Study the phase transition

In low-cost permanent magnet synchronous motor (PMSM) drive systems, the rotor position is usually estimated based on the back-electromotive force. However, such estimation methods have the common drawback of having large errors in low-speed regions. In order to solve that drawback in the startup phase, the I-f startup method is studied as its compatibility with the FOC control structure.

8p viyoko 01-10-2024 1 1   Download

Research objectives of the thesis: Clarification influence of the elements Na, Sr and Ba substituting for La/Ca and crystal size on the magnetic properties, phase transition and magnetocaloric effects of La0,7Ca0,3MnO3 materials. Found the materials for significant mmagnetocaloric parameters have potential for applications in magnetic refrigeration.Determine the effect of replacing Sr/Ba for Ca in La0,7Ca0,3MnO3 and Co substituting for Mn in La0,7Sr0,3MnO3 on their critical behavior as well as the ferromagnetic interactions order.

31p extraenglish 24-05-2021 24 4   Download

Basing on the Cornwall-Jackiw-Tomboulis (CJT) effective action approach, a theoretical formalism is established to study the Phase Transition in a binary mixture. The effective potential, which preserves the Goldstone theorem, is found in the Hartree-Fock (HF) approximation. This quantity is then used to consider the equation of state and the phase transition of the system.

11p larachdumlanat127 20-12-2020 11 2   Download

In this study, the authors will show that a semimetal-insulator phase transition may take place in the GaSb/InAs heterostructures due to the exciton pairing between the electrons and holes in the system. In the heterostructure, the top of the valence band of the InAs layer is higher than the bottom of the conduction band of the GaSb layer.

8p tamynhan9 02-12-2020 11 2   Download

This paper studies the influence of temperature 500 K, 1500 K, 2500 K, 3500 K and 4000 K on the microstructure and phase transition of a CaSiO3 bulk model using the Molecular Dynamics method with the Born-Mayer pair interaction potential and periodic boundary conditions.

10p tamynhan9 02-12-2020 14 2   Download

Phase transition and the Casimir effect are studied in the complex scalar field with one spatial dimension to be compactified. It is shown that the phase transition is of the second order and the Casimir effect behaves quite differently depending on whether it’s under periodic or anti-periodic boundary conditions.

9p tamynhan8 04-11-2020 12 2   Download

Influence of substitution of 3d metals for Mn on properties of La0.67Ca0.33Mn0.9 TM0.1O3 (TM = Fe, Co, Ni) compounds was studied. Ferromagnetic – paramagnetic and metals – insulator transitions were significantly affected by Mn-site substitution. However, no observable difference was found in their crystal structure from X-ray diffraction analysis. At room temperature the structure characterization of these compounds gave the single phase and structure is the distortion orthorhombic cell with space group symmetry Pnma.

12p 12120609 01-06-2020 13 2   Download

Besides introduction and conclusion, this thesis consists of 3 chapters. Chapter 1. Overview of Bose-Einstein condensate. Theory of BECs.Chapter 2. Interfacial tension and wetting phase transition in the system of BECs limited by one hard wall. Chapter 3. Finite-size effects of interfacial tension in the system of BECs limited by two hard walls.

28p cumeo2009 24-07-2018 43 2   Download

The study on the relationship between compositions and mechanical properties of the blends based on poly(vinyl chloride) (PVC), butadiene-acrylonitrile rubber (NBR) and natural rubber (NR) has been carried out. The result shows that in the presence of NBR, which plays role of transition phase between the two incompatible polymers PVC and NR, the tertiary phase polymer blends having high tensile strength and elongation at break were obtained.

4p uocvong04 24-09-2015 75 8   Download

The aims of thesis: studying of the phase structure of LSM and LSMq with two different forms of symmetry breaking term: the standard case and non – standard case; studying of the effect from neutrality condition on the phase structure of LSM and LSMq; studying of the chiral phase transition in compactified space

26p fujijudo87 07-07-2014 76 4   Download

Department of Medical Biochemistry and Biology, University of Bari, Italy; 2Department of Zoology, Laboratory of Histology and Comparative Anatomy, University of Bari, Italy; 3Center for the Study of Mitochondria and Energy Metabolism (CNR) Bari, Italy Mitochondrial bioenergetic impairment has been found in the organelles isolated from rat liver during the prereplicative phase of liver regeneration.

9p system191 01-06-2013 35 4   Download

The interaction of bacterial endotoxins [lipopolysaccharide (LPS) and the
endotoxic principle lipid A], with high-den-sity lipoprotein (HDL) from serum was investigated with a variety of physical techniques and biological assays. HDL exhibited an increase in the gel to liquid crystalline phase transition temperature Tc and a rigidification of the acyl chains of the endotoxins as measured by Fourier-transform infrared spectroscopy and differential scanningcalorimetry.

10p tumor12 22-04-2013 38 3   Download

Using synchrotron X-ray diffraction the thermal behaviour was studied of the cubic phases in the 1-monooleoyl-rac-glycerol (MO)/n-octyl-b-D-glucopyranoside (OG)/ 2 H2O system with 58 or 45 wt % MO concentration and varying OG/ 2 H2O contents. These MO contents correspond to a Pn3mcubic single-phase or aPn3mcubic phase in excess water on the binary MO/water axis of the ternary phase diagram. The cubic liquid crystalline phases are stable with small fractions of OG, while higher OG concentrations trigger a cubic-to-lamellar phase transition. ...

10p tumor12 20-04-2013 38 3   Download

In this paper, we develop an approach for establishing in some important cases, a conjecture made by De Giorgi more than 20 years ago. The problem originates in the theory of phase transition and is so closely connected to the theory of minimal hypersurfaces that it is sometimes referred to as “the version of Bernstein’s problem for minimal graphs”. The conjecture has been completely settled in dimension 2 by the authors [15] and in dimension 3 in [2], yet the approach in this paper seems to be the first to use, in an essential way, the solution of...

23p tuanloccuoi 04-01-2013 58 5   Download