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Abstract

The paper presents a proposal for the assessment of the reliability of steel truss (both statically determinate and indeterminate) in the persistent and accidental design situation. In the analysis, a probabilistic approach was used. The global Hasofer-Lind reliability index was employed, computed in successive time steps for the whole structure, not for individual elements. The statically determinate truss was modelled as a serial system from the reliability standpoint. For the statically indeterminate truss, kinematically admissible failure mechanisms were determined by means of the examination of the singularity of the stiffness matrix of the structure, converting the truss into a geometrically variable system. For the problem thus formulated, a serial-parallel reliability model was constructed. Monitoring the reliability index in the successive minutes of the fire makes it possible to estimate the probability of the structure failure, and to decide whether the required safety level is maintained.

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Authors and Affiliations

K. Kubicka
U. Radoń
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Abstract

The term Pakoszówka-Bessów type pottery is used to describe a specific kind of wheelmade pottery with easily abradable surfaces mostly dated to the 3rd century AD. Site 3 in Bessów, Bochnia Commune, Lesser Poland, is located in the dense Przeworsk culture settlement micro-region occupying the right bank of the lower reaches of the Raba River. The most characteristic feature of locally produced artefacts from Bessów, and to a lesser extent from other sites in the region, is the presence of enormous amounts of this pottery. The aim of laboratory analyses carried out on Pakoszówka-Bessów type pottery from Bessów was to verify the hypothesis that abradability of sherd surfaces is attributable to the alteration effect.

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Authors and Affiliations

Magdalena Okońska
Małgorzata Daszkiewicz
Ewa Bobryk
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Abstract

The purpose of the work was to determine the relationship between the of the water quality parameters in an artificial reservoir used as cooling ponds. Multivariate methods, cluster analysis and factor analysis were applied to analyze eighteen physico-chemical parameters such as air and water temperature, dissolved oxygen concentration, visibility of the Secchi disk, concentrations of total nitrogen, ammonium, nitrate, nitrite, total phosphorus, phosphate, concentrations of calcium, magnesium, chlorides, sulfates and total dissolved salts, pH, chemical oxygen demand and electric conductivity from 2002-2017 to investigated cooling water discharge. Hierarchical cluster analysis (CA) allowed identified five different clusters that reflect the different water quality characteristics of the water system. Similar results were obtained in exploratory factor analysis, five factors were obtained with 65.96% total variance. However, confirmatory factor analysis showed that four latent variables: salinity, temperature, eutrophication, and ammonia provide better fit to the data than a five-factor structure. Correlations between latent variables temperature, eutrophication and ammonia show a significant effect of temperature on the transformation of nitrogen and phosphorus compounds.
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Authors and Affiliations

Jerzy Mazierski
1
Maciej Kostecki
1
ORCID: ORCID

  1. Institute of Environmental Engineering, Polish Academy of Sciences, Poland
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Abstract

The paper concerns the accuracy of determining particle size distributions of the fine-grained materials by means of laser diffraction method. Selection of measuring method for determination of materials granulation depends on various properties of the sample, but mainly on the range of particle size in the sample. It must be taken into consideration that each of the measurement methods inherently generate different information about particle size distribution. The applied measurement method generates the main impact on the results of research because it uses various material properties, like: geometric properties, density or type of the surface (porosity).

Influence of density and particle shape on the results of measurements by laser diffraction was studied in the paper. This method becomes a standard for measuring particle size of mineral powders. Analysis of raw materials particle size distribution was performed using a laser particle-meter Analysette 22. Investigations included measurements of particle size of raw materials characterized by various densities (coal, porphyry, barite) and the shape of the particles (copper shale ore, fly ash from coal combustion). The density of raw materials was determined by helium pycnometer, while the particle shape was expressed by coefficient which was calculated on the basis of particles geometric parameters. Geometry of the grains was measured using an optical microscope with a digital record of images by means of image analysis method. The accuracy of laser granulometric analyzes was expressed by variation coefficient of narrow particle fractions contents. Results of analyzes confirmed that the laser granulometric analysis provides accurate information about the finestparticle size distribution. No significant effect of the material density on the accuracy of granulometric analysis was observed. Effect of particle shape of the tested materials caused more stable values of the variation coefficient for particles of more spherical shape what is related to the applied method of laser measurement. The accuracy of laser granulometric analyzes varies dependably on the measured particle size range of particles. The most accurate analyzed materials are these ones being the part of narrow particle fractions.

