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Number of results: 41
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Abstract

The objective of the present study was to develop a method for automatic identification of boundaries of maximal complexes on the basis of boundary points of subcomplexes. According 10 the method proposed, regions are to be presented by means of geometric cyclic digraphs. The data on these digraphs are to be recorded in a neighbourhood matrix. The matrix notation, containing supplementary data, provides information sufficient to determine complexes according to the criteria adopted. The paper presents simple algorithms for data processing, enabling to detect data inconsistency.
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Authors and Affiliations

Elżbieta Lewandowicz
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Abstract

Ibudilast (AV-411) is a non-selective inhibitor of cyclic nucleotide phosphodiesterase (PDE). It is currently marketed for human use in Asian countries for the treatment of asthma, cerebrovascular disorders and ocular allergies. Ibudilast has also been found to have an analgesic action for neuropathic pain at doses 5-10 times higher than those used in asthma therapy. Six healthy Labrador dogs were randomly assigned to two treatment groups using an open, single-dose, two-treatment, two-phase, cross-over design (2x2 Latin-square). Dogs in group 1 (n=3) were fasted for at least 10 hours overnight before the beginning of the experiment and 4 h following dosing while dogs in group 2 (n=3) received food ad libitum. During the first phase, each dog in group 1 and 2 received a single dose of 5 mg/kg ibudilast administered orally. After 1-week washout period the groups were rotated and the experiment was repeated. The analytical method, validated for dog plasma, was shown to be linear in the range 0.10–20 μg/mL. The limit of detection (LOD) and quantification (LOQ) were 0.03 and 0.1 μg/mL, respectively. No behavioural or health alterations were observed in the animals during or after the study. Ibudilast was detectable in plasma for up to 24 h showing a wide variability between animals. Although no statistically significant differences were observed in the present study between the fed and fasted states, examination of the raw data suggests that an effect may be present. The wide degree of variation observed in area under the curve (AUC) suggests that the investigation of population pharmacokinetic modelling is warranted.
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Authors and Affiliations

B. Łebkowska-Wieruszewska
V. De Vito
C.J. Kowalski
H. Owen
A. Poapolathep
A. Lisowski
M. Giorgi
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Abstract

In this study, molten salt electrorefining was used to recover indium metal from In-Sn crude metal sourced from indium tin oxide (ITO) scrap. The electrolyte used was a mixture of eutectic LiF-KF salt and InF3 initiator, melted and operated at 700°C. Voltammetric analysis was performed to optimize InF3 content in the electrolyte, and cyclic voltammetry (CV) was used to determine the redox potentials of In metal and the electrolyte. The optimum initiator concentration was 7 wt% of InF3, at which the diffusion coefficients were saturated. The reduction potential was controlled by applying constant current densities of 5, 10, and 15 mA/cm2 using chronopotentiometry (CP) techniques. In metal from the In-Sn crude melt was deposited on the cathode surface and was collected in an alumina crucible.

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Authors and Affiliations

Hyun-Gyu Lee
Sang-Hoon Choi
Jae-Jin Sim
Jae-Hong Lim
Soong-Keun Hyun
Jong-Hyeon Lee
Kyoung-Tae Park
ORCID: ORCID
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Abstract

This study investigates Thomas’ cyclically symmetric attractor dynamics with mathematical and electronic simulations using a proportional fractional derivative to comprehend the dynamics of a given chaotic system. The three-dimensional chaotic flow was examined in detail with Riemann-Liouville derivative for different values of the fractional index to highlight the sensitivity of chaotic systems with initial conditions. Thus, the dynamics of the fractional index system were investigated with Eigenvalues, Kaplan–Yorke dimension, Lyapunov exponent, and NIST testing, and their corresponding trajectories were visualized with phase portraits, 2D density plot, and Poincaré maps. After obtaining the results, we found that the integer index dynamics are more complex than the fractional index dynamics. Furthermore, the chaotic system circuit is simulated with operational amplifiers for different fractional indices to generate analog signals of the symmetric attractor, making it an important aspect of engineering. The qualitative application of our nonlinear chaotic system is then applied to encrypt different data types such as voice, image, and video, to ensure that the developed nonlinear chaotic system can widely applied in the field of cyber security.
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Authors and Affiliations

