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We present a systematic investigation of the possible locations for the special point (SP), a unique feature of hybrid neutron stars in the massradius diagram. The study is performed within the two-phase approach where the high-density (quark matter) phase is described by the covariant nonlocal Nambu–Jona-Lasinio (nlNJL) model equation of state (EOS) which is shown to be equivalent to a constant-sound-speed (CSS) EOS. For the nuclear matter phase around saturation density different relativistic density functional EOSs are used: DD2p00, its excluded-volume modification DD2p40 and the hypernuclear EOS DD2Y-T. In the present contribution we apply the Maxwell construction scheme for the deconfinement transition and demonstrate that a simultaneous variation of the vector and diquark coupling constants results in the occurrence of SP "trains" which are invariant against changing the nuclear matter EOS. We propose that the SP train corresponding to a variation of the diquark coupling at constant vector coupling is special since it serves as a lower bound for the line of maximum masses and accessible radii of massive hybrid stars.

We used an isobar model to study the K+Σ− photoproduction reaction on a neutron target with focus on the resonance region. In order to achieve a reasonable agreement with the data, we included spin-3/2 and spin-5/2 nucleon resonances in a consistent formalism together with a Δ resonance and two kaon resonances on top of the Born terms. The free parameters of the model were adjusted to the data from the CLAS and LEPS Collaborations on differential cross sections and photon beam asymmetry. The cornerstone of this analysis was an upgrade of the fitting method. Previously, we used only the plain χ2 minimization, which could not prevent us from overfitting the data. We, therefore, introduced a regularization method, the least absolute selection shrinkage operator (LASSO), which, together with information criteria, restricts the number of nonzero parameters and prevents us from overfitting the data. In our analysis, we arrived at two models, fit M, whose parameters were fitted with the MINUIT code only, and fit L, where we used the more advanced LASSO. Both models describe the data in a similar way and we observe only slight differences in the dσ/dΩ data description at very forward angles where the fit M is flat whereas the fit L produces two broad peaks, and in the photon beam asymmetries above 2 GeV at backward kaon angles where the fit M produces a bump. Surprisingly, no hyperon resonances are needed for the correct data description in these models. On the other hand, the N(1720)3/2+ nucleon resonance was found to be very important in both models.

It was recently demonstrated [1] that the meson-baryon rescattering in the final state has a major impact on the magnitude and structure of the πΣ mass distributions observed in the γp → K+πΣ photoproduction. We discuss briefly several aspects of this work emphasizing the model dependence of the meson-baryon amplitudes, used to represent the final-state interaction, and the role of the adopted photoproduction mechanism.

We study kaon photoproduction off a neutron target using an isobar model. Recently acquired polarization data from the CLAS collaboration are incorporated in our analysis, while a novel fitting procedure is employed that allows us to reduce the number of parameters used with a minimal cost on the information content.

In March 2019 the HADES experiment recorded 14 billion Ag+Ag collisions at √sNN = 2.55 GeV as a part of the FAIR phase-0 physics program. In this contribution, we present and investigate our capabilities to reconstruct and analyze weakly decaying strange hadrons and hypernuclei emerging from these collisions. The focus is put on measuring the mean lifetimes of these particles.

In this paper existing active and passive radial guiding systems of railway vehicle wheelsets are presented. The new system described in this paper is based on non-direct measuring lateral forces in bogie elements. As a part of project development there where numerical calculations and experiments on a test stand carried out. As a main issue, there where investigated stress signals from extensometers mounted on guiding elements of wheelsets. In conclusions, there is made a comparison between values obtained from numerical and experimental tests.

The special point is a feature unique to models of hybrid neutron stars. It represents a location on their mass–radius sequences that is insensitive to the phase transition density. We consider hybrid neutron stars with a core of deconfined quark matter that obeys a constant–sound–speed (CSS) equation of state model and provide a fit formula for the coordinates of the special point as functions of the squared sound speed ( cs2 cs2) and pressure scale (A) parameters. Using the special point mass as a proxy for the maximum mass of the hybrid stars we derive limits for the CSS model parameters based on the recent NICER constraint on mass and radius of pulsar PSR J0740+6620, 0.36 < Cs min2 cs min2 < 0.43 and 80 < A[MeV/fm3] < 160. The upper limit for the maximum mass of hybrid stars depends on the upper limit for cs2 cs2 so that choosing cs,max2 cs,max2 = 0.6 results in Mmax < 2.7 M⊙, within the mass range of GW190814.

Contemporary gear pumps, although their design has been under development for over four centuries, keep being modernized and improved. The work presents an analysis of design solutions, taking into account their operational features. The analysis included units with internal mesh. Emphasis was put on the problem of ensuring high values of volumetric efficiency by minimizing leakage in the widest possible range of loads while maintaining the highest possible hydraulic and mechanical efficiency of the displacement unit. Increasing the volumetric efficiency of positive displacement pumps is an important factor in the pursuit of increase in working pressures in hydrostatic systems. An important factor in production of pumps is cost of their production, which often leads to possibility of introducing additional modifications in the pump structure. Often changes made to the materials used in construction of pumps, allow reduction in their mass or sensitivity to the action of the transported liquid. The paper indicates the developed and proprietary solutions in this area and presents the results of experimental research.

