The genus Narcissus has several endemic, rare and/or threatened species in the Iberian Peninsula and North Africa. In vitro propagation is a useful tool for threatened plants conservation used in ex situ strategies. Thus, the aim of this work was to study the propagation in vitro of bulb scale explants of five endemic, rare and/or endangered Narcissus species from the Iberian Peninsula, treated with different PGR combinations. Initiation was achieved in half-strength Murashige and Skoog (MS) basal salts and vitamins, 10 g/L sucrose, 500 mg/L casein hydrolysate, 2 mg/L adenine, 10 mg/L glutathione and 5.5 g/L plant agar. In the multiplication phase, the highest bulblet proliferation was obtained in MS medium supplemented with 30 g/L sucrose and the combination of 10 μM 6-Benzylaminopurine (BAP) + 5 μM α-Naphthaleneacetic acid (NAA) in N. alcaracensis, N. eugeniae and N. hedraeanthus; 20 μM BAP + 5 μM NAA in N. jonquilla and N. yepesii. The highest rooting was obtained with 5 μM NAA + 1 μM Indole-3-butyric acid (IBA) for all species (>75%) and more than 80% of the produced bulblets were successfully acclimatized.

The achene morphology and pericarp anatomy of 12 taxa representing three genera ( Anemone, Hepatica, and Pulsatilla) of the subtribe Anemoninae were investigated using microtome and light microscopy to evaluate the taxonomic implications of achene characters. The achenes of Anemone were elliptical or obovoid and beaked, whereas the achene of Hepatica and Pulsatilla were obovoid and elliptical, respectively. Noticeable variations in both quantitative and qualitative features of achenes were observed among the species of the three genera. One-way analysis of variance indicated that the quantitative achene variables among the species were highly significant (P<0.001). Pearson’s correlation coefficient also showed a significant correlation between different achene variables. The pericarp structure, particularly the number of cell layers and cell forms in the exocarp and endocarp, seems to be very useful for species delimitation in Anemone and Hepatica. The nature of the endotesta could provide substantial proof for sub-generic classification in Anemone. Unweighted paired group analysis showed the utility of achene features for taxonomic groupings of the species within the studied genera. Although the specimen samples represented a limited range of taxa, the achene features and pericarp anatomy provided a reasonable source for the taxonomic treatment of the studied genera within the subtribe.

In this study, female gametophytes of Silene muradica, which is a gynodioecious species, were examined histologically. Buds and blossoms of S. muradica were used as the research material. They were collected in the Sivas province (Turkey) in July 2019, and fixed with ethanol:acetic acid solution (3:1, v/v). Flower parts were dissected under a stereo microscope. They were dehydrated in rising alcohol series and then embedded in Historesin. The sections were taken by a rotary microtome and stained with 0.5% Toluidine blue O. The ovary of S. muradica has three carpels and a single chamber, the ovules are arranged on a central column. The mature ovule is of the campylotropous type, crassinucellate and bitegmig. The megaspore mother cell undergoes regular meiotic division and forms a linear megaspore tetrad after meiosis. The development of the embryo sac is monosporic. The chalazal megaspore is functional and the others degenerate. The mature embryo sac is eight-nucleated and of the Polygonum type. The synergid cells and the egg cell are completely surrounded by the cell wall. Antipodal cells are temporary cells, which degenerate immediately after fertilization. Before fertilization, polar nuclei are fused in the central cell and form the secondary nucleus. The endosperm development is of the nuclear type. Nucellar tissue is permanent and forms perisperm in mature seeds. The embryo development is of the Caryophyllad type. In this study, the development of the female gametophyte of S. muradica, which was determined to be a gynodioecious species, was reported for the first time.

