Influence of sample bulk composition on the accuracy of semi-quantitative spectral analysis. The precision of the analysis is the sum of all random confounders; the correctness of the analysis is the systematic error. The effect of sample bulk composition on systematic error, i.e., correctness of analysis, is well known. The effect of sample bulk composition on the accuracy of spectral analysis, however, depends on the methodology, spectral setup, and other factors specific to a particular laboratory.

One of the main obstacles to the introduction of mechanized fasteners in weak host rocks is the lack of data on the relationship between the magnitude of rock pressure taken up by the fastener and the area of the fastener. The present article is devoted to the determination of soil resistance to indentation depending on the diameter and material of a round die (metal or wood).

The splitting of coal seams is an extremely characteristic phenomenon and is noted by numerous researchers for all coal basins and deposits. Already about 100 years ago, the phenomenon of splitting coal seams found a correct explanation in the works of C. Lyaille. For the initial position in explaining this phenomenon he took the following well-known principle: not the sea level rises, and the earth falls, and, conversely, not the sea level falls, and the earth rises. In other words, C. Leyel associated the splitting of coal seams with oscillatory movements of the Earth's crust of a differentiated kind. This point of view was later universally recognized. The splitting of coal seams is currently explained by the manifestation of differentiated movements of separate parts of the Earth's crust, distinguishing between plastic deflections and deflections as a result of clastic sinking and rising.

The Suputinskoye lignite deposit is located 35 km southeast of Voroshilov, near the village of Kondratenkovo. Administratively, it is part of the Voroshilovsky District of Primorsky Krai. The territory of the Suputinskoye field has the shape of an elongated oval stretching from southwest to northeast for a distance of more than 22 km, with a maximum width of 7 km. The depth of the depression exceeds 600 meters. The area of the deposit (about 100 km2) can be divided into three sections according to a number of features: southwestern, central and northeastern.

Sudden emissions of coal and gas not only complicate the development of coal seams, reducing the rate of coal production and delaying the excavation of individual seams, but also are a great danger to the lives of workers. Foreign and domestic researchers put forward a number of hypotheses that differently explain this complex phenomenon of nature.