Problems with overheating and unstable temperature of industrial equipment are the reasons for generating significant costs that for companies. Solving the problems related to heat removal is a challenge in modern industry. Phase change materials are the solution to these challenges (PCM). These substances can accumulate and release large amounts of thermal energy during the phase change transition. The value of the phase transition enthalpy determines the energy storage capacity. The paper presents the results of phase transitions of selected materials. The measurements were carried out on a stand for testing phase change materials. The laboratory stand made it possible to determine the thermodynamic parameters of the phase transition. The substances analysed are kinds of paraffin of different chemical composition. Due to the diversity of substances, it is possible to analyse the influence of the chemical composition on possible uses in industrial applications for energy storage.

In this paper the new non-equilibrium model of heat and moisture transfer in heterogenous building materials is presented and tested. The new hygro-thermal model differs from the other approaches which are based on the classical assumption of instantaneous local mechanical, thermal and hygric equilibrium between vapour and water in the pores in building materials. Instead of this assumption the model uses the finite rate of transition of moisture from the liquid to the vapour state and vice versa while still keeping mechanical and thermal equilibrium between components of the medium. The linear kinetics of this transition is applied. The assessment of the model correctness is also performed in the paper. In the first step of the testing the model predictions were successfully verified with the reference data obtained numerically. Then the model was validated using reference data obtained experimentally. Finally, the influence of volumetric mass transfer coefficient between vapour and water as well as water and vapour in pores is investigated, i.e., kinetics of the vapour-water/water-vapour transition is analysed. During the model testing traditional building material were considered (i.e., ceramic brick). However, the model may be used for investigation of hygro-thermal behaviour of bio-based materials.

Pion beams are important tools to study features of baryonic resonances and their decay channels because resonances are produced in s-channel at fixed mass equal to √s. In 2014 the HADES collaboration has performed systematic measurements in the second resonance region scanning around the mass of the N*(1520). Pion beams at four momenta (0.654, 0.686, 0.738 and 0.787 GeV/c) impinging on polyethylene and carbon targets have been used. With the use of the multichannel Partial Wave Analysis (PWA) the role of the N*(1520) resonance in conjunction with the intermediate ρ-meson production has been studied. Preliminary results at 0.654 GeV/c on exclusive production of two pions (ηπ+π- and pπ-π0) in the final state are presented.

Radiative transition of an excited baryon to a nucleon with emission of a virtual massive photon converting to dielectron pair (Dalitz decays) provides important information about baryon-photon coupling at low q2 in timelike region. A prominent enhancement in the respective electromagnetic transition Form Factors (etFF) at q2 near vector mesons ρ/ω poles has been predicted by various calculations reflecting strong baryon-vector meson couplings. The understanding of these couplings is also of primary importance for the interpretation of the emissivity of QCD matter studied in heavy ion collisions via dilepton emission. Dedicated measurements of baryon Dalitz decays in proton-proton and pion-proton scattering with HADES detector at GSI/FAIR are presented and discussed. The relevance of these studies for the interpretation of results obtained from heavy ion reactions is elucidated on the example of the HADES results.

Omega phase particles can be observed by conventional SEM. Metastable Ti15Mo alloy was annealed at 500 °C for 16 hours. During annealing, ω phase particles grew and got chemically stabilized by expelling Mo atoms. As the result, these ellipsoidal particles, approx. 100 nm long and 50 nm wide can be observed using back-scattered electrons signal in conventional SEM due to chemical contrast. TEM study proved that these particles indeed belong to ω phase. Co-existence of β, ω and α phases was observed. Thin α lamellae were observed along with distorted ω phase particles by TEM.

Les courants marins à proximité d’une côte contrôlent le transport de sédiment et son évolution. Or leur estimation par des instruments sur site est difficile et coûteuse. Les systèmes de télédétection reposant sur des observations constituent une alternative prometteuse lorsque la mousse dérivante laissée après le passage de vagues déferlantes est visible. Pourtant, seules quelques méthodes ont été proposées à ce jour dans la littérature. Dans cet article, nous décrivons deux nouvelles méthodes : l’une basée sur les images vidéos considérées dans leur globalité et l’autre basée sur des timestacks le long de la côte. La première approche est une extension de la méthode Particle Image Velocimetry (PIV). La seconde approche produit une estimation de la composante parallèle à la côte des courants de surface en utilisant la transformée de Radon sur des séries temporelles de données en une dimension. Cette dernière nécessite moins de données. Les vidéos utilisées dans cet article proviennent d’une campagne menée sur la zone de l’embouchure de Mataquito dans la région de Maule au Chili. Elles font partie d’une étude sur l’évolution côtière de la zone de Mataquito après le tsunami chilien de 2010. Une comparaison a été également réalisée avec les mesures d’un courantomètre prises lors de la campagne du Truc Vert de 2008 en Aquitaine, France. Elle a eu lieu lors d’une tempête qui a provoqué l’évolution d’une barre sableuse.

