Wyniki wyszukiwania - Biblioteka Nauki

1

Adhezja metali i tarcie ślizgowe

100%

Kusiak C.

Tribologia

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2007

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tom nr 2

391-398

PL

W pierwszej części artykułu omówiono zjawisko adhezji, jej wpływ na współczynnik tarcia oraz problemy i trudności pomiaru siły adhezji w procesach tarcia ślizgowego. Przedstawiono nową zasadę eksperymentalnego wyznaczania zarówno siły (współczynnika) tarcia oraz siły adhezji, przydatną szczególnie w badaniach tribologicznych. Zasada ta polega na wykonywaniu obydwu tych pomiarów podczas jednego, tego samego połączenia próbek. Omówiono budowę i działanie urządzenia do tych pomiarów oraz przedstawiono przykładowe wyniki badań. W drugiej części artykułu przedstawiono wyniki badań tarcia i adhezji próbek stalowych z warstwą oleju na powierzchni. Otrzymane rezultaty obrazują jakościowe oraz liczbowe związki między siłą tarcia i siłą adhezji.

EN

In the first part of this paper, a phenomenon of adhesion and its influence on the coefficient of friction together with problems and difficulties in the measurement of adhesion forces in the process of sliding friction were discussed. A new method of experimental determination of both the force of friction (the coefficient of friction) and the force of adhesion was presented. The method, which is especially useful in tribological investigations, consists in a simultaneous measurement of the two values of forces in a one coupling of specimens. The design and operations rule of an apparatus for these measurements was discussed. Exemplary results of testing were also included. In the second part of the paper, the results of investigations of friction and adhesion in steel specimens were presented. The testing was carried out in agreement with the presented method for the following operational conditions: with a layer of liquid on the surface and on a dry surface. The results obtained illustrate, in a quantitative and qualitative way, a mutual relation between forces of friction and adhesion.

2

Wyznaczenie składowej adhezyjnej współczynnika tarcia pary stal-elastomer

100%

Gawliński M. , Rogula J.

Tribologia

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2002

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tom nr 3

835-842

PL

W pracy rozważono sposób określenia składowej adhezyjnej współczynnika tarcia pary guma-stal. Dla takiej pary wartość współczynnika tarcia zależy głównie od składowej adhezyjnej. Wartość składowej adhezyjnej współczynnika tarcia wyznaczono na tribometrze jednokulowym własnej konstrukcji. Wyznaczenie tej wartości pozwala na określenie przydatności danej mieszanki gumowej na uszczelnienia już na etapie przygotowania próbek. Dla badanych materiałów elastomerowych wyznaczono wartości stałych materiałowych tau(0) i beta, które pozwolą na określenie wartości współczynnika tarcia przy założeniu dowolnego nacisku. Badania przeprowadzono dla trzech materiałów: guma NBR (nitrylowa) - o twardości wg stopni Shore'a 60 i 80, guma ACM (akrylowa) - o twardość wg stopni Shore'a 62 i 75, guma FPM (fluorowa) - twardość wg stopni Shore'a 65 i 70. Przeprowadzone badania pozwoliły określić wpływ twardości danej mieszanki gumowej na wartość składowej adhezyjnej współczynnika tarcia. Badania prowadzono przy tej samej wilgotności i temperaturze w jakiej prowadzone są badania ścieralności gumy zgodnie z PN.

EN

This paper presents the method of determination of adhesion component of friction coefficient of the rubber- metal pair. For such joints the friction coefficient value depends mainly on the adhesion component. The values of the adhesion component of friction coefficient were determined by means of one-ball tribometer for different rubber grades used in production of the oil lip seals. Determination of this value makes easy an estimation of the rubber quality just on the stage of the formulation. Material constants tau(o) and beta were calculated from experimental data for all examined rubbers; the knowledge of these constants enables prediction of the friction coefficients at given load. The tests were carried-out for three rubber types: NBR with hardness of 60 and 80 IHRD, ACM with hardness of 62 and 75 IHRD and FPM - 65 and 70 IHRD. It was also possible to find dependance of adhesion component of friction on the elastomer hardness. The test were run at the same humidity and temperature as the tests concerning rubber wear resistance according with Polish Standard.

3

Adhesion properties of human bladder cell lines with extracellular matrix components: the role of integrins and glycosylation.

