The article presents research results of the strength parameters of HPC achieved in various research conditions. The research was carried out on substantially different samples, both as to the size as the slenderness ratio. Moreover, the assessment of the effect of speed of a load on strength parameters as well as other factors which in a significant way show the difference in the strength values was made. For comparison, the results were also applied to the relations known in ordinary concrete.

In this paper a mathematical model enabling the analysis of the heat-flow phenomena occurring in the waterwalls of the combustion chambers of the boilers for supercritical parameters is proposed. It is a one-dimensional model with distributed parameters based on the solution of equations describing the conservation laws of mass, momentum, and energy. The purpose of the numerical calculations is to determine the distributions of the fluid enthalpy and the temperature of the waterwall pipes. This temperature should not exceed the calculation temperature for particular category of steel. The derived differential equations are solved using two methods: with the use of the implicit difference scheme, in which the mesh with regular nodes was applied, and using the Runge-Kutta method. The temperature distribution of the waterwall pipes is determined using the CFD. All thermophysical properties of the fluid and waterwall pipes are computed in real-time. The time-spatial heat transfer coefficient distribution is also computed in the on-line mode. The heat calculations for the combustion chamber are carried out with the use of the zone method, thus the thermal load distribution of the waterwalls is known. The time needed for the computations is of great importance when taking into consideration calculations carried out in the on-line mode. A correctly solved one-dimensional model ensures the appropriately short computational time.

The paper is focused on properties testing of materials used in form of iso-exo sleeves for risers in ferrous alloys foundry. They are grainyfibrous

materials, containing components which initiate and upkeep exothermic reaction. Thermo-physical parameters characterizing such

sleeves are necessary also to fill in reliable databases for computer simulation of processes in the casting-mould layout. Studies with use of

a liquid alloy, especially regarding different sleeves bring valuable results, but are also relatively expensive and require longer test

preparation time. A simplified method of study in laboratory conditions was proposed, in a furnace heated to a temperature above ignition

temperature of sleeve material (initiation of exothermic reaction). This method allows to determine the basic parameters of each new

sleeve supplied to foundries and assures relatively quick evaluation of sleeve quality, by comparison with previous sleeve supplies or with

sleeves brought by new providers.

The aim of this study was to evaluate the influence of the newly isolated Lactobacillus plantarum LUHS135 and Lactobacillus paracasei LUHS244 strains grown in potato juice (with a cell count of 8.0-9.0 log10 CFU/ml) on the blood and faeces parameters of exercising horses. The horses were classified into four different groups: a control group (which received no probiotics); the first group (which received 200 ml of L. plantarum culture in potato juice); the second group (which received 200 ml of L. paracasei culture in potato juice); and the third group (which received an L. plantarum and L. paracasei mix (with the mix consisting of 100 ml of each). Indices for the blood and faeces microflora were obtained before and after treatment of horses (on days zero and thirty). It was observed that the count for lactic acid bacteria (LAB) in the faeces was significantly higher on day thirty, whereas it was lower when it came to the total enterobacteria count (TCE). Despite the ambiguous influence of any treatment on blood parameters, the L. plantarum × L. paracasei mixture increased the concentration of HGB and O2 saturation in blood samples which were taken from the horses. L. paracasei significantly decreased the lactate concentration levels in horse blood samples. As a result of the present study, it can clearly be seen that the strains being used revealed their potential application as probiotics; however, further studies are required to prove the survival and action mechanisms of the newly isolated strains.

The effect of monoterpenoid 1,8-cineol on the toxicity and physiology of elm leaf beetle, Xanthogaleruca luteola Müller under laboratory conditions (26 ± 1°C, 65 ± 10% RH and 16L : 8D h) was investigated. Initially, LC30 and LC50 values of the constituent were estimated to be 23.5 ppm and 31.9 ppm for the last instar larvae after 48 h, respectively. Significant changes were observed in the values of relative growth rate (RGR), efficiency of conversion of ingested food (ECI), efficiency of conversion of digested food (ECD), approximate digestibility (AD) and consumption index (CI) between control and treated larvae with 1,8-cineol. The amounts of protein, glucose and urea decreased in the treated larvae in comparison with control. Similar findings were observed in the activities of alkaline phosphatase and lactate dehydrogenase while the activities of glutathione S-transferase and esterase significantly increased in the treated larvae using CDNB and α-naphtyl acetates as the substrates. Morphological and histological changes brought about by 1,8-cineol in the present study are indicative of growth inhibition targeting specific organs such as those of reproduction. We believe that 1,8-cineol can be considered as a safe and environmentally friendly compound.