In this paper, the authors are proposing a computer system built in the cloud-computing fashion for the collection of data from smartphones to achieve a crowdsensing-based quality assessment of roads, as well as detection, identification, and assessment of road artefacts (potholes, speed bumps, etc). The proposed information processing methods were based on Lambda architecture and the integration of different types of crowdsourced data to finally calculate the singular value of the human-readable road quality. Finally, the prototype implementation of the system for gathering, processing, integration, and processing the road quality data is also presented.

In this paper heat transfer during impingement of an array of 8×8 microjets on a hot surface was investigated. The influence of a ratio of a distance between a nozzle and hot plate (H/d) and microjet diameter-based Reynolds number (Red) on the temperature and heat transfer coefficient (HTC) on the hot plate were numerically studied. The numerical model which was based on the steady-state compressible Navier-Stokes equations and SST k-ω turbulence model was developed and applied for the analysis. During simulations the ratio of the distance between the nozzle and hot plate to the microjet diameter was H/d = 3.125, 25 and 50, while the microjet diameter-based Reynolds number was equal to Red = 690, 1100 and 1510. The ratio of the microjet pitch to the microjet diameter was s/d = 31.25. It was found that both the H/d ratio and Red significantly influenced flow patterns in the gap between the nozzle and hot plate as well as the temperature and HTC on the surface of the hot plate. With increase of the H/d ratio a more uniform distributions of the plate temperature and HTC were observed, while the rise in the Red intensified heat transfer on the hot plate.

This paper presents a concept of the air quality monitoring system design and describes a selection of data quality analysis methods. A high level of industrialisation affects the risk of natural disasters related to environmental pollution such as e.g. air pollution by gases and clouds of dust (carbon monoxide, sulphur oxides, nitrogen oxides). That is why researches related to the monitoring this type of phenomena are extremely important. Low-cost air quality sensors are more commonly used to monitor air parameters in urban areas. These types of sensors are used to obtain an image of the spatiotemporal variability in the concentration of air pollutants. Aside from their low price , which is important from a point of view of the economic accessibility of society, low-cost sensors are prone to produce erroneous results compared to professional air quality monitors. The described study focuses on the analysis of outliers as particularly interesting for further analysis, as well as modelling with machine learning methods for air quality assessment in the city of Lublin.

In the article, the simulation model of a one-phase full bridge diode rectifier with a current modulator in the input circuit is described. The proposed solution is characterized by the consumption of a sinusoidal current from a power grid, compatible in phase with the fundamental harmonic of voltage. The power circuit, as well as controlling parts of the constructed simulation model were presented. Moreover, selected results of the simulation model investigation are shown.

In the paper the equilibrium and non-equilibrium models of moisture transport across the wet building material are proposed and compared. The equilibrium condition between gaseous and liquid moisture phases in the first model is relaxed in the second one, where evaporation and condensation are driven by the difference between the actual moisture partial pressure and its saturation value. In both models moisture is assumed in the gaseous phase as well as continuous (funicular) and discontinuous (pendular) liquid phase. Moreover, the transport of moisture is tightly coupled with heat transfer, which is treated as the fully equilibrium process in both models. The proposed models are verified with numericalresults available in literature, namely with temporal variation of temperature in selected location in the building material. Additionally, predicted with both models temporal changes of the moisture content in three selected points and the total moisture content are compared. Both models produced similar results.

The HADES collaboration uses the e+e− production as a probe of the resonance matter produced in collisions at incident energies of 1-3.5 GeV/nucleon at GSI. Elementary reactions provide useful references for these studies and give information on resonance Dalitz decays (R→Ne+e−). Such processes are sensitive to the structure of time-like electromagnetic baryon transitions in a kinematic range where (off-shell) vector mesons play a crucial role. Results obtained in proton-proton reactions and in a commissioning pion-beam experiment are reported and prospects for future pion beam experiments and for first hyperon Dalitz decay measurements are described. The connection with the investigations of medium effects to be continued with HADES in the next years at SIS18 and SIS100 is also discussed.

Pion beams are perfect tools to probe resonance excitations at a fixed energy, thus properties of baryonic resonances and their coupling channels can be studied. The HADES Collaboration performed a systematic scan around the second resonance region at four different pion beam momenta 0.656, 0.69, 0.748 and 0.8 GeV/c in π− p reaction. The role of the N(1520) resonance in conjunction with the intermediate ρ-meson production has been studied in the framework of a partial wave analysis. Preliminary results on exclusive channels with one pion (π− p) and two pions (nπ+π− and pπ−π0) in the final state are presented.

