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Tytuł:
Thermal characterization of halloysite materials for porous ceramic preforms
Autorzy:
Kujawa, M.
Suwak, R.
Dobrzański, L.A.
Gerle, A.
Tomiczek, B.
Powiązania:
https://bibliotekanauki.pl/articles/2175810.pdf
Data publikacji:
2021
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
halloysite
DTA/TG
XRD
high-temperature microscope
linear changes
haloizyt
mikroskop wysokotemperaturowy
zmiany liniowe
Opis:
Purpose: The aim of the study was to investigate the possibility of sintering raw (natural) halloysite and pure halloysite to produce porous ceramic preforms, and determination of sintering temperature based on the results of investigations into thermal effects, linear changes and phase transitions. Design/methodology/approach: Due to mullitisation ability of halloysite at high temperature, alternative applications based on the sintering technology (including the production of reinforcement of metal matrix composites) are being searched for. Pure halloysite and Dunino halloysite were selected for the study. Findings: Pure halloysite, characterized by low impurities, dimensional stability during sintering, softening temperature above 1500ºC and ability to transform into mullite at temperatures above 950ºC could be used as a base for the production of sintered, porous mullite preforms. Research limitations/implications: Presence of impurities in Dunino halloysite, contribute to the shift of the sintering temperature towards lower temperatures and caused a rapid and uncontrolled shrinkage of the sample and the appearance of the softening temperature at 1300ºC. Practical implications: Based on the research of thermal (DTA/TG, linear changes in high-temperature microscopy) and XRD studies it is possible to determine the sintering temperature of pure halloysite to manufacture the porous mullite preforms with open porosity. Originality/value: The received results show the possibility of obtaining the new mullite preforms based on pure halloysite.
Źródło:
Archives of Materials Science and Engineering; 2021, 107, 1; 5--15
1897-2764
Pojawia się w:
Archives of Materials Science and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Contribution to knowledge of fungal biota of Kampinos National Park (Poland): part 3
Autorzy:
Gierczyk, B.
Szczepkowski, A.
Slusarczyk, T.
Kujawa, A.
Powiązania:
https://bibliotekanauki.pl/articles/2197178.pdf
Data publikacji:
2019-08-20
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
forest damage
fire damage
post-fire forest
macromycete
micromycete
Basidiomycota
Ascomycota
Kampinos National Park
Opis:
We present interesting findings from the final year (2018) of the project concerning fungi in the fire-damaged forests in Kampinos National Park (central Poland). Seven taxa have been collected which are new to the park, one species (Scutellinia patagonica) hitherto unrecorded in Poland has been found. The current number of macromycetes taxa known from Kampinos National Park has reached 1,611.
Źródło:
Acta Mycologica; 2019, 54, 2; 1129
0001-625X
2353-074X
Pojawia się w:
Acta Mycologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Contribution to knowledge of the mycobiota of Kampinos National Park (Poland): part 2
Autorzy:
Gierczyk, B.
Szczepkowski, A.
Ślusarczyk, T.
Kujawa, A.
Powiązania:
https://bibliotekanauki.pl/articles/2196349.pdf
Data publikacji:
2019-06-13
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
mycobiota
fire damage
pine forest
Ascomycota
Basidiomycota
Kampinos National Park
Polska
Opis:
Continuation of the mycological study of the fire-damaged pine forest in Kampinos National Park in central Poland in 2017 produced interesting new findings. Among the taxa collected, 36 were new to the park, six had not been hitherto reported from Poland (Calycellina araneocincta, Ciliolarina aff. laetifica, Clitocybe metachroides, Galerina cerina f. longicystis, Parasola cuniculorum, Pleonectria pinicola), and the previous status of one taxon (Pleonectria cucurbitula) had been uncertain. Short descriptions based on collected specimens have been prepared for all taxa new to Poland. The current number of taxa of macromycetes identified in Kampinos National Park has reached 1,604.
Źródło:
Acta Mycologica; 2019, 54, 1; 1116
0001-625X
2353-074X
Pojawia się w:
Acta Mycologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Macrofungi of the Bieszczady Mountains
Autorzy:
Gierczyk, B.