NajeebAlam Khan
1
Muhammad Ali Qureshi
2
Saeed Akbar
1
Asmat Ara
3

  1. Department of Mathematics, University of Karachi, Karachi 75270, Pakistan
  2. Department of Physics, University of Karachi, Karachi 75270, Pakistan
  3. College of Humanities and Sciences, PAF-KIET, Karachi 75190, Pakistan
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Abstract

This study analysed the influence of montelukast (MON; 10-8 - 10-4 M), a cysteinyl leukotriene receptor 1 (CysLTR1) antagonist, on the contractility of the porcine uterine smooth muscle in the luteal phase of the oesterous cycle (n=8) and in early pregnancy (n=8). Stimulation of uterine strips in the luteal phase with MON has been shown to significantly reduce the amplitude of con- tractions, but not to affect the tension or frequency of contractions. A statistically significant tension increase and decrease in the frequency and amplitude of contractions was observed in pigs in early pregnancy. This suggests that MON has a different effect on the parameters under study in cyclic and pregnant pigs.

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Authors and Affiliations

W. Markiewicz
A. Wiśniewska
H. Madej-Śmiechowska
A. Burmańczuk
J.J. Jaroszewski
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Abstract

An useful electrochemical sensing approach was developed for norepinephrine (NE) detection based on semiconducting polymer (9-nonyl-2,7-di(selenophen-2-yl)- 9H-carbazole) and laccase modified platinum electrode (Pt). The miniature Pt biosensor was designed and constructed via the immobilization of laccase in an electroactive layer of the electrode coated with thin polymeric film. This sensing arrangement utilized the catalytic oxidation of NE to norepinephrine quinone. The detection process was based on the oxidation of catecholamine in the presence of enzyme – laccase. With the optimized conditions, the analytical performance demonstrated selectivity in a wide linear range (0.1–200x10-6 M) with a detection limit of 240 nM and a quantification limit of 365 nM. Moreover, the method was successfully applied for selective NE determination in the presence of interfering substances.

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Authors and Affiliations

Sylwia Baluta
Agnieszka Swist
Joanna Cabaj
Karol Malecha
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Abstract

Combustion technology of the coal-water suspension creates a number of new possibilities to organize the combustion process fulfilling contemporary requirements, e.g. in the environment protection. Therefore the in-depth analysis is necessary to examine the technical application of coal as a fuel in the form of suspension. The research undertakes the complex investigations of the continuous coal-water suspension as well as cyclic combustion. The cyclic nature of fuel combustion results from the movement of the loose material in the flow contour of the circulating fluidized bed (CFB): combustion chamber, cyclone and downcomer. The experimental results proved that the cyclic change of oxygen concentration around fuel, led to the vital change of both combustion mechanisms and combustion kinetics. The mathematical model of the process of fuel combustion has been presented. Its original concept is based on the allowance for cyclic changes of concentrations of oxygen around the fuel. It enables the prognosis for change of the surface and the centre temperatures as well as mass loss of the fuel during combustion in air, in the fluidized bed and during the cyclic combustion.

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Authors and Affiliations

Agnieszka Kijo-Kleczkowska
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Abstract

Paper presents the assessment of impact of heat treatment on durability in low-cycle fatigue conditions (under constant load) in castings

made using post-production scrap of MAR-247 and IN-713C superalloys. Castings were obtained using modification and filtration

methods. Additionally, casting made of MAR-247 were subjected to heat treatment consisting of solution treatment and subsequent aging.

During low-cycle fatigue test the cyclic creep process were observed. It was demonstrated that the fine-grained samples have significantly

higher durability in test conditions and , at the same time, lower values of plastic deformation to rupture Δϵpl. It has been also proven that

durability of fine-grained MAR-247 samples can be further raised by about 60% using aforementioned heat treatment.