The evolution of the deformation across the Y isotopic chain, in the vicinity of N = 60 boundary, has been studied using gamma spectroscopy methods. The nuclei of interest have been produced by neutron induced fission of 235U and 241Pu targets, during two experimental campaigns named EXILL and FIPPS at the Institute Laue-Langevin in Grenoble. The emitted gamma rays have been collected by HPGe and LaBr3 detectors providing the identification of the high-spin levels in the 94Y and 96Y isotopes up to 6 MeV excitation energy, as well as information about the half-lives of the in-band states in the 98Y nucleus. The obtained results shed new light on the onset of deformation in the neutron-rich Y isotopes and, in general, in the A ≈ 100 region.

The study of the emitted particles, comparing pre-equilibrium and thermal components, is a useful tool to examine the nuclear structure of emitters. Possible clustering effects, which may change the expected decay chain probability, could be highlighted on the competition between different reaction mechanisms. The NUCL-EX collaboration (INFN, Italy) has carried out an extensive research campaign on pre-equilibrium emission of light charged particles from hot nuclei. In this framework, the reactions 16O+30Si, 18O+28Si, 19F+27Al at 7 AMeV and 16O+30Si at 8 AMeV have been carried out using the GARFIELD+RCo array at Legnaro National Laboratories. Some anomalies in the α-particle emission channels have been evidenced in the measurement reported above, showing in an exclusive way the observed effects related to the entrance channels. The experimental results are compared to model prediction, for which the same filtering and complete event selection have been applied.

Water intake in rural settlements adjoining large cities is variable and depends on many factors. In these places increasingly often a change in the character of water use from rural to the one typical of urban housing estates is observed. This is due to the expansion of housing, especially single-family housing, and migration of people from large cities. As a consequence, the standard of home furnishings improves and water is used not only for domestic purposes, but also for watering gardens and greenery, the filling and operation of swimming pools, etc. Considering the above, the authors present the results of own research relating to the analysis of water intake in villages adjacent to Wrocław.

The field efficacy of a single dose treatment against natural M. capillaris infection using different anthelmintic drugs, extensively employed in ovine parasite control programs in Galicia (N.W. Spain), and the effect of protostrongylid infection on ovine respiratory functions, were evaluated. Five groups (n = 5) of ewes were used in this study; animals were treated with injectable ivermectin (0.2 mg/kg), levamisole (7.5 mg/kg) and albendazole (5 mg/kg) and monitored at 0, 7, 21, 42 and 63 days posttreatment (d.p.t.) by enumeration of the lungworm larvae per gram of faeces (l.p.g.) and determination of gas tension and pH in venous blood using an i-Stat portable clinical analyzer. No statistical difference was found either in larval elimination between untreated and treated groups or in the reduction in larval counts in all of the treated groups. A significant increase in partial oxygen tension (pO2) and saturation (sO2) between day 0 and 7 p.t. was observed in all treated animals. These values decreased significantly at day 21 to previous levels. There were no statistical differences in blood gases between uninfected and treated groups. We can conclude that under Galician field conditions, parasitic control programs are not totally effective against M. capillaris infection.

The drone is an unmanned aerial vehicle. Currently, many commercially available remote controlled flying toys are used to be called drones. This is an erroneous nomenclature, because the drone must have an autonomus flight function implemented. Due to it's simple mechanical construction, the most popular drones are in the form of a multirotor, in which arrangement the engines are placed in one plane. One of the most important advantages of this type of robots is the ability to maintain a certain position in space. Today, this allowed for e.g. taking photos from the air or inspecting hard-to-reach places. For use for environmental protection purposes, drone equipped with appropriate sensors and instrumentation may be used to monitor air pollution. The mechanical part of a quadrocopter flying robot was based on a TAROT frame with a 450mm engines spacing. The frame has been expanded with a dedicated set of legs to raise the clearance up to 150mm. Four dedicated EMAX MT2213 electric motors were installed on the frame, which are the main drive. They are characterized by the propeller hub-free-mounting, which minimizes possible imbalances. A single engine cooperating with a dedicated 10-inch propeller and a 4.5-inch pitch generates a maximum thrust of a 0.85kg. In the case of this system, it sums to a total of 3.4 kg. The weight of the ready to flight robot is 1.35 kg. To power the robot, a lithium-polymer battery with a capacity of 2.2 Ah is used, providing flight time of about 8 minutes. The basic work mode of the robot is a manual one, which means a self leveling mode with manual control. In addition to this mode, an autonomous navigation mode using GPS coordinates has been implemented. This navigation mode was also been tested during field tests. The operation of this navigation mode is very similar to the position maintaining mode, but operates on a larger scale. The robot in this mode is vectorically controlled, performing forwards/backwards and sideways movements to the set location.

