Wyniki wyszukiwania - BazTech

1

Energy efficiency optimization of milk homogenizers: a contribution to the european green deal goals

Samoichuk Kyrylo, Kovalyov Alexandr, Palianychka Nadiia, Hutsol Taras, Komarnitskyi Serhii, Bezaltychna Olena, Kuboń Maciej, Tabor Sylwester, Kukharets Valentyna

Production Engineering Archives

|

2025

|

Vol. 31, Iss. 1

15--26

EN

The modern global milk processing industry involves the use of innovations and optimization of existing industry management methods, which contributes to the realization of sustainable development and energy efficiency. Increasing the energy efficiency of dispersing and homogenizing milk and dairy products can contribute to the practical implementation of the philosophy of the "European Green Deal". The jet-slot milk homogenizer is one of the most energy-efficient among all types of homogenizers in the dairy industry. The principle of its operation is based on the creation of a maximum speed difference between the fat balls of cream and the flow of skimmed milk. This makes it possible to obtain a high degree of dispersion with high energy efficiency of the process. Reducing the specific energy consumption and finding the optimal parameters of the homogenizer were based on the results of both theoretical and experimental studies and were carried out graphically. The optimization criteria (decreasing specific energy consumption while maintaining high homogenization quality) were chosen to achieve a dispersion of 0.8 μm with minimal energy consumption. The diameter of the confusor is optimized at the point of greatest narrowing. The obtained results indicate that to increase the energy efficiency of homogenization, the parameter values should be within 3.5–4.0 mm. The parameters of the width of the ring gap, the fat content and the speed of the cream are optimized. The results showed that it is possible to reduce the specific energy intensity of the process to values of 0.88–0.92 kWh/t when using cream with a fat content of 33–43%, which should be fed through an annular gap with a width of 0.6–0.8 mm. Optimum values of the cream feed speed were found, which should be equal to 7–11 m/s. The research results are of high practical value for the further development of an energy-efficient industrial model of a jet-slot homogenizer.

2

Degree of Dust Dispersion in the Atmosphere under the Influence of Microclimatic, Topographical and Technical Factors

Ciepiela Maciej, Sobczyk Wiktoria, Sobczyk Eugeniusz Jacek

Inżynieria Mineralna

|

2025

|

Vol. 1, no. 1

117--122

EN

The process of dispersion of a component in a given medium such as air is determined by three groups of factors: microclimatic, topographical and technical. The shape of the emitted pollutant plume depends on the parameters of the emitter and the volume of the air masses. This article describes five types of plume: looping, conical, ventilating, tracing and contaminating. Vertical air stability is an important physical parameter of the atmosphere. Three states of this parameter are described in this paper: inversion, convection and isotherm. The degree of pollutant dispersion is influenced by air temperature, shaping physical and chemical processes that include coagulation, sorption and diffusion. Topographical factors include landform type, land cover and development. A significant number of obstacles interfere with the free flow of air through a given area. Technical factors relate to the emitter parameters (altitude, diameter) and the nature of its operation (time, temperature, speed of pollutants at discharge). Emissions can come from a large pointsource emitter or from multiple diffuse emitters. Meteorological factors were found to have a decisive influence, as climatic parameters are subject to the greatest changes due to atmospheric turbulence, vertical temperature gradient, wind effect and precipitation.

PL

Proces rozpraszania składnika w danym ośrodku, jakim jest powietrze, jest uwarunkowany trzema grupami czynników: mikroklimatycznymi, topograficznymi oraz technicznymi. Kształt wyemitowanej smugi zanieczyszczeń zależy od parametrów emitora oraz od objętości mas powietrza. W artykule opisano pięć typów smug: pętlowy, stożkowy, wentylacyjny, trasujący i zanieczyszczający. Pionowa stateczność powietrza jest ważnym parametrem fizycznym atmosfery. W pracy zostały opisane trzy stany tego parametru: inwersja, konwekcja i izotermia. Na stopień dyspersji zanieczyszczeń wpływa temperatura powietrza, kształtująca procesy fizyczne oraz chemiczne, do których należą koagulacja, sorpcja oraz dyfuzja. Do czynników topograficznych zalicza się typ ukształtowania terenu, jego pokrycie oraz zagospodarowanie. Duża liczba przeszkód zaburza swobodny przepływ powietrza przez dany obszar. Czynniki techniczne dotyczą parametrów emitora (wysokość, średnica) oraz charakteru jego pracy (czas, temperatura, prędkość zanieczyszczeń na wylocie). Emisja może pochodzić z dużego emitora punktowego lub z wielu rozproszonych emitorów. Stwierdzono, że decydujący wpływ mają czynniki meteorologiczne, gdyż parametry klimatyczne podlegają największym zmianom w wyniku turbulencji atmosfery, pionowego gradientu temperatury, działania wiatru i opadu atmosferycznego.