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Authors and Affiliations

Damian Krawczykowski
Aldona Krawczykowska
Kazimierz Trybalski
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Abstract

The paper deals with examination of financial profitability of the introduction of rainwater utilization system (RWUS) in multi-family residential buildings. The aim of the work was to build a simulation model of such system and mak_e an LCC analysis of some options of rainwater utilization system. The proposed conception of a new method of selecting the most cost-effective option of RWUS includes: building of simulation model of such system, making the LCC analysis and using a scenario analysis for supporting decision making process with uncertainty. This new method has been applied to a dwelling house in Poland. The results obtained from the analysis demonstrate the unprofitabiliry of the introduction o fRWUS in multi-family residential buildings for the adopted location in Poland. The presented method can be used by individual designers and managers to decide on the selection of the most appropriate water supplying option for a specific location.
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Authors and Affiliations

Daniel Słyś
Tadeusz Bewszko
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Abstract

Determining the level of solid pollution in beach sands located near artificial inland water bodies in order to maintain high safety standards is a difficult and expensive task. The tests aimed at determining beach pollution caused by solid wastes through analysis of toxic and chemical concentrations, are time-consuming and usually require several days before the results are available. In addition, the maintenance of the beach area involving beach raking or grooming, and the seasonal replenishment of sand makes it difficult to realistically determine the chemical or bacterial contamination of the tested material. Solid pollutants, such as glass, caps, cans, thick foil, metal, and plastic fragments, pose a greater health risk to beachgoers. The above-mentioned pollutants, especially small ones, are hardly visible on the surface or they are buried at shallow depths. Beach garbage poses a serious threat that can lead to infections from cuts and scratches. These injuries can become infected, further jeopardizing the health and lives of beachgoers due to risks like tetanus, staphylococcus, etc. The authors presented a new petrographic method aimed at assessing the quality of sand by examining the content of solid pollutants. The obtained results allowed us to conclude that the mentioned procedure can be used for a quick quantitative estimation of the content of potentially dangerous and undesirable pollutants in beach sands. Consequently, the method implemented to determent the amount of solid pollutants in beach sands has proven to be a valuable tool for recreational facility administrators, helping them in taking necessary measures to ensure the safety of beach users. Petrographic analysis of beach sands revealed the presence of pollutants of plant origin (0.4–1.8%), plastic (0.1–0.4%), paper (0.1–0.6%), charcoal (0.1–0.5%), glass (0.1–0.4%), metals (0.1–0.4%), rust (0.1–0.3%), ash and slag (0.1–0.3%), and fossil coals (0.1–0.2%).
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  19. Şanlıtürk, G. & Güran M. (2021). Monitoring of microbiological dynamics in beach sand and seawater samples from recreational and non-recreational beaches over a two-year period. International Journal of Environmental Health Research. pp.1-13. DOI:10.1080/09603123.2021.1931049
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Authors and Affiliations

Sebastian Kuś
1
ORCID: ORCID
Zbigniew Jelonek
1
ORCID: ORCID
Iwona Jelonek
1
ORCID: ORCID
Edyta Sierka
1
ORCID: ORCID

  1. University of Silesia in Katowice, Poland
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Abstract

The selection of the formwork system for high rise building affects the entire construction project duration and cost. The study reports the factors influencing the selection of different formwork system in the construction of high rise buildings through structural questionnaire survey from the client, contractor, consultant, and interviews with expert members. Total of 40 technical factors was identified from the literature and 220 filled questionnaires were received from the respondent. Relative Importance Index method is used to find the topmost factors affecting the selection of formwork system. Additionally, from factor analysis 22 factors were identified to have a correlation with one another. Regression analysis reveals that duration of the project, maintenance cost, adaptability, and safety have impact on formwork selection across time, cost and quality. These findings could potentially increase the construction company’s existing knowledge in relation to formwork selection.

