Objectives: (1) Test the sealing capacity and tensile strength of various adhesive systems: Scotch Bond 1 (Single Bond in USA)(SB1)+Z100, Syntac Sprint (SYN)+Tetric Ceram, Prime and Bond 2.1 (PB21)+TPH Spectrum, F2000 (Adhesive+Compomer) (F2000) and Optibond Solo (OPT)+Prodigy, to perfused teeth (30 cm distilled H2O), in select areas. (2) Determine the relationship between sealing ability and size of adhesive area (BA) with tensile strength (TS).
Methods: Segments of human third molars (n=67) sealed with amalgam on their coronal side were connected to a perfusion system (30 cm distilled H2O), to measure the basal permeability. Access cavities were drilled through the amalgam to expose dentin (area range: 8.7-20.8 mm2) and measure the permeability of that area. Cavities were sealed with one of the test materials and permeability measured prior to tensile testing. The percentage of decrease in permeability (PPD) that occurred with the different combinations of materials was also measured. RESULTS. TENSILE STRENGTH: there were no statistically significant differences among groups. PERMEABILITY: ANOVA showed that there were statistically significant differences in the mean % decrease in permeability (PPD) among groups (p=0.018). Student-Newman-Keuls test (p<0.05) detected that the mean PPD of F2000 ranked statistically higher than that of SB1. Relationship among variables: a linear correlation was found defined by the formula TS=7.47+0.008 x PPD-0.23 x BA, with a significance of the model p=0.0097.
Significance: None of the materials studied reduced permeability up to 100%. They all produced low tensile bond strengths (maximum mean value of groups: 5.51 MPa (OPT)).
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http://dx.doi.org/10.1016/s0109-5641(00)00057-9 | DOI Listing |
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Center for Applied Climate Sciences, University of Southern Queensland, Toowoomba, Australia.
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January 2025
Beijing Solidwel Intelligent Technology Co., Ltd., BeiJing, 100000, China.
Based on the Johnson-Cook constitutive model and modified Coulomb's law, the study investigates the impact of various process parameters on the weld temperature field in high-strength 5052 aluminum alloy friction stir welding (FSW) for aerospace applications. Utilizing a thermo-mechanical model, the significance of rotational speed, welding speed, and indentation on the peak weld temperature is examined through Taguchi's orthogonal experimental design. S/N ratio and ANOVA results show that the rotational speed has the most significant effect on the peak temperature of the weld, followed by the amount of indentation, and the welding speed has the smallest effect, the optimal combination of welding process parameters is determined as follows:the rotational speed is 1000 rpm, the amount of indentation is 0.
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January 2025
Key Laboratory of Geological Safety of Coastal Urban Underground Space, MNR, Qingdao, 266101, China.
To offer guidance for using Brazilian tensile strength (BTS) to estimate UCS of heterogeneous rocks, this study uses sandstone (fine or coarse grain) and gneiss (0°, 45°, 90° inclined anisotropy) to investigate the influence of grain size or anisotropy on the correlations of UCS-BTS. According to the regression analysis, there is no significant equation of UCS-BTS for rocks with vertical anisotropy. The grain size variation or multidirectional anisotropy can result in a decrease in the determination coefficient value of correlations.
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January 2025
Department of Materials Science, Graduate School of Engineering, Chiba University, 1-33, Yayoi-cho, Inage-ku, Chiba, 263-8522, Japan.
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Faculty of Forestry, Isparta university of Applied Science, Isparta Merkez/Isparta, Çünür, 32260, Turkey.
Due to the scarcity of wood in some countries, it is necessary to replace it with other raw materials and at the same time use the waste material. The aim of this research is to use poppy waste straw for the efficient conversion of possible lignocellulosic materials - pulps and particleboards. Their suitability for the production of composites is assessed on the basis of selected physical or mechanical properties.
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