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Słowa kluczowe pipeline dynamic seismic mining

Abstrakt

Mining tremors may have an impact on the safety risk of steel pipelines through their effects. It is therefore important to quantify the impact of a high-energy mining tremor in terms of strength. In addition, a comparison of the results obtained with the effect of a seismic tremor can illustrate the scale of such a hazard. Recently, this has been a very frequently raised issue in the area of surface protection against negative mining impacts and the protection of post-mining areas. Ensuring safe use is particularly important for gas transmission elements. This paper presents the results of a comparative analysis of the impact of mining tremors and seismic impacts on a specimen steel pipeline segment. The analyzed pipeline is located in the eastern part of Poland in the area of paraseismic impacts of the LGCD (Legnica-Glogow Copper District) mine. For this purpose, an analytical approach was used to assess the impact of seismic wave propagation on underground linear infrastructure facilities. Accelerogram records for the 02-06-2023 seismic tremor from Turkey and the mining tremor for 11-25-2020 were used. In the case of the design of underground pipelines, the cross-section of the element for which measures describing wall stress and the ovalization of the cross-section are determined is usually considered. In the situation of the influence of seismic wave propagation or so-called permanent ground deformation, the response of the pipeline in the longitudinal direction is analyzed. As a final result, longitudinal strains transferred to the pipeline as a consequence of the propagating seismic wave and mining tremor were determined. The absolute difference between the deformations in the ground and along the length of the pipeline was determined. This type of analysis has not been carried out before and provides new insights into the topic of paraseismic impacts on the scale of their interaction with natural earthquakes. Mining tremor data was obtained from the mine’s seismological department. The seismic tremor data, on the other hand, was downloaded via the publicly available ESM (Engineering Strong- Motion Database).
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Autorzy i Afiliacje

Janusz Rusek
1
ORCID: ORCID
Leszek Słowik
2
ORCID: ORCID
Krzysztof Tajduś
1
ORCID: ORCID

  1. AGH University of Krakow al. Adama Mickiewicza 30, 30-059 Krakow, Poland
  2. ITB Building Research Institute ul. Filtrowa 1, 00-611 Warsaw, Poland

Abstrakt

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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Autorzy i Afiliacje

Mariusz Giergiel

Abstrakt

New model of the simulation of the airbag inflation process, taking into account the influence of the airbag environment on the folding process, have been proposed. Equations describing a new model and the used numerical schemes were presented. The differences of the airbag fabric skin motion during the folding process, obtained by the use of different process models (existing and proposed), have been presented on the simple geometry examples. From the analysis of obtained results one acknowledged that the proposed model should be used in all calculations of the airbag operation in non-typical situations, out-of position occupants, side airbags, particularly in the case of small distances between the closed airbag and the elements of the body of the protected person.
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Autorzy i Afiliacje

Sylwester Tudruj
ORCID: ORCID
Janusz Piechna
ORCID: ORCID

Abstrakt

The paper presents the numerical model of a supply vessel-load-crane-offshore vessel system for simulation of heave motion and dynamic analysis of the system during critical phases of the handling operation: taking the load off from and lowering it to a moving base. The model enables extreme forces in elements and deflection of the structure to be determined. Different operating and emergency conditions can be simulated (e.g. horizontal motion of a supply vessel). The elaborated software can be applied also for determination of derated load charts and ultimate crane capacity (sequence of failure).
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Autorzy i Afiliacje

Marek Osiński
Andrzej Maczyński
Stanisław Wojciech

Abstrakt

The paper discusses an occurrence or latent reactions in the direction perpendicular to the movement of the suspension systems in vibratory machines supported by parallel leaf springs. These reactions occur despite an apparent lack of any forces acting in that direction and may - for long machine bodies - reach values comparable with the exciting force of the vibrator. Analytical relationships allowing for estimation of the value of reactions were derived. The obtained results were verified by means of the Geometric Element Method as well as by the performed experiments.
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Autorzy i Afiliacje

