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Statistical Description of Diffraction Pattern of Aperiodic Crystals

J. Wolny I. Bugański L. Pytlik R. Strzałka
Archives of Metallurgy and Materials | 2019 | vol. 64 | No 2 | 721-725 | DOI: 10.24425/amm.2019.127604
Keywords aperiodic systems quasicrystals modulated crystals statistical method
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Abstract

Modern crystallography faces a demanding challenge of describing atomic structure and diffraction pattern of quasicrystals, which, after 30 years of Shechtman’s discovery, is still an open field of research. The classical approach based on the Braggs and Laue equations in three-dimensional space is useless, because the direct and the reciprocal lattices cannot be introduced for aperiodic systems. A standard solution to this problem, applied by number of scientists, is to retrieve periodicity in high dimensions. This is a purely mathematical approach with some difficulties from a point of view of physics. It is mathematically elegant, but not applicable to all aperiodic systems (e.g. Thue-Morse or Rudin-Shapiro sequences). It meets also a serious trouble in a proper description of structural defects, like phasons. In our opinion the most successful alternative to the multidimensional description is a statistical method of diffractional and structural analysis of aperiodic systems, also known as the average unit cell approach (AUC). In this work an application of the AUC method to selected aperiodic systems, including modulated structures, quasicrystals and covering clusters, is discussed in the form of a mini-review. A reader can find more details in the cited references.

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Authors and Affiliations

J. Wolny
I. Bugański
L. Pytlik
R. Strzałka

The Adjustment of the Tundish Water Model of Continuous Casting

P. Blaško B. Bulko J. Petrík P. Demeter V. Socha L. Hanáková P. Palfy M. Solc A. Vasilňáková
Archives of Metallurgy and Materials | 2022 | vol. 67 | No 1 | 97-104 | DOI: 10.24425/amm.2022.137477
Keywords steel tundish water model continuous casting statistical methods
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Abstract

Whereas approximately 96.3% of the steel produced worldwide is made by continuous casting, great emphasis is put on the superior efficiency of this process. The water model of the tundish and mathematical modeling is often used for the simulation of the steel flow during continuous casting. The experiments were performed on a model of the tundish with two outlets, at two casting speeds (0.8 m.s–1 and 1.2 m.s–1). Eight setups of the tundish were evaluated, which differed in the design of the dams (with or without drainage holes), in their distance from the center of the tundish, and their height. The contribution of the work is the analysis of phenomena in the tundish water model in conditions of repeatability (ten repetitions). The goal is to find the setup providing the most symmetrical flow, with the minimum difference in the residence times Δτ on the two outlets. Taking into account the results obtained at both casting speeds, the most preferred is setup 2 with the 87 mm high dams placed 587 mm from the center of tundish (Δτ = 0.5). The setup 3 (Δτ = 8.25) appears to be the least appropriate. The higher the casting speed, the higher the number of unsuitable arrangements.
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Authors and Affiliations

P. Blaško
1
ORCID: ORCID
B. Bulko
1
ORCID: ORCID
J. Petrík
1
ORCID: ORCID
P. Demeter
1
ORCID: ORCID
V. Socha
2
ORCID: ORCID
L. Hanáková
2
ORCID: ORCID
P. Palfy
1
ORCID: ORCID
M. Solc
1
ORCID: ORCID
A. Vasilňáková
1
ORCID: ORCID
  1. Technical University of Košice, Faculty of Materials, Metallurgy and Recycling, Letná 9, 04 001 Košice, Slovakia
  2. Czech Technical University in Prague, Faculty of Transportation Sciences, Horská 3, 128 00 Prague, Czech Republic

Applying Spatial Statistical Methods to Predict Ground Vibration Accelerations Caused by Induced Seismicity

Piotr Bańka Łukasz Szuła
Archives of Mining Sciences | 2022 | vol. 67 | No 4 | 645-660
Keywords ground vibration attenuation relationship Joyner-Boore attenuation model spatial statistical methods
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Abstract

This paper presents the results of the research aimed at improving the accuracy of predictions regarding the maximum values of resultant components for horizontal ground vibration accelerations in areas threatened by induced seismicity. The presented solution proposes a spatial model of the ground vibration attenuation relationship based on the assumptions of the Joyner-Boore model. When performing statistical analyses to verify the models, great emphasis was placed on the correctness of applied estimation methods to meet the assumptions. The starting point for introducing spatiality into the models was the occurrence of spatial autocorrelation of the residual component when estimating the structural parameters of a model with the least-squares method. Spatial interactions were presented using weight matrices, the construction of which was based on the inverse of the distance between units. During the study, it was found that the estimated spatial model of the ground vibration attenuation relationship showed a much better match with empirical data compared to the classical Joyner-Boore attenuation model.
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Authors and Affiliations

Piotr Bańka
1
ORCID: ORCID
Łukasz Szuła
2
ORCID: ORCID
  1. The Silesian University of Technology, Faculty of Mining, Safety Engineering and Industrial Automation
  2. Polska Grupa Górnicza S.A.

