Vol 14

In the given article are discussed the results of the investigations and elaborating of the studies of character of radioactivity of sedimentary deposits of dicteenomous schists in Leningrad district. Here is treated also a theorie of genesis of radioactivity of dicteenomous schists. It was stated: a) Measure of dicteenomous schists differs from the other sedimentary rocks by the higher degree of radioactivity. b) Distribution of the radioactive substances in the shale measure is not uniform in the vertical cut of measure as well as in the direction of the strike. c) Thickness of the slices, containing the radioactive substance in different sections, varies considerably and reaches, as to the results of approbation, tens of centimeters. There are also some others results deducted.

The initial data for calculating the starting resistances are the following quantities: 1.Power and type of the drive motor; for the latter, the following must be obtained from catalogues: a) the ratio of the breakdown (maximum) torque to the rated torque; b) the rated rotor voltage; c) the rated rotor current; d) the efficiency of the motor; e) the synchronous and rated rotational speeds of the motor; 2. Calculated values of the starting torque; 3. Values of the static resistance torques corresponding to the starting period; 4. Number of steps of the rotor rheostat; 5. The starting period t1 and the entire period of the working cycle T, including the pause θ, in accordance with the given speed diagram (Fig. 1). The basis for calculating the starting resistances should be the mechanical characteristics of the motors, which must be constructed in advance (Fig. 2). In this context, one very important condition must be noted: not every motor of a given power rating will be able to meet the required starting conditions with a predetermined number of steps in the starting rheostat circuit, because the necessary range of variation of the starting torque cannot be maintained for just any magnitude of the motor's breakdown torque. To finally determine the individual steps of the rheostat, it is necessary first to determine the required operating time for each step, i.e., the duration during which one step is energized, as well as the magnitude of this current.

The article contains the calculation of the tables necessary for the construction of helical surfaces z=aφ+f(r)z=aφ+f(r), which are encountered in the theory of the spiral separator. (See the work of M. I. Akimoff, "Motion of a heavy point on a helix located on a frosted surface" in the Annals of the Mining Institute in Leningrad, Vol. 10, Issue 1 (1936), pp. 11 and 21, Vol. 12, Issue 3 (1939), pp. 4, 5, 38 and 39. See also the article by V. A. Egonnoff, "On the theory of the spiral separator" in the same scientific publications, Vol. 10, Issue 1, pp. 23–30.)

The problem of mathematical physics considered in this work is of great importance in mining, specifically in matters of shaft hoisting, and requires further development. Previously, the function e(s), which characterizes the law of variation of relative elongation for the part of the rope wound onto the drum, was considered arbitrarily assigned. Due to this arbitrary assignment, the elements of the aforementioned part of the rope, when passing through position C, undergo an impact at the moment they are incorporated into the vertical part BC of the rope, so that the relative elongation and velocity of these elements do not, generally speaking, coincide with the relative elongation and velocity of the part BC of the rope at point C, respectively. Note here that the values of the velocities differ from each other by a small amount of the order of relative elongation (see below). The problems of lowering and raising a load lead, generally speaking, to different forms of the second boundary condition. The coincidence of these forms occurs only in one special case, which requires a specific assignment of the function e(s). Finally, in conclusion, we examine as an example the nature of elastic deformations of the rope for the initial period of drum rotation (see the article).

The author of the given work on the basis of his own study of the frozen ground in the district of Vorkutskii mine and on the generalization of the literary materials treating this question gives a general understanding of development of a frozen ground process for the whole European North. It was stated by him, that degradation process of the frozen ground, which is clearly expressed in the South part of the place of its development, decreases gradually in the northern direction, and then comes over to the inversely process — advancing. Beside this, here is given an analysis of possibility of development of the process of degradation of frozen ground from the site of the North frozen Ocean, i. e. in the North-South direction. The author on the basis of concrete exemples gives the understanding of microdynamic of frozen ground stating by this the character of the local changes of dynamic of frozen ground process from such exterior factors as elements of geomorphology, hydrogeology, geobotany etc. All these questions are discussed by the author in the aspect of the practical using them for the economical development of the given region.

