easy-plane anisotropy arises naturally from the compass terms induced by spin-orbit coupling that is also responsible for the DM term, as proposed recently in the context of oxide interfaces. We also discuss the phase diagram in a tilted field configuration, relevant for torque magnetometry experiments. JR and MR supported by NSF MRSEC DMR-0820414 and SB by DOE-BES DE-SC0005035.

  18. E-1 Dynamic Fluid-Flow Model Update: EASY/ROCETS Enhancement and Model Development Support

    NASA Technical Reports Server (NTRS)

    Follett, Randolph F.; Taylor, Robert P.

    1998-01-01

    This report documents the research conducted to update computer models for dynamic fluid flow simulation of the E-1 test stand subsystems at te NASA John C. Stennis Space Center.Work also involved significant upgrades to the capabilities of EASY/ROCKETS library through the inclusion of the NIST-12 thermodynamic property database and development of new control system modules.

  19. American History Time Lines. Grades 4-8. Big, Reproducible, Easy-To-Use.

    ERIC Educational Resources Information Center

    Buckley, Susan Washburn

    This resource is designed to enhance learning about topics in United States history. The reproducible time lines are easy to use and is designed to encourage students to research other dates and events of the era under study. Suggestions are given for classroom use. The introduction has instructional subjects, such as: "12 Great Ways To Use These…

  20. Digital Technology in the Visual Arts Classroom: An [un]Easy Partnership

    ERIC Educational Resources Information Center

    Wilks, Judith; Cutcher, Alexandra; Wilks, Susan

    2012-01-01

    This article scrutinizes the dichotomy of the uneasy and easy partnerships that exist between digital technology and visual arts education. The claim that by putting computers into schools "we have bought 'one half of a product'... we've bought the infrastructure and the equipment but we haven't bought the educational…

  1. Neonatal carrier: An easy to make alternative device to costly transport chambers

    PubMed Central

    Joshi, Milind; Singh, Sangram; Negi, Anupama; Vyas, Tanmay; Chourishi, Vigya; Jain, Anvesh

    2010-01-01

    The transport of sick neonates to the surgical centers or transportation within the center is an essential requirement of neonatal surgery. Neonatal transport incubators are costly, space occupying, and are not available at many places in the developing countries. We report here a cheap yet effective and easy to make, alternate neonatal carrier device. PMID:21170195

  2. Introducing Human Population Biology through an Easy Laboratory Exercise on Mitochondrial DNA

    ERIC Educational Resources Information Center

    Pardinas, Antonio F.; Dopico, Eduardo; Roca, Agustin; Garcia-Vazquez, Eva; Lopez, Belen

    2010-01-01

    This article describes an easy and cheap laboratory exercise for students to discover their own mitochondrial haplogroup. Students use buccal swabs to obtain mucosa cells as noninvasive tissue samples, extract DNA, and with a simple polymerase chain reaction-restriction fragment length polymorphism analysis they can obtain DNA fragments of…

  3. Long-Term Effectiveness of the SpeechEasy Fluency-Enhancement Device

    ERIC Educational Resources Information Center

    Gallop, Ronald F.; Runyan, Charles M.

    2012-01-01

    The SpeechEasy has been found to be an effective device for reduction of stuttering frequency for many people who stutter (PWS); published studies typically have compared stuttering reduction at initial fitting of the device to results achieved up to one year later. This study examines long-term effectiveness by examining whether effects of the…

  4. Analyzing the Reliability of the easyCBM Reading Comprehension Measures: Grade 2. Technical Report #1201

    ERIC Educational Resources Information Center

    Lai, Cheng-Fei; Irvin, P. Shawn; Alonzo, Julie; Park, Bitnara Jasmine; Tindal, Gerald

    2012-01-01

    In this technical report, we present the results of a reliability study of the second-grade multiple choice reading comprehension measures available on the easyCBM learning system conducted in the spring of 2011. Analyses include split-half reliability, alternate form reliability, person and item reliability as derived from Rasch analysis,…

  5. Analyzing the Reliability of the easyCBM Reading Comprehension Measures: Grade 6. Technical Report #1205

    ERIC Educational Resources Information Center

    Irvin, P. Shawn; Alonzo, Julie; Park, Bitnara Jasmine; Lai, Cheng-Fei; Tindal, Gerald

    2012-01-01

    In this technical report, we present the results of a reliability study of the sixth-grade multiple choice reading comprehension measures available on the easyCBM learning system conducted in the spring of 2011. Analyses include split-half reliability, alternate form reliability, person and item reliability as derived from Rasch analysis,…

  6. Analyzing the Reliability of the easyCBM Reading Comprehension Measures: Grade 7. Technical Report #1206

    ERIC Educational Resources Information Center

    Irvin, P. Shawn; Alonzo, Julie; Lai, Cheng-Fei; Park, Bitnara Jasmine; Tindal, Gerald

    2012-01-01

    In this technical report, we present the results of a reliability study of the seventh-grade multiple choice reading comprehension measures available on the easyCBM learning system conducted in the spring of 2011. Analyses include split-half reliability, alternate form reliability, person and item reliability as derived from Rasch analysis,…

  7. Analyzing the Reliability of the easyCBM Reading Comprehension Measures: Grade 4. Technical Report #1203

    ERIC Educational Resources Information Center

    Park, Bitnara Jasmine; Irvin, P. Shawn; Alonzo, Julie; Lai, Cheng-Fei; Tindal, Gerald

    2012-01-01

    In this technical report, we present the results of a reliability study of the fourth-grade multiple choice reading comprehension measures available on the easyCBM learning system conducted in the spring of 2011. Analyses include split-half reliability, alternate form reliability, person and item reliability as derived from Rasch analysis,…

  8. Analyzing the Reliability of the easyCBM Reading Comprehension Measures: Grade 5. Technical Report #1204

    ERIC Educational Resources Information Center

    Park, Bitnara Jasmine; Irvin, P. Shawn; Lai, Cheng-Fei; Alonzo, Julie; Tindal, Gerald

    2012-01-01

    In this technical report, we present the results of a reliability study of the fifth-grade multiple choice reading comprehension measures available on the easyCBM learning system conducted in the spring of 2011. Analyses include split-half reliability, alternate form reliability, person and item reliability as derived from Rasch analysis,…

  9. Analyzing the Reliability of the easyCBM Reading Comprehension Measures: Grade 3. Technical Report #1202

    ERIC Educational Resources Information Center

    Lai, Cheng-Fei; Irvin, P. Shawn; Park, Bitnara Jasmine; Alonzo, Julie; Tindal, Gerald

    2012-01-01

    In this technical report, we present the results of a reliability study of the third-grade multiple choice reading comprehension measures available on the easyCBM learning system conducted in the spring of 2011. Analyses include split-half reliability, alternate form reliability, person and item reliability as derived from Rasch analysis,…

  10. Easy Access to Firearms: Juveniles' Risks for Violent Offending and Violent Victimization

    ERIC Educational Resources Information Center

    Ruback, R. Barry; Shaffer, Jennifer N.; Clark, Valerie A.

    2011-01-01

    Keeping firearms at home may increase personal safety but it may also increase the risk of injury. This study uses data from three waves of the National Longitudinal Study of Adolescent Health to assess the extent to which adolescents' easy access to firearms at home increases the risk of violent offending and violent victimization. Access to…

  11. Formative Assessment Made Easy: Templates for Collecting Daily Data in Inclusive Classrooms

    ERIC Educational Resources Information Center

    Cornelius, Kyena E.

    2013-01-01

    Special educators are required to collect data on student progress and use it as formative data to inform instructional decisions. Being told to collect student data without being shown how to effectively and efficiently collect it, may cause teachers to become overwhelmed. This article provides three easy-to-use templates to facilitate quick data…

  12. Quick and Easy: Use Screen Capture Software to Train and Communicate

    ERIC Educational Resources Information Center

    Schuster, Ellen

    2011-01-01

    Screen capture (screen cast) software can be used to develop short videos for training purposes. Developing videos is quick and easy. This article describes how these videos are used as tools to reinforce face-to-face and interactive TV curriculum training in a nutrition education program. Advantages of developing these videos are shared.…

  13. The Effect of SpeechEasy on Stuttering Frequency in Laboratory Conditions

    ERIC Educational Resources Information Center

    Armson, Joy; Kiefte, Michael; Mason, Jessica; De Croos, Dayani

    2006-01-01

    The effect of SpeechEasy on stuttering frequency during speech produced in a laboratory setting was examined. Thirteen adults who stutter participated. Stuttering frequencies in two baseline conditions were compared to stuttering frequencies with the device fitted according to the manufacturer's protocol. The fitting protocol includes instructions…

  14. Supervisor Perspective on the Process and Outcome of Giving Easy, Difficult, or No Feedback to Supervisees

    ERIC Educational Resources Information Center

    Hoffman, Mary Ann; Hill, Clara E.; Holmes, Stacey E.; Freitas, Gary F.

    2005-01-01

    Fifteen counseling center supervisors were interviewed about 3 instances related to important feedback with an intern supervisee: in which the feedback was given easily, in which it was given reluctantly or with difficulty, and another in which it was not given. Supervisors indicated that easy feedback was most often about clinical problems, was…

  15. 78 FR 73915 - Community Alliance, Inc., Defi Global, Inc., Easy Energy, Inc., Industry Concept Holdings, Inc...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-09

    ... From the Federal Register Online via the Government Publishing Office SECURITIES AND EXCHANGE COMMISSION Community Alliance, Inc., Defi Global, Inc., Easy Energy, Inc., Industry Concept Holdings, Inc... information concerning the securities of Industry Concept Holdings, Inc. because it has not filed any...

  16. Understanding Resonance Graphs Using Easy Java Simulations (EJS) and Why We Use EJS

    ERIC Educational Resources Information Center

    Wee, Loo Kang; Lee, Tat Leong; Chew, Charles; Wong, Darren; Tan, Samuel

    2015-01-01

    This paper reports a computer model simulation created using Easy Java Simulation (EJS) for learners to visualize how the steady-state amplitude of a driven oscillating system varies with the frequency of the periodic driving force. The simulation shows (N = 100) identical spring-mass systems being subjected to (1) a periodic driving force of…

  17. Hey! Somebody Read to Me! Ten Easy Ways to Include Reading Every Day. Family Ties

    ERIC Educational Resources Information Center

    Ulmen, Marie Christine

    2005-01-01

    If a child does not learn to read in the early grades, there are few opportunities for them to catch up. Therefore, the extent of a child's exposure to reading before the early school years is not only important, but critical. In this column, the author suggests ten easy ways to make reading a part of every young child's day: (1) Read and reread…

  18. Generalization of Changes in Children's Preferences for Easy or Difficult Goals Induced through Peer Modeling.

    ERIC Educational Resources Information Center

    Sagotsky, Gerald; Lepper, Mark R.

    1982-01-01

    Explores the generalization of changes in children's preferences for easy or difficult goals, when their preferences are induced by exposure to peer models playing a novel athletic game. Subjects played the same game immediately after exposure, participated in a "spelling bee" three weeks later, and chose puzzles of differing levels of difficulty…

  19. Study of bump bonding technology

    SciTech Connect

    Selcuk Cihangir et al.

    2003-10-17

    Pixel detectors proposed for the new generation of hadron collider experiments will use bump-bonding technology based on either indium or Pb/Sn solder to connect the front-end readout chips to the silicon pixel sensors. We have previously reported large-scale tests of the yield using both indium and Pb/Sn solder bump [1]. The conclusion is that both seem to be viable for pixel detectors. We have also carried out studies of various effects (e.g. storage over long period, effect of heating and cooling, and radiation) on both types of bump bonds using daisy-chained parts on a small scale [2], [3]. Overall, these tests showed little changes in the integrity of the bump connections. Nevertheless, questions still remain on the long-term reliability of the bumps due to thermal cycle effects, attachment to a substrate with a different coefficient of thermal expansion (CTE), and radiation.