Jerzy Michalczyk
Piotr Czubak
Słowa kluczowe flight dynamics stability

Abstrakt

Dynamic stability analysis of the World Class Glider PW-5 has been presented. Glider was assumed to be a rigid body of three degrees of freedom - two linear displacements and one rotation - all in the plane of symmetry. Responses of the glider due to gust and deflection of elevator have been determined. The Laplace transform has been applied to convert the differential equations into algebraic ones. The transformed algebraic equations, after a number of manipulations have been solved for the output variables. Partial-fraction expansions have been performed to obtain the inverse Laplace transforms from the Laplace transform table. Although some restricting assumptions have been made (rigid body, small disturbances) the presented results are original and have not been presented before. The airworthiness regulations (JAR, FAR) do not require performing dynamic analysis in order the glider to be granted a Certificate of Airworthiness by the national aviation authority. To certificate the glider it is sufficient to prove static stability by means of in-flight tests. Flying qualities are qualitatively estimated basing on subjective opinions of the test pilots
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Autorzy i Afiliacje

Zdobysław Goraj
Adam Przekop

Abstrakt

It was confirmed that in the north of Poland winged specimens of Myzus persicae (Sulz.) start to migrate in spring approximately over three weeks later than in the central and sou them regions. It was observed that during the 1981-1990 and 1991-2000 decades, M. persicae started its flights approximately over two weeks earlier than during the 1971-1980 decade. With this respect one may conclude that the changes are permanent. There were also changes in quantity. In some places the M. persicae share in the entire aphid fauna on potato crops was observed to have decreased as the time passed, which, as it seems, may be associated with a decrease in potato crops area in Poland. Such a correlation can also be confirmed by the fact that in the area where M. persicae share increased, the potato crops area also increased extensively.
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Autorzy i Afiliacje

Michał Kostiw
Barbara Robak

Abstrakt

The main aim of this analysis is to consider a mutual interference between aircraft motion and surrounding flow field. Euler flow model for inviscid, compressible gas and aircraft flight dynamics model was used to analyse quick dynamic manoeuvres. For such manoeuvres, aerodynamic hysteresis has a great influence on aircraft dynamics, which cannot be simulated with the assumption of quasi-steady aerodynamics. On the other hand, the aircraft motion as a rigid body strongly influences the flow field around itself. To account for this mutual interference, the Euler flow equations were used to obtain aerodynamic forces and moments acting on a simplified aircraft configuration (main wing+ tailplane only) during pull-out manoeuvre, and the flight dynamics equations of motion were used to describe dynamics of an aircraft. Initial conditions for the flight dynamics equation of motion were settled up coming from the solution of the Euler flow model. As a test case, a weak pull-out manoeuvre was selected. During this manoeuvre, the highest value of angle of attack doesn't exceed 12 degrees - the value which can be obtained from the classical approach based on flight dynamics equations of motion with quasisteady aerodynamics. However, coupled Euler flight dynamic model has much wider applicability, and can be used for the analysis of manoeuvres at high angles of attack, including large scale separation at sharp edges, unsteadiness and flow asymmetries even for symmetrical undisturbed flowficld case. This method, if successfully verified to a number of important flight manoeuvres (such as spin, Cobra manoeuvre, roll at high angles of attack and other) can open a new, very promising field in the analysis of aircraft dynamics.
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Autorzy i Afiliacje

Tomasz Iglewski
Zdobysław Goraj
Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

In order for the ultimate state methods to be applied in dimensioning of the load-bearing elements in a conveyance, it is required that their design loads during their normal duty cycle and under the emergency braking conditions should be first established. Recently, efforts have been made to determine the interaction forces between the shaft steelwork and the conveyance under the normal operating condition [1,2]. Thus far, this aspect has been mostly neglected in design engineering. Measurement results summarised in this paper and confronted with the theoretical data [3] indicate that the major determinant of fatigue endurance of conveyances is the force acting horizontally and associated with the conveyance being hoisted in relation to the vertical force due to the weight of the conveyance and payload.
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Bibliografia

