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1

Preservatives in fruit jams

Żmuda-Czerwonka Wioletta

Polish Technical Review

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2023

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No. 1

18--20

EN

The modern human diet is the subject of research and interest for a large group of specialists. The unlimited capabilities of synthesising new chemical substances and the far-reaching changes in legislation create a space for expanding the list of permissible food additives. Despite the research conducted on new substances, the consumers are afraid that not all additives are sufficiently safe. This is frequently due to lack of access to objective and scientifically-verified information. The most concern is caused by the use of multiple additives in the same food product, which increases the risk of their accumulation in the human body. The objective of this paper is to discuss preservatives added to jams. It involves a discussion of the technological process and indicates the moment that a given preservative is added, showing photographs and findings from an experiment conducted on a single type of jam. The experiment was conducted under domestic conditions.

PL

Dieta współczesnego człowieka to przedmiot badań i zainteresowania dużej grupy specjalistów. Nieograniczone możliwości syntezy nowych substancji chemicznych i daleko idące zmiany w ustawodawstwie dają pole do rozszerzania listy dopuszczalnych dodatków do żywności. Pomimo badań nad nowymi substancjami istnieje obawa konsumencka, że nie wszystkie dodatki do żywności są wystarczająco bezpieczne. Jest to często wynikiem braku obiektywnych i potwierdzonych naukowo informacji. Najwięcej obaw budzi stosowanie wielu dodatków w jednym produkcie spożywczym, a to zwiększa ryzyko ich kumulacji w organizmie człowieka. Założeniem artykułu jest przybliżenie jakie substancje konserwujące pojawiają się w dżemach. Przedstawienie procesu technologicznego i wskazanie momentu kiedy dana substancja konserwująca jest dodawana oraz przedstawienie zdjęć i wniosków z doświadczenia jakiemu poddano jeden rodzaj dżemu. Doświadczenie to wykonano w warunkach domowych.

2

Study on the influence of chamfer perforation on heave and pitch of a single floating platform

Wang Wei, Fan Sheming, You Yunxiang, Zhao Cheng, Xu Liqun, Wang Guibiao, Lu Zhiqiang

Polish Maritime Research

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2023

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nr 1

43--53

EN

The aim of this work is to study the influence of chamfered perforation and chamfering on the heave and pitch motion of a single floating wind power platform with an anti-heave device. Firstly, the hydrodynamic performance of a single floating body with different chamfers, or without perforation, is calculated and analysed. Secondly, the motion of a model without perforation and with 35° chamfered perforation is captured and studied in a towing tank. The results show that when the wave height is large and the period is small, the perforated device has a certain effect. When the wave height and period are small, the pitch suppression effect of chamfered perforation is more obvious than that of non-chamfered perforation. When the period and wave height are large, the heave suppression effect of non-chamfered perforation is better than that of chamfered perforation. In experimental research, the perforated floating body has a certain effect on restraining the heave and pitch of a floating body under most working conditions, and the effect of restraining the pitch is obviously better than that of restraining the heave.

3

Experimental identification of the force and moment characteristic of symmetrically and non-symmetrically profiled annular seals

Kuhr Maximilian M. G., Pelz Peter F.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2023

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Vol. 71, nr 6

art. no. e147062

EN

In modern turbomachinery, the performance and reliability is often limited by shaft vibrations induced by fluid film forces and moments of (i) plain or (ii) profiled annular seals. Therefore, these narrow annuli are mainly responsible for the overall system behaviour, i.e. safe operation and maintenance intervals. However, many studies focus only on the characteristics from the forces due to the translational motion, although the influence of the rotordynamic tilt and moment coefficients is well known. Therefore, these additional coefficients are much less researched. Especially, for profiled seals, the availability of reliable experimental data for validation purpose is rare. To overcome this fact, a test rig is operated at the Chair of Fluid Systems at the Technische Universität Darmstadt. The generic experiments presented here investigate the force and moment characteristic of plain, symmetrically profiled and non-symmetrically profiled annular seals within the relevant parameter range for turbulent flows in pumps. The investigations focus on the influence of the annulus length as well as the pressure difference across the annulus.

