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The quality of bucket wheel excavators (BWEs) operations is largely influenced by the physical-mechanical (structure, mineralogical composition, plasticity, anisotropy, degree of fracturing etc.) and technological properties (compressive strength, tensile strength, shear strength, compaction, consolidation, cutting resistance etc.) of the rocks. If the excavated materials are relatively homogenous, without intercalations with excessive cutting resistance, it is not difficult to conduct the technological process. I...

The solving of the project of the Ministry of Agriculture of the Czech Republic dedicated to sustainable agricultural management in the North Western Bohemia is under way from 2015 to 2018. The Brown Coal Research Institute is the main participant of the project. This article briefly summarises new results of the research of the Most Basin localities restoration problems. The main attention is devoted to the research of experimental areas founded in different dump localities with different dump rocks and different...

The paper deals with the study of Powered roof support analysis, taking into account the interaction with surrounding rocks. In this respect, an analytical model of kinematics and load of the shield, a differential model of the shield-rock system equivalent stiffness and a Fuzzy logic based analysis of the parameters variation are presented. In the first two models, the classical approach of shield mechanics, the loading scheme was modified by taking into account the horizontal force acting between the roof and th...

The scientific paper proposed deals with the reliability analysis of the average usage time of the brake pads as components of the braking system of the industrial front-end loader and transporter machinery used in mining operations in Romania. The research was conducted at the request of several mining companies in Romania, that are using the front-end loader and transporter machinery in their daily operations. The study is based on the empirical information and the preliminary reliability results that were recor...

The article shows features of a soil, illustrated with cracks. These cracks are natural detail of a soil, which more humified and less dense, than the rest part of the soil. Author highlights frequency and depth of these cracks in a soil profile, which essentially affects on the functions of the soil at the disclosure. On the mastered for an agriculture soil, cracks come from surface, in spite of that top horizons of the soil were homogenized in processing. Cracks go through the most humified part of the soil, whi...

The paper deals with the theoretical and practical analysis of the influence that the cutting direction of the bucket wheel excavator has on the digging forces acting on the wheel. Usually, when the terrace cut technology is applied, the bucket wheel of the excavator cuts vertical chips where mainly the perpendicular to stratification digging method is predominant. All the laboratory trials - done on the test rig - were conducted mainly for this type of vertical chip cutting. In cases when the drop cut method is a...

Biochar is carbonized organic matter, which is prepared by pyrolysis and it content high amount of carbon. This material is currently very often mentioned in carbon sequestration and as an additive improving physicochemical and biological soil functions, especially soil aggregation, conductivity or pH. Thus biochar could be usefully toll for decreased erosion risk. The influence of biochar on soil microorganisms is still big question. Results of scientific work differ much. Problematic component of biochar is arom...

In most industrialized countries the problem of air pollution has become a major concern with significant social and political implications, is considered a barrier to economic and social development, drawing attention to these natural resources, materials and energy are not inexhaustible. In the literature are numerous researches on environmental pollution, correlated or not with the consequences on animals and food of animal origin, and not least on health human. In recent times the environmental pollution has d...

The scientific paper deals with the multi-criterion optimization of the teeth that are used on the buckets of bucket wheel excavators. From past theory and practice, it is known that geometry of the tooth greatly influences the cutting parameters and the endurance and the strength of the tooth itself. The dependencies between the cutting forces, the penetrating forces, the specific energy on the rake angle and the relation between this last one and the robustness of the tooth are somewhat contradictory, so in the ...

Pesticides alter the biological properties of the soil, leading to a complete loss of their fertility. Chestnut soils (meadow brown, light brown) are resistant to contamination by pesticides and by fertilizers in particular. We have carried out studies on the effect of the examined soil pollution with high doses of fertilizers and pesticides on the soil mesofauna representatives. The work is based on studying influence of anthropogenic impacts on soil biological activity in comparison with its main indicators, whi...

The performances of the excavation machines depend largely on the tool and overall machine characteristics and on the other hand on physical mechanical characteristics of the excavated rock. There were more theories based on analytical deductions to explain the main cutting parameters on the basis of basic physical mechanical properties of the excavated rock. In this paper we use a new methodology, based on reliable laboratory data, which make possible to obtain correlation and regression formulas in order to pred...