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Wyszukujesz frazę "L6" wg kryterium: Temat


Wyświetlanie 1-11 z 11
Tytuł:
The meteorite fall near Boumdeid, Mauritania, from September 14, 2011
Autorzy:
Buhl, S.
Toueirjenne, C.
Hofmann, B.
Laubenstein, M.
Wimmer, K.
Powiązania:
https://bibliotekanauki.pl/articles/411504.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Meteorytowe
Tematy:
Boumdeid (2011)
meteorite fall
Mauritania
trajectory scenario
L6 chondrite
cosmogenic radionuclides
Opis:
On the evening of September 14, 2011 at 21:00 GMT a bright bolide was observed by hundreds of eyewitnesses in the area north and west of the town of Kiffa, in the department of Assaba, in south Mauritania. A terminal fragmentation and sound phenomena were observed near the end point of the trajectory. At least one mass of 3.5 kg was observed to impact and recovered the morning after the fall near Boumdeid (or Bou Mdeid), around 60 km north of Kiffa. Subsequently a large number of eyewitness accounts were recorded and mapped by GPS. The present paper provides a scenario for the trajectory of the Boumdeid (2011) meteorite based on the available parameters and wind data at the relevant altitudes. In addition the paper presents the results of the mineralogical and chemical analysis of the recovered meteorite which is consistent with a classification as ordinary chondrite of type L6, shock stage S2, and a weathering grade of W0. Following its analysis and classification, the meteorite was published under the official name Boumdeid (2011) in Meteoritical Bulletin, no. 100, MAPS 49(8), (2014). Gamma ray spectroscopy was conducted 84 days after the fall and the detection of short-lived radionuclides such as 56Co and 46Sc confirmed the recency of the event. Derived from the data of 60Co, 54Mn and 22Na the approximate preatmospheric radius of the meteorite body was 10–20cm. The report is also intended to serve as a case example for post-event data recovery and trajectory reconstruction in areas not covered by sky-camera networks and with limited scientific infrastructure.
Źródło:
Meteorites; 2014, 3, No. 1-2; 5-18
2299-0313
2299-1220
Pojawia się w:
Meteorites
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nowy chondryt zwyczajny L6, S1, W1: Northwest Africa 11779
A new ordinary chondrite L6, S1, W1: Northwest Africa 11779
Autorzy:
Przylibski, Tadeusz A.
Łuszczek, Katarzyna
Kryza, Ryszard
Powiązania:
https://bibliotekanauki.pl/articles/1033133.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Meteorytowe
Tematy:
L6 chondrite
NWA chondrite
bulk chemistry
chemistry of minerals
meteorite
ordinary chondrite
Opis:
Based on petrological, mineralogical and geochemical research authors classified new meteorite Northwest Africa 11779 as the ordinary chondrite L6, S1, W1. Chemical composition of olivine crystals (Fa 24.9 mol.%) and of pyroxene crystals (Fs 19.4 mol.%) proved that this meteorite belongs to L chondrites. However, bulk chemical composition of NWA 11779 is not typical for L chondrites. Nevertheless, all analyzed elements (except Mo, Sn and Nb) are in abundances reported for L chondrites, some of elements have concentration closed to average abundances for L chondrites. The content of chosen, characteristic lithophile, siderophile and chalkophile elements in NWA 11779 chondrite is in most cases in accord with its typical abundance in L chondrites. Presence of poorly defined chondrules, secondary feldspar crystals larger than 50 µm in size, absence of glass within chondrules, coarse recrystallized matrix (with olivine crystals of 0.5 mm in diameter and pyroxene crystals of 0.3 mm in diameter) as well as carbon content below 0.2 wt% proved that studied meteorite belongs to the petrologic type 6. The only difference from characteristic features of petrologic type 6 in case of NWA 11779 chondrite is presence of ca. 10% of monoclinic Ca-poor pyroxenes. Undulatory extinction by olivine and absence of other shock features in this chondrite allow to determine the shock level as S1. Weathering grade of NWA 11779 was identified as W1 based on weathering of only FeNi alloy grains. The outer part of metallic grains as well as contact zones of FeNi and FeS are changed due to weathering. Between 10 and 20% of FeNi alloy grains are oxidized to iron oxides and hydroxides. These secondary products of weathering replace outer zone of FeNi grains and fill the small cracks, creating a few thin veins.