One of the source of air pollutants is emission from local coal-fired boiler-houses and domestic heating boilers. The consequence of incineration of municipal waste is the introduction of additional pollutants into the atmosphere, including fly ash. The aim of this work was to evaluate the particle size distribution of fly ash emitted by coal combustion and co-incineration of coal with municipal waste in a domestic 18 kW central heating boiler equipped with an automatic fuel feeder. Mixtures of bituminous coal with different types of solid waste (5, 10 and 15% of mass fraction) were used. Solid waste types consisted of: printed, colored PE caps, fragmented cable trunking, fragmented car gaskets and shredded tires from trucks. During the incineration of a given mixture of municipal waste with bituminous coal, the velocity of exhaust gas was specified, the concentration and mass flow of fly ash were determined together with the physico-chemical parameters of the exhaust gas, the samples of emitted fly ash were taken as the test material. Particle size analysis of fly ash was performed using laser particle sizer Fritch Analysette 22. The PM10 share from all fly ashes from incineration of mixtures was about 100%. Differences were noted between PM2.5 and PM1.

Coke plants, which produce various types of coke (metallurgical, foundry or heating), at temperatures between 600 and 1200°C, with limited access to oxygen, are major emitters of particulates and gaseous pollutants to air, water and soils. Primarily, the process of wet quenching should be mentioned, as one of the most cumbersome. Atmospheric pollutants include particulates, tar substances, organic pollutants including B(a)P and many others. Pollutants are also formed from the decomposition of water used to quench coke (CO, phenol, HCN, H2S, NH3, cresol) and decomposition of hot coke in the first phase of quenching (CO, H2S, SO2) [1]. The development of the coke oven technology has resulted in the changes made to different types of technological installations, such as the use of baffles in quench towers, the removal of nitrogen oxides by selective NOx reduction, and the introduction of fabric filters for particulates removal. The BAT conclusions for coke plants [2] provide a methodology for the measurement of particulate emission from a wet, low-emission technology using Mohrhauer probes. The conclusions define the emission level for wet quenching process as 25 g/Mgcoke. The conducted research was aimed at verification of the presented method. For two of three quench towers (A and C) the requirements included in the BAT conclusions are not met and emissions amount to 87.34 and 61.35 g/Mgcoke respectively. The lowest particulates emission was recorded on the quench tower B and amounted to 22.5 g/Mgcoke, therefore not exceeding the requirements.

The physical properties of epoxy based carbon reinforced composites are highly anisotropic due to their directional structure and dependent on the manufacturing process parameters. Thermal conductivity was found to be dependent on the void volume fractions, which appear as a result of the insufficient vacuum level. In the proposed paper the multi-scale computational model of heat transfer across the carbon fiber-epoxy resin composite is proposed. The meso-scale effective thermal conductivities are determined with analytical formulae for isotropic and anisotropic media, the latter takes into account thermal resistance at the interface of fibres and epoxy resin. Proposed model is utilized to determine the effective thermal conductivity in the direction perpendicular to plies of composite. The influence of void fractions and the thickness of the composite on the effective thermal conductivity is investigated. The numerical outcomes underestimate the real variation in conductivity, which can be caused by change in carbon volume fraction of samples manufactured at different vacuum levels which was not considered in numerical computation.

The paper presents the results of thermodynamic and exhaust emission analyses of the combustion process using three combustion chambers. The combustion process research was performed on a single-cylinder AVL 5804 engine equipped with a dual-band compressed natural gas system supplied at different fuel pressures to the inlet channel and to the pre-chamber. Based on the performed analyses, the thermodynamic indicators of the combustion process and the emission factors were determined. Having the thermodynamic and emission analyses of the Turbulent Jet Ignition (TJI) combustion system, the pre-chamber was selected with the best collective features. The selection of the best chamber was made using the weighted-purpose method for average indicated pressure, CO and NOx emissions as well as the indicated engine efficiency, taking into account the impact factors.

Growing needs in transportation determinate systems development which improve efficiency of travel and reduce harmful influence to environment. Computational Fluid Dynamic (CFD) uses numerical analysis to find optimal solutions in terms of chosen objective function. Time save and reduce costs for experiments on prototypes are one of the advantages of this method. The aim of this research is to analyze airflow around different motor vehicles which are moving together in the same direction. To reduce fuel consumption and, at the same time, decrease negative influence to environment, the primary target was reducing total drag force during a ride. The vehicles were set in a column - one after another. In this work considered three types of vehicles: Car, Van and a Truck. Presented vehicles were organized into appropriate groups, creating different configuration. Additional parameter in simulation was distance between vehicles. Simulations of singular vehicles were also done. It allows to evaluate influence of moving vehicles in a column for generated drag force. Described traffic situation were modeled and numerically calculated using ANSYS® package. The purpose of this work was to assess the impact of the distance between vehicles, in a given configuration, for generated drag force.

