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Wyszukujesz frazę "Martin, M.P." wg kryterium: Autor


Wyświetlanie 1-9 z 9
Tytuł:
Vascular structure of the earliest shark teeth
Autorzy:
Martínez-Pérez, C.
Martín-Lazaro, A.
Ferrón, H. G.
Kirstein, M.
Donoghue, P. C. J.
Botella, H.
Powiązania:
https://bibliotekanauki.pl/articles/139170.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Leonodus
Celtiberina
early chondrichthyans
Lower Devonian
synchrotron tomography
vascular system
ryby chrzęstnoszkieletowe
ryby chrzęstne
chrzęstniki
dolny dewon
tomografia
układ naczyniowy
Opis:
Here we use synchrotron tomography to characterise dental vasculature in the oldest known tooth-bearing sharks, Leonodus carlsi Mader, 1986 and Celtiberina maderi Wang, 1993. Three dimensional reconstruction of the vascular system and microstructure of both taxa revealed a complex and dense network of canals, including horizontal, ascending and secondary bifurcated canals, as well as histological features consistent with an osteodont histotype. However, L. carlsi and C. maderi also exhibit significant morphological differences, showing Leonodus a typical diplodont tooth morphology with a linguo-labially elongated base, that contrast with Celtiberina’s teeth that show a single conical cusp curved lingually with a week developed flat base mesio-distally extended, perhaps reflecting distant relationship. These data are compatible with a pre-Devonian diversification of the two main tooth types traditionally recognised in Palaeozoic sharks (i.e., “cladodont” vs “diplodont”). Finally, our data demonstrate that existing dental classification schemes based on styles of vascularisation are over-simplified, especially when Palaeozoic taxa are considered.
Źródło:
Acta Geologica Polonica; 2018, 68, 3; 457-465
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Taxonomic implications of the residual colour patterns of ampullinid gastropods and their contribution to the discrimination from naticids
Autorzy:
Caze, B.
Merle, D.
Le Meur, M.
Pacaud, J.-M.
Ledon, D.
Sain Martin, J.-P.
Powiązania:
https://bibliotekanauki.pl/articles/20897.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
taxonomy
residual colour pattern
ampullinid gastropod
gastropod
contribution
discrimination
naticid
Ampullinidae
Naticidae
shell
evolution
Cainozoic
Europe
Ampullina
Globularia
Crommium
Amaurellina
Pachycrommium
Amauropsina
Ampullonatica
Eocernina
Ampullinopsis
Vanikoropsis
Pictavia
Ampullospira
Deshayesia
Cernina
Opis:
The diversity of residual colour patterns is revealed for the first time in the European fossil Ampullinidae. The colour patterns were studied under Ultraviolet (UV) light in approximately 3100 specimens belonging to 83 species, 12 genera (Ampullina, Globularia, Crommium, Amaurellina, Pachycrommium, Amauropsina, Ampullonatica, Eocernina, Ampullinopsis, Vanikoropsis, Pictavia, and Ampullospira) and three subgenera (Globularia, Deshayesia, and Cernina within the genus Globularia). Forty−six Cainozoic species revealed residual colour patterns and 29 of them, belonging to six genera (Ampullina, Globularia, Crommium, Amaurellina, Pachycrommium, Amauropsina), are described herein as examples representing the entire diversity of the encountered colour patterns. These patterns are most diverse during the Middle Eocene coincident with the period of highest taxonomic diversity of the Ampullinidae. Four basic classes, regarded as containing possible homologous colour patterns in terms of pigments incorporation modalities, are proposed. Class I, a fluorescent wide diffuse area or spiral stripes, occurs in most of the species, while the three others are more peculiar. Class II, fluorescent axial zigzagging stripes, Class III, fluorescent axial to slightly opisthocline stripes or segments, and Class IV, fluorescent patches forming axial segments by coalescence, allow an easy distinction between the genera Globularia, Pachycrommium, and three peculiar species of Ampullina. The bauplan of the colour patterns revealed in Globularia is very similar to that of the single extant species, Globularia (Cernina) fluctuata. This supports the view of previous authors who classified them in the same genus. Furthermore, at the family level, the peculiar residual patterns belonging to classes II, III, and IV have not been observed in naticid gastropods. Thus our results for the Cainozoic fossil record are consistent with the conclusions based on anatomy and feeding habits, namely that ampullinid gastropods, regarded for a long time as belonging to the family Naticidae, constitute a family apart.