Explosions of coal dust are a major safety concern within the coal mining industry. The explosion and

subsequent fires caused by coal dust can result in significant property damage, loss of life in underground

coal mines and damage to coal processing facilities. The United States Bureau of Mines conducted

research on coal dust explosions until 1996 when it was dissolved. In the following years, the American

Society for Testing and Materials (ASTM) developed a test standard, ASTM E1226, to provide a standard

test method characterizing the “explosibility” of particulate solids of combustible materials suspended

in air. The research presented herein investigates the explosive characteristic of Pulverized Pittsburgh

Coal dust using the ASTM E1226-12 test standard. The explosibility characteristics include: maximum

explosion pressure, (Pmax); maximum rate of pressure rise, (dP/dt)max; and explosibility index, (Kst). Nine

Pulverized Pittsburgh Coal dust concentrations, ranging from 30 to 1,500 g/m3, were tested in a 20-Liter

Siwek Sphere. The newly recorded dust explosibility characteristics are then compared to explosibility

characteristics published by the Bureau of Mines in their 20 liter vessel and procedure predating ASTM

E1126-12. The information presented in this paper will allow for structures and devices to be built to

protect people from the effects of coal dust explosions.

The evaluation of threats connected with the presence of methane in coal seams is based on our

knowledge of the total content of this gas in coal. The most important parameter determining the potential

of coal seams to accumulate methane is the sorption capacity of coal a. It is heavily influenced by the

degree of coalification of the coal substance, determined by the vitrinite reflectance R0 or the content of

volatile matter V daf. The relationship between the degree of coalification and the sorption capacity in the

area of the Upper Silesian Coal Basin (USCB) has not been thoroughly investigated, which is due to the

zonation of methane accumulation in this area and the considerable changeability of methane content in

various localities of the Basin. Understanding this relationship call for in-depth investigation, especially

since it depends on the analyzed reflectance range. The present work attempts to explain the reasons for

which the sorption capacity changes along with the degree of coalification in the area of Jastrzębie (the

Zofiówka Monocline). The relationship between parameters R0 and V daf was investigated. The authors

also analyzed changes of the maceral composition, real density and the micropore volume. Furthermore,

coalification-dependent changes in the sorption capacity of the investigated coal seams were identified.

The conducted analyses have indicated a significant role of petrographic factors in relation to the accumulation

properties of the seams located in the investigated area of USCB.

The coal exploitation in the Upper Silesia region (along the Vistula River) triggers the strata seismic

activity, characterized by very high energy, which can create mining damage of the surface objects, without

any noticeable damages in the underground mining structures. It is assumed that the appearance of the

high energy seismic events is the result of faults’ activation in the vicinity of the mining excavation. This

paper presents the analysis of a case study of one coal mine, where during exploitation of the longwall

panel no. 729, the high energy seismic events occurred in the faulty neighborhood. The authors had analyzed

the cause of the presented seismic events, described the methods of energy decreasing and applied

methods of prevention in the selected mining region. The analysis concluded that the cause of the high

energy seismic events, during the exploitation of the longwall panel no. 729 was the rapid displacements

on the fault surface. The fault’s movements arose in the overburden, about 250 m above the excavated

longwall panel, and they were strictly connected to the cracking of the thick sandstone layer.

Geodesic measurements of mining area deformations indicate that their description fails to be regular,

as opposed to what the predictions based on the relationships of the geometric-integral theory suggest.

The Knothe theory, most commonly applied in that case, considers such parameters as the exploitation

coefficient a and the angle of the main influences range tgβ, describing the geomechanical properties of the

medium, as well as the mining conditions. The study shows that the values of the parameters a = 0.8 and

tgβ = 2.0, most commonly adopted for the prediction of surface deformation, are not entirely adequate in

describing each and every mining situation in the analysed rock mass. Therefore, the paper aims to propose

methodology for determining the value of exploitation coefficient a, which allows to predict the values

of surface subsidence caused by underground coal mining with roof caving, depending on geological and

mining conditions. The characteristics of the analysed areas show that the following factors affect surface

subsidence: thickness of overburden, type of overburden strata, type of Carboniferous strata, rock mass

disturbance and depth of exploitation. These factors may allow to determine the exploitation coefficient a,

used in the Knothe theory for surface deformation prediction.

One of the main purpose of accurate blasting in open pit mining is to achieve optimum rock fragmentation.

