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Tytuł:
Genetic variability and host specialization in Alternaria alternata colonizing Solanaceous crops in Sudan
Autorzy:
Abbo, A.S.
Idris, M.O.
Elballa, M.A.
Hammad, A.M.
El Sidding, M.A.R.
Karlovsky, P.
Powiązania:
https://bibliotekanauki.pl/articles/66044.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
plant disease
early blight
genetic variability
host
Alternaria alternata
diversity
Solanaceae
crop
amplified fragment length polymorphism
Sudan
Opis:
Early blight disease caused by Alternaria sp. is one of the most devastating diseases of Solanaceous crops widely distributed in Sudan. The aim of this study was to determine the genetic variation among different Alternaria isolates recovered from different Solanaceae crops showing typical symptoms of early blight disease. Infected leaves of tomato, potato, eggplant and pepper were collected from different geographical zones in Sudan. The recovered fungal isolates were identified to the genus level based on cultural and morphological characteristics. Five representative isolates were sent to the CABI Bioscience, U.K. for confirmation. The genetic relationship among the isolates was determined using the amplified fragments length polymorphism (AFLP) technique and the generated data were used to create similarity matrices using the PAST 3.01 software package. Dendrograms were constructed based on Jaccard’s similarity coefficients. A total of 70 fungal isolates was recovered from the tested plants and all of them showed morphological characteristics typical of Alternaria spp. The conidia appeared in multiple-branched chains with spore sizes in the range of 2.38−13.09 μm × 12.30−43.63 μm. Therefore, the isolates were identified as Alternaria alternata (Fr.) Keissl. The identification was then confirmed by CABI.AFLPbased dendrogram which revealed five clusters with a significant cophenetic correlation coefficient (r = 0.834) between the dendrogram and the original similarity matrix irrespective of their geographical origins. Eighteen (75%) of the Alternaria isolated from tomato leaves were clustered together in cluster I and five isolates formed two separate clusters, viz. cluster IV (T-Kh5 and T-H1) and cluster V (T-H4 and T-Med2). The remaining isolate, T-Am5, grouped with one of the potato isolates in cluster III. The other isolates which were recovered from potato, pepper and eggplants were all separated from the tomato isolates in the largest cluster.
Źródło:
Journal of Plant Protection Research; 2018, 58, 3
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Copper Addition on Pitting Corrosion of MA-Al
Autorzy:
Aranda, B.
Cuevas, F.
Cintas, J.
Herrera-García, M.
Urban, P.
Powiązania:
https://bibliotekanauki.pl/articles/1191707.pdf
Data publikacji:
2016-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.20.Ev
82.45.Bb
Opis:
This paper is intended to highlight the effect of copper addition on the pitting corrosion resistance of aluminium-base powder metallurgy parts. Results obtained on these mechanically alloyed (MA) specimens are compared with parts of MA-Al without added copper, as well as with commercial aluminium alloys. Immersion tests from 2 to 96 hours in 3.5% NaCl solutions, and potentiostatic techniques, were used to study the pitting corrosion. It was concluded that copper addition, in a similar way that in commercial aluminium alloys, produces a negative effect on the pitting corrosion resistance, because of the formation of Al₂Cu. These precipitates produce galvanic cells that favour the specimen pit. Therefore, increasing the copper content of MA-Al, although improving their ductility, worsens the pitting corrosion resistance of these alloys.
Źródło:
Acta Physica Polonica A; 2016, 129, 4; 788-791
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dielectric properties of papaya seeds from 75 kHz to 5 MHz
Autorzy:
Berbert, P.A.
Soares, K.J.
Moura, E.E.
Berbert-Molina, M.A.
Oliveira, M.T.R.
Martinazzo, A.P.