  20. Ultra precision and reliable bonding method

    NASA Technical Reports Server (NTRS)

    Gwo, Dz-Hung (Inventor)

    2001-01-01

    The bonding of two materials through hydroxide-catalyzed hydration/dehydration is achieved at room temperature by applying hydroxide ions to at least one of the two bonding surfaces and by placing the surfaces sufficiently close to each other to form a chemical bond between them. The surfaces may be placed sufficiently close to each other by simply placing one surface on top of the other. A silicate material may also be used as a filling material to help fill gaps between the surfaces caused by surface figure mismatches. A powder of a silica-based or silica-containing material may also be used as an additional filling material. The hydroxide-catalyzed bonding method forms bonds which are not only as precise and transparent as optical contact bonds, but also as strong and reliable as high-temperature frit bonds. The hydroxide-catalyzed bonding method is also simple and inexpensive.

  1. 25 CFR 214.4 - Bonds.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... MINING, EXCEPT OIL AND GAS § 214.4 Bonds. Lessee shall furnish with each lease at the time it is filed... consent of the Indian landowner may authorize a bond for a lesser amount if, in his opinion,...

  2. 25 CFR 214.4 - Bonds.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... MINING, EXCEPT OIL AND GAS § 214.4 Bonds. Lessee shall furnish with each lease at the time it is filed... consent of the Indian landowner may authorize a bond for a lesser amount if, in his opinion,...

  3. Clarifying Chemical Bonding. Overcoming Our Misconceptions.

    ERIC Educational Resources Information Center

    Hapkiewicz, Annis

    1991-01-01

    Demonstrations to help students change their misconceptions about chemical bond breaking are presented. Students' misconceptions about chemical bonds in both biological and chemical systems are discussed. A calculation for the release of energy from respiration is presented. (KR)

  4. 36 CFR 223.35 - Performance bond.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... DISPOSAL OF NATIONAL FOREST SYSTEM TIMBER Timber Sale Contracts Contract Conditions and Provisions § 223.35 Performance bond. Timber sale contracts may require the purchaser to furnish a performance bond...

  5. G. N. Lewis and the Chemical Bond.

    ERIC Educational Resources Information Center

    Pauling, Linus

    1984-01-01

    Discusses the contributions of G. N. Lewis to chemistry, focusing on his formulation of the basic principle of the chemical bond--the idea that the chemical bond consists of a pair of electrons held jointly by two atoms. (JN)

  6. Analysis of "Kiss" Bonds Between Composite Laminates

    NASA Astrophysics Data System (ADS)

    Poveromo, Scott L.; Earthman, James C.

    2014-06-01

    One of the leading challenges to designing lightweight, cost-effective bonded structures is to detect low shear strength "kiss" bonds where no other defects such as voids and cracks exist. To develop a nondestructive testing method that is sensitive to kiss bonds, standards need to be fabricated with known strength values. In the current work, we attempt to create kiss bonds in between carbon fiber composite laminates that have been bonded with epoxy film adhesive and epoxy paste adhesive. Based on ultrasonic testing, when creating true kiss bonds using film adhesives, a complete disbond could not be avoided because of thermally induced stresses during the high-temperature cure. However, further work demonstrated that kiss bonds can be formed using room-temperature curable epoxy paste adhesives by creating an amine blush on the epoxy surface or applying a release agent on the bonding surfaces.

  7. Approaching improved adhesive bonding repeatability

    NASA Astrophysics Data System (ADS)

    Schlette, Christian; Müller, Tobias; Roβmann, Jürgen; Brecher, Christian

    2016-03-01

    Today, the precision of micro-optics assembly is mostly limited by the accuracy of the bonding process ― and in the case of adhesive bonding by the prediction and compensation of adhesive shrinkage during curing. In this contribution, we present a novel approach to address adhesive bonding based on hybrid control system theory. In hybrid control, dynamic systems are described as "plants" which produce discrete and/or continuous outputs from given discrete and/or continuous inputs, thus yielding a hybrid state space description of the system. The task of hybrid controllers is to observe the plant and to generate a discrete and/or continuous input sequence that guides or holds the plant in a desired target state region while avoiding invalid or unwanted intermediate states. Our approach is based on a series of experiments carried out in order to analyze, define and decouple the dependencies of adhesive shrinkage on multiple parameters, such as application geometries, fixture forces and UV intensities. As some of the dependencies describe continuous effects (e.g. shrinkage from UV intensity) and other dependencies describe discrete state transitions (e.g. fixture removal during curing), the resulting model of the overall bonding process is a hybrid dynamic system in the general case. For this plant model, we then propose a concept of sampling-based parameter search as a basis to design suitable hybrid controllers, which have the potential to optimize process control for a selection of assembly steps, thus improving the repeatability of related production steps like beam-shaping optics or mounting of turning mirrors for fiber coupling.

  8. "Densified" tiles form stronger bonds

    NASA Technical Reports Server (NTRS)

    Dotts, R. L.; Holt, J. W.

    1981-01-01

    Application of colloidal silica more than doubles bond strength of ceramic tile/substrate attachments. "Densification" process strengthens surface where tile attaches to felt strain-isolator pad, redistributing stresses and preventing failures at that point. First, isopropyl alcohol is applied to bottom tile surface. Second, aqueous mixture of cementing colloidal silica and reinforcing ball-milled silica particles is painted on tile. Finally, after drying, tile is rewaterproofed by exposure to vapors or methyltrimethoxysilane and acetic acid.

  9. Bond Percolation on Multiplex Networks

    NASA Astrophysics Data System (ADS)

    Hackett, A.; Cellai, D.; Gómez, S.; Arenas, A.; Gleeson, J. P.

    2016-04-01

    We present an analytical approach for bond percolation on multiplex networks and use it to determine the expected size of the giant connected component and the value of the critical bond occupation probability in these networks. We advocate the relevance of these tools to the modeling of multilayer robustness and contribute to the debate on whether any benefit is to be yielded from studying a full multiplex structure as opposed to its monoplex projection, especially in the seemingly irrelevant case of a bond occupation probability that does not depend on the layer. Although we find that in many cases the predictions of our theory for multiplex networks coincide with previously derived results for monoplex networks, we also uncover the remarkable result that for a certain class of multiplex networks, well described by our theory, new critical phenomena occur as multiple percolation phase transitions are present. We provide an instance of this phenomenon in a multiplex network constructed from London rail and European air transportation data sets.

  10. Evaluation of Shear Bond Strength of Newer Bonding Systems on Superficial and Deep Dentin

    PubMed Central

    Kumari, R Veena; Siddaraju, Kishore; Nagaraj, Hema; Poluri, Ramya Krishna

    2015-01-01

    Background: The purpose of this study was to compare the shear bond strength of nanocomposite resin to superficial dentin and deep dentin using two different dentin bonding systems. Materials and Methods: All teeth were sectioned at various levels (superficial dentin: Dentin within 0.5-1 mm of dentinoenamel junction; deep dentin: Dentin within 0.5 mm of the highest pulp horn) using a Carborundum Disc and embedded in acrylic block of specific size. Selected specimens (60 premolar teeth) were grouped randomly into three groups, the groups were differentiated into superficial dentin, deep dentin, and control group which were further divided into sub Group A and Subgroup B containing 10 teeth each, depending on the bonding agents used. In Subgroup A, Tetric N Bond, and in Subgroup B Single Bond Universal were used. In the control group no bonding agent was used. The specimens were thermocycled for 500 cycles between 5°C and 55°C water bath for 40 s. Finally, the specimens were subjected to shear bond strength study under INSTRON machine (Universal Testing Machine). The maximum shear bond strengths were noted at the time of fracture (de-bonding) of the restorative material. Results were analyzed using ANOVA test, Bonferroni test, and paired t-test. Results: Bond strength values of fifth generation bonding system (Tetric N Bond) showed higher mean shear bond strength compared to seventh generation bonding system (Single Bond Universal). There was a significant fall in bond strength values as one reaches deeper levels of dentin from superficial to deep dentin. Conclusion: There was a significant difference between the bond strength of fifth generation bonding system (Tetric N Bond) and seventh generation bonding system (Single Bond Universal). Decrease in the bond strength values is seen for the deeper level of dentin as compared to superficial dentin. PMID:26435613

  11. Hot gas stream application in micro-bonding technique

    NASA Astrophysics Data System (ADS)

    Andrijasevic, Daniela; Giouroudi, Ioanna; Smetana, Walter; Boehm, Stefan; Brenner, Werner

    2006-01-01

    This paper presents a new concept for bonding micro-parts with dimensions in the range of 50 μm to 300 μm. Two different kinds of adhesives - polyurethane adhesive foil and hot melt glue - were applied to a basic substrate by different techniques. The focused and concentrated hot gas stream softened glue which had been applied in a solid state. Micro-parts were then embossed in the softened glue, or covered and shielded by it. In this way, a rigid and compact bond was obtained after cooling. For the positioning of micro-parts (optical fibers), it has been necessary to manufacture adequate V-grooves. Finite element analyses using the ANSYS TM program package were performed in order to evaluate parameters which govern the heat transfer to the adhesive and substrate respectively. Experimental results are in good agreement with results obtained by the numerical simulations. The advantages of this new approach are small system size, low capital costs, simple usage, applicability to many material combinations, easy integration into existing production lines, etc.

  12. Cleanliness inspection tool for RSRM bond surfaces

    NASA Astrophysics Data System (ADS)

    Mattes, Robert A.

    1995-03-01

    Using optically stimulated electron emission (OSEE), Thiokol has monitored bond surfaces in process for contamination on the Redesigned Solid Rocket Motor (RSRM). This technique provides process control information to help assure bond surface quality and repeatability prior to bonding. This paper will describe OSEE theory of operation and the instrumentation implemented at Thiokol Corporation since 1987. Data from process hardware will be presented.

  13. Heat Bonding of Irradiated Ethylene Vinyl Acetate

    NASA Technical Reports Server (NTRS)

    Slack, D. H.

    1986-01-01

    Reliable method now available for joining parts of this difficult-tobond material. Heating fixture encircles ethylene vinyl acetate multiplesocket part, providing heat to it and to tubes inserted in it. Fixtures specially designed to match parts to be bonded. Tube-and-socket bonds made with this technique subjected to tensile tests. Bond strengths of 50 percent that of base material obtained consistently.

  14. 43 CFR 16.5 - Bonds.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Bonds. 16.5 Section 16.5 Public Lands: Interior Office of the Secretary of the Interior CONSERVATION OF HELIUM § 16.5 Bonds. The applicant shall be required to submit a bond in such amount and in such form as the Secretary may prescribe to...

  15. 43 CFR 16.5 - Bonds.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 1 2014-10-01 2014-10-01 false Bonds. 16.5 Section 16.5 Public Lands: Interior Office of the Secretary of the Interior CONSERVATION OF HELIUM § 16.5 Bonds. The applicant shall be required to submit a bond in such amount and in such form as the Secretary may prescribe to...

  16. 43 CFR 16.5 - Bonds.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 1 2013-10-01 2013-10-01 false Bonds. 16.5 Section 16.5 Public Lands: Interior Office of the Secretary of the Interior CONSERVATION OF HELIUM § 16.5 Bonds. The applicant shall be required to submit a bond in such amount and in such form as the Secretary may prescribe to...

  17. 27 CFR 19.516 - Bond account.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... maximum penal sum, he shall maintain an account of his bond and he shall charge the bond with the amount... return. Where a bond in less than the maximum penal sum has been allocated among two or more plants, as... the penal sum allocated to that plant. (Sec. 201, Pub. L. 85-859, 72 Stat. 1356, as amended (26...

  18. 27 CFR 19.243 - Withdrawal bond.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... to each plant covered by the bond the part of the total sum which represents the penal sum (computed in accordance with § 19.245) for each such plant. If the penal sum of the bond covering a plant, or the penal sum allocated to any plant (where the bond covers more than one plant), is in an amount...

  19. 27 CFR 19.244 - Unit bond.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... sum which represents the penal sum (computed in accordance with § 19.245) for operations at and withdrawals from each plant. If the penal sum of the bond covering a plant, or the penal sum allocated to any... reflected by the penal sum in the bond for such plant. The unit bond shall be conditioned that the...

  20. 8 CFR 103.6 - Surety bonds.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... acceptable surety. (c) Cancellation—(1) Public charge bonds. A public charge bond posted for an immigrant..., provided the immigrant did not become a public charge prior to death, departure, or naturalization. The district director may cancel a public charge bond at any time if he/she finds that the immigrant is...