The degree of rock fragmentation plays a significant role in order to control and minimise the

overall production cost including loading, hauling and crushing. In the present paper, the application of

a Number-Size (N-S) fractal model is intended to classify the blast fragmentation size in the Jalal-Abad

iron mine, SW Iran, using GoldSize image analysis software for four blasting with the obtained result

being compared with Kuz-Ram curves. To do this, the fractal dimensions via N-S log-log plots were

generated based on the output of the GoldSize software. The results indicated that the fragmented rocks

have a multifractal nature with four/five different fragmented populations in terms of size namely; the fine

rocks with the size of less than 16 cm, Mean-fragment values between 16 and 45 cm, In-range between

45 and 70 cm and finally, oversize larger than 70 cm.

Gas emissions from underground sites to the atmosphere depend on many factors. Pressure drops are considered to be the most important. However, emissions can also be observed during the initial phase of the pressure rise, following a previous drop in pressure. On the other hand, gas emissions may not be detected when the pressure drops, especially when a previous pressure rise has taken place. The aim of the research was to determine the role of variations in baric tendency on airflow rate and its direction. To solve this problem a numerical model was built utilizing the Ansys Fluent software package. Subsequently, three scenarios of baric tendency variations were tested: a) rise – drop, b) drop – drop, c) drop – rise. The results showed inert behavior of gases. Under scenario (c), 1 hour after the change in tendency gases still were flowing out to the atmosphere. Considering scenario (a), it was proved that even during a pressure drop gas emissions do not take place, which can be crucial for further determination of the gas hazard at the surface or for assessment of the rate of gas emissions from a particular gas emitter. Scenario (b) merely gave an overview of the process and was mainly used for validation purposes. It gave a maximal CO2 concentration of 2.18%vol (comparable to measurements) and a CO2 mass flow rate 0.15kg/s. Taking into account greenhouse gas emissions this amounted to 514 kg CO2/h.

In order to optimize the stope structure parameters in broken rock conditions, a novel method for the optimization of stope structure parameters is described. The method is based on the field investigation, laboratory tests and numerical simulation. The grey relational analysis (GRA) is applied to the optimization of the stope structure parameters in broken rock conditions with multiple performance characteristics. The influencing factors include stope height, pillar diameter, pillar spacing and pillar array pitch, the performance characteristics include maximum tensile strength, maximum compressive strength and ore recovery rate. The setting of influencing factors is accomplished using the four factors four levels Taguchi experiment design method, and 16 experiments are done by numerical simulation. Analysis of the grey relational grade indicates the first effect value of 0.219 is the pillar array pitch. In addition, the optimal stope structure parameters are as follows: the height of the stope is 3.5 m, the pillar diameter is 3.5 m, the pillar spacing is 3 m and the pillar array pitch is 5 m. In-situ measurement shows that all of the pillars can basically remain stable, ore recovery rate can be ensured to be more than 82%. This study indicates that the GRA method can efficiently applied to the optimization of stope structure parameters.

It is meaningful to study the issues of CO migration and its concentration distribution in a blind gallery to provide a basis for CO monitoring and calculation of fume-drainage time, which is of a great significance to prevent fume-poisoning accidents and improve efficiency of an excavation cycle. Based on a theoretical analysis of a differential change of CO mass concentration and the CO dispersion model in a fixed site, this paper presents several blasting fume monitoring test experiments, carried out with the test location to the head LP in arrange of 40-140 m. Studies have been done by arranging multiple sensors in the arch cross-section of the blind gallery, located at the Guilaizhuang Gold Mine, Shandong Province, China. The findings indicate that CO concentrations in the axial directions are quadratic functions with the Y and Z coordinate values of the cross-section of the blind gallery in an ascending stage of CO time- -concentration curve, with the maximum CO concentrations in Y = 150 cm and Z = 150 cm. Also, the gradients of CO concentration in the gallery are symmetrical with the Y = 150 cm and Z = 150 cm. In the descending stage of CO time-concentration curve, gradients of CO concentration decrease in lateral sides and increase in the middle, then gradually decrease at last. The rules of CO concentration distribution in the cross-section are that airflow triggers the turbulent change of the CO distribution volume concentration and make the CO volume concentration even gradually in the fixed position of the gallery. Moreover, the CO volume concentrations decrease gradually, as well as volume concentration gradients in the cross-section. The uniformity coefficients of CO concentration with duct airflow velocities of 12.5 m/s, 17.7 m/s and 23.2 m/s reach near 0.9 at 100-140 m from the heading to the monitoring spot. The theoretical model of a one-dimensional migration law of CO basically coincides with the negative exponential decay, which is verified via fitting. The average effective turbulent diffusion coefficient of CO in the blind gallery is approximate to 0.108 m2/s. There are strong linear relationships between CO initial concentration, CO peak concentrations and mass of explosive agent, which indicates that the CO initial concentration and the CO peak concentration can be predicted, based on the given range of the charging mass. The above findings can provide reliable references to the selection, installation of CO sensors and prediction of the fume-drainage time after blasting.