Źródło:
Acta Societatis Metheoriticae Polonorum; 2019, 10; 121-139
2080-5497
Pojawia się w:
Acta Societatis Metheoriticae Polonorum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sołtmany meteorite
Autorzy:
Karwowski, Ł.
Powiązania:
https://bibliotekanauki.pl/articles/411492.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Meteorytowe
Tematy:
meteorite
ordinary chondrite
L6 chondrite
meteorite fall
hammer meteorite
Warmia-Masuria Province
Sołtmany village
Opis:
This paper presents the results of a mineralogical and petrological study of the Sołtmany meteorite, which fell on April 30, 2011 in northern Poland. The meteorite was found almost immediately after it fell and has been little altered by weathering. Sołtmany is not the only observed fall of an L6 chondrite over Europe in the past few years. The preceding fall of this type, Jesenice (Slovenia), was also witnessed in April of 2009. However, it was not until several weeks after the fall that the first specimen of Jesenice was found, whereas Sołtmany was collected after a few minutes and submitted for analysis within a couple of days. The author presents mineral and petrographic features and chemical characteristics of mineral phases in Sołtmany. The mineral components are represented by metallic phases (kamacite, taenite, tetrataenite, native copper), as well as chromite, olivine, low and high-calcium pyroxene, feldspar, chlorine-bearing apatite, and merrillite. This study also describes the texture of the meteorite and takes notice of a low number of preserved chondrules and the presence of oval chondrule like areas, which exhibit a metamorphosed, recrystallized texture. Sołtmany was classified as an L6 ordinary chondrite with a weathering grade of W0. A shock stage S2 was determined on the basis of undulose extinction and lack of planar fractures in olivine crystals.
Źródło:
Meteorites; 2012, 2, No. 1-2; 15-30
2299-0313
2299-1220
Pojawia się w:
Meteorites
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Porównawcze badania mössbauerowskie meteorytów: Sołtmany (L6), Chelyabinsk (LL5) i Grzempy (H5)
Mössbauer comparative studies of the Sołtmany (L6), Chelyabinsk (LL5) and Grzempach (H5) meteorites
Autorzy:
Szlachta, Karol
Gałązka-Friedman, Jolanta
Woźniak, Marek
Powiązania:
https://bibliotekanauki.pl/articles/1033011.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Meteorytowe
Tematy:
Chelyabinsk (LL5)
Grzempy (H5)
Mössbauer spectroscopy
Sołtmany (L6)
classification of ordinary chondrites
meteorites
Opis:
Mössbauer studies of Chelyabinsk (LL5), Sołtmany (L6) and Grzempy (H5) show that the main iron bearing minerals in these meteorites are: Fe-Ni, troilite, olivine and pyroxene. Based on Mössbauer absorption area of different mineral phases, new set of parameters for classification of the ordinary chondrities were introduced. The most promising parameters are: the ratio of the olivine to pyroxene areas and the ratio of the silicate to metallic areas.
Źródło:
Acta Societatis Metheoriticae Polonorum; 2014, 5; 115-120
2080-5497
Pojawia się w:
Acta Societatis Metheoriticae Polonorum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rolnictwo ekologiczne i GMO szansą dla rozwoju polskiej gospodarki? Korzyści i zagrożenia
Organic Agriculture and GMO an Opportunity for the Development of Polish Economy? Benefits and Risks
Autorzy:
Ciepielewska, Magdalena
Powiązania:
https://bibliotekanauki.pl/articles/945512.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
żywienie człowieka
rolnictwo ekologiczne
żywność ekologiczna
GMO
gospodarka
zrównoważona konsumpcja
human nutrition
organic farming
organic food
economy
sustainable consumption
L6
L66
Opis:
Jakość spożywanego pożywienia, ilość zawartych w nim składników odżywczych czy witamin wpływa na stan zdrowia, aktywność fizyczną i psychiczną człowieka. Zatem bardzo ważne jest, by żywność przez nas spożywana była zdrowa, pełnowartościowa, bez hormonów wzrostu, antybiotyków czy metali ciężkich. W ostatnich latach rolnictwo ekologiczne rozwija się bardzo intensywnie na całym świecie, również w Polsce można zaobserwować wzrost powierzchni upraw ekologicznych oraz liczby przetwórni, a także jednostek certyfikujących. Także uprawy GM mogą stanowić dużą szansę dla rozwoju gospodarki, lecz konieczne jest wprowadzenie odpowiednich norm i przepisów regulujących owe uprawy. Problem z GMO jest taki, że nie zostało przeprowadzonych wystarczająco dużo testów i badań, które wykluczyłyby negatywny wpływ spożywania roślin GM na zdrowie ludzi. Świat stoi w obliczu narastającego problemu głodu, który uprawy GM mogłyby rozwiązać. Jednak, przed wprowadzeniem jakichkolwiek nasion czy sadzonek, które zostały zmodyfikowane genetycznie, należy być bardzo ostrożnym i skrupulatnie przeprowadzić wszelkie niezbędne badania.