4

Multi-Variant Analysis of the Cross Wedge Rolling Process for Producing Railcar Axles

Pater Zbigniew, Tomczak Janusz, Bulzak Tomasz Adam

Advances in Science and Technology. Research Journal

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2023

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Vol. 17, no 5

208--219

EN

This study investigates the cross wedge rolling (CWR) process for manufacturing a rail axle in a scale of 1:6. Three cases of the rolling process are modelled numerically: standard rolling, wasteless rolling and rolling from a preform. The rolling cases under analysis are compared in terms of material and energy consumption, forming loads as well as propensity to internal and external defect formation. Using the Cockcroft-Latham criterion and the limits of this criterion determined by the rotary compression test, an assessment was made of the propensity of the material to fracture during the rolling processes analysed. Based on numerical results, standard CWR is selected for experimental verification. Obtained experimental results confirm that CWR is an effective method for producing railcar axles that are free from both internal and external defects. The experimental and numerical results obtained confirm that cross wedge rolling technology can be successfully used under industrial conditions for the production of long axles or shafts.

5

Stability investigation of the pcm nanocomposites

Cieśliński Janusz T., Boroń Paulina, Fabrykiewicz Maciej

Acta Mechanica et Automatica

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2023

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Vol. 17, no. 3

381--389

EN

Ensuring the stability is a key issue to be solved for the technical application of nanocomposites. In this work, fatty acid P1801 served as base phase change material (PCM)P1801, and its main ingredients are palmitic acid (58%) and stearic acid (38%). Titania (TiO2) and alumina (Al2O3) with mass concentrations of 1% and 5% were selected as nanoparticles, while polyvinylpyrrolidone (PVP) or oleic acid (OA) with mass concentrations of 5% were tested as surfactants. On the basis of the measured temperature distributions in the sample, which is subject to melting and solidification processes, it was determined which of the tested nanocomposites are stable and which are not. In addition, a thermal test was proposed to assess the stability of the produced nanoPCM, which consists in measuring the temperature distribution versus time according to a precisely given procedure.

6

Krajobraz i jego ocena w ujęciu fenomenologicznym

Bonenberg Wojciech

Zeszyty Naukowe Politechniki Poznańskiej. Architektura, Urbanistyka, Architektura Wnętrz

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2022

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Z. 8

31--41

PL

Artykuł ma charakter eksperymentu okazjonalnego prezentującego fenomenologiczne podejście do badań krajobrazu oraz przykład krytycznej ich oceny z punktu widzenia wartości, jakie badania te wnoszą do dyscypliny naukowej architektura i urbanistyka.

EN

The article has the character of an occasional experiment presenting a phenomenological approach to landscape research. Particular attention has been paid to the usefulness of such methodological instruments for assessing landscape context in architecture and urban planning

7

Model of the city

Słyk Jan

Przestrzeń i Forma

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2022

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nr 50

55--64

EN

The design and development of cities is the most complicated phenomenon in the domain of shaping space. It is the result of planned human activities related to land parcellation, building infrastructure, establishing safety rules, creating a friendly scale and aesthetics of public spaces. It is also the result of spontaneous processes that take place without strict control. It is influenced by economy, demography, environmental factors, as well as wars, conflicts, and competition between entities. In architecture, it is possible to build knowledge and competences by performing tests on a 1:1 scale. Although expensive and difficult, it sometimes brings the desired results and opens the perspective to new design techniques. In urban planning, the subject of creative activities is too complex to test final solutions. The time from design to implementation is too long to use your own experience even indirectly. The only way to test urban ideas in the conceptual phase is to create models. Both geometric and social features could be represented. The most perfect contemporary models attempt to comprise many processes of city functioning, including spontaneous activities conditioned by external and internal factors.