Kujawa, A.
Szczepkowski, A.
Ślusarczyk, T.
Pachlewski, T.
Chachuła, P.
Domian, G.
Powiązania:
https://bibliotekanauki.pl/articles/2197189.pdf
Data publikacji:
2019-12-05
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
macrofungi
macromycete
habitat richness
new taxon
description
Ascomycota
Basidiomycota
diversity
Bieszczady Mountains
Opis:
The Bieszczady Mts, a mountain range in SE Poland, is a hot spot of fungal richness and diversity in Poland. This paper summarizes 5 years of studies in the Bieszczady Mts, as well as previously published research. A total of 1,377 macromycetes taxa were found, including many (464) which were protected, red-listed, or very rare in Poland. Thirty-eight taxa (nine Ascomycota and 29 Basidiomycota) have been reported in Poland for the first time: Agrocybe gibberosa, Auriporia aurulenta, Bolbitius variicolor, Bulgariella pulla, Chaetosphaerella phaeostroma, Clitocybe subspadicea, Clitopilus passeckerianus, Cortinarius anomalus var. subcaligatus, C. fervidus, C. flexipes var. inolens, C. sylvae-norvegicae, Cudoniella tenuispora, Entoloma bisporigerum, E. olorinum, E. poliopus var. parvisporigerum, E. sericeoides, Galerina caulocystidiata, Gymnopilus josserandii, Hymenoscyphus subferrugineus, Hypholoma olivaceotinctum, Inocybe queletii, Laccaria altaica, Lactarius romagnesii, L. rostratus, Mycena epipterygia var. atroviscosa, M. epipterygia var. candida, M. polygramma f. candida, Octavianina lutea, O. mutabilis, Pachyella violaceonigra, Panaeolus papilionaceus var. capitatocystis, Phaeocollybia jennyae, Psathyrella almerensis, Pyrenopeziza inornata, Scutellinia torrentis, Tricholoma basirubens, Tricholomopsis flammula, and Vibrissea decolorans. For all new taxa, short descriptions based on the collected material have been provided.
Źródło:
Acta Mycologica; 2019, 54, 2; 1124
0001-625X
2353-074X
Pojawia się w:
Acta Mycologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pionowe zróżnicowanie bogactwa i składu gatunkowego myko-, licheno- i briobioty drzew powiatrołomowych w Kampinoskim Parku Narodowym
Vertical differentiation of the richness and species composition of the myco-, licheno- and briobiota of windthrown trees in Kampinos National Park
Autorzy:
Zaniewski, P.T.
Szczepkowski, A.
Gierczyk, B.
Kujawa, A.
Ślusarczyk, T.
Fojcik, B.
Powiązania:
https://bibliotekanauki.pl/articles/985753.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
parki narodowe
Kampinoski Park Narodowy
drzewa lesne
wiatrolomy
dab bezszypulkowy
Quercus petraea
Quercus x rosacea
brzoza brodawkowata
Betula pendula
sosna zwyczajna
Pinus sylvestris
epifity
epiksylity
grzyby makroskopijne
grzyby mikroskopijne
porosty
grzyby naporostowe
mszaki
bogactwo gatunkowe
sklad gatunkowy
zroznicowanie pionowe
biodiversity
quercus petraea
q. × rosacea
betula pendula
pinus sylvestris
rarefaction curve
Opis:
Vertical distribution of species richness of various groups of organisms within trees is still insufficiently understood. The reason for this are, among others, the difficulties in accessing standing trees. The aim of the study was to determine the differentiation of species richness of fungi, lichens and lichenicolous fungi and bryophyte of three tree species (oak, birch and pine) within windthrow areas in the Kampinos National Park (central Poland). Ten individuals of each tree species were chosen. They were only thrown, not broken, without serious damage, still alive and easily accessible. The investigations of species composition were performed in five parts of each tree: trunk bottom, lower trunk, upper trunk, lower crown and upper crown. Individual parts of the trees were measured, than their surface and volume were determined. The species richness of the studied groups of organisms was calculated using rarefaction curves based on the number of samples, volume and area of the distinguished tree parts. Species composition changes of the tree parts were described using non−metric multidimensional scaling. The most important parts of trees for fungi were the crowns of trees, in particular oak’s. The highest richness of lichens was found within the crown of oaks, however they were recorded within all of the distinguished tree parts. The highest richness of bryophytes was recorded in the lower crown of oak and the trunk base of birch, but this group of organisms generally did not inhabit the birch and pine crowns. In the case of rarefaction curves based on the number of samples, the large positive meaning of the oak was observed, however the observed pattern was different when the volume and surface were taken into account. The general species richness of the studied taxa was similar for three tree species, the pine was distinguished positively in case of fungi, birch – in the case of lichens and oak – in the case of bryophytes. The species of trees differ from each other in terms of the species composition of the studied groups of organisms. We also observed the gradual change in the species composition from the base of the trunk to the upper crown.
