Antimicrobial soy protein isolate‐based films: physical characterisation,active agent retention and antifungal properties against Penicillium italicum

Soy protein isolates (SPI) films were evaluated as carriers of citral and limonene, and their physical and antifungal properties were evaluated. The presence of antimicrobials in SPI films resulted in changes on colour without affecting the transparency. Films with citral added were more extensible; however, a reduction in tensile strength and elastic modulus was observed in films with limonene added. Aroma compounds addition in films induced a slight increase in water vapour properties in relation to discontinuity of network proteins evidenced by SEM. Besides, FTIR spectra evidenced a partial alteration of SPI secondary structure. Citral was less retained than limonene. The increase in limonene release with high relative humidity was explained by increase in protein chain mobility. SPI films enriched with limonene exhibited strong antifungal activity against the postharvest decay pathogen Penicillium italicum under storage conditions.     

Diffusion coefficients of additives in polymers. I. Correlation with geometric parameters

Diffusion coefficients of a broad range of molecules with molecular weight ranging from 100 to 800 g/mol have been measured in polypropylene, by solid/solid contact methods (without liquid contact), at 40°C. The behaviors of the different molecules are compared to those of linear alkanes. The diffusion coefficients are correlated to parameters describing size, shape, and flexibility of the molecules. The concept of weighted fractionated volume is introduced using molecular modeling. It enables the classification of the molecules according to modes of molecule displacement (crawling, jumps, or dual mode). © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2422–2433, 2001     

A polyamidoamine dendrimer as a selective colorimetric and ratiometric fluorescent sensor for Li+ cations in alkali media

In a DMF + NaOH medium, a polyamidoamine dendrimer having sixteen 1,8-naphthalimide fragments in its periphery, formed a complex only with Li⁺ ions, detected by a colour change from red to yellow and by a significant increase in fluorescence intensity. The dendrimer can be used as a selective sensor for Li⁺ ions in the presence of other alkali ions such as Na⁺ or K⁺.     

A constructive fixed point theorem for min-max functions

Min-max functions, F :R n R n , arise in modelling the dynamic behaviour of discrete event systems. They form a dense subset of those functions which are homogeneous, F i (x 1 + h, .. . , x n + h) = Fi(x 1 , . . . , x n ) + h, monotonic , x y F(x) F(y), and nonexpansive in the l infinity norm-so-called topical functions-which have appeared recently in the work of several authors. Our main result characterizes those min-max functions which have a (generalized) fixed point, where Fi(x) = x i + h for some h R. We deduce several earlier fixed point results. The proof is inspired by Howard's policy improvement scheme in optimal control and yields an algorithm for finding a fixed point, which appears efficient in an important special case. An extended introduction sets the context for this paper in recent work on the dynamics of topical functions.     

Modeling the short-circuit current density of polymer solar cells based on P3HT:PCBM blend

We have investigated the short-circuit current density of organic solar cells based on poly (3-hexylthiophene)(P3HT)/6,6-phenyl C61-butyric acid methyl ester (PCBM) blend. In order to model charge collection efficiencies with respect to short circuit density in such blends, a full optical modeling of the cell is performed. From the distribution of the electromagnetic field, we compute the rate of exciton generation. This exciton generation rate is used as input in the transport equations of holes and electrons. Charge densities at steady state are obtained as solutions are used for computing short-circuit current densities generated in the cell. The dependence of short-circuit current densities versus the thickness of the blend is analyzed and compared with our experimental data and with data extracted from the literature.     

Did the Stern Review underestimate US and global climate damages?

The Stern Review received widespread attention for its innovative approach to the economics of climate change when it appeared in 2006, and generated controversies that have continued to this day. One key controversy concerns the magnitude of the expected impacts of climate change. Stern's estimates, based on results from the PAGE2002 model, sounded substantially greater than those produced by many other models, leading several critics to suggest that Stern had inflated his damage figures.     

A Fitted L-Multi-Point Flux Approximation Method for Pricing Options

Computational Economics - In this paper, we introduce a special kind of finite volume method called Multi-Point Flux Approximation method (MPFA) to price European and American options in two...     

M9住宅一期

建筑师:Sid Lee建筑事务所+Aedifica项目地点:加拿大,魁北克建筑面积:789M.C.摄影:Stephane Brugger Architects:Sid Lee Architecture+Aedifica Location:Montreal,Quebec,Canada Gross Floor Area:789M.C.Photos:Stéphane Brügger     

Diameter-dependent electromechanical properties of GaN nanowires

The diameter-dependent Young's modulus, E, and quality factor, Q, of GaN nanowires were measured using electromechanical resonance analysis in a transmission electron microscope. E is close to the theoretical bulk value ( approximately 300 GPa) for a large diameter nanowire (d=84 nm) but is significantly smaller for smaller diameters. At room temperature, Q is as high as 2,800 for d=84 nm, significantly greater than what is obtained from micromachined Si resonators of comparable surface-to-volume ratio. This implies significant advantages of smooth-surfaced GaN nanowire resonators for nanoelectromechanical system (NEMS) applications. Two closely spaced resonances are observed and attributed to the low-symmetry triangular cross section of the nanowires.