The structure solution of the F-type i-ZnMgHf from the X-ray diffraction

ABSTRACT

We report a successful growth of the ZnMgHf F-type icosahedral quasicrystal in the form of faceted single grains. By varying the heat treatment parameters we were able to obtain single crystals with a quality suitable for a single crystal X-ray diffraction which was conducted in a synchrotron facility. Ab initio structure solution by a charge flipping algorithm manifests the existence of two types of Bergman clusters. Clusters are differentiated by the preferential occupation of the high-symmetry positions by hafnium in a rhombic triacontahedron, being the outer shell of the atomic cluster.

This paper is part of a Thematic Issue on The Crystallographic Aspects of Metallic Alloys.     

Runtime verification of autopilot systems using a fragment of MTL- $${\int }$$

International Journal on Software Tools for Technology Transfer - Current real-time embedded systems development frameworks lack support for the verification of properties using explicit time where...     

A Non-Invasive Technique for Online Defect Detection on Steel Strip Surfaces

During the production of steel strips, a large amount of surface defects can be generated, due to harsh environmental conditions. A high number of surface defects can lead to rejection by the customer, which represents significant economic losses to the production plant. Thus, it is very important to detect the presence and type of the defects generated during the production of each steel strip. Using this information, it is possible to determine whether a strip is suitable for sale, and it may also be useful to determine the origin of defects and, if possible, prevent them from being generated in subsequent strips. To perform these tasks, non-invasive inspection techniques are usually used, carried out automatically by artificial vision systems. Although the inspection conducted by humans is more accurate, they become fatigued quickly, or may even be unable to carry out the inspection correctly when the forward speed of the strip is high. In this paper, a new detection technique is proposed, based on the division of an image into a set of overlapping areas. The optimum values for the configuration parameters of the detection technique are automatically determined using a genetic algorithm. After the detection phase, all the defects are classified using a neural network. A very satisfactory success rate has been achieved in both detection and classification phases.     

Classroom ventilation and indoor air quality—results from the FRESH intervention study

Inadequate ventilation of classrooms may lead to increased concentrations of pollutants generated indoors in schools. The FRESH study, on the effects of increased classroom ventilation on indoor air quality, was performed in 18 naturally ventilated classrooms of 17 primary schools in the Netherlands during the heating seasons of 2010–2012. In 12 classrooms, ventilation was increased to targeted CO₂ concentrations of 800 or 1200 ppm, using a temporary CO₂ controlled mechanical ventilation system. Six classrooms were included as controls. In each classroom, data on endotoxin, β(1,3)‐glucans, and particles with diameters of <10 μm (PM₁₀) and <2.5 μm (PM_2.5) and nitrogen dioxide (NO₂) were collected during three consecutive weeks. Associations between the intervention and these measured indoor air pollution levels were assessed using mixed models, with random classroom effects. The intervention lowered endotoxin and β(1,3)‐glucan levels and PM₁₀ concentrations significantly. PM₁₀ for instance was reduced by 25 μg/m³ (95% confidence interval 13–38 μg/m³) from 54 μg/m³ at maximum ventilation rate. No significant differences were found between the two ventilation settings. Concentrations of PM_2.5 and NO₂ were not affected by the intervention. Our results provide evidence that increasing classroom ventilation is effective in decreasing the concentrations of some indoor‐generated pollutants.     

Study on spiral wall thickness unevenness of thin- walled tubes rolled by Assel rolling mill

In view of the internal thread defect of thin- walled tubes rolled by Assel 3- roll skew rolling mill, Assel cross- rolling process of X20Cr13 steel tube with typical specification of ??160mm??6. 5mm was numerically simulated by using 3D finite element analysis software Simufact. The influences of different mandrel movement modes, feeding angles and rolling strip profiles on the depth of internal thread were studied. The results show that the depth of the internal thread of steel tube rolled by the full floating mandrel is the most shallow, the second is that of the fixed mandrel and that of the pull mandrel is worst, and it will be gradually deepened when the feed angle increases; the hyperbolic rolling strip is more conducive to controlling the internal thread depth of the rolled tube. Under the condition of hyperbolic rolling strip, the amount of twist deformation of the rolled tube in the rolling process is about 35% smaller than that of the straight rolling strip.     

微创治疗颈椎间盘突出37例

【摘要】 目的 探讨经皮穿刺颈椎间盘髓核切除术（percutaneous cervical discectomy，PCD）联合低温等离子消融术（percutaneous nucleoplasty，PCN）治疗颈椎间盘突出的临床应用。方法 在C型臂X线机引导下，选择颈部前外侧经气管、食管与颈动脉鞘之间入路，用穿刺针插入椎间盘中心，然后依次使用椎间盘旋切系统及等离子消融系统治疗颈椎间盘突出患者37例。结果 治疗37例患者，1例手术失败，有效率为80．6％；1例等离子刀头断裂，但随访无后遗症。结论 PCD联合PCN治疗颈椎间盘突出具有创伤小、痛苦少、安全性高、恢复快等特点，是治疗颈椎间盘突出的有效方法之一。

     

Empirical study on Game Transfer Phenomena in a location-based augmented reality game

Research on Game Transfer Phenomena (GTP) has demonstrated that playing video games can lead to re-experiencing images, sounds, tactile sensations, spontaneous thoughts and actions, sometimes triggered by physical objects/events associated with the game. Location-based augmented reality games posit interesting questions regarding GTP, particularly because they use physical locations, they overlay digital images in physical contexts and the gameplay shifts between the virtual and the physical world. This study aims to investigate the prevalence of GTP and the role of immersion, augmented reality and sound in a sample of English- (EnS) and Spanish- (SpS) speaking gamers of the game Pokémon Go (PoGo). A total of 1313 gamers (M_age?=?31.47) were recruited online. GTP was less common than in previous studies; however, 82.4% had experienced GTP at least once. The SpS showed higher prevalence of GTP and played more intensively. Automatic mental processes predominated in the EnS, while behaviours and actions were more common in the SpS. The absence or presence of video game features seems important for the way GTP manifests. For instance, tactile hallucinations were more prevalent, while sensations of self-motion were less reported. Playing with augmented reality (AR) and sounds showed significant correlations with various GTP types, but not with re-experiencing images from the game. More gamers who reported the sensation that Pokémon were physically present or looked for Pokémon outside the screen while playing, as connotations of immersion, had experienced GTP. Experiencing GTP while playing may be more common in location-based augmented reality games, compared to other games.