PL

Proces powstawania i rozwoju miast jest najbardziej skomplikowanym zjawiskiem w obszarze zagadnień przestrzennych. Jest wynikiem planowych działań człowieka dotyczących podziału gruntu na parcele, budowy infrastruktury, tworzenia zasad bezpieczeństwa, kreowania przyjaznej skali i estetyki wnętrz publicznych. Jest także rezultatem spontanicznych procesów toczących się bez ścisłej kontroli. Mają na nie wpływ ekonomia, demografia, czynniki środowiskowe, a także wojny, spory, rywalizacja podmiotów. W architekturze możliwe jest budowanie wiedzy i kompetencji poprzez wykonywanie prób w skali 1:1. Choć kosztowne i trudne, przynosi niekiedy pożądane rezultaty i otwiera drogę ku nowym technikom projektowania. W urbanistyce, przedmiot działań twórczych jest zbyt złożony, aby testować gotowe rozwiązania. Czas upływający od projektu do realizacji jest zbyt długi, aby nawet pośrednio korzystać z własnych doświadczeń przy kolejnych próbach. Jedynym sposobem testowania rozwiązań urbanistycznych w fazie koncepcyjnej jest tworzenie modeli. Reprezentowane są w nich zarówno cechy geometryczne jak i społeczne. Najdoskonalsze współczesne modele starają się uwzględniać wiele procesów funkcjonowania miast, w tym również procesy spontaniczne uwarunkowane przez czynniki zewnętrzne i wewnętrzne.

8

Quantitative assessment of the influence of plasma hardfacing parameters on the metallurgical melting of an austentic steel coating with a substrate material made of C45 steel

Bazychowska Sylwia, Starosta Robert, Dudzik Krzysztof

Journal of KONBiN

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2022

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Vol. 52, iss. 3

27--51

EN

In this paper, based on a quantitative analysis of the parameters of plasma hardfacing of C45 steel with CastoMag 45554S wire, an optimisation of the hardfacing process parameters has been carried out. Experimental researches were carried out on the basis of an orthogonal plan, and the optimum hardfacing parameters, e.g.: intensity, voltage, wire feeding speed, were determined by the multiple regression method and the Taguchi method. It was found that the main current of the plasma arc had the greatest influence on the value of the fusion index. The highest S/N value was obtained for the following parameters: I = 120 A, U = 31 V, vn = 0.75 m/min, vd = 3.9 m/min, z = 12 mm.

PL

W oparciu o ilościową analizę parametrów napawania plazmowego stali C45 drutem CastoMag 45554S dokonano optymalizacji parametrów procesu napawania. Badania realizowano na podstawie planu ortogonalnego, a optymalne parametry napawania np.: natężenie, napięcie, prędkość podawania drutu zostały wyznaczone metodą regresji wielokrotnej oraz metodą Taguchi. Ustalono, że największy wpływ na wartość współczynnika wtopienia ma natężenie prądu głównego łuku plazmowego. Największą wartość współczynnika S/N uzyskano przy parametrach: I = 120 A, U = 31 V, vn = 0,75 m/min, vd = 3,9 m/min, z = 12 mm.

9

Digital image stabilization for the experimental verification of object motion trajectories

Piątkowski Tomasz

Journal of Automation, Electronics and Electrical Engineering

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2022

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Vol. 4, No. 2

23--30

EN

The article presents digital stabilization procedure of the image recorded with a camera performing unintentional spatial movement in relation to the scene. This method consists in carrying out translational and rotational transformations and scaling all frames in relation to the first frame, using the tools of the Matlab environment. The image stabilization procedure allows to effectively improve the image to make it suitable for the analysis of the tracked objects trajectories on the scene, observed from the camera located on the rotor drone.

PL

W artykule przedstawiono procedurę cyfrowej stabilizacji obrazu zarejestrowanego kamerą wykonującą niezamierzony ruch przestrzenny względem sceny. Metoda ta polega na przeprowadzeniu transformacji translacyjnej, obrotowej i skalowaniu wszystkich kadrów względem kadru pierwszego, wykorzystując narzędzia środowiska Matlab. Procedura stabilizacji obrazu pozwala skutecznie uzdatnić obraz, by nadawał się on do analizy torów ruchu śledzonych obiektów na scenie, obserwowanej z kamery umieszczonej na dronie wirnikowym.

