No 4 (2016)

For the efficient operation of worm gear cutters (WGC), it is necessary to know their initial and final adjustments against the processed wheel workpiece. It is shown, that at equal initial data, the values of initial and final adjustments of WGC are different in different information sources, and the concepts of initial and final adjustments of WGC define ambiguously the relative position of a hob and a wheel workpiece. To understand definitely what part of WGC is spoken about, it is necessary to use the concepts of minimum lengths of entry and exit parts of WGC instead of the concepts of initial and final WGC adjustments. The shortening of the entry and exit parts of hobs to be less than the minimum admissible values is impossible due to the creation of defects of gear wheels along the teeth profile. If the lengths of entry and (or) exit parts of hobs are more than the minimum admissible values, the cutting power resource of hobs will not be used to a full degree, i.e. possible maximal period of their durability will not be ensured. Using the method of computer simulation modeling of the kinematics of the process of hobbing by the WGC, when hobbing up and down with the axial feed, the authors defined the minimum lengths of WGC entry and exit parts when hobbing helical wheels with the module of 3 mm, teeth inclination angle of 30° and the teeth number equal to 20, 45 and 90 pieces. The authors proved experimentally the reliability of the results gained by the computer simulating modeling and their essential difference from the data given in reference books. The study identified the essential influence of the direction of axial feed (up or down) on minimum lengths of WGC entry and exit parts when hobbing helical wheels.

Brazing in zinc vapor allows not only to prevent zinc evaporation out of brass brazing alloys and to use furnace heating without limitations but also to eliminate the flux application when brazing carbon steels even if before heating the container for brazing has the atmospheric air (brazing in modified air environment). Brazing in a container with a filling-sealed stopper with the carburizer superinduction to the container and in the filling composition is currently the easiest and the most reliable option for brazing in zinc vapors. Such technology does not require the application of complex specialized equipment. Brass brazing alloys can be produced from copper billet by alloying it with zinc from a vapor phase. The work was carried out in relation to this variant. The formation and quality of brazed joints when brazing in a container, in particular in zinc vapors, is the result of a number of closely related physical and chemical processes. The construction of the analytical model of these processes combination is problematic at present. The challenge was solved by the method of mathematical design of experiments. The authors carried out the complete factorial experiment and then, using the composite design, they produced the second-order equations (including the coefficients of pair and triple interaction) describing pretty exactly the dependencies of breaking stress, strength, gaps filling factor and the ratio of brazed joints defects on the main technology factors (temperature and exposure time, the amount of zinc and the amount of carburizer). Two methods of brazing modes optimization were proposed and used. When selecting the modes, the most important quality indicators for a specific product should be considered.

The authors suggest a mathematical description of the process of ion-exchange purification of solutions from heavy metal ions using the continuous pulsed column with KRIZM perforated trays. While developing mathematical description, the following assumptions are used: the ionite is monodisperse and has a spherical shape, the ion exchange equilibrium is described by Nikolsky equation, the velocity of the process is limited by both internal and external diffusion, the ionite and the solution in the device move in opposite directions, the solution moves with the effects of longitudinal and radial mixing. The two-parameter diffusion model is used to describe the solution movement in the device. To solve the task, the authors applied the interval-iterative approach based on a reasonable combination of analytical and numerical methods of the theory of mass-exchanging processes. The kinetic and hydrodynamic parameters of the process are constants on each tray; the equilibrium equation of Nikolsky is replaced with the equation of the tangent to the nonlinear equilibrium dependence. The obtained equations allow calculating the distribution of the solution concentration throughout the height and the radius of the ionite bed on the tray. The sorbate concentrations in the solution and ionite found on one tray become the input data for the calculation of the overlying tray. The general picture of the ion exchange process for the whole device is determined by the successive finding of solutions for all trays. The authors determined the validity of the mathematical model on the example of the waste water purification from nickel ions on the KU-2-8 cationite in the continuous pulsed column. The deviation of the calculated results from the experimental data does not exceed 10 %. The elaborated mathematical model is recommended for practical application.

