Enantioselective synthesis of (+)-petromyroxol, enabled by rhodium-catalyzed denitrogenation and rearrangement of a 1-sulfonyl-1,2,3-triazole

Petromyroxol is a non-racemic mixture of enantiomeric oxylipids isolated from water conditioned with larval sea lamprey. The (+)-antipode exhibits interesting biological properties but only 1 mg was isolated from >100000 L of water. Recently, transition metal-catalyzed denitrogenation of 1-sulfonyl-1,2,3-triazoles has emerged as a powerful strategy for the synthesis of value-added products, including efficient diastereocontrolled construction of tetrahydrofurans. This methodology enabled the rapid development of the first synthesis of (+)-petromyroxol in 9 steps and 20% overall yield from a readily accessible starting material

Case-Building Behavior, Persistence, and Emergence Success of \u3ci\u3ePycnopsyche Guttifer\u3c/i\u3e (Walker) (Trichoptera: Limnephilidae) in Laboratory and \u3ci\u3ein situ\u3c/i\u3e Environments: Potential Trade-Offs of Material Preference

When removed from their cases in a non-flow laboratory environment, 5th instar Pycnopsyche guttifer (Walker) larvae were always successful in constructing a new case within 24 h when woody debris was present as a material choice. Most were successful within 1 h. Larvae were never successful at case building in the absence of wood in a non-flow environment. These laboratory-constructed ‘emergency cases’ were flimsy, lacking in shape, and larger than field cases. Laboratory case size, shape, and material preference remained constant after repeated daily evacuations over a series of 10 days. Larvae could be induced to construct a case composed of mineral particles only in the absence of wood and when placed in a laboratory stream with simulated flow conditions, or in situ in a natural stream. The emergence success of P. guttifer specimens induced to build these mineral cases, however, was significantly higher than that of larvae remaining in their field cases or of larvae that built wood cases. This result is likely due to a fungal infection that affected only larvae in wood cases. Our results demonstrate a scenario where a clearly non-preferred case construction material appears to increase survival

Potential application of LDPE plastic waste into tiles

Plastic has interesting characteristics which makes it the most used material in the world. However, plastic is known to be a non-biodegradable material which unable to naturally decompost in soil and thus contribute to environmental issue. As alternative, plastic waste has been recycled to produce quality and sustainable construction materials as the source is abundant. Thus, this study is carried out to utilize plastic waste particularly low density polyethylene (LDPE) and with sand in manufacturing tiles in two different sand and plastic waste ratios of 2:1 and 2:2. The tiles manufactured were further analyzed for their water absorption and compressive strength. It was found that the tiles made of mixture ratio of 2:2 have higher compressive strength and lower weight compared to that of 2:1 ratio. The average weight of tiles for 2:1 ratio was 891.59 g, while ratio 2:2 produced tiles with weight of 1319.5 g. Tiles manufactured from the plastic waste also showed better water absorption and compressive strength compared to normal cement tiles

On Mechanically Coupled Tapered Laminates with Balanced Plain Weave and Non-Crimp Fabrics

This article presents definitive stacking sequence listings for tapered, warp-free balanced plain weave and non-crimp fabric (NCF) laminate designs with and without Extension-Shearing and/or Bending-Twisting coupling behaviour.<p></p> With few exceptions, tapered designs for uni-directional (UD) material are currently certified only for balanced and symmetric laminate construction, despite the severe design constraint that 1 angle-ply termination therefore requires a further 3 angle-ply terminations. By contrast, an extensive design space has recently been discovered for tapered UD laminates with single ply terminations, including single angle-ply terminations, representing unconventional laminate designs with unbalanced and/or non-symmetric stacking sequences. Such designs give rise to Bending-Twisting and/or Extension-Shearing coupling:<p></p> Extension-Shearing coupling, which arises in unbalanced construction, can be exploited to produce bending-twisting deformation in aircraft wing-box structures when top and bottom skins have identical bias fibre alignment, but equally, this can be eliminated with opposing bias fibre alignment; Bending-Twisting coupling, which is generally present in symmetric laminate construction, results in weaker compression buckling strength compared to the equivalent fully uncoupled laminate (with matching stiffness properties), but with potentially stronger shear buckling strength.<p></p> Single ply terminations applied to NCF or balanced plain weave materials are equivalent to two adjacent ply terminations in traditional UD materials, and therefore introduce a constraint that may reduce the design space substantially, particularly in ‘thin laminate’ designs. However, this can be overcome by adopting ‘thin-ply’ or ‘spread-tow’ technology, which will allow an exponential increase in tailoring opportunities by bringing design flexibilities, found only in traditionally thick laminate construction, into the thin laminate domain.<p></p> Thin-ply technology will, for instance, offer the prospect of a repeating 8-ply NCF laminate, with a similar thickness to that of a single ply of traditional UD material. This design also follows the repeating bi-angle philosophy, possessing Extension-Shearing and Bending-Twisting coupling, but now with immunity to thermal warping distortions, which are eliminated in bi-angle laminates only when the number (r) of repeats becomes very large