Analytical description of stationary ideal MHD flows with constant total pressure

Incompressible stationary flows of ideal plasma are observed. By introduction of curvilinear system of coordinates in which streamlines and magnetic force lines form a family of coordinate surfaces, MHD equations are partially integrated and brought to a certain convenient form. It is demonstrated that the admissible group of Bogoyavlenskij's symmetry transformations performs as a scaling transformation for the curvilinear coordinates. Analytic description of stationary flows with constant total pressure is given. It is shown, that contact magnetic surfaces of such flows are translational surfaces, i.e. are swept out by translating one curve rigidly along another curve. Explicit examples of solutions with constant total pressure possessing a significant functional arbitrariness are given

Products of chemical reactions that occur during high-temperature heat treatment of the meat products

Recently the actively active studies have begun devoted to the accumulation of «harmful» substances in food products, which are supposedly accumulated in the body of a person who often consumes these products. Meat, as a source of full-featured animal protein, is especially popular in this aspect. For the preparation of meat products various types of heat treatment are used, almost each of which will inevitably lead to the destruction of some of the chemical compounds originally present in the product, and the formation of completely new chemical compounds, which can often be harmful to the human body. During high-temperature heat treatment (mainly frying), some chemical reactions in meat products occur, which lead to the formation of heterocyclic aromatic amines (HAA) in it. Due to the great variety of raw meat and cooking recipes, during the heat treatment HAA’s of various classes are formed, each of them will be peculiar for the particular type of raw material or recipe components (with the exception of MeIQx and PhIP, which always form during frying). The more complete understanding of the HAA’s formation mechanism will help study the products of Maillard reactions and Strecker degradation. In this work we studied the formation of HAA’s as a result of the cyclization of creatine and the detaching of water (dehydration) from it during temperature exposure. The classification of the compounds formed as a result of these reactions is presented and the main classes of the HAA obtained in result are considered. The questions of the influence of various factors on amount of HAA formed, such as the fat content, the introduction of Fe2+, Fe3+, are raised. In the future it is necessary to conduct studies of the quantitative content of HAA in meat products to complement the already actively ongoing work on the study of xenobiotics consumed by humans with food, which will give a more comprehensive picture of the carcinogens content in food products

Core of the Magnetic Obstacle

Rich recirculation patterns have been recently discovered in the electrically conducting flow subject to a local external magnetic termed "the magnetic obstacle" [Phys. Rev. Lett. 98 (2007), 144504]. This paper continues the study of magnetic obstacles and sheds new light on the core of the magnetic obstacle that develops between magnetic poles when the intensity of the external field is very large. A series of both 3D and 2D numerical simulations have been carried out, through which it is shown that the core of the magnetic obstacle is streamlined both by the upstream flow and by the induced cross stream electric currents, like a foreign insulated insertion placed inside the ordinary hydrodynamic flow. The closed streamlines of the mass flow resemble contour lines of electric potential, while closed streamlines of the electric current resemble contour lines of pressure. New recirculation patterns not reported before are found in the series of 2D simulations. These are composed of many (even number) vortices aligned along the spanwise line crossing the magnetic gap. The intensities of these vortices are shown to vanish toward to the center of the magnetic gap, confirming the general conclusion of 3D simulations that the core of the magnetic obstacle is frozen. The implications of these findings for the case of turbulent flow are discussed briefly.Comment: 14 pages, 9 figures, submitted to Journal of Turbulenc

Pharmacological correction of immune disorders in patients with chronic heart failure and ischemic heart disease

Currently, there are few data on the effect of cardiovascular drugs on the immune status of patients with heart failure (HF). This paper provides information on the impact of ß-adrenergic blocking agent (BAB), angiotensin-converting enzyme inhibitors (ACEI) on the maintenance of markers of immune inflammation in the blood, as well as on inhibition of synthesis of tumor necrosis factor-α (TNF-α) and on blocking of interaction between TNF-α and membrane receptor

Clinical efficacy of a betablockers therapy in patients with chronic heart failure on the background of postinfarction cardiosclerosis