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Authors and Affiliations

Viswanathan Rajeshkumar
V. Sreevidya
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Abstract

The volume of combustion chamber consists of head and cylinder spaces. The distribution of volumes in the cylinder depends on accuracy of dimensions, determined by the production process, and precision of the crankshaft system assembling. Therefore, the aim of this work is to present a correct method of assembling, and give an example of analysis of crankshaft system dimensions based on the engine family type Wola-135TC.
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Authors and Affiliations

Józef Jezierski
Marek Kowalik
Zbigniew Siemiątkowski
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Abstract

Thermodynamics deals with irreversible transformations of substances. Every thermodynamic property of a substance, as a function of two parameters describing its state, can be illustrated as a simply connected manifold. The term manifold stands for the Methods of Geometrical Representation of Thermodynamic Properties of Substances by Means of Surfaces. Generally, every transformation of a substance changes its energy (or enthalpy) by heat transfer and work done on it. All such changes (transformations) are considered to be irreversible and can be described using appropriate manifolds. Studies show that every transformation is associated with the degradation of energy. Such relations (between heat, work and other forms of energy or enthalpy) can be described by the Pfaff formulas and their integrations.

This article discusses the issue of irreversible energy degradation in heat transfer between two fluids. Irreversible heat transfer between separated fluids most often occurs through surface heat exchangers. All such processes are determined by convective heat transfer in thermal boundary layers and conduction through the wall. Consequently, entropy changes of fluids in heat and mass transfer can be observed in these layers. While the entropy rate of the heating fluid is negative and that of the heated medium is positive, the sum of entropy changes of all substances involved in the heat transfer process is always positive. These sums, known as entropy increase (entropy generation), can be interpreted as the measure of irreversible degradation of energy in heat transfer processes. The consequence of this degradation is that an arbitrary engine powered by the degraded (lower-temperature) heat flux will operate at a lower efficiency. The significance of this discussion relates especially to cases in power plants and cooling systems where surface heat exchangers are used. In the discussion proposed is the entropy increase as a criterion of irreversible energy degradation in heat transfer. Such introduced measure of effectiveness leads to an analysis of local overall heat transfer coefficient optimization on the cone-shaped manifold.

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Authors and Affiliations

Zbigniew Drożyński
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Abstract

Introduction: Osteoporosis affects over 200 million people worldwide causing nearly 9 mil-lion fractures annually, with more than half in America and Europe.
Objectives: This meta-analysis was conducted to investigate whether low milk intake is associated with an increased risk of fractures by summarizing all the available evidence.
Methods: Relevant studies were identified by searching the PubMed and EMBASE databases up to June 2020. The pooled relative risks with 95% confidence intervals were calculated.
Results: In a meta-regression analysis of 20 included studies (11 cohort and 9 case-control studies), a higher milk intake was not associated with a reduction in the total fracture risk in both sexes (OR 0.95, 95% CI: 0.84– 1.08), either in cohort (OR 0.91; 95% CI: 0.79–1.05) or case-control studies (OR 1.09; 95% CI: 0.82–1.44), as well as separately in men (OR 0.87; 95% CI: 0.71–1.07) and women (OR 0.95; 95% CI: 0.80–1.13).
Conclusion: Higher milk consumption is not associated with fracture risk reduction and should not be recommended for fracture prevention.
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Authors and Affiliations

Grzegorz Goncerz
1 2
Patrycja Kojm
3
Sylwia Skocelas
3
Krzysztof Więckowski
3
Tomasz Gallina
3
Paulina Pietrzyk
3
Sebastian Goncerz
3