3

The waveform comparison of three fractional viscous acoustic wave equations

Wang Dan, Wang Zhiliang, Zhang Xinmin, Huang Rong, Song Ziang, Song Guojie

Acta Geophysica

|

2025

|

Vol. 73, no. 1

311--320

EN

The forward simulation of the viscous acoustic wave equation is essential for understanding wave propagation and seismic inversion. The viscous acoustic seismic wave equations are diverse, even if we limit the study scope to the fractional viscous wave equations. In present study, we consider three Riesz fractional viscous wave equations: the Fractional Viscous Acoustic Wave (FVAW) equation, Dispersion-Dominated Wave (DDW) equation, and Attenuation-Dominated Wave (ADW) equation. The Acoustic Wave (AW) equation, as a special fractional wave equation, is used to compare with the three fractional viscous acoustic equations. The Asymptotic Local Finite Difference (ALFD) method is adopted to solve the fractional derivative term; while, the Lax-Wendroff Correction (LWC) scheme is used to solve the integer derivative term. The analysis results indicate that the numerical scheme of the ADW equation exhibits the most rigorous stability condition, and that of the DDW equation is the most flexible. When the product of complex wavenumber k and spatial step size h equal to π, the maximum phase velocity errors of the FVAW equation, DDW equation, ADW equation, and AW equation are 27.78%, 28.02%, 2.25%, and 3.04%, respectively. Numerical experiments demonstrate that the FVAW equation not only governs the arrival time but also influences the amplitude. The DDW equation governs the arrival time but not amplitude; while, the ADW equation controls the amplitude but not arrival time. As the quality factor Q decreases, the viscous features of these three wave equations become pronounced. The change of amplitude is more noticeable than that of arrival time, suggesting that arrival time is more robust than amplitude. Based on these findings, we suggest incorporating the step for selecting the governing equations when dealing with practical Full-Waveform Inversion, which is helpful to improve the accuracy and reliability of the inversion results. Our results not only emphasize the importance of understanding the behavior of viscous wave equations, but also provide waveform evidence for selecting seismic governing equations in Full-Waveform Inversion.

4

Algorithm for detection of wave packets in a circular waveguide

Wrzeciono Piotr, Szymański Michał, Bayat Hydayatullah

Vibrations in Physical Systems

|

2024

|

Vol. 35, nr 1

art. no. 2024111

EN

This paper presents an algorithm for detecting wave packets in a circular waveguide. The waveguide terminated with a concrete plug was used to test the method. The concrete was made in accordance with the Eurocode standard. During the tests, a significant difference was observed between the behavior of the speaker and the concrete plug. The pulse reflected from the plug maintained its shape regardless of the sound level. The reflection of the pulse from the speaker's diaphragm resulted in a significant change in the form and duration of the wave packet. These changes were dependent on the sound level of the wave packet. As a result of these modifications was a significant difference between the measurement uncertainty of detecting a pulse reflected from the concrete and the speaker. In the case of reflection from the speaker, an uncertainty of 0.036% was obtained. The smallest measurement error value for the pulse reflected from the speaker was 2.5%.

5

Structure and properties of self-extinguishing rigid polyurethane foam with inorganic filler

Szymiczek Małgorzata, Sarraj Sara, Chomiak Monika, Chmielnicki Błażej, Gajlewicz Izabela

Polimery

|

2024

|

Vol. 69, nr 4

211--222

EN

The study examined the influence of selected inorganic fillers (5 and 10% by mass) on the foaming process, physicochemical properties, and structure of self-extinguishing polyurethane foam (density of approx. 35 kg/m3) obtained by reacting polyol with isocyanate (100:110). The filler used was bentonite (B), lamellar graphite (G), dendritic copper (Cu), aluminum oxide (Al2O3) and silicon carbide (SiC) and Al2O3/SiC mixture (1:1). Stereoscopic microscopy was used to determine the structure. The functional properties were examined based on density, water absorption and fire resistance. The course of the foaming reaction depends on the content, type and physicochemical properties of the filler. The addition of bentonite increases water absorption and Al2O3 reduces flammability of the foam.