  1. 8 CFR 103.6 - Surety bonds.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... acceptable surety. (c) Cancellation—(1) Public charge bonds. A public charge bond posted for an immigrant..., provided the immigrant did not become a public charge prior to death, departure, or naturalization. The district director may cancel a public charge bond at any time if he/she finds that the immigrant is...

  2. 36 CFR 228.51 - Bonding.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 36 Parks, Forests, and Public Property 2 2012-07-01 2012-07-01 false Bonding. 228.51 Section 228.51 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE MINERALS Disposal of Mineral Materials General Provisions § 228.51 Bonding. (a) Bond requirements. Before operations may...

  3. Bonding Heat-Resistant Fabric to Tile

    NASA Technical Reports Server (NTRS)

    Holt, J. W.; Smiser, L. W.

    1985-01-01

    Acid etching, densification, and silica cement ensure strong bond. Key step in preparation for bonding to glazed tile is etching quartz fabric and tile with acid. This increases adhesion of silica cement used to form bond. Procedures use high-temperature materials exclusively and therefore suitable for securing flexible seals and heat barriers around doors and viewing ports in furnaces and kilns.

  4. Halogen Bonding in Hypervalent Iodine Compounds.

    PubMed

    Catalano, Luca; Cavallo, Gabriella; Metrangolo, Pierangelo; Resnati, Giuseppe; Terraneo, Giancarlo

    2016-01-01

    Halogen bonds occur when electrophilic halogens (Lewis acids) attractively interact with donors of electron density (Lewis bases). This term is commonly used for interactions undertaken by monovalent halogen derivatives. The aim of this chapter is to show that the geometric features of the bonding pattern around iodine in its hypervalent derivatives justify the understanding of some of the longer bonds as halogen bonds. We suggest that interactions directionality in ionic and neutral λ(3)-iodane derivatives is evidence that the electron density distribution around iodine atoms is anisotropic, a region of most positive electrostatic potential exists on the extensions of the covalent bonds formed by iodine, and these positive caps affect, or even determine, the crystal packing of these derivatives. For instance, the short cation-anion contacts in ionic λ(3)-iodane and λ(5)-iodane derivatives fully match the halogen bond definition and geometrical prerequisites. The same holds for the short contacts the cation of ionic λ(3)-iodanes forms with lone-pair donors or the short contacts given by neutral λ(3)-iodanes with incoming nucleophiles. The longer and weaker bonds formed by iodine in hypervalent compounds are usually called secondary bondings and we propose that the term halogen bond can also be used. Compared to the term secondary bond, halogen bond may possibly be more descriptive of some bonding features, e.g., its directionality and the relationships between structure of interacting groups and interaction strength. PMID:26809623

  5. Valence-Bond Theory and Chemical Structure.

    ERIC Educational Resources Information Center

    Klein, Douglas J.; Trinajstic, Nenad

    1990-01-01

    Discussed is the importance of valence bond theory on the quantum-mechanical theory of chemical structure and the nature of the chemical bond. Described briefly are early VB theory, development of VB theory, modern versions, solid-state applications, models, treatment in textbooks, and flaws in criticisms of valence bond theory. (KR)

  6. A Model for the Chemical Bond

    ERIC Educational Resources Information Center

    Magnasco, Valerio

    2004-01-01

    Bond stereochemistry in polyatomic hydrides is explained in terms of the principle of bond energies maximization, which yields X-H straight bonds and suggests the formation of appropriate sp hybrids on the central atom. An introduction to the electron charge distribution in molecules is given, and atomic, overlap, gross and formal charges are…

  7. 43 CFR 16.5 - Bonds.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Bonds. 16.5 Section 16.5 Public Lands: Interior Office of the Secretary of the Interior CONSERVATION OF HELIUM § 16.5 Bonds. The applicant shall be required to submit a bond in such amount and in such form as the Secretary may prescribe to...

  8. 43 CFR 16.5 - Bonds.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Bonds. 16.5 Section 16.5 Public Lands: Interior Office of the Secretary of the Interior CONSERVATION OF HELIUM § 16.5 Bonds. The applicant shall be required to submit a bond in such amount and in such form as the Secretary may prescribe to...

  9. 36 CFR 228.51 - Bonding.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 2 2013-07-01 2013-07-01 false Bonding. 228.51 Section 228.51 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE MINERALS Disposal of Mineral Materials General Provisions § 228.51 Bonding. (a) Bond requirements. Before operations may...

  10. 30 CFR 800.20 - Surety bonds.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR BONDING AND INSURANCE REQUIREMENTS FOR SURFACE COAL MINING AND RECLAMATION OPERATIONS BOND AND INSURANCE REQUIREMENTS FOR SURFACE COAL MINING AND RECLAMATION OPERATIONS UNDER REGULATORY PROGRAMS § 800.20 Surety bonds....

  11. 30 CFR 800.20 - Surety bonds.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Resources OFFICE OF SURFACE MINING RECLAMATION AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR BONDING AND INSURANCE REQUIREMENTS FOR SURFACE COAL MINING AND RECLAMATION OPERATIONS BOND AND INSURANCE REQUIREMENTS FOR SURFACE COAL MINING AND RECLAMATION OPERATIONS UNDER REGULATORY PROGRAMS § 800.20 Surety bonds....

  12. 25 CFR 163.21 - Bonds required.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 25 Indians 1 2012-04-01 2011-04-01 true Bonds required. 163.21 Section 163.21 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GENERAL FORESTRY REGULATIONS Forest Management and Operations § 163.21 Bonds required. (a) Performance bonds will be required in connection with...

  13. 25 CFR 163.21 - Bonds required.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 25 Indians 1 2014-04-01 2014-04-01 false Bonds required. 163.21 Section 163.21 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GENERAL FORESTRY REGULATIONS Forest Management and Operations § 163.21 Bonds required. (a) Performance bonds will be required in connection with...

  14. 25 CFR 163.21 - Bonds required.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 25 Indians 1 2011-04-01 2011-04-01 false Bonds required. 163.21 Section 163.21 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GENERAL FORESTRY REGULATIONS Forest Management and Operations § 163.21 Bonds required. (a) Performance bonds will be required in connection with...

  15. 25 CFR 163.21 - Bonds required.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Bonds required. 163.21 Section 163.21 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GENERAL FORESTRY REGULATIONS Forest Management and Operations § 163.21 Bonds required. (a) Performance bonds will be required in connection with...

  16. 25 CFR 163.21 - Bonds required.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 25 Indians 1 2013-04-01 2013-04-01 false Bonds required. 163.21 Section 163.21 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER GENERAL FORESTRY REGULATIONS Forest Management and Operations § 163.21 Bonds required. (a) Performance bonds will be required in connection with...

  17. 30 CFR 256.53 - Additional bonds.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Additional bonds. 256.53 Section 256.53 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE LEASING OF SULPHUR OR OIL AND GAS IN THE OUTER CONTINENTAL SHELF Bonding § 256.53 Additional bonds. (a) This paragraph explains...

  18. Cleanliness inspection tool for RSRM bond surfaces

    NASA Technical Reports Server (NTRS)

    Mattes, Robert A.

    1995-01-01

    Using optically stimulated electron emission (OSEE), Thiokol has monitored bond surfaces in process for contamination on the Redesigned Solid Rocket Motor (RSRM). This technique provides process control information to help assure bond surface quality and repeatability prior to bonding. This paper will describe OSEE theory of operation and the instrumentation implemented at Thiokol Corporation since 1987. Data from process hardware will be presented.

  19. Bonding and Joining Technology: a Compilation

    NASA Technical Reports Server (NTRS)

    1971-01-01

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

  20. Oregon School Bond Manual. Seventh Edition.

    ERIC Educational Resources Information Center

    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 district bonds. The manual deals with the three primary types of Oregon school district borrowings: (1) general obligation bonds; (2) tax and revenue anticipation notes; and…

  1. 27 CFR 70.282 - Single bond in lieu of multiple bonds.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Single bond in lieu of multiple bonds. 70.282 Section 70.282 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... ADMINISTRATION Collection of Excise and Special (Occupational) Tax Bonds § 70.282 Single bond in lieu of...

  2. Two-center two-electron covalent bonds with deficient bonding densities.

    PubMed

    Yang, Yang

    2012-10-18

    Electron-deficient covalent bonds are a type of covalent bonds without electron accumulation at their bonding regions. Compared with normal covalent bonds, they are quite sensitive to chemical environments. Electron-deficient and normal covalent bonds are not isolated from each other. An electron-deficient bond may change to a normal one upon the change of substituting groups. Neither bond elongation nor atom electronegativity is directly related to the electron deficiency in an electron-deficient bond. Atoms in molecules (AIM) analyses suggest that electron-deficient bonds are characterized by positive Laplacians and small ρ(BCP) values. The positive Laplacian is caused by insignificant electron accumulation perpendicular to the bond path. On the basis of electron localization function (ELF) descriptors, electron-deficient bonds have small basin populations, low η values and high relative fluctuations. There may be one or two bond basins for an electron-deficient bond. In addition, such a bond may correlate with two more valence basins close to the two participating atoms. Electron-deficient bonds are usually weak and long. This is consistent with the low s characters in their natural bond orbitals (NBOs).

  3. 48 CFR 28.106-1 - Bonds and bond related forms.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Bid Bond (see 28.001). (g) SF 35, Annual Performance Bond (see 28.104). (h) SF 273, Reinsurance... forms. 28.106-1 Section 28.106-1 Federal Acquisition Regulations System FEDERAL ACQUISITION REGULATION GENERAL CONTRACTING REQUIREMENTS BONDS AND INSURANCE Bonds and Other Financial Protections 28.106-1...

  4. 19 CFR 125.32 - Merchandise delivered to a bonded store or bonded warehouse.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... warehouse. 125.32 Section 125.32 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND... Merchandise delivered to a bonded store or bonded warehouse. When merchandise is carried, carted or lightered to and received in a bonded store or bonded warehouse, the proprietor or his representative...

  5. Hexacoordinate bonding and aromaticity in silicon phthalocyanine.

    PubMed

    Yang, Yang

    2010-12-23

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

  6. Weld bonding of titanium with polyimide adhesives

    NASA Technical Reports Server (NTRS)

    Vaughan, R. W.; Sheppard, C. H.; Orell, M. K.

    1975-01-01

    A conductive adhesive primer and a capillary flow adhesive were developed for weld bonding titanium alloy joints. Both formulations contained ingredients considered to be non-carcinogenic. Lap-shear joint test specimens and stringer-stiffened panels were weld bonded using a capillary flow process to apply the adhesive. Static property information was generated for weld bonded joints over the temperature range of 219K (-65 F) to 561K (550 F). The capillary flow process was demonstrated to produce weld bonded joints of equal strength to the weld through weld bonding process developed previously.

  7. Antibacterial activity of four dentin bonding systems.

    PubMed

    Herrera, M; Carrión, P; Bravo, M; Castillo, A

    2000-08-01

    The antibacterial action of bonding systems Gluma 2000, Syntac, Prisma Universal Bond 3, Scotchbond Multipurpose and Prime-Bond was tested against 32 strains of the caries-producing bacteria Streptococcus spp., Lactobacillus spp., Actinomyces spp., Porphyromonas spp. and Clostridium spp. An agar plate diffusion method was used with chlorhexidine as the positive control. Assays were performed in triplicate for each component (primer and adhesive) of the bonding systems. All the adhesives were found to inhibit bacterial growth but with differences in their spectra of action. The sum action of the Scotchbond Multipurpose components were most inhibitory and Prime-Bond was found to be the least effective system.

  8. Copper Wire Bonding Concerns and Best Practices

    NASA Astrophysics Data System (ADS)

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

    2013-08-01

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

  9. Trimethylaluminum: Bonding by Charge and Current Topology.

    PubMed

    Stammler, Hans-Georg; Blomeyer, Sebastian; Berger, Raphael J F; Mitzel, Norbert W

    2015-11-01

    The charge density distribution of the trimethylaluminum dimer was determined by high-angle X-ray diffraction of a single crystal and quantum-chemical methods and analyzed using the quantum theory of atoms in molecules. The data can be interpreted as Al2Me6 being predominantly ionically bonded, with clear indications of topological asymmetry for the bridging Al-C bonds owing to delocalized multicenter bonding. This interpretation is supported by the calculated magnetic response currents. The data shed new light on the bonding situation in this basic organometallic molecule, which was previously described by contradicting interpretations of bonding.