  1. Department of Anatomy, Jagiellonian University Medical College, Kraków, Poland
  2. Polish Institute of Evidence Based Medicine, Kraków, Poland
  3. Jagiellonian University Medical College, Kraków, Poland
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Abstract

The paper presents a new kind of vibrator, called the intelligent vibrator, which is an integrated set of two inert vibrators supplied by asynchronous squirrel-cage motors, equipped with digital control system, the readout system of the position of unbalanced masses, and inverter supply system. The paper presents a model of the prototype of the machine and exemplary run-times.
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Authors and Affiliations

Mariusz Giergiel
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Abstract

Choral singers are among intensive voice users whose excessive vocal effort puts them at risk of developing voice disorders. The aim of the work was to assess voice quality for choral singers in the choir at the Polish-Japanese Academy of Information Technology. This evaluation was carried out using the acoustic parameters from the COVAREP (A Collaborative Voice Analysis Repository For Speech Technologies) repository. A prototype of a mobile application was also prepared to allow the calculation of these parameters.

The study group comprised 6 male and 19 female choir singers. The control group consisted of healthy non-singing individuals, 50 men and 39 women. Auditory perceptual assessment (using the RBH scale) as well as acoustic analysis were used to test the voice quality of all the participants. The voice quality of the female choir singers proved to be normal in comparison with the control group.

The male choir singers were found to have tense voice in comparison with the controls. The parameters which proved most effective for voice evaluation were Peak Slope and Normalized Amplitude Quotient.

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Authors and Affiliations

Krzysztof Szklanny
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Abstract

Monitoring the solidification process is of great importance for understanding the quality of the melt, for controlling it, and for predicting the true properties of the alloy. Solidification is accompanied by the development of heat, the magnitude of which depends on the different phases occurring during solidification. Thermal analysis is now an important part of and tool for quality control, especially when using secondary aluminium alloys in the automotive industry. The effect of remelting on the change of crystallization of individual structural components of experimental AlSi9Cu3 alloy was determined by evaluation of cooling curves and their first derivatives. Structural analysis was evaluated using a scanning electron microscope. The effect of remelting was manifested especially in nucleation of phases rich in iron and copper. An increasing number of remelts had a negative effect after the fourth remelting, when harmful iron phases appeared in the structure in much larger dimensions.

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Authors and Affiliations

M. Matejka
ORCID: ORCID
D. Bolibruchova
Justyna Kasińska
ORCID: ORCID
M. Kuriš
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Abstract

The aim of this study was to compare computer assisted sperm analysis (CASA) results of frozen thawed bull semen using three different chambers. Sixty bull frozen semen samples were thawed (37°C; 30 sec), extended in PBS (30×106 spermatozoa/mL; 37°C) and incubated (37°C; 2 min). Each semen sample was analyzed by CASA [total motility, progressive (pro)/ non-progressive/rapid/medium/slow movement spermatozoa, VCL, VSL, VAP, ALH, BCF, LIN, STR, WOB and hyperactive spermatozoa] using three different chambers: a Makler® chamber (MC; 10 μm); a Leja 4 chamber slide (LC; 20 μm); and a Glass slide covered with a coverslip (GSC; 10.3 μm). The Makler chamber gave higher values compared to both the LC and GSC for almost all examined parameters. No systematic effect was evident between LC and GSC for VCL, VSL, VAP, LIN, STR, WOB, ALH, and BCF. Method agreement between MC and LC was generally moderate, between MC and GSC poor and between LC and GSC moderate to good. In general, narrower limits of agreement were found in samples with lower values. In conclusion, the CASA outcomes could be influenced by the analysis chambers. This finding should be taken into consideration when comparing results from different laboratories.