PL

W pracy zbadano wpływ wybranych napełniaczy nieorganicznych (5 i 10 % mas.) na proces spieniania, właściwości fizykochemiczne i strukturę samogasnącej pianki poliuretanowej (gęstość ok. 35 kg/m3), którą otrzymano w wyniku reakcji poliolu z izocyjanianem (100:110). Jako napełniacza użyto bentonitu (B), grafitu o budowie lamelarnej (G), miedzi o strukturze dendrytycznej (Cu), tlenku glinu (Al2O3) i węglika krzemu (SiC) oraz mieszaninę Al2O3/SiC (1:1). Do oceny struktury stosowano mikroskopię stereoskopową. Właściwości użytkowe oceniano na podstawie gęstości, absorpcji wody i odporności na ogień. Przebieg reakcji spieniania zależy od zawartości, rodzaju i właściwości fizykochemicznych napełniacza. Dodatek bentonitu zwiększa absorpcję wody, a Al2O3 zmniejsza palność pianki.

6

Studying the influence of selected controlled factors on the coefficient of sliding friction through experimental planning metho

Ahmedov Beyali, Aslanov Zabit

Nafta-Gaz

|

2024

|

R. 80, nr 1

30--38

EN

The article presents the use of mathematical statistics to determine controllable factors that influence the coefficient of friction in a dual-flow three-stage spur gear transmission of a newly designed sucker rod pumping unit. The load acting on the bearing units, the rotational speed of the main and auxiliary shafts, and the diametrical gap between the shaft and the bushing were assessed through tests. The tests were carried out in random order. The multivariate testing was used to determine the number of tests to be performed as well as the test conditions in order to achieve the required accuracy bushing. In the statistical analysis of the results, the Cochrane criterion was applied to verify the homogeneity of the variance values. Student's t-test was used to verify the significance of the coefficients included in the regression equation, Fisher’s F-test was used to determine the suitability of the adopted output function for describing the real object of study, i.e., the adequacy of the model, and sensitivity coefficients were used to assess the influence of the corresponding parameters on the optimization parameter. The analysis also considered the dispersion of optimization parameters, measurement repeatability, and errors in the model coefficients. Experimental values of the criteria, along with the dispersion of the adequacy and repeatability of the mathematical model, were evaluated to determine whether the model is fully suitable for the object of study. The impact of significant factors and their combinations, as well as their critical values, were assessed by comparing calculated values of the criteria. The significance or insignificance of the corresponding coefficients of the regression equation was determined. To investigate the impact of these controlled factors — load, rotational speed of the main and auxiliary shafts, and the diametrical gap between the auxiliary shaft and the bushing — on the sliding friction coefficient, a modernized device was developed. This device simulates the operating conditions of a double friction sliding bearing in a dual-flow, three-stage spur gearbox bushing. The experiments were conducted using I-40A industrial oil at room temperature. It has been determined that these factors significantly impact the coefficient of friction in a double friction bearing. Consequently, it is necessary to calculate their limit values to ensure the bearing assembly operates without failure during the required service life. Compared to other examined parameters, the optimization parameter, i.e., the coefficient of friction, is most significantly influenced by the diametrical gap between the auxiliary shaft and the bushing, and least affected by the magnitude of the load acting on the bearing assembly. The overall impact of controlled factors on the coefficient of friction is minimal. Employing the test planning method, a mathematical formula was derived, enabling the determination of the coefficient of friction in a double sliding friction bearing without additional tests within the range of limit bushing values of contact parameters.