Powiązania:
https://bibliotekanauki.pl/articles/2082500.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
Carica papaya L.
dielectric loss factor
moisture content
relative permittivity
seed bulk density
Opis:
The object of this work was to study the dielectric properties of papaya seeds of the Golden cultivar and seeds of two papaya hybrids, Tainung and Calimosa, in the frequency range from 75 kHz to 5 MHz at four levels of bulk density, and with moisture contents ranging from 6 to 23% wet basis. The relative permittivity and the loss factor of the seeds were measured using a precision LCR meter, and their relationship with the variable frequency of the oscillating electric field, the seed moisture content and bulk density, and the cultivar/hybrid type were established. Relative permittivity for each value of the moisture content was reduced regularly as the frequency increased. Abrupt changes in the slopes of the curves demonstrating the relationship between the relative permittivity and the loss factor, and the moisture content were considered an indication of changes in the water sorption mechanisms occurring within the seed. The relationship between the relative permittivity and the loss factor, and bulk density was represented by linear functions with positive slopes. The effect of the cultivar or hybrid types on the relative permittivity and the loss factor revealed that seeds of the Golden cultivar and the Tainung hybrid exhibited similar relative permittivity values in the whole frequency range studied, in contrast to seeds of the Calimosa hybrid.
Źródło:
International Agrophysics; 2019, 33, 2; 185-192
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Winter Cover Crop Biomass on Summer Weed Emergence and Biomass Production
Autorzy:
Bittencourt, H.H.
Lovato, P.E.
Comin, J.J.
Lana, M.A.
Altieri, M.A.
Costa, M.D.
Gomes, J.C.
Powiązania:
https://bibliotekanauki.pl/articles/65024.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:
A greenhouse assay was carried out to evaluate the effect of winter cover crop residues on spontaneous plants that commonly occur on summer annual fields in Southern Brazil. Dry shoot residues of rye (Secale cereale), vetch (Vicia villosa), fodder radish (Raphanus sativus), and a mix of the three species, were applied over pots that had been seeded with alexandergrass (Brachiaria plantaginea), hairy beggarticks (Bidens pilosa), wild poinsettia (Euphorbia heterophylla), and morning glory (Ipomoea grandifolia) at four different depths (0, 1, 2, or 4 cm). Plant emergence and biomass production were measured. Residues of rye reduced the emergence of B. plantaginea, while vetch diminished I. grandifolia and B. plantaginea emergence. Fodder radish reduced emergence of I. grandifolia. The mix of cover crops reduced emergence of I. grandifolia, B. plantaginea, and B. pilosa. None of the cover crops differed from the control on E. heterophylla emergence. The lowest yields in spontaneous plant shoot biomass were obtained from the cover with rye + vetch + fodder radish. The lowest values of root biomass occurred under cover with rye, fodder radish or the mix. Use of vetch residues decreased emergence of B. plantaginea and I. grandifolia, but enhanced biomass accumulation by the latter.
Źródło:
Journal of Plant Protection Research; 2013, 53, 3
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Youngest agamid lizards from Western Europe (Sierra de Quibas, Spain, late Early Pleistocene)
Autorzy:
Blain, H.-A.
Bailon, S.
Agusti, J.
Pinero-Garcia, P.
Lozano-Fernandez, I.
Sevilla, P.
Lopez-Garcia, J.M.
Sanchez, G.R.
Mancheno, M.A.
Powiązania:
https://bibliotekanauki.pl/articles/21138.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Opis:
Here we report a new Early Pleistocene record of agamid lizards (Agamidae indet.) from the Spanish locality of Quibas (ca. 1.3–1.0 Ma), which represents the latest evidence of the family in Western Europe. Up to now, the family Agamidae was considered to have disappeared in this region at 1.8 Ma. This new record implies the survival of agamid lizards for a large part of the Early Pleistocene in the southernmost Iberian Peninsula, probably because of favourable climatic and environmental conditions. Consequently, the formerly detected Pliocene / Pleistocene boundary is no longer recognisable in the evolution of the herpetological assemblages in Western Europe.
Źródło:
Acta Palaeontologica Polonica; 2014, 59, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
X-ray microtomography (XMT) of fossil brachiopod shell interiors for taxonomy
Autorzy:
Blazejowski, B.
Binkowski, M.
Bitner, M.A.
Gieszcz, P.
Powiązania:
https://bibliotekanauki.pl/articles/23513.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
x-ray microtomography
fossil
brachiopod
shell
taxonomy
remains
paleontology
Terebratula terebratula
Opis:
The ability to see and understand the three−dimensional structure of an investigated object plays a key role in studying fossil remains. All living organisms are formed in threedimensions, but unfortunately fossilization processes often reduce overall shape, making it difficult to gather information about real overall appearance, functionality, and inner structure. Here, using a specimen of the brachiopod Terebratula terebratula we demonstrate a non−destructive technique for exploring the 3−D internal structure of fossil remains. The use of tomography allows the construction of a set of transverse serial sections in the manner used by brachiopod researchers for decades.
