Simulation of convective transport during frequency chirping of a TAE using the MEGA code

We present a procedure to examine energetic particle phase-space during long range frequency chirping phenomena in tokamak plasmas. To apply the proposed method, we have performed self-consistent simulations using the MEGA code and analyzed the simulation data. We demonstrate a travelling wave in phase-space and that there exist specific slices of phase-space on which the resonant particles lie throughout the wave evolution. For non-linear evolution of an n=6 toroidicity-induced Alfven eigenmode (TAE), our results reveal the formation of coherent phase-space structures (holes/clumps) after coarse-graining of the distribution function. These structures cause a convective transport in phase-space which implies a radial drift of the resonant particles. We also demonstrate that the rate of frequency chirping increases with the TAE damping rate. Our observations of the TAE behaviour and the corresponding phase-space dynamics are consistent with the Berk-Breizman (BB) theory.

Multidimensional Vibrations of Cable-Harnessed Beam Structures with Periodic Pattern: Modeling and Experiment

The dynamics of space structures is significantly impacted by the presence of power and electronic cables. Robust physical model is essential to investigate how the host structure dynamics is influenced by cable harnessing. All the developed models only considered the decoupled bending motion. Initial studies by authors point out the importance of coordinate coupling in structures with straight longitudinal cable patterns. In this article, an experimentally validated mathematical model is developed to analyze the fully coupled dynamics of beam with a more complex cable wrapping pattern which is periodic in nature. The effects of cable wrapping pattern and geometry on the system dynamics are investigated through the proposed coupled model. Homogenization-based mathematical modeling is developed to obtain an analogous solid beam that represents the cable wrapped system. The energy expressions obtained for fundamental repeating segment are transferred into the global coordinates consisting of several periodic elements. The coupled partial differential equations (PDE) are obtained for an analogous solid structure. The advantage of the proposed analytical model over the existing models to analyze the vibratory motion of beam with complex cable wrapping pattern has been shown through experimental validation.

Feto-mone Gender Paradigm in the Culture and Architecture of the Dawan Tribe Settlement in Kaenbaun Village

This article aimed to show the existence of gender concepts in the culture and settlement of the Dawan tribe in Kaenbaun Village, as indicated with its strong presence in the everyday life of the community, including the formal and ritual aspects. The concept exists in the inner world and mindset of every villager and has also become the guiding element of their world view, behaviour, place arrangement, and living space structures. This study was, there, conducted using participatory observation based on the Husserlian phenomenology paradigm supported by the inductive-empirical and qualitative descriptive methods to discover and understand the gender concept as well as its application and background in the selected tribe. The results showed the fetomone gender concept has become a paradigm of the thought expressed broadly and consistently through words, behaviour, as well as place and spatial arrangements among the villagers. Its function and meaning were further clarified in relation to the life and settlement architecture of the people. The core principle observed to be behind the concept is the separation and integration of life elements in an intense and permanent mutualism symbiotic relationship. Therefore, it was necessary to research the concept, function, and meaning of gender in ethnic cultures throughout Indonesia in order to form a collection of knowledge on gender and spatial planning which is useful to the understanding of ethnic settlements’ uniqueness based on local or ethnic perspectives and their preservation.

Coiling-Up Space Metasurface for High-Efficient and Wide-angle Acoustic Wavefront Steering

The recent advent of acoustic metasurface displays tremendous potential with their unique and flexible capabilities of wavefront manipulations. In this paper, we propose an acoustic metagrating made of binary coiling-up space structures to coherently control the acoustic wavefront steering. The acoustic wave steering is based on the in-plane coherent modulation of waves in different diffraction channels. The acoustic metagrating structure with a subwavelength thickness is realized with 3D printed two coiling-up space metaunits. By adjusting structural parameters of the metaunits, the −1st-order diffraction mode can be retained, and the rest of the diffraction orders are eliminated as much as possible through destructive interference, forming a high-efficiency anomalous reflection in the scattering field. The anomalous reflection performance of the designed metagrating is achieved over a wide range of incident angles with high efficiency.