Synthesis of 2,2,4,4-Tetramethyl-N,N′-bis(2,6-dimethylphenyl)cyclobutane-1,3-diimine, a Unique Compound from Arundo donax, and Its Analogues to Test Their Antifeedant Activity Against the Boll Weevil, Anthonomus grandis
2,2,4,4-Tetramethyl-N,N′-bis(2,6-dimethylphenyl) cyclobutane-1,3-diimine (1), which was isolated from the Thai plant Arundo donax as an antifeedant against the boll weevil (Anthonomus grandis), and its analogues (9-13) were synthesized and shown to possess no remarkable antifeedant activity of practical interest.
Boll weevil antifeedants from Arundo donax.
Abstract Triacontanol, tricin and tetramethyl- N,N -bis(2,6-dimethylphenyl)cyclobutane-1,3-diimine, newly reported from Arundo donax , showed significant antifeedant activity against the boll weevil, Anthonomus grandis . A common mixture of phytosterols was also obtained from the aerial parts of the plant, but none showed any antifeedant activity.
Evaluation of buckling load and dynamic performance of steel shear wall retrofitted with strips made of shape memory alloy
One of the most imperfections of the steel shear wall is out of plane displacements that cause severe damage in both structural and non-structural elements. In this paper, the effects of shape-memory alloys on steel shear walls are investigated. First, a numerical analysis using the finite element method in ABAQUS software has been carried out according to an experimental test. The results of the numerical analysis have been verified with experimental results. Next, shape-memory alloy fibers have been added vertically and horizontally to various parts of the steel shear wall. The results show that retrofitting with the shape-memory alloy reduces the out-of-plane displacement of the steel shear wall under both cyclic and seismic loadings. Besides, the buckling load in the steel shear wall increases when it is retrofitted with the shape-memory alloy. Also, the total out-of-plane movement (accumulated absolute displacements) of the steel shear wall and non-structural damage are controlled by the characteristic of a shape-memory alloy material called “super-elastic”.