Despite the fact that betablockers (BBs) are one of the main groups of therapy of patients with acute myocardial infarction (AMI), the comparative effectiveness of various BBs in patients with postinfarction cardiosclerosis (PICS) is uncertain. There was performed comparative analysis of clinical efficacy of BBs in patients with chronic heart failure (CHF) on the background of coronary heart disease (CHD), PICS. There was evaluated the impact of metoprolol succinate, carvedilol, bisoprolol and betaxolol on blood pressure (BP), left ventricular ejection fraction (LVEF), change the functional class of chronic heart failure, and mortality in patients over 4 year

Absolute and convective instabilities in an inviscid compressible mixing layer

We consider the stability of a compressible shear flow separating two streams of different speeds and temperatures. The velocity and temperature profiles in this mixing layer are hyperbolic tangents. The normal mode analysis of the flow stability reduces to an eigenvalue problem for the pressure perturbation. We briefly describe the numerical method that we used to solve this problem. Then, we introduce the notions of the absolute and convective instabilities and examine the effects of Mach number, and the velocity and temperature ratios of each stream on the transition between convective and absolute instabilities. Finally, we discuss the implication of the results presented in this paper for the heliopause stability.Comment: 5 pages, 6 figures, accepted by Astronomical Notes (Astron. Nachrichten

Flux and field line conservation in 3--D nonideal MHD flows: Remarks about criteria for 3--D reconnection without magnetic neutral points

We make some remarks on reconnection in plasmas and want to present some calculations related to the problem of finding velocity fields which conserve magnetic flux or at least magnetic field lines. Hereby we start from views and definitions of ideal and non-ideal flows on one hand, and of reconnective and non-reconnective plasma dynamics on the other hand. Our considerations give additional insights into the discussion on violations of the frozen--in field concept which started recently with the papers by Baranov & Fahr (2003a; 2003b). We find a correlation between the nonidealness which is given by a generalized form of the Ohm's law and a general transporting velocity, which is field line conserving.Comment: 9 pages, 2 figures, submitted to Solar Physic

Splitting technique for analytical modelling of two-phase multicomponent flow in porous media

In this paper we discuss one-dimensional models for two-phase Enhanced Oil Recovery (EOR) floods (oil displacement by gases, polymers, carbonized water, hot water, etc.). The main result presented here is the splitting of the EOR mathematical model into thermodynamical and hydrodynamical parts. The introduction of a potential associated with one of the conservation laws and its use as a new independent coordinate reduces the number of equations by one. The (n) × (n) conservation law model for two-phase n-component EOR flows in new coordinates is transformed into a reduced (n − 1) × (n − 1) auxiliary system containing just thermodynamical variables (equilibrium fractions of components, sorption isotherms) and one lifting equation containing just hydrodynamical parameters (phase relative permeabilities and viscosities). The algorithm to solve analytically the problem includes solution of the reduced auxiliary problem, solution of one lifting hyperbolic equation and inversion of the coordinate transformation. The splitting allows proving the independence of phase transitions occurring during displacement of phase relative permeabilities and viscosities. For example, the minimum miscibility pressure (MMP) and transitional tie lines are independent of relative permeabilities and phases viscosities. Relative motion of polymer, surfactant and fresh water slugs depends on sorption isotherms only. Therefore, MMP for gasflood or minimum fresh water slug size providing isolation of polymer/surfactant from incompatible formation water for chemical flooding can be calculated from the reduced auxiliary system. Reduction of the number of equations allows the generation of new analytical models for EOR. The analytical model for displacement of oil by a polymer slug with water drive is presented.Adolfo P. Pires, Pavel G. Bedrikovetsky, Alexander A. Shapir

Study of sedative tea phytocomplex within the framework of studies aimed at creation of a rectal dosage form with antihistaminic effect

We designed a new complex drug with antiallergic effect containing, in addition to the main component loratadine, a phytocomplex for an extra therapeutic effect. A collection of plants with sedative activity is chosen and the optimal agent for extraction of bioactive compound