100%

Lityńska A. , Przybyło M. , Pocheć E. , Laidler P.

Acta Biochimica Polonica

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2002

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tom 49

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nr 3

643-650

EN

Integrin subunits present on human bladder cells displayed heterogeneous functional specificity in adhesion to extracellular matrix proteins (ECM). The non-malignant cell line (HCV29) showed significantly higher adhesion efficiency to collagen IV, laminin (LN) and fibronectin (FN) than cancer (T24, Hu456) and v-raf transfected (BC3726) cell lines. Specific antibodies to the α2, a5 and β1 integrin subunits inhibited adhesion of the non-malignant cells, indicating these integrin participation in the adhesion to ECM proteins. In contrast, adhesion of cancer cells was not inhibited by specific antibodies to the β1 integrin subunit. Antibodies to α3 integrin increased adhesion of cancer cells to collagen, LN and FN, but also of the HCV29 line with colagen. It seems that α3 subunit plays a major role in modulation of other integrin receptors especially in cancer cells. Differences in adhesion to ECM proteins between the non-malignant and cancer cell lines in response to Gal and Fuc were not evident, except for the v-raf transfected cell line which showed a distinct about 6-fold increased adhesion to LN on addition of both saccharides. N-Acetylneuraminic acid inhibited adhesion of all cell lines to LN and FN irrespective of their malignancy.

4

Experimental Determination of Limit Adhesive Shear Stress between Solid Wall and Liquid

100%

Sawicki J. M.

Archives of Hydro-Engineering and Environmental Mechanics

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2014

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tom Vol. 61, nr 3-4

175–-181

EN

The slip boundary condition can be a very useful relation when some specific problems of hydromechanics are considered. According to the classical form of this condition, the slip of a fluid with respect to the solid wall should occur even at a very low velocity of motion. However, both theoretical analysis and certain empirical data suggest that there must be a limit value of the wall shear stress, below which the slip does not occur. According to the simplified balance of adhesive and gravitational forces, a simple experimental method for determining this stress has been proposed and applied in this paper.

5

Niektóre właściwości dwuwarstwowej powłoki ZrO₂+5%CaO - Ni-Al natryskanej plazmowo

100%

Woźniak A. , Przetakiewicz W.

Biuletyn Wojskowej Akademii Technicznej

|

1999

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tom Vol. 48, nr 12

151-160

PL

Przedstawiono ocenę przydatności natryskanej plazmowo dwuwarstwowej powłoki ZrO₂+5% CaO - Ni-Al 70/30 na podłoże ze stopu AK20. Przeprowadzono badania strukturalne i pomiary przyczepności. Wskazano na konieczność stosowania międzywarstwy Ni-Al dla uzyskania odpowiedniej przyczepności do podłoża.

EN

The purpose of this work was to examine some properties of the ZrO₂+5%CaO duplex coating system, such as adhesion to the base AK20. It was shown, that application of Ni-Al interlayer contributes to increasing adhesion of ceramic coating to aluminium base.

6

Friction forces and friction coefficient in slide parabolic micro-bearing with consideration of the adhesion force

100%

Miszczyk M. A. , Czaban A.

Journal of KONES

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2010

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tom Vol. 17, No. 3

293-299

EN

Micro-bearings have many applications in computer devices, such as CPU fans or hard disc drives. So far, rolling bearings and slide bearings have been used,for example micro-bearing with smooth Journal and sleeve surface, which is known as FDB - Fluid Dynamic Bearing. Actually, latter versions of micro-bearings are being launched to the market: Ex-FDB - Extra Fluid Dynamic Bearing. This type of bearings was fabricated by putting some micro-grooves filled with oil on its interna! surfaces. Ex-FDB's are characterized by reduced level of generated noise and guarantee long failure-free fan life, reaching 120 000 hours. In this paper we present our numerical calculations of the friction force and the friction coefficient in the parabolic micro-bearing. Micro-bearing gap height is very low, often less then l micrometer, therefore capillarity and adhesion forces cause an increase of oil viscosity near the Journal and sleeve surfaces. Due to this fact a value of hydrodynamic pressure in micro-bearing gap also increases, what results in observed changes of capacity, friction forces and friction coefficient values. The influence of adhesion and capillarity on friction force and friction coefficient of oil in micro-bearing hasn't been considered from analytical point of view so far. This paper presents numerical results of computed values of friction forces and friction coefficient for parabolic micro-bearing in comparison to values for classical parabolic bearing.