Źródło:
Acta Palaeontologica Polonica; 2011, 56, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Toksykologia współczesna nanomateriałów magnetycznych
Modern toxicology of magnetic nanomaterials
Autorzy:
Cywinska, M.A.
Grudzinski, I.P.
Powiązania:
https://bibliotekanauki.pl/articles/875401.pdf
Data publikacji:
2012
Wydawca:
Narodowy Instytut Zdrowia Publicznego. Państwowy Zakład Higieny
Tematy:
nanomaterialy
badania przedkliniczne
nanobiotechnologia
toksykologia
diagnostyka
teranostyka
toksykokinetyka
nanomagnetyki
nanomaterial
preclinical examination
nanobiotechnology
toxicology
diagnostics
theranostics
toxicokinetics
Opis:
Aktualny postęp w zakresie nanobiotechnologii doprowadził do rozwoju nowego obszaru nanomedycyny, związanego z aplikacją nano(bio)materiałów zarówno w celach diagnostycznych jak i terapeutycznych (teranostyki). Główne oczekiwania i wyzwania w powyższym zakresie dotyczą nanoproduktów magnetycznych, otrzymywanych metodami bioinżynierii, o potencjalnym zastosowaniu w transporcie leków, przede wszystkim leków przeciwnowotworowych, stosowanych w terapiach wykorzystujących określone molekularne punkty uchwytu. Wyjątkowe właściwości fizykochemiczne nanocząstek magnetycznych rokują nadzieję na rozwój współczesnej nanomedycyny nowotworów, stanowiąc między innymi technologiczny przełom w zakresie celowanego transportu leków i genów, terapii nowotworów z wykorzystaniem magnetycznej hipertermii, inżynierii tkankowej, znakowania komórek nowotworowych czy molekularnego obrazowania rezonansem magnetycznym. Wraz z szerokim zainteresowaniem magnetycznymi nanoproduktami bioinżynierii, w sferze szczególnej uwagi pozostaje ich potencjał toksyczny. Pokaźna ilość dotychczasowych dowodów naukowych sugeruje, że pewne właściwości nanocząstek magnetycznych (np. podwyższona aktywność powierzchniowa, zdolność do penetracji przez błony komórkowe, oporność na procesy biodegradacji) może zwiększać ich potencjał cytotoksyczny w porównaniu z odpowiadającymi im materiałami nieposiadającymi rozmiarów w nanoskali. Innymi słowy, ocena bezpieczeństwa przeprowadzona w odniesieniu do standardowych materiałów magnetycznych, może mieć ograniczone zastosowanie w ocenie ryzyka narażenia zdrowotnego i środowiskowego w przypadku nowych nanoproduktów magnetycznych otrzymanych metodami bioinżynierii. W niniejszym artykule dyskutujemy główne kierunki badawcze prowadzone w doświadczalnych modelach in vitro oraz in vivo w celu oceny toksyczności magnetycznych nanozwiązków, zwracając szczególną uwagę na problematykę analizy toksykologicznej nanomagnetyków. W pracy zaprezentowano ponadto nowe kierunki badawcze prowadzone na polu nanotoksykologii, podkreślając znaczenie rozwoju alternatywnych metod testowania magnetycznych nano(bio)produktów.
Current advances in nanobiotechnology have led to the development of new field of nanomedicine, which includes many applications of nano(bio)materials for both diagnostic and therapeutic purposes (theranostics). Major expectations and challenges are on bioengineered magnetic nanoparticles when their come to delivering drug compounds, especially to targeting anticancer drugs to specific molecular endpoints in cancer therapy. The unique physicochemical properties of these nanoparticles offer great promise in modern cancer nanomedicine to provide new technological breakthroughs, such as guided drug and gene delivery, magnetic hyperthermia cancer therapy, tissue engineering, cancer cell tracking and molecular magnetic resonance imaging. Along with the expanding interest in bio-engineered magnetic nanoproducts their potential toxicity has become one of the major concerns. To date, a number of recent scientific evidences suggest that certain properties of magnetic nanoparticles (e.g., enhanced reactive area, ability to cross cell membranes, resistance to biodegradation) may amplify their cytotoxic potential relative to bulk non-nanoscale counterparts. In other words, safety assessment developed for ordinary magnetic materials may be of limited use in determining the health and environmental risks of the novel bio-engineered magnetic nanoproducts. In the present paper we discuss the main directions of research conducted to assess the toxicity of magnetic nanocompounds in experimental in vitro and in vivo models, pointing to the key issues concerning the toxicological analysis of magnetic nanomaterials. In addition new research directions of nanotoxicological studies elucidating the importance of developing alternative methods for testing magnetic nano(bio)products are also presented.
