Influence of the surface layer characteristics on the regularities of the cutting process

The article considers the influence of the surface layer characteristics on the regularities of the cutting process and the formation of the quality of the surface machined. This effect has been confirmed by the study results of the combined cutting method with advanced plastic deformation (APD). The work estimates the impact of the change in the surface layer properties on the forces and temperature of cutting, stability of the chip formation and quality parameters of the surface machined

Use of electrochemical impedance spectroscopy to assess the stability of the anion exchange membrane MA-41, modified by poly-N,N-diallylmorpholine bromide in overlimiting current modes

The paper presents the results of studying the electrochemical characteristics and long-term stability of MA-41 membranes on the surface of which poly-N,N-diallylmorpholinium bromide was applied. The deposition of a polyelectrolyte on the membrane surface leads to an increase in the limiting current from 0.8 to 1.1 mA/cm2. The comparison of the experimental and theoretically calculated values of the limiting current density allows us to conclude that the modification of the membrane surface by poly-N,N-diallylmorpholinium bromide does not lead to the formation of a continuous polyelectrolyte film on the surface, but its fixation occurs due to the sorption of macromolecules on the surface of the ion-exchanger particles. To quantify the rate of the water dissociation reaction at the membrane/solution interface, the method of electrochemical impedance was used, which makes it possible to compare the rate constants of the water dissociation reaction for different membranes, assuming that the reaction is described by the Gericher impedance. It is shown that modification of the MA-41 membrane surface leads to a decrease in the rate of the water dissociation reaction in the current range i = 1.5–4ilim by a factor of 2–6. The reduction in water dissociation reaction rate is attributed to the substitution of catalytically active secondary and tertiary amino groups in the surface layer of the pristine membrane by stable heterocyclic ammonium bases of poly-N,N-diallylmorpholinium. The study of the long-term stability of the resulting membrane showed that when the membrane is polarized with a current equal to  twice the limiting current, the desorption of the modifier occurs within 25 h, and the properties of the membrane become close to those of the unmodified MA-41 membrane. It was shown that the electrochemical impedance method can be used as a very sensitive method for studying the long-term stability of ion-exchange membranes

Mathematical model of stacked one-sided arrangement of the burners

Paper is aimed at computer simulation of the turbulent methane-air combustion in upgraded U-shaped boiler unit. To reduce the temperature in the flame and hence NOx release every burner output was reduced, but the number of the burners was increased. The subject of studying: complex of characteristics with space-time fields in the upgraded steam boiler E-370 with natural circulation. The flare structure, temperature and concentrations were determined computationally

Study of the Process e+ e- --> omega pi0 --> pi0 pi0 gamma in c.m. Energy Range 920--1380 MeV at CMD-2

The cross section of the process e+ e- --> omega pi0 --> pi0 pi0 gamma has been measured in the c.m. energy range 920-1380 MeV with the CMD-2 detector. Its energy dependence is well described by the interference of the rho(770) and rho'(1450) mesons decaying to omega pi0. Upper limits for the cross sections of the direct processes e+ e- --> pi0 pi0 gamma, eta pi0 gamma have been set.Comment: Accepted for publication in PL

Influence of the surface layer characteristics on the regularities of the cutting process

The article considers the influence of the surface layer characteristics on the regularities of the cutting process and the formation of the quality of the surface machined. This effect has been confirmed by the study results of the combined cutting method with advanced plastic deformation (APD). The work estimates the impact of the change in the surface layer properties on the forces and temperature of cutting, stability of the chip formation and quality parameters of the surface machined

Obtaining of hydroxylated fullerenes Y@C82OX(OH)Y, Y2@C82OX(OH)Y, Y2C2@C82OX(OH)Y and electrophysical characteristic of composite film based thereon

The article presents, for the first time, the results of the research on composite film obtained from hydroxylated endohedral metallofullerenes (EMF) Y@C82, Y2@C82, with Y2C2@C82 and highest fullerenes as dopant. The composite film has been established to have electric conductivity and to be a ferroelectric with the value of residual polarization of ~0.75 mkC/cm2. The impedance spectroscopy of this sample allowed us to determine dispersion of dielectric permittivity and conductivity in the range of frequencies of 0.5Hz–100MHz. It is stated that the value of the high-frequency dielectric permittivity of films is e' = 2.8. However, with reduction in the electric field frequency, real and imaginary parts of e increase to values ~10^4–10^5. Such increase in dielectric permittivity is connected with increase in polarizing caused by accumulation of mobile electric charges (electrons of ions, protons) on boundaries of the structural defects of a film, which are divided by thin dielectric interlayers. The film is solid electrolyte with the ionic conductivity of ~5*10^(-7) S/cm