Źródło:
Sylwan; 2019, 163, 12; 980-988
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Students and emergency medicine: what is the standard level of first aid knowledge?
Autorzy:
Kujawa, K.
Żurek, G.
Serweta, A.
Stachowicz, A.
Gorączko, A.T.
Olejniczak, R.
Powiązania:
https://bibliotekanauki.pl/articles/2088352.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Opolski. Instytut Nauk o Zdrowiu
Tematy:
first aid
education
emergency medicine
universities
students
Opis:
Background: First aid is a critical skill, and knowing how to perform it may ultimately save a person’s life. Aim of the study: The aim of the study was to assess the level of first aid knowledge among students from three backgrounds: medicine, science, and the humanities. Material and methods: The authors surveyed a group of 180 fifth-year physiotherapy, geoinformatics, and psychology students, of which there were 60 from each discipline. The authors used an anonymous survey of their own design, composed of open- and closed-ended questions, which included 15 questions about first aid rules. The research was conducted in Wrocław, Poland. Results: Only 60 students (30.33%) had previously had the opportunity to receive first aid training during the course of their studies. An additional 100 students (55.56%) claimed they were familiar with first aid rules. Of the physiotherapy students, 32 (53.3%) declared they would remain calm and composed in an emergency situation, with men claiming they would remain more composed than women. The difference in behaviour turned out to be statistically significant; the value of the chi-square test was 13.74. Students who had had prior first aid training at university were the most familiar with life-saving techniques and claimed they would remain the most composed in an emergency situation (32 students from physiotherapy; 53:3%). Prior to taking the first aid exam, the majority of students (100 respondents; 55.6% of the total) were confident that they would obtain the maximum number of points possible on the test. However, upon completion, they were found to have a medium level of knowledge at 889 points out of 1,500, or 59%. Conclusions: The level of first aid knowledge among university students should be dramatically improved, so they are able to perform first aid with some level of expertise, should the need ever arise. To facilitate this, every university should include first aid classes in their curriculum. First aid techniques should be revised and refreshed every six months.
Źródło:
Medical Science Pulse; 2019, 13, 3; 16-21
2544-1558
2544-1620
Pojawia się w:
Medical Science Pulse
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ile gatunków grzybów rośnie w Puszczy Białowieskiej? Wystawy grzybów źródłem nowych danych
How many fungal species grow in the Bialowieza Forest? Exhibitions of fungi as a source of new data
Autorzy:
Kujawa, A.
Szczepkowski, A.
Gierczyk, B.
Ślusarczyk, T.