7

Oxide coatings on titanium produced by oxidation in fluidized bed

100%

Jasiński J. , Mendzik K. , Tatar K. , Szota M.

Advances in Materials Science

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2008

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tom Vol. 8, nr 1(15)

48-53

EN

The main product of a process of titanium oxidation is titanium oxide, which covers the titanium surface. More-over oxidation in fluidized bed in temperature range of 600-700°C influences on outer layers of titanium specimen, where a diffusion layer of oxygen is observed. Microstructures of titanium with visible oxide coatings on its surface after thermo-chemical treatment are described. Microhardness measurements of titanium surface layers after oxidation process were made with a Knoop microhardness tester and showed significant differences accord-ing to oxidation parameters. Finally, the surfaces of titanium after oxidation in fluidized bed were scratched in aim to measure their adhesion to the substrate surface.

8

Material Factors in Relation to Development Time in Liquid-Penetrant Inspection. Part 2. Investigation Programme and Preliminary Tests

100%

Irek P. , Słania J.

Archives of Metallurgy and Materials

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2016

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tom Vol. 61, iss. 3

1697--1708

EN

The paper is the continuation of the previous one entitled “Material factors in relation to development time in liquid-penetrant inspection. Part 1. Material factors” in which the material factors influencing essentially the development time in penetrant testing have been marked out. These are: type of material, surface roughness and imperfection width. In the paper it has been described how to prepare the factorial plan which will enable to test every factor with taking into account its different values. Moreover, it has been presented investigations on natural cracks, their width and roughness profile what will allow to assign suitable values of independent variables to the factorial plan. The purpose of the plan prepared in such a way will be the determination of the influence of the material kind, surface roughness and discontinuity width on the development time in penetrant testing.

9

SpaCBA sequence instability and its relationship to the adhesion efficiency of Lactobacillus casei group isolates to Caco-2 cells

100%

Markowicz C. , Olejnik-Schmidt A. , Borkowska M. , Schmidt M.

Acta Biochimica Polonica

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2014

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tom 61

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nr 2

341-347

EN

The ability to adhere to enterocytes is one of the key features of probiotics. This process involves a number of factors, among which the important role of pili was demonstrated. Some Lactobacillus species are confirmed to have heterotrimeric spaCBA type pili. The aim of this study was to identify spaCBA pili in strains of selected Lactobacillus spp. and assess the impact of their presence and sequence polymorphism on the adhesion of these strains to enterocytes. Total 20 bacterial strains of L. rhamnosus, L. casei and L. paracasei were tested. The presence of pilus specific proteins coding genes spaA, spaB and spaC was verified by PCR in order to identify the presence of sequence polymorphism in the genes possibly affecting the structure of the spaCBA pilus. To correlate spaCBA polymorphism to adhesion capability the adhesion assay was carried out using Caco-2 cell line. The effectiveness of the adhesion was measured using a scintillation counter. The Lactobacillus strains analyzed showed the adhesion to Caco-2 enterocytes capability from 0.6% to 19.6%. The presence of spaCBA pili is a factor increasing the adhesion efficiency of Lactobacillus spp. to Caco-2 enterocytes. Lack of these structures on the surface of bacterial cells results in the reduction in adhesion efficiency, indicating its important role in the adhesion process. But not in all cases the correlation between the presence of protein spaCBA structures and adhesion efficiency was observed, what may indicate the important role of other factors in adhesion of analyzed strains to Caco-2 cells.

10

Degradation of coatings based on 310S steel doped with Al and Ir additives by the scratch test

100%

Kucharska B.

Open Physics

|

2011

|

tom 9

|

nr 4

1122-1130

EN

Mechanical tests of PVD coatings made on steel 310S were carried out within this study by the scratch test method. It was found that the additions of Al and Ir caused lower critical load values compared to the coating without additions. Despite the reduction of the critical load of the coating by the aluminium addition, the effect of aluminium was considered advantageous owing to the refinement of the structure causing the coating to become more plastic and reducing the number and sizes of micro-cracks. The addition of iridium results in an embrittlement of the coating structure and its poorer adhesion to the substrate. Comparison of the findings from the scratch test with the observations from an optical and a scanning microscopes was also made.