  10. Classical model of negative thermal expansion in solids with expanding bonds

    NASA Astrophysics Data System (ADS)

    Schick, Joseph T.; Rappe, Andrew M.

    2016-06-01

    We study negative thermal expansion (NTE) in model lattices with multiple atoms per cell and first- and second-nearest neighbor interactions using the (anharmonic) Morse potential. By exploring the phase space of neighbor distances and thermal expansion rates of the bonds, we determine the conditions under which NTE emerges. By permitting all bond lengths to expand at different rates, we find that NTE is possible without appealing to fully rigid units. Nearly constant, large-amplitude, isotropic NTE is observed up to the melting temperature in a classical molecular dynamics model of a ReO3-like structure when the rigidity of octahedral units is almost completely eliminated. Only weak NTE, changing over to positive expansion, is observed when the corner-linked octahedra are rigid, with flexible second-neighbor bonds between neighboring octahedra permitting easy rotation. We observe similar changes to thermal expansion behavior for the diamond lattice: NTE when second-neighbor interactions are weak to positive thermal expansion when second-neighbor interactions are strong. From these observations, we suggest that the only essential local conditions for NTE are atoms with low coordination numbers along with very low energies for changing bond angles relative to bond-stretching energies.

  11. On The Nature of the Halogen Bond.

    PubMed

    Wang, Changwei; Danovich, David; Mo, Yirong; Shaik, Sason

    2014-09-01

    The wide-ranging applications of the halogen bond (X-bond), notably in self-assembling materials and medicinal chemistry, have placed this weak intermolecular interaction in a center of great deal of attention. There is a need to elucidate the physical nature of the halogen bond for better understanding of its similarity and differences vis-à-vis other weak intermolecular interactions, for example, hydrogen bond, as well as for developing improved force-fields to simulate nano- and biomaterials involving X-bonds. This understanding is the focus of the present study that combines the insights of a bottom-up approach based on ab initio valence bond (VB) theory and the block-localized wave function (BLW) theory that uses monomers to reconstruct the wave function of a complex. To this end and with an aim of unification, we studied the nature of X-bonds in 55 complexes using the combination of VB and BLW theories. Our conclusion is clear-cut; most of the X-bonds are held by charge transfer interactions (i.e., intermolecular hyperconjugation) as envisioned more than 60 years ago by Mulliken. This is consistent with the experimental and computational findings that X-bonds are more directional than H-bonds. Furthermore, the good linear correlation between charge transfer energies and total interaction energies partially accounts for the success of simple force fields in the simulation of large systems involving X-bonds. PMID:26588518

  12. Long Range Bond-Bond Correlations in Dense Polymer Solutions

    NASA Astrophysics Data System (ADS)

    Wittmer, J. P.; Meyer, H.; Baschnagel, J.; Johner, A.; Obukhov, S.; Mattioni, L.; Müller, M.; Semenov, A. N.

    2004-09-01

    The scaling of the bond-bond correlation function P1(s) along linear polymer chains is investigated with respect to the curvilinear distance s along the flexible chain and the monomer density ρ via Monte Carlo and molecular dynamics simulations. Surprisingly, the correlations in dense three-dimensional solutions are found to decay with a power law P1(s)˜s-ω with ω=3/2 and the exponential behavior commonly assumed is clearly ruled out for long chains. In semidilute solutions, the density dependent scaling of P1(s)≈g-ω0(s/g)-ω with ω0=2-2ν=0.824 (ν=0.588 being Flory's exponent) is set by the number of monomers g(ρ) in an excluded volume blob. Our computational findings compare well with simple scaling arguments and perturbation calculation. The power-law behavior is due to self-interactions of chains caused by the chain connectivity and the incompressibility of the melt.

  13. Chemical Bonding in Sulfide Minerals

    SciTech Connect

    Vaughan, David J.; Rosso, Kevin M.

    2006-08-01

    An understanding of chemical bonding and electronic structure in sulfide minerals is central to any attempt at understanding their crystal structures, stabilities and physical properties. It is also an essential precursor to understanding reactivity through modeling surface structure at the molecular scale. In recent decades, there have been remarkable advances in first principles (ab initio) methods for the quantitative calculation of electronic structure. These advances have been made possible by the very rapid development of high performance computers. Several review volumes that chart the applications of these developments in mineralogy and geochemistry are available (Tossell and Vaughan, 1992; Cygan and Kubicki, 2001). An important feature of the sulfide minerals is the diversity of their electronic structures, as evidenced by their electrical and magnetic properties (see Pearce et al. 2006, this volume). Thus, sulfide minerals range from insulators through semiconductors to metals, and exhibit every type of magnetic behavior. This has presented problems for those attempting to develop bonding models for sulfides, and also led to certain misconceptions regarding the kinds of models that may be appropriate. In this chapter, chemical bonding and electronic structure models for sulfides are reviewed with emphasis on more recent developments. Although the fully ab initio quantitative methods are now capable of a remarkable degree of sophistication in terms of agreement with experiment and potential to interpret and predict behavior with varying conditions, both qualitative and more simplistic quantitative approaches will also be briefly discussed. This is because we believe that the insights which they provide are still helpful to those studying sulfide minerals. In addition to the application of electronic structure models and calculations to solid sulfides, work on sulfide mineral surfaces (Rosso and Vaughan 2006a,b) and solution complexes and clusters (Rickard

  14. An Easy Access to Organic Salt-Based Stimuli-Responsive and Multifunctional Supramolecular Hydrogels.

    PubMed

    Majumder, Joydeb; Dastidar, Parthasarathi

    2016-06-27

    By exploiting orthogonal hydrogen bonding involving supramolecular synthons and hydrophobic/hydrophilic interactions, a new series of simple organic salt based hydrogelators derived from pyrene butyric acid and its β-alanine amide derivative, and various primary amines has been achieved. The hydrogels were characterised by microscopy, table-top rheology and dynamic rheology. FTIR, variable-temperature (1) H NMR and emission spectroscopy established the role of various supramolecular interactions such as hydrogen bonding and π-π stacking in hydrogelation. Single-crystal X-ray diffraction (SXRD) studies supported the conclusion that orthogonal hydrogen bonding involving amide-amide and primary ammonium monocarboxylate (PAM) synthons indeed played a crucial role in hydrogelation. The hydrogels were found to be stimuli-responsive and were capable of sensing ammonia and adsorbing water-soluble dye (methylene blue). All the hydrogelators were biocompatible (MTT assay in RAW 264.7 cells), indicating their suitability for use in drug delivery. PMID:27258667

  15. Fabric softeners: nearly instantaneous characterization and quality control of cationic surfactants by easy ambient sonic-spray ionization mass spectrometry.

    PubMed

    Saraiva, Sérgio A; Abdelnur, Patrícia V; Catharino, Rodrigo R; Nunes, George; Eberlin, Marcos N

    2009-02-01

    A tiny droplet of typical samples of fabric softeners from different commercial brands placed on a smooth paper surface was subjected to easy ambient sonic-spray ionization mass spectrometry (EASI-MS). With no need for sample-preparation or pre-separation procedures, EASI-MS and EASI-MS/MS identify nearly instantaneously the main surfactants and the homologous series employed in their formulations. Adulterated and low quality samples containing no or less efficient softeners are also easily recognized. PMID:19127530

  16. Bonds that strengthen under force

    NASA Astrophysics Data System (ADS)

    Vogel, Viola

    2006-03-01

    While the adhesive strength of most receptor-ligand interactions is exponentially reduced if strained, some receptor-ligand complexes exist that strengthen under force which is the hallmark of catch bonds. Although the existence of catch bonds was theoretically predicted, the first experimental demonstrations of their existence were given only recently, i.e. for the bacterial adhesin FimH that is located at the tip of type I fimbriae of E. coli and for p-selectin. In a major collaborative effort, we studied the structural origin by which the FimH-mannose bond is switched by force to a high binding state. Mutational studies were thereby combined with steered molecular dynamic simulations to decipher how force might affect protein conformation. Force-activation of FimH leads to a complex `stick-and-roll' bacterial adhesion behavior in which E. coli preferentially rolls over mannosylated surfaces at low shear but increasingly sticks firmly as the shear is increased. Interesting similarities are further seen if comparing the structural mechanisms by which liganded FimH and liganded integrins are switched to a high binding state. This comparison was made possible by docking fibronectin's 10^th type III module (fnIII10) to αVβ3 integrin. αVβ3 can switch from the ``closed'' αVβ3 integrin headpiece to the ``open'' conformation by opening the hinge angle between the βA domain and the hybrid domain of the β-integrin. The ``open'' state has been implicated by many experimental laboratories to correspond to the activated state of integrins. W. E. Thomas, E. Trintchina, M. Forero, V. Vogel, E. Sokurenko, Bacterial adhesion to target cells enhanced by shear-force, Cell, 109 (2002) 913. W. E. Thomas, L. M. Nilsson, M. Forero, E. V. Sokurenko, V. Vogel, Shear-dependent `stick-and-roll' adhesion of type 1 fimbriated Escherichia coli, Molecular Microbiology 53 (2004) 1545. W. Thomas, M. Forero, O. Yakovenko, L. Nilsson, P. Vicini, E. Sokurenko, V. Vogel, Catch Bond Model

  17. Bonded and Stitched Composite Structure

    NASA Technical Reports Server (NTRS)

    Zalewski, Bart F. (Inventor); Dial, William B. (Inventor)

    2014-01-01

    A method of forming a composite structure can include providing a plurality of composite panels of material, each composite panel having a plurality of holes extending through the panel. An adhesive layer is applied to each composite panel and a adjoining layer is applied over the adhesive layer. The method also includes stitching the composite panels, adhesive layer, and adjoining layer together by passing a length of a flexible connecting element into the plurality of holes in the composite panels of material. At least the adhesive layer is cured to bond the composite panels together and thereby form the composite structure.

  18. UNICON: A Powerful and Easy-to-Use Compound Library Converter.

    PubMed

    Sommer, Kai; Friedrich, Nils-Ole; Bietz, Stefan; Hilbig, Matthias; Inhester, Therese; Rarey, Matthias

    2016-06-27

    The accurate handling of different chemical file formats and the consistent conversion between them play important roles for calculations in complex cheminformatics workflows. Working with different cheminformatic tools often makes the conversion between file formats a mandatory step. Such a conversion might become a difficult task in cases where the information content substantially differs. This paper describes UNICON, an easy-to-use software tool for this task. The functionality of UNICON ranges from file conversion between standard formats SDF, MOL2, SMILES, PDB, and PDBx/mmCIF via the generation of 2D structure coordinates and 3D structures to the enumeration of tautomeric forms, protonation states, and conformer ensembles. For this purpose, UNICON bundles the key elements of the previously described NAOMI library in a single, easy-to-use command line tool.

  19. Influence of thermal agitation on the electric field induced precessional magnetization reversal with perpendicular easy axis

    SciTech Connect

    Cheng, Hongguang Deng, Ning

    2013-12-15

    We investigated the influence of thermal agitation on the electric field induced precessional magnetization switching probability with perpendicular easy axis by solving the Fokker-Planck equation numerically with finite difference method. The calculated results show that the thermal agitation during the reversal process crucially influences the switching probability. The switching probability can be achieved is only determined by the thermal stability factor Δ of the free layer, it is independent on the device dimension, which is important for the high density device application. Ultra-low error rate down to the order of 10{sup −9} can be achieved for the device of thermal stability factor Δ of 40. Low damping factor α material should be used for the free layer for high reliability device applications. These results exhibit potential of electric field induced precessional magnetization switching with perpendicular easy axis for ultra-low power, high speed and high density magnetic random access memory (MRAM) applications.