In this paper, forced convection of water/EG-Al2O3 nanofluids inside horizontal stainless steel tube is studied experimentally. As base fluid served water/EG mixture of two ratios (60:50 and 50:50). Nanoparticle mass concentrations was 0.1% or and 1%. Transition and turbulent flow regimes were tested. Average heat transfer coefficient and pressure drop values were determined for nanofluids and compared to base fluids. Deterioration of heat transfer for all tested nanofluids has been recorded compared to base fluid. Negligible increase of pressure drop for nanofluids compared to base fluids has been observed.

Changes are inherent in activity of any enterprise. Several methods or concepts can be employed to introduce changes. One of the concept which has become popular recently and improves enterprise’s functioning is Lean Manufacturing. There are multiple techniques and tools which function within this method. Unfortunately, in the case of any changes, also in the case of implementation of Lean Manufacturing components, one can meet the resistance of employers and a number of technical and organizational problems. The aim of the paper is to collect and analyse information concerning the problems that occur during implementation of the Lean Manufacturing in Polish enterprises. The data were collected by means of a direct questionnaire survey. The results can be a suggestion for the enterprises which are planning to implement the Lean Manufacturing and indicate the problems they should be prepared for in the process.

The paper presents the initial approach to mathematical and numerical modelling and optimization of heat and mass transfer in elements of the masonry wall. The considered single moist brick is placed in the channel through which the dry air is flowing. Only one wall of the brick is in contact with the flowing air and through this boundary heat and moisture are exchanged. The non-equilibrium mathematical model is formulated for general case with three phases of moisture present in the porous building material, i.e., water vapour in the moist air filling the pores, liquid water (bound water) adsorbed at the surface of the solid component of the material and free liquid water either in a discontinuous form (funicular) or continuous one (pendular). However, at this stage of development of the numerical model the moisture in the form of motionless liquid water and water vapour which reside in the ceramic material are considered. Moreover, the moisture and heat diffusion in the porous hydroscopic material of the brick as well as moisture and heat convection in the flowing air are assumed. The numerical model is developed with the aid of the commercial software ANSYS Fluent and its advanced customisation functionalities like the User-Defined Function, User-Defined Scalar and User-Defined Memory. Subsequently, investigation of the influence of the mass transfer coefficient between the free liquid water and moist air in the porous building material are carried out.

The paper presents the results of analyzes of the granulometric composition of suspended solids in backwash water from biological activated carbon (BAC) filters and its changes during sedimentation. Backwash water samples were taken during backwashing of two pilot filters after different filtration time. It was found that regardless of the concentration of suspended solids in the collected backwash water, particle sizes vs. their percentage volume contributions for all samples were similar. Particle sizes were in the range of 2–100 μm. However, the two-hour sedimentation for most of the samples proved to be effective (total suspended solids removal up to 93%), which is caused by self-coagulation of the sample.

Increasing bicycle traffic causes the occurrence of related phenomena, which were not observed before. However, it can be observed that the cycling infrastructure of Warsaw is used in various ways, and some cyclists do not respect the law. The aim of this article is to examine the behaviour of cyclists in various road traffic situations. Empirical research was carried out for 15 objects located in Warsaw. Selected facilities were divided into 7 types of road infrastructure. The research was carried out by means of video recording with the use of a camera. Cyclists were classified by age, gender and type of bike used. As a result of the study, the number of correct and incorrect behaviours of cyclists was determined. It was found that the largest share of prohibited behaviours occurs in case of complicated solutions of cycling infrastructure and in case of its discontinuity. The behaviour of cyclists during the red signal display was also assessed. It was noted that this signal is better respected at road crossings than at tram crossings. Case studies have also been carried out and opportunities for improvement identified.

Opencast mining of large-area lignite deposits impacts the environment, and the health and life of people living in the vicinity of the conducted mining activity. Therefore, the attempt was made to develop a methodology for identification of environmental and social changes in the Bogatynia municipality (south-western Poland), resulting from functioning of Turow lignite mine within its area. During the study of changes occurring over the years, the development of mining pit was noticed, as well as the transformations of this area and impact of the mining plant on the selected elements of environment and surrounding areas. Analogue and digital data were used for the preparation of cartographic compilations, the usefulness of which was analyzed in accordance with the guidelines contained in the standard [1]. The conducted cartographic studies allowed to learn the history of the mine together with identification of changes taking place in the municipality Bogatynia. The obtained results show the form and condition of the objects in the analyzed year, allowing for the interpretation of changes that occurred in the surrounding areas of the Turow mine. Due to the conducted activity of the mine and Turow power plant, both negative and positive aspects were noted in connection with the carrying out of mining activity in the Bogatynia municipality.