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Authors and Affiliations

M. Cieśla
G. Junak
P. Gradoń
F. Binczyk
M. Mańka
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Abstract

Electrocatalytic gas sensors belong to the family of electrochemical solid state sensors. Their responses are acquired in the form of I-V plots as a result of application of cyclic voltammetry technique. In order to obtain information about the type of measured gas the multivariate data analysis and pattern classification techniques can be employed. However, there is a lack of information in literature about application of such techniques in case of standalone chemical sensors which are able to recognize more than one volatile compound. In this article we present the results of application of these techniques to the determination from a single electrocatalytic gas sensor of single concentrations of nitrogen dioxide, ammonia, sulfur dioxide and hydrogen sulfide. Two types of classifiers were evaluated, i.e. linear Partial Least Squares Discriminant Analysis (PLS-DA) and nonlinear Support Vector Machine (SVM). The efficiency of using PLS-DA and SVM methods are shown on both the raw voltammetric sensor responses and pre-processed responses using normalization and auto-scaling

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Authors and Affiliations

Paweł Kalinowski
Łukasz Woźniak
Anna Strzelczyk
Piotr Jasinski
Grzegorz Jasiński
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Abstract

cAMP is a second messenger which plays a regulatory role in a wide variety of biological processes in organisms ranging from prokaryotes to higher eukaryotes, but knowledge of its role in macroalgae and vascular plants is limited. We modified cAMP levels in the macroalga Chara vulgaris thallus and studied the effects on thallus growth and gametangia development: db-cAMP (permeable analog of cAMP), adenylate cyclase (AC) activator, forskolin and theophylline (cAMP phosphodiesterase (PDE) inhibitor) were used to elevate cAMP levels, and the AC inhibitors 2'-dAdo and 2'-d3'-AMP were used to decrease them. The results suggest that in Chara vulgaris the cAMP pathway may regulate both vegetative thallus growth and gametangia development, and that these effects may depend on this second-messenger level. Elevated cAMP stimulated thallus growth and delayed gametangia development; decreased cAMP inhibited thallus growth and accelerated maturation of both antheridia and oogonia. These results suggest that the cAMP pathway participates in regulation of developmental processes in Chara vulgaris and that thallus growth and gametangia development require different cAMP levels in cells.

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Authors and Affiliations

Aneta Domańska
Mirosław Godlewski
Agnieszka Kobylińska
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Abstract

The objective of this paper is to derive the characteristics of an effective governance framework ensuring incentives for conducting a prudent fiscal policy.We study this problem with the use of econometric tools and a sample of 28 European Union Member States between 2003 and 2017. By looking at specific reforms and measures, not only we verify the synthetic effectiveness of fiscal constraints but also we analyse specific elements of the governance framework.Our study shows that fiscal balances are affected not only by the economic cycle, but, among others, by the level of public debt and its cost. We find that the existence of numerical fiscal rules, in that specifically revenue and expenditures rules, their strong legal entrenchment, surveillance mechanisms, sanctions, and flexibility with respect to business cycle have a significant impact on curbing deficits.

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Authors and Affiliations

Grzegorz Poniatowski
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Abstract

