リンク集 RSS/ATOM 記事

Washington takes similar line to Russia and China as UN talks head towards conclusion without a deal

Israeli PM faces pressure from far-right coalition partners to proceed with assault on southern Gazan city

Environmental claims come under scrutiny, including the benefits of offsetting emissions from flying

McDonald’s and Coca-Cola among companies highlighting impact of persistent inflation

Former US president fined $9,000 for statements violating gag order and judge warns of potential jail time

Title: Computational Analysis and Regression Laws for Nozzle Erosion Prediction in Hybrid RocketsAuthors: Rotondi, Marco; Migliorino, Mario Tindaro; Bianchi, Daniele; Kamps, Landon; Nagata, HarunoriAbstract: The erosion of the nozzle throat can represent one of the major limitations against the future widespread use of hybrid rocket engines (HREs) in the space industry. In fact, nozzle erosion in HREs can be more severe and harder to predict than in solid rockets due to the higher concentration of oxidizing species in the combustion products and to mixture ratio shifts and/or throttling. Therefore, an accurate understanding of the erosion phenomenon is of fundamental importance for the technological advancement of HREs. This work is focused on the investigation of graphite nozzle erosion in HREs burning high-density polyethylene with two different oxidizers, oxygen and nitrous oxide. First, the results of a computational fluid dynamics parametric analysis are used to derive closed-form ...

2024年5月の特集「グリーン・ツーリズム」を掲載しました。

Title: A Single-Institution Prospective Study To Evaluate the Safety and Efficacy of Real-Time Image-Gated Spot-Scanning Proton Therapy (RGPT) for Prostate CancerAuthors: Nishioka, Kentaro; Hashimoto, Takayuki; Mori, Takashi; Uchinami, Yusuke; Kinoshita, Rumiko; Katoh, Norio; Taguchi, Hiroshi; Yasuda, Koichi; Ito, Yoichi M.; Takao, Seishin; Tamura, Masaya; Matsuura, Taeko; Shimizu, Shinichi; Shirato, Hiroki; Aoyama, HidefumiAbstract: Purpose: In real-time image-gated spot-scanning proton therapy (RGPT), the dose distribution is distorted by gold fiducial markers placed in the prostate. Distortion can be suppressed by using small markers and more than 2 fields, but additional fields may increase the dose to organs at risk. Therefore, we conducted a prospective study to evaluate the safety and short-term clinical outcome of RGPT for prostate cancer.Methods and Materials: Based on the previously reported frequency of early adverse events (AE) and the noninferiority margin of 10%, the requ ...

Title: Production of 45Ti radioisotope by proton irradiation of natural scandiumAuthors: Ditrói, F; Takács, S; Aikawa, M; Gantumur, D; Huang, H; Goto, S; Haba, H; Szűcs, Z; Tárkányi, FAbstract: 45Ti is a positron emitter radioisotope with weak gamma radiation. As its half-life (T1/2 = 3.08 h) is in the same range that of 18F and comparable with 43,44Sc, it is a good metallic alternative for radio-labelling of different proteins and other applications in nuclear medicine. The activation cross section and yield for possible production routes have been measured by several authors for decades, but probably because of its weak gamma-line and the different measurement techniques the results are very different and confusing. In the present work proton induced reactions are investigated to gain reliable activation cross section for the 45Ti production from naturally monoisotopic scandium. The study also resulted in production cross sections of 44g,44m,43Sc and 44Ti as side products. The r ...

Tie-up between two lenders would near valuation of Santander