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Authors and Affiliations

A. Basioura
G. Tsousis
C. Boscos
A. Lymberopoulos
I. Tsakmakidis
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Abstract

The progress of additive manufacturing technology brings about many new questions and challenges. Additive manufacturing technology allows for designing machine elements with smaller mass, but at the same time with the same stiffness and stress loading capacity. By using additive manufacturing it is possible to produce gears in the form of shell shape with infill inside. This study is carried out as an attempt to answer the question which type of infill, and with how much density, is optimal for a spur gear tooth to ensure the best stiffness and stress loading capacity. An analysis is performed using numerical finite element method. Two new infill structures are proposed: triangular infill with five different densities and topology infill designed according to the already known results for 2D cantilever topology optimization, known as Michell structures. The von Mises stress, displacements and bending stiffness are analyzed for full body gear tooth and for shell body gear tooth with above mentioned types of infill structure.

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Authors and Affiliations

A.J. Muminovic
M. Colic
E. Mesic
I. Saric
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Abstract

The main objective of this work is to present an innovative method of numerical modeling of anchored piles system acting as a road protection against landslide, called the “2D/3D method”. Firstly, short description of the problem and “state of the art” review are included. An effective methodology of the design supported by the numerical analysis, solving the problem of interaction of a periodic system of piles and the unstable soil mass is presented, for which some detailed information about proposed numerical approach is given. The key idea of 2D/3D method is to join the pile with the 2D plane strain continuum by fictitious connectors of Winkler type with P-Y properties identified during the analysis of a subsidiary 3D problem. Practical example of usage of proposed approach to a real case of a road endangered by a landslide then protected by the piles system is presented. On the base of this example, a discussion about important design issues like internal forces in piles (mainly bending moments) and anchors (tensile forces) or overall stability of the soil-structure system is done.

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Authors and Affiliations

A. Urbański
M. Grodecki
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Abstract

The objective of this paper is to develop a Non Destructive Testing (NDT) method for the detection and classification of defects in composite materials at a micro level and to devise methodologies to analyse the corrosion resistance behavior using Scanned Electron Microscope (SEM) imagery. The defects on the Stainless Steel – Molybdenum (SS-Mo) Nanocomposite coating is estimated from their Scanning Electron Micrographs by using Image Processing algorithms. For this, the SS-Mo Nano Composite coatings are fabricated using a DC magnetron sputtering process using an indigenously prepared sputtering target. Depositions are carried out on Glass substrate for the evaluation of structural, morphological, chemical composition and corrosion resistance of the coatings prepared under different conditions (deposition of SS at 300°C and RT (Room Temperature); deposition of SS + Mo at 300°C and RT). The structural and compositional analysis performed with X-ray Diffraction (XRD) and Energy-Dispersive X-ray spectroscopy (EDX) has confirmed the formation of Stainless Steel Molybdenum Composite, when the deposition is at 300°C. The SS-Mo composite deposited at 300°C is also observed to yield high corrosion resistance of the order 0.058 mm/year. A novel texture – morphology based image feature descriptor has been proposed for corrosion resistance to evaluate the composite material in a Non-destructive manner. The analysis of SEM image of the developed coatings using the proposed feature along with machine learning algorithm reveals the superior property for SS-Mo coatings deposited at 300°C which is also demonstrated by the laboratory experiments.
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Authors and Affiliations

M.C. Pravin
1
ORCID: ORCID
S. Karthikeyan
2
ORCID: ORCID
S. Sathyabama
3
ORCID: ORCID
Sivaramakrishnan Balaji
4
ORCID: ORCID

  1. Bannari Amman Institute Of Technology, Mechatr Onics, India
  2. Thiagarajar College of Engineering, Mechanical Engineering, India
  3. Thiagarajar College of Engineering, Electronics and Communication Engineering, India
  4. Thiagarajar College of Engineering, Chemistry, India
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Abstract

FMEAs have been prioritized using RPN; however, a new standard has introduced AP for prioritization. This study seeks to determine if the number of required improvement actions increases, decreases, or stays the same when using AP in place of RPN. Statistical software was used to simulate 10,000 combinations of severity, occurrence, and detection. Both AP and RPN were calculated for the 10,000 combinations. Statistical hypothesis testing was performed to determine if there was a difference between RPNs when sorted by AP and to determine if there was a difference in actions required using RPN or AP. There is a statistically significant difference between RPNs when sorted by high, medium, and low AP. Using an RPN threshold equal to or greater than 100 would result in no change in the number of actions required if prioritizing by high and medium, but would result in fewer actions required if only high is used.
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Authors and Affiliations