11

Adhesion and capilarity in micro-bearing lubrication

100%

Wierzcholski K. , Miszczak A.

Journal of KONES

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2009

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tom Vol. 16, No. 3

489-495

EN

Present paper shows the some main phenomena which have important influence on the micro-bearing operating parameters. To above mentioned phenomena belong: adhesion forces, adsorption forces, capillary forces, elastic and hyperelastic deformations of cooperating micro-bearing surfaces, Van-der Waals electrostatic forces on the micro-bearing surfaces. Because the height of super thin micro-bearing gap is very small often smaller than l micrometer, hence the adhesion forces and capillary forces arising in micro-bearing gap, provoke the oil dynamic viscosity changes. This fact leads to the hydrodynamic pressure and bearing carrying capacity changes. The performed research play off the main role of mechanical micro-deformations of cooperating micro-bearing surfaces on non-Newtonian oil dynamic viscosity and here are indicated the influence of capillary force on adhesion forces in micro-scale. The micro-deformations of the micro-bearing gap height are effecting the changes of oil flow velocity in the gap, this fact leads to the share rate changes and therefore we obtain changes of apparent viscosity of the non-Newtonian oil.

12

Contact problems with friction, adhesion and wear in orthopaedic biomechanics. Part I - general developments

100%

Rojek J. , Telega J. J.

Journal of Theoretical and Applied Mechanics

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2001

|

tom Vol. 39 nr 3

655-677

EN

The present paper is a continuation of the contribution by Rojek and Telega (1999). An alternative adhesion law is used to the study of the bone-implant interface. Various problems related to the bone-implant interface are discussed.

PL

Zagadnienia kontaktowe z tarciem, adhezją i zużyciem w biomachanice ortopedycznej. Część I - Rozważania ogólne. Niniejsza praca stanowi kontynuację wcześniejszej pracy autorów, por. Rojek i Telega (1999). Zastosowano alternatywny model adhezji dla opisu interfazy kość-implant. Przedyskutowano równierz szereg zagadnień związanych z tą interfazą.

13

Thermal degradation of solvent-borne water soluble acrylic acid-butyl acrylate copolymers

100%

Czech Z. , Pełech R.

Materials Science Poland

|

2009

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tom Vol. 27, No. 3

851--856

EN

Thermal degradation of water soluble copolymers synthesized from acrylic acid and butyl acrylate, used as water soluble self-adhesives, especially for bonding of different kinds of paper, was investigated at 250 °C using pyrolysis-gas chromatography. The thermal degradation process and the kind and amounts of the pyrolysis products provide relevant information about the thermal resistance of water soluble acrylic adhesives. It was observed that during the pyrolysis of acrylic acid-butyl acrylate copolymers main breakdown products as carbon dioxide, butene-1, butanol-1, butyl acrylate and butyl methacrylate were formed.

14

Bacterial adhesion to implantable materials

100%

Harris L. G. , Richards R. G.

Inżynieria Biomateriałów

|

2004

|

tom R. 7, nr 37

4-5

15

Material Factors in Relation to Development Time in Liquid-Penetrant Inspection. Part 1. Material Factors

100%

Irek P. , Słania J.

Archives of Metallurgy and Materials

|

2016

|

tom Vol. 61, iss. 2A

509--514

EN

In technical publications and European Standards the development time (i.e. time of getting out of penetrant from a discontinuity to the material surface) in penetration testing is specified within the range of 10-30 minutes. In practice, however, it is seen , that it is closely connected with the material type and ranges from several minutes to 24 hours. In the literature, only interactions coming from the penetrant are described, whereas those from the material under testing, i.e. the influence of material factors on adhesion between penetrant and material, are not taken into consideration. In this connection, it has been described precisely in the paper the adhesion phenomenon and also it has been indicated the other factors affecting the development time. Recapitulating the adhesion theories presented in the paper, it can be formulated two fundamental circumstances which must occur that adhesion joint may be formed, namely: the approach of the particles of two solids to the distance less than 0,9 nm while the high attractive force occurring between molecules should be connected with possibly low potential energy of the bond formed in this way.

16

Monitoring of the kinetics of adhesive bond type car putty coating-steel substrate with ultrasonic method

100%

Ulbrich D. , Jósko M. , Mańczak R.