The quality of food consumed and the amount of nutrients and vitamins it contains affects health as well as physical and psychological activity of man. Therefore, it is very important that the food we consume is healthy, of full value, without growth hormones, antibiotics or heavy metals. In recent years, organic agriculture has been developing very intensively all over the world. In Poland one can also observe an increase in organic crop areas, in number of organic processing plants and certification bodies. Also, GM crops can be a great opportunity for the development of economy, but it is necessary to introduce appropriate standards and regulations governing those cultivation. The problem with GMO is that not enough tests and studies which would exclude the negative impact of consuming GM vegetables and fruits on human health have been conducted. The world is facing the growing problem of famine that GM crops could solve. However, before introducing any seeds or seedlings that were subjected to genetic modifications, we must be extremely careful and meticulously carry out any necessary tests.
Źródło:
Gospodarka w Praktyce i Teorii; 2014, 4(37)
1429-3730
2450-095X
Pojawia się w:
Gospodarka w Praktyce i Teorii
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chondryt Sołtmany
Sołtmany chondrite
Autorzy:
Przylibski, Tadeusz A.
Powiązania:
https://bibliotekanauki.pl/articles/1033061.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Meteorytowe
Tematy:
Gefion family
L6
asteroid
atomic weight
bulk chemistry
cosmic-ray exposure age
cosmogenic radionuclides
density
fusion crust
magnetic susceptibility
meteorite
meteorite age
meteorite fall
mössbauer spectroscopy
noble gas
ordinary chondrite
organic matter
parent body
porosity
primordial radionuclides
thermophysical properties
troilite thermometer
Opis:
The Sołtmany hammer meteorite is classified as an ordinary chondrite type L6, W0, S2. At present it is the most thoroughly and comprehensively examined Polish meteorite. A comprehensive petrological, mineralogical and geochemical analysis alongside the investigation of its physical and particularly thermophysical properties, and, most of all, analyses of cosmogenic radionuclides and noble gases isotopes content, as well as the use of a troilite thermometer has made it possible to draw interesting conclusions concerning the genesis and evolution of the parent body and the history of the parent meteoroid and, finally, the Sołtmany meteorite. The present report attempts at summing up the results of studies conducted at several European research centres in the last four years. The age of the the Sołtmany chondrite parent rock has been defined at 4.137 billion years. It was formed at a temperature of up to 440–450 K (about 170°C), probably at a depth of up to 3 to 7 km under the surface of the parent body, i.e. at a pressure of the order of 1–2.4 kbar. Such a low temperature during the accretion, diagenesis and metamorphism of the parent body may point to its complicated development, which may be in part due to collisions of partially melted planetesimals. Like with other type L ordinary chondrites, one can infer that the parent body could have been destroyed about 467 million years ago, at the time of a catastrophic collision which led to the formation of Gefion family of planetoids. Perhaps one of the bodies in this family was involved in another collision about 29.2 million years ago, which resulted in ejecting the parent meteoroid of the Sołtmany chondrite onto the Earth collision trajectory. Before entering the Earth’s atmosphere, this meteoroid had the mass of about 36 kg and the diameter of ca 13.5 cm. During its flight through the atmosphere, it rotated and somersaulted, which resulted in the formation of an uniform thin (0.5–0.7 mm) fusion crust, whose temperature reached 1000°C. In the last phase, the Sołtmany meteorite fell almost vertically and its mass was a mere 3% of the mass of the parent meteoroid – 1.066 kg. It hit the roof and then the concrete stairs of a farm building, which caused it to break into two bigger and many small pieces. It was found a few minutes after the fall, which occurred at 6:03 a.m. (CEST, UTC+2:00) on 30 April 2011, by Wydmińskie Lake in northern Poland (54°00,53’N, 22°00,30’E). The Sołtmany chondrite is one of just 14 meteorites in which the activity concentration of the cosmogenic 52Mn has been determined, and one of the few ordinary chondrites where the concentration of organic matter has been defined. As a result, it was found out that unlike in carbonaceous CI chondrites, the composition of organic particles is dominated by less complex compounds (CHO and CHOS) than CHNO and CHNOS compounds. This may indicate the decomposition of more complex organic compounds into particles with simple structures during magmatic and metamorphic processes related to formation of type L ordinary chondrites.
