Twelve types of bulk and intense sweeteners were investigated. The relative sweetness was measured by 2-alternative forced choice method with 5% sucrose solution and the results were validated using descriptive analysis. The relative sweetness of the novel sweeteners such as tagatose, erythritol, stevia, and rebaudioside A 97 were shown to be 0.85, 0.63, 64.1, and 227, respectively. Maltitol and tagatose were shown to elicit very similar sensory characteristics to that of sucrose.”
“We report the design of a two-dimensional gradient-index phononic crystal (GRIN PC) structure, which selleck chemicals effectively demonstrates the “”acoustic mirage”"
effect on the wavelength scale. Using the GRIN PC, the propagating direction of acoustic waves can be continuously bent along an arc-shaped trajectory by gradually tuning
the filling ratio of PCs. We investigate the acoustic mirage effect through both plane wave expansion and finite-difference time-domain methods. By controlling the incident angle or operating frequency, the arc-shaped trajectory of acoustic wave propagation can be dynamically adjusted. The GRIN PC structure is composed of steel cylinders, positioned in a square lattice, and immersed in an epoxy. It can be fabricated through a simple process and seamlessly integrated with existing acoustic devices. In addition, we establish that
such an acoustic effect can be used in the design of tunable acoustic CDK inhibitor waveguides, which could find applications in acoustic switching, filtering, and biosensing.”
“Side-chain free aromatic polyimides this website are expected to possess extraordinary mechanical properties and stability because of strong primary and secondary bonding forces. However, their low solubility makes it difficult to characterize, process, and obtain high molecular weight polymers. We have prepared highly stable thin films of side-chain free aromatic polyimides from soluble Diels-Alder (DA) precursors. Heating the films of the precursors above 215 degrees C induced retro-DA reaction, which converted the precursors to the fully aromatic polyimides. The solid-state retro-DA reactions were monitored by attenuated total reflection Fourier transformed infrared (ATR-FTIR) and UV-Vis spectrometry. A critical issue for utilizing precursor chemistry in polymer synthesis is that it may result in porous and/or deformed materials. In this work, profilometry and atomic force microscope (AFM) were applied to study the surface and volume change. Our results showed that smooth and pin-hole free films were obtained after the thermal treatment, while the Volume decreased with a percentage close to the weight loss caused by the retro-DA reaction. (C) 2009 Wiley Periodicals, Inc.