Metal-metal and metal-sulfur reactive powder mixtures have been previously tested for initiation of reaction via planar, normal-shock loading. In addition to reacting under shock, such powder mixtures may undergo exot...
Metal-metal and metal-sulfur reactive powder mixtures have been previously tested for initiation of reaction via planar, normal-shock loading. In addition to reacting under shock, such powder mixtures may undergo exothermic reaction from other types of mechanical loading. The thick-walled cylinder technique was performed on samples of Ti-B (1:2 molar ratio), Cr-S (1.15:1 molar ratio), and Mn-S (1:1 molar ratio). These experiments were aimed to determine the effect of large shear strains exerted on reactive metal powder mixtures and to establish the relative effectiveness of shear loading in comparison to shock loading for initiating reaction. Recovered samples were analyzed via SEM and XRD to determine the degree of reaction.
We are developing an advanced computer-controlled digital optoelectronic holographic system (DOEHS) with the ability to measure both shape and acoustically induced deformations of the tympanic membrane of several spec...
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Several research groups and projects are aiming to find materials for scaffolding that allow the growing of bone tissue in vitro at laboratory and a guided regeneration of tissues in vivo after implantation [1-2]. The...
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ISBN:
(纸本)9781467362542
Several research groups and projects are aiming to find materials for scaffolding that allow the growing of bone tissue in vitro at laboratory and a guided regeneration of tissues in vivo after implantation [1-2]. The Bioglass? (BG) has shown interesting features for bone tissue engineering, but their mechanical properties are not adequate for direct implantation of dense or porous scaffolds. In this work, we produced porous scaffolds with microparticulate BG, by the slurry dipping method, and then proceeded to coat the samples with chitosan (CHI), to biofunctionalize the surface and improve the mechanical properties. The coatings integrated correctly to the scaffolds (proved by FT-IR) and the mechanical properties were similar to human cancellous bone.
An optimization methodology aiming at energy and cost savings in frost-free refrigerators is advanced. A steady-state simulation model was devised and its predictions for energy consumption were compared with experime...
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Above-band-gap optical excitation produces interdependent structural and electronic responses in a multiferroic BiFeO3 thin film. Time-resolved synchrotron x-ray diffraction shows that photoexcitation can induce a lar...
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Above-band-gap optical excitation produces interdependent structural and electronic responses in a multiferroic BiFeO3 thin film. Time-resolved synchrotron x-ray diffraction shows that photoexcitation can induce a large out-of-plane strain, with magnitudes on the order of half of one percent following pulsed-laser excitation. The strain relaxes with the same nanosecond time dependence as the interband relaxation of excited charge carriers. The magnitude of the strain and its temporal correlation with excited carriers indicate that an electronic mechanism, rather than thermal effects, is responsible for the lattice expansion. The observed strain is consistent with a piezoelectric distortion resulting from partial screening of the depolarization field by charge carriers, an effect linked to the electronic transport of excited carriers. The nonthermal generation of strain via optical pulses promises to extend the manipulation of ferroelectricity in oxide multiferroics to subnanosecond time scales.
Objective: The aim of this in vitro study was to compare the flexural strength and flexural modulus of three formulae self-curing acrylic resin with commercial orthodontic resin. materials and Methods: Three formulae ...
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Objective: The aim of this in vitro study was to compare the flexural strength and flexural modulus of three formulae self-curing acrylic resin with commercial orthodontic resin. materials and Methods: Three formulae of Thai local made resins and a commercial self-curing acrylic resin(Orthocryl) were tested. Thai resin powder was produced by varying amounts of initiator(Asobisisobutyronitrile;AIBN);formula 1, 2, and 3. To investigate the flexural properties, test specimens(3.3 mm x 10 mm x 64 mm) were fabricated, five specimens for each group. Flexural strength and flexural modulus were measured by three-point bending test according to ISO 20795-2: 2010. Statistical analysis was performed using the Kruskal-Wallis test followed by Dunn's multiple comparison test. Result: The Kruskal-Wallis test revealed significant(p < 0.05) differences in flexural strength and flexural modulus among some groups. Orthocryl had the highest flexural strength and formula 1 Thai local made resin had the highest flexural modulus according to Dunn's test(p< 0.05). Conclusion: From the results of this study, the amount of initiator in Polymethylmethacrylate(PMMA) beads synthesis had no effect on flexural strength, but it was consistent with flexural modulus of Thai local made resin. However, the molecular weight of each group of Thai local made resin powder needs to be investigated to find the optimal molecular weight distribution in a subsequent study.
Multi-hole defect (MHD) photonic crystal cavities functionalized with in situ synthesized DNA bioreceptors are demonstrated for biosensing applications. By significantly increasing light interaction with target biomol...
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This paper discusses a new class of PEMs that are based on a PE-g-s-PAES graft copolymer containing several sulfonated poly(arylene ethersulfone) side chains. The unique combination of hydrophobicity, semi-crystallini...
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