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1
Content available The Effect of Cryogenic Cycling on the Mechanical Properties of Epoxy-Glass Composites
Krzak Anna, Nowak Agnieszka J., Gołombek Klaudiusz
Advances in Science and Technology. Research Journal
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2024
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Vol. 18, no 4
149--162
EN
Glass-epoxy laminates are characterized by exceptional properties such as high thermal insulation, resistance to mechanical damage, and stability at low temperatures. These crucial characteristics make them suitable for diverse applications, including cryogenics. Their application in cryogenics allows them to maintain low temperatures in research and industrial processes. This article ana-lyzes the effect of cryogenic cycles on the functional properties of composite materials. The study investigated the influence of cryogenic cycles on the mechanical properties of glass-epoxy laminates. Three sets of cycles were employed, each consisting of 1, 5, and 10 cycles. After each set of cycles, the mechanical properties, including impact strength, flexural strength, and Young's modulus, were measured and compared. Additionally, after each series, scanning electron microscopy (SEM) was used to carefully observe the material's surface and detect possible changes in its appearance and structure, such as cracks or deformations. Conclusions from the conducted research provide essential information on the correlation between cryogenic cycles and the functional properties of composites obtained by coating. The research results can be used to design and improve these materials in various industrial applications. This work determines the effect of a different composition of resin reinforced with glass fabric weighing 205 g/m2 on the mechanical properties of composite materials subjected to cryogenic cycles. This research aims to create innovative materials adapted to work in cryogenic environments.
2
Content available 140. rocznica skroplenia składników powietrza
Szytuła Andrzej
Postępy Fizyki
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2023
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T. 74, z. 2
35--36
PL
Artykuł ma na celu przypomnienie znaczenia skroplenia składników powietrza przez profesorów Karola Olszewskiego i Zygmunta Wróblewskiego w 140. rocznicę dokonania tego eksperymentu.
EN
The paper is a reminder of the importance of liquefaction of air components by professors Karol Olszewski and Zygmunt Wróblewski on the occasion of the 140th anniversary of this experiment.
3
Content available Mechanical analysis of multilayer composite materials with duroplastic matrix after exposure to low temperatures
Krzak Anna, Nowak A. J.
Archives of Materials Science and Engineering
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2023
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Vol. 122, nr 2
49--57
EN
Purpose: Cryogenic engineering is gaining more and more interest in various industry sectors, which leads to an intensive search for effective solutions. The article presents the findings of mechanical testing conducted on glass-epoxy laminates at room temperature and after long- term contact with liquid nitrogen. Design/methodology/approach: To compare the impact properties and flexural strength, the samples were tested under cryogenic and room conditions, and then the fracture locations were identified using the Leica DVM6 microscope. The study brings value to the emerging field of cryogenic engineering by providing valuable information on the mechanical properties of glass-epoxy composites under cryogenic conditions. Findings: It has been found out that immersing the glass-epoxy composites into the Dewar had minimal influence on impact and flexural strength properties. The most noticeable changes were observed in the case of the EP_4_2 composite. The material consists of a solution of brominated epoxy resin in an organic solvent. It is used to produce laminates in electrical engineering and printed circuits in electronics, where it should exhibit excellent impact properties. Research limitations/implications: One of the prospective research directions is a thorough analysis of the mechanical properties of the developed composite materials during cryogenic cycles. Originality/value: The study aims to determine the effect of different compositions of glass fabric-reinforced resin with a weight of 205 g/m2 on the mechanical properties of the developed composite materials at both room temperature and after long-term exposure to liquid nitrogen. Those investigations serve as surveillance for developing of new material solutions directed towards cryogenic applications and are essential for subsequent stages of research.
4
Content available Design and validation of a single-jack variable Mach number nozzle in a cryogenic transonic wind tunnel
Yu Chengguo, Zhang Zhili, Wang Ning, Nie Xutao, Peng Qiang, Chen Zhenhua
Journal of Theoretical and Applied Mechanics
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2022
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Vol. 60 nr 4
719--732
EN
The wind tunnel with variable Mach numbers controlled by a single jack is highly desired in the aerospace, automobile and building industry due to its superior controllability and working range. Decreasing the temperature of a test gas is an efficient and economical approach to achieving higher Reynolds numbers that accommodate all working statuses of test subjects, which however, brings new challenges to the wind tunnel design nowadays. This paper proposes a new design concept of a single-jack variable Mach number nozzle based on its particular cryogenic characteristics, as the nozzle is the core structure to achieve variable Mach numbers. The contours of the nozzle under different Reynolds numbers and Mach numbers are modeled and solved by an incomplete elliptic integral, followed by modification with cryogenic characteristics. A 0.3-m cryogenic wind tunnel is utilized as a validation platform for the nozzle design, resulting in designed contours being in line with the measured contours. Moreover, the root means square (RMS) deviations of Mach number 1.3 at the core position are controlled within 0.011 in low and high temperatures, which surpasses the other existing wind tunnels.
5
Content available Experimental investigation of cryogenically treated HSS tool in turning on AISI1045 using fuzzy logic – Taguchi approach
Raja P., Malayalamurthi R., Sakthivel M.