[1] F . Matachowski, PhD thesis, Opracowanie kryteriów projektowania wybranych elementów nośnych naczynia wydobywczego. AGH University of Science and Technology, Kraków, Poland (2011).
[2] S. Wolny, F. Matachowski, Operating Loads of the Shaft Steelwork – Conveyance System dne to Ranchon Irregularities of the Guiding Strings. Arch. Min. Sci. 55 (3), 589-603 (2010).
[3] S. Wolny, Wybrane problemy wytrzymałościowe w eksploatacji górniczych urządzeń wyciągowych. Monografia. Problemy Inżynierii Mechanicznej i Robotyki, AGH, Nr 20, Kraków (2003).
[4] M. Płachno, Metoda dynamiczna badań stanu zmienności naprężeń w cięgnach naczyń wyciągowych powodowanego nierównościami torów prowadzenia. In monograph: Transport szybowy 2007, Wydawnictwo KO MAG, Gliwice, II , 51-60 (2007).
[5] M. Płachno, Mathematical model of transverse vibrations of a high-capacity mining skip due misalignment of the guiding tracks in the hoisting shaft. Arch. Min. Sci. 63 (1), 3-26 (2018).
[6] D . Fuchs, H. Noeller, Untersuchungen an Haupttraggliedern hochbeanspruchter Fördermittel. Sonderabdruck aus Glückauf 124 (9), 512-514 (1998).
[7] M. Płachno, Z. Rosner, Możliwości wczesnego wykrywania procesów zmęczeniowych w cięgnach naczyń wyciągów górniczych. Bezpieczeństwo Pracy i Ochrona Środowiska w Górnictwie, Wydanie Specjalne, 241-246 (1997).
[8] S. Wolny, Interactions in mechanical systems due to random inputs on the example of a mine hoist. International Education & Research Journal, Engineering 1 (5), 70-74 (2015).
[9] S. Wolny, Displacements in mechanical systems due to random inputs in a mine hoist installation. Engineering Transactions 65 (3), 513-522 (2017).
[10] S. Wolny et al., Research work, Opracowanie kryteriów oceny konstrukcji nośnej naczyń górniczych wyciągów szybowych w aspekcie przedłużenia okresu bezpiecznej eksploatacji. Katedra Wytrzymałości Materiałów i Konstrukcji, AGH University of Science and Technology, Kraków (2003) (unpublished).
[11] A . Pieniążek, J. Weiss, A. Winiarz, Procesy stochastyczne w problemach i zadaniach. Wydawnictwo Politechniki Krakowskiej, Kraków (1999).
[12] V.A. Sretlickij, Slucajnye kolebanija mechaniceskich system. Moskva: Masinostroenie (1976).
[13] S. Wolny, Loads experienced by load-bearing components of mine hoist installations due to random irregularities and misalignments of the guide strings. Journal of Machine Construction and Maintenance 3 (110), 79-86 (2018).
[14] S. Wolny, S. Badura, Wytrzymałość cięgien nośnych górniczego naczynia wydobywczego. Journal of Civil Engineering, Environment and Architecture 34 (64), 149-158 (2017).
[15] S. Kawulok, Oddziaływanie zbrojenia szybu na mechanikę prowadzenia naczynia wyciągowego. Prace GIG, Katowice (1989).
[16] Przepisy górnicze „Rozporządzenie Rady Ministrów z dnia 30 kwietnia 2004 r. w sprawie dopuszczenia do stosowania w zakładach górniczych (Dz.U. Nr 99, poz. 1003 z 2005 r. Nr 80, poz. 695 oraz z 2007 r. Nr 249, poz. 1853, pkt 1.2 Naczynia wyciągowe” (2004).
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Autorzy i Afiliacje

Stanisław Wolny
1
ORCID: ORCID

  1. AGH University of Science and Technology, Al. A. Mickiewicza 30, 30-059 Krakow, Poland
Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

The study addresses two groups of issues occurring in modeling and experimental studies of multicomponent nonisobaric diffusion in macroporous materials. The dynamics of such processes is described in terms of systems of nonlinear partial differential equations. A method of orthogonal collocation for resolving the equations is proposed and compared with the method of lines. The second group of problems presented involves numerical simulations of diffusion in aWicke–Kallenbach diffusion cell. Such an apparatus is used in experimental studies. Particular attention is paid to diffusion in a cell closed from both sides. This is an analogue of the Duncan–Toor experiment. The effect of the number of diffusing components and their initial concentrations on the dynamics of diffusion in binary and ternary solution was studied. Hitherto unknown dynamic properties of such processes were detected and discussed.
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Bibliografia