PL

W artykule przedstawiono zastosowanie statystyki matematycznej do określenia sterowalnych czynników wpływających na współczynnik tarcia w podwójnej, trójstopniowej przekładni zębatej czołowej nowo zaprojektowanej pompy żerdziowej. Za pomocą badań oceniono obciążenie działające na zespoły łożyskowe, prędkość obrotową wału głównego i pomocniczego oraz średnicę szczeliny między wałem a tuleją. Badania przeprowadzono w losowej kolejności. Badania wielowariantowe wykorzystano do określenia liczby badań, które należy wykonać, a także warunków badawczych w celu osiągnięcia wymaganej dokładności. W analizie statystycznej wyników zastosowano kryterium Cochrane'a w celu weryfikacji jednorodności wartości wariancji. Test t-Studenta posłużył do weryfikacji istotności współczynników zawartych w równaniu regresji, test F-Fishera wykorzystano do określenia przydatności przyjętej funkcji wyjściowej do opisania rzeczywistego obiektu badań, tj. adekwatności modelu, a współczynniki wrażliwości wykorzystano do oceny wpływu odpowiednich parametrów na parametr optymalizacyjny. W analizie uwzględniono również rozrzut parametrów optymalizacyjnych, powtarzalność pomiarów oraz błędy we współczynnikach modelu. Eksperymentalne wartości kryteriów, wraz z rozproszeniem adekwatności i powtarzalności modelu matematycznego, zostały ocenione w celu ustalenia czy model w pełni spełnia wymagania stawiane obiektowi badań. Wpływ istotnych czynników i ich kombinacji, a także ich wartości krytyczne, oceniono poprzez porównanie obliczonych wartości kryteriów. Określono istotność lub nieistotność odpowiednich współczynników równania regresji. W celu zbadania wpływu tych kontrolowanych czynników – obciążenia, prędkości obrotowej wału głównego i pomocniczego oraz szczeliny średnicowej pomiędzy wałem pomocniczym a tuleją – na współczynnik tarcia ślizgowego, opracowano zmodernizowane urządzenie. Urządzenie to symuluje warunki pracy podwójnego łożyska ślizgowego w podwójnej, trzystopniowej przekładni czołowej. Eksperymenty przeprowadzono przy użyciu oleju przemysłowego I-40A w temperaturze pokojowej. Ustalono, że czynniki te mają znaczący wpływ na współczynnik tarcia w podwójnym łożysku ślizgowym. W związku z tym konieczne jest obliczenie ich wartości granicznych, aby zapewnić bezawaryjną pracę zespołu łożyskowego w wymaganym okresie eksploatacji. W porównaniu z innymi badanymi parametrami, na parametr optymalizacyjny, tj. współczynnik tarcia, największy wpływ ma szczelina średnicowa między wałem pomocniczym a tuleją, a najmniejszy wpływ ma wielkość obciążenia działającego na zespół łożysk. Ogólny wpływ kontrolowanych czynników na współczynnik tarcia jest minimalny. Wykorzystując metodę planowania badań, wyprowadzono wzór matematyczny umożliwiający wyznaczenie współczynnika tarcia w podwójnym ślizgowym łożysku bez dodatkowych badań w zakresie granicznych wartości parametrów styku.

7

Dispersion of Methane in Closed Enclosures

Cioclea Doru, Ianc Nicolae, Boanta Corneliu, Matei Adrian, Dragoescu Razvan

Inżynieria Mineralna

|

2024

|

Vol. 1, no. 1

263--274

EN

The increase of the population also involve the increase of the consumption of raw materials. This requires the diversification and development of industrial processes in semi-enclosed or open spaces. The carrying out of human activities of an industrial nature involves the accidental use, handling or presence of explosive substances such as methane. The presence of this gas in closed or semi-closed spaces can generate explosion phenomena. The accumulation of methane in narrow spaces is well studied and known, but the dispersion and especially the dispersion dynamics of methane released from a source considered infinite is less known. Knowing how methane disperses into the air is very important for establishing preventive measures. The paper presents the experiment on the dynamics of methane dispersion in a closed enclosure.

8

Applying the expert method to determine a company’s strategic goals

Satybaldiyeva Dinara, Mukhanova Gulmira, Tymbayeva Zhazira, Tyshkanbayeva Mansiya, Bolatkyzy Saltanat

Transport Problems

|

2023

|

T. 18, z. 2

123--132

EN

The most important factor for the success of a company in today’s competitive environment is to have clearly defined goals. Objectives define what a company strives for, what it wants to achieve, and what it wants to realize in its activities. Clearly defined goals are necessary to ensure the sustainability and effectiveness of a company’s operations and the successful achievement of its desired results. This paper proposes an expert method for determining the strategic goals of a company. The experts ranked 24 strategic goals in terms of importance, and variance and coefficient of variation were then used to determine the consistency of the experts. As a result, 15 important strategic goals were identified of the 24 goals of the assessed transport company.