10

The Use of GFRP Tubes as Load-Bearing Jackets in Concrete-Composite Columns

Abramski Marcin, Chmielnicki Błażej

Civil and Environmental Engineering Reports

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2022

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Vol. 32, no. 2

96--117

EN

The paper presents the fields of applications of polymer composites in building structures. The use of composite glass fibre tubes is discussed in more detail. The laboratory methods used to test the mechanical properties of these pipes are presented. An original research program is presented, including six concrete-filled glass fibre tubes. The cylinders and columns made in this way were tested for their axial load capacity. Conclusions were formulated regarding the relationship between the load-bearing capacity of the test elements and their length, as well as the angle of glass fibres arrangement in the tube composite.

11

Science curiosities cabinet and the chemical showcase

Szydło Zbigniew A.

Chemistry-Didactics-Ecology-Metrology

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2022

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R. 27, NR 1-2

79--103

EN

With the drastic reduction of the school chemistry teaching program in England in 1986, large quantities of apparatus and chemicals became redundant. The disused apparatus at Highgate School inspired the construction of a chemical showcase for pupils; this has encouraged pupils to develop a passion for chemistry. The idea of a “miniature museum” came from a visit to a local primary school in London, which had a beautiful science curiosities cabinet in one of its rooms. In both schools, sciences thrive, and are popular among pupils. Undoubtedly a display of assorted artefacts, which can be readily accessed by pupils, makes a significant impact on developing their interest in science. It is hoped that the story of these ventures will inspire teachers to make their own versions of these excellent and easily constructed educational facilities.

12

Numerical and experimental study on forming preforms in a CNC skew rolling mill

Pater Zbigniew, Tomczak Janusz, Bulzak Tomasz, Walczuk-Gągała Patrycja

Archives of Civil and Mechanical Engineering

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2022

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Vol. 22, no. 1

art. no. e54, 2022

EN

This paper relates to a study on the formation of elongated preforms in a CNC skew rolling mill. First, a numerical analysis was performed to investigate forming processes for three different parts: a scraper, a connecting rod, and a hook. The shapes and dimensions of preforms were designed, and rolling and closed-died forging processes for producing these parts were simulated numerically. Distributions of temperature, effective strain and damage function were determined for rolled preforms. Loads and torques in the rolling process were measured. It was found that the forming process of preforms performed in a CNC skew rolling mill was characterized by relatively low force parameters in relation to the dimensions of formed parts. Numerical simulations of the forging process showed that all forged parts had the required shape, which indicates that the preforms were designed correctly. Following the numerical analysis, experiments were performed in which the preforms were rolled under laboratory conditions (in a scale of 1:2). Experimental results demonstrated that the rolled parts had no internal defects (cracks) and were characterized by high dimensional accuracy.

13

Le domaine de la Terre - the domain of the Earth

Marmur Michał

Zeszyty Naukowe Politechniki Poznańskiej. Architektura, Urbanistyka, Architektura Wnętrz

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2021

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Z. 7

135--148

EN

On November 25, 1985 in Villefontaine, the Domaine de la Terre, a unique res idential area in the world was officially opened. About 600 people moved into 65 social flats, housed in twelve apartment islands designed by 10 teams of architects to experiment with various earth-building techniques. The idea of a earth settlement was born in 1980 in Paris. The aim of the experiment was an international exhibition devoted to the history, current events and the future of clay architecture and other local materials. The project has become a testing ground and a place to put new technical solutions into practice.

PL

25 listopada 1985 roku w miejscowości Villefontaine nastąpiło uroczyste otwarcie wyjątkowej na skalę światową dzielnicy mieszkaniowej we Francji: Domaine de la Terre. Około 600 osób wprowadziło się do 65 mieszkań socjalnych umieszczonych w dwunastu wyspach mieszkalnych zaprojektowanych przez 10 zespołów architektów w celu eksperymentowania z różnymi technikami budownictwa ziemnego. Pomysł osiedla z ziemi narodził się w 1980 roku w Paryżu. Celem eksperymentu była międzynarodowa wystawa poświęcona historii, bieżącym wydarzeniom i przyszłości architektury z gliny i innych materiałów lokalnych. Projekt stał się poligonem doświadczeń oraz miejscem do stosowania w praktyce nowych rozwiązań technicznych.

