232 research outputs found
Study of impact on helicopter blade
This article presents a study of damage in structures that are similar to helicopter blade sections, subjected to an impact. These complex composite structures were impacted by a steel ball of 125 g at impact speed ranging from 30 to 130 m/s. This led to properly highlight the kinematics of the impact and to define the sequence of the damageâs mechanisms. An explicit FE model is also presented. The damage modelling of the roving is performed through a scale change. It allows a good representation of observed experimental behaviour. As the mesh density is low, it can be used for the modelling of a real structure
Lanthanides: Applications in Cancer Diagnosis and Therapy
Lanthanide complexes are of increasing importance in cancer diagnosis and therapy, owing to the versatile chemical and magnetic properties of the lanthanide-ion 4f electronic configuration. Following the first implementation of gadolinium(III)-based contrast agents in magnetic resonance imaging in the 1980s, lanthanide-based small molecules and nanomaterials have been investigated as cytotoxic agents and inhibitors, in photodynamic therapy, radiation therapy, drug/gene delivery, biosensing, and bioimaging. As the potential utility of lanthanides in these areas continues to increase, this timely review of current applications will be useful to medicinal chemists and other investigators interested in the latest developments and trends in this emerging field
Intraligand charge transfer enables visible-light-mediated nickel-catalyzed cross-coupling reactions
We demonstrate that several visible-light mediated carbonâheteroatom cross-couplings can be carried out using a photoactive NiII precatalyst that forms in situ from a nickel salt and a bipyridine ligand decorated with two carbazole groups (Ni(Czbpy)Cl2). The activation of this precatalyst towards cross-couplings follows a hitherto undisclosed mechanism that is different from previously reported light-responsive nickel complexes that were reported to undergo metal-to-ligand charge transfer. Theoretic and spectroscopic investigations revealed that irradiation of Ni(Czbpy)Cl2 with visible-light causes an initial intraligand charge transfer event that triggers productive catalysis. Ligand polymerization affords a porous, recyclable organic polymer for heterogeneous nickel catalysis of cross-couplings. The heterogeneous catalyst shows stable performance in a packed-bed flow reactor during a week of continuous operation
Enzymatic processing of protein-based fibers
Wool and silk are major protein fiber materials used by the textile industry. Fiber protein structure-function relationships are briefly described here, and the major enzymatic processing routes for textiles and other novel applications are deeply reviewed. Fiber biomodification is described here with various classes of enzymes such as protease, transglutaminase, tyrosinase, and laccase. It is expected that the reader will get a perspective on the research done as a basis for new applications in other areas such as cosmetics and pharma.This work was financially supported by the National Natural Science Foundation of China (21274055,51373071, 31201134 and 31470509), the Program for New Century Excellent Talents in University (NCET-12-0883), the Program for Changjiang Scholars and Innovative Research Team in University (IRT1135), the Jiangsu Provincial Natural Science Foundation of China (BK2012112), and the Fundamental Research Funds for the Central Universities (JUSRP51312B)
Intraligand Charge Transfer Enables Visible Light Mediated Nickel Catalyzed Cross Coupling Reactions
We demonstrate that several visible light mediated carbon heteroatom cross coupling reactions can be carriedout using a photoactive Ni II precatalyst that forms in situ from a nickel salt and a bipyridine ligand decorated with two carbazole groups Ni Czbpy Cl2 . The activation of this precatalyst towards cross coupling reactions follows a hitherto undisclosed mechanism that is different from previously reported light responsive nickel complexes that undergo metal to ligand charge transfer. Theoretical and spectroscopic investigations revealed that irradiation of Ni Czbpy Cl2 with visible light causes an initial intraligand charge transfer event that triggers productive catalysis. Ligand polymerization affords a porous, recyclable organic polymer for heterogeneous nickel catalysis of cross coupling reactions. The heterogeneous catalyst shows stable performance in a packed bed flow reactor during a week of continuous operatio
Critical Theorising from Studies of Undergraduate Mathematics Teaching for Studentsâ Meaning Making in Mathematics
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