The hereby paper is devoted to the analysis of operational properties of vibratory conveyors, which principle of operations is based on the Frahm’s dynamic elimination effect (Den Hartog, 1971). These conveyors, according to the data given by their producers have several advantages, among others, higher vibrations amplitudes at the same drive and exceptionally low dynamic forces transmitted to the foundation. The simulation model of such conveyor loaded with a feed was created in this work and investigations of the transport efficiency and forces transmitted to the foundation at stationary states as well as at start up and coasting periods were performed. Analytical tests of vibrations during unsteady motion periods were also performed and the method of determining maximum amplitudes of conveyors in the transient resonance during coasting was proposed. The research results indicate the possibility of a wide application of this type of machines in loose materials handling in various industry branches.

The paper presents a new method for measuring the strain and load of wire ropes guide using fiber optic sensors with Bragg gratings. Its principle consists in simultaneous fiber optic measurement of longitudinal strain of the rope and transverse strain of the bolt fixing the rope. The tensometric force transducers which have been used so far were only able to determine the load in the head securing the rope through an indirect measurement using a special strain insert. They required calibration, compensation of temperature changes, as well as periodic checking and calibration. The head fastening the rope required significant design changes. Measurement based on fiber optic sensors does not have these drawbacks and is characterized by a much higher accuracy and safety of measurements, because the working medium is light. The fastening head does not change. The measurement of the rope load may be based on the change of strain value or indirectly by means of measuring the deflection of the bolt fixing the rope holder. The proposed solution consists in placing the optical fiber with Bragg grating inside the bolt. It enables continuous measurements with a frequency of 2 kHz. A special test bench was built at the Research and Supervisory Centre of Underground Mining. Testing on guide ropes was carried out in a mining hoist in the Piast mine.

The presented paper describes the results of an experiment determining the instantaneous values of velocity vector components of the air stream at selected spots of the boundary layer formed at the sidewalls of the mine heading in the ŁP type steel arch support. The experiment was carried out in a mine heading in an active hard coal mine. A 3-axis thermoanemometric probe was used to obtain three-dimensional distributions of the velocity and turbulent values, such as turbulence intensity and turbulent kinetic energy of the flowing ventilation air stream. The analysis of the measurement results was aided by a numerical solution of the discussed case of flow. The research results presented in this paper provide a basis for extensive studies of the description of velocity distribution and other turbulent quantities within the near-sidewall structures of a mine heading. The objective of these tasks is to improve the accuracy and reliability of numerical calculations relating to air flow in mine headings.

The evaluation accuracies of rock mass structures based on the ratings of the Rock Quality Designation (RQD) and discontinuity spacing (S) in the Rock Mass Rating (RMR) system are very limited due to the inherent restrictions of RQD and S. This study presents an improvement that replaces these two parameters with the modified blockiness index (Bz) in the RMR system. Before proceeding with this replacement, it is necessary for theoretical model building to make an assumption that the discontinuity network contains three sets of mutually orthogonal disc-shaped discontinuities with the same diameter and spacing of discontinuities. Then, a total of 35 types of theoretical DFN (Discrete Fracture Network) models possessing the different structures were built based on the International Society for Rock Mechanics (ISRM) discontinuity classification (ISRM, 1978). In addition, the RQD values of each model were measured by setting the scanlines in the models, and the Bz values were computed following the modified blockiness evaluation method. Correlations between the three indices (i.e., Bz, RQD and S) were explored, and the reliability of the substitution was subsequently verified. Finally, RMR systems based on the proposed method and the standard approach were applied to real cases, and comparisons between the two methods were performed. This study reveals that RQD is well correlated with S but is difficult to relate to the discontinuity diameter (D), and Bz has a good correlation with RQD/S. Additionally, the ratings of RQD and S are always far from the actual rock mass structure, and the Bz ratings are found to give better characterizations of rock mass structures. This substitution in the RMR system was found to be acceptable and practical.