Źródło:
Acta Societatis Metheoriticae Polonorum; 2016, 7; 93-122
2080-5497
Pojawia się w:
Acta Societatis Metheoriticae Polonorum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kierunkowy błąd systematyczny przy oznaczaniu kwasu L-askorbinowego metodami miareczkowymi
Sistematicheskaja oshibka vystupajushhaja pri oboznachenii L-askorbinovojj kisloty titrovannymi metodami
Systematic error in L-ascorbic acid determination by means of volumetric methods
Autorzy:
Bozyk, Z.
Powiązania:
https://bibliotekanauki.pl/articles/875669.pdf
Data publikacji:
1962
Wydawca:
Narodowy Instytut Zdrowia Publicznego. Państwowy Zakład Higieny
Tematy:
kwas L-askorbinowy
oznaczanie
metoda miareczkowa
2,6-dwuchlorofenoloidofenol
bledy systematyczne
L-ascorbic acid
determination
titration method
systematic error
Źródło:
Roczniki Państwowego Zakładu Higieny; 1962, 13, 3
0035-7715
Pojawia się w:
Roczniki Państwowego Zakładu Higieny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Surface Modification Of Implants For Bone Surgery
Modyfikacja powierzchni implantów ortopedycznych
Autorzy:
Marciniak, J.
Szewczenko, J.
Kajzer, W.
Powiązania:
https://bibliotekanauki.pl/articles/355874.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
AISI 316L stainless steel
Titanium alloy Ti6Al4V
surface layer
corrosion and wear resistance
biocompatibility
stal nierdzewna AISI 316L
stop tytanu Ti-6Al-4V
warstwa powierzchniowa
korozja i odporność na ścieranie
biokompatybilność
Opis:
The study discusses the methods of surface modification methods for AISAI 316 L steel and Ti6Al4V ELI titanium alloy, dedicated to complex design implants used in bone surgery. Results of structural tests have been presented along with those evaluating the physicochemical properties of the formed surface layers. Clinical feasibility of the surface layers has also been evaluated. The developed surface modification methods improved the resistance to pitting, crevice and stress corrosion and ensured better biocompatibility. Moreover, the layers formed are marked by plasticity. Results of the tests performed show applicability of the evaluated methods of surface modification in complex shape implants for the clinical use.
W pracy omówiono metody modyfikacji powierzchni stali AISAI 316 L oraz stopu tytanu Ti6Al4V ELI przeznaczonych na implanty o złożonej konstrukcji stosowanych w chirurgii kostnej. Przedstawiono wyniki badań struktury oraz własności fizykochemicznych wytworzonych warstw wierzchnich. Określono również przydatność wytworzonych warstw do zastosowań klinicznych. Opracowane metody modyfikacji powierzchni zwiększyły odporność na korozję wżerową, szczelinową i naprężeniową oraz poprawiły biokompatybilności. Ponadto wytworzone warstwy cechują się podatnością do odkształceń. Wyniki badań wykazały przydatność zastosowanych metod modyfikowania powierzchni implantów o złożonych kształtach do zastosowań klinicznych.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 3; 2123-2129
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-11 z 11

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