Journal of Research and Applications in Agricultural Engineering

|

2013

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tom Vol. 58, nr 1

189--192

PL

W artykule przedstawiono metodę monitorowania konstytuowania połączenia adhezyjnego typu powłoka szpachlówkowapodłoże stalowe. Badania wykonano na próbkach stalowych. Celem badań było wyznaczenie, na podstawie zmiany wysokości impulsu ultradźwiękowego, trendu zmiany wzmocnienia sygnału i modułu ciśnieniowego współczynnika odbicia. Wyniki zobrazowano na wykresach; przedstawiono wartości maksymalne, minimalne i średnią wyżej wymienionych parametrów w czasie utwardzania połączenia, który wynosił 60 minut, a zmiany wysokości pierwszego echa sygnału ultradźwiękowego zapisywano co 3 sekundy. W kolejnym etapie badań zostanie zastosowana inna powłoka szpachlówkowa, a otrzymane wyniki będą porównane z zaprezentowanymi w niniejszym artykule.

EN

A method used for monitoring the formation process of adhesive bond type car putty coating and steel substrate is presented in this article. In the experiment some samples made of steel and universal car putty are used. The main goal of the experiment is to designate changes of two parameters: the variation of the ultrasonic gain and reflection coefficienvt during the cure time. These parameters are calculated based on the echo height changes of the ultrasonic signal. The test’s results: average, minimum and maximum values of determined parameters are shown in the figures. Time of the test is equal to 60 minutes and every three seconds the variation of echo height is recorded. The obtained results will be compared to the results for other car putties as the next step of the research.

17

The chaperone-usher pathway of bacterial adhesin biogenesis - from molecular mechanism to strategies of anti-bacterial prevention and modern vaccine design*

100%

Piątek R. , Zalewska B. , Bury K. , Kur J.

Acta Biochimica Polonica

|

2005

|

tom 52

|

nr 3

639-646

EN

The chaperone-usher system determines the biogenesis of surface-exposed adhesive structures responsible for virulence of many Gram-negative bacteria. Investigations of the last 20 years have resolved the mechanism of this pathway on a structural level for different species of pathogenic bacteria. The purpose of this review is to present the molecular mechanisms of the biogenesis of adhesive structures assembled via the chaperone-usher pathway. The obtained mechanistic data allow one to propose potential strategies of anti-bacterial action. Additionally, the specific properties of the polymeric adhesive structures (pili and fimbriae) of the chaperone-usher system allow their use as effective and safe recombinant vaccines carrying foreign epitopes in thousands of copies on bacterial cell surface.

18

Badanie wpływu chropowatości podłoża stalowego i działania polem ultradźwięków na przyczepność ochronnej powłoki polimerowej

100%

Piaseczny L. , Walkowski M.

Czasopismo Techniczne. Mechanika

|

2004

|

tom R. 101, z. 7-M/2

441--450

PL

Przedstawiono wyniki badań przyczepności powłok z kompozycji polimerowych do podłoża stalowego. Wykazano, że przyrost chropowatości podłoża stalowego i pole ultradźwięków wpływają na przyczepność powłoki polimerowej.

EN

The results of the adhesion strength test of polymer coating on the steel base were presented. It was found that increase of the steel base roughness and ultrasound field influenced on the adhesion strength of polymer coating.

19

Problemy badania adhezji w warunkach laboratoryjnych

100%

Poncyliusz M. M.

Przegląd Mechaniczny

|

2011

|

tom nr 12

22-28

20

Material factors in relation to development time in liquid-penetrant inspection. Part 3. Testing of model plates

100%

Irek P. , Słania J.

Archives of Metallurgy and Materials

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2017

|

tom Vol. 62, iss. 1

41--49

EN

The paper is the continuation of the previous ones entitled „Material factors in relation to development time in liquid-penetrant inspection. Part 1. Material factors“ and „Material factors in relation to development time in liquid-penetrant inspection. Part 2. Investigation programme and preliminary tests“ in which material factors influencing essentially the development time in penetrant testing as well as the range of their values have been specified. These factors are: material kind, surface roughness and imperfection width. In the paper it has been described how far the development time in colour penetrant testing is influenced by an individual material factor. Moreover, it has been presented the equation being the function of material factors and development time.