Self-Directed Learning Contention: Student and Faculty Views

Self-directed learning (SDL) is a pedagogical technique that is commonly practiced within the framework of project-based learning (PjBL) SDL has been found to be useful in the development of skills necessary for engineering careers, including open-ended problem-solving, life-long learning, and critical thinking. Implemented in a variety of ways, SDL is primarily characterized by developing student autonomy. According to Stefanou et al.\u27s framework, student autonomy can be promoted at three different levels: organizational, procedural, and cognitive. These three levels include varying degree of student choice: organizational autonomy takes into account the environment (e.g., due dates), procedural autonomy incorporates form (e.g., deliverable form), and cognitive autonomy involves content (e.g., designing projects). This range of possible SDL experiences allows for a wide interpretation of the role and value of SDL and student autonomy by both students and faculty. Using methods of grounded theory, three research questions were addressed: (a) How do the pedagogical practices in the first-year mathematics, physics, and engineering classes fit into Stefanou et al.\u27s autonomy framework? (b) How does the level of student autonomy impact student\u27s participation, interest, and perception of performance in these classrooms? and (c) How do student and faculty perspectives on student autonomy affect the classroom environment? Our results indicate that students and faculty have mixed feelings regarding SDL, which drive frustration and discomfort with open-ended learning in the classroom. In general, students often do not feel well-supported in SDL environments and exhibit a lowered sense of competency and expectancy. On the other hand, faculty present blindness towards structural supports necessary for effective SDL classroom environment and specifically their own roles in scaffolding students\u27 SDL experiences

Dynamical signature of the Mott-Hubbard transition in Ni(S,Se)_2

The transition metal chalcogenide Ni(S,Se)_2 is one of the few highly correlated, Mott-Hubbard systems without a strong first-order structural distortion that normally cuts off the critical behavior at the metal-insulator transition. The zero-temperature (T) transition was tuned with pressure, and significant deviations were found near the quantum critical point from the usual T^(1/2) behavior of the conductivity characteristic of electron-electron interactions in the presence of disorder. The transport data for pressure and temperature below 1 kelvin could be collapsed onto a universal scaling curve

Liquid-crystal imaging of molecular-tilt ordering in self-assembled lipid tubules

Self-assembled cylindrical tubules of chiral phospholipids are interesting supramolecular structures. Understanding the molecular-tilt order is a key step in controlling the size and shape of the tubules and designing new functional materials. The current theories based on the chiral interactions, coupled with molecular tilt, have predicted that the tubules could have both uniform and modulated tilt states. Here, we image the molecular-tilt order in the self-assembled tubules of a chiral phospholipid by using liquid crystals as an optical amplification probe. We demonstrate that the organization of the molecular-tilt azimuth in the lipid tubules can induce an azimuthal orientation in the liquid crystals. Both uniform and modulated tilt states of the lipid tubules are observed after liquid-crystal optical amplification

Shape selection of twist-nematic-elastomer ribbons

How microscopic chirality is reflected in macroscopic scale to form various chiral shapes, such as straight helicoids and spiral ribbons, and how the degree of macroscopic chirality can be controlled are a focus of studies on the shape formation of many biomaterials and supramolecular systems. This article investigates both experimentally and theoretically how the chiral arrangement of liquid crystal mesogens in twist-nematic-elastomer films induces the formation of helicoids and spiral ribbons because of the coupling between the liquid crystalline order and the elasticity. It is also shown that the pitch of the formed ribbons can be tuned by temperature variation. The results of this study will facilitate the understanding of physics for the shape formation of chiral materials and the designing of new structures on basis of microscopic chirality