9

Effect of ethanol-assisted mixing on the selected properties and homogeneity of NR/BR blends

Meng Chao, Gu Zheng, Sui Jinyong, Wang Jianfa, Li Peiyao, Hu Shaokai, Zhang Susu, Zhang Xiaoyi, Wang Haoyu, Han Shaolong, Yang Zhifei

Polimery

|

2023

|

Vol. 68, nr 3

142--148

EN

The effect of the mixing method (normal and ethanol-assisted) on selected properties of natural rubber with butadiene rubber blends (NR/BR 80/20) was investigated. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) were used to evaluate the properties. In addition, the mechanical tensile properties, tear resistance and thermal aging, as well as vulcanization characteristic were determined. It was found that ethanol-assisted mixing can significantly improve the mechanical properties and thermal stability of the blends as a result of better dispersion of additives in the rubber matrix.

PL

Zbadano wpływ metody mieszania (tradycyjna i wspomagana etanolem) na wybrane właściwości mieszanin kauczuku naturalnego z kauczukiem butadienowym (NR/BR 80/20). Do oceny właściwości zastosowano skaningową mikroskopię elektronową (SEM), spektroskopię w podczerwieni z transformacją Fouriera (FTIR) oraz analizę termograwimetryczną (TGA). Ponadto oznaczono właściwości mechaniczne przy rozciąganiu, odporność na rozdzieranie i starzenie termiczne, a także właściwości wulkanizacyjne. Stwierdzono, że mieszanie wspomagane etanolem może znacząco poprawić właściwości mechaniczne i stabilność termiczną mieszanin NR/BR, jako efekt lepszej dyspersji dodatków w osnowie gumowej.

10

Successive dispersion, amalgamation and accretion of terranes of Myanmar from the Gondwana

Aung Hla Hla

Geotourism / Geoturystyka

|

2023

|

nr 1-2 (72-73)

12--13

EN

Myanmar represents an evolving continent of two crustal formation histories consisting of the Burma plate and the Indochina plate. The Burma plate (western part of Myanmar) consists of three distinct lithotectonic entities: 1) a continental fragment, 2) a subduction-related accreted complex (NeoTethys suture zone) in the westernmost part of Myanmar and 3) a coastal area. Eastern Myanmar that is western continuation of Indochina plate is composed of three tectonostratigraphic terranes: 1) Shan boundary belt (Meso-Tethys suture zone) in the western edge of Indochina plate, 2) Sibumasu terrane, 3) the Than Lwin Belt (Paleo-Tethys suture zone) in the easternmost part of Myanmar. The Than Lwin Belt is a tectonic linkage between Inthanon Zone of West Thailand in the south and Changning-Menglian belt of West Yunnan in the north (Aung, 2009). Shan Boundary Belt of Meso-Tethys suture in the western edge of Indochina plate extend to the south to Malay Peninsula. The Rakhine Western Ranges of Neo-Tethys suture at the westernmost part of Myanmar is a northern continuation of Andaman-Nicobar belt. Story of the Tethys is the story of extinctions of sea and telling that story was learned from clues in rocks and fossils. Biostratigraphic correlation between the known distribution of dominant Mesozoic representatives of Monotis, Halobia, and Daonella fauna and microfossil assemblages of Triassic age from Myanmar are made with those from neighboring countries of SE Asia for reconstruction of tectonic terranes for Myanmar. The terranes in Myanmar may have originated in Gondwana in Paleozoic (Figs 1, 2). The accretionary episodes which ended in early Tertiary, have been followed by post-accretionary deformation of strike- slip faulting of the Sagaing Fault in Myanmar; West Andaman Fault and Sumatra Fault System in Sumatra; and spreading in Andaman backarc basin. To reconstruct the palaeogeography of Myanmar terranes distribution of Mesozoic representatives of Monotis, Halobia, and Daonella faunas and Tethyan fusulinids are used. Various species of thin-shelled pectinacid bivalves of Triassic faunas are dominant family and occur in open-marine strata of allochthonous accretionary terranes. These strata are related to different parts of single ocean: Tethys, palaeoequatorial ocean populated by these faunas containing Tethyan fusulinids. Their occurrences in mudstones, sandstones, shale and limestone are very important for Triassic sedimentary succession as diagnostic fossils. Distribution of these faunas and biogeographic studies are an importance in reconstructing post-Triassic intraoceanic plate boundaries and motion. Distribution of these faunas in Triassic marine strata of Shan Massif and correlation with those of neighboring terranes of Asia gave the evidences that Shan Massif was a part of Gondwana in Carboniferous-Permian time facing Paleo-Tethys Ocean. Shan Massif probably separated from Gondwana in Early Triassic time and moved northward from equatorial position. Ophiolites thrusted onto Mesozoic sequences of Halobia shales in pre-Middle Eocene (Rangin, 1996–1999). Their position above the metasedimentary rocks is similar to the Halobia shales of Sumatra which also lies on top of metasedimentary rocks of Permo-Carboniferous Sequences (Bender, 1983). All the Tertiary sequences of Central Myanmar Basin are considered to be deposited on the underlying Burma plate as basement. Initial collision between India and Burma plate in middle Eocene (45–35-Ma) and hard collision during Oligocene to Miocene (23 Ma) and Rakhine Western Ranges became uplifted during Middle Miocene to Late Miocene (Curray, 2005) by thrusting the remnants of NeoTethys sea floor and trench deposits to become Rakhine accretionnary wedge and ophiolites belt at the western part of Burma plate.