Źródło:
Acta Palaeontologica Polonica; 2011, 56, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance of a drop-in biofuel emulsion on a single-cylinder research diesel engine
Autorzy:
Bogarra-Macias, M.
Doustdar, O.
Fayad, M. A.
Wyszyński, M. L.
Tsolakis, A.
Ding, P.
Pacek, A.
Martin, P.
Overend, R.
O'Leary, S.
Powiązania:
https://bibliotekanauki.pl/articles/133126.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
pyrolysis oil
emulsion
wood pyrolysis
engine testing
olej popirolityczny
emulsja
piroliza drewna
badania silnika
Opis:
Current targets in reducing CO2 and other greenhouse gases as well as fossil fuel depletion have promoted the research for alternatives to petroleum-based fuels. Pyrolysis oil (PO) from biomass and waste oil is seen as a method to reduce life-cycle CO2, broaden the energy mix and increase the use of renewable fuels. The abundancy and low prices of feedstock have attracted the attention of biomass pyrolysis in order to obtain energy-dense products. Research has been carried out in optimising the pyrolysis process, finding efficient ways to convert the waste to energy. However, the pyrolysis products have a high content in water, high viscosity and high corrosiveness which makes them unsuitable for engine combustion. Upgrading processes such as gasification, trans-esterification or hydro-deoxynegation are then needed. These processes are normally costly and require high energy input. Thus, emulsification in fossil fuels or alcohols is being used as an alternative. In this research work, the feasibility of using PO-diesel emulsion in a single-cylinder diesel engine has been investigated. In-cylinder pressure, regulated gaseous emissions, particulate matter, fuel consumption and lubricity analysis reported. The tests were carried out of a stable non-corrosive wood pyrolysis product produced by Future Blends Ltd of Milton Park, Oxfordshire, UK. The product is trademarked by FBL, and is a stabilized fraction of raw pyrolysis oil produced in a process for which the patent is pending. The results show an increase in gaseous emissions, fuel consumption and a reduction in soot. The combustion was delayed with the emulsified fuel and a high variability was observed during engine operation.
Źródło:
Combustion Engines; 2016, 55, 3; 9-16
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
NATO Standards and Practice for Munitions Safety and Insensitive Munitions
Autorzy:
Baker, E.
Voort, M. van der
Martin, P.
Powiązania:
https://bibliotekanauki.pl/articles/403272.pdf
Data publikacji:
2018
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
NATO
standards
munitions
safety
Insensitive Munitions
Opis:
The NATO Munitions Safety Information Analysis Center (MSIAC) is a multinational collaboration that collects, stores, and analyses technical information related to Munitions Safety (MS) and Insensitive Munitions (IM). MSIAC supports its member nations through a variety of products and services. Poland is becoming a MSIAC member nation during 2018. MSIAC has a diverse programme of work aimed at developing and sharing the related underpinning scientific knowledge. This is then applied to support policy implementation and development related to munition safety. This paper provides an overview of: NATO policies for MS related to the storage and transport of munitions; NATO IM requirements and testing; and how they relate to Poland. In particular, a comparison of NATO munitions storage policy with Poland munitions storage regulations has identified some differences. These differences are discussed.
Źródło:
Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa; 2018, 9, 3 (33); 7-14
2081-5891
Pojawia się w:
Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Battarrea phalloides in Macedonia: genetic variability, distribution and ecology
Autorzy:
Martin, M.P.
Rusevska, K.
Duenas, M.
Karadelev, M.
Powiązania:
https://bibliotekanauki.pl/articles/67172.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
Battarrea phalloides
Gasteromycetes
Basidiomycota
Macedonia
genetic variability
distribution
ecology
biodiversity
taxonomy
Opis:
Morphological and molecular analyses of Battarrea phalloides from Macedonia were done. While B. phalloides specimens shown three kind of spore ornamentation, each one related to a clade in the phylogenetic ITS nrDNA tree; all specimens from Macedonia shown spores with anastomosing truncate ridges and very low variability of the ITS nrDNA sequences. The low genetic variability of these specimens, could be because of genetic drift.
Źródło:
Acta Mycologica; 2013, 48, 1
0001-625X
2353-074X
Pojawia się w:
Acta Mycologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Automatic method for spectral pattern association with characteristic frequencies
Metoda automatycznego łączenia schematów spektralnych z charakterystycznymi częstotliwościami
Autorzy:
Firla, M.
