Effect of expansion coefficient difference between machine tool and workpiece to the thermal deformation induced by room temperature change

9th CIRP Conference on High Performance Cutting (HPC 2020)In the precision machining process, ambient temperature is maintained to 20 °C to minimize the thermal deformations. Much energy is consumed to maintain ambient temperature. The use of thermal compensation systems can minimize the energy consumption of room cooling systems. However, the influence of thermal deformation induced by room temperature upon workpieces is not clear. This paper investigates the effect of the linear expansion coefficient difference between a machine tool and workpieces to the thermal deformation induced by room temperature change. Machining experiments are conducted for steel and aluminum workpieces. The results agree with the calculation

Morphology‐Limited Free Carrier Generation in Donor/Acceptor Polymer Blend Solar Cells Composed of Poly(3‐hexylthiophene) and Fluorene‐Based Copolymer

The charge generation and recombination dynamics in polymer/polymer blend solar cells composed of poly(3-hexylthiophene) (P3HT, electron donor) and poly[2, 7-(9, 9-didodecylfluorene)-alt-5, 5-(4′, 7′-bis(2-thienyl)-2′, 1′, 3′-benzothiadiazole)] (PF12TBT, electron acceptor) are studied by transient absorption measurements. In the unannealed blend film, charge carriers are efficiently generated from polymer excitons, but some of them recombine geminately. In the blend film annealed at 160 °C, on the other hand, the geminate recombination loss is suppressed and hence free carrier generation efficiency increases up to 74%. These findings suggest that P3HT and PF12TBT are intermixed within a few nanometers, resulting in impure PF12TBT and disordered P3HT domains. The geminate recombination is likely due to charge carriers generated on isolated polymer chains in the matrix of the other polymer and at the domain interface with disordered P3HT. The undesired charge loss by geminate recombination is reduced by both the purification of the PF12TBT-rich domain and crystallization of the P3HT chains. These results show that efficient free carrier generation is not inherent to the polymer/fullerene domain interface, but is possible with polymer/polymer systems composed of crystalline donor and amorphous acceptor polymers, opening up a new potential method for the improvement of solar cell materials

3D-Plotting Algorithm for Insects using YOLOv5

In ecological research, accurately collecting spatiotemporal position data is a fundamental task for understanding the behavior and ecology of insects and other organisms. In recent years, advancements in computer vision techniques have reached a stage of maturity where they can support, and in some cases, replace manual observation. In this study, a simple and inexpensive method for monitoring insects in three dimensions (3D) was developed so that their behavior could be observed automatically in experimental environments. The main achievements of this study have been to create a 3D monitoring algorithm using inexpensive cameras and other equipment to design an adjusting algorithm for depth error, and to validate how our plotting algorithm is quantitatively precise, all of which had not been realized in conventional studies. By offering detailed 3D visualizations of insects, the plotting algorithm aids researchers in more effectively comprehending how insects interact within their environments

カバリング工程におけるカバード糸の被覆状態と糸張力に関する研究

取得学位：博士(工学)，学位授与番号：博甲第645号，学位授与年月日：平成16年3月25日,学位授与年：200

Th2およびTh17型免疫応答による消化管運動機能異常に関する研究

学位の種別:課程博士University of Tokyo(東京大学