Wave instability of a magnetic fluid surface at the boundary with water in an electric field

Свойства межфазной поверхности магнитной жидкости на границе с водой в электрическом поле изучались во многих работах. Были обнаружено изменение отражательной способности межфазной поверхности вода – магнитная жидкость в электрическом поле, что авторами связывается с образованием на межфазной границе слоя плотноупакованных частиц. По оптическим и электрическим измерениям оценена толщина d этого слоя. Интерес к этим эффектам, помимо чисто академического, связан с возможностью управления поведением межфазной границы раздела магнитного коллоида и гомогенной жидкости внешним электрическим полем, что представляет практический интерес, поскольку слой частиц магнетита на межфазной поверхности может быть интерпретирован как жидкая мембрана с особыми свойствами. Задача настоящего исследования – теоретически показать, что образование слоя частиц дисперсной фазы магнитной жидкости в электрическом поле и связанное с этим уменьшение межфазного натяжения является определяющим фактором для развития волновой неустойчивости. A layer of close-packed particles of a dispersed phase (magnetite) with a protective shell of oleic acid is formed on the interface of a weakly conducting magnetic colloid (magnetic fluid) and water in a perpendicular electric field. The formation of a layer leads to a decrease in the interfacial tension. When the magnetic particles come into contact with the electrode surface, the electrochemical interaction of oleic acid molecules surrounding the particle with water occurs. As a result of the reaction, released ions charge the surface layer. After some time, the particles in the layer get recharged and repelled from the interface. This leads to wave instability. This paper considers the mathematical modeling of instability in the form of a boundary value problem – a dispersion equation. The determining factor in the development of wave instability is the action of the electric field, the formation of the near-electrode layer and, as a consequence, a decrease in the interfacial tension.

Disassembling the Nature of Capsid: Biochemical, Genetic, and Imaging Approaches to Assess HIV-1 Capsid Functions

The human immunodeficiency virus type 1 (HIV-1) capsid and its disassembly, or capsid uncoating, has remained an active area of study over the past several decades. Our understanding of the HIV-1 capsid as solely a protective shell has since shifted with discoveries linking it to other complex replication events. The interplay of the HIV-1 capsid with reverse transcription, nuclear import, and integration has led to an expansion of knowledge of capsid functionality. Coincident with advances in microscopy, cell, and biochemistry assays, several models of capsid disassembly have been proposed, in which it occurs in either the cytoplasmic, nuclear envelope, or nuclear regions of the cell. Here, we discuss how the understanding of the HIV-1 capsid has evolved and the key methods that made these discoveries possible.

Installation of Bored Piles with a Protective Silicate Shell of a New Design in Saline Silty-Clayey Soils

Designing advanced methods of corrosion protection and increasing the bearing capacity of pile foundations on saline clayey soils is a priority geotechnical task in Kazakhstan. The formation of a suffusion-resistant waterproof shell was achieved by silicatization of a borehole before concreting, by the installation of a mold into the borehole and the impregnation of a sodium silicate solution into the space between the mold and the soil under pressure. After coagulation of the silicate solution, the mold was removed and the formed shell was filled with corrosion-resistant concrete. Full-scale static pile load tests were conducted in the construction site “Retaining wall on Mount Koktobe” in Almaty. The bearing capacity of the piles with the protective silicate shell exceeded the bearing capacity of an ordinary pile by 2.5 times on average without wetting the site, and 3.2 times after prolonged wetting. The numerical model had a close relationship with the average experimental curve obtained when conducting six static pile load tests with the protective shell. A large economic effect of the developed piling technology with a protective shell was achieved, with a significant reduction in the cost of piling, equal to 27.85%.

PHYSICOCHEMICAL AND ELECTROCHEMICAL METHODS FOR MODIFYING THE PROPERTIES OF DIAMONDS AND ORE PULP COMPONENTS DURING THE SEPARATION OF DIAMOND-BEARING KIMBERLITES

The main deposits of kimberlite ores located in the regions of Western Yakutia are enriched at the ALROSA diamond extraction factories using a similar technology, in which the maximum completeness of extraction and safety of diamond crystals is ensured by the stages of schemes. The bulk of diamond crystals is extracted in the processes of heavy medium, sticky and foam separation, the effectiveness of which is determined by the properties of diamonds, kimberlite minerals and the media separating them. The article presents the results of theoretical and experimental studies carried out by ICEMR RAS together with the largest universities in Russia, scientific and industrial enterprises of ALROSA. It is shown that the use of combined energy methods of destruction and removal of hydrophilizing formations on diamond crystals provides hydrophobization of their surface in the processes of sticky and foam separation. It has been established that the efficiency and economic indicators of the process of dense medium separation of diamond-containing raw materials are due to the stability of the technological properties of the weighting agent of the ferrosilicon medium and the suspension prepared on its basis. The method for modifying the corrosion resistance of ferrosilicon by nitriding its surface has been substantiated and tested. The proposed method makes it possible to create a protective shell on the surface of the granules, preventing their destruction upon contact with corrosive components of the water-air environment. Semi-industrial tests have established the possibility of increasing the extraction of diamonds into concentrates for sticky and foam separation by 4 and 5.2%, respectively. The results of laboratory tests have confirmed the possibility of reducing the corrosion rate of ferrosilicon by 5-6 times in the process of dense medium separation.