In order to explore the mining failure law of deep coal seam floor and clarify the mechanical behavior and energy change in the floor strata during mining, the mechanical properties and energy evolution law of sandstone under cyclic loading with different confining pressures (20, 30, 40 MPa) were studied using the Rock Top multi-field coupling tester. The results are as follows: (1) the hysteresis phenomenon of a rock stress-strain curve under cyclic loading is evident. Moreover, the hysteresis loop migrates to the direction of strain increase, and the fatigue damage caused by cyclic loading has a certain weakening effect on the peak strength of rock; (2) both the number of cycles and the axial strain show a nonlinear change characteristic that satisfies the quadratic function relationship. Among them, the stress level of the rock is the main factor affecting the fitting effect; (3) under the same confining pressure, with an increase in cycle level, the macroscopic deformation of the rock increases, the accumulation of fatigue damage in the sample increases, and the irreversible deformation of the rock increases, which leads to an increase in energy input and dissipation; (4) in terms of elastic energy and dissipation energy, elastic energy plays a dominant role. In the initial cycle, the rock is destroyed, and the rock energy loss is great. After the second cycle, the input energy is mainly stored in the rock in the form of elastic energy, and only a small part of the input energy is released in the form of dissipation energy; (5) the confining pressure can improve the efficiency of rock absorption and energy storage, enhance the energy storage limit of rock, and limit the dissipation and release of partial energy of rock. The greater the confining pressure, the more evident the limiting effect, and the more significant the dominant position of elastic energy; and (6) the change in the energy dissipation ratio can be divided into three stages: rapid decline stage, stable development stage and rapid rise stage. The greater the increase in dissipation energy, the greater the degree of rock damage. The evolution process of the energy dissipation ratio can reflect the internal damage accumulation process of rock well, which can be used as the criterion of rock instability.
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Authors and Affiliations

Daqiang Xu
1
ORCID: ORCID
Peisen Zhang
1
ORCID: ORCID
Wei Yan
1
ORCID: ORCID
Xiaole Zhang
1
ORCID: ORCID
Yuhang Dong
1
ORCID: ORCID
Hui Niu
1
ORCID: ORCID

  1. Shandong University of Science and Technology, National Key Laboratory for Mine Disaster Prevention and Control, Qingdao, Shandong 266590, China
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Abstract

The Non Line of Sight (NLOS) broadband wireless access provided by Worldwide Interoperability for Microwave Access (WiMAX) operating in 2-11 GHz frequency is susceptible to the effects of multipath propagation, diffraction fading, vegetation attenuation, shadowing loss etc. In order to overcome these effects effective fade mitigation techniques, have to be implemented. The Orthogonal Frequency Division Multiplexing- Multiple Input Multiple Output (OFDM-MIMO) is an efficient method that helps in combatting the fading and providing higher SNR to the WiMAX system. According to the IEEE 802.16 specification, for QPSK modulation, a threshold SNR of 6 dB is required for the link to operate. In the present work the use of OFDM-MIMO achieves a SNR above this operating threshold.
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Authors and Affiliations

Sharmini Enoch
1
Ifiok Otung
2

  1. Department of Electronics and Communications,Noorul Islam University, India
  2. Faculty of Engineering and Informatics, Department of Biomedical and Electronics Engineering University of Bradford, United Kingdom
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Abstract

A n-type semiconductor ZnO has high transmittance features, excellent chemical stability and electrical properties. It is also commonly used in a range of fields, such as gas sensors, photocatalysts, optoelectronics, and solar photocell. Magnesium-doped zinc oxide (Mg-ZnO) nano powders were effectively produced using a basic chemical precipitation process at 45°C. Calcined Mg-ZnO nano powders have been characterized by FTIR, XRD, SEM-EDX and PL studies. XRD measurements from Mg-ZnO revealed development of a crystalline structure with an average particle size of 85 nm and SEM analysis confirmed the spherical morphology. Electrochemical property of produced Mg-ZnO nanoparticles was analyzed and the specific capacitance value of 729 F g–1 at 0.5 A g–1 current density was recorded and retained a specific capacitance ~100 percent at 2 A g–1 current density.
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Authors and Affiliations

S. Arul
1
ORCID: ORCID
T. Senthilnathan
2
ORCID: ORCID
V. Jeevanantham
3
ORCID: ORCID
K.V. Satheesh Kumar
4
ORCID: ORCID

  1. Jai Shriram Engineering College, Department of Physics, Tirupur-638660, Tamilnadu, India
  2. Sri Venkateshwara College of Engineering, Department of Applied Physics, Sriperumbudur-602117, Tamilnadu, India
  3. Vivekanandha College of Arts & Sciences for Women, Department of Chemistry, Tiruchengode 637205, Tamilnadu, India
  4. Kongu Engineering College, Department of Mechanical Engineering, Erode-638060, Tamilnadu, India
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Abstract