  20. Second Interim Report NASA - easyJet Collaboration on the Human Factors Monitoring Program (HFMP) Study

    NASA Technical Reports Server (NTRS)

    Srivistava, Ashok N.; Barton, Phil

    2012-01-01

    This is the second interim report jointly prepared by NASA and easyJet on the work performed under the agreement to collaborate on a study of the factors entailed in flight and cabin-crew fatigue, and decreases in performance associated with fatigue. The objective of this Agreement is to generate reliable procedures that aid in understanding the levels and characteristics of flight and cabin-crew fatigue factors, both latent and proximate, whose confluence will likely result in unacceptable crew performance. This study entails the analyses of numerical and textual data collected during operational flights. NASA and easyJet are both interested in assessing and testing NASA s automated capabilities for extracting operationally significant information from very large, diverse (textual and numerical) databases; much larger than can be handled practically by human experts.

  1. Easy and direct method for calibrating atomic force microscopy lateral force measurements.

    PubMed

    Liu, Wenhua; Bonin, Keith; Guthold, Martin

    2007-06-01

    We have designed and tested a new, inexpensive, easy-to-make and easy-to-use calibration standard for atomic force microscopy (AFM) lateral force measurements. This new standard simply consists of a small glass fiber of known dimensions and Young's modulus, which is fixed at one end to a substrate and which can be bent laterally with the AFM tip at the other end. This standard has equal or less error than the commonly used method of using beam mechanics to determine a cantilever's lateral force constant. It is transferable, thus providing a universal tool for comparing the calibrations of different instruments. It does not require knowledge of the cantilever dimensions and composition or its tip height. This standard also allows direct conversion of the photodiode signal to force and, thus, circumvents the requirement for a sensor response (sensitivity) measurement.

  2. Easy Fabrication of Thin Membranes with Through Holes. Application to Protein Patterning

    PubMed Central

    Arasi, Bakya; Gauthier, Nils; Viasnoff, Virgile

    2012-01-01

    Since protein patterning on 2D surfaces has emerged as an important tool in cell biology, the development of easy patterning methods has gained importance in biology labs. In this paper we present a simple, rapid and reliable technique to fabricate thin layers of UV curable polymer with through holes. These membranes are as easy to fabricate as microcontact printing stamps and can be readily used for stencil patterning. We show how this microfabrication scheme allows highly reproducible and highly homogeneous protein patterning with micron sized resolution on surfaces as large as 10 cm2. Using these stencils, fragile proteins were patterned without loss of function in a fully hydrated state. We further demonstrate how intricate patterns of multiple proteins can be achieved by stacking the stencil membranes. We termed this approach microserigraphy. PMID:22952944

  3. Magnetization process in holmium: easy axis spin reorientation induced by the magnetostrictive basal plane distortion.

    PubMed

    Benito, L; Ciria, M; de la Fuente, C; Arnaudas, J I; Ward, R C C; Wells, M R

    2005-06-10

    We report on the change of the easy axis direction in holmium, from the a to the b axis, under the application of a magnetic field in the basal plane. This spin reorientation is observed by measuring the magnetic torque in Ho(n)/Lu(15) superlattices (n and 15 are the number of atomic planes in the Ho and Lu blocks). We also observe that, at the field H0 and temperature at which the reorientation occurs, both axes are easy directions. Based on the fact that the field H0 depends on n in the same way as the field-induced magnetoelastic distortion does, we propose that this spin reorientation originates from the strong field-induced magnetoelastic deformation within the basal plane. The modulation of the alpha strains with sixfold symmetry originates a 12-fold term in the magnetic anisotropy energy.

  4. Easy fabrication of thin membranes with through holes. Application to protein patterning.

    PubMed

    Masters, Thomas; Engl, Wilfried; Weng, Zhe L; Arasi, Bakya; Gauthier, Nils; Viasnoff, Virgile

    2012-01-01

    Since protein patterning on 2D surfaces has emerged as an important tool in cell biology, the development of easy patterning methods has gained importance in biology labs. In this paper we present a simple, rapid and reliable technique to fabricate thin layers of UV curable polymer with through holes. These membranes are as easy to fabricate as microcontact printing stamps and can be readily used for stencil patterning. We show how this microfabrication scheme allows highly reproducible and highly homogeneous protein patterning with micron sized resolution on surfaces as large as 10 cm(2). Using these stencils, fragile proteins were patterned without loss of function in a fully hydrated state. We further demonstrate how intricate patterns of multiple proteins can be achieved by stacking the stencil membranes. We termed this approach microserigraphy. PMID:22952944

  5. NASA - easyJet Collaboration on the Human Factors Monitoring Program (HFMP) Study

    NASA Technical Reports Server (NTRS)

    Srivistava, Ashok N.; Barton, Phil

    2012-01-01

    This is the first annual report jointly prepared by NASA and easyJet on the work performed under the agreement to collaborate on a study of the many factors entailed in flight - and cabin-crew fatigue and documenting the decreases in performance associated with fatigue. The objective of this Agreement is to generate reliable, automated procedures that improve understanding of the levels and characteristics of flight - and cabin-crew fatigue factors, both latent and proximate, whose confluence will likely result in unacceptable flight crew performance. This study entails the analyses of numerical and textual data collected during operational flights. NASA and easyJet are both interested in assessing and testing NASA s automated capabilities for extracting operationally significant information from very large, diverse (textual and numerical) databases, much larger than can be handled practically by human experts.

  6. Overproduction and easy recovery of biofuels from engineered cyanobacteria, autolyzing multicellular cells.

    PubMed

    Yoshida, Satomi; Takahashi, Masatoshi; Ikeda, Ayae; Fukuda, Hirofumi; Kitazaki, Chifumi; Asayama, Munehiko

    2015-06-01

    The semi-filamentous multicellular cyanobacterium Limnothrix/Pseudanabaena sp. strain ABRG5-3 undergoes autolysis, which involves the accumulation of polyphosphate compounds and disintegration of thylakoid membranes in cells, as a unique feature that occurs due to growth conditions. In this study, the overexpression and easy recovery of alkane (a saturated hydrocarbon, C17H36) as a biofuel were examined in recombinants of the cyanobacteria ABRG5-3 and Synechocystis sp. strain PCC6803. The results obtained indicated that the accumulated mass of alkane accounted for ∼50 or 60% of the dry weight of ABRG5-3 or PCC6803 recombinant cells, respectively. Furthermore, cultivating cells in liquid medium BG11 in which the nitrogen resource had been depleted promoted the production of alkane and cell lysis, resulting in the easy recovery of target products from the supernatant. PMID:25661591

  7. sesC as a genetic marker for easy identification of Staphylococcus epidermidis from other isolates.

    PubMed

    Khodaparast, Ladan; Khodaparast, Laleh; Van Mellaert, Lieve; Shahrooei, Mohammad; Van Ranst, Marc; Van Eldere, Johan

    2016-09-01

    Staphylococcus epidermidis is one of the major concerns with respect to hospital-acquired infections. Therefore, a rapid and easy method to identify at species level S. epidermidis isolates out of a broad range of bacteria is necessary. Based on earlier studies, the sesC gene encoding a S. epidermidis surface protein revealed to be a highly conserved gene in this species. By means of an easy and inexpensive PCR assay, the presence of sesC was checked in 438 clinical staphylococcal isolates. Results showed that sesC is specifically present in all S. epidermidis. In conclusion, the sesC gene can be exploited as a genetic marker in order to distinguish S. epidermidis from other isolates.

  8. Overproduction and easy recovery of biofuels from engineered cyanobacteria, autolyzing multicellular cells.

    PubMed

    Yoshida, Satomi; Takahashi, Masatoshi; Ikeda, Ayae; Fukuda, Hirofumi; Kitazaki, Chifumi; Asayama, Munehiko

    2015-06-01

    The semi-filamentous multicellular cyanobacterium Limnothrix/Pseudanabaena sp. strain ABRG5-3 undergoes autolysis, which involves the accumulation of polyphosphate compounds and disintegration of thylakoid membranes in cells, as a unique feature that occurs due to growth conditions. In this study, the overexpression and easy recovery of alkane (a saturated hydrocarbon, C17H36) as a biofuel were examined in recombinants of the cyanobacteria ABRG5-3 and Synechocystis sp. strain PCC6803. The results obtained indicated that the accumulated mass of alkane accounted for ∼50 or 60% of the dry weight of ABRG5-3 or PCC6803 recombinant cells, respectively. Furthermore, cultivating cells in liquid medium BG11 in which the nitrogen resource had been depleted promoted the production of alkane and cell lysis, resulting in the easy recovery of target products from the supernatant.

  9. Easy and direct method for calibrating atomic force microscopy lateral force measurements

    PubMed Central

    Liu, Wenhua; Bonin, Keith; Guthold, Martin

    2010-01-01

    We have designed and tested a new, inexpensive, easy-to-make and easy-to-use calibration standard for atomic force microscopy (AFM) lateral force measurements. This new standard simply consists of a small glass fiber of known dimensions and Young’s modulus, which is fixed at one end to a substrate and which can be bent laterally with the AFM tip at the other end. This standard has equal or less error than the commonly used method of using beam mechanics to determine a cantilever’s lateral force constant. It is transferable, thus providing a universal tool for comparing the calibrations of different instruments. It does not require knowledge of the cantilever dimensions and composition or its tip height. This standard also allows direct conversion of the photodiode signal to force and, thus, circumvents the requirement for a sensor response (sensitivity) measurement. PMID:17614616

  10. Easy axis alignment of chemically partially ordered FePt nanoparticles

    SciTech Connect

    Kang, Shishou; Jia Zhiyong; Shi, Shifan; Nikles, David E.; Harrell, J.W.

    2005-02-07

    Partially ordered Fe{sub 53}Pt{sub 47} nanoparticles with size around 8 nm were prepared by the simultaneous decomposition of iron pentacarbonyl and platinum acetylacetonate. The high boiling point chemical, hexadecylamine, was used as a solvent, and 1-adamantanecarboxylic acid was used as a stabilizer. X-ray diffraction measurements reveal that as-made FePt particles were partially transformed into the ordered L1{sub 0} phase with some weak superlattice peaks. The room-temperature hysteresis loop and remanence curve suggest a broad distribution of anisotropies in the partially ordered particles. By coating the partially ordered FePt nanoparticles with a polyvinylchloride polymer binder, the particles could be re-dispersed in cyclohexanone. Furthermore, the easy axis of the particles coated with the polyvinylchloride polymer binder could be aligned under an external field. Easy axis alignment was confirmed from both alternating gradient magnetometer and x-ray diffraction measurements.

  11. Easy axis alignment of chemically partially ordered FePt nanoparticles

    NASA Astrophysics Data System (ADS)

    Kang, Shishou; Jia, Zhiyong; Shi, Shifan; Nikles, David E.; Harrell, J. W.

    2005-02-01

    Partially ordered Fe53Pt47 nanoparticles with size around 8nm were prepared by the simultaneous decomposition of iron pentacarbonyl and platinum acetylacetonate. The high boiling point chemical, hexadecylamine, was used as a solvent, and 1-adamantanecarboxylic acid was used as a stabilizer. X-ray diffraction measurements reveal that as-made FePt particles were partially transformed into the ordered L10 phase with some weak superlattice peaks. The room-temperature hysteresis loop and remanence curve suggest a broad distribution of anisotropies in the partially ordered particles. By coating the partially ordered FePt nanoparticles with a polyvinylchloride polymer binder, the particles could be re-dispersed in cyclohexanone. Furthermore, the easy axis of the particles coated with the polyvinylchloride polymer binder could be aligned under an external field. Easy axis alignment was confirmed from both alternating gradient magnetometer and x-ray diffraction measurements.

  12. SCEW: a Microsoft Excel add-in for easy creation of survival curves.

    PubMed

    Khan, Haseeb Ahmad

    2006-07-01

    Survival curves are frequently used for reporting survival or mortality outcomes of experimental pharmacological/toxicological studies and of clinical trials. Microsoft Excel is a simple and widely used tool for creation of numerous types of graphic presentations however it is difficult to create step-wise survival curves in Excel. Considering the familiarity of clinicians and biomedical scientists with Excel, an algorithm survival curves in Excel worksheet (SCEW) has been developed for easy creation of survival curves directly in Excel worksheets. The algorithm has been integrated in the form of Excel add-in for easy installation and usage. The program is based on modification of frequency data for binary break-up using the spreadsheet formula functions whereas a macro subroutine automates the creation of survival curves. The advantages of this program are simple data input, minimal procedural steps and the creation of survival curves in the familiar confines of Excel.