Bulletin of the Polish Academy of Sciences. Technical Sciences
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2019
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Vol. 67, nr 4
687--696
EN
This work depicts the effects of deep cryogenically treated high-speed steel on machining. In recent research, cryogenic treatment has been acknowledged for improving the life or performance of tool materials. Hence, tool materials such as the molybdenum-based high-speed tool steel are frequently used in the industry at present. Therefore, it is necessary to observe the tool performance in machining; the present research used medium carbon steel (AISI 1045) under dry turning based on the L9 orthogonal array. The effect of untreated and deep cryogenically treated tools on the turning of medium carbon steel is analyzed using the multi-input-multi-output fuzzy inference system with the Taguchi approach. The cutting speed, feed rate and depth of cut were the selected process parameters with an effect on surface roughness and the cutting tool edge temperature was also observed. The results reveal that surface roughness decreases and cutting tool edge temperature increases on increasing the cutting speed. This is followed by the feed rate and depth of cut. The deep cryogenically treated tool caused a reduction in surface roughness of about 11% while the cutting tool edge temperature reduction was about 23.76% higher than for an untreated tool. It was thus proved that the deep cryogenically treated tool achieved better performance on selected levels of the turning parameters.
6
Content available remote Praca przetwornika optoelektronicznego TSL250R w niskiej temperaturze
Pająkowski J.
Przegląd Elektrotechniczny
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2015
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R. 91, nr 12
284-287
PL
W pracy przedstawiono wyniki badań zachowania czujnika optoelektronicznego TSL250R, który jest fotodiodą zintegrowaną z wewnętrznym wzmacniaczem operacyjnym. Przedstawiono charakterystyki przejściowe czujnika w funkcji temperatury. Zakres temperatury wynosił 77-300 K. Wyniki porównano z innymi czujnikami światła przebadanymi w niskich temperaturach.
EN
In the paper the results of tests of behavior of a light-to-voltage optical sensor TSL250R, which is a photodiode integrated with an external operational amplifier are presented. There are also included transient characteristics of the sensor in function of temperature. The temperature ranged from 77 K to 300 K. The results were compared with other light sensors tested at low temperature.
7
Content available remote Modeling of heat flow through multilayer internal supports of cryogenic vessels
Czyżycki W.
Czasopismo Techniczne. Mechanika
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2015
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Y. 112, iss. 2-M
27--34
EN
The article presents the issue of heat flow through internal supports of double-walled cryogenic vessels. The influence of the thermal resistance at the contact plane between supports and vessel materials is discussed. A simulation of heat flow through the support multilayer made of plastic is presented. The simulation takes into account the influence of temperature and local contact pressure on the thermal resistance.
PL
W artykule przedstawiono zagadnienie przepływu ciepła przez wewnętrzne podpory dwupłaszczowych zbiorników kriogenicznych. Omówiono wpływ oporu cieplnego w miejscu styku materiałów podpór i zbiornika. Przedstawiono symulację przepływu ciepła przez podpory wielowarstwowe wykonane z tworzyw sztucznych. W symulacji uwzględniono wpływ temperatury i lokalnej wartości nacisku powierzchniowego na opór cieplny.
8
Termodynamiczny model przemian fazowych podczas międzykrytycznego azotowania austenitycznego
Wei Y., Żurecki Z., Sisson R.D.
Inżynieria Powierzchni
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2013
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nr 2
56--62
PL
Artykuł opisuje wyniki pracy eksperymentalnej na stali AISI4140 (odpowiednik stali 42CrMo4) i badań wzajemnego oddziaływania azotowania i warunków chłodzenia oraz transformacje faz w obu typach azotowania: ferrytycznym (525°C) i międzykrytycznym austenitycznym (610°C). Termodynamiczny model użyty do wstępnego projektowania warunków procesu został również zastosowany do oceny mikrostruktury azotowanej warstwy. Badania struktur przeprowadzono za pomocą metod SEM, EPMA i EDS. W artykule przedstawiono także kinetykę wzrostu stref dyfuzyjnych oraz kontrolę wymiarową azotowanych części w wyniku zmian fazowych.
EN
This paper presents results of experimental work on AISI4140 steels, examining the interplay between the nitriding and cooling conditions and phase transformations in both ferritic (525oC) and subcritical, nitrogen-austenitic (610oC) processes. Thermodynamic model, used to design process conditions, is applied also in the microstructural interpretation of nitrided layers, examined via SEM, EPMA and EDS. Kinetics of interstitial diffusion and phase transformation-based dimensional control of nitrided parts are also presented.
9
Otwarty kriostart azotowy
Pająkowski J.
Elektronika : konstrukcje, technologie, zastosowania
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2004
|
Vol. 45, nr 5
33-34
PL
Opisany w artykule kriostat azotowy służy do pomiaru charakterystyk temperaturowych parametrów elektrycznych i optycznych elementów półprzewodnikowych w zakresie temperatury od 77 K do temperatury otoczenia.
EN
The nitrogen cryostat described in the article is used for measuring electrical and optical parameters of semiconductor elements in the temperature ranging from 77 K to the temperature of environment.
10
Content available remote Materiałoznawcze problemy eksploatacji urządzeń technicznych w niskich temperaturach
Wojtkun F.
Problemy Eksploatacji
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2001
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nr 4
337-344
PL
Przedstawiono specyfikę eksploatacji maszyn, urządzeń i konstrukcji w warunkach niskich temperatur klimatycznych oraz w kriogenice aerokosmicznej, nadprzewodnikowej i in. Na tym tle zestawiono kompleks wymagań technologicznych, materiałowych i eksploatacyjnych. Omówiono podstawowe grupy materiałów stosowanych w eksploatacji nisko-temperaturowej, istotę konstruowania ich struktury oraz prognozy badawczo-rozwojowe.
EN
The specific of machine, installation and construction's exploitation in low temperature condition and in cryogenic of aerocosmic, superconductivity etc. has been presented. In a such context technological, material and exploitation requirements has been composed. The basic group of material used in low temperature exploitation and the essence of their structure construction, as well as a research foresight have been discussion.
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