Environmental Improvement Of Opencast Mining

Existing classifications of waste dumps in the quarries are given and their phenomenological nature is clarified. The need to identify the essence of the term "dump" is shown as well as the idea of "dump" as an artificial formation with everted and mixed rocks distanced from the quarry. Essential classification of man-made rock formations in quarries is developed. Characteristic of variations of man-made waste formations in quarries is developed. To reduce harmful effects of open-pit mining, dumps should be substituted with strat-lays - man-made structures relevant to natural stratification of litho-substances. Construction of strat-lays would improve ecological and technological culture of open cast mining

Personalization of convolutional neural networks within the stress detection task using heart rate variability data

Stress detection is an active area of research with important implications for personal, occupational, and social health. Most modern approaches use features computed from multiple sensor modalities, i.e., grouping different types of data from multiple sources for processing. These include electrocardiogram, electrodermal activity, electromyogram, skin temperature, respiration, accelerometer data, etc. Also, traditional machine learning algorithms (decision tree, discriminant analysis, support vector machine, etc.) or fully-connected neural networks are mostly used. Using these methods requires large amounts of data. Researchers are considering different approaches to personalization or generalization of models relative to subjects, namely subject-independent and subject-dependent (initially personal or adapted) models. The aim of the presented work is to develop a method for detecting stress based on heart rate variability data, taking into account the process of personalization of neural networks. The use of a convolutional neural network is proposed. The dependence of accuracy on the length of the input signal is studied. The dependence of accuracy on the data dimensionality reduction layer (one-dimensional convolutional layer, maximizing and averaging pooling) used in the network is also considered. The importance of personalizing models is demonstrated to significantly increase the accuracy of models of specific subjects. It is shown that the proposed method, based on 60 intervals between heartbeats, makes it possible to binary determine whether a person is under stress. Personalization allowed increasing the accuracy from 91.8 % to 98.9 ± 2.6 %. The F1-score value increased from 0.907 to 0.983 ± 0.038. The proposed personalized networks can be used in systems for monitoring the functional state of a person. They can also be used as part of a system that grants or restricts access to private resources based on whether a person is currently at rest

Electronic structure and magnetic properties of the spin-1/2 Heisenberg system CuSe2O5

A microscopic magnetic model for the spin-1/2 Heisenberg chain compound CuSe2O5 is developed based on the results of a joint experimental and theoretical study. Magnetic susceptibility and specific heat data give evidence for quasi-1D magnetism with leading antiferromagnetic (AFM) couplings and an AFM ordering temperature of 17 K. For microscopic insight, full-potential DFT calculations within the local density approximation (LDA) were performed. Using the resulting band structure, a consistent set of transfer integrals for an effective one-band tight-binding model was obtained. Electronic correlations were treated on a mean-field level starting from LDA (LSDA+U method) and on a model level (Hubbard model). In excellent agreement of experiment and theory, we find that only two couplings in CuSe2O5 are relevant: the nearest-neighbour intra-chain interaction of 165 K and a non-frustrated inter-chain coupling of 20 K. From a comparison with structurally related systems (Sr2Cu(PO4)2, Bi2CuO4), general implications for a magnetic ordering in presence of inter-chain frustration are made.Comment: 20 pages, 8 figures, 3 table

Increase of efficiency of diamond and abrasive textural processing of the natural stone

Описано процес фінішної фактурної алмазно-абразивної обробки поверхонь деталей з природного каменю. Досліджено закономірності витягування алмазно-поліефірного волокна з розплаву. Наведено результати експериментальних досліджень впливу розмірів алмазних зерен і діаметру волокна, а також їх співвідношення на якість оброблених поверхонь. Показано, що завдяки виготовленню робочого шару інструменту з алмазно-поліефірного волокна, а також його калібруванню за діаметром забезпечується можливість бездефектної фактурної обробки природного каменю. Визначено найбільш доцільні конструкції інструменту, виходячи з розподілу коефіцієнта заповнення його поверхні робочим шаром і вимог до обробленої поверхні за шорсткістю та відбиваючою здатністю.Purpose. Research of laws of influence of a design and the characteristic of the tool, the size of diamond grains and diameter of an diamond-polyester fibre of which its working layer, on quality of the processed surfaces is formed, and also working out of tools which raise efficiency of impressive diamond and abrasive textural processing of the natural stone. Design/methodology/approach. Research of evolution of the form of a working layer of the tool is based on results of calculation of its wear rate on circular zones, use of a method of computer modelling and материализации models by way Rapid Prototyping. Findings. Laws pulling from melt diamond-polyester are investigated. Results of experimental researches of influence of the sizes of diamond grains and diameter a fibre, and also their relations on quality of the processed surfaces are resulted. It is shown, that thanks to manufacturing of a working layer of the tool from an diamond-polyester fibre, and also to its calibration on diameter possibility of faultless impressive processing of a natural stone is provided. Originality/value. The most rational designs of the tool, proceeding from distribution of factor of filling of its surface by a working layer and requirements to the processed surface on a roughness and reflectivity are defined.Описан процесс финишной фактурной алмазно-абразивной обработки поверхностей деталей с природного камня. Исследованы закономерности вытягивания алмазно-полиэфирного волокна из расплава. Приведены результаты экспериментальных исследований влияния размеров алмазных зерен и диаметра волокно, а также их отношения на качество обработанных поверхностей. Показано, что благодаря изготовлению рабочего слоя инструмента из алмазно-полимерного волокна, а также его калибровке по диаметру обеспечивается возможность бездефектной фактурной обработки природного камня. Определены наиболее рациональные конструкции инструмента, исходя из распределения коэффициента заполнения его поверхности рабочим слоем и требований к обработанной поверхности по шероховатости и отражающей способности

Влияние полимерных добавок на процесс электроформования и структуру нановолокнистых материалов

The effect of addition of polymeric blends to spinning solution on fiber diameter and on structure of the electrospun nanofibrous materials is investigated.В работе рассмотрено влияние полимерных добавок в прядильные растворы, оказываемое на диаметр волокон и структуру нановолокнистых материалов, получаемых методом электроформования