Arnold K.R., Toor H.L., 1967. Unsteady diffusion in ternary gas mixtures. AIChE J., 13, 909–914. DOI: 10.1002/aic.690130518.
Arnošt D., Schneider P., 1995. Dynamic transport of multicomponent mixtures of gases in porous solids. Chem. Eng. J., 57, 91–99. DOI: 10.1016/0923-0467(94)02900-8.
Boron D., 2020. Izobaryczna metoda stacjonarna wyznaczania współczynników dyfuzji w materiałach porowatych. Przem. Chem., 99, 785–788. DOI: 10.15199/62.2020.5.21.
Boron D., Tabis B., 2020. Udział i znaczenie przepływu lepkiego w nieizobarycznej dyfuzji gazów przez materiały porowate. Przem. Chem., 99, 1717–1716. DOI: 10.15199/62.2020.12.4.
Duncan J.B., Toor H.L., 1962. An experimental study of three component gas diffusion. AIChE J., 8, 38–41. DOI: 10.1002/aic.690080112.
Finlayson B.A., 1972. The method of weighted residuals and variational principles. Academic Press, New York. DOI: 10.1137/1.9781611973242.
Gear C.W., 1971. Numerical initial value problems in ordinary differential equations. Prentice-Hall, Englewood Cliffs, New Jersey.
Ho C.K., Webb S.W. (Eds.), 2006. Gas transport in porous media. Springer, Netherlands. DOI: 10.1007/1-4020-3962-X.
Krishna R., Wesseling J.A., 1997. The Maxwell–Stefan approach to mass transfer. Chem. Eng. Sci., 52, 861–911. DOI: 10.1016/S0009-2509(96)00458-7.
Mason E.A., Malinauskas A.P., 1983. Gas transport in porous media: The dusty gas model. Elsevier, Amsterdam.
Remick R.R., Geankoplis C.J., 1970. Numerical study of three-component gaseous diffusion equations in transition region between Knudsen and molecular diffusion. Ind. Eng. Chem. Fundam., 9, 206–210. DOI: 10.1021/i160034a003.
Remick R.R., Geankoplis C.J., 1974. Ternary diffusion of gases in capillaries in the transition region between Knudsen and molecular diffusion. Chem. Eng. Sci., 29, 1447–1455. DOI: 10.1016/0009-2509(74)80169-7.
Schiesser W.E., 1991. Numerical methods of lines integration of partial differential equations. Academic Press, San Diego.
Tabis B., Bizon K. 2020. Opracowanie metody linii do całkowania dynamiki dyfuzji wieloskładnikowej w materiałach makroporowatych. Prace Katedry Inzynierii Chemicznej i Procesowej Politechniki Krakowskiej.
Tabis B., Bizon K., 2018. Dyfuzyjny ruch masy. Dyfuzja w gazach doskonałych i płynach rzeczywistych. Wydawnictwa Politechniki Krakowskiej, Kraków.
Tabis B., Boron D., 2020. Application of the dusty gas model for determining structural parameters of porous media. Przem. Chem., 99, 888–891. DOI: 10.15199/62.2020.6.11.
Tuchlenski A., Uchytil P., Seidel-Morgenstern A., 1998. An experimental study of combined gas phase and surface diffusion in porous glass. J. Membr. Sci., 140, 165–184. DOI: 10.1016/S0376-7388(97)00270-6.
Veldsink J.W., Versteeg G.F., van SwaaijW.M.P., 1994. An experimental study of diffusion and convection of multicomponent gases through catalytic and non-catalytic membranes. J. Membr. Sci., 92, 275–291. DOI: 10.1016/0376-7388(94)00087-5.
Yang J., Cermáková J., Uchytil P., Hamel C., Seidel-Morgenstern A., 2005. Gas phase transport, adsorption and surface diffusion in a porous glass membrane. Catal. Today, 104, 344–351. DOI: 10.1016/j.cattod.2005.03.069.
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Autorzy i Afiliacje

Katarzyna Bizon
1
ORCID: ORCID
Bolesław Tabiś
1

  1. Cracow University of Technology, Faculty of Chemical Engineering and Technology, ul. Warszawska 24, 31-155 Kraków, Poland

Abstrakt

In this paper, quanizted multisine inputs for a maneuver with simultaneous elevator, aileron and rudder deflections are presented. The inputs were designed for 9 quantization levels. A nonlinear aircraft model was exited with the designed inputs and its stability and control derivatives were identified. Time domain output error method with maximum likelihood principle and a linear aircraft model were used to perform parameter estimation. Visual match and relative standard deviations of the estimates were used to validate the results for each quantization level for clean signals and signals with measurement noise present in the data. The noise was included into both output and input signals. It was shown that it is possible to obtain accurate results when simultaneous flight controls deflections are quantized and noise is present in the data.