Deep choke modes that include the no-load conditions are the most long lasting while operating a car in the city environment. However, the efficiency of work process at the deep choke modes remain low due to high intake depression and the large proportion of residual gases. The paper covers the evaluation of the hydrogen influence on the irregularity of compressed natural gas (CNG) combustion behavior in the engine at the no-load conditions through the assessment of change of the polytropic index as the parameter displaying the direction and the intensity of heat-exchange processes. The paper considers the feasibility to determine the quantity of residual gases and their proportion in working mixture. Carried out experimental study of the hydrogen influence on the cycles irregularity at the idle modes of the VAZ-2111 engine showed the decrease of variation of maximum pressure in the engine cylinder when increasing the proportion of hydrogen in gas fuel from 0 up to 6 %. The authors carried out the detailed study of hydrogen influence on the cycles’ irregularity for three stoichiometric ratios of the CNG mixture with the hydrogen proportion of 0, 4 and 6 %, three the most representative successive cycles displaying the irregularity of engine operation were selected for each of them. The study of the polytropic index on the selected cycles allowed determining the quantity of the residual gases and their proportion in working mixture and showed the significant influence of quality of combustion in the previous cycle on the thermodynamic processes behavior within the compression stroke and the combustion process efficiency in the next cycle. The obtained results allow evaluating the influence of hydrogen addition on the CNG combustion process and concluding that the addition of 6 % hydrogen allows better initiating the ignition process, thereby, preventing the ignition failures and decreases significantly the number of incomplete combustion cycles increasing the efficiency of working process at the idle modes.

The phenomenon of compounding, the reasons for writing words as one solid word or hyphenated, functional activity of compound nouns with evaluative or associative components, structural types of compound words, and other issues attract the attention of scientists-linguists. Currently, the Russian discourse fixes high frequency of the tzar-derivatives – words with an indeclinable evaluative component tzar- (Tzar-product, Tzar-bag, Tzar-tree, Tzar-girl, etc.). It is caused by the tendency to analyze and to the fact that tzar-derivatives represent the Russian linguistic picture of the world, which reflects a human holistic view of the surrounding reality. Increasing the number of lexical units in the vocabulary, the activity of tzar-derivatives and the need for their systematization determine the relevance of the study. The concept of “lexical set” is serving as a unit of systematization. The paper reveals distinctive features of a lexical set as a kind of semantic field. It emphasizes the fact that topical classification (extra-linguistic) is associated with the classification into lexical-semantic groups (linguistic). The classification of tzar-derivatives is defined, the following five lexical sets are described: “A person – non-person”, “Unique items”, “Nature and its components”, “Spiritual sphere and its components”, “Nominations in advertising”, each which includes several subgroups. The most extensive lexical set is revealed. It is proved that, as a result of transnomination, tzar-derivatives can be produced within a lexical set “Nominations in advertising”. The author emphasizes that the units of the four groups: “A person – non-person”, “Unique items”, “Nature and its components”, “Spiritual sphere and its components” are characterized by contextual synonymy. To achieve the goals of the work, a set of complementary research methods was used.

The paper presents the comparative analysis of cognitive aspects of sight interpretation in order to identify special translational skills required to perform this type of activity. The relevance of the study is caused by the fact that the sight interpretation is studied by Russian and foreign translatology linguists less than the other types of translation practice (interpreting and translating). The subject of the study is the identification and the description of skills peculiar for sight interpretation only, and unusual for translation and interpreting. The paper pays attention to the psychological activities when translating at sight and compares them with the psychological processes taking place when translating and interpreting. Besides that, the paper analyses the number of challenges the translators and interpreters unprepared to make sight interpretation meet. The author makes the conclusion that the sight interpretation requires special training and teaching of two groups of translational skills: reading and understanding original texts; text production in the language of translation. The paper analyses key difficulties the interpreters and translators meet while performing sight interpretation that can be eliminated with the help of training. The author makes the conclusion that the sight interpretation supposes the mastering of special skills different from that required to perform translation or interpretation. 

The paper focuses on the differentiation of the middle class. The authors study the main approaches used to define the middle class, based on foreign and domestic theory; present various views on the social structure of the society, and criteria for systematization from the point of view of their evolution and continuity. A brief overview presents the formation of the middle class from ancient times to the present. The paper describes classical and modern criteria for determination of the middle class, its main components in modern society, emphasizes its functional role – to stabilize and facilitate social progress.

The authors analyze the features of the Russian middle class formation. When determining the middle class, the scientists take into account four criteria: education is not lower than secondary; monthly income per capita is median or higher in the Russian Federation and each region; nonphysical nature of work; self-identification is not below 4 or 5 on a 10-point scale.

The paper provides the results of applied research in the Republic of Tatarstan and specifies the approaches to the definition of the middle class on the regional level. As a part of these studies, there is a division into the proper middle class and middle-class core. The middle class is understood as respondents with the “monthly income” as a key criterion, and the middle-class core is distinguished according to such criteria as: education, self-identification, type of work and trust in the government. As a result, the amount of middle class in Russia according to the experts varies from 3 % (“the ideal middle class”) to 30–60 % (“prospective middle class”).