14

Brasília: Ilha da Fantasia. Krótki szkic o mieście

Malinowska-Petelenz Beata

Środowisko Mieszkaniowe

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2021

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nr 37

26--36

PL

Brasília, fantastyczna wyspa - to jedno z najbardziej niezwykłych miast na świecie, które zostały zaprojektowane od początku i w miejscu starannie wybranym do tego celu. Stolica największego kraju Ameryki Południowej, przestrzeń „oswojona”, która nie istniała jeszcze na początku XX wieku, stanowi kwintesencję myśli modernistycznej przeniesionej na grunt latynoamerykański. Utopijna Brasília miała być miastem marzeń, zdekolonizowaną potęgą, realizacją socjalistycznej ideologii, opus magnum Kubitschka i Costy. Bez slumsów i kolonialnej, historyzującej zabudowy. I choć powstała w latach 60. ubiegłego wieku, nadal budzi skrajne emocje. Jak dziś rozwija się owo urbanistyczne arcydzieło i symbol brazylijskiego modernizmu? Co zostało z wyobrażeń i założeń funkcjonalistów?

EN

Brasília, a fantastic island - one of the world’s most extraordinary cities, designed from the ground up at a site carefully preselected for that specific purpose. The capital of South America’s largest country, a “domesticated” space, which did not exist at the start of the twentieth century, it is a quintessence of Modernist thought transplanted into Latin American soil. The utopian Brasília was to be a city of dreams, a decolonized power, the realization of socialist ideology, an opus magnum for Kubitschek and Costa. Without slums and colonial, historicizing development. And although it was built in the 1960s, it still stirs extreme emotions. How does this urban masterwork and symbol of Brazilian Modernism develop today? What has been left of the expectations and assumptions of the Functionalists?

15

Jeden wypadek - dwa eksperymenty

Ciępka Piotr

Paragraf na Drodze

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2021

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Nr 4

55--71

PL

Wykorzystując zdarzenie drogowe, w którym doszło do potrącenia osoby pieszej, autor zrelacjonował jego przebieg i proces rekonstrukcji, kładąc szczególny nacisk na kwestie związane z ustaleniem odległości dostrzeżenia przeszkody w warunkach nocnych. Ustalenie tej odległości na drodze oświetlonej latarniami ulicznymi w złych warunkach atmosferycznych wymaga wykonania eksperymentu. Autor zwrócił uwagę na potrzebę dołożenia wszelkich starań, aby uzyskać w czasie eksperymentu warunki drogowe jak najbardziej zbliżone do panujących w czasie wypadku oraz by uczestnicy eksperymentu nie wypatrywali przeszkody w miejscu, w którym znajduje się pozorant.

EN

The author describes an accident in which a pedestrian was hit and the process of its reconstruction with special focus on the issues of establishing the distance of sighting an obstacle at nighttime. To establish this distance on a road illuminated with a lamp post in poor atmospheric conditions it is necessary to perform an experiment. The author emphasizes the need for taking every effort to replicate the road conditions during the experiment closest possible to those during the accident. He also points to the necessity of taking care that the experiment participants do not watch for the obstacle in the place where the helper is located.

16

Measuring Equivalent Cohesion Ceq of the Frozen Soils by Compression Strength using Kriolab Equipment

Lemenkov Vasiliy, Lemenkova Polina

Civil and Environmental Engineering Reports

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2021

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Vol. 31, no. 2

63--84

EN

Current paper presents the results of the experimental analysis on permafrost uppermost soil samples with various physical properties (moisture, porosity) tested with varied external pressure and time. The aim of this work is to test properties of the soil samples intended for the construction of buildings, railways and objects of civil infrastructure by modeled external pressure, data visualization and analysis. Variations in the soil samples were studied by analysis of the equivalent soil cohesion (Ceq) in frozen soil samples. Methods include integrated application of the laboratory experiments, methods of the statistical data analysis and 3D plotting performed by the selected LaTeX packages. Laboratory experiments were performed using KrioLab equipment ‘Sharikovy Stamp PSH-1’. The 15 series of experiments have been tested. Models of the soil strength are graphically presented and statistically analyzed showing the results of the experiment.

