Effects of Inert Nanoparticles of High-Melting-Point Compositions on Grain Structure and Strength of Ni[3]Al Intermetallic Compounds

The paper represents experimental findings both in the area of effects of nanoparticles of inert high-melting-point TiN compounds on a Ni[3]Al intermetallic grain structure creation in the conditions of high temperature synthesis under pressure, and in the area of impact of grain structure modification on intermetallic compounds' strength factor temperature dependence. It was demonstrated that appending a stoichiometric composition of nanosized particles of high-melting-point inert chemical compounds (TiN) initiates a manyfold loss of average size of grain of Ni[3]Al intermetallic compounds, synthesized under pressure, as well as a sufficient intermetallic compounds' strength rise within a wide range of temperatures (up to 1 000 degree C). Electron-microscopic evaluations of a synthesized intermetallic structure with TiN nanoparticles, showed that, during the process of intermetallic polycrystalline structure creation from high temperature synthesis products melts, TiN nanoparticles are mainly spread throughout the boundaries and joints of grain structure, acting as stoppers of grain boundaries migration

Effects of Inert Nanoparticles of High-Melting-Point Compositions on Grain Structure and Strength of Ni[3]Al Intermetallic Compounds

The paper represents experimental findings both in the area of effects of nanoparticles of inert high-melting-point TiN compounds on a Ni[3]Al intermetallic grain structure creation in the conditions of high temperature synthesis under pressure, and in the area of impact of grain structure modification on intermetallic compounds' strength factor temperature dependence. It was demonstrated that appending a stoichiometric composition of nanosized particles of high-melting-point inert chemical compounds (TiN) initiates a manyfold loss of average size of grain of Ni[3]Al intermetallic compounds, synthesized under pressure, as well as a sufficient intermetallic compounds' strength rise within a wide range of temperatures (up to 1 000 degree C). Electron-microscopic evaluations of a synthesized intermetallic structure with TiN nanoparticles, showed that, during the process of intermetallic polycrystalline structure creation from high temperature synthesis products melts, TiN nanoparticles are mainly spread throughout the boundaries and joints of grain structure, acting as stoppers of grain boundaries migration

Development of a formalism of movable cellular automaton method for numerical modeling of fracture of heterogeneous elastic-plastic materials

A general approach to realization of models of elasticity, plasticity and fracture of heterogeneousmaterials within the framework of particle-based numerical methods is proposed in the paper. It is based onbuilding many-body forces of particle interaction, which provide response of particle ensemble correctlyconforming to the response (including elastic-plastic behavior and fracture) of simulated solids. Implementationof proposed approach within particle-based methods is demonstrated by the example of the movable cellularautomaton (MCA) method, which integrates the possibilities of particle-based discrete element method (DEM)and cellular automaton methods. Emergent advantages of the developed approach to formulation of manybodyinteraction are discussed. Main of them are its applicability to various realizations of the concept ofdiscrete elements and a possibility to realize various rheological models (including elastic-plastic or visco-elasticplastic)and models of fracture to study deformation and fracture of solid-phase materials and media.Capabilities of particle-based modeling of heterogeneous solids are demonstrated by the problem of simulationof deformation and fracture of particle-reinforced metal-ceramic composites

Finite Element Flow Simulations of the EUROLIFT DLR-F11 High Lift Configuration

This paper presents flow simulation results of the EUROLIFT DLR-F11 multi-element wing configuration, obtained with a highly scalable finite element solver, PHASTA. This work was accomplished as a part of the 2nd high lift prediction workshop. In-house meshes were constructed with increasing mesh density for analysis. A solution adaptive approach was used as an alternative and its effectiveness was studied by comparing its results with the ones obtained with other meshes. Comparisons between the numerical solution obtained with unsteady RANS turbulence model and available experimental results are provided for verification and discussion. Based on the observations, future direction for adaptive research and simulations with higher fidelity turbulence models is outlined.Comment: 52nd Aerospace Sciences Meetin

Synthesis of nitroxyl radical by direct nucleophilic functionalization of a C-H bond in the azadiene systems

Cyclic dinitrones underwent nucleophilic substitution of the hydrogen atom in the reaction with a paramagnetic carbanion, the lithium derivative of 4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-1-oxyl 3-oxide, to give polyfunctional nitronyl nitroxyls. © 2012 Springer Science+Business Media New York

Impact of High-Temperature, High-Pressure Synthesis Conditions on the Formation of the Grain Structure and Strength Properties of Intermetallic Ni[3]Al

The impact of the preliminary load on 3Ni+Al powder mixture and the impact of the duration of the delay in application of compacting pressure to synthesis product under the conditions of continuous heating of the mixture up to its self-ignition on the grain size and strength properties of the synthesized Ni[3]Al intermetallide material have been studied. The grain structure of the intermetallide synthesized under pressure was studied by means of metallography, transmission electron microscopy and EBSD analysis, with the dependence of ultimate tensile strength on the grain size in the synthesized intermetallide having been investigated at room temperature and at temperatures up to 1000°С. It is shown that an increase in the pressure preliminarily applied to the initial mixture compact results in reduced grain size of the final intermetallide, whereas an increase in pre-compaction time makes the grain size increased. A decrease in the grain size increases the ultimate tensile strength of the intermetallide. The maximum value of the ultimate tensile strength in the observed anomalous temperature dependence of this strength exhibits a shift by 200°С toward higher temperatures, and the ultimate strength of the synthesized intermetallide at 1000°С increases roughly two-fold

ЭФФЕКТ ВОЗДЕЙСТВИЯ 1,5-БИС(3,5-ДИМЕТИЛПИРАЗОЛ-1-ИЛ)-3-ОКСАПЕНТАН-ДИАЦЕТАТОМЕДИ НА ОБЩЕЕ СОСТОЯНИЕ ОРГАНИЗМА КРЫС В УСЛОВИЯХ ЭКСПЕРИМЕНТА

Многие производные пиразола проявляют разнообразные фармакологические свойства. Им характерны антиоксидантная, антивирусная активность, противовоспалительные, иммуномодулирующие свойства, а также антидепрессивный и противоопухолевый эффекты. Данная работа основана на результатах морфометрических показателей массы тела и печени и биохимического анализа крови здоровых взрослых самцов белых крыс после однократного и многократного внутрибрюшинного введения 1,5-бис(3,5-диметилпиразол-1-ил)-3-оксапентан-диацетатомеди, растворенного в свежеприготовленном физиологическом растворе (доза 12 мг / кг массы тела). Результаты исследования показали, что при введении препарата в организм крыс проявляются различные эффекты. Установлено, что исследуемое вещество имеет гипогликемический эффект, о чем свидетельствует снижение уровня глюкозы в крови и увеличение количества гликогена в печени. Антилиполитический его эффект подтверждается снижением уровня свободных жирных кислот в крови. Токсическое воздействие препарата проявляется повышением уровня печеночных ферментов аланин аминотрансферазы и аспартат аминотрансферазы, а также снижением уровня альбумина в сыворотке крови и уменьшением массы тела и печени. Эти эффекты проявляются и сохраняются только при многократном ежедневном применении этого препарата в течение 6 недель