Powiązania:
https://bibliotekanauki.pl/articles/985939.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
Puszcza Bialowieska
mikologia
grzyby
Ascomycota
Basidiomycota
roznorodnosc gatunkowa
gatunki rzadkie
zrodla danych
wystawy przyrodnicze
ascomycota
basidiomycota
fungi
biodiversity
rare species
protected species
Opis:
Mycological data published in the years 2012−2017 in six papers on the exhibitions of fungi of the Białowieża Forest (NE Poland) was analysed to demonstrate that incidental, few days long field studies in that region may provide interesting and valuable data on fungal diversity and richness. The discussed papers, in addition to the lists of species presented, include information on some interesting taxa collected during the preparation of the exhibitions. This data complements the knowledge on the fungal biota of the Białowieża Forest and is documented by the herbarium specimens. There are 865 macrofungal taxa (72 of Ascomycota and 793 of Basidiomycota) mentioned in these papers. Almost half of them (421 taxa) were particularly valuable fungi, with 239 being new for the Białowieża Forest, i.e. they had not been reported from this area earlier. 75 taxa found during the field work preceding the exhibitions had not been found in Poland previously (e.g. Chromosera cyanophylla, Clitocybe collina, Cortinarius talimultiformis, Cystoderma subvinaceum). Moreover, 67 taxa have not been so far reported from other localities in Poland (e.g. Amylocystis lapponica, Pycnoporellus alboluteus and Steccherinum tenuispinum). 15 fungal species collected before the exhibitions are protected in Poland, 6 of them are strictly protected. 185 red−listed fungi were also found, among them 1 species with Ex (extinct) category (Scytinostroma galactinum) and 61 with E (endangered) category (e.g. Pholiota squarrosoides, Punctularia strigosozonata, Rigidoporus crocatus). An analysis of the published data indicates that even short−term, incidental studies may provide important and valuable data on the fungi of the Białowieża Forest and that the potential richness of its mycobiota is much higher than previously recognised and estimated. Presented results confirm the need for further basic research on the biodiversity of macrofungal biota of the Białowieża Forest. It should involve application of new research methods, participation of taxonomists specializing in specific fungal groups, identification of threats and establishing of a conservation program and population monitoring of the most valuable species in this area.
Źródło:
Sylwan; 2018, 162, 11; 933-940
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of shelf-transformed waters (STW) on foraminiferal assemblages in the outwash and glacial fjords of Adventfjorden and Hornsund, Svalbard
Autorzy:
Szymanska, N.
Pawlowska, J.
Kucharska, M.
Kujawa, A.
Lacka, M.
Zajaczkowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/48678.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Atlantic water
foraminiferal assemblage
glacial fjord
outwash fjord
Adventfjorden
Hornsund
Svalbard
inflow water
salinity
water temperature
environment change
Opis:
A new dataset of benthic foraminiferal assemblages from Adventfjorden (tributary fjord of Isfjorden, West Spitsbergen) was compared with the results of a study conducted by Zajączkowski et al. (2010) in Hornsund (West Spitsbergen). According to Nilsen et al. (2016), Atlantic water inflow to the Isfjorden Trough occurs more readily than to anywhere else along the shelf of Spitsbergen; thus, we compared the foraminiferal assemblages of the outwash Adventfjorden fjord, located in the Isfjorden system, with glacial Hornsund, located in southwest Spitsbergen. Despite the juxtaposition of Adventfjorden and Hornsund the data revealed varying impacts of shelf-transformed water (STW) on the benthic foraminiferal assemblages. Outer and central Adventfjorden was dominated by Adercotryma glomerata, Recurvoides turbinata and Spiroplectammina sp., reflecting the presence of STW, while abundant Melonis barleeanus in the central area of the fjord indicated a large flux of unaltered organic matter. Only the head of the fjord was dominated by the glaciomarine taxa Cassidulina reniforme and Elphidium clavatum. Foraminiferal fauna characteristic of STW-influenced environments (i.e., Nonionellina labradorica and R. turbinata) were also observed in outer Hornsund. However, the glacier-proximal taxa E. clavatum and C. reniforme were dominant throughout the fjord, demonstrating the impacts of meltwater and high sedimentation. Therefore, it is likely that in Hornsund, glacial impact is a major environmental factor, which is stronger than the influence of STW.
Źródło:
Oceanologia; 2017, 59, 4
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Manufacturing of Porous Ceramic Preforms Based on Halloysite Nanotubes (Hnts)
Autorzy:
Kujawa, M.
Dobrzański, L. A.
Matula, G.
Kremzer, M.
Tomiczek, B.
