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91.
This paper describes experiments carried out to determine the influence of dovetailed cross beams on the dimensional stability of a panel painting from the Middle Ages. Besides a serious cup (transverse distortion), the panel featured an unusual longitudinal distortion, a bow, mostly originating from bending in the proximity of the middle cross beam. Because of its localized occurrence, bending appeared to be caused by the crossbeam somehow pushing on the walls of its channel. Thanks to the cooperation offered by the curator and the restorer, some non-damaging tests were performed to measure the distortions of the panel, with and without the cross beams, after conditioning it in different climates. Processing and analysis of the measurement results demonstrated that the bow of the panel increases as the wood moisture content decreases. This led to the conclusion that the bow is actually produced by forces exerted by the cross beam along the panel's length, according to a mechanism named thrust transformation. By this mechanism the cross beam partly transforms the panel's tendency towards cupping, into a bow distortion. 相似文献
92.
Marco Antonio Rodriguez 《The Communication Review》2014,17(3):245-255
Aaron the Moor from Titus Andronicus and Ratonhnhaké:ton from Assassin’s Creed III are each aiding in a war against an international superpower, and both characters are plotting ways to advance and improve their respective culture. Aaron is seen as the villain and the antagonist, whereas Ratonhnhaké:ton is seen as an individual who fights for freedom. However, once both characters’ usefulness is exhausted, they are easily characterized as the Other and lose whatever benefits they may have earned. They are tossed aside by the factions they are trying to help. Even though Assassin’s Creed III is a video game, the same issues of colonialism and imperialism can be investigated in this 21st-century genre as in Shakespeare’s play. 相似文献
93.
94.
Luc Laberge Élise Ledoux Julie Auclair Marco Gaudreault 《Mind, Brain, and Education》2014,8(4):220-226
Adolescents who work while attending school are reported to sleep less than those who do not. This study aimed to identify factors associated with short sleep duration in students who work during the school year. A cross‐sectional survey aiming to describe working conditions and occupational safety and health was completed by representative samples of Quebec high school students aged 12–19 years from three administrative regions (n = 3,871). A multiple stepwise regression analysis was performed with sleep duration as the dependent variable, and sociodemographic, school, occupational, and health factors as potential explanatory variables. Significant factors associated with shorter sleep duration were later bedtimes (p < .001), shorter weekend oversleep (p < .001), higher physical work factors related to handling efforts (p < .001), and female gender (p < .01). Addressing work conditions of student workers may help prevent sleep deprivation. Special efforts should also target girls combining work and study. 相似文献
95.
This study examines the effect of antitrust regulation of patent consolidation on the development of follow-on innovations. Our reconciliation of the various strains of literature hypothesizes that in sectors where cumulative innovation is crucial to firms’ market operations, a firm that consolidates patents for substituting technologies for its already-possessed technologies discourages market competitions and follow-on innovation by competitors. In this case, antitrust regulation of patent consolidation is anticipated to positively affect competitors’ follow-on innovation. We empirically test this hypothesis with the case of the US Department of Justice's regulation of Novell's software patent transfers to four large proprietary software companies (i.e., Microsoft, Oracle, EMC, and Apple) in 2011. Our analyses using US patent, trademark, and copyright data have found evidence corroborating our hypothesis. Our research provides policy and scholarly implications regarding how antitrust law can be a complementary institution to the patent law for promoting innovation. 相似文献
96.
Ralph Bathurst Marco van Gelderen 《Journal of Higher Education Policy & Management》2014,36(4):395-407
In this paper, we explore the work life of a scholar new to academia in her methods of leading informally. We discuss five vignettes that offer moments of learning and reflection, including reducing performance anxiety, privileging financial accountability, the rise of the virtual world, the impact of silence, and the potential for confrontation to strengthen working relationships. We offer suggestions as to how contemporary leaders may adapt to the freedom that artful action offers. 相似文献
97.
本文从降低供应风险的角度,对2020年前我国原油进口结构的优化路径进行了定量分析。并且为应对伊朗原油出口的减少提出了数量化的政策建议。研究结论显示,由于我国对世界原油的需求将会持续旺盛,在未来几年内,我国需要大量增加从俄罗斯、科威特、阿联酋、卡塔尔、墨西哥及阿尔及利亚等传统产油国的进口,同时减少对沙特阿拉伯、安哥拉、苏丹和伊朗的原油依赖。从未来原油进口的地区分布上看,中东地区依然是我国原油进口的主要来源地,同时也是供应风险最大的地区。为应对伊朗石油禁运,我国应该增加从加拿大、墨西哥、尼日利亚和卡塔尔等国的原油进口来弥补供应缺口,并满足国内快速增长的原油消费需求。 相似文献
98.
Orloff ND Dennis JR Cecchini M Schonbrun E Rocas E Wang Y Novotny D Simmonds RW Moreland J Takeuchi I Booth JC 《Biomicrofluidics》2011,5(4):44107-441079
We present a 91 MHz surface acoustic wave resonator with integrated microfluidics that includes a flow focus, an expansion region, and a binning region in order to manipulate particle trajectories. We demonstrate the ability to change the position of the acoustic nodes by varying the electronic phase of one of the transducers relative to the other in a pseudo-static manner. The measurements were performed at room temperature with 3 μm diameter latex beads dispersed in a water-based solution. We demonstrate the dependence of nodal position on pseudo-static phase and show simultaneous control of 9 bead streams with spatial control of −0.058 μm/deg ± 0.001 μm/deg. As a consequence of changing the position of bead streams perpendicular to their flow direction, we also show that the integrated acoustic-microfluidic device can be used to change the trajectory of a bead stream towards a selected bin with an angular control of 0.008 deg/deg ± 0.000(2) deg/deg. 相似文献
99.
100.
Marco Moreira 《Assessment & Evaluation in Higher Education》1985,10(2):159-168
Concept maps are proposed as an alternative tool for evaluation in higher education and examples of concept maps, drawn by college students performing evaluation tasks, are presented in the areas of physics and literature. 相似文献