This paper presents the results of experimental studies and numerical simulations of the ratcheting for the PA6 aluminum. In the initial determination of the material hardening parameters, the samples were subjected to the symmetrical strain-controlled cyclic tension-compression test. The experimental stress-strain curve was compared with the numerical one obtained for non-linear Frederick-Armstrong and Voce models. For better fitting of both curves, the optimization procedure based on the least-square method and the fuzzy logic was applied. After establishing the hardening parameters, numerical simulations of the ratcheting were made. The boundary value problem was solved by means of discrete analysis. The data (force and displacement) obtained in numerical computations were used to control the ratchetting experiment. The results of experiments and numerical calculations were compared. Good convergence proves the reliability of the determination of material hardening data.

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Authors and Affiliations

A. Skrzat
ORCID: ORCID
Marta Wójcik
ORCID: ORCID
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Abstract

To investigate the effect of cyclic heat treatment on the microstructure evolution of titanium alloys, TA15 alloys were subjected to different numbers of heat treatment cycles at various temperatures in the (α + β) two-phase region. The resulting microstructure and hardness of the alloy were characterized by using the metallographic microscopy, scanning electron microscopy, and Vickers hardness testing. The morphology of the initial TA15 alloy was nearly equiaxed structure. The α phase content, thickness of the oxygen-rich α layer, and hardness of the TA15 alloy increased with the number of cycles. The morphology of the TA15 alloy changed into the Widmannstatten structure when the alloy underwent six cycles of heat treatment between 970 and 800°C. The thickness of the oxygen-rich α layer and hardness of the alloy increased with the lower limit temperature of the cyclic heat treatment. Compared with the number of cycles, the lower limit temperature of the cyclic heat treatment was a more significant factor on the microstructure evolution of the TA15 titanium alloy.
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Authors and Affiliations

Dan-Ya Zhang
1
Zhi-Sheng Nong
2
Tian-Xing Wang
2

  1. Shenyang Aerospace University, Key Laboratory of Fundamental Science for National Defense of Aeronautical Digital Manufacturing Process, Shenyang110136, China
  2. Shenyang Aerospace University, School of Materials Science and Engineering, Shenyang 110136, China
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Abstract

Two single crystals with compositions Fe-Ni-Co-Al-Ta and Fe-Ni-Co-Al-Ta-B were selected and fabricated by Bridgman method. Subsequently, ingots were homogenized, oriented and subjected to a two-step heat treatment process in order to obtain fine and coherent γ' precipitates. Subsequently, superelastic cycling experiments were performed at 77 K. The next step included detailed microstructural characterization using transmission electron microscopy and high-energy synchrotron X-ray diffraction measurements together with Rietveld refinement. The results show that the number of fully reversible superelastic strains is very sensitive to the size of γ' precipitates. The smaller (3 nm) γ' precipitates ensured more superelastic response compared to material with larger γ' particles size (5 nm), in which the material did not receive its original shape after 10 cycles even after being heated.
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Authors and Affiliations

A. Wójcik
1
ORCID: ORCID
R. Chulist
1
ORCID: ORCID
A. Szewczyk
1
ORCID: ORCID
J. Dutkiewicz
1
ORCID: ORCID
Wojciech Maziarz
ORCID: ORCID

  1. Institute of Metallurgy and Materials Science, 25 Reymonta Str., 30-059 Krakow, Poland
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Abstract

At present, many studies have been carried out on the fatigue mechanical properties of conventional rocks, but there are few studies on the mechanical properties of rocks after water rock interaction. The aim is to better study the fatigue mechanical characteristics of sandstone after dry wet cycle and the research object we take was sandstone samples after a certain number of drying and wetting cycles. The WAW-2000 electro-hydraulic servo pressure system was used to carry out uniaxial fatigue cyclic loading and unloading tests with different amplitudes and different upper limit stresses. The test found that: when the sample is damaged under fatigue load, the stress-strain curve shows a sharp downward trend and a sudden instability failure occurred in the sample.With the increase of the upper limit stress and amplitude, the life of the sample decreases gradually which also conforms to the change of power function. Then the relationship between fatigue life and stress is obtained. The fatigue stress-strain curve is characterized by sparse-dense-sparse. With the increase of cycle time, the axial strain of the sample shows an inverted “S” shape. The strain change can be divided into three stages: initial stage, constant velocity stage and acceleration stage.
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Authors and Affiliations