  13. The use of cylindrical lenses in easy experiments for physics education and the magic arts

    NASA Astrophysics Data System (ADS)

    Bednarek, Stanisław; Krysiak, Jerzy

    2011-09-01

    The purpose of this article is to present the properties of cylindrical lenses and provide some examples of their use in easy school physics experiments. Such experiments could be successfully conducted in the context of science education, in fun experiments that teach physics and in science fair projects, or used to entertain an audience by staging tricks, effects or illusions of seemingly impossible or supernatural feats.

  14. Phase states of a 2D easy-plane ferromagnet with strong inclined anisotropy

    SciTech Connect

    Fridman, Yu. A. Klevets, F. N.; Gorelikov, G. A.; Meleshko, A. G.

    2012-12-15

    We investigate the spin states of a 2D film exhibiting easy-axis anisotropy and a strong single-ion inclined anisotropy whose axis forms a certain angle with the normal to the film surface. Such a system may have an angular ferromagnetic phase, a spatially inhomogeneous state, and a quadrupole phase, whose realization depends substantially on the inclined anisotropy and the orientation of the wavevector in the film plane.

  15. 27 CFR 19.956 - Amount of bond.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... of bond. The penal sum of the bond is based on the total quantity of distilled spirits to be produced... increased, and the bond is not in the maximum penal sum, a new or strengthening bond shall be obtained....

  16. Teaching Chemical Bonding: A Resource Book for Senior Chemistry.

    ERIC Educational Resources Information Center

    Lindsay, Margaret

    This document presents an instructional strategy for teaching chemical bonding using parables and music. Games, student interactions, and worksheets are included in the lesson plans. Topics include metallic bonding, covalent bonding including molecular and network structure, and ionic bonding. (JRH)

  17. Pressureless Bonding Using Sputtered Ag Thin Films

    NASA Astrophysics Data System (ADS)

    Oh, Chulmin; Nagao, Shijo; Suganuma, Katsuaki

    2014-12-01

    To improve the performance and reliability of power electronic devices, particularly those built around next-generation wide-bandgap semiconductors such as SiC and GaN, the bonding method used for packaging must change from soldering to solderless technology. Because traditional solders are problematic in the harsh operating conditions expected for emerging high-temperature power devices, we propose a new bonding method in this paper, namely a pressureless, low-temperature bonding process in air, using abnormal grain growth on sputtered Ag thin films to realize extremely high temperature resistance. To investigate the mechanisms of this bonding process, we characterized the microstructural changes in the Ag films over various bonding temperatures and times. We measured the bonding properties of the specimens by a die-shear strength test, as well as by x-ray diffraction measurements of the residual stress in the Ag films to show how the microstructural developments were essential to the bonding technology. Sound bonds with high die strength can be achieved only with abnormal grain growth at optimum bonding temperature and time. Pressureless bonding allows for production of reliable high-temperature power devices for a wide variety of industrial, energy, and environmental applications.

  18. Silver- and gold-mediated nucleobase bonding.

    PubMed

    Acioli, Paulo H; Srinivas, Sudha

    2014-08-01

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

  19. Effect of impression technique on bond strength.

    PubMed

    Su, Jiaping; Hobson, Ross S; McCabe, John F

    2004-01-01

    If the effects of surface preparation (eg, acid etching, laser preparation, crystal growth) are to be investigated on the same tooth from which the bond strength is recorded, a method of surface replication is required that does not affect the subsequent bond. This study investigated the effect of 2 different methods of taking impressions on bond strength. Three groups of 11 mandibular incisors were used. The labial enamel was etched with 37% phosphoric acid for 30 seconds. Group A (control) had no impression taken; in group B (silicone), impressions were taken with silicone impression material before bonding; in group C (polyether), an impression was taken with polyether before bonding. After the impressions were taken, GAC brackets (A Company, San Diego, Calif) were bonded to the labial surfaces of the etched enamel with Transbond XT light-cured composite (3M Unitek, Monrovia, Calif). Teeth with bonded brackets were stored in water at 37 degrees C for 24 hours, and then bond strength was measured on a testing machine. The adhesive remnant index (ARI) was also recorded. The lowest bond strength was found after silicone replication (mean [standard deviation]: 8.6 [1.7] MPa) and the highest in the control group (21.2 [4.0] MPa). There was no significant difference between the control group and the polyether replication group (19.1 [4.7] MPa). The surface detail replications of polyether and silicone were found to be identical. It was concluded that polyether had no significant effect on bond strength and was suitable for surface replication before bonding. Polyether allows replication of the enamel surface without a significant effect on bond strength, and this technique could be used to examine the relationship between enamel preparation techniques and subsequent bond strength between composite and enamel.

  20. Chemical Bonding: The Orthogonal Valence-Bond View

    PubMed Central

    Sax, Alexander F.

    2015-01-01

    Chemical bonding is the stabilization of a molecular system by charge- and spin-reorganization processes in chemical reactions. These processes are said to be local, because the number of atoms involved is very small. With multi-configurational self-consistent field (MCSCF) wave functions, these processes can be calculated, but the local information is hidden by the delocalized molecular orbitals (MO) used to construct the wave functions. The transformation of such wave functions into valence bond (VB) wave functions, which are based on localized orbitals, reveals the hidden information; this transformation is called a VB reading of MCSCF wave functions. The two-electron VB wave functions describing the Lewis electron pair that connects two atoms are frequently called covalent or neutral, suggesting that these wave functions describe an electronic situation where two electrons are never located at the same atom; such electronic situations and the wave functions describing them are called ionic. When the distance between two atoms decreases, however, every covalent VB wave function composed of non-orthogonal atomic orbitals changes its character from neutral to ionic. However, this change in the character of conventional VB wave functions is hidden by its mathematical form. Orthogonal VB wave functions composed of orthonormalized orbitals never change their character. When localized fragment orbitals are used instead of atomic orbitals, one can decide which local information is revealed and which remains hidden. In this paper, we analyze four chemical reactions by transforming the MCSCF wave functions into orthogonal VB wave functions; we show how the reactions are influenced by changing the atoms involved or by changing their local symmetry. Using orthogonal instead of non-orthogonal orbitals is not just a technical issue; it also changes the interpretation, revealing the properties of wave functions that remain otherwise undetected. PMID:25906476

  1. An Easy and Effective Demonstration of Enzyme Stereospecificity and Equilibrium Thermodynamics

    ERIC Educational Resources Information Center

    Herdman, Chelsea; Dickman, Michael

    2011-01-01

    Enzyme stereospecificity and equilibrium thermodynamics can be demonstrated using the coupling of two amino acid derivatives by Thermoase C160. This protease will catalyze peptide bond formation between Z-L-AspOH and L-PheOMe to form the Aspartame precursor Z-L-Asp-L-PheOMe. Reaction completion manifests itself by precipitation of the product. As…

  2. Easy First Steps and Their Implication to the Use of a Mouse-Based and a Script-Based Strategy

    ERIC Educational Resources Information Center

    Yechiam, Eldad; Erev, Ido; Parush, Avi

    2004-01-01

    The present study evaluated the convention to design training environments by giving access to easy strategies first and progressing to more difficult and efficient strategies thereafter. An experiment was conducted focusing on training in a simplified editing task. This task could be performed with an easy (mouse-based) strategy as well as with a…

  3. The Psychosocial Development and Increased Fluency of Users of the SpeechEasyRTM Device: A Multiple Unit Case Study

    ERIC Educational Resources Information Center

    Horgan, David James

    2010-01-01

    This dissertation study explored the efficacy of the SpeechEasy[R] device for individuals who are gainfully employed stutterers and who participated in workplace education learning activities. This study attempted to fill a gap in the literature regarding efficacy of the SpeechEasy[R] device. It employed a qualitative multiple unit case study…

  4. Making the Good Even Better: Feedback from easyCBM Focus Groups, School Year 2009/2010. Technical Report # 1001

    ERIC Educational Resources Information Center

    Alonzo, Julie; Tindal, Gerald; Lai, Cheng-Fei

    2010-01-01

    This technical report provides a summary of feedback from teachers, administrators, and support personnel who used the easyCBM progress monitoring and benchmark assessment system during school year 2009/2010. Data were gathered from semi-structured focus groups conducted during the 2010 easyCBM August Institute at the University of Oregon. Results…

  5. Criterion Validity Evidence for the easyCBM© CCSS Math Measures: Grades 6-8. Technical Report #1402

    ERIC Educational Resources Information Center

    Anderson, Daniel; Rowley, Brock; Alonzo, Julie; Tindal, Gerald

    2012-01-01

    The easyCBM© CCSS Math tests were developed to help inform teachers' instructional decisions by providing relevant information on students' mathematical skills, relative to the Common Core State Standards (CCSS). This technical report describes a study to explore the validity of the easyCBM© CCSS Math tests by evaluating the relation…

  6. Cross-Validation of easyCBM Reading Cut Scores in Oregon: 2009-2010. Technical Report #1108

    ERIC Educational Resources Information Center

    Park, Bitnara Jasmine; Irvin, P. Shawn; Anderson, Daniel; Alonzo, Julie; Tindal, Gerald

    2011-01-01

    This technical report presents results from a cross-validation study designed to identify optimal cut scores when using easyCBM[R] reading tests in Oregon. The cross-validation study analyzes data from the 2009-2010 academic year for easyCBM[R] reading measures. A sample of approximately 2,000 students per grade, randomly split into two groups of…

  7. Diffusion bonding of superplastic aluminum alloys

    SciTech Connect

    Sunwoo, A.J.

    1993-12-01

    Ability to diffusion bond aluminum alloys, in particular superplastic aluminum alloys, will complete the technology-base that is strongly needed to enhance the use of superplastic forming (SPF) technology. Concurrent diffusion bonding (DB)-SPF is considered to be an energy-saving manufacturing process since it simplifies the production of complex components. Moreover, because of increased design flexibility, overall manufacturing cost and component weight are significantly reduced. Diffusion bonding is an attractive manufacturing option for applications where the preservation of the base metal microstructure and, in turn, mechanical properties is imperative in the bond area. The process utilizes either the solid state or transient liquid phase (TLP) bonding to produce a bond with microstructure continuity in the joint. In addition, there is no localized thermal gradient present to induce distortion or to create residual stresses in the component, thereby increasing structural integrity.

  8. Fatigue behavior of adhesively bonded joints

    NASA Technical Reports Server (NTRS)

    Mall, S.

    1983-01-01

    The fatigue damage mechanism of composite to composite adhesively bonded joints was characterized. The mechanics of the possible modes of fatigue damage propagation in these joints when subjected to constant amplitude cyclic mechanical loading were investigated. The possible failure modes in composite bonded joints may be cyclic debonding (i.e., progressive separation of the adhesive), interlaminar damage (delamination), adherend fatigue or a combination of these. Two composite systems - graphite/epoxy adhesively bonded to graphite/epoxy and Kevlar 49/epoxy adhesively bonded to Kevlar 49/epoxy were investigated. Both composite systems consisted of quasi-isotropic lay-ups, i.e., 0 deg/-45 deg/+45 deg/90 degs. The two adhesives, employed in the study were (1) EC 3445 with cure temperature of 250 F for secondary bonding and (2) FM 300 with cure temperature of 350 F for co-cure bonding.

  9. Verification of surface preparation for adhesive bonding

    NASA Technical Reports Server (NTRS)

    Myers, Rodney S.

    1995-01-01

    A survey of solid rocket booster (SRB) production operations identified potential contaminants which might adversely affect bonding operations. Lap shear tests quantified these contaminants' effects on adhesive strength. The most potent contaminants were selected for additional studies on SRB thermal protection system (TPS) bonding processes. Test panels were prepared with predetermined levels of contamination, visually inspected using white and black light, then bonded with three different TPS materials over the unremoved contamination. Bond test data showed that white and black light inspections are adequate inspection methods for TPS bonding operations. Extreme levels of contamination (higher than expected on flight hardware) had an insignificant effect on TPS bond strengths because of the apparent insensitivity of the adhesive system to contamination effects, and the comparatively weak cohesive strength of the TPS materials.