Matthew Barsalou
1
ORCID: ORCID

  1. Automotive Industry, Germany
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Abstract

Pollen morphology of Polygala taxa from the family Polygalaceae in Turkey is presented in this study. Pollen features of 18 species along with one undescribed species in the section Polygala were examined with light and scanning electron microscopy, 11 of which were studied and defined for the first time. Cluster analysis and principal components analysis were conducted to determine informative palynological characters and to discover similarities among the studied taxa. Based on qualitative and quantitative variables in the phenogram, the studied taxa were divided into three major clusters. Multivariate analyses revealed that apocolpium characters, including a psilate apocolpium, the presence of apocolpial lumens with granules and small depressions with psilate or rugulate walls are the most distinct features for discriminating Polygala taxa. Intraspecific variations in some pollen characters, such as the exine pattern and aperture membrane features, are reported for several taxa. Pollen morphological data obtained in the present study are compared with those from previous studies for a number of species, and the results are evaluated. In addition, the aperture number and its probable significance in the Turkish Polygala are considered for some taxa, with emphasis on their known pollination strategies.
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Authors and Affiliations

Emel Oybak Dönmez
1
Zübeyde Uğurlu Aydın
1
Ali A. Dönmez
1

  1. Hacettepe University, Faculty of Science, Department of Biology, Beytepe, Ankara, Turkey
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Abstract

The dynamic analyses are of key importance in the cognitive process in terms of the correct operation of structures loaded with time alternating forces. The development of vehicle industry, which directly results in an increase in the speed of moving vehicles, forces the design of engineering structures that ensure their safe use. The authors of the paper verified the influence of speed and vehicle parameters such as mass, width of track of wheels and their number on the values of displacements and accelerations of selected bridge elements. The problem was treated as the case study, because the analyses were made for one bridge and the passage of three types of locomotives. The response of the structure depends on the technological solutions adopted in the bridge, its technical condition, as well as the quotient of the length of the object and vehicle. A new bridge structure was analyzed and dynamic tests were carried out for trainsets consisting of one and two locomotives. During the actual dynamic tests, the structure was loaded with a locomotive moving at a maximum speed of 160 km/h.

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Authors and Affiliations

Michał Jukowski
Artur Zbiciak
ORCID: ORCID
Bartosz Skulski
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Abstract

The paper presents the determination of the impact of earthquakes of varying intensity on the structure of geodesic domes. The structures of the analyzed domes were designed on the basis of the regular octahedron according to two different methods of creating their topology. The use of four seismic records of different intensity and duration of the record made it possible to subject 8 models to numerical analysis. The designed spatial structures are domes with a steel cross-section, thanks to which they are undoubtedly characterized by their lightness and the possibility of covering very large areas, without the need to use internal supports. Designing steel domes is currently a challenge for constructors, as well as architect, who take into account their aesthetic considerations. The paper presents the seismic response of geodesic domes in applied different directions (two horizontal “X” and “Y” and one vertical “Z”), using the Time History method. The values of forced vibrations and recording intensity were shown, and on this basis, an attempt was made to determine which seismic record may be more unfavorable for the designed geodesic domes created according to two different methods of shaping the topology of their structures. For this purpose, the FFT (Fast Fourier Transform) method was used. The maximum accelerations and displacements of the structures were also analyzed. The conducted analysis shows the influence of seismic excitations on geodetic dome structures, depending on the applied method (method 1 and 2) of shaping their topology. This paper will undoubtedly be useful in designing a geodesic dome structure in a seismic area. In addition, this analysis can be helpful in assessing the effects of an incidental earthquake.
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Authors and Affiliations

