Quality Changes in Hermetically Stored Corn Caused by Fungi and Sitophilus Zeamais

Hermetic storage has been shown to be effective in controlling insect pests and maintaining grain quality of dry grains at 13% moisture and below. However, the feasibility and use of hermetic storage for grains at intermediate mid-moisture levels under the influence of the sub-Saharan African weather conditions is relatively unknown. Hermetic storage experiments were conducted on grade 1 6297 and 6333 VT RIB hybrid corn under controlled temperature conditions at 10 degrees centigrade and 25 degrees centigrade at target approximate moisture content levels of 11, 15, 18 and 21% wet basis for a total storage period of 6 months. Corn quality was evaluated by using mold counts, aflatoxin levels, free fatty acids, germination, gas composition, and nutritional composition. The results showed that hermetic storage is effective at suppressing mold growth, minimizing aflatoxins levels and maintaining the nutritional content of corn stored at 11 and 15% MC w.b. Non-hermetic storage was better at preserving germination. Mold count, aflatoxin, free fatty acids generally increased with temperature, moisture content and storage time

Nanomaterials in 2 dimensions for flexible solar cell applications a review

This review presents the progress, challenges and prospects of ultrathin flexible photovoltaic devices based on 2 dimensional 2D nanomaterials. These devices have shown very high performance in bending stabilities for up to 90 of their power conversion efficiencies PCEs after multiple bending deformations. They are thin film PVs with lightweight and mechanically robust structures that allow use in the continual advancing solar cell applications. In this paper, comprehensive assessments of 2D nanomaterials, their syntheses methods, performance, degradation, mechanical and opto electronic characterization in flexible photovoltaic PV cells are highlighted. Semi conductor materials such as conjugated donor and acceptor polymers, small donor acceptor molecules and organometal halide perovskites for use as active layers in such flexible solar cell structures are reviewed. The challenges and prospects associated with the adoption of 2D nanomaterials in flexible solar cells are presented. The review highlights the need to transition laboratory results on 2D nanomaterials based flexible solar cells into scale up and commercialized products despite the existing and also opens research areas for researchers to explore and achieve robust and high efficient solar device

Measurement of contractile forces generated by individual fibroblasts on self-standing fiber scaffolds

# The Author(s) 2010. This article is published with open access at Springerlink.com Abstract Contractility of cells in wound site is important to understand pathological wound healing and develop therapeutic strategies. In particular, contractile force generated by cells is a basic element for designing artificial three-dimensional cell culture scaffolds. Direct assessment of deformation of three-dimensional structured materials has been used to calculate contractile forces by averaging total forces with respect to the cell population number. However, macroscopic methods have offered only lower bounds of contractility due to experimental assumptions and the large variance of the spatial and temporal cell response. In the present study, cell contractility was examined microscopically in order to measure contractile forces generated by individual cells on self-standing fiber scaffolds that were fabricated via femtosecond laser-induced two-photon polymerization. Experimental assumptions and calculation errors that arose in previous studies of macroscopic and microscopic contractile force measurements could be reduced by adopting a columnar buckling model on individual, standing fiber scaffolds. Via quantifying eccentric critical loads for the buckling of fibers with various diameters, contractile forces of single cells were calculated in the range between 30–116 nN. In the present study, a force magnitude of approximately 200 nN is suggested as upper bound of the contractile force exerted by single cells. In addition, contractile forces by multiple cells on a single fiber were calculated in the range between 241–709 nN