Physics-related epistemic uncertainties in proton depth dose simulation

A set of physics models and parameters pertaining to the simulation of proton energy deposition in matter are evaluated in the energy range up to approximately 65 MeV, based on their implementations in the Geant4 toolkit. The analysis assesses several features of the models and the impact of their associated epistemic uncertainties, i.e. uncertainties due to lack of knowledge, on the simulation results. Possible systematic effects deriving from uncertainties of this kind are highlighted; their relevance in relation to the application environment and different experimental requirements are discussed, with emphasis on the simulation of radiotherapy set-ups. By documenting quantitatively the features of a wide set of simulation models and the related intrinsic uncertainties affecting the simulation results, this analysis provides guidance regarding the use of the concerned simulation tools in experimental applications; it also provides indications for further experimental measurements addressing the sources of such uncertainties.Comment: To be published in IEEE Trans. Nucl. Sc

Med stereotypen som utgångspunkt: en studie om knivlagens tillämpningsproblematik

A knife is a tool which is used for both in- and outdoor purposes. Although wearing a knife in public areas is criminalized by Swedish law, the regulation includes several reservations about dispensations of judgement if the wearing is considered to be legitimated. The purpose of this study is to investigate and discuss the potential difficulties with the legal practice of the prohibition of knife wearing in public areas, based on the legal principle of equality before the law. All cases regarding knife wearing in the year of 2014 were collected from Malmö district court. The cases were quantified and coded with the purpose to convert it into statistical data. The statistical conclusions were interpreted by using theories about intersectionality, equality before the law, and unintended effects of the law. The result of the study shows that there are strong reasons to suppose an occurrence of discrimination in the legal process, where especially the initial selections of suspects are highly affected by false stereotypes regarding criminal tendency of people belonging to ethnic minorities

Observation of channeling for 6500 GeV/c protons in the crystal assisted collimation setup for LHC

Two high-accuracy goniometers equipped with two bent silicon crystals were installed in the betatron cleaning insertion of the CERN Large Hadron Collider (LHC) during its long shutdown. First beam tests were recently performed at the LHC with 450 GeV/c and 6500 GeV/c stored proton beams to investigate the feasibility of beam halo collimation assisted by bent crystals. For the first time channeling of 6500 GeV/c protons was observed in a particle accelerator. A strong reduction of beam losses due to nuclear inelastic interactions in the aligned crystal in comparison with its amorphous orientation was detected. The loss reduction value was about 24. Thus, the results show that deflection of particles by a bent crystal due to channeling is effective for this record particle energy.peer-reviewe

Bound-free pair production from nuclear collisions and the steady-state quench limit of the main dipole magnets of the CERN Large Hadron Collider

During its Run 2 (2015-2018), the Large Hadron Collider (LHC) operated at almost twice higher energy, and provided Pb-Pb collisions with an order of magnitude higher luminosity, than in the previous Run 1. In consequence, the power of the secondary beams emitted from the interaction points by the bound-free pair production (BFPP) process increased by a factor ~20, while the propensity of the bending magnets to quench increased with the higher magnetic field. This beam power is about 35 times greater than that contained in the luminosity debris from hadronic interactions and is focused on specific locations that fall naturally inside superconducting magnets. The risk of quenching these magnets has long been recognized as severe and there are operational limitations due to the dynamic heat load that must be evacuated by the cryogenic system. High-luminosity operation was nevertheless possible thanks to orbit bumps that were introduced in the dispersion suppressors around the ATLAS and CMS experiments to prevent quenches by displacing and spreading out these beam losses. Further, in 2015, the BFPP beams were manipulated to induce a controlled quench, thus providing the first direct measurement of the steady-state quench level of an LHC dipole magnet. The same experiment demonstrated the need for new collimators that are being installed around the ALICE experiment to intercept the secondary beams in the future. This paper discusses the experience with BFPP at luminosities very close to the future High Luminosity LHC (HL-LHC) target, gives results on the risk reduction by orbit bumps and presents a detailed analysis of the controlled quench experiment.Comment: 16 pages, 11 figure

Research on Mechanism of Formulation and Change of Stereotype: A Case Study of Hero Stereotype in Historical and Revolutionary Movies

刻板印象是人们头脑中关于世界的先在图景，是人们对社会某一类群体概括性的知识结构，它在社会互动中规范着人们的价值判断和行为反应。刻板印象一旦形成就具有了很强的稳定性。发源于西方的刻板印象研究已经有80多年的历史，其中，刻板印象的形成与变化研究是学者关注的热点之一。研究结果表明，社会关系、大众媒介以及个人心理结构是影响刻板印象形成与变化的主要因素。新中国成立以来，中国人认识社会的主要依据是革命历史影片塑造的英雄刻板印象。它为中国人民“提供了认识中国近代史的观念、方法和结论，同时也营造了利于浮现的、表象化的历史图景”。[1]本研究从刻板印象生成与变化的角度出发，探讨中国革命历史影片中英雄刻板印象的媒...It has been more than 80 years since the study of stereotyping emerged in western country. Defined as stored general knowledge on characteristics of a social group of people, stereotype is a kind of preconception about the world for people in their mind, which regulates their conduct and value judgment in their social interaction. Once it is formed, stereotype would have a strong stability, which ...学位：文学硕士院系专业：新闻传播学院广告学系_传播学学号：1052006115025

Overview of the FLUKA code

Abstract The capabilities and physics models implemented inside the FLUKA code are briefly described, with emphasis on hadronic interaction. Examples of the performances of the code are presented including basic (thin target) and complex benchmarks, and radiation detector specific applications. In particular the ability of FLUKA in describing existing calorimeter performances and in predicting those of future ones, as well as the use of the code for neutron and mixed field radiation detectors will be demonstrated with several examples

Supporting control programs on African swine fever in Ukraine through a knowledge, attitudes, and practices survey targeting backyard farmers

A Knowledge, Attitudes, and Practices (KAP) questionnaire was designed to collect information on farmers' knowledge of ASF and their practices surrounding that could impact the spread of the disease. The questionnaire was distributed, and data collected, from 233 backyard farmers from five selected Oblasts (Rivne, Kharkiv, Odessa, Zakarpattia and Kiev). Kruskal-Wallis tests were conducted to identify factors that could influence knowledge, and Dunn tests were performed to determine differences between groups when the Kruskal-Wallis tests were significant. Spearman tests were carried out to explore the association between knowledge and risky practices. Results show that comprehensive knowledge on ASF is not common in backyard farmers and that risky practices that influence the spread of ASF are regularly performed. Of the respondents, 47% felt well-informed about how ASF can be transmitted and 31.8% felt confident about recognizing clinical signs of ASF. The independent variable "Oblast" was identified as a significant factor (p = 0.0015) associated with differences in knowledge on clinical signs. We demonstrated statistically significant differences of knowledge between backyard farmers from different Oblasts. Knowledge of preventive measures was positively correlated with risky handling practices related to edible pork products (p = 0.0053) and non-edible pork products (p = 0.0417). In conclusion, our results show that backyard farmers have knowledge gaps on ASF and practice various risky behaviours that might favour the spread of the disease in Ukraine. There are regional differences in ASF knowledge and risky practices that should be taken into consideration in future evidence-based ASF prevention and control programs, including public awareness activities