Werenskiold Glacier in the Isle of Spitsbergen is one of the polygons on which evaluation of the rate of glacier recession is performed. Location of the glacier front is precisely presented in the specialist literature since the mid. 30. of 20th century. Article presents results of studies about changes in the position of Werenskiold Glacier based on selected archival data and own research conducted in 2012-2013. The initial location of the glacier front was described by the topographical map in the scale 1:5000 elaborated in the year 1961 on the basis of data from the years 1957-1959 by the Polish Army Topographic Service. Moreover, as comparative data on location of glacier front in the later years there were applied results of photogrammetrical images from the year 1973 and a orthophotomap from 1990. These data together with the author's GPS measurements were transformed into the uniform coordinate system. Thus, prepared data made it possible to evaluate the rate of recession of Werenskiold Glacier front in the three epochs from the years 1957-2013. It was found that during the 56 years the glacier front was moved by ca. 1200 m, which gives the mean recession value of 25 m/year as well as the mean yearly loss of the glacier surface of the order of 5 ha.

An inherent feature of Polish collieries within the Upper Silesia Coal Basin is the high level of mining induced seismicity, resulting in elevated rockburst hazard levels. One of the major causes of high-energy seismic events is that mining operations are continued in the vicinity of major faulting zones. The study summarises the results of geo-mechanical and statistical analysis of mining-induced seismic activity in the region of major faults, in a selected section within a colliery. Seismic activity assessment involves the categorisation of seismic events due to tectonic movements in the context of various face development systems with respect to the faulting zone: perpendicular (advancing towards the faulting zone or retreating) or parallel (along the faulting zone). Registered seismic activity was analysed in the context of epicenter locations and variations of seismic activity in relation to the developing face operations in the function of time and energy ratings (Gutenberg-Richter formulas). Results have demonstrated that increased levels of seismic activity in the strata can be attributable to mining operations in the vicinity of major faulting zones.

This paper presents thermal characteristics of prototype of a two-phase thermosyphon heat exchanger (TPTHEx) charged with acetone as a working fluid. The TPTHEx consists of two horizontal cylindrical vessels connected by two risers and a downcomer. Tube bundles placed in the lower and upper cylinders work as an evaporator and a condenser, respectively. The tested TPTHEx operates in a vacuum. Therefore, the working liquid is boiled in temperatures ranging from 33°C to 62°C. The overall heat transfer coefficient (OHTC) of the tested TPTHEx was estimated by the use of the Wilson method and the modified Peclet equation. The results obtained indicate a superiority of water over acetone as a working fluid. Moreover, it was shown that having a lower pressure in the shell-side of TPTHEx results in a higher overall heat transfer coefficient. The Wilson method and the modified Peclet equation predict OHTC with satisfactory agreement.

The paper presents development of the experimental stand for investigation of heating and drying phenomena in the porous building materials with one surface of the sample exposed to the flowing air. Moreover, results of preliminary measurements which verify the range of operating conditions achieved by the stand are shown. These conditions were assumed in the following range: 15℃-60℃, 10-90% and 0.1-10 m/s for temperature, relative humidity and velocity of the flowing air, respectively. In order to control the parameters of air used for heating and drying of porous materials, a closed-loop concept of the stand was proposed and equipped with several elements, i.e., the cooler (vapour condenser), fan with variable rotational speed, humidifier and heater. Furthermore, two parallel measurement ducts which allow to obtain two air streams with identical parameters were proposed. This enables two measurements at one time as well as faster verification of the repeatability of the performed measurements. The temperature measurements at the top surface and inside the sample are carried out applying the IR thermography and several K-type thermocouples, respectively, while overall moisture amount and the moisture content distribution in the specimen are found using tensometric force and electrical resistance meters, respectively.

Detailed and reliable design of a photovoltaic (PV) power plant cannot be underestimated. In terms of energy production forecasts and legal issues concerning financing - simulation performance of the PV installation is a very important problem for both the investor and the bank. In order to simulate the performance of the PV system one has to choose proper meteorological database which would be the most reliable on the installation site. Since different meteorological databases have different measurements methods and analysis, choosing the best one is not a trivial problem. In order to find the best meteorological data source for PV simulation performance under eastern Poland conditions, PVSYST software has been used. Detailed project of an 1.39 MWp PV power plant located in Bordzilowka in the east of Poland was introduced into the software. Choosing different meteorological data bases, monthly and yearly energy production was established. The simulation results were compared with the real data obtained from the PV power plant.

In the article the elaborated simulation and experimental models of the power electronics UPS converter with the possibility of active parallel compensation were described. The power circuits, control algorithms and the principle of working of presented UPS structure were presented. Also the chosen simulation and experimental results were analyzed.

Widespread in Polish hard coal mining, cable bolts are used to reinforce the arch yielding support of roadways. This article attempts to prove that change in approach to long bolting technology can bring significant benefits in terms of improving the stability of roadways, including limiting the development of the fracturing zone in the roof, and ultimately also increasing the frame spacing of arch yielding support. The article contains the results of numerical calculations using the finite element method showing the effect of pre-tensioning on the work of cable bolts installed in a situation when a zone of a fractured rock mass appeared in a roof excavation. As a result of the calculations, the dependence of the final vertical displacements of the roadways roof on different pre-tensioning variants of the cable bolts was presented. The second part of the article presents the practical aspects of the use of cable bolts with pre-tensioning in reinforcing the rock mass and arch yielding support of roadways. In addition, the article identifies the developments in bolting technology which could lead to an increase in work safety and reduce the costs of arch yielding support.

