Anomalous Roughening of Viscous Fluid Fronts in Spontaneous Imbibition

We report experiments on spontaneous imbibition of a viscous fluid by a model porous medium in the absence of gravity. The average position of the interface satisfies Washburn's law. Scaling of the interface fluctuations provides a dynamic exponent z \simeq 3, indicative of global dynamics driven by capillary forces. The complete set of exponents clearly shows that interfaces are not self-affine, exhibiting distinct local and global scaling, both for time (b=0.64\pm 0.02, b* =0.33 \pm 0.03) and space (a=1.94 \pm 0.20, a_loc=0.94 \pm 0.10). These values are compatible with an intrinsic anomalous scaling scenario.Comment: 4 pages, 5 figure

Agricultural, forest and rural policy sectors' receptiveness to agroforestry intercropping systems in Quebec (Canada)

PosterIn Quebec (Canada), intercropping trees and crops is a new practice in the agricultural landscape dominated by conventional monocropping systems. As research goes on and slowly reveals the potential of these systems to address some key issues in agriculture, forestry and rural development, and as farmers’ awareness increases, there is a pressing need to find public support for these systems. In order to help the promoters of agroforestry intercropping systems in their search of support in the political arena, we conducted a comparative study of the receptiveness of the agricultural, forest and rural policy sectors to these systems. As the literature on public policy processes has stressed the importance of policy stakeholders’ ideas in the implementation of new policies, we used a conceptual framework based on cognitive schemes to compare the ideas driving these policy sectors with the ideas supporting agroforestry intercropping systems. Results based on the analysis of formal publications and semi-directed interviews conducted with agroforestry experts and policy stakeholders underline that agroforestry intercropping systems are mostly featured by their promoters as sustainable and multifunctional systems. The rural policy sector has proven to be the most receptive and the forest sector the less receptive, while the agricultural sector lies in-between, offering small-scale support to agroforestry intercropping systems. The analysis highlights that policy sectors integrating multifunctionality in their core ideas are supportive of agroforestry intercropping systems, while sectors remaining largely focused on specialization and productivity are less receptive. Our study also shows that public incentives might not be sufficient to drive the adoption of agroforestry intercropping systems since major barriers to their implementation remain in some policy sectors. Featuring these systems as productive might be a necessary argument shift to tear down policy barriers and increase public support

Physical Education Teachers\u27 Experiences With Remote Instruction During The Initial Phase Of The Covid-19 Pandemic

This study investigated physical education (PE) teachers\u27 experiences with remote instruction in the United States during the initial outbreak of COVID-19. PE teachers (n = 4,362) from all 50 states completed a survey identifying their experiences with remote instruction in May, 2020. Survey responses were analyzed by geographic region, district type, and school level. Teachers reported having students submit assignments (51% yes), using video instruction (37% yes), being less effective when instructing remotely (20% yes), and emphasizing student outcomes focused on health-related fitness (32% yes), and physical activity value/ enjoyment (43% yes). Access to technology (40% yes) and required student assignments (43% yes) were lowest among teachers from the South. Rural teachers reported the least access to technology (37% yes) and rated themselves as least effective (24% yes). Secondary level teachers reported the highest percentage of required assignments (84% yes). Teachers\u27 responses identify unique challenges to delivering equitable and effective remote PE instruction

Teegi: Tangible EEG Interface

We introduce Teegi, a Tangible ElectroEncephaloGraphy (EEG) Interface that enables novice users to get to know more about something as complex as brain signals, in an easy, en- gaging and informative way. To this end, we have designed a new system based on a unique combination of spatial aug- mented reality, tangible interaction and real-time neurotech- nologies. With Teegi, a user can visualize and analyze his or her own brain activity in real-time, on a tangible character that can be easily manipulated, and with which it is possible to interact. An exploration study has shown that interacting with Teegi seems to be easy, motivating, reliable and infor- mative. Overall, this suggests that Teegi is a promising and relevant training and mediation tool for the general public.Comment: to appear in UIST-ACM User Interface Software and Technology Symposium, Oct 2014, Honolulu, United State

Dual equilibrium in a finite aspect ratio tokamak

A new approach to high pressure magnetically-confined plasmas is necessary to design efficient fusion devices. This paper presents an equilibrium combining two solutions of the Grad-Shafranov equation, which describes the magnetohydrodynamic equilibrium in toroidal geometry. The outer equilibrium is paramagnetic and confines the inner equilibrium, whose strong diamagnetism permits to balance large pressure gradients. The existence of both equilibria in the same volume yields a dual equilibrium structure. Their combination also improves free-boundary mode stability

The effects of room design on computer-supported collaborative learning in a multi-touch classroom.

While research indicates that technology can be useful for supporting learning and collaboration, there is still relatively little uptake or widespread implementation of these technologies in classrooms. In this paper, we explore one aspect of the development of a multi-touch classroom, looking at two different designs of the classroom environment to explore how classroom layout may influence group interaction and learning. Three classes of students working in groups of four were taught in the traditional forward-facing room condition, while three classes worked in a centered room condition. Our results indicate that while the outcomes on tasks were similar across conditions, groups engaged in more talk (but not more off-task talk) in a centered room layout, than in a traditional forward-facing room. These results suggest that the use of technology in the classroom may be influenced by the location of the technology, both in terms of the learning outcomes and the interaction behaviors of students. The findings highlight the importance of considering the learning environment when designing technology to support learning, and ensuring that integration of technology into formal learning environments is done with attention to how the technology may disrupt, or contribute to, the classroom interaction practices

Real time plasma equilibrium reconstruction in a Tokamak

The problem of equilibrium of a plasma in a Tokamak is a free boundary problemdescribed by the Grad-Shafranov equation in axisymmetric configurations. The right hand side of this equation is a non linear source, which represents the toroidal component of the plasma current density. This paper deals with the real time identification of this non linear source from experimental measurements. The proposed method is based on a fixed point algorithm, a finite element resolution, a reduced basis method and a least-square optimization formulation

Nitrogen leaching from organic agriculture and conventional crop rotations (France)

A great challenge to science is to elucidate how agriculture can feed the increasing world population without damaging the environment, while preserving other resources such as freshwater. In the Seine basin, characterised by intensive agriculture, most of surface and underground water is contaminated by nitrate. Conventional agriculture has regularly increased the use of industrial fertilisers since the WWII, leading to high nitrogen leaching, as shown by lysimeters or suction cup measurements. Such measurements are very scarce for other agricultural systems such as organic farming (Hansen et al. 2000; Haas et al. 2002; Mondelaers et al. 2009). The goal of our study is to investigate nitrogen leaching from organic agriculture, taking into account complete organic rotations (6-9 years). We hypothesize that leaching for organic farming is less than for conventional farming, although factors such as different practices, types of soil and age of conversion need to be taken into consideration. This work should have an impact on nitrogen sufficiency and management of organic practices