Gerber, T.
Bellemain, P.
Martin, N.
Powiązania:
https://bibliotekanauki.pl/articles/328595.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:
condition monitoring
characteristic fault frequencies
wind shaft turbine
diagnosis
monitorowanie stanu
częstotliwości charakterystyczne uszkodzeń
diagnostyka
wał
turbina wiatrowa
Opis:
This paper proposes an advanced signal-processing technique to improve the condition monitoring of rotating machinery. The proposed method employs the results of a blind spectrum interpretation including harmonic and sideband series detection. The contribution of this paper is an algorithm for automatic association of harmonic and sideband series with the characteristic fault frequencies listed in the kinematic configuration of the monitored system. The proposed algorithm is efficient in inspection of real-world signals, which contain a vast number of detected spectral components. The proposed approach has the advantage of taking into account a possible slip of the rolling-element bearings. The performance of the proposed algorithm is illustrated on real-world data by investigating a shaft problem of an industrial wind turbine high-speed shaft.
W artykule zaproponowano zaawansowaną technikę przetwarzania sygnałów w celu poprawy monitorowania stanu maszyn wirujących. Przedstawiona metoda wykorzystuje wyniki ślepej interpretacji widma sygnału, m. in. detekcję serii harmonicznych i wstęg bocznych. Wkład zaprezentowany w tym artykule to algorytm do automatycznego łączenia serii harmonicznych oraz wstęg bocznych z charakterystycznymi częstotliwościami dostępnymi na podstawie konfiguracji kinematycznej monitorowanej maszyny. Zaproponowany algorytm jest skuteczny w badaniu sygnałów rzeczywistych, które zawierają dużą liczbę wykrytych elementów widmowych. Zaletą zaproponowanej metody jest uwzględnianie możliwego poślizgu łożyska tocznego. Działanie zaproponowanego algorytmu zostało zilustrowane na przykładzie rzeczywistych danych, który pokazuje problem wału wysokoobrotowego przemysłowej turbiny wiatrowej.
Źródło:
Diagnostyka; 2015, 16, 4; 77-84
1641-6414
2449-5220
Pojawia się w:
Diagnostyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An NMR study of Pr$\text{}_{0.5}$Ca$\text{}_{0.5}$Mn$\text{}_{1-x}$Ga$\text{}_{x}$O$\text{}_{3}$ (x=0 and 0.03)
Autorzy:
Oates, C. J.
Kapusta, Cz.
Riedi, P. C.
Sikora, M.
Zając, D.
Rybicki, D.
Martin, C.
Yaicle, C.
Maignan, A.
Powiązania:
https://bibliotekanauki.pl/articles/2037129.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
76.60.-k
75.47.Gk
Opis:
An NMR study of polycrystalline Pr$\text{}_{0.5}$Ca$\text{}_{0.5}$Mn$\text{}_{1-x}$Ga$\text{}_{x}$O$\text{}_{3}$ (x=0 and 0.03) at 3 K is presented. Zero field spin-echo spectra of the Ga doped compound consist of an overlapping $\text{}^{69,71}$Ga signal at 74~MHz (hyperfine field of 5.3 T), a $\text{}^{55}$Mn double exchange line at 375 MHz (35.5 T) and a weak Mn$\text{}^{3+}$ signal between 400 and 550 MHz. Measurements in an applied field show a step-like increase in the double exchange line intensity, which corresponds to an increase in the amount of the ferromagnetic metallic phase. This coincides with a step-like feature in the bulk magnetization measurements. The effect is similar to that in the previous field dependent $\text{}^{55}$Mn NMR measurements of Pr$\text{}_{0.67}$Ca $\text{}_{0.33}$MnO$\text{}_{3}$. At the demagnetized and remanent state, a variation of spin- spin relaxation time, T$\text{}_{2}$, across the $\text{}^{55}$Mn line, due to the Suhl-Nakamura interaction is observed, which suggests that the ferromagnetic metallic double exchange regions, at liquid helium temperatures, are at least 4 nm in size.
Źródło:
Acta Physica Polonica A; 2004, 105, 1-2; 189-195
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A mysterious giant ichthyosaur from the lowermost Jurassic of Wales
Autorzy:
Martin, J.E.
Vincent, P.
Suan, G.
Sharpe, T.
Hodges, P.
Williams, M.
Howells, C.
Fischer, V.