The paper presents a motorcycle dynamics model developed for testing and future model based controller designs for accelerated maneuvers on variable slip terrains. The dynamics is simplified, yet it captures real motorcycle behaviors when it accelerates and decelerates on a curvy trajectory and contact forces due to variable ground properties change and allow to generate slip. The tire - terrain model is based upon a simplified Pacejka model. The paper objective is not to obtain complex dynamical systems of equations like those required for high-fidelity simulations. Instead, the aim is to derive simple but reliable and manageable models that enable designing and implementing, and verifying control laws, as well as maintaining their capability to capture the main behaviors of real systems. The paper applies the adopted assumptions to develop the motorcycle model, and presents simulation tests for the motorcycle acceleration and deceleration during turn maneuvers, and during changes of the ground the vehicle moves on.

Sewage sludge contains organic and biogenic substances that should be used. These materials may also contain toxic substances and heavy metals, and therefore require proper management in accordance with applicable law. Sewage sludge disposal is important for the protection of the environment, but also for the costs associated with the disposal of sludge. There are many technologies that are designed to use the properties of sewage sludge. It should be emphasized, however, that the proposed sewage sludge management technologies require investment outlays. In the present situation, research experiments have been carried out in the Environmental Technology Laboratory of the University of Environmental and Life Sciences in Poznan, indicating the possibility of efficient use of sewage sludge in the methane fermentation process. The use of sewage sludge in the fermentation mix allows the fertilizer to be obtained in the form of fermentation pulp, which also has the same properties as natural fertilizers. It should also be noted that the effect of physicochemical changes is the production of biogas, which is the source of electricity and/or heat. The economic sustainability of the use of sludge (taking into account the current costs of their disposal) is unequivocally positive when co-fermented in an appropriate proportion. The results show that sewage sludge can be successfully used in biogas plants as a co-substrate of fermentation mix. Therefore, the use of sewage sludge in biogas plants not only allows for the safe management and production of fertilizers, but also for the "green" energy.

Along with the development of environmental friendly technologies, an increasing interest in generating the electricity and heat from renewable sources has been observed in Poland. Perfect example of such installations are agricultural biogas plants, where methane fermentation produces high-energy gas fuel i.e. biogas. Before investing, it is necessary to perform a detailed studies of the biogas efficiency of the substrates used. The proper run of fermentation process, as well as the high biogas production related to the operation, depend on many factors, including the mixing inside the reactor. The DIN 38 414-S8 standard, commonly used in the tests, assumes the mixing of the whole eudiometric sets, used in accredited laboratory units, which due to their uniform construction may cause problems. The aim of the study was to determine the effect of laboratory mixing in the fermentation reactor on the biogas efficiency of the maize straw. The experiment tests were performed in the Laboratory of Ecotechnologies, in the Poznan, in accordance with the current standard DIN 38 414-S8.The obtained research results confirmed the effect of mixing inside the fermentation reactors on the biogas efficiency of the maize straw.

Recent studies of η nuclear quasibound states by the Jerusalem-Prague Collaboration are reviewed, focusing on stochastic variational method self consistent calculations of η few-nucleon systems. These calculations suggest that a minimum value Re aηN ≈ 1 fm (0.7 fm) is needed to bind η3He (η4He).

In this contribution we extend the recently developed two-flavor quark-matter string-flip model by including strange quarks. We discuss implications for compact stars.

The γ-coincidence studies of low-spin structures of 210Bi and 206Tl are presented. The 210Bi nucleus, populated in thermal neutron capture reaction, was investigated using EXILL HPGe array at Institut Laue-Langevin in Grenoble. The experimental results were compared to the shell-model calculations allowing to draw the conclusions on the nature of the low-spin excitations populated below the neutron binding energy in 210Bi (4.6 MeV). It has been found that some levels cannot be described by the valence proton and neutron couplings, but may arise from couplings of valence particles to the 3- octupole phonon of the doubly magic 208Pb core. Moreover, preliminary results of a low-spin structure measurements of 206Tl by the γ-coincidence technique, making use of the 205Tl(n,γ)206Tl reaction at the FIPPS prompt γ-ray spectroscopy facility of ILL are shown. The population of a large number of excited states of 206Tl above the ground state up to the neutron binding energy (at 6.5 MeV), within a few units of spin is expected. The analysis involving double and triple γ-coincidences and γγ-angular correlations will allow to significantly extend the experimental information on the energy and spin-parity of the levels in 206Tl. This will help shedding light on the proton-hole and neutron-hole couplings near the doubly magic core 208Pb.