Dominika Bysiec
1
ORCID: ORCID
Tomasz Maleska
1
ORCID: ORCID

  1. Opole University of Technology, Faculty of Civil Engineering and Architecture
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Abstract

This paper presents the results of palaeobotanical studies (pollen and plant macrofossil analyses) of the sediments from the profile Michałowo P-3 (Gródek-Michałowo Depression, NE Poland). At this profile the second bed of peat under Holocene peat and the layer of silts and sands was discovered. The pollen succession indicates that they were deposited, with some gaps, from the beginning of Eernian Interglacial to Early Vistulian. The local pollen zones, distinguished in the pollen diagram, correlate with the regional pollen stratigraphy of the Eemian Interglacial, but the pollen record of hornbeam (ES R PAZ) and spruce (E6 R PAZ) regional zones is absent in Michałowo. In the middle part of the Michałowo pine zone (Mi-5 Pinus L PAZ), a cool oscillation of climate is marked by an opening of forests and development of herb plant communities.
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Authors and Affiliations

Mirosława Kupryjanowicz
Danuta Drzymulska
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Abstract

Exploitation of hard coal seams by roadway system is applied by two coal mines in southern Poland in Upper Silesian Basin. It is a secondary mining exploitation carries out in safety pillars of urban areas and shafts within mining areas of closed coal mines. Roadway system is the excavation process of gateways which are made in parallel order leaving coal pillars between them. An optimal width of coal pillar makes roadway stable and reduces subsidence of terrain surface. The article presents results of subsidence simulation caused by partial extraction using empirical and numerical methods on the example of one exploitation field of “Siltech” coal mine. The asymptotic state of subsidence was considered after mining ceased in the study area. In order to simulate of subsidence, numerical model of rock mass and model of Knothe-Budryk theory were calibrated. Simulation of vertical displacements in numerical method was carried out using RS3 program by Rocscience based on finite element method. The assumption was made that model of rock mass is transversely isotropic medium, in which panels were designed according to order of extraction of coal seams. The results of empirical and numerical methods were compared with measured values of subsidence at benchmarks along drawn lines (subsidence profiles).

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Authors and Affiliations

Piotr Polanin
Andrzej Kowalski
ORCID: ORCID
Andrzej Walentek
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Abstract

Geothermal waters are a source of clean energy. They should be used in a rational manner especially in energyand economic terms.

Key factors that determine the conditions in which geothermal waters are used, the amount of energy obtainedand the manner in which cooled water is utilised include water salinity. Elevated salinity levels and the presence oftoxic microelements may often lead to difficulties related to the utilisation of spent waters. Only a few Polishgeothermal facilities operate in a closed system, where the water is injected back into the formation after havingbeen used. Open (with water dumped into surface waterways or sewerage systems) or mixed (only part of the wateris re-injected into the formation via absorption wells while the rest is dumped into rivers) arrangements are morefrequently used. In certain circumstances, the use of desalinated geothermal water may constitute an alternativeenabling local needs for fresh water to be met (e.g. drinking water).

The assessment of the feasibility of implementing the water desalination process on an industrial scale islargely dependent on the method and possibility of disposing of, or utilising, the concentrate. Due to environmentalconsiderations, injecting the concentrate back into the formation is the preferable solution. The energy efficiency and economic analysis conducted demonstrated that the cost effectiveness of implementing the desalinationprocess in a geothermal system on an industrial scale largely depends on the factors related to its operation,including without limitation the amount of geothermal water extracted, water salinity, the absorption parameters ofthe wells used to inject water back into the formation, the scale of problems related to the disposal of cooled water,local demand for drinking and household water, etc. The decrease in the pressure required to inject water into theformation as well as the reduction in the stream of the water injected are among the key cost-effectiveness factors.Ensuring favourable desalinated water sale terms (price/quantity) is also a very important consideration owing tothe electrical power required to conduct the desalination process

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Authors and Affiliations

Barbara Tomaszewska
ORCID: ORCID
Leszek Pająk
ORCID: ORCID

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