Powiązania:
https://bibliotekanauki.pl/articles/353563.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
metal matrix composites (MMC)
halloysite nanotubes
porous ceramic preforms
Opis:
The aim of this study was to determine the influence of manufacturing conditions on the structure and properties of porous halloysite preforms, which during pressure infiltration were soaked with a liquid alloy to obtain a metal matrix composite reinforced by ceramic, and also to find innovative possibilities for the application of mineral nanotubes obtained from halloysite. The method of manufacturing porous ceramic preforms (based on halloysite nanotubes) as semi-finished products that are applicable to modern infiltrated metal matrix composites was shown. The ceramic preforms were manufactured by sintering of halloysite nanotubes (HNT), Natural Nano Company (USA), with the addition of pores and canals forming agent in the form of carbon fibres (Sigrafil C10 M250 UNS SGL Group, the Carbon Company). The resulting porous ceramic skeletons, suggest innovative application capabilities mineral nanotubes obtained from halloysite.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 2B; 917-922
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Puszcza Białowieska - obiekt światowego dziedzictwa UNESCO - priorytety ochronne
The Bialowieza Forest – a UNESCO Natural Heritage Site – protection priorities
Autorzy:
Kujawa, A.
Orczewska, A.
Falkowski, M.
Blicharska, M.
Bohdan, A.
Buholz, L.
Chylarecki, P.
Gutowski, J.M.
Latałowa, M.
Mysłajek, R.W.
Nowak, S.
Walankiewicz, W.
Zalewska, A.
Powiązania:
https://bibliotekanauki.pl/articles/1294308.pdf
Data publikacji:
2016
Wydawca:
Instytut Badawczy Leśnictwa
Tematy:
lesnictwo
Puszcza Bialowieska
Swiatowe Dziedzictwo Kulturowe i Przyrodnicze UNESCO
wartosc przyrodnicza
las naturalny
ochrona przyrody
roznorodnosc gatunkowa
siedliska przyrodnicze
specjalne obszary ochrony siedlisk
natural forests
nature protection
biodiversity
natural ecological processes
forest management
Opis:
Despite the fact that only parts of the Białowieża Forest are protected as a national park and nature reserves, the forest is nevertheless as a whole considered a U NESCO Natural Heritage Site, Biosphere Reserve and an integrated Natura 2000 site. In the presently ongoing debate on the conservation priorities regarding the natural value of this forest and the current bark beetle outbreak, two distinct approaches can be recognized: (1) management assumed to involve considerable interference with the forest ecosystems; (2) maintenance of ecological processes and spontaneous restoration of the forest communities. The Białowieża Forest – especially its strictly protected parts – is a “bastion” where species characteristic of ancient forests (including so-called primeval forest relicts) have survived until today. This has been achieved by maintaining the forest’s complexity in areas with considerably reduced human influence, but most of all by maintaining a full spectrum of forest communities, naturally developing forests diverse in age, species composition and spatial structure including stand dieback and breakdown. The following factors need to be taken into account in the protection of the Natural Heritage Site: (1) the internationally recognized value of the Białowieża Forest including its biodiversity, the level of preservation of forest communities and the ongoing natural processes; (2) existing documents and policies concerning nature conservation; (3) research findings from the Białowieża Forest and other natural forest complexes. The key priority is to limit any activities in this forest to an indispensable minimum, mostly concerning security close to roads and tourist tracks as well as collection of fire wood by locals. Without this strict protection, successive and slow anthropogenic transformation will result in the Białowieża Forest sharing the same fate as other forest complexes of the temperate climate zone in Europe or America and lose its globally appreciated value.
Źródło:
Leśne Prace Badawcze; 2016, 77, 4
1732-9442
2082-8926
Pojawia się w:
Leśne Prace Badawcze
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of the ionizing radiation on the tribological properties of thermoplastic polymers rubbing against steel
Wpływ dawki promieniowania gamma na właściwości tribologiczne wybranych polimerów termoplastycznych współpracujących ze stalą
Autorzy:
Niemiec, A.
Kujawa, M.
Wieleba, W.
