Flexible support structure design for optical mirror

In order to realize the high-precision assembly of the mirror of the aeronautical optical system, a semi-kinematic flexible support structure applied to the airborne field was designed. This paper studies the support principle and assembly method of flexible support of mirror. Firstly, according to the kinematic theory of space mechanism, the spatial degrees of freedom of the mirror were theoretically analyzed. Then, in view of the difficulties encountered in the assembly and application of the mirror, a flexible support structure was designed. Then, the design results were verified by means of finite element analysis. Finally, the processing and assembly of a flexible support structure of the mirror was completed, and the relevant experimental tests were carried out. The experimental results show that the accuracy of the mirror after assembly with flexible support structure is better than λ/50 (λ = 632.8 nm), and the mass is less than 2 kg. The model fundamental frequency modal of the whole assembly is 645 Hz, which is higher than the design requirement. All simulation and test results show that the flexible support structure works well, meets the requirements of aviation optical system, and has the advantages of simple assembly, high precision, stability and reliability.

Photocatalytic materials immobilized on recycled supports and their role in the degradation of water contaminants: A timely review

Global concern about environmental pollution has increased in recent times due to the cumulative harmful impact on the human health occasioned by the diverse toxic substances released into the environment. Water reduced availability for human consumption and its pollution have been paid so much attention due to their relevance in agricultural and industrial activities. In this context, the advanced oxidation processes for removing contaminants from water, more specifically photocatalytic processes, have displayed their usefulness due to features such as easy application, low-cost, harmless effects and sustainable decontamination efficiency. This timely review is centered on worldwide studies, where efforts aimed at employing recycled materials as supports for purification applications such as the removal of different contaminants (dyes, pharmaceutical contaminants, and heavy metals) dissolved in aqueous environments have been reported. Materials like polyethylene terephthalic (PET), polystyrene (PS), disposal textile fabrics, newspapers, aluminum soda cans, rubber, waste electronic and electric components and used batteries have been employed either as supports for immobilizing catalysts or as photocatalysts. The present work offers a discussion of the ways through which photocatalytic composites have been immobilized or produced, employed characterization techniques, removal efficiencies achieved during photocatalytic degradation and possible degradation mechanism of pollutants; not only the highlights of all these studies are discussed, but also paths for future research works that could help improve the reported results are suggested. These new practical tools stand as novel sustainable strategies for the removal of emerging contaminants reusing waste flexible materials.