  10. 31 CFR 363.164 - Is a converted savings bond eligible to be converted back into a definitive bond?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... to be converted back into a definitive bond? 363.164 Section 363.164 Money and Finance: Treasury... Bond § 363.164 Is a converted savings bond eligible to be converted back into a definitive bond? Once a definitive savings bond has been converted to a book-entry bond, it may not be converted back into...

  11. 30 CFR 282.40 - Bonds.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false Bonds. 282.40 Section 282.40 Mineral Resources MINERALS MANAGEMENT SERVICE, DEPARTMENT OF THE INTERIOR OFFSHORE OPERATIONS IN THE OUTER CONTINENTAL SHELF FOR MINERALS OTHER THAN OIL, GAS, AND SULPHUR Payments § 282.40 Bonds. (a) Pursuant to the requirements for a bond in § 281.33 of this...

  12. Sensor/ROIC Integration using Oxide Bonding

    SciTech Connect

    Ye, Zhenyu; /Fermilab

    2009-02-01

    We explore the Ziptronix Direct Bond Interconnect (DBI) technology [2] for the integration of sensors and readout integrated circuits (ROICs) for high energy physics. The technology utilizes an oxide bond to form a robust mechanical connection between layers which serves to assist with the formation of metallic interlayer connections. We report on testing results of sample sensors bonded to ROICs and thinned to 100 {micro}m.

  13. Hydrogen-bonded polymer blends

    NASA Astrophysics Data System (ADS)

    Guigley, Kevin Scott

    This thesis discusses three topics in the general area of hydrogen bonded polymer blends. The first pertains to the blending of flame retardant polyphosphazenes. Poly[bis(n-alkyoxy)phosphazenes] blends with poly(butyl methacrylate- co-4-vinyl phenol) (BMAVPh) were initially studied. These results were compared to BMAVPh blends of analogous poly (vinyl n-alkyl ethers) and the phase behavior was similar. Next, poly[bis(carboxylatophenoxy)phosphazene] blends with a structural polyurethane foam were prepared via reactive mixing. The combustion behavior of these foams was analyzed qualitatively, by a horizontal flame test, and quantitatively, by oxygen index (OI) measurements. Both of these tests indicated a modest increase in flame resistance at loadings of 20 wt% and above. In the second topic, equilibrium constants determined from low molecular weight mixtures were used to successfully predict the phase behavior of analogous polymer blends. Due consideration was given to intramolecular screening and functional group accessibility, factors that are a direct consequence of chain connectivity. In the third topic, polymer blends involving an alternating 1:1 copolymer of tetrafluoroethylene (TFE) and a hexafluoroisopropanol modified vinyl ether (HFIPVE) were studied. This copolymer is interesting for both experimental and theoretical studies of the phase behavior of polymer blends because (1) it is amorphous and has a relatively low glass transition temperature (12°C); (2) it has a relatively low solubility parameter (≈7 (cal.cm-3)-0.5); (3) it is soluble in moderately polar solvents, and (4) it contains the hexafluoroisopropanol group that is a strong hydrogen bond donor. Experimental infrared and thermal analysis studies of polymer blends with (co)polymers containing acetoxy, methacrylate and aliphatic ether groups were studied and compared to theoretical predictions of miscibility maps.

  14. DICOR surface treatments for enhanced bonding.

    PubMed

    Bailey, L F; Bennett, R J

    1988-06-01

    Treatments for preparing castable ceramic surfaces for enhanced bonding to specially formulated resin-based cements were examined. An ammonium bifluoride etch combined with gamma-methacryloxypropyl-trimethoxysilane produced shear bond strengths higher than when an ammonium bifluoride treatment was used alone. The method of curing the silane was highly significant in the contribution to the cement/substrate bond strength, with the heat-cure producing the highest values. Long-term water storage tests indicated that the cement bond with etch plus silane-treated castable ceramic surfaces (whether heat or chemically cured silane was used) demonstrated no significant decrease in strength after a one-year period.

  15. Halogen bonding in solution: thermodynamics and applications.

    PubMed

    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.

  16. Effect of Bonding Application Time on Bond Strength of Composite Resin to Glass Ionomer Cement

    PubMed Central

    Panahandeh, Narges; Torabzadeh, Hassan; Ghassemi, Amir; Mahdian, Mina; Akbarzadeh Bagheban, Alireza; Moayyedi, Seddigheh

    2015-01-01

    Objectives: This experimental study evaluated the effect of bonding application time on the microshear bond strength of composite resin to different types of glass ionomer cements (GICs). Materials and Methods: One-hundred and sixty specimens (two conventional and two resin-modified GICs) were prepared and divided into 16 groups. The surface of all specimens was prepared using two different bonding systems (Frog and Stea) at three different times. After setting, the composite resin (Z100) was placed over the GICs. The specimens were then stored in distilled water for 24 hours (37°C) and exposed to microshear stresses at a crosshead speed of 1 mm/min. The results were analyzed using three-way ANOVA and Tukey’s test (P<0.05). Results: In conventional GICs, bond strength was affected by the type of bonding system at different times, and bond strength was significantly higher in the Fuji II group compared to Riva Self Cure group. In the Riva Self Cure group, bond strength was significantly affected by time; whereas, the type of bonding system failed to exert a significant effect on bond strength. There was no significant correlation between the type of bonding system and the two brands of resin-modified GICs. Bond strength was not affected by the type of bonding agent; however, among the two brands of resin-modified GICs, Fuji II LC yielded a significantly stronger bond. Conclusion: It appears that the type of bonding agent does not affect the microshear bond strength, and the bonding application time affects the microshear bond strength in Riva Self Cure GICs. PMID:27507998

  17. Highly compact and easy-to-use optical chip interferometer with picometric performances

    NASA Astrophysics Data System (ADS)

    Merzouk, W. A.; Cagneau, B.; Gardillou, F.; Hilouane, K.; Chassagne, L.

    2016-10-01

    In this paper, we present a compact, inexpensive, and easy-to-use optical chip interferometer based on the telecom integrated waveguide technology. The measurement evaluation is focused on the resolution and the noise level of the sensor. The power spectral density of 100 fm Hz-1/2 @ 10 kHz is reached in static conditions. The same level is obtained with the standard Allan deviation for both short and long term measurements. Dynamic performances are also evaluated with sub-nanometer measurements made with piezoelectric systems. The potential bandwidth of the sensor is very high and is currently only limited by electronics (250 kHz).

  18. Blood oxygen content in microliter samples using an easy-to-build galvanic oxygen cell.

    PubMed

    Grubb, B R; Mills, C D

    1981-02-01

    We have designed a simple, inexpensive, easy-to-build and operate apparatus for measuring blood oxygen content. The galvanic oxygen cell (fuel cell) requires as little as 1 microliter of blood and has a measuring time of 1-3 min. It is well suited for measuring oxygen content in fluids low in oxygen inasmuch as the sensitivity of the instrument is variable. Either air or water (at a known temperature and oxygen tension) can be used for calibration. No significant differences in blood oxygen content measured with our cell or the Van Slyke manometric method were found.

  19. Liquid crystal alignment surface with two easy axes induced by unidirectional rubbing

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Rumiko; Goto, Yusuke; Sato, Susumu

    2003-06-01

    We report the liquid crystal (LC) alignment surface which has two orthogonal easy axes induced by a unidirectional rubbing treatment. When the photoreactive polymer with chalconyl sidechains is irradiated with nonpolarized UV light and subsequently rubbed with a cloth, LCs align parallel and perpendicular to the rubbing direction on the UV irradiated and nonirradiated surfaces, respectively. The polarized UV absorption of the polymer and the sign of the dichroism are measured to explain the alignment mechanism. The micropatterning of the LC alignment is successfully demonstrated through the simple process using a photomask and nonpolarized UV irradiation technique.

  20. An informatics education for improved nursing by introducing an easy data base system.

    PubMed

    Narita, Y; Satou, R; Takahashi, H; Miura, K; Takemoto, Y

    1997-01-01

    We began to explore the subject of nursing information systems nine years ago. Since then, we have advocated a system that is intended to be used by nurses for their own purposes. We have developed an easy database management system (Native Data Base Management System, called NDBS hereafter) that is feasible to operate in the nursing situation. We also have developed an educational training system for information technology, which is appropriate for nursing students as well as for experienced nurses. Both systems have helped to greatly improve nursing services. In fact, nurses have already created several beneficial databases which are tailored to their nursing needs.

  1. Women as easy scapegoats: witchcraft accusations and women as targets in tea plantations of India.

    PubMed

    Chaudhuri, Soma

    2012-10-01

    This article revisits a much-debated question: Why are women popular targets during witch hunts? By using in-depth interviews this article provides an answer. Women are easy targets or scapegoats for two reasons. First, it is widely believed in the community that was studied that witches do, in fact, exist, and the images of witches are always female. Second, tribal women hold lower positions than men in all social, political, and ritual matters, and this contributes to their vulnerability during the hunt for scapegoats. This article also highlights the roles that rumors play during manipulation of witchcraft accusations to gather support for witch hunts.

  2. Women as easy scapegoats: witchcraft accusations and women as targets in tea plantations of India.

    PubMed

    Chaudhuri, Soma

    2012-10-01

    This article revisits a much-debated question: Why are women popular targets during witch hunts? By using in-depth interviews this article provides an answer. Women are easy targets or scapegoats for two reasons. First, it is widely believed in the community that was studied that witches do, in fact, exist, and the images of witches are always female. Second, tribal women hold lower positions than men in all social, political, and ritual matters, and this contributes to their vulnerability during the hunt for scapegoats. This article also highlights the roles that rumors play during manipulation of witchcraft accusations to gather support for witch hunts. PMID:23136181

  3. Heisenberg magnetic chain with single-ion easy-plane anisotropy: Hubbard operators approach

    NASA Astrophysics Data System (ADS)

    Spirin, D. V.; Fridman, Yu. A.

    2003-03-01

    We investigate the gap in excitation spectrum of one-dimensional S=1 ferro- and antiferromagnets with easy-plane single-ion anisotropy. The self-consistent modification of Hubbard operators approach which enables to account single-site term exactly is used. For antiferromagnetic model we found Haldane phase that exists up to point D=4 J (where D is anisotropy parameter, J is exchange coupling), while quadrupolar phase realizes at larger values of anisotropy. Our results specify those of Golinelli et al. (Phys. Rev. B. 45 (1992) 9798), where similar model was studied. Besides the method gives gap value closer to numerical estimations than usual spin-wave theories.

  4. Development of a plasmid vector for easy selection of strong promoters.

    PubMed

    Piñeiro, S A; Sordelli, D O; Centrón, D

    2000-05-01

    A promoter vector pACPR33 for Escherichia coli based on the promotorless ampicillin-resistance gene from pBR322 has been constructed. The promoter of the ampicillin-resistance gene was deleted and replaced by a suitable multiple cloning site. Molecular cloning of promoters into the polylinker resulted in activation of the ampicillin resistance in E. coli. The plasmid contains a functional origin of DNA replication and a tetracycline resistance gene for E. coli, and a chloramphenicol resistance gene for S. aureus. The vector permitted direct detection of promoter activity, especially strong promoters, by easy iodometric determination of beta-lactamase activity in liquid or solid media.

  5. Magnetic soliton transport over topological spin texture in chiral helimagnet with strong easy-plane anisotropy

    SciTech Connect

    Borisov, A. B.; Kishine, Jun-ichiro; Bostrem, I. G.; Ovchinnikov, A. S.

    2009-04-01

    We show the existence of an isolated soliton excitation over the topological ground-state configuration in chiral helimagnet with the Dzyaloshinskii-Moryia exchange and the strong easy-plane anisotropy. The magnetic field perpendicular to the helical axis stabilizes the kink crystal state which plays a role of ''topological protectorate'' for the traveling soliton with a definite handedness. To find new soliton solution, we use the Baecklund transformation technique. It is pointed out that the traveling soliton carries the magnon density and a magnetic soliton transport may be realized.