The Concept of Recognition of Air Targets in the Aviation Radar Complex

Предложен вариант концепции всестороннего распознавания воздушных целей в авиационном радиолокационном комплексе истребителя, определены перечни решений летчика-истребителя, уровни оптимизации наведения управляемых ракет и элементы искусственного интеллекта, основанные на распознавании воздушных целейThe version of the concept of comprehensive recognition of air targets in an aviation radar complex of the fighter is offered, the lists of decisions of the pilot of the fighter, levels of optimiza-tion of guidance of guided missiles and elements of artificial intelligence based on recognition of air targets are define

Synthesis of Optimum Algorithms of Aircraft Guidance at the Group Aerial Target

В статье в рамках теории оптимального управления в пространстве состояний, при подходах в постановке Лётова-Калмана и на основе обратных задач динамики синтезированы оптимальные по критерию минимума квадратичного локального функционала качества алгоритмы наведения истребителя и ракеты класса «воздух-воздух» на групповую воздушную цель. Данные алгоритмы наведения совместно с минимальным промахом дополнительно обеспечивают в бортовых радиолокационных станциях соответствующих летательных аппаратов требуемые условия для радиолокационного наблюдения отраженных от групповой воздушной цели сигналов в интересах разрешения элементов групповой воздушной цели по доплеровской частоте на основе эффекта радиолокационного синтезирования апертуры антенны и распознавания типа атакуемой ВЦ на основе эффекта вторичной модуляцииIn the article, in the framework of optimal control theory in state space, while approaches in the formulation of the Letov-Kalman’s and on the basis of inverse dynamics problems, the synthesized optimal by the criterion of minimum quadratic local functional quality of the algorithms targeting the fighter and the missiles “air-to-air” on-air group goal. These algorithms guidance together with minimal penalties additionally provide onboard radar stations of aircrafts of appropriate conditions required for the radar reflected from an aerial target group signals in the interests of resolution of the elements of group air targets on a Doppler frequency based on the effect of radar synthetic aperture antenna and recognition of the attacked VTS based on the effect the secondary modulatio

Influence of TiC Addition on Corrosion and Tribocorrosion Resistance of Cr₂Ti-NiAl Electrospark Coatings

Marine and coastal infrastructures usually suffer from synergetic effect of corrosion and wear known as tribocorrosion, which imposes strict requirements on the structural materials used. To overcome this problem, novel composite wear- and corrosion-resistant xTiC-Fe-CrTiNiAl coatings with different TiC content were successfully developed. The coatings were obtained by the original technology of electrospark deposition in a vacuum using xTiC-Cr2Ti-NiAl (x = 0, 25, 50, 75%) electrodes. The structure and morphology of the coatings were studied in detail by XRD, SEM, and TEM. The effect of TiC content on the tribocorrosion behavior of the coatings was estimated using tribological and electrochemical (under stationary and wear conditions) experiments, as well as impact testing, in artificial seawater. The TiC-free Fe-Cr2Ti-NiAl coating revealed a defective inhomogeneous structure with transverse and longitudinal cracks. Introduction of TiC allowed us to obtain coatings with a dense structure without visible defects and with uniformly distributed carbide grains. The TiC-containing coatings were characterized by a hardness and elastic modulus of up to 10.3 and 158 GPa, respectively. Formation of a composite structure with a heavily alloyed corrosion-resistant matrix based on α-(Fe,Cr) solid solution and uniformly distributed TiC grains led to a significant increase in resistance to stationary corrosion and tribocorrosion in artificial seawater. The best 75TiC-Fe-CrTiNiAl coating demonstrated the lowest corrosion current density values both under stationary (0.03 μA/cm2) and friction conditions (0.8 μA/cm2), and was characterized by both a 2-2.5 times lower wear rate (4 × 10−6 mm3/Nm) compared to AISI 420S steel and 25TiC-Fe-CrTiNiAl and a high fracture toughness

The Concept of Recognition of Air Targets in the Aviation Radar Complex

Предложен вариант концепции всестороннего распознавания воздушных целей в авиационном радиолокационном комплексе истребителя, определены перечни решений летчика-истребителя, уровни оптимизации наведения управляемых ракет и элементы искусственного интеллекта, основанные на распознавании воздушных целейThe version of the concept of comprehensive recognition of air targets in an aviation radar complex of the fighter is offered, the lists of decisions of the pilot of the fighter, levels of optimiza-tion of guidance of guided missiles and elements of artificial intelligence based on recognition of air targets are define