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To explore freeway tunnel effects on ring road traffic flow, a two-lane traffic model is put forward. The model adopts lane-changing time to describe the net lane-changing rate, assuming that the time is approximately equal to the relaxation time of traffic flow, but infinite when the absolute value of difference of traffic density between the two lanes is lower than 1 veh/km, as it is hard for car drivers to perceive such a small difference. Based on the two-lane traffic model, a simulation platform is built to predict traffic flow on a two-lane freeway ring with a tunnel of 0.3 km length having a speed limit of 80 km/h, and free flow speeds on lane I and II equal to 120 and 100 km/h, respectively. The platform uses a third-order Runge–Kutta scheme to handle the time derivative term, and a fifth-order weighted essentially non-oscillatory scheme to calculate numerical flux. Simulation results show that the freeway tunnel can trigger traffic shock originating at the entrance when the coming flow density is beyond a traffic density threshold that is dependent on the off-ramp flow just upstream the tunnel. The occurrence of traffic shock leads to the mean travel time through the tunnel is almost a constant when the initial density normalized by jam density is less than 0.5. When initial density is above the density threshold, generally vehicles need more fuel consumption to run through the ring road in comparison with the case without tunnel. But the situation is just the opposite for larger normalized initial density such as 0.5.

The effect exerted on the chemical properties and structure of activated carbon by the mechanical treatment as a modification procedure was studied. Mechanochemical modification of carbon samples was performed in a roller–ring vibration mill for 5 to 30 min. Samples were studied by X-ray diffraction, IR spectroscopy, and low-temperature nitrogen adsorption. X-ray diffraction analysis shows that the supply of mechanical energy increases the extent of structural disordering of activated carbon, which is manifested in an increase in microstrains. The mechanical treatment for more than 5 min led to a decrease in the specific surface area of the samples with a simultaneous increase in the total pore volume. The mechanical treatment for 5 min and less led to an increase in the specific surface area and to a decrease in the pore volume. The results of potentiometric titration and Boehm titration show that the modification leads to an increase in the concentration of phenolic and carboxyl groups. It is concluded that mechanochemical modification of activated carbon in air leads to its intense oxidation resulting in formation of oxygen-containing groups and in their decomposition.

The acid-base properties of cobalt ferrite synthesized by the mechanochemical method with different ratios of the main components Fe2O3 : Co3O4 have been investigated using the temperature-programmed desorption of ammonia, IR spectroscopy using adsorbed pyridine with ammonia, and the Hammett indicator method. A comparison of the results for the total content of Lewis and Bronsted acid sites by three methods has shown that all three samples were quite similar, with a probability of 0.5%. The introduction of cobalt oxide into the composition of cobalt ferrite leads to an increase in the concentration of Bronsted and Lewis centers with a simultaneous increase in the number of strong basic centers determined by the temperature-programmed desorption of ammonia. The indicator method is the most informative method for a quantitative study of the acid-base properties of the cobalt ferrite surface, since it allows one to assess the concentration and strength of Lewis and Bronsted acid sites and basic sites.

A method for the determination of the total amounts and physical parameters of adsorbed individual hydrogen species on the surface and in the bulk of metal catalysts of liquid-phase hydrogenation reactions by simultaneous thermal analysis mass spectrometry was proposed. The adsorptions of reactive hydrogen on a skeletal nickel catalyst in an aqueous medium were estimated. The concentrations of metal-hydrogen complexes with different binding energies on the surface of the catalyst in the liquid phase were determined by a direct experimental method.

The environmental problems of the production of extraction phosphoric acid and the effect of fluorine on the human body are discussed in the article. The creation of the industry of phosphoric fertilizers on the basis of processing of fluorine-containing phosphate raw materials and fluorine-containing compounds, the development of their application require the study of environmental consequences arising from this, because fluorine is characterized by high mobility in the biological cycle of metabolism. For the purification of phosphoric acid from fluorine was used carbon adsorbents such as active charcoal brand BAU, natural graphite deposits Kyshtymsky, P514 soot, charcoal. Experiments on the purification was carried out on non-evaporated half-hydrated extraction phosphoric acid which was produced by joint stock company «Apatit» in Cherepovets city in Russia. The following analyses were carried out: IR-Fourier spectrometry, research of acid–base properties of carbon materials by potentiometric titration, potentiometric method of fluorine determination in extraction phosphoric acid. It is mentioned that the carbon black P514 is the most efficient adsorbent for purification of extraction phosphoric acid. The total number of functional groups on its surface is 0.62 mmol/g, the degree of purification from fluorine compounds is 94.8%.

A comparative analysis of the main types of greases and base oils for their manufacture that are used for lubricating mechanisms operating in space is performed. Their differences in terms of chemical composition, volatility, and operating temperature range are analyzed. The research results on the tribological properties of lubricating greases and on the effect of the base oil and additive types on their life are presented. The main techniques for testing the volatility, the lubricating ability, and the life of greases are reviewed.