Monthly changes in physicochemical parameters of the groundwater in Nida valley, Poland (case study)

Cong Ngoc Phan Andrzej Strużyński Tomasz Kowalik
Journal of Water and Land Development | 2023 | No 56 | 220-234 | DOI: 10.24425/jwld.2023.143763
Keywords groundwater Nida valley physicochemical water property statistical method water quality classification
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Abstract

The groundwater of the Nida valley was investigated to assess the quality of water source and monthly variations of the physicochemical parameters. A total of 70 water samples were collected from 7 sampling sites during a 10 months period from June 2021 to March 2022. Sampling frequency was once per month. The parameters such as temperature ( T), electrical conductivity ( EC), dissolved oxygen (DO), pH, total dissolved solids (TDS) were measured in-situ by using handheld device. Meanwhile, total nitrogen (TN), total phosphorus (TP), chloride (Cl –), sulphate (SO42–), manganese (Mn), iron (Fe), zinc (Zn), cadmium (Cd), lead (Pb), copper (Cu), chemical oxygen demand (COD) were analysed in the laboratory. According to the classification of Ministry of Marine Economy and Inland Navigation in Poland (2019), some investigated parameters are classified as unsatisfactory quality waters (class 4) and poor-quality waters (class 5) for a few specific months. Such as, TP concentrations obtained in June and January are classified as class 4, SO 4 2– concentrations corresponded to classes 4 and 5 in June, July and August, and Mn concentrations (except in January) are settled in class 5. The high values of Fe in November are arranged in class 5 and in June, July to September and March are classified in class 4. Statistical methods were used as: Shapiro–Wilk test (α = 0.05), ANOVA test and post-hoc Tukey test (α = 0.05), Kruskal–Wallis test and Wilcoxon (Mann–Whitney) rank sum test (α = 0.05) estimated the significant differences in sampling months. Pearson correlation analysis (α = 0.01 and 0.05), principal component analysis (PCA) and cluster analysis showed correlation between the parameters and sampling months.
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Authors and Affiliations

Cong Ngoc Phan
1 2
ORCID: ORCID
Andrzej Strużyński
1
ORCID: ORCID
Tomasz Kowalik
1
ORCID: ORCID
  1. University of Agriculture in Krakow, Faculty of Environmental Engineering and Land Surveying, Al. Mickiewicza 24/28, 30-059 Kraków, Poland
  2. Vinh University, Institute of Chemistry, Biology and Environment, 182 Le Duan St, Vinh City, Nghe An Province, Vietnam

Stochastic number of concrete families and the likelihood of such a value

Józef Jasiczak Marcin Kanoniczak Łukasz Smaga
Archives of Civil Engineering | 2022 | vol. 68 | No 1 | 27-44 | DOI: 10.24425/ace.2022.140154
Keywords compressive strength of concrete continuous concreting process control concrete family statistical method
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Abstract

Modern construction standards, both from the ACI, EN, ISO, as well as EC group, introduced numerous statistical procedures for the interpretation of concrete compressive strength results obtained on an ongoing basis (in the course of structure implementation), the values of which are subject to various impacts, e.g., arising from climatic conditions, manufacturing variability and component property variability, which are also described by specific random variables. Such an approach is a consequence of introducing the method of limit states in the calculations of building structures, which takes into account a set of various factors influencing structural safety. The term “concrete family” was also introduced, however, the principle of distributing the result or, even more so, the statistically significant size of results within a family was not specified. Deficiencies in the procedures were partially supplemented by the authors of the article, who published papers in the field of distributing results of strength test time series using the Pearson, ��-Student, and Mann–Whitney U tests. However, the publications of the authors define neither the size of obtained subset and their distribution nor the probability of their occurrence. This study fills this gap by showing the size of a statistically determined concrete family, with a defined distribution of the probability of its isolation.
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Authors and Affiliations

Józef Jasiczak
1
ORCID: ORCID
Marcin Kanoniczak
1
ORCID: ORCID
Łukasz Smaga
2
ORCID: ORCID
  1. Poznan University of Technology, Faculty of Civil and Transport Engineering, Piotrowo 5, 60-965 Poznan, Poland
  2. Adam Mickiewicz University, Faculty of Mathematics and Computer Science, 61-614 Poznan, Poland

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