11

Measurement of the surface reflectance of an acoustic wave using wave packets propagating in a circular waveguide

Wrzeciono Piotr, Szymański Michał

Vibrations in Physical Systems

|

2022

|

Vol. 33, nr 2

art. no. 2022218

EN

The main idea of the measurement presented in this paper was to separate the incident wave from the reflected wave. For this purpose, short wave packets and a sufficiently long waveguide with a circular cross-section were used. Several types of wave packets were developed and used in the experiment. We found that a wave packet of 5 ms duration could be propagated in a waveguide of length 5.6 meters without significant sound level losses. We used an audio interface operating at a sampling rate of 96 kHz in the measurements. The limit of wave propagation without dispersion phenomenon was determined. The developed measurement methodology made it possible to maintain the same air temperature along the entire length of the tested waveguide since short pulses did not cause the speaker temperature to rise. Avoiding this effect reduced the measurement uncertainty of the reflection coefficient.

12

Contaminant transport in the surf zone

Chin David A.

Oceanologia

|

2022

|

No. 64 (4)

651--664

EN

Dispersion of dissolved contaminants introduced at various locations within and just outside the surf zone are investigated. It is shown that the Longuet-Higgins model of surf-zone hydrodynamics adequately describes the distribution of longshore currents measured at the laboratory scale. Relations are derived between the longitudinal and transverse dispersion coefficients and the influencing parameters. The maximum longitudinal dispersion coefficients are associated with tracer releases near the breaker line, and longitudinal dispersion coefficients generally increase with travel time for distances up to at least 10 surf-zone widths. In contrast, transverse dispersion coefficients remain relatively constant for increasing travel time. The longitudinal and transverse dispersion coefficients can be significantly influenced by assumed values of local turbulent diffusion and cross-shore shear dispersion.

13

Influence of the numerical modelling methods on dispersions and errors of analysis results of ship hull and deckhouse vibrations

Murawski Lech

Journal of KONBiN

|

2022

|

Vol. 52, iss. 4

207--222

EN

Ships' (especially containers) vibrations significantly impact navigation safety. The presented analyses aims to identify the main forces exciting the ship's superstructure and hull vibrations, test their influence on vibration levels, and verify the assumptions of the computational methodology. Two container ships were analysed. The influence of different modeling methods on the obtained calculation results was investigated. The impact of various operating parameters on the vibration level was also analysed. The numerical analyses results are compared with some empirical formulas. As a result, the calculation confidence level was estimated. The calculation results have been verified by comparison with measurement tests carried out on the real ship.

PL

Drgania statków (zwłaszcza kontenerowców) mają duży wpływ na bezpieczeństwo żeglugi. Celem przedstawionych analiz jest identyfikacja głównych sił wymuszających drgania nadbudówki i kadłuba statku, zbadanie ich wpływu na poziom drgań oraz weryfikacja założeń metodyki obliczeniowej. Przeanalizowano dwa kontenerowce. Zbadano wpływ różnych metod modelowania na wyniki obliczeń. Przeanalizowano również wpływ różnych parametrów eksploatacyjnych na poziom drgań. Wyniki analiz numerycznych porównano z niektórymi wzorami empirycznymi. W rezultacie oszacowano poziom ufności obliczeń. Wyniki obliczeń zostały zweryfikowane poprzez porównanie z badaniami pomiarowymi wykonanymi na rzeczywistym statku.

