Robot autonomous navigation

Autonomous vehicle navigation is a very popular research area in the vision and control field. Based on Prof. Dickmanns' philosophy, we implement a navigation algorithm on thc small robot. The robot can rely on its eyes (the camera mounted on thc top of the robot) and control its wheels to walk through the sub-basement hallways of Caltech Moore Lab building. The speed we achieve is robot's mechanical maximum speed 0.5 m/s

Synthesis of Hydrofluorocarbon Ethers and New Amorphous Fluoropolymers with Cyclic Fluorocarbon Ether Units

The main focus of this work is the synthesis of hydrofluorocarbon ethers (HFEs). New synthetic methods and new HFEs were successfully developed. In Chapter 1, new HFEs were synthesized with tetrafluoroethylene (CF2=CF2, TFE) as new engineered fluids. The fluorinated olefins’ addition to alcohols is a more conventional approach to HFEs, and in our group a synthetic method consists of three steps was attempted: a. radical addition of tetrafluoroethylene (TFE) to 2,2-dimethyl-1,3-dioxolane compound; b. hydrolysis of the fluorinated dioxolane compound to make a diol; c. TFE addition to the diol under ionic condition. The following two chapters cover the synthesis of several other HFEs with a strong Lewis acid. Especially the one-step synthesis of sevoflurane starting from hexafluoroisopropanol (HFIP) and difluoromethane (R32) with SbF5 as catalyst gives 95+% yield which is very attractive to industry, meanwhile the catalysts can be recycled for multiple reactions. Several other existing or new HFEs were also synthesized by using the same method. The products were identified with NMR spectroscopy and gas chromatography/mass spectrometry. Another cyclic hydrofluorocarbon ether compound 2,2,5,5-tetrafluoro-2,5-dihydrofuran (M1) was synthesized as a monomer for the development of new amorphous fluoropolymers. M1 has been successfully copolymerized with several perfluoro olefins including CF2=CF2 (TFE), CF3CF=CF2 (HFP), and SF5CF=CF2 (MSF5). And the materials were characterized and analyzed by NMR spectroscopy, attenuated total reflectance-infrared spectroscopy (ATR-IR), thermalgravimetric analysis/mass spectrometry (TGA/MS), scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX), gel permeation chromatography (GPC) and static light scattering (SLS). Along the work of the polymerization of M1, more chemistry has been explored on M1 and several crystal structures were solved, which will be further discussed in Chapter 5 and Chapter 6. In the crystal structures, a variety of short distance contacts of Ag---Ag, Ag---O, H---F, O---F, O-Cl, and F---F, were observed. Two other bissulfonyl chloride compounds were synthesized and in the structure of these two -SO2Cl containing molecules, Cl---O and F---F short contacts were observed and considered as halogen bonding

Close ecological relationship among species facilitated horizontal transfer of retrotransposons

HTT transcripts’ expression change in two BioProjects. (XLSX 24 kb

The role of sustainable development goals, financial knowledge and investment strategies on the organizational profitability: Moderating impact of government support

Recently, sustainable development goals (SDG) and investment strategies and knowledge has become the foremost factors for the high organizational profitability and capture the focus of recent studies and policymakers. Therefore, the current study aims to examine the impact of SDG, investment strategies and financial knowledge on the organizational profitability of manufacturing firms in China. Furthermore, the study examines the role of government support in the interplay between investment plans, financial understanding, and the profitability of organisations. Survey questionnaires and smart-PLS were used to collect data and analyse reliability and correlations. The findings show that SDGs, investment strategies, and financial knowledge all play a substantial role in a company’s profitability.The results also revealed that government support moderates significantly among investment strategies, financial knowledge, and organizational profitability. This study guides the regulators while developing policies regarding SDG and investment strategies with respect to organizational profitability