Stability results for a soil model with singular hysteretic hydrology

We consider a differential equation describing the mass balance in a soil hydrology model with noninvertible Preisach-type hysteresis. We approximate the singular Preisach operator by regular ones and show, as main result, that the solutions of the regularized problem converge to a solution of the original one as the regularization parameter tends to zero. For monotone right hand sides, we prove that the solution is unique. If in addition the external water sources are time periodic, then we find sufficient conditions for the existence, uniqueness, and asymptotic stability of periodic solutions

Utilization of diffraction analysis in the study of martensitic weld deposits using tungsten carbide particles on S235JR+N steel

The durability of classic structural steels against various types of wear is generally low. Therefore, various types and combinations of resilient materials are constantly evolving, which are designed to reduce the cost of components replacement or repairs. This paper deals with the structures that are formed in a weld after addition of tungsten carbide particles to protect the surface of the components from wear. The resistance of the weld surface layer containing tungsten carbides is also evaluated in comparison with a layer without these particles

Analysis of coupled heat and moisture transfer in masonry structures

Evaluation of effective or macroscopic coefficients of thermal conductivity under coupled heat and moisture transfer is presented. The paper first gives a detailed summary on the solution of a simple steady state heat conduction problem with an emphasis on various types of boundary conditions applied to the representative volume element -- a periodic unit cell. Since the results essentially suggest no superiority of any type of boundary conditions, the paper proceeds with the coupled nonlinear heat and moisture problem subjecting the selected representative volume element to the prescribed macroscopically uniform heat flux. This allows for a direct use of the academic or commercially available codes. Here, the presented results are derived with the help of the SIFEL (SIimple Finite Elements) system.Comment: 23 pages, 11 figure

Virial coefficients and vapor-liquid equilibria of the EXP6 and 2-Yukawa fluids

Virial coefficients B₂ through B₄ and the vapor-liquid equilibria for the EXP6 and 2-Yukawa (2Y) fluids have been determined using numerical integrations and Gibbs ensemble simulations, respectively. The chosen 2Y models have been recently determined as an appropriate reference fluid for the considered EXP6 models.Вiрiальнi коефiцiєнти в iд B₂ до B₄ i фазова рiвновага пара - рiдина у EXP6 та 2-Юкава (2Y) плинах розрахованi, вiдповiдно, з допомогою чисельного iнтегрування та на основi комп’ютерного експерименту з використанням ансамблю Гiбса. Вибранi 2Y модельнi системи нещодавно були запропонованi як базиснi для EXP6 плинiв, що розглядаються

Postnatal Development of Blood Serum Concentrations of Immunoglobulin IgG, IgA and IgM Isotypes in Suckling Foal

Postnatal changes in concentrations of immunoglobulin IgG, IgM and IgA isotypes from birth until the age of five months were monitored by the ELISA method. The experiment was performed in a group of 52 thoroughbred foals and their mothers. Among the investigated animals, failure of colostral immunity transfer was recorded in only four foals (7.7 percent). The concentrations of immunoglobulin IgG and IgA isotypes primarily decreased during the first weeks of life and then gradually increased until the end of the investigated period. The concentrations of immunoglobulin IgG isotype reached the values of adult animals by the end of the investigated period. However, immunoglobulin IgA isotype did not reach those values during the entire investigated period. The concentrations of immunoglobulin IgM isotype were quite rapidly increasing from the birth on. The beginning of active antibody formation was inversely proportional to the level of colostral immunoglobulins