Źródło:
Roczniki Państwowego Zakładu Higieny; 2012, 63, 3
0035-7715
Pojawia się w:
Roczniki Państwowego Zakładu Higieny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Genome size and phenotypic variation of Nymphaea (Nymphaeaceae) species from Eastern Europe and temperate Asia
Autorzy:
Dabrowska, M.A.
Rola, K.
Volkova, P.
Suda, J.
Zalewska-Galosz, J.
Powiązania:
https://bibliotekanauki.pl/articles/59355.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
genome size
phenotypic variation
Nymphaea alba
Nymphaea candida
Nymphaea tetragona
Nymphaea x borealis
Nymphaeaceae
morphometric analysis
flow cytometry
interspecies hybridization
Eastern Europe
temperate region
Asia
Opis:
Despite long-term research, the aquatic genus Nymphaea still possesses major taxonomie challenges. High phenotypic plasticity and possible interspecific hybridization often make it impossible to identify individual specimens. The main aim of this study was to assess phenotypic variation in Nymphaea taxa sampled over a wide area of Eastern Europe and temperate Asia. Samples were identified based on species-specific genome sizes and diagnostic morphological characters for each taxon were then selected. A total of 353 specimens from 32 populations in Poland, Russia and Ukraine were studied, with nine biometric traits being examined. Although some specimens morphologically matched N. xborealis (a hybrid between N. alba and N. Candida) according to published determination keys, only one hybrid individual was revealed based on genome size data. Other specimens with intermediate morphology possessed genome size corresponding to N. alba, N. Candida or N. tetragona. This indicates that natural hybridization between N. alba and N. Candida is not as frequent as previously suggested. Our results also revealed a considerably higher variation in the studied morphological traits (especially the quantitative ones) in N. alba and N. Candida than reported in the literature. A determination key for the investigated Nymphaea species is provided, based on taxonomically-informative morphological characters identified in our study.
Źródło:
Acta Societatis Botanicorum Poloniae; 2015, 84, 2
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Research on Characterization of Crushability for Foundry Sand Particles
Autorzy:
Dai, Y.
Ma, Q. Y.
Li, X. H.
Zhang, X.
Hu, F. P.
Zhang, Y.
Xie, W. D.
Powiązania:
https://bibliotekanauki.pl/articles/379689.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
foundry sand particle
mechanical load
AFS grain fineness
crushability
piasek odlewniczy
obciążenie mechaniczne
rozdrobnienie ziarna
Opis:
In this paper, crushability of foundry sand particles was studied. Three kinds of in-service silica sands in foundry enterprises selected as the study object, and foundry sand particles were subjected to mechanical load and thermal load during service were analyzed. A set of methods for simulating mechanical load and thermal load by milling and thermal-cold cycling were designed and researched, which were used to characterize the crushability for silica sand particles, the microstructure was observed by SEM. According to the user’s experience in actual application, the crushability of Sand C was the best and then Sand B, the last Sand A. The results indicated that mechanical load, thermal load and thermal-mechanical load can all be used to characterize the crushability of foundry sand particles. Microscopic appearances can qualitatively characterize the crushability of foundry sand particles to a certain extent, combining with the additions and cracks which are observed on the surface.
Źródło:
Archives of Foundry Engineering; 2017, 17, 4; 231-235
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Correlation between Copper Precipitation and Grown-In Oxygen Precipitates in 300 mm Czochralski Silicon Wafer
Autorzy:
Dong, P.
Ma, X.
Yang, D.