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Autorzy i Afiliacje

P. Lichota

Abstrakt

The advance of technical state criteria for elements of mining hoists demands a basic strength-fatigue analysis where the real values of loads and the real time function of the load variability could be used. That problem concerns also the suspension gear of skip and balance ropes, where fatigue durability should be considered as time function related to the hoist facility type. Such objective can not be achieved without comprehensive study of the dynamics of processes both in the regular operation of the facility and in its emergency states. In this work the author presents some considerations, that are however, limited to the analysis of dynamic phenomena observed in the condition of the emergency braking of the hoist facility. The results were verified by load measurements taken for some elements of the analysed real object system.
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Autorzy i Afiliacje

Stanisław Wolny
ORCID: ORCID

Abstrakt

The problem of reconstructing an unknown disturbance under measuring a part of phase coordinates of a system of linear differential equations is considered. Solving algorithm is designed. The algorithm is based on the combination of ideas from the theory of dynamical inversion and the theory of guaranteed control. The algorithm consists of two blocks: the block of dynamical reconstruction of unmeasured coordinates and the block of dynamical reconstruction of an input.

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Autorzy i Afiliacje

Marina Blizorukova
Vycheslav Maksimov

Abstrakt

We consider in this work a class of finite dimensional time-varying linear disturbed systems. The main objective of this work is to studied the optimal control which ensures the remediability of a disturbance of time-varying disturbed systems. The remediability concept consist to find a convenient control which bringing back the corresponding observation of disturbed system to the normal one at the final time. We give firstly some characterisations of compensation and in second party we find a control which annul the output of the system and we show also that the Hilbert Uniqueness Method can be used to solve the optimal control which ensure the remediability.Ageneral approachwas given to minimize the linear quadratic problem. Examples and numerical simulations are given.
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Autorzy i Afiliacje

El Mostafa Magri
1
Chadi Amissi
1
Larbi Afifi
1
Mustapha Lhous
1

  1. Fundamental and Applied Mathematics Laboratory, Department of Mathematics and Computer Science, Faculty of Sciences Ain Chock, Hassan II University of Casablanca, B.P.5366-Maârif, Casablanca, Morocco

Abstrakt

Celem prowadzonych badań było określenie zagrożenia dla gleb, wód podziemnych i roślin, jakie może powodować nawożenie osadami z mechaniczno-biologicznej oczyszczalni ścieków o wydajności nominalnej 46 000 m3/d. Próby gleb pobrano z gospodarstwa rolno-warzywnego. Doświadczenie związane z ługowaniem zanieczyszczeń prowadzono w lizymetrach z PCV (z odpływem wód przesiąkowych). Analizowane osady spełniają zarówno w zakresie chemizmu, jak i biologii wymogi stawiane osadom przeznaczonym do rolniczego wykorzystania. Odcieki z lizymetrów po 8, 16 i 24 tygodniach symulowanego ługowania opadami atmosferycznymi charakteryzują się w czasie badań zmiennym pH (tendencja wzrostowa), przewodnością elektrolityczną (tendencja spadkowa) oraz obniżającą się nieznacznie zawartością metali ciężkich. Przeprowadzone frakcjonowanie metali ciężkich w osadach ściekowych metodą sekwencyjnej ekstrakcji chemicznej wykazało, że występują one głównie w postaci związków trudno uwalniających się do roztworu glebowego (frakcje III, IV, V). Analiza sekwencyjnej ekstrakcji chemicznej przeprowadzona w glebie z zaaplikowanym osadem ściekowym po 24 tygodniach stosowania symulowanych dawek opadów wykazała podobną tendencję występowania metali ciężkich jak w samych osadach, przy czym sumaryczna zawartość ich we frakcjach I-III wynosiła od 18,6% dla Cr do 44,8% dla Zn. Pozostała ilość metali związana była głównie z frakcją V, całkowicie niedostępną dla roślin.
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Autorzy i Afiliacje