17

Design and technological capabilities of a CNC skew rolling mill

Tomczak Janusz, Pater Zbigniew, Bulzak Tomasz, Lis Konrad, Kusiak Tomasz, Sumorek Andrzej, Buczaj Marcin

Archives of Civil and Mechanical Engineering

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2021

|

Vol. 21, no. 2

524--540

EN

Results of a study investigating a skew rolling process for elongated axisymmetric parts are presented. Despite the fact that the skew rolling technique for producing such parts was developed and implemented in the mid-twentieth century, there are no studies on this problem. The first part of this paper presents the results of FEM modelling of skew rolling stepped axles and shafts (solid and hollow). The FEM analysis was performed using the MSC Simufact Forming software. The numerical simulation involved the determination of metal flow patterns, the analysis of thermal parameters of the material during rolling, and the prediction of cracking by the Cockcroft-Latham ductile fracture criterion. Force parameters of rolling solid and hollow parts were also determined. The aim of the FEM analysis was to determine initial design assumptions and parameters for the development of the skew rolling mill. Later on in the paper, a design solution of a CNC skew rolling mill for rolling parts based on their envelope profile is proposed. FEM strength test results of a mill stand, obtained with MSC. NASTRAN, are presented. Finally, the performance test results of the constructed rolling mill are presented. The experiments involved rolling real stepped shafts that were modelled numerically. Obtained results show that the proposed skew rolling method has considerable potential. The designed and constructed rolling mill can be used to perform the rolling process according to the proposed method, with the tool and material kinematics being controlled based on the set parameters of a workpiece envelope.

18

Investigations on pool boiling of refrigerant R141b outside a horizontal tube

Baki Touhami, Aris Abdelkader, Tebbal Mohamed

Archive of Mechanical Engineering

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2021

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LXVIII, nr 1

77--92

EN

Boiling produces vapor with a phase change by absorbing a consistent amount of heat. Experimentation and modeling can help us better understand this phenomenon. The present study is focused on the heat transfer during the nucleate pool boiling of refrigerant R141b on the surface of a horizontal copper tube. The results of the experiment were compared with four correlations drawn from the literature, and the critical heat flux was examined for different pressures and also compared with the predicted values. Simulating boiling with two-phase models allowed us to infer the plot of the temperature distribution around the tube and compared it to results from other work.

19

Limit states of steel supporting structure for bridge cranes

Mantič Martin, Kuľka Jozef, Kopas Melichar, Faltinová Eva, Hrabovský Leopold

Zeszyty Naukowe. Transport / Politechnika Śląska

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2020

|

z. 108

141--158

EN

This paper describes a question of evaluation necessity of bridge cranes using the method of limit deformation state and oscillation damping. The solution was performed by means of theoretical analysis and an experimental verification at the selected bridge crane. The final result sounds that in the case of a correct strength computing of given bridge crane, it is not necessary to also check deformation and damping of oscillation as well.

20

Hydrogen - some historical highlights

Szydło Zbigniew A.

Chemistry-Didactics-Ecology-Metrology

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2020

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R. 25, NR 1-2

5--34

EN

The early history of experiments in which an inflammable air was prepared is outlined. Once hydrogen had been discovered by Cavendish in 1766, the world of science and technology was given a colossal impetus. Its scientific and social consequences form the main focus of this essay. Special attention is given to explain why experiments were done, and their aims. The many difficulties which confronted scientists in the interpretation of their results are discussed. Timelines have been used in order to facilitate an understanding of the evolution of ideas. A particular emphasis is given to the story of how, through spectral analysis of the hydrogen atom, our understanding of atomic structure developed. Experiments involving hydrogen constitute important teaching material in schools. Detailed instructions are given for making hydrogen in the laboratory and for demonstrating its lightness and flammability. Suggestions are made of how to use these reactions to teach a wide variety of chemical concepts and facts.