Powiązania:
https://bibliotekanauki.pl/articles/188965.pdf
Data publikacji:
2016
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
gamma irradiation
PEEK
PEI
PET
PA6
microhardness
friction coefficient
promieniowanie gamma
mikrotwardość
współczynnik tarcia
Opis:
The paper describes the effects of gamma radiation doses on the tribological and mechanical properties of selected thermoplastic polymers: PEEK, PEI, PET, and PA6. Samples of those polymers were irradiated with gamma rays of energy 1, 1.2, 3, 4, 5 MeV and with the intensity of the radiation beam 4, 7, 10, 30, 40 μA. With an increasing dose of radiation, properties such as microhardness, the friction coefficient of polymers, and the wear rate are changed. The chemical structure of the irradiated polymer may be changed by crosslinking but also by chain scission. The modified polymers may be used in medical science, electronics, and space technology. In this article, we report the results of steel C45 – thermoplastics (PEEK, PEI, PET, and PA6) friction couple during the slip motion. The analysis is focused on the friction coefficient, wear rate, and microhardness. Kinematic parameters of the experiment in slide movement were constant and defined by the following values: contact pressure p = 1MPa and sliding velocity v = 1m/s. The authors observed that, as gamma radiation dose increased, the microhardness and friction coefficient increased and their wear intensity decreased. Polymers change their microstructure and molecular structure when they are subjected to gamma ray irradiation, which results in modification on many important physical and chemical properties.
Celem niniejszej pracy było określenie wpływu dawki promieniowania gamma na właściwości tribologiczne i mechaniczne wybranych polimerów termoplastycznych: PEEK, PEI, PET, PA6. Wraz ze wzrostem dawki tego promieniowania właściwości takie jak microhardness, współczynnik tarcia statycznego oraz intensywność zużycia ulegają zmianie. Wymienione właściwości mogą być modyfikowane na skutek zachodzących zmian w strukturze chemicznej naświetlonych polimerów poprzez sieciowanie łańcuchów polimerowych, ale także ich rozerwanie. Zmodyfikowane polimery mogą być wykorzystane m.in. w medycynie, elektronice i technologii kosmicznej. W pracy opisano badania par ślizgowych stal C45 – wybrany polimer. Analizie poddano wartości współczynnika tarcia statycznego oraz intensywności zużycia materiału. Dla wszystkich analizowanych przypadków wartości parametrów ruchowych były stałe: siła nacisku wynosiła 1 MPa, a prędkość ślizgowa 1 m/s. Eksperyment wykazał zwiększenie wartości mikrotwardości i współczynnika tarcia oraz zmniejszenie intensywności zużycia.
Źródło:
Tribologia; 2016, 269, 5; 133-145
0208-7774
Pojawia się w:
Tribologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The influence of deformation of selected thermoplastics on the friction with steel
Wpływ odkształcenia wybranych polimerów termoplastycznych na tarcie po stali
Autorzy:
Kujawa, M
Niemiec, A.
Wieleba, W.
Powiązania:
https://bibliotekanauki.pl/articles/190650.pdf
Data publikacji:
2016
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
POM
PTFE
PE-HD
PMMA
deformation
change in the friction coefficient
change of hardness
odkształcenie
zmiana współczynnika tarcia
zmiana twardości
Opis:
Friction and wear of materials with additional deformation or stress is not a broadly described case. However, scientific publications considering this issue point out that additional deformation and stress ought to be taken into account during wear and friction analysis. In this article, the influence of strain in thermoplastics (POM, PTFE, PE-HD, PMMA) over the friction coefficient is described. Materials were deformed under tensile stress and examined after 24 hours. For specimens in which plastic strain was maintained, the decline of hardness (PE-HD: approximately 70% decrease, PTFE: approximately 40% decrease) and the reduction of the coefficient of kinetic friction (both PTFE and PE-HD: about 20% decrease) were observed. POM returned to its pre-deformed shape and PMMA was deformed without reaching its elastic limit. In these cases, only small changes in hardness (POM; approximately 10% decrease, PMMA: approximately 6% increase) and friction coefficients (maximum 4% change) occurred.
