Legitimacy of the narrow-channel approximation for the study of flames propagating between two closely-spaced parallel plates

International audienc

Numerical study of the propagation of lean hydrogen-air flames in Hele-Shaw cells

International audienc

Thermodynamic aspects of materials' hardness: prediction of novel superhard high-pressure phases

In the present work we have proposed the method that allows one to easily estimate hardness and bulk modulus of known or hypothetical solid phases from the data on Gibbs energy of atomization of the elements and corresponding covalent radii. It has been shown that hardness and bulk moduli of compounds strongly correlate with their thermodynamic and structural properties. The proposed method may be used for a large number of compounds with various types of chemical bonding and structures; moreover, the temperature dependence of hardness may be calculated, that has been performed for diamond and cubic boron nitride. The correctness of this approach has been shown for the recently synthesized superhard diamond-like BC5. It has been predicted that the hypothetical forms of B2O3, diamond-like boron, BCx and COx, which could be synthesized at high pressures and temperatures, should have extreme hardness

Quality control indicators of soil ridges at sowing cultivated crops

© 2016,International Journal of Pharmacy and Technology. All rights reserved.The initial component of any cultivated crops technology is high-quality preparation of a field in order to create proper conditions for the subsequent seed placement,plant root system’s growth and development stimulation. At the same time,any mechanical treatment should not disrupt the optimal soil structure; it should preserve the soil fertility,protect against erosion processes and maintain moisture to the greatest possible extent. Traditional technologies of growing cultivated crops on a flat field surface have been and remain the most widespread. However,the studies have found that the most promising is the ridge technology. A ridger seeder is developed for implementation of the ridge technology; the ridger seeder’s application allows to cost effectively perform presowing cultivation in just one pass,after sowing the seeds to form a soil mound over a stitch of sown seeds,to compact such soil mound on three sides and finally form a soil ridge of a required dimension and density. The tool’s flat disk and concave disks of the ridger seeder’s ridge forming roller have substantiated approach angles. It has been revealed that structural and operating parameters of the tools with flat discs and the ridge forming roller,as well as physical and mechanical properties of the soil affect the process of forming the soil ridges of required dimension and density at seeding any cultivated crops

The essential characteristic of safety as a category of right

© 2016 Minzhanov et al.The relevance of the study is conditioned by the reassessment of the value of security as the basis for sustainable development of civil legal relations, ensuring the protection of the vital interests of the individual, society and state, as well as the preservation of civil peace, political and social stability in society. The purpose of the article is to give the safety’s essential characteristics as the civil law category. The leading methods are comparative-historical and comparative-legal. The empirical base of the research is the normative legal acts of the Russian Federation on security. Core findings include: historical stages in the understanding process of security’s essence are identified (antique, Christian, Reformation, Enlightenment, classical, neo-classical); Security’s essence is disclosed as the state of absence of danger and versatile process for protection of the vital interests of the individual, society and state from internal and external threats; the basic safety features are revealed (generality, comprehensiveness, universality, multi-functionality); the basic directions of the civil right safety regulation are distinguished. This study provides important findings. Firstly, security’s civil right regulation provides the legal protection of the vital interests of the rights’ entities in connection with the entry into the sphere of legal relations. Second, it is the basis to confront the external and internal threats to the vital interests of the individual, society and the state by legal tools. Third, it creates conditions for strengthening of the inviolability of state-legal system and order, evolution of right and the state to the social ideals. The paper Submissions can be useful for those who are engaged in legislative activities, legal practice, teachers of legal disciplines

Five types of blow-up in a semilinear fourth-order reaction-diffusion equation: an analytic-numerical approach

Five types of blow-up patterns that can occur for the 4th-order semilinear parabolic equation of reaction-diffusion type u_t= -\Delta^2 u + |u|^{p-1} u \quad {in} \quad \ren \times (0,T), p>1, \quad \lim_{t \to T^-}\sup_{x \in \ren} |u(x,t)|= +\iy, are discussed. For the semilinear heat equation $u_t= \Delta u+ u^p$, various blow-up patterns were under scrutiny since 1980s, while the case of higher-order diffusion was studied much less, regardless a wide range of its application.Comment: 41 pages, 27 figure

Migraine pharmacology and brain ischemia

The aim of this review article was to analyze in details the mechanism of drugs’ effects in the treatment and prevention of a migraine attack, as well as to discuss the hypotheses of migraine pathogenesi

Femtosecond and Ultraviolet Laser Irradiation of Graphite-Like Hexagonal Boron Nitride

Effect of the femtosecond and nanosecond UV laser irradiation (below the ablation threshold) of graphite-like hexagonal boron nitride (hBN) has been studied. Experiments were carried out with the compacted powder under high vacuum at room temperature using excimer KrF laser (248 nm). In the nanosecond operation mode, the laser-induced fluorescence spectra are found strongly modified depending on the integrated doze, which is attributed to a progressive enrichment of the surface layer by elemental boron. A slow sample recovery after the laser irradiation has been observed. On the other hand, in the femtosecond mode the fluorescence spectra depend on the laser fluence, and the changes are reversible: low energy fluorescence spectra are restored immediately when the laser energy decreases. This effect can be explained by a material bleaching, which favors a bulk centers emission. The ablation threshold has been determined as 78 mJ/cm2 in the femtosecond laser operational mode