By the reaction of nucleophilic substitution of bromine atom and the nitro group of 4-bromo-5- nitrophthalonitrile 4,5-diphenoxyphthalonitrile was obtained and on its basis new derivatives of octa-4,5- phenoxyphthalocyanine were synthesized soluble in water- and organic solvents. The spectral properties and thermodestruction of the products were investigated.

A method of synthesis of 4-(1H-benzotriazol-1-yl)-5-[(4-carboxyphenyl)oxy]- and -5-[(4-carboxyphenyl) sulfanyl]phthalonitriles starting with 4-bromo-5-nitrophthalonitriles was developed. The synthesized phthalonitriles were used to prepare cobalt tetra-4-(1H-benzotriazol-1-yl)-tetra-5-[(4-carboxyphenyl)oxy/sulfanyl]phthalocyanines. The spectral and catalytic properties of the resulting octasubstituted phthalocyanines were studied.

The paper is devoted to the search for more effective adsorbents for the defluorination of wet-process phosphoric acid, as well as methods for their synthesis. It was established that mechanochemical modification of activated carbon allows more complete removal of fluoride from the acid. Modification was carried out in a roller-ring vibrating mill. The original and modified samples were analyzed using such methods as scanning electron microscopy, low-temperature nitrogen adsorption/desorption, and potentiometric titration. It was revealed that the mechanical effect on activated carbon for 5 minutes leads to an increase in the specific surface by 11.6%, the concentration of carboxyl and phenol groups by 59.6 and 12.8%, respectively. This led to an increase in the efficiency of phosphoric acid defluorination. When using a modified sample, fluorine content decreased from 2.06 to 1.73 wt. %. The positive effect of mechanical action is due to the active oxidation of activated carbon, that is, an increase in the concentration of functional groups containing a hydroxyl fragment that is replaced by fluorine during the purification process.

The suitability of the methods of simultaneous thermal analysis combined with Fourier-transform IR spectroscopy for express investigation and selection of catalysts and sorbents has been demonstrated. Through case studies on reacting aqueous ethanol with carbon and carbon fiber it has been shown that, in the 20–100°C temperature range, ethanol is adsorbed on the carbon material surface, and in the 100–200°C range, it is desorbed. The revealed change in the amount of the ethanol desorbed and the carbon dioxide evolution data indicate that, along with ethanol sorption, oxidation of the adsorbed ethanol occurs.

For production of binding building materials in Russia and worldwide, used a variety of calcium-containing natural raw material: calcium carbonates, aragonite (CaCO3); sulfates-gypsum (CaSO4∙2H2O,CaSO4); oxides and hydroxides (bauxite glinozemservice); perforate-apatites and phosphates (Ca5∙(PO4)3∙F). The article discusses the need for air-conditioning of phosphogypsum to ensure that he was suitable without restrictions for processing into high-quality gypsum binders.

In this paper, the results of studying the efficiency of an SP-6 M switch motor have been presented. The friction clutch plays an important role during the transmission of torque from a motor to an actuator. To study a motor switch, a test rig was developed in order to determine the necessary force to move switchblades depending on the pressing force of the friction clutch. The tribological properties of the friction disk materials have been investigated using a specially designed test machine.

The results of the tribological properties studies of composite materials at cryogenic temperatures are presented in the present paper. Test equipment has been developed, friction and wear tests have been carried out at a temperature of T = - 196 °C. The test results showed a significant dependence of the composite material wear rate on the load.

This paper presents the methodology and test results of rolling bearings of low-flow electric pump units used to ensure circulation of the thermal liquid in the active thermal control system of spacecraft. A multi-position stand has been developed for testing bearings within 40 days in a thermal liquid at a speed of 6000 rpm with the possibility of registering the separator rate speed. As a performance criterion, the clearance in the bearing is used. The conditions of the onset of pitting are investigated.

This article presents a methodology for the study of the relative lifetime of lubricating greases operating in rolling friction. An experimental assembly is described for testing lubricating greases in order to determine the friction coefficient and relative resource. A criterion for assessing the relative resource of lubricating greases has been proposed. The test results of the proposed method were obtained and presented.

This research paper presents the results of studies of the tribological properties of materials manufactured using the “KARBUL” technology, modified with powders of various compositions. The tests were carried out according to the “disk-disk” friction pair on a modern friction machine SMT-1. The structure and wear mechanism of materials manufactured using the Karbul technology have been investigated.