Powiązania:
https://bibliotekanauki.pl/articles/1361181.pdf
Data publikacji:
2014-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.72.Ff
61.72.Ji
61.72.Qq
61.72.Yx
61.72.Cc
Opis:
The behaviors of copper (Cu) precipitation along the radial direction of the 300 mm Czochralski grown silicon wafer have been investigated. It is found that the density of Cu precipitates decreases from the center to edge of the silicon wafer. Moreover, it is revealed that the density of grown-in oxygen precipitates also decreases along the radial direction as mentioned above. Therefore, it is apparent that the Cu precipitate density is positively correlative to the grown-in oxygen precipitate density. This is due to that the grown-in oxygen precipitates can serve as the heterogeneous nucleation centers for Cu precipitation. It is suggested that the Cu decoration in combination with preferential etching can be used to indirectly evaluate the radial distribution of grown-in oxygen precipitates in the silicon wafers.
Źródło:
Acta Physica Polonica A; 2014, 125, 4; 972-975
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Warp-knitted Fabric Defect Segmentation Based on the Shearlet Transform
Analiza defektów dzianin na bazie transformacji Shearleta
Autorzy:
Dong, Z.
Xia, D.
Ma, P.
Jiang, G.
Powiązania:
https://bibliotekanauki.pl/articles/234405.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
warp-knitted fabric defect
Shearlet transform
Fourier transform
segmented threshold de-nosing
defekt dzianiny
transformacja Shearleta
transformacja Fouriera
Opis:
The Shearlet transform has been a burgeoning method applied in the area of image processing recently which, differing from the Wavelet transform, has excellent properties in processing singularities for multidimensional signals. Not only is it similar to the performance of the Curvelet transform, it also overcomes the disadvantage of the Curvelet transform with respect to discretization. In this paper, the Shearlet transform with segmented threshold de-nosing is proposed to segment a warp-knitted fabric defect. Firstly a warp-knitted fabric image of size 512*512 is filtered by the Laplacian Pyramid transform and decomposed into low frequency and high frequency coefficients. Secondly the high frequency coefficients are operated with a pseudo-polar grid and then convoluted by the window function. Thirdly the shearlet coefficients will be obtained through redefining the Cartesian coordinates from the pseudo-polar grid coordinates and de-noised by the segmented threshold method. Then the coefficients which have high energy are selected for reconstruction in an inverse way using the previous steps. Finally the iterative threshold method and object operation based on morphology are applied to segment out the defect profile. The experiment’s result states that the Shearlet transform shows excellent performance in segmenting a common warp-knitted fabric defect, indicating that the segment results can be applied for further defect automatic recognition.
Transformacja Shearleta jest ostatnio dynamicznie rozwijającą się metodą stosowaną w dziedzinie przetwarzania obrazu, która różni się od transformaty Wavelet i ma doskonałe właściwości w przetwarzaniu sygnałów wielowymiarowych. Transformacja Shearleta ma prostszą implementację dyskretną, niż przekształcenie Curveleta w oparciu o rygorystyczne i proste ramy matematyczne. Może także dostarczyć bardziej elastycznego rozkładu na podstawie reprezentacji wieloskalowej i geometrycznej. Ostateczny wynik segmentacji uzyskano poprzez powtarzalną segmentację progową i operację morfologiczną. Wyniki wykazały, że segmentowy profil uszkodzeń jest dość wyraźny i porównywalny w porównaniu z pierwotnymi wadami dzianiny.
Źródło:
Fibres & Textiles in Eastern Europe; 2017, 5 (125); 87-94
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analytical electron microscopy investigation of topologically close-packed phases in CMSX-4 single crystal superalloy
Autorzy:
Dubiel, B.
Indyka, P.
Kalemba-Rec, I.
Moskalewicz, T.