Tarcie i zużycie materiałów odkształconych lub naprężonych w wyniku działania sił niepochodzqcych od współpracy w skojarzeniu nie jest obszernie opisanym zagadnieniem. Jednakże publikacje traktujące o tej tematyce są zgodne w jednym: stan odkształcenia i naprężenia w materiale powinien być brany pod uwagę przy analizie zjawiska tarcia i zużycia. W artykule opisano wpływ odkształcenia polimerów termoplastycznych POM, PTFE, PE-HD i PMMA na współczynnik tarcia polimer-stal. Materiały rozciągnięto i pozostawiono w stanie nienaprężonym na 24 godziny. W próbkach, w których wystąpiło i utrzymało się trwałe odkształcenie plastyczne zaobserwowano zmniejszenie twardości (dla PE-HD o okolo 70%, dla PTFE o okolo 40%) i redukcji współczynnika tarcia kinetycznego (dla obu polimerów o ponad 20%). POM, który całkowicie powrócił do pierwotnej postaci i PMMA rozciągnięty tylko w zakresie sprężystym wykazały niewielkie zmiany odnośnie do twardości (POM spadek o okolo 10% i PMMA wzrost o okolo 6%) i współczynnika tarcia (zmiana o maksymalnie 4%).
Źródło:
Tribologia; 2016, 268, 4; 137-143
0208-7774
Pojawia się w:
Tribologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kampinoski Park Narodowy - ostoja różnorodności gatunkowej grzybów wielkoowocnikowych w Polsce
Kampinoski National Park - refuge of biodiversity of macromycetes in Poland
Autorzy:
Szczepkowski, A.
Kujawa, A.
Gierczyk, B.
Slusarczyk, T.
Powiązania:
https://bibliotekanauki.pl/articles/881117.pdf
Data publikacji:
2015
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Leśny Zakład Doświadczalny. Centrum Edukacji Przyrodniczo-Leśnej w Rogowie
Tematy:
grzyby
roznorodnosc gatunkowa
grzyby wielkoowocnikowe
grupy troficzno-substratowe
parki narodowe
Kampinoski Park Narodowy
Źródło:
Studia i Materiały Centrum Edukacji Przyrodniczo-Leśnej; 2015, 17, 3[44]
1509-1414
Pojawia się w:
Studia i Materiały Centrum Edukacji Przyrodniczo-Leśnej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preliminary studies of fungi in the Biebrza National Park. Part IV. Macromycetes - new data and the synthesis
Autorzy:
Kujawa, A.
Gierczyk, B.
Domian, G.
Wrzosek, M.
Stasinska, M.
Szkodzik, J.
Leski, T.
Karlinski, L.
Pietras, M.
Dynowska, M.
Henel, A.
Slusarczyk, D.
Kubiak, D.
Powiązania:
https://bibliotekanauki.pl/articles/67751.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
fungi
Biebrza National Park
macromycete
new data
macrofungi
rare species
protected area
protected fungi
threatened fungi
Opis:
The paper presents the last part of the results of the short-term inventory of fungi species in the Biebrza National Park and synthesises all the data gathered during two surveys, including the information published by other authors. The main body of research is focused on a survey of macrofungi identified with morphologybased methods. In case of some specimens molecular technics have been applied. In total 346 macrofungal taxa (21 belonging to ascomycetes and 325 to basidiomycetes) were found during the survey, including 186 species unobserved during the previous inventory in 2012. As a result of previous and ongoing studies, the current number of macrofungi recorded from the Biebrza National Park reached 508 species. Among them eight taxa are newly reported for Poland (Conocybe velutipes var. nitrophila, Entoloma caeruleum, E. plebejoides, Inocybe rennyi, I. vulpinella, Pholiota pityrodes, Pholiotina utricystidiata, and Tomentella pilosa). The next seven species (Bovista paludosa, Fistulina hepatica, Ganoderma lucidum, Geastrum schmidelii, Inonotus obliquus, Tulostoma kotlabae, and Xerocomus parasiticus) are protected by law and 95 species belong to red-listed species. The results of two intensive, but relatively short-term survey clearly indicate the Biebrza National Park as a hot spot of macrofungi and suggest the need to undertake extended and regular inventories also in other Polish national parks.
Źródło:
Acta Mycologica; 2015, 50, 2
0001-625X
2353-074X
Pojawia się w:
Acta Mycologica
Dostawca treści:
Biblioteka Nauki
Artykuł

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