The kinetics of non-isothermal decomposition of ZnO/Al(OH)3 and Zn4CO3(OH)6·H2O/Al(OH)3 has been studied both for the starting mixtures and for mixtures after co-grinding. The process has been controlled by X-ray diffraction, scanning electron microscopy, thermogravimetry and differential scanning calorimetry under air atmosphere (the heating rates were 5, 10 and 15 °C min−1). The activation energy was calculated using the Friedman analysis and Ozawa–Flynn–Wall analysis. It was shown that both methods gave similar results. It was found that the dehydration activation energy of gibbsite to boehmite in the mixture with ZnO gradually is decreased from 150–170 to 100 kJ mol−1. At the final stage (conversion degree was more than 0.9), the dehydration process converted from kinetic mode into the diffusion mode (the activation energy was 50–70 kJ mol−1). It was established that the activation energy of Zn4CO3(OH)6·H2O/Al(OH)3 decomposition at a conversion degree

Friedman and Flynn-Wall-Ozava methods were used to study the nonisothermal decomposition kinetics of the Zn4CO3(OH)6/Al(OH)3 system. It was shown that thermolysis processes occur in the kinetic mode and, after a degree of decomposition exceeding 0.9 is reached, pass under diffusion control. It was found that, upon co-grinding of the components, the apparent activation energy increases as compared with the values for the starting mixture.

X-ray phase analysis, thermogravimetry, and volumometry were used to study the mechanochemical synthesis of zinc oxide. The conversion of metallic zinc was calculated in relation to the time and method of mechanical activation and to the oxidizing medium used. The most optimal conditions of oxidation of metallic zinc were determined.

An attempt is made to summarize studies of the erosion-corrosion wear fracture of materials, which proceeds by a complex mutually determining mechanism. Parts of submersible pumps and pipelines of nuclear power plants, as well as members of shutoff gate valves, which are subjected to this mode of fracture are considered. Basic methods and test equipment used in the experimental studies are described.

For the first time, a complex investigation of bottom sediments is made for Glubokoe Lake, one of the best investigated in Russia in the aspect of long-term (over 100 years) biomonitoring. The study program comprised nonbiological paleolimnological and biological approaches. In spite of extensive information available on the present-day flora and fauna, the origin and history of Glubokoe Lake have still not been investigated. The present study revealed the history of development of the lake. This article contains a concise description of the results of this study.

Possibility of synthesizing aluminum-zinc-copper catalysts by mechanochemical activation of metallic copper and zinc with ammonium carbonate, followed by introduction of γ-Al2O3 and promoter additives (potassium, rubidium, and cesium carbonates), hydrothermal treatment, and calcination is demonstrated. The effect of the promoter additives and preparation conditions was studied. The activity and selectivity of the samples in the reaction of steam conversion of CO was examined. The composition of by-products formed in the course of a test reaction was determined.

The X-ray phase analysis and X-ray diffraction, as well as IR and Mossbauer spectroscopic techniques were employed to study mechanochemical oxidation of iron metal powder with oxygen. The phase composition of the products of mechanochemical activation of iron in a vibrating mill was determined. The extent of oxidation of iron was examined in relation to the particle-size distribution of the starting iron powder.

The effect of intense mechanical actions on the rate of oxidation of copper metal in a steam-air-ammonia-carbon dioxide gas atmosphere was studied. Based on data on changes in the particle size of copper metal and the rate of its oxidation, the effect of the degree of gas mixture saturation with the components on the efficiency of mechanochemical activation was considered. The effect of the gas mixture composition on the chemical composition of oxidation products was demonstrated.

The purpose of the presented work is to increase the lifetime of space mechanisms bearings. The authors reviewed the studies of the bearings and linear mechanisms operating in air and in vacuum. A testing equipment is developed to assess the lubricity and lifetime of greases in the air. Criteria for the evaluation of relative lifetime are defined. Four types of space greases are tested.

The ways for the development of refined phosphoric acid (RPA) production were shown with respect to changing the structure of the world production and consumption of technical and food phosphoric acid. The analysis of RPA production methods evidenced the major problem related to purification from such components as fluorine compounds and soluble complex fluorine compounds. The necessary product quality was achieved by the application of universal complex refinement methods with wet-process phosphoric acid (EPA) using coal adsorbents. A higher efficiency of the proposed RPA production method was achieved by combining the stages of fluorine compounds elimination and catalytic adsorption refinement.

The effect of additions of nanostructured tungsten carbide powder into a sinter mixture with compaction of sintered hard alloy VK8 on its tribological properties has been studied. Physicomechanical properties of the material obtained have been estimated. The produced hard alloy shows elevated wear resistance to abrasive wearing.

A number of styrylquinoline chromophores with carboxyl groups have been prepared through the interaction of 2-methylcinchonic acid with aromatic aldehydes of various chemical structures. The copolymer of glycidyl methacrylate and methyl methacrylate carrying side epoxide groups has been synthesized, and the chemical modification of the copolymer with the above chromophores has been performed. The thermal, spectral, and nonlinear optical properties of the chromophores and modified polymers have been studied.

The most significant results of the theory and practice of mixing in fluid media, including those obtained in the last decade, are analyzed. Some important issues of further development of theoretical and applied problems are formulated.