The geodetic measurements optimization problem has played a crucial role in the mining areas affected by continuous ground movement. Such movements are most frequently measured with the classical geodetic methods such as levelling, tachymetry or GNSS (Global Navigation Satellite System). The measuring techniques are selected with respect to the dynamics of the studied phenomena, surface hazard degree, as well as the financial potential of the mining company. Land surface changes caused by underground exploitation are observed with some delay because of the mining and geological conditions of the deposit surroundings. This delay may be considerable in the case of salt deposits extraction due to slow convergence process, which implies ground subsidence maximum up to a few centimeters per year. Measuring of such displacements requires high precision instruments and methods. In the case of intensely developed urban areas, a high density benchmark network has to be provided. Therefore, the best solution supporting the monitoring of vertical ground displacements in the areas located above the salt deposits seems to be the Sentinel 1-A radar imaging satellite system. The main goal of the investigation was to verify if imaging radar from the Sentinel 1 mission could be applied to monitor of slow ground vertical movement above word heritage Wieliczka salt mine. The outcome of the analysis, which was based on DInSAR (Differential SAR Interferometry). technology, is the surface distribution of annual subsidence in the period of 2015-2016. The comparison of the results with levelling confirmed the high accuracy of satellite observations. What is significant, the studies allowed to identify areas with the greatest dynamics of vertical ground movements, also in the regions where classical surveying was not conducted. The investigation proved that with the use of Sentinel-1 images sub centimeters slow vertical movements could be obtained.

The main objective of this study was to assess the environmental impact of the subsurface geological structure in Nam Son landfill by hydrogeophysical method. The Electrical Resistivity Tomography (ERT), Self- -Potential (SP) and Very Low Frequency (VLF) method was used for geological structure investigation. Three profiles (total 900 m long) of two-dimensional ERT, VLF density sections and 180 SP data points scattered within the study area near the disposal site were implemented. Surface water and groundwater samples were collected from 10 sites in the area for hydrochemical analysis. Interpretations of geophysical data show a low resistivity zone (<15 Ω m), which appears to be a fully saturated zone with leachate from an open dumpsite. There is a good correlation between the geophysical investigations and the results of hydrochemical analysis.

Lower Carboniferous limestone has been extracted in the “Czatkowice” open-pit hill-slope quarry in southern Poland since 1947, for the needs of metallurgical and building industries, as well as farming. We can distinguish two aquifers in the Czatkowice area: the Quaternary porous aquifer and the Carboniferous fissure-porous one. Two vertical zones representing different hydrodynamic characteristics can be indentified in the Carboniferous formations. One is a weathering zone and the other one the zone of fissures and interbedding planes. Groundwater inflows into the quarry workings have been observed at the lowest mining level (+315 m above the sea level (asl)) for over 30 years. This study concerns two hypotheses of the sources of such inflows originating either from (a) the aeration zone or from (b) the saturation zone. Inflows into the quarry combine into one stream flowing gravitationally to the doline under the pile in the western part of the quarry. This situation does not cause a dewatering need. Extending eastward mining and lowering of the exploitation level lead to increased inflows.

Lower Carboniferous limestone has been extracted in the “Czatkowice” open-pit hill-slope quarry in southern Poland since 1947, for the needs of metallurgical and building industries, as well as farming. We can distinguish two aquifers in the Czatkowice area: the Quaternary porous aquifer and the Carboniferous fissure-porous one. Two vertical zones representing different hydrodynamic characteristics can be indentified in the Carboniferous formations. One is a weathering zone and the other one the zone of fissures and interbedding planes. Groundwater inflows into the quarry workings have been observed at the lowest mining level (+315 m above the sea level (asl)) for over 30 years. This study concerns two hypotheses of the sources of such inflows originating either from (a) the aeration zone or from (b) the saturation zone. Inflows into the quarry combine into one stream flowing gravitationally to the doline under the pile in the western part of the quarry. This situation does not cause a dewatering need. Extending eastward mining and lowering of the exploitation level lead to increased inflows.