This paper presents an analysis of the stator teeth geometry impact on the parameters of the 8-pole radial magnetic bearing. In this paper, such parameters as current gain and position stiffness have been analysed. Additionally, we have proposed criteria for evaluating the characteristics of these parameters by calculating the variability of current gain and position stiffness. The research has been performed by solving the magnetic bearing actuator boundary problem using the finite element method. Magnetic force has been calculated using the Maxwell stress tensor method. Other parameters, such as current gain and position stiffness have been calculated as partial derivate of the force with respect to control current and position of the rotor.

This is an extended research of the paper (Islam et al., 2011) conducted to obtain a universal set of interaction parameters of the model NRTL over the temperature range 10 - 100 °C for hexane-butanol-water system; meaning for binary pairs hexane-butanol, butanol-water and hexane-water; and for ternary system hexane-butanol-water. Thorough investigations of data selections for all binary pairs (Vapor-Liquid Equilibrium (VLE), Liquid-Liquid Equilibrium (LLE)), infinite dilution activity coefficient (γ∞), infinite dilution distribution coefficient (Dsw), excess enthalpy (HE), and for ternary system (LLE of hexane-butanol-water) were carried out. Finally quadratic temperature dependent interaction parameters were estimated regressing all the mentioned data and in each case calculated results were compared with literature values. The comparisons showed an overall percentage of error within 15% for the mentioned phase equilibrium calculations.

The paper presents a proposal of using additional statistical parameters such as: standard deviation, variance, maximum and minimum increases of the observed value that were determined during measurements of temperature fields created on the surface of the tested electrochemical capacitor. The measurements were carried out using thermographic methods in order to support assessment of the condition of electrochemical capacitor under classic durability tests based on methods of determination of capacity and equivalent series resistance. The possibility of using some statistical parameters in assessment of the electrochemical capacitor quality was illustrated. The applied measurement methodology and the results of research associated with the classic methods of supercapacitors’ assessment are presented. The obtained results indicate that the variability of some statistical parameters of temperature fields can be directly related to changing the values of standard parameters describing electrochemical capacitor, which are capacitance and equivalent series resistance.

The paper presents application of a modified, symmetrical Bouc-Wen model to simulate the mechanical behaviour of high-frequency piezoelectric actuators (PAs). In order to identify parameters of the model, a two-step algorithm was developed. In its first stage, the mechanical parameters were identified by taking into account their bilinear variability and using a square input voltage waveform. In the second step, the hysteresis parameters were determined based on a periodic excitation. Additionally, in order to reduce the influence of measurement errors in determination of selected derivatives the continuum wavelet transform (CWT) and translation-rotation transformation (TRT) methods were applied. The results proved that the modified symmetrical Bouc-Wen model is able to describe the mechanical behaviour of PAs across a wide frequency range.

In the paper, the variation of the intensity of the geomagnetic field force is analysed in time and space. For the research, the data from measurements of the intensity of the geomagnetic field force at four airports (Kaunas, Klaip˙eda, Palanga andVilnius) and 6 geomagnetic field repeat stations aswell as the data from Belsk Magnetometric Observatory (Poland) were used. For the data analysis, the theory of covariance functions was applied. The estimates of the cross-covariance functions of the measured intensity of the geomagnetic field force or the estimates of auto-covariance functions of single data were calculated according to the random functions created from the force intensity measurement data arrays. The estimates of covariance functions were calculated upon varying the quantization interval on the time scale and applying the software created using Matlab package of procedures. The impact of radars of airports on the intensity of geomagnetic field variation and on changes of their covariance functions was established.