Jin-Song Zhang
1
ORCID: ORCID
Yu Lu
1
ORCID: ORCID
Heng-Liang Zhang
2
ORCID: ORCID
Yu-Di Yang
1
ORCID: ORCID
Yi-Shun Bu
1
ORCID: ORCID

  1. Anhui University of Science and Technology, No. 168, Taifeng street, Huainan City, Anhui Province, China
  2. First Design and Research Institute MI China Co, No. 12550, bustling Avenue, Hefei Economic and Technological Development Zone, Anhui Province, China
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Abstract

The cyclicity of the state matrices of positive linear electrical circuits with the chain structure is considered. Two classes of positive linear electrical circuits with the chain structure and cyclic Metzler state matrices are analyzed. Some new properties of these classes of positive electrical circuits are established. The results are extended to fractional linear electrical circuits.
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Bibliography

  1.  A. Berman and R.J. Plemmons, Nonnegative Matrices in the Mathematical Sciences. Philadelphia: SIAM, 1994.
  2.  L. Farina and S. Rinaldi, Positive Linear Systems; Theory and Applications. New York: J. Wiley, 2000.
  3.  T. Kaczorek, Positive 1D and 2D Systems. London: Springer-Verlag, 2002.
  4.  T. Kaczorek, “Positive linear systems with different fractional orders,” Bull. Pol. Acad. Sci. Tech. Sci., vol. 58, no. 3, pp. 453–458, 2010.
  5.  T. Kaczorek, “Normal fractional positive linear systems and electrical circuits,” in Proc. Conf. Automation 2019, Warsaw, 2020, pp. 13–26.
  6.  T. Kaczorek, Selected Problems of Fractional Systems Theory. Berlin: Springer, 2011.
  7.  T. Kaczorek and K. Rogowski, Fractional Linear Systems and Electrical Circuits. Cham: Springer, 2015.
  8.  W. Mitkowski, “Dynamical properties of metzler systems,” Bull. Pol. Acad. Sci. Tech. Sci., vol. 54, no. 4, pp. 309–312, 2008.
  9.  W. Mitkowski, Outline of Control Theory. Kraków: Publishing House AGH, 2019.
  10.  P. Ostalczyk, Discrete Fractional Calculus. River Edge, NJ: World Scientific, 2016.
  11.  I. Podlubny, Fractional Differential Equations. San Diego: Academic Press, 1999.
  12.  T. Kaczorek, “Reachability and observability of positive discrete-time linear systems with integer positive and negative powers of the state frobenius matrices,” Arch. Control Sci., vol. 28, no. 1, pp. 5–20, 2018.
  13.  M.D. Ortigueira and J. A. Tenreiro Machado, “New discrete-time fractional derivatives based on the bilinear transformation: definitions and properties,” J. Adv. Res., vol. 25, pp. 1–10, 2020.
  14.  A. Ruszewski, “Stability of discrete-time fractional linear systems with delays,” Arch. Control Sci., vol. 29, no. 3, pp. 549–567, 2019.
  15.  L. Sajewski, “Stabilization of positive descriptor fractional discrete-time linear systems with two different fractional orders by decentralized controller,” Bull. Pol. Acad. Sci. Tech. Sci., vol. 65, no. 5, pp. 709–714, 2017.
  16.  R. Stanisławski, K. Latawiec, and M. Łukaniszyn, “A comparative analysis of laguerre-based approximatiors to the grunwald-letnikov fractional-order difference,” Math. Probl. Eng., vol. 2015, 2015.
  17.  F.G. Gantmacher, The Theory of Matrices. London: Chelsea Pub. Comp., 1959.
  18.  T. Kaczorek and K. Borawski, “Stability of continuoustime and discrete-time linear systems with inverse state matrices,” Meas. Autom. Monit., vol. 62, no. 4, pp. 132–135, 2016.
  19.  T. Kaczorek, Polynomial and Rational Matrices. London: Springer, 2007.
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Authors and Affiliations