In technology of coal fines beneficiation in Poland mainly fines jigging processes are in use. In case of steam coal fines beneficiation it is till 80% of the whole amount of produced assortments, while in case of coking coal fines it is 100%. The necessary condition of not homogenous feed separation which is directed to beneficiation process in pulsating water stream is a sufficient liberation of particles. The stratification of particles in working bed causes that particles of certain size, density and shape gather in individual layers in working bed of jig. The introduction of sufficient amount of additional water determines appropriate liberation of particles group, which generates partition into concentrate and tailings. The paper presents the results of sampling of industrial jig used for the beneficiation of coal fines by three various settings of additional amount of water under sieve which is directed to jigging. These amounts were equal to 35, 50 and 70 [m3/h]. Collected samples of separation products were then sieved into narrow particle size fractions and divided into density fractions. In such narrow size-density fractions the coordinates of partition curves were calculated for tailings of hard coal fines, which were subsequently approximated by means of Weibull distribution function. The separation precision measured by separation density, probable error and imperfection were determined on the basis of obtained model separation curves. The evaluation of separation effects was performed for a wide particle size fraction: feed directed to jigging process and narrow particle size fractions. The analysis of separation results in size-density fractions allowed to determine the influence of particle size change on the value of probable error. The results of separation precision in size-density fractions were compared with effects of separation of wide particle fraction, i.e. feed directed to jigging process.

To solve the problem of large deformation soft rock roadway with complicated stress condition in Baluba copper mine, the characteristics of roadway deformation and failure modes are analyzed deeply on the basis of geological survey. Combined with the theoretical analysis and numerical simulation, the new reinforcement technology with floor mudsill and grouting anchor cable is proposed. Moreover, the three dimension numerical simulation model is established by the software FLAC-3D, the support parameter is optimized by it. The results show that the optical array pitch of the U-steel shelf arch is 0.8 m, and the optical array pitch of the grouting anchor cable is 2.4 m. At last, the field experiments are done all over the soft rock roadway. Engineering practice shows that the deformation of soft rock roadway in Baluba copper mine is effectively controlled by adopting the new reinforcement technology, which can provide certain references for similar engineering.

The article concerns investigations over benefits of application of HRC devices into sulphide copper ore processing plant. High pressure comminution appears to be very effective technology in hard ore processing circuits, especially in terms of energy consumption. This can be particularly observed in downstream grinding and beneficiation operations. A series of pilot-scale crushing tests in HRC roller press for various levels of operating pressure, were performed. HRC crushing effectiveness along with downstream grinding process course for each crushing product were also under analysis. The investigations were supplemented by analysis of flotation process effectiveness and impact of the process of high-pressure comminution on environment (dust emission). The results of investigation show that operating pressure level influences the obtained comminution results (comminution degree, yield of finest particle size fractions). The grinding effectiveness, measured through production of the finest particle size fractions was significantly influenced by the operating pressure. The results show that higher values of operating pressure (4.0 and 4.5 N/mm2) are not as efficient within this scope as the pressure 3.5 N/mm2. Dust emission is also correlated with the operating pressure value.

The article presents the results of tests on SHC-40 hydraulic props equipped with two types of valve blocks: standard (with spring steel cylinder) and BZG-2FS (with gas spring). The research was conducted using impact mass of 4,000 kg and with extreme dynamic load of free fall impact mass of 20,000 kg released from different heights h. The dynamic tests involved a camera with the speed of image capture up to 1,200 frames/sec, which made it possible to register the stream of liquid at the dynamic load and to determine the valve opening time. The study conducted on SHC-40 NHR10 props equipped with two types of valve blocks: a standard and the BZG-2FS fast acting relief, showed that the prop with the BZG-2FS block is more suitable and more effective in the case of areas with high risk of mining tremors and rapid stress relief of a seam. Research methodology developed in the Central Mining Institute combines digital recording technique of pressure in a prop and fast registration of the images, and allows to acquire more accurate analysis of dynamic phenomena in the prop during testing.