Ferrofluid Flow in the Presence of Magnetic Dipole

The aim of this paper is to introduce new results on magneto-thermomechanical interaction between heated viscous incompressible ferrofluid and a cold wall in the presence of a spatially varying magnetic field. Similarity transformation is applied to convert the governing nonlinear boundary layer equations into coupled nonlinear ordinary differential equations. This system is numerically solved using higher derivative method. The effects of governing parameters corresponding to various physical conditions are investigated. Numerical results are represented for distributions of velocity and temperature, for dimensionless wall skin friction and for heat transfer coefficients. Two bifurcate solutions have been obtained and one of the two solutions compares well with previous studies

Formation of 3-Monochloro-1,2-Propanediol Fatty Acid Esters During Deep-Fat Frying of Pre-Fried Deep Frozen Food with Different Salt Content

Changes of edible oil quality factors and formation of 3-monochloro-1,2-propanediol fatty acid esters (3-MCPD-FE) during deep-fat frying in four different experiments (control, salt, pork chop, and chicken liver) with high oleic sunflower oil were compared in this study. Based on the results of investigated oil quality parameters, which were free fatty acid (FFA), anisidine value (AV), UV extinction at 232 and 268 nm (E232 and E268, respectively), and total polar material (TPM), only a modest deterioration of the frying oil was observed. As we expected, the 3-MCPD-FE content in the control samples did not reach the limit of quantification (0.1 mg kg–1), while the table salt itself caused a slight increase. The results of pork chop and chicken liver experiments were not statistically different from each other, after the third frying circle 0.52 and 0.39 mg kg–1 3-MCPD-FE levels were reached, respectively. Based on these values, the human exposure estimation resulted in a low risk

Gyakorlóiskola (1915) 4

Magyar Tanítóképző A Tanítóképző-intézeti Tanárok Országos Egyesületének közlönye - melléklet 30. évfolyam Budapest, 1915. április h

Gyakorlóiskola (1915) 5

Magyar Tanítóképző A Tanítóképző-intézeti Tanárok Országos Egyesületének közlönye - melléklet 30. évfolyam Budapest, 1915. május h

Ferrofluid Flow in the Presence of Magnetic Field Above Stretching Sheet

© 2019 Published by Faculty of Engineering. Magneto-thermomechanical interaction between heated viscous incompressible ferrofluid and a cold wall in the presence of a spatially varying magnetic field is investigated. A model for two dimensional ferrofluid flows is constructed. The influence of magnetic dipole in a Newtonian ferrofluid is characterized. The dynamic response of heated ferrofluid in a non-uniform magnetic field is studied along a nonlinearly stretching sheet with changing surface temperature. The nonlinearity is considered as power law relationship. Similarity transformation is applied to convert system of partial differential equations into ordinary differential equations and then solved numerically. The impact of the parameters on the velocity and temperature are explored numerically. It is found that the magneto-thermomechanical interaction slows down the motion of fluid particles. At the surface, the skin friction coefficient decreases and the rate of heat transfer increases with increasing ferromagnetic parameter or with increasing power law exponent

Hilbert Space Structures on the Solution Space of Klein-Gordon Type Evolution Equations

We use the theory of pseudo-Hermitian operators to address the problem of the construction and classification of positive-definite invariant inner-products on the space of solutions of a Klein-Gordon type evolution equation. This involves dealing with the peculiarities of formulating a unitary quantum dynamics in a Hilbert space with a time-dependent inner product. We apply our general results to obtain possible Hilbert space structures on the solution space of the equation of motion for a classical simple harmonic oscillator, a free Klein-Gordon equation, and the Wheeler-DeWitt equation for the FRW-massive-real-scalar-field models.Comment: 29 pages, slightly revised version, accepted for publication in Class. Quantum Gra

General Aspects of PT-Symmetric and P-Self-Adjoint Quantum Theory in a Krein Space

In our previous work, we proposed a mathematical framework for PT-symmetric quantum theory, and in particular constructed a Krein space in which PT-symmetric operators would naturally act. In this work, we explore and discuss various general consequences and aspects of the theory defined in the Krein space, not only spectral property and PT symmetry breaking but also several issues, crucial for the theory to be physically acceptable, such as time evolution of state vectors, probability interpretation, uncertainty relation, classical-quantum correspondence, completeness, existence of a basis, and so on. In particular, we show that for a given real classical system we can always construct the corresponding PT-symmetric quantum system, which indicates that PT-symmetric theory in the Krein space is another quantization scheme rather than a generalization of the traditional Hermitian one in the Hilbert space. We propose a postulate for an operator to be a physical observable in the framework.Comment: 32 pages, no figures; explanation, discussion and references adde

TESS first look at evolved compact pulsators. Known ZZ Ceti stars of the southern ecliptic hemisphere as seen by TESS

Context. We present our findings on 18 previously known ZZ Ceti stars observed by the TESS space telescope in 120 s cadence mode during the survey observation of the southern ecliptic hemisphere. Aims: We focus on the frequency analysis of the space-based observations, comparing the results with findings of previous ground-based measurements. The frequencies detected by the TESS observations can serve as inputs for future asteroseismic analyses. Methods: We performed standard pre-whitening of the data sets to derive the possible pulsation frequencies of the different targets. In some cases, we fit term amplitude or phase variations that occurred during the TESS observations. Results: We detected more than 40 pulsation frequencies in seven ZZ Ceti stars observed in the 120 s cadence by TESS, with precision better than 0.1 μHz. We found that HE 0532-5605 may be a new outbursting ZZ Ceti. Ten targets do not show any significant pulsation frequencies in their Fourier transforms, due to a combination of their intrinsic faintness and/or crowding on the large TESS pixels. We also detected possible amplitude or phase variations during the TESS observations in some cases. Such behaviour in these targets was not previously identified from ground-based observations

Krein-Space Formulation of PT-Symmetry, CPT-Inner Products, and Pseudo-Hermiticity

Emphasizing the physical constraints on the formulation of a quantum theory based on the standard measurement axiom and the Schroedinger equation, we comment on some conceptual issues arising in the formulation of PT-symmetric quantum mechanics. In particular, we elaborate on the requirements of the boundedness of the metric operator and the diagonalizability of the Hamiltonian. We also provide an accessible account of a Krein-space derivation of the CPT-inner product that was widely known to mathematicians since 1950's. We show how this derivation is linked with the pseudo-Hermitian formulation of PT-symmetric quantum mechanics.Comment: published version, 17 page