Powiązania:
https://bibliotekanauki.pl/articles/23272.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
ichthyosaur
deposit
morphotype
Jurassic
Wales
Opis:
Ichthyosaurs rapidly diversified and colonised a wide range of ecological niches during the Early and Middle Triassic period, but experienced a major decline in diversity near the end of the Triassic. Timing and causes of this demise and the subsequent rapid radiation of the diverse, but less disparate, parvipelvian ichthyosaurs are still unknown, notably because of inadequate sampling in strata of latest Triassic age. Here, we describe an exceptionally large radius from Lower Jurassic deposits at Penarth near Cardiff, south Wales (UK) the morphology of which places it within the giant Triassic shastasaurids. A tentative total body size estimate, based on a regression analysis of various complete ichthyosaur skeletons, yields a value of 12-15 m. The specimen is substantially younger than any previously reported last known occurrences of shastasaurids and implies a Lazarus range in the lowermost Jurassic for this ichthyosaur morphotype.
Źródło:
Acta Palaeontologica Polonica; 2015, 60, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A different path to the summit of Fusarium Head Blight resistance in wheat: developing germplasm with a systemic approach.
Autorzy:
Comeau, A.
Langevin, F.
Caetano, V.R
Haber, S.
Savard, M.E.
Voldeng, H.
Fedak, G.
Dion, Y.
Rioux, S.
Gilbert, J.
Martin, R.A.
Eudes, F.
Scheeren, P.L.
Powiązania:
https://bibliotekanauki.pl/articles/2199597.pdf
Data publikacji:
2011-06-21
Wydawca:
Instytut Hodowli i Aklimatyzacji Roślin
Tematy:
barley yellow dwarf virus (BYDV)
biotic and abiotic stresses
Fusarium Head Blighy (FHB)
genotypes
resistance
traits interaction
Opis:
In pursuing FHB resistance in wheat, 30 years of conventional breeding efforts in Eastern Canada have brought some progress. Substantial investment and the application in recent years of marker-assisted selection have to date, however, failed to produce agronomic lines that resist FHB as well as Sumai 3. We present here an alternative path, described as the systemic approach. Rather than seeking to introgress specific putative resistance genes, it subjects target germplasm to regimes of repeated cycles of multiple, interacting (biotic and abiotic) stresses in which desirable traits – not always adequately expressed in parental lines – are identified and selected. How can such a seemingly counterintuitive process work? The systemic approach views desired resistance as arising from the interactions of complex regulation mechanisms mediating how a host responds when a pathogen attacks. These constituents of resistance should thus not always be understood simply as discrete Mendelian units. In repeated rounds of selection, the systemic approach captures those rare individuals that embody optimal interactions of traits, and advances them as founders of lines that resist FHB more effectively than if selection focused on FHB alone. In Quebec, we have chosen to select wheat populations under combined pressure from barley yellow dwarf virus (BYDV) infection and FHB. Resistance to FHB and tolerance of BYDV are quantitative traits that interact. BYD increases both the direct losses from FHB and the production of mycotoxins. Selection under virus pressure, therefore, helps identify those individuals which express FHB resistance more effectively. Moreover, the correlates of virus tolerance (physiological efficiency, generalized stress tolerance and yield) point to those plants with better root traits, ability to produce biomass and yield stability. Together with numerous secondary criteria, such selection eliminates all but a few ‘winners’ in each round. Seen from a systemic perspective, the difficulty of identifying good progeny among descendants of crosses with Sumai 3 does not surprise. Deleterious linkages, pleiotropy and epistasis will usually combine in far from optimal expressions of the assembled genetic information. The systemic approach, by contrast, identifies in repeated cycles increasingly optimized expressions of genes, allowing all potential sources of resistance to be explored. Thus resistant lines can readily be derived from the crosses of susceptible parents, an objective rarely sought in conventional, focused approaches. Moreover, wheat plants respond to the systemic approach’s powerful stresses with enhanced epigenetic variation, raw material from which broader ranges of heritable traits can be selected. Germplasm that expresses a full range of attractive traits while resisting FHB as effectively as Sumai 3 can now be shown to be much more abundant than previously imagined. Perhaps this promise will entice more wheat workers to try a systemic approach...
Źródło:
Plant Breeding and Seed Science; 2011, 63; 39-48
1429-3862
2083-599X
Pojawia się w:
Plant Breeding and Seed Science
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-9 z 9

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