Czesława Rosik-Dulewska
ORCID: ORCID
Mirosław Mikszta

Abstrakt

By duplicating the binaural pressures of an actual source, transaural reproduction with two frontal loudspeakers is expected to recreate a virtual source in arbitrary direction. However, experiments indicated that in static transaural reproduction, the perceived virtual source is usually limited to the frontalhorizontal plane. The reasons for this limitation, as guessed, are that, in static reproduction, the dynamic cues for front-back and vertical localisation are incorrect, and the high-frequency spectral cues are unstable with head movement. To validate this hypothesis, the variations of ITD (interaural time difference) caused by head turning in both static and dynamic transaural reproductions are analysed. The results indicate that dynamic reproduction is able to create appropriate low-frequency ITD variations, and the static transaural reproduction is unable to do so. Psychoacoustic experiments are conducted to compare virtual source localisation in static and dynamic reproductions. The results indicate that dynamic reproduction is able to recreate the front, back, and vertical virtual source for low-pass stimuli below 3 kHz, while for full audible bandwidth stimulus, appropriate low-frequency dynamic cue and unstable high-frequency spectral cues in dynamic reproduction result in two splitting virtual sources.
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Autorzy i Afiliacje

Lulu Liu
1
Bosun Xie
1

  1. Acoustic Lab, School of Physics and Optoelectronics, South China University of Technology, Guangzhou, 510641, China

Abstrakt

The Baltic is a unique brakish sea. Its moderate salinity is the result of the fresh river water input and non-periodic inflows of salty, oxygenated waters from the North Sea. However, the balance continually fluctuates. What impact does that have on the sea?

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Autorzy i Afiliacje

Daniel Rak

Abstrakt

A microgrid is an appropriate concept for urban areas with high penetration of renewable power generation, which improves the reliability and efficiency of the distribution network at the consumer premises to meet various loads such as domestic, industrial, and agricultural types. Microgrids comprising inverter-based and synchronous generator-based distribution generators can lead to the instability of the system during the islanded mode of operation. This paper presents a study on designing stable microgrids to facilitate higher penetration of solar power generation into a distribution network. Ageneralized small signal model is derived for a microgrid with static loads, dynamic loads, energy storages, solar photovoltaic (PV) systems, and diesel generators, incorporating the features of dynamic systems. The model is validated by comparing the transient curves given by the model and a transient simulator subjected to step changes. The result shows that full dynamic models of complex systems of microgrids can be built accurately, and the proposed microgrid is stable for all the considered loading situations and solar PV penetration levels according to the small signal stability analysis.
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Autorzy i Afiliacje

W.E.P. Sampath Ediriweera
1
N.W.A. Lidula
1
H. Dayan B.P. Herath
2

  1. Department of Electrical Engineering, University of Moratuwa, Moratuwa, Sri Lanka
  2. Colombo City, Ceylon Electricity Board, Sri Lanka

Abstrakt

This work describes a 4-bit Flash ADC with low power consumption. The performance metrics of a Flash ADC depend on the kind of comparator and encoder used. Hence openloop comparator and mux-based encoder are used to obtain improved performance. Simulation results show that the simulated design consumes 0.265mW of power in 90nm CMOS technology using cadence-virtuoso software. The circuit operates with an operating frequency of 100MHz and a supply voltage of 1V.
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Autorzy i Afiliacje

D. S. Shylu Sam
1
P. Sam Paul
1
Diana Jeba Jingle
2
P. Mano Paul
3
Judith Samuel
1
J. Reshma
1
P. Sarah Sudeepa
1
G. Evangeline
1

  1. Karunya Institute of Technology & Sciences, Coimbatore, India
  2. Christ (Deemed to be University), Bangalore, India
  3. Alliance University, Bangalore, India

Abstrakt

The progressive development of miniature systems increases the demand for miniature parts. Reducing the size of manufactured components on one hand is a serious challenge for traditional technologies, but on the other hand, mainly by removing the energy barrier opens the possibility of using other unconventional techniques. A good example is the ultrasonic excitation of the punch during the micro-upsetting process. The anti-barreling phenomenon and dependent on the amplitude of vibrations, intensive deformation of the surface layers in contact with the tools at both ends of the sample was noted. Based on the measured strains and stresses, an increase in temperature in the extreme layers to approx. 200°C was suggested. By adopting a simplified dynamic model of the test stand, the possibility of detaching the surface of the punch from the surface of the sample was demonstrated.

