Dynamics and Fuzzy Control of a Levitated Particle

This paper deals with the control in both horizontal and vertical directions of a nonlinear magnetic spherical particle suspension. A pair of horizontal electromagnets were added to the typical magnetic levitation system in order to handle the horizontal unexpected displacements of the particle. A fuzzy logic controller was designed to bring the particle to the operating location situated on the symmetry axis. Simulations with different initial position conditions of the particle are provided. It was shown that the controller has a good behavior for almost any initial conditions.     

On a sulfurated grignard reagent equivalent to that of 2-chloromethyl-1,3-butadiene. New syntheses of ipsenol (2-methyl-6-methylene-7-octen-4-OL) and of (E)-β-farnesene ((E)-7,11-dimethyl-3-methylene-1,6,10-dodecatriene)

Experiments on the synthesis of (3-methylene-4-chloro)butylphenyl sulfide, which is the precursor of the corresponding Grignard reagent, are described. With two typical electrophiles, namely isovaleraldehyde and geranyl chloride, this reagent provides the title terpenes in two further simple steps (oxidation to sulfoxides and thermolysis).     

Synthesis of functionalized 7-azaindoles via directed ortho-metalations

Functionalization at C-5 of 4-fluoro- and 4-chloro-1-triisopropylsilyl-7-azaindole, 1 and 2, respectively, leads to a variety of new substituted 7-azaindole derivatives. We also describe two approaches to introduce functionality at C-6.     

Controlled assembly of covalent and supramolecular chemical modules: from engineering of complex structures to high-performance chromatography

A biological approach to generating complex behaviors in chemistry is described. It is suggested theoretically that the assembly of modules composed of chemical reactions or molecular structures under appropriate external constraints can lead to features typical of the biological world like autocatalysis, kinetic proofreading, or oriented molecular motion. This approach may account for the primitive steps of molecular evolution and, in addition, it can find useful applications in chemistry such as high-performance chromatography.     

Reaction of 1, 1-Bis(Methylthio)-3-Methyl-1, 3-Butadiene with Lithiated 3-Methyl-2-Butenyl Phenyl Sulfide. A Special Case of Cyclopropane Formation

Abstract

The conjugated ketene dithioacetal 2 is now available by three different procedures¹. This electrophilic isoprene compound has been shown to add smoothly some simple lithio derivatives, but the addition of 3-methyl-2-butenyl-lithium gave a product with total inversion of the starting allylic chain^1a.     

Preparation and Thermal Properties of N-Alkylidene-Ethenesulfenamides

A convenient preparation of N,N-bis(trimethylsilyl)-ethenesulfenamides is describe, together with its fluoride-catalysed reaction with aldehydes or ketones to provide several N-alkylidene-ethenesulfenamides. On mild heating, two of these S-vinylthiooximes can be converted into the corresponding substituted pyrroles.