Angular dependence of novel magnetic quantum oscillations in a quasi-two-dimensional multiband Fermi liquid with impurities

The semiclassical Lifshitz-Kosevich-type description is given for the angular dependence of quantum oscillations with combination frequencies in a multiband quasi-two-dimensional Fermi liquid with a constant number of electrons. The analytical expressions are found for the Dingle, thermal, spin, and amplitude (Yamaji) reduction factors of the novel combination harmonics, where the latter two strongly oscillate with the direction of the field. At the "magic" angles those factors reduce to the purely two-dimensional expressions given earlier. The combination harmonics are suppressed in the presence of the non-quantized ("background") states, and they decay exponentially faster with temperature and/or disorder compared to the standard harmonics, providing an additional tool for electronic structure determination. The theory is applied to Sr$_2$RuO$_4$.Comment: 5 pages, 2 figures, minor typos correcte

1, 2, 3, 4: Infusing Quantitative Literacy into Introductory Biology

Biology of the twenty-first century is an increasingly quantitative science. Undergraduate biology education therefore needs to provide opportunities for students to develop fluency in the tools and language of quantitative disciplines. Quantitative literacy (QL) is important for future scientists as well as for citizens, who need to interpret numeric information and data-based claims regarding nearly every aspect of daily life. To address the need for QL in biology education, we incorporated quantitative concepts throughout a semester-long introductory biology course at a large research university. Early in the course, we assessed the quantitative skills that students bring to the introductory biology classroom and found that students had difficulties in performing simple calculations, representing data graphically, and articulating data-driven arguments. In response to students' learning needs, we infused the course with quantitative concepts aligned with the existing course content and learning objectives. The effectiveness of this approach is demonstrated by significant improvement in the quality of students' graphical representations of biological data. Infusing QL in introductory biology presents challenges. Our study, however, supports the conclusion that it is feasible in the context of an existing course, consistent with the goals of college biology education, and promotes students' development of important quantitative skills

The Numerical Analysis of Viscous Flows on the Multiprocessor Computers

Abstract: The parallel algorithm for numerical simulation of viscous flows over complex shaped bodies is presented. Block structured grids are used. The time-stepping procedure is used to find steady-state solution of the full Navier-Stokes equations. The Godunov-Kolgan scheme for the inviscid terms are used, the central differences for approximation of viscous terms are used. The results of efficiency of parallel algorithm research are shown on the supersonic flow over the wing section and on the supersonic flow over the backward-facing step.Note: Research direction:Mathematical modelling in actual problems of science and technic

Numerical simulation of supersonic flows in the wing wake and its interaction with crossing shock waves

Abstract: The results of numerical simulation of supersonic flow in the wing wake and its interaction with shock waves investigation are presented. The system of couple counter wedges with a sharp edge has been used for the formation of shock waves of varying intensity. Investigation of regular and Mach interaction of shock waves has been performed. Calculations have been performed on a multiprocessor computer system K-100 in KIAM RAS. Experiments were carried out in a supersonic wind tunnel T–325 (ITAM SB RAS) at the Mach number 3.Note: Research direction:Mathematical modelling in actual problems of science and technic

Simulation of transition between regular and Mach shock waves reflections by an implicit scheme based on the LU-SGS and BiCGStab methods

Abstract: In this paper a parallel solver for 3D unsteady Reynolds-averaged Navier–Stokes equations with Spalart–Allmaras turbulence model is presented. The method is based on fully implicit finite volume scheme, which is solved by BiCGStab with LU-SGS as precondition. Using the developed method the transition between regular and Mach shock waves reflections initiated by energy input is simulated. Numerical results are compared with published data and with results of computations by the explicit scheme. The scalability of the proposed parallel numerical method is studied.Note: Research direction:Mathematical modelling in actual problems of science and technic

Numerical study of flow X-43 hypersonic aircraft using adaptive grids

Abstract: The results of the calculation of flow X-43 hypersonic aircraft using the original algorithm for constructing locally-adaptive grid to the structure of octree.Note: Research direction:Mathematical modelling in actual problems of science and technic

GridMan3D - a subroutine library for parallel computing on unstructured grids

Abstract: A subroutine library that facilitates the creation of programs for solving problems of mathematical physics on unstructured grids is presented. The library includes functions for reading the geometry data in CGNS format and for interprocessor data exchange via an MPI.Note: Research direction:Mathematical modelling in actual problems of science and technic

The Numerical Simulation of Subsonic Flows over Shaped Bodies.

Abstract: The algorithm for numerical simulation of subsonic flows over complex shaped bodies (extending up to a complete aircraft) is presented. The time-stepping procedure is used to find steady-state solution. Block structured grids are used. To achieve higher accuracy of Godunov scheme the piecewise linear distributions of flow variables are used. The parallel implementation of Euler solver on the multiprocessor system is discussed. The numerical results for the flow about the flying vehicle model for M=0.15 and several angle of attack values are presented. The comparison between experimental and numerical data is discussed.Note: Research direction:Mathematical modelling in actual problems of science and technic