This article examines the issues of determining the error of analogies when calculating the volume of a deposit or the quantity of useful minerals based on drilling results with a regular grid of boreholes. The volume of the deposit or the quantity of ore calculated from drilling results depends on the exploration grid (the distribution of boreholes) or on the position of the starting borehole point. Here, a distinction must be made between the real error and the limiting error of analogy. The real error, like the volume, depends on the position of the starting borehole and therefore cannot be evaluated. The limiting error, however, does not depend on the starting borehole point and is determined both by the variability of the deposit indicator and by the distance between boreholes. For this reason, the limiting error can in principle be assessed from the drilling results. To this end, the article provides a table of limiting error estimates as functions of the exploration indicator. The exploration error is expressed as the ratio of the degree of variability to the relative density of the exploration boreholes. The degree of variability, in turn, can be calculated from the average value of the second differences of the deposit indicators and the arithmetic mean. The article also presents a new formula for calculating the deposit quantity based on the sum of the indicators measured in individual boreholes. The presented formula has a small analogy error compared to other formulas and methods for calculating the quantity of useful minerals. Using this formula and the described method for estimating the limiting error, it is possible to determine the limiting error from exploration results, regardless of the method by which the volume of the deposit or the quantity of minerals was calculated.

We find a brief description of the sources in the vicinity of Yakutsk in the works of G. N. Ognev and I. M. Svetozarov. However, due to the specifics of their work, they could not give characteristics of these sources in connection with the geological structure of the area. In this article I will complement the previous researchers with new materials about sources obtained in 1939 as a result of the work of the hydrogeological team of the Yakut expedition of the USSR Academy of Sciences. Work was carried out on the right and left banks of the Lena River from the village of Kachikatsy-Pokrovskoye to the N. Kangalas mines. It is easy to see that the first group of springs is an undeniable indicator of subpermafrost waters. These waters are connected in the given area with Cambrian limestones and the lower layers of Jurassic deposits. Subpermafrost waters are of undoubted practical interest both for the water supply of the city of Yakutsk (where Cambrian lies at a depth of 450 m) and for the population of the Yakut A.S.S.R. The second group of springs, which is connected with the upper water-bearing layers, has no practical purpose for water supply.

To correctly resolve the issue of the nature of the stressed state of the pillar and the deformations it experiences, it is necessary to have a correct understanding of the method of applying load to the pillar, since the latter determines the nature of the deformation – plastic or, conversely, elastic‑brittle. In addition, it should be borne in mind that the very entry into operation of new chambers, which determines the increase in the load on the pillar, does not occur immediately, but rather slowly and without jumps, but gradually. Having reached its maximum value – the full weight of the overlying rock strata – the load is not removed from the pillar, but continues to act for an indefinitely long time, which forces us to take into account the influence of time when considering the deformations of the pillar. Thus, it should be recognized that all conditions for loading interchamber pillars and the work of the load itself meet the conditions for the manifestation of plastic deformations.

In the present article is given the determination of the understanding of cycle process as well as the treatment of the connection of the cycle process with the stakhanovs-movement. Beside this, there are given the conditions, which necessary for the organisation of the cycle work, according to the graphs (intensity of preparation, equipment, staff etc.) There are also given the data concerning the capacity of workers in the Krivoy Rog, as well as in the region ot the Upper Lace mines in U. S. A.

Natural draft, as is known, is the result of the difference in the weight of the air in the intake and return airways. In accordance with this, the depression of natural draft depends on weight, i.e., on the temperature and air pressure in the outgoing and incoming air currents. Moreover, depending on the depression developed by the exhaust or forcing fan, the air density of the return or intake current can vary within significant limits, so that, along with the natural draft formed as a result of the heating of the air and changes in its composition, there is also a draft created by the fan – an “artificially created natural draft”. Currently, in addition to calculation methods, a number of methods are known for directly measuring the depression of the natural draft of an existing mine. These methods are associated with changing the ventilation regime of the mine. By blocking the entire air current with a stopping (or bulkhead), one can directly measure the natural draft depression with a micromanometer, connecting it to both sides of the stopping.

When studying world experience, a strict critical approach to assessing the changes that can be observed in mining abroad in recent years is necessary. Of course, at present there is still no reason to talk about any stabilization of work methods and equipment used abroad; only for now we can talk about some basic directions, about some basic technical trends. Some trends in the development of technology for transporting minerals can be considered progressive and deserve the most serious attention. These provisions include: 1. Application in appropriate conditions of brake conveyors. 2. Full conveyorization of excavation areas with loading points moved to the main haulage tracks. 3. Wider use of existing types of loading and bulk loading machines. In particular, such a simple and reliable bulk loading mechanism as the duck's nose has been completely undeservedly forgotten. Application for underground haulage of diesel locomotives.

The present work — Fundamentals of Planning in the Coal Industry of the USSR — represents a stage in the development of addressing issues of industrial and mining planning under the conditions of the coal industry. In this work, the following issues are examined: economic program, workforce, wages, materials, operating costs, capital works, and the financial aspect. All of these issues are reviewed with consideration of the Stakhanov movement. The work is suitable both for technical personnel and for people engaged in planning within the coal industry, as well as for students of higher technical schools, and aims to raise their economic level of knowledge.