We developed poly(dimethyl)silane-supported Pd catalysts that are readily prepared from Pd(OAc) 2 ,p oly(dimethyl)silane, and Al 2 O 3 .T he immobilization was achieved for the first time with as upport that does not contain benzene rings. The Pd catalyst thus prepared was found to have higher hydrogenation activity than Pd/C. Furthermore,t he catalystw as used in continuous-flow hydrogenation with various substrates, including simple liquid substrates (neat) and dissolved solid substrates. Vegetable oils, squalenes, and phosphatidylcholine were successfully hydrogenated on gram to kilogram scales.Catalytic hydrogenation is one of the most important methods for organic synthesis in both academia and industry. [1] It is widely used for the synthesis of natural products,b iologically important compounds, active pharmaceutical ingredients, and many intermediate compounds. The hydrogenation of fats, phospholipids,a nd squalenesi sp erformed to prevent oxidation of their unsaturated bonds, which causes coloration or odor. [2] The hydrogenated products thus prepared are used as emulsifiers, compoundinga gents, and so on. Hydrogenation of lecithin is an important process for the preparation of emulsifiers. Catalytic hydrogenation by using Pd/C has been used in ab atch system for this process;h owever,arelativelyh igh loading of Pd/C is required and subsequentr emoval of Pd by filtration is time consuming.M oreover,t he recovered Pd has low activity.T oa ddress thesei ssues, alternative catalyst systems have been investigated, and among the variousc atalysts tested, polysilane-supported Pd (Pd/PSi) was found to have high activity.W ed eveloped this methodology further, and herein, we describe ac ontinuous-flow hydrogenation process by using an ovel Pd/PSisystem as the catalyst.We previously prepared poly(methylphenyl)silane-supported Pd (Pd/MPPSi)a nd used it as ac atalyst for severalr eactions. [3] Poly(methylphenyl)silane was chosen as an analogue of polystyrene, because in microencapsulated [4] and polymer-incarcerated [5] catalysts with polystyrenes as polymer backbones, it is assumed that the benzene rings of the backbone are important for the immobilization of the metal catalysts through electronic interactions (p electrons). This reasoning led us to assumet hat benzene rings would also be important for immobilization of polysilane-supported catalysts, and poly(methylphenyl)silane was chosen accordingly.H owever,t he availability of poly(methylphenyl)silane is relatively limited. In contrast, poly(dimethyl)silane is readily available; [6] therefore, we examined the use of poly(dimethyl)silane in place of polystyrenes or poly(methylphenyl)silane as ab ackbone fors upported catalysts.We began our study by exploring the preparation of ap oly(dimethyl)silane-supported palladium/alumina hybrid catalyst [Pd/(DMPSi-Al 2 O 3 )] according to the method shown in Scheme 1. This methodw as based on ap rocedure that was used previously to preparet he Pd/MPPSi catalyst. [3] Unexpectedly,t he Pd loading of the catalyst (56.6...
A grating projection method is often used as a highly accurate 3D shape measurement method. A real-time 3D shape measurement system can also be applied to measure a wide and smooth curved surface, such as in sheet metal processing. In this case, operators take much effort to recognize the positions of some problem areas on an object from a measured result displayed on a monitor. This study develops a projection mapping system projecting an evaluation image, such as height, displacement, gradient, curvature factor, and area of defect, onto an object. These evaluation results are obtained from the measured 3D shape. The evaluation image should be deformed according to the 3D shape of the object because the camera and projector positions are different. Therefore, this study proposes a method to quickly produce a deformed evaluation image using a whole-space tabulation method. A coordinate transform table allowed the conversion of a camera pixel coordinate into a projector pixel coordinate by using reference planes to apply deformation to the evaluation image according to the measured 3D shape. The quick coordinate transformation from a camera pixel coordinate into a projector pixel coordinate was realized using the coordinate transform table. This is a key idea of this study. It was confirmed that the coordinate transformation from the camera pixel coordinate to the projector coordinate could be performed in 4.5 ms using the coordinate transform table. In addition, 3D shape measurement projection mapping was applied to a curved sheet metal with small deformation, and the deformation part was clearly shown by projecting the height distribution. The architecture and the experimental results are shown herein.
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