Tadeusz Kaczorek
1
ORCID: ORCID

  1. Bialystok University of Technology, Faculty of Electrical Engineering, Wiejska 45D, 15-351 Białystok, Poland
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Abstract

The positivity and cyclicity of descriptor linear electrical circuits with chain structure is considered. Two classes of descriptor linear electrical circuits are analyzed. Some new properties of these classes of electrical circuits are established. The results are extended to fractional descriptor linear electrical circuits.
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Bibliography

  1.  A. Berman and R.J. Plemmons, Nonnegative Matrices in the Mathematical Sciences. Philadelphia: SIAM, 1994.
  2.  L. Farina and S. Rinaldi, Positive Linear Systems; Theory and Applications. New York: J. Wiley, 2000.
  3.  T. Kaczorek, Positive 1D and 2D Systems. London: Springer-Verlag, 2002.
  4.  T. Kaczorek, “Positive linear systems with different fractional orders,” Bull. Pol. Acad. Sci. Tech. Sci., vol. 58, no. 3, pp. 453– 458, 2010.
  5.  T. Kaczorek, Selected Problems of Fractional Systems Theory. Berlin: Springer, 2011.
  6.  T. Kaczorek, “Normal fractional positive linear systems and electrical circuits,” in Proc. Conf. Automation 2019, Warsaw, 2020, pp. 13–26.
  7.  T. Kaczorek and K. Rogowski, Fractional Linear Systems and Electrical Circuits. Cham: Springer, 2015.
  8.  W. Mitkowski, “Dynamical properties of Metzler systems,” Bull. Pol. Acad. Sci. Tech. Sci., vol. 54, no. 4, pp. 309–312, 2008.
  9.  W. Mitkowski, Outline of Control Theory. Kraków: Publishing House AGH, 2019.
  10.  P. Ostalczyk, Discrete Fractional Calculus. River Edge, NJ: World Scientific, 2016.
  11.  I. Podlubny, Fractional Differential Equations. San Diego: Academic Press, 1999.
  12.  T. Kaczorek, “Reachability and observability of positive discrete-time linear systems with integer positive and negative powers of the state frobenius matrices,” Arch. Control Sci., vol. 28, no. 1, pp. 5–20, 2018.
  13.  M.D. Ortigueira and J.A. Tenreiro Machado, “New discrete-time fractional derivatives based on the bilinear transformation: definitions and properties,” J. Adv.Res., vol. 25, pp. 1–10, 2020.
  14.  A. Ruszewski, “Stability of discrete-time fractional linear systems with delays,” Arch. Control Sci., vol. 29, no. 3, pp. 549– 567, 2019.
  15.  L. Sajewski, “Stabilization of positive descriptor fractional discrete-time linear systems with two different fractional orders by decentralized controller,” Bull. Pol. Acad. Sci. Tech. Sci., vol. 65, no. 5, pp. 709–714, 2017.
  16.  R. Stanisławski, K. Latawiec, and M. Łukaniszyn, “A Comparative Analysis of Laguerre-Based Approximatiors to the Grunwald-Letnikov Fractional-Order Difference,” Math. Probl. Eng., vol. 2015, p. 512104, 2015.
  17.  L. Dai, Singular Control Systems, ser. Lecture Notes in Control and Information Sciences. Berlin: Springer, 1989, vol. 118.
  18.  D. Guang-Ren, Analysis and Design of Descriptor Linear Systems. New York: Springer, 2010.
  19.  T. Kaczorek, Linear Control Systems. vol. 1. New York, USA: J. Wiley, 1992.
  20.  T. Kaczorek and K. Borawski, Descriptor Systems of Integer and Fractional Orders, ser. Studies in Systems, Decision and Control. Cham: Springer, 2021, vol. 367.
  21.  K. Borawski, “Superstabilization of Descriptor ContinuousTime Linear Systems via State-Feedback Using Drazin Inverse Matrix Method,” Symmetry, vol. 12, no. 6, p. 940, 2020.
  22.  M. Rami and D. Napp, “Characterization and Stability of Autonomous Positive Descriptor Systems,” IEEE Trans. Autom. Contr., vol. 57, no. 10, pp. 2668–2673, 2012.
  23.  E. Virnik, “Stability analysis of positive descriptor systems,” Linear Algebra Appl., vol. 429, no. 10, pp. 2640–2659, 2008.
  24.  F.G. Gantmacher, The Theory of Matrices. London: Chelsea Pub. Comp., 1959.
  25.  T. Kaczorek, “Positive electrical circuits with the chain structure and cyclic Metzler state matrices,” Bull. Pol. Acad. Sci. Tech. Sci., vol. 69, no. 4, pp. 1–5, 2021.
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Authors and Affiliations