14

Deep-neural-networks-based approaches for Biot-squirt model in rock physics

Xiong Fansheng, Liu Jiawei, Guo Zhenwei, Liu Jianxin

Acta Geophysica

|

2022

|

Vol. 70, no 2

593--607

EN

A new cost-effective surrogate model using deep neural network (DNN) for seismic wave propagation in rocks saturated with fluid is presented. In this field, the dispersion/attenuation analysis and wave-field simulation are two key measurements which can be carried out by solving wave equations. The Biot–squirt (BISQ) equation is a classical wave propagation model in geophysical forward modeling and has been widely used. The solution of such equation, especially by numerical method, is often complex and time-consuming. In this work, a DNN model is trained with the dataset of velocity and inverse quality factor generated from BISQ model. The results show that the relative mean square error between the predictions of DNN model and that of BISQ model on the test sets are all less than 3%. It indicates that the DNN model has learned the high-dimensional space well and then can realize the dispersion/attenuation analysis for any given rock physical parameters. Besides, the other well-trained DNN model is used to obtain the simulation results with second-order accuracy according to results by finite difference scheme with first-order accuracy. It reveals that the fast wave-field simulation can be implemented once the results with lower accuracy are obtained.

15

An introduction of the planetary roller extruder technology on the example of the wood-plastic composites production

Sąsiedzki Tad

Modelowanie Inżynierskie

|

2021

|

T. 42, nr 73

42--47

EN

Planetary roller extruder with his excellent mass temperature control, homogenization and dispersion is used not only in the plastics industry, but in a wide range of physical processes like continuous mixing, reactive chemical processes as polymerization and decomposition, for example in the process of recycling. ENTEX developed in last few years new improved technical solutions for example for better degassing, higher torque transmission, laboratory applications and direct extrusion. With these new solutions we create significant cost savings due to reduction of energy consumption and reduction of production costs by simplifying production process. We can also improve final product quality by reducing the thermal and mechanical load on the material on the example of WPC composite (Wood-Plastic-Composites).

PL

Rynek kompozytów WPC stale rośnie i otwiera potencjał dla nowych producentów i nowych technologii. Również firma ENTEX Rust & Mitschke GmbH podjęła wyzwanie i oferuje swoją technologię mieszalnika planetarnego do wyżej wymienionych zastosowań. Ze względu na dużą powierzchnię styku, wysoce wydajne i precyzyjne możliwości ogrzewania lub chłodzenia przetwarzanego materiału oraz modułową budowę wytłaczarka planetarna jest w stanie uzyskać do 78% wypełnienia wiórkami drzewnymi w polimerze przy zachowaniu najwyższej jakości produktu końcowego.

16

Simulation of photovoltaic panel cooling beneath a single nozzle based on a configurations framework

Mzad Hocine, Otmani Abdessalam

Archives of Thermodynamics

|

2021

|

Vol. 42, no. 1

115--128

EN

Solar cell performance decreases with increasing temperature, heat can reduce output efficiency by 10–25%. The operating temperature plays a key role in the photovoltaic conversion process. Increase in electrical efficiency depends on cooling techniques, in particular photovoltaic modules installed in the high temperature regions. A cooling process using a single nozzle of photovoltaic panel operating under different configurations was simulated. The simulation contains two parts: the first is a thermodynamic investigation of fluid impingement upon the sensor front face. The second is a performance comparison between two types of glass cover. The major result that emerges from this simulation is the effect of a single nozzle arrangement to enhance the cooling process, under a low cadence of impinging droplets in the range 0.1–1.7 m/s.

17

A quadrature-free Legendre polynomial approach for the fast modelling guided circumferential wave in anisotropic fractional order viscoelastic hollow cylinders

Zhang X., Liang S., Shao S., Yu J.

Archives of Mechanics

|

2021

|

Vol. 73, nr 2

121--152

EN

Compared to the traditional integer order viscoelastic model, a fractional order derivative viscoelastic model is shown to be advantageous. The characteristics of guided circumferential waves in an anisotropic fractional order Kelvin–Voigt viscoelastic hollow cylinder are investigated by a quadrature-free Legendre polynomial approach combining the Weyl definition of fractional order derivatives. The presented approach can obtain dispersion solutions in a stable manner from an eigenvalue/eigenvector problem for the calculation of wavenumbers and displacement profiles of viscoelastic guided wave, which avoids a lot of numerical integration calculation in a traditional polynomial method and greatly improves the computational efficiency. Comparisons with the related studies are conducted to validate the correctness of the presented approach. The full three dimensional spectrum of an anisotropic fractional Kelvin–Voigt hollow cylinder is plotted. The influence of fractional order and material parameters on the phase velocity dispersion and attenuation curves of guided circumferential wave is discussed in detail. Moreover, the difference of the phase velocity dispersion and attenuation characteristics between the Kelvin–Voigt and hysteretic viscoelastic models is also illustrated. The presented approach along with the observed wave features should be particularly useful in non-destructive evaluations using waves in viscoelastic waveguides.