The Secret of Love

In the game of drive, the Eros has the role of psychically binding excitations, so that a tolerable quantity of psychic energy is maintained, avoiding a traumatic spill of libidinal energy. Freud discovers the possibility of impulse entanglement by directing destructiveness outwards through the action of the libido. When the child is insufficiently invested by the environment he develops in, his psychism will develop on a fragile foundation. This frailness can be encapsulated in a rigid protective shell that will not allow for authentic development. We speak of a narcissistic deficit that leads either to an internal dynamic that aims to repair the deficit of primary investment, or to an internal dynamic that perpetuates this deficit. Defense mechanisms specific to narcissistic functioning are idealization and devaluation, and the need for reparation can emerge only after acknowledgement of the narcissistic wound. The sentiment of one’s own worth is disturbed in both situations, the identity nucleus itself being affected. The person would feel shame, sentiments of inferiority, permanently in need of reassurance regarding his/her worth. The capacity to love will be conditioned by the establishment of a good contact with the authentic self, through valuing the self, recognizing one’s own needs and identities.

Different solutions lead to similar life history traits across the great divides of the amniote tree of life

Amniote vertebrates share a suite of extra-embryonic membranes that distinguish them from anamniotes. Other than that, however, their reproductive characteristics could not be more different. They differ in basic ectothermic vs endothermic physiology, in that two clades evolved powered flight, and one clade evolved a protective shell. In terms of reproductive strategies, some produce eggs and others give birth to live young, at various degrees of development. Crucially, endotherms provide lengthy parental care, including thermal and food provisioning—whereas ectotherms seldom do. These differences could be expected to manifest themselves in major differences between clades in quantitative reproductive traits. We review the reproductive characteristics, and the distributions of brood sizes, breeding frequencies, offspring sizes and their derivatives (yearly fecundity and biomass production rates) of the four major amniote clades (mammals, birds, turtles and squamates), and several major subclades (birds: Palaeognathae, Galloanserae, Neoaves; mammals: Metatheria and Eutheria). While there are differences between these clades in some of these traits, they generally show similar ranges, distribution shapes and central tendencies across birds, placental mammals and squamates. Marsupials and turtles, however, differ in having smaller offspring, a strategy which subsequently influences other traits.

Metal Organic Framework Based Catalytic Nanoreactors (CatNRs): Synthetic Challenges and Applications

Catalytic nanoreactors have become hugely important in the field of heterogeneous catalysis due to their intriguing catalytic activity and the stability of the nanocatalysts inside the protective shell. Metal-organic frameworks...

Research methodology in economics

Introduction. Some methodological provisions need to be modified according to the realities of existing practice and be verified according to the possibilities of their application in economic phenomena and processes study. Theoretical analysis of methodological principles, their comparison and generalization were used during investigation. The purpose of the paper is to study basic methodological prerequisites and principles in economic research. Results. Analyzing and summarizing the achievements of Nobel laureates, the methodological problems of limited rationality, information asymmetry and opportunistic behavior of economic agents are considered. Modern mainstream in economic research corresponds to binary paradigm of neoclassicism and neoinstitutionalism, which are based on two common elements of the “core”: methodological individualism and “economic man” conception (homo economicus). The focus of the enterprises on maximizing profitability, and households – on benefits, is an axiom of neoclassicism, which implies significant requirements for information quantity and quality. At the same time, rational choice is accompanied by situations of uncertainty and varying degrees of risk regarding such activities consequences. The advantages of the institutional direction as the closest to the real conditions of economic entities market activity are substantiated. A specific feature of neoinstitutional approach is modification of neoclassical paradigm due to preserving basic preconditions of its “core” and partial transformation of “protective shell” into more perfect, realistic principles. In economics, the most significant is methodological combination of “semi-strong” limited rationality with a “strong” form of opportunistic behavior. Conclusions. Thanks to introducing modified preconditions and methodological principles into neo-institutionalism, it became possible to improve the analysis of economics and to apply interdisciplinary research in combination with the approaches of other branches of science.