Today, a cascaded system of position loop, velocity loop and current loop is standard in industrial motion controllers. The exact knowledge of significant parameters in the loops is the basis for the tuning of the servo controllers. A new method to support the commissioning has been developed. It enables the user to identify the moment of inertia as well as the time constant of the closed current loop simultaneously. The method is based on the auto relay feedback experiment by Aström and Hägglund. The model parameters are automatically adjusted according to the time behaviour of the controlled system. For this purpose, the auto relay feedback experiment is combined with the technique of gradual pole compensation. In comparison to other existing methods, this approach has the advantage that a parametric model for the open velocity loop is derived directly.

The paper presents an adapted least squares identification method for reduced-order parametric models. On the example of the open velocity loop, different model approaches were implemented in a motion control system. Furthermore, it is demonstrated how the accuracy of the method can be improved. Finally, experimental results are shown.

The behaviour of concrete under quasi-static loadings for uniaxial compression, tension and planestress conditions is studied. The failure criteria of concrete are discussed as well as the methodsof constitutive parameters identification are elaborated. The attention is focus on an energeticinterpretation of selected failure criteria. The numerical example with concrete damage plasticitymaterial model is shown.

The present work consists of a statistical study of the monaural (lateral-reflection fractions and level) and binaural acoustic parameters (inter-aural cross-correlation coefficients) that evaluate the amount of early and late lateral acoustic energy encountered in 9 performance halls in Andalusia (southern Spain). Hall volumes range between 6,163 m3 and 34,594 m3 and all enclosures are used for presentations of symphonic concerts and other music performances. The majority of these venues are located in provincial capitals of the community and often constitute the only premises in the city where symphonic concerts can be held. The acoustic parameters under study here were derived from impulse responses analyses using a sine-sweep signals which were generated and processed by WinMLS 2004 software in the octave- band frequency centred from 125 to 4 kHz, and all parameters were spectrally averaged according to the ISO 3382-1 standard. A comparison is presented of monaural experimental results as a function of source- receiver distance with the prediction of Barron’s revised theory for concert halls, and the analyses of the acoustic parameter results are carried out in terms of their respective just noticeable differences: at the many microphone positions for the two source positions on stage, for the spatial distribution of seats in the audience zone relative to the central axis (for left- and right-hand sides) of the rooms, and for the presence of the orchestra shell on stage. Results reveal that the orchestra shell propitiates a perceptible decrement in the values of the early lateral energy fraction and an increment in the late lateral level at the audience seats. In addition, a regression study reveals that the two kinds of measures of laterality, monaural and binaural, are correlated when the hall-average data is considered, but they remain uncorrelated when all individual positions are used. Likewise, the ranges of variation of the acoustic parameters found in these halls are narrower than those specified in the ISO 3382-1. The paper concludes with a discussion on the relationships of hall-average data of the five parameters with eight geometric and acoustic variables.

Inductive loop sensors are widely used for detection of presence, measurement of parameters as well as classification of vehicles. Vehicle classification may be performed based on their magnetic profiles. The magnetic profile is a signal which is proportional to the resultant of an impedance change of the sensor, caused by the measured object (the changes are minor - of the order of 1%). Generator and bridge circuits are most commonly used as conditioning circuits for such sensors. As a result we can obtain one output signal proportional to total changes of sensor parameters (R and L). In this paper, a modified bridge circuit that allows independent measurement of the components (R and L) of the sensor's impedance, has been proposed. With that provided, it is possible to receive broader information on the object, which allows higher classification resolution. This paper provides the concept of a circuit, model testing results, processing algorithms used and the test results of a real circuit.

