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Numerous strategies to improve the fiber-matrix interaction in natural fiber composites (NFCs) and wood polymer composites (WPCs) have been proposed and investigated. We have reviewed literature on polyolefin-based NFCs and WPCs to get an overview of the current state of the art of compatibilization methods. Those are classified in two categories here, namely fiber-based strategies and matrix-based strategies. Although this issue has been covered by several reviews before, as yet no work exists that is focused on polyolefin-based NFCs and WPCs. Furthermore, a ranking of the compatibilization methods based on their effects on material properties such as tensile/flexural strength and modulus, impact strength and water absorption, allows for an assessment of the efficiency of the various methods. As to the fiber-based strategies, silanes, maleated polyolefins (MA-POs), mercerization and acetylation are most thoroughly investigated. Silanes are most effective judged by achievable material property improvements, allowing for increases in tensile and flexural strength of more than 100%. Among the matrix-based strategies, MA-POs and isocyanates are most prominent in the literature. The first class enables the more significant material improvements, with reported increases of tensile and flexural strength of 132% and 85%, respectively. While strengths can be enhanced by many compatibilization methods, moduli, and impact strength (notched in particular) are in most cases improved to a lesser degree or even reduced. Especially, the last point calls for further attention, because impact strength is still a weak point of NFCs and WPCs.

Here, we present a comparative structure-function study of a nematode and a plant core α1,3-fucosyltransferase based on deletion and point mutations of the coding regions of Caenorhabditis elegans FUT-1 and Arabidopsis thaliana FucTA (FUT11). In particular, our results reveal a novel "first cluster motif" shared by both core and Lewis-type α1,3-fucosyltransferases of the GT10 family. To evaluate the role of the conserved serine within this motif, this residue was replaced with alanine in FucTA (S218) and FUT-1 (S243). The S218A replacement completely abolished the enzyme activity of FucTA, while the S243A mutant of FUT-1 retained 20% of the "wild-type" activity. Based on the results of homology modeling of FucTA, other residues potentially involved in the donor substrate binding were examined, and mutations of N219 and R226 dramatically affected enzymatic activity. Finally, as both FucTA and FUT-1 were shown to be N-glycosylated, we examined the putative N-glycosylation sites. While alanine replacements at single potential N-glycosylation sites of FucTA resulted in a loss of up to 80% of the activity, a triple glycosylation site mutant still retained 5%, as compared to the control. In summary, our data indicate similar trends in structure-function relationships of distantly related enzymes which perform similar biochemical reactions and form the basis for future work aimed at understanding the structure of α1,3-fucosyltransferases in general.

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Service and high level load tests on a typical single span stone arch bridge in the south of Ireland and an associated set of three-dimensional nonlinear numerical analyses are discussed in this paper. The three-dimensional finite element models, which were generated using a commercially available finite element package, include the arch fill and a frictionless contact interface between this fill and the spandrel walls modelled with a nonlinear smeared crack material model. While this modelling strategy has been previously corroborated for service load levels, the results of the numerical model (which are compared with results from the experimental tests) also demonstrate the suitability of this modelling strategy at higher load levels. Finally, the suitability of three-dimensional solid models in the context of stone arch bridge assessment is discussed