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Autorzy i Afiliacje

W. Presz
Pobierz PDF Pobierz RIS Pobierz Bibtex

Abstrakt

In this paper, we present an experimental setup developed for the calibration of dynamic force transducers which is based on the drop mass method. The traceability to SI units is realized through well-known mass characteristics and a reference shock accelerometer attached to that mass. Two approaches are proposed to analyse dynamic force employing a drop mass system. One approach depends on the inertial force of a falling mass while the other deals with the work-energy principle. Results of both approaches are then compared to the response of a statically calibrated force transducer. It is shown that the obtained maximum relative deviations between the response of force transducer and the first approach results are 1% while those of the second approach are 2%.
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Bibliografia

[1] Fujii, Y., Isobe, D., Saito, S., Fujimoto, H., & Miki, Y. (2000). A method for determining the impact force in crash testing. Mechanical Systems and Signal Processing, 14(6), 959–965. https://doi.org/10.1006/mssp.1999.1272
[2] Fujii, Y. (2003). A method for calibrating force transducers against oscillation force. Measurement Science and Technology, 14(8), 1259–1264. https://doi.org/10.1088/0957-0233/14/8/310
[3] Hjelmgren, J. (2002). Dynamic Measurement of Force – A Literature Survey (SP Report 2002:34). SP Swedish National Testing and Research Institute SP Measurement Technology.
[4] Jun, Y., Yiqing, C., Xuan, H., & Xiao, Y. (2017). Impulse force calibration with dropped weight and laser vibrometer. IMEKO 23rd TC3, 13th TC5 and 4th TC22 International Conference, Finland, 19. https://www.imeko.org/publications/tc3-2017/IMEKO-TC3-2017-030.pdf
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[6] Satria, E., Takita, A., Nasbey, H., Prayogi, I. A., Hendro, H., Djamal, M., & Fujii, Y. (2018). New technique for dynamic calibration of a force transducer using a drop ball tester. Measurement Science and Technology, 29(12). https://doi.org/10.1088/1361-6501/aaeb71
[7] Schlegel, C., Kieckenap, G., Glöckner, B., Buß, A., & Kumme, R. (2012). Traceable periodic force calibration. Metrologia, 49(3), 224–235. https://doi.org/10.1088/0026-1394/49/3/224
[8] Sivaselvan, M. V., Reinhorn, A. M., Shao, X., & Weinreber, S. (2008). Dynamic force control with hydraulic actuators using added compliance and displacement compensation. Earthquake Engineering and Structural Dynamics, 37(15), 1785–1800. https://doi.org/10.1002/eqe.837
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[10] Vlajic, N., & Chijioke, A. (2017). Traceable calibration and demonstration of a portable dynamic force transfer standard. Metrologia, 54(4), S83–S98. https://doi.org/10.1088/1681-7575/aa75da
[11] Yang, Y., Zhao, Y., & Kang, D. (2016). Integration on acceleration signals by adjusting with envelopes. Journal of Measurements in Engineering, 4(2), 117–121. https://www.jvejournals.com/ article/16965/pdf
[12] Zhang, L., & Kumme, R. (2003). Investigation of interferometric methods for dynamic force measurement. In XVII IMEKO World Congress, Metrology in the 3rd Millennium, Croatia, 315–318.
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Autorzy i Afiliacje

Shaker A. Gelany
1
Gouda M. Mahmoud
1

  1. National Institute of Standards (NIS), Tersa St, El-Haram, PO Box 136, Code 12211, Giza, Egypt

Abstrakt

The article presents a new discretization method of a continuous-time linear model of sensor dynamics. It can be useful to reduce measuring errors related to the inertia of the sensor. For example it is important in the measurement of rapid processes as temperature changes in combustion chambers, or for shortening the time needed to establish the sensor readings in a transition state. There is assumed that sensor dynamics can be approximated by linear differential equation or transfer function. The searched coefficients of equivalent difference equation or discrete transfer function are obtained from Taylor expansion of a sensor output signal and then on the solution of the linear set of equations. The method does not require decomposition of sensor transfer function for zeros and poles and can be applied to the case of transfer function with zeros equal to zero. The method was used to compensate the dynamics of sensor measuring fast signals. The Bode characteristics of a compensator were compared with others derived using classical methods of discretization of linear models. Additionally, signals in time were presented to show the dynamic error before and after compensation.
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Autorzy i Afiliacje