The underground mining of coal deposits in the Upper Silesian Coal Basin (GZW) re-sults in an imbalance in the distribution of the stress in the rock mass, both in the immediate and distant surroundings of mining excavations. The occurrence of seismic tremors, among others, is the consequence of this process,. The intensities of seismic phenomena, which occur in several regions of the GZW (Bytomian Basin, Main Saddle, Main Basin, Kazimierzowska Basin, and the Jejkowice Basin) are very diverse, ranging from tremors unrecognizable by humans to strong tremors of the nature of weak earthquakes (Patyńska and Stec 2017). During the period of 15 years, i.e. from 2001 to 2015, the level of seismic activity changed and de-pended on both the intensity of the excavation work and the variability of the lithological and tectonic structures. On the other hand, the seismic activity analysis has shown that in recent years, despite a decrease in total output, seismic activity and rockburst hazard have increased. One of the rea-sons was the increase in mining output. Almost half of the output came from coal seams under the rockburst hazard. This resulted in an increase in the number of great energy tremors with the energy of 107, 108 and 109 J. It has been shown that the amount of energy tremors has a high impact on the level of the rockburst hazard. Between 2001 and 2015, as many as 20 rockburst were caused by seismic tremors above 107 J with 42 total phenomena (Patyńska 2002–2016). The purpose of characterizing the causes of this phenomenon was determined by the parameters characterizing the structure of the rock mass in places where the rockburst was recorded.

Anisotropy of variations of Polish mineral deposit parameters is rarely the subject of interest of geologists who carry on the assessment projects . However, if the anisotropy is strong its description and mathematical modeling are rational and justified as it may affect the accuracy of many calculations suitably for mining geology and mining engineering, e.g. estimation of resources and grade of particular raw-material, interpolation of deposit parameters values and construction of their contour maps, designing of optimum grade mining operations or densification of sampling grid. In geostatistics anisotropy is described with directional semivariograms which represent average variability of values of particular deposit parameter in various directions, depending on the distance between sampling sites. Convenient graphic presentation of anisotropy is map of directional semivariograms and good mathematical presentation are functions describing the anisotropy models.

The paper presents the results of geostatistical descriptions of various anisotropy types in selected examples of Polish mineral deposits. Taking into account the spherical variability model, the influence of anisotropy on the results of deposit parameters estimations has been theorized for both the interpolation point and calculation block (area). It was found that anisotropy is effective for parameters estimation if three mutually interrelated factors are considered: power of directional diversification of parameters variation, contribution of random component to total, observed variation of parameters and the range of semivariograms (autocorrelation) of parameter referred to the average sampling grid density.

The results demonstrate that anisotropy influences much more the estimations of parameters value in interpolation points than those of average values of parameters calculated for particular parts of deposit (calculation blocks). Moreover, anisotropy is unimportant when the random component of variability dominates the overall variability of analyzed parameter. Therefore, the simpler, isotropic variability model can be applied to geostatistical estimations of deposit parameters.

The paper presents the results of hydrogeological parameters determination carried out in the area of the Muschelkalk outcrop (Middle Triassic) near Tarnów Opolski. The studies consisted of a short pumping test in 16 piezometers and then their flooding and observation of water table recovery after the stopping of the pumping. The test allowed the values of hydraulic conductivity and specific capacity of Muschelkalk layers ranging from 8.56 · 10–8 m/s to 3.63 · 10–3 m/s and from 0.0075 to 128 m3/h/1mS, respectively, to be calculated. The wide range of values is related to the fact of studying the layers characterized by high permeability and water-bearing capacity (Karchowice Beds, Diplopora Beds and Górażdże Beds) as well as layers with low permeability (Gogolin Beds). The dense network of the research points made it possible to demonstrate the surface variability of rocks permeability and water- bearing capacity, determined mostly by the direction of outcrops of individual layers. The results of the conducted studies show that the most water-bearing zone of the area is related to the carbonate rocks of the Karchowice, Diplopora and Górażdże Beds, characterized by the highest values of hydraulic conductivity k (above 2 · 10–4 m/s) and specific capacity q (above 15 m3/h/1mS), in the belt stretching latitudinally through Kosorowice–Otmice. The studied area can be considered a Polish limestone-concrete field where several mines exploiting Muschelkalk carbonate rocks operate. The results of the conducted studies may be useful for the correct prognosis of the groundwater inflow either to already existing quarries or newly designed mines within the Major Groundwater Basins.