18

An influence of the covariance between single orbit parameters on the accuracy of observations of the pseudo-ranges and phase differences

Skeivalas Jonas, Paršeliūnas Eimuntas, Putrimas Raimundas, Šlikas Dominykas

Metrology and Measurement Systems

|

2020

|

Vol. 27, nr 1

131--140

EN

The possibilities to improve values of the satellite orbit elements by employing the pseudo-ranges and differences of carrier phase frequencies measured at many reference GPS stations are analysed. An improvement of orbit ephemeris is achieved by solving an equation system of corrections of the pseudo-ranges and phase differences with the least-squares method. Also, equations of space coordinates of satellite orbit points expressed by ephemeris at fixed moments are used. The relation between the accuracy of the pseudo-ranges and phase differences and the accuracy of the satellite ephemeris is analysed. Formulae for estimation of the influence of the ephemeris on the measured pseudo-ranges and phase differences and for prediction of the accuracy of the pseudo-ranges and phase differences were obtained. An influence of the covariance between single orbit parameters on the accuracy of the pseudo-ranges and phase differences is detected.

19

Investigating Sintering Behavior of the Graphene Nanoplatelets (GNPs) Reinforced Aluminum Nanocomposites Via Low Energy Solution Ball Milling

Baig Zeeshan, Mamat Othman, Mustapha Mazli, Ali Sadaqat

Archives of Metallurgy and Materials

|

2020

|

Vol. 65, iss. 2

755--759

EN

Owing to the excellent properties, graphene nanoplatelets (GNPs) show great reinforcing ability to improve the mechanical and tribological properties of Al nanocomposites for many automotive applications. In this work, the GNPs dispersion and reinforcing effect in Al nanocomposite was tested. Solvent dispersion via tip sonication and facile low energy ball milling (tumbling milling) using two milling speeds 200 and 300 rpm were employed to develop GNPs/Al powders. Sintering response of the GNPs/Al sintered samples wasgauged at two temperatures (550°C and 620°C). The effects of GNPs content, milling rotation speed and sintering temperature on the density, hardness and wear properties of the nanocomposite were examined. The results indicate that relative density % decreases with increasing GNPs content due to possible reagglomeration. The highest hardness of 35.6% and wear rate of 76.68% is achieved in 0.3 wt.% GNPs/Al nanocomposite processed at 300 rpm and 620°C as compared to pure Al due to uniform dispersion, higher diffusion rate at a higher temperature and effective lubrication effect.

20

Impact of ground adsorption capacity on the change in chemical composition of groundwater

Aniszewski Andrzej

Archives of Environmental Protection

|

2020

|

Vol. 46, no. 2

35--41

EN

Demonstrating the impact of time-dependent ground adsorption capacity on the change in chemical composition of groundwater is an important issue in understanding the groundwater mass transport process. Commonly used parameters characterizing ground adsorption capacity (Ra, ux* = ux/Ra, Δ C*max) were analyzed in this work to demonstrate time-varying values of this capacity for a chosen type of ground. Analysis of values of the selected parameters showed a gradual time decline in ground adsorption capacity as well as a gradual increase of groundwater contamination. This gradual increase in groundwater contamination over time is also important in practice. It implies the necessity to use more and more advanced (expensive) methods of water treatment in groundwater intakes.

PL

Wykazanie wpływu zależnej od czasu pojemności adsorpcyjnej gruntu na zmianę składu chemicznego wód podziemnych jest ważnym zagadnieniem w zrozumieniu procesu transportu masy wód podziemnych. W niniejszej pracy przeanalizowano powszechnie stosowane parametry charakteryzujące pojemność adsorpcyjną gruntu (Ra, ux* = ux/Ra, Δ C*max ), aby wykazać zmienne w czasie wartości tej pojemności. Dokładna analiza wartości liczbowych wybranych parametrów wykazała spadkową w czasie tendencję pojemności adsorpcyjnej gruntu, a także stopniowy wzrost zanieczyszczenia wód gruntowych. Ten stopniowy w czasie wzrost zanieczyszczenia wód gruntowych jest również ważny w praktyce. Wiąże się bowiem z koniecznością stosowania coraz bardziej zaawansowanych (kosztownych) metod uzdatniania wód podziemnych pobieranych z ujęć.