Powiązania:
https://bibliotekanauki.pl/articles/1154000.pdf
Data publikacji:
2016-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.66.Dk
68.37.Hk
68.37.Lp
68.37.Ma
82.80.Ej
61.05.J-
Opis:
In this work the topologically close-packed phases precipitated during annealing of CMSX-4 single-crystal superalloy at temperature 1100°C were investigated. Microstructural analyses were carried out by means of scanning- and transmission electron microscopy as well as scanning-transmission electron microscopy in high angle annular dark field mode. Chemical composition in nanoareas was determined using energy dispersive X-ray spectroscopy. Scanning electron microscopy investigation has shown that the topologically close-packed precipitates were formed already after 50 h of annealing at temperature 1000°C. With prolongation of the annealing time up to 2500 h the change of the morphology of topologically close-packed particles from blocky to needle-like occurred. Selected area electron diffraction analysis indicated that the topologically close-packed precipitates are the orthorhombic P phase. Quantitative energy dispersive X-ray spectroscopy analysis revealed that the topologically close-packed precipitates are enriched mostly in Re and W.
Źródło:
Acta Physica Polonica A; 2016, 130, 4; 1110-1113
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analytical Electron Microscopy Studies of the CMSX-4 Single Crystal Superalloy Subjected to High Temperature Annealing
Autorzy:
Dubiel, B.
Indyka, P.
Kalemba-Rec, I.
Moskalewicz, T.
Powiązania:
https://bibliotekanauki.pl/articles/1033055.pdf
Data publikacji:
2017-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.66.Dk
68.37.Hk
68.37.Lp
68.37.Ma
82.80.Ej
Opis:
The aim of the present work is to investigate the development of the γ/γ' microstructure and the changes in chemical composition of γ and γ' phases during high temperature annealing of CMSX-4 superalloy at a temperature of 1100°C in the time range from 500 to 2500 h. The studies were performed by means of scanning electron microscopy and the modern scanning-transmission electron microscopy with Super-X EDS system of four SDD detectors. Results of scanning electron microscopy and scanning-transmission electron microscopy analyses have shown that the microstructure of CMSX-4 superalloy is unstable during ageing at high temperature and the coalescence of cuboidal γ' precipitates was observed. Energy dispersive X-ray microanalysis revealed the distribution of particular alloying elements in the γ and γ' phases and the differences in their concentration in the function of the annealing time.
Źródło:
Acta Physica Polonica A; 2017, 131, 5; 1375-1378
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new centrosaurine from the Late Cretaceous of Alberta, Canada, and the evolution of parietal ornamentation in horned dinosaurs
Autorzy:
Farke, A.A.
Ryan, M.J.
Barrett, P.M.
Tanke, D.H.
Braman, D.R.
Loewen, M.A.
Graham, M.R.
Powiązania:
https://bibliotekanauki.pl/articles/22176.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Opis:
In 1916, a centrosaurine dinosaur bonebed was excavated within the Campanian−aged deposits of what is now Dinosaur Provincial Park, Alberta, Canada. Specimens from this now−lost quarry, including two parietals, a squamosal, a skull missing the frill, and an incomplete dentary, were purchased by The Natural History Museum, London. The material was recently reprepared and identified herein as a previously unknown taxon, Spinops sternbergorum gen. et sp. nov. Based upon the available locality data and paleopalynology, the quarry lies in either the upper part of the Oldman Formation or the lower part of the Dinosaur Park Formation. The facial region of the partial skull is similar to putative mature specimens of Centrosaurusspp. and Styracosaurus albertensis, with short, rounded postorbital horncores and a large, erect nasal horncore. Parietal ornamentation is consistent on both known parietals and is unique among ceratopsids. Bilateral, procurved parietal hooks occupy the P1 (medial−most) position on the dorsal surface of the parietal and are very similar to those seen in Centrosaurus apertus. Epiparietals in the P2 or possibly P3 position (lateral to P1) manifest as extremely elongate, caudally directed spikes, unlike the condition in C. apertus, S. albertensis, or any other “derived” centrosaurine. Cladistic analysis suggests that S. sternbergorum is closely related to Centrosaurus and Styracosaurus. Historically, based upon the condition in Styracosaurus and related centrosaurines, it was assumed that the medial−most elongated spikes on centrosaurine parietals correspond to the P3 epiparietal position. The exception illustrated in the new taxon suggests that homologies of epiparietals among basal centrosaurines (e.g., Albertaceratops and Diabloceratops) and derived centrosaurines (e.g., Styracosaurus and “pachyrhinosaurs”) should be reconsidered. The medially−placed, caudally−directed “P3” process of basal centrosaurines may, in fact, be homologous with P2.
Źródło:
Acta Palaeontologica Polonica; 2011, 56, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł

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