Sławomir Gryś
1
Waldemar Minkina
2

  1. University of Technology, Faculty of Electrical Engineering, Poland
  2. Jan Dlugosz University in Czestochowa, Faculty of Science and Technology, Poland
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Abstrakt

The ongoing period of the pandemic makes everybody focused on the matters related to fighting this immense problem posed to the societies worldwide. The governments deal with the threat by publishing regulations which should allow to mitigate the pandemic, walking on thin ice as the decision makers do not always know how to properly respond to the threat in order to save people. Computer-based simulations of e.g. parts of the city or rural area should provide significant help, however, there are some requirements to fulfill. The simulation should be verifiable, supported by the urban research and it should be possible to run it in appropriate scale. Thus in this paper we present an interdisciplinary work of urban researchers and computer scientists, proposing a scalable, HPC-grade model of simulation, which was tested in a real scenario and may be further used to extend our knowledge about epidemic spread and the results of its counteracting methods. The paper shows the relevant state of the art, discusses the micro-scale simulation model, sketches out the elements of its implementation and provides tangible results gathered for a part of the city of Krakow, Poland.
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Autorzy i Afiliacje

Mateusz Paciorek
1
ORCID: ORCID
Damian Poklewski-Koziełł
2
ORCID: ORCID
Kinga Racoń-Leja
2
ORCID: ORCID
Aleksander Byrski
1
ORCID: ORCID
Mateusz Gyurkovich
2
ORCID: ORCID
Wojciech Turek
1
ORCID: ORCID

  1. AGH University of Science and Technology, al. Adama Mickiewicza 30, 30-059 Krakow, Poland
  2. Cracow University of Technology, ul. Warszawska 24, 31-155 Krakow, Poland

Abstrakt

Scaffolding is equipment usually used at construction sites. A scaffolding structure is lightweight and made of elements used many times. The characteristics of scaffolding make it susceptible to dynamic actions present at the structure or occurring nearby. A scaffolding structure of medium size was subjected to analysis in this paper. The structure FEM model was loaded with single force harmonic excitation with various frequencies ranging from 1 Hz to 12 Hz applied in one of many selected points on the scaffolding façade. In the first step, natural frequencies and mode shapes of the analyzed structure were calculated. Then the full dynamic analysis was carried out to obtain maximum displacements of selected control points. The relation of excitation force frequency and location to the amplitudes of generated displacement was observed. It was found that low excitation frequencies close to the natural frequencies of the structure produced vibrations ranging to large areas of the scaffolding surface. Higher excitation frequencies are usually less propagated at the scaffolding but still may produce some discomfort to the structure users in the vicinity of the excitation force location. Scaffolding is equipment usually used at construction sites. A scaffolding structure is lightweight and made of elements used many times. The characteristics of scaffolding make it susceptible to dynamic actions present at the structure or occurring nearby. A scaffolding structure of medium size was subjected to analysis in this paper. The structure FEM model was loaded with single force harmonic excitation with various frequencies ranging from 1 Hz to 12 Hz applied in one of many selected points on the scaffolding façade. In the first step, natural frequencies and mode shapes of the analyzed structure were calculated. Then the full dynamic analysis was carried out to obtain maximum displacements of selected control points. The relation of excitation force frequency and location to the amplitudes of generated displacement was observed. It was found that low excitation frequencies close to the natural frequencies of the structure produced vibrations ranging to large areas of the scaffolding surface. Higher excitation frequencies are usually less propagated at the scaffolding but still may produce some discomfort to the structure users in the vicinity of the excitation force location.
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Autorzy i Afiliacje

Jarosław Bęc
1
ORCID: ORCID
Ewa Błazik-Borowa
1
ORCID: ORCID
Jacek Szer
2
ORCID: ORCID

  1. Faculty of Civil Engineering and Architecture, Lublin University of Technology, Poland
  2. Faculty of Civil Engineering, Architecture and Environmental Engineering, Lodz University of Technology, Poland

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