  6. NASA-easyJet Collaboration on the Human Factors Monitoring Program (HFMP) Study, Second Interim Report

    NASA Technical Reports Server (NTRS)

    Srivastava, Ashok N.; Barton, Phil

    2012-01-01

    This is the second interim report jointly prepared by NASA and easyJet on the work performed under the agreement to collaborate on a study of the factors entailed in flight- and cabin-crew fatigue and decreases in performance associated with fatigue. The objective of this Agreement is to generate reliable procedures that aid in understanding the levels and characteristics of flight- and cabin-crew fatigue factors, both latent and proximate, whose confluence will likely result in unacceptable crew performance. This study entails the analyses of numerical and textual data collected during operational flights.

  7. Quick and easy molecular weight determination with Macintosh computers and public domain image analysis software.

    PubMed

    Seebacher, T; Bade, E G

    1996-10-01

    The program "molecular weights" allows a fast and easy estimation of molecular weights (M(r)), isoelectric point (pI) values and band intensities directly from scanned, polyacrylamide gels, two-dimensional protein patterns and DNA gel images. The image coordinates of M(r) and pI reference standards enable the program to calculate M(r) and pI values in a real time manner for any cursor position. The program requires NIH-Image for Macintosh computers and includes automatic band detection coupled with a densitometric evaluation.

  8. Effect of Pedestal Temperature on Bonding Strength and Deformation Characteristics for 5N Copper Wire Bonding

    NASA Astrophysics Data System (ADS)

    Singh, Gurbinder; Haseeb, A. S. M. A.

    2016-06-01

    In recent years, copper has increasingly been used to replace gold to create wire-bonded interconnections in microelectronics. While engineers and researchers in the semiconductor packaging field are continuously working on this transition from gold to copper wires to reduce costs, the challenge remains in producing robust and reliable joints for semiconductor devices. This research paper investigates the effect of pedestal temperature on bonding strength and deformation for 99.999% purity (5N) copper wire bonding on nickel-palladium-gold (NiPdAu) bond pads. With increasing pedestal temperature, significant thinning of the copper ball bond can be achieved, resulting in higher as-bonded ball shear strengths while producing no pad damage. This can be helpful for low-k devices with thin structures, so as to prevent the use of excessive bond force and ultrasonic energy during copper wire bonding.

  9. Three-Electron Bond Valence-Bond Structures for the Ditetracyanoethylene Dianion.

    PubMed

    Harcourt, Richard D

    2015-05-12

    Using valence-bond structures of the types Ȧ · Ḃ and A∴B or A-̇B to represent diatomic three-electron bonds, two types of valence-bond structures are constructed for the cyclic 6-electron 4-center bonding unit that is present in the ditetracyanoethylene dianion. These latter valence-bond structures, which are obtained by singlet spin-pairing the antibonding electrons of two three-electron bonds, are examples of increased-valence structures. It is shown that increased-valence structures that use the Ȧ · Ḃ three-electron bond structure, which relate easily to their component Lewis structures, should be preferred to those that involve the A∴B or A-̇B three-electron bond structures. STO-6G weights are reported for the two 6-electron 4-center increased-valence structures for the [C2]2(2-) component of the ditetracyanoethylene dianion.

  10. Synergistic and diminutive effects between halogen bond and lithium bond in complexes involving aromatic compounds.

    PubMed

    Liu, Mingxiu; Cai, Mengyang; Li, Qingzhong; Li, Wenzuo; Cheng, Jianbo

    2015-10-01

    Quantum chemical calculations have been performed to study the interplay between halogen bond and lithium bond in the ternary systems FX-C6H5CN-LiF, FLi-C6H5CN-XF, and FLi-C6H5X-NH3 (X = Cl, Br, and I) involving aromatic compounds. This effect was studied in terms of interaction energy, electron density, charge transfer, and orbital interaction. The results showed that both FX-C6H5CN-LiF and FLi-C6H5CN-XF exhibit diminutive effects with the weakening of halogen bond and lithium bond, while FLi-C6H5X-NH3 displays synergistic effects with the strengthening of halogen bond and lithium bond. The nature of halogen bond and lithium bond in the corresponding binary complexes has been unveiled by the quantum theory of atoms in molecules methodology and energy decomposition analysis.

  11. Bonding Durability of Four Adhesive Systems

    PubMed Central

    Seyed Tabai, Elaheh; Mohammadi Basir, Mahshid

    2015-01-01

    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. PMID:27123015

  12. Using beryllium bonds to change halogen bonds from traditional to chlorine-shared to ion-pair bonds.

    PubMed

    Alkorta, Ibon; Elguero, José; Mó, Otilia; Yáñez, Manuel; Del Bene, Janet E

    2015-01-21

    Ab initio MP2/aug'-cc-pVTZ calculations have been carried out to investigate the structures, binding energies, and bonding characteristics of binary complexes HFBe:FCl, R2Be:FCl, and FCl:N-base, and of ternary complexes HFBe:FCl:N-base and R2Be:FCl:N-base for R = H, F, Cl; N-base = NH3, NHCH2, NCH. Dramatic synergistic cooperative effects have been found between the Be···F beryllium bonds and the Cl···N halogen bonds in ternary complexes. The Cl···N traditional halogen bonds and the Be···F beryllium bonds in binary complexes become significantly stronger in ternary complexes, while the F-Cl bond weakens. Charge-transfer from F to the empty p(σ) orbital of Be leads to a bending of the XYBe molecule and a change in the hybridization of Be, which in the limit becomes sp(2). As a function of the intrinsic basicity of the nitrogen base and the intrinsic acidity of the Be derivative, the halogen-bond type evolves from traditional to chlorine-shared to ion-pair bonds. The mechanism by which an ion-pair complex is formed is similar to that involved in the dissociative proton attachment process. EOM-CCSD spin-spin coupling constants (1X)J(Cl-N) across the halogen bond in these complexes also provide evidence of the same evolution of the halogen-bond type.

  13. Metal free carboamination of internal alkynes--an easy access to polysubstituted quinolines.

    PubMed

    Stopka, T; Niggemann, M

    2016-04-28

    A metal free carboamination of unactivated alkynes towards highly substituted quinolines was realized in the presence of a synergistic Brønsted acid catalyst system. Supported by mechanistic probes, the reaction proceeds via a highly reactive vinyl cation in a C-C bond formation--Schmidt reaction sequence. The irreversible extrusion of N2, as a powerful driving force, allows for a general conversion of poorly nucleophilic aliphatic alkynes. PMID:27049140

  14. Water soluble/dispersible and easy removable cationic adhesives and coating for paper recycling

    DOEpatents

    Deng, Yulin; Yan, Zegui

    2005-11-29

    The present invention is an adhesive or coating composition that is dispersible or dissolvable in water, making it useful in as a coating or adhesive in paper intended for recycling. The composition of the present invention is cationically charged thereby binding with the fibers of the paper slurry and thus, resulting in reduced deposition of adhesives on equipment during the recycling process. The presence of the composition of the present invention results in stronger interfiber bonding in products produced from the recycled fibers.

  15. Degree of conversion of simplified contemporary adhesive systems as influenced by extended air-activated or passive solvent volatilization modes.

    PubMed

    Borges, Boniek C D; Souza-Junior, Eduardo Jose; Brandt, William C; Loguercio, Alessandro D; Montes, Marcos A J R; Puppin-Rontani, Regina M; Sinhoreti, Mario Alexandre Coelho

    2012-01-01

    This study evaluated the effect of five methods of solvent volatilization on the degree of conversion (DC) of nine one-bottle adhesive systems using Fourier transform infrared/attenuated total reflectance (FTIR/ATR) analysis. Nine adhesives were tested: Adper Single Bond 2 (SB), Adper Easy One (EO), One Up Bond F Plus (OUP), One Coat Bond SL (OC), XP Bond (XP), Ambar (AM), Natural Bond (NB), GO, and Stae. The adhesive systems were applied to a zinc-selenide pellet and 1) cured without solvent volatilization, 2) left undisturbed for 10 seconds before curing, 3) left undisturbed for 60 seconds before curing, 4) air-dried with an air stream for 10 seconds before curing, and 5) air-dried with an air stream for 60 seconds before curing. FTIR/ATR spectra were obtained, and the DC was calculated by comparing the aliphatic bonds/reference peaks before and after light activation for 10 seconds (FlashLite 1401). The DC means of each material were analyzed by one-way analysis of variance and post hoc Tukey test (p<0.05). The DC of GO and Stae adhesive systems was not affected by the five evaporation conditions. Air-drying for 60 seconds before curing yielded the highest DC for SB, EO, and OC. Extended solvent volatilization time (60 seconds) either with or without air-drying before curing provided the highest DC for AM, NB, XP, and OUP. Thus, the monomer conversion of adhesive systems was material dependent. In general, the 60-second passive or active air-drying modes to volatilize solvents before curing enhanced the degree of conversion for the one-bottle simplified adhesive systems. PMID:22313268

  16. BOND ISSUE--WHAT SHALL WE DO. TECHNIQUES USED IN PROMOTING SCHOOL BOND ELECTIONS.

    ERIC Educational Resources Information Center

    Texas Education Agency, Austin.

    THIS REPORT OUTLINES SUGGESTIONS FOR CONDUCTING SCHOOL BOND CAMPAIGNS. ONE OF THE FIRST STEPS AN ADMINISTRATOR SHOULD TAKE IS TO EVALUATE THE FACTORS IMPORTANT TO THE SELLING OF BONDS--STIMULATE INTEREST IN INVESTMENT DEALERS THEREBY INCREASING COMPETITION FOR BONDS, PREPARE A COMPLETE ACCURATE PROSPECTUS, CIRCULATE THE PROSPECTUS AMONG BOND…

  17. The Effects of Silicone Contamination on Bond Performance of Various Bond Systems

    NASA Technical Reports Server (NTRS)

    Anderson, G. L.; Stanley, S. D.; Young, G. L.; Brown, R. A.; Evans, K. B.; Wurth, L. A.

    2012-01-01

    The sensitivity to silicone contamination of a wide variety of adhesive bond systems is discussed. Generalizations regarding factors that make some bond systems more sensitive to contamination than others are inferred and discussed. The effect of silane adhesion promoting primer on the contamination sensitivity of two epoxy/steel bond systems is also discussed.

  18. 26 CFR 301.7102-1 - Single bond in lieu of multiple bonds.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 26 Internal Revenue 18 2010-04-01 2010-04-01 false Single bond in lieu of multiple bonds. 301.7102-1 Section 301.7102-1 Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY... of multiple bonds. (a) In general. Except as provided in paragraph (b) of this section, a person...

  19. Comprehensive analysis of individual pulp fiber bonds quantifies the mechanisms of fiber bonding in paper

    NASA Astrophysics Data System (ADS)

    Hirn, Ulrich; Schennach, Robert

    2015-05-01

    The process of papermaking requires substantial amounts of energy and wood consumption, which contributes to larger environmental costs. In order to optimize the production of papermaking to suit its many applications in material science and engineering, a quantitative understanding of bonding forces between the individual pulp fibers is of importance. Here we show the first approach to quantify the bonding energies contributed by the individual bonding mechanisms. We calculated the impact of the following mechanisms necessary for paper formation: mechanical interlocking, interdiffusion, capillary bridges, hydrogen bonding, Van der Waals forces, and Coulomb forces on the bonding energy. Experimental results quantify the area in molecular contact necessary for bonding. Atomic force microscopy experiments derive the impact of mechanical interlocking. Capillary bridges also contribute to the bond. A model based on the crystal structure of cellulose leads to values for the chemical bonds. In contrast to general believe which favors hydrogen bonding Van der Waals bonds play the most important role according to our model. Comparison with experimentally derived bond energies support the presented model. This study characterizes bond formation between pulp fibers leading to insight that could be potentially used to optimize the papermaking process, while reducing energy and wood consumption.

  20. Valence-Bond Concepts in Coordination Chemistry and the Nature of Metal-Metal Bonds.

    ERIC Educational Resources Information Center

    Pauling, Linus; Herman, Zelek S.

    1984-01-01

    Discusses the valence-bond method, applying it to some coordination compounds of metals, especially those involving metal-metal bonds. Suggests that transition metals can form as many as nine covalent bonds, permitting valence-theory to be extended to transition metal compounds in a more effective way than has been possible before. (JN)