Tadeusz Kaczorek
1
ORCID: ORCID
Kamil Borawski
1

  1. Bialystok University of Technology, Faculty of Electrical Engineering, ul. Wiejska 45D, 15-351 Białystok, Poland
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Abstract

The article is an attempted analysis of the literary genre of fable as a case study of a selection of fables by Lyudmila Petrushevskaya. In particular, the analysis focuses on the fable cycles: The New Adventures of Helen the Beautiful, Adventures of Barbie and Wild Animal Fables. The perspective adopted in the article focuses mainly on the axiological aspect of the fables and the reconstruction of their moral message. The moral sense in Petrushevskaya’s fables is veiled under their overt sense. Even the overt sense is hidden deeply under the multiple levels of “intertextual irony” (Eco). The analysis also explores the links between Petrushevskaya’s works, folk magical fairy tales and the prototypical genre of the classical Russian fable. The innovative fables created by Petrushevskaya de-conventionalize the classical schemata of the genre, and as such they constitute an ironic, mocking and sometimes a bitter commentary on the contemporary world. The fables exhibit a high degree of “poetics of everyday life” – a merger of popular and high culture. They both recreate and at the same time mock the schemata and rituals of pop culture, also displaying noticeable feminist tones. In their poetics, the fables employ cyclic and serial arrangement, and are completed with “words of wisdom” that are far from naïve moral judgements.

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Authors and Affiliations

Anna Woźniak
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Abstract

In this study, the compressive deformation of crushed sandstone was tested using a crushed rock deformation-seepage test system, and the effects of various factors, including crushed rock grade, grade combination, water saturation status, and stress loading method (i.e., continuous loading or cyclic loading and unloading), on the compressive deformation of crushed sandstone was analyzed from four perspectives including stress-strain, bulking coefficient, deformation mechanism and energy dissipation. The results indicate that the stress-strain relations of crushed sandstone are closely associated with all factors considered, and are well represented by exponential functions. The strain observed for a given applied stress increased with increasing crushed rock grade throughout the loading period. Crushed sandstone grades were combined according to a grading index (n), where the proportion of large-grade rocks in the sample increased with increasing n. The bearing capacity of a water-saturated crushed sandstone sample with n = 0.2 was less than that of an equivalent dry sample for a given applied stress. The stress-strain curve of a water-saturated crushed sandstone sample with n = 0.2 under cyclic loading and unloading was similar to that obtained under continuous loading. Observation and discovery, the deformation mechanism of crushed sandstone was mainly divided into four stages, including crushing, rupture, corner detachment and corner wear. And 20% of the work done by testing machine is used for friction between the crushed sandstone with the inner wall of the test chamber, and 80% is used for the closing of the void between the crushed sandstone, friction sliding, crushing damage.

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Authors and Affiliations

Yanan Sun
Peisen Zhang
ORCID: ORCID
Wei Yan
ORCID: ORCID
Fenqian Yan
Junda Wu

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