Temat: IAB - Prolib Integro

Skocz do pozycji: 1.

Tytuł:: Pierwiastki syderofilne w meteorytach Morasko
Siderophile elements in the Morasko meteorites
Autorzy:: Pilski, Andrzej S.
Kryza, Ryszard
Wasson, John T.
Muszyński, Andrzej
Karwowski, Łukasz
Tematy:: Jankowo Dolne
Morasko
Seeläsgen
iron meteorites IAB
meteorites
siderophile elements; Pokaż więcej
Wydawca:: Polskie Towarzystwo Meteorytowe
Powiązania:: https://bibliotekanauki.pl/articles/1032939.pdf Link otwiera się w nowym oknie
Opis:: Sixteen specimens of the Morasko, one specimen of Seeläsgen and one specimen of Jankowo Dolne irons were analyzed with INAA to determine contents of 14 siderophile elements. The samples selected for analyses have their structures described and the presence or absence of cohenite checked. For preliminary interpretation, we have chosen elements determined with highest accuracy: Co, Ni, Ga, As, Ir and Au. The results are shown in tables and diagrams. It has been found that there are no significant differences in composition between fragments with and without cohenite. The observed low contents if iridium are not accompanied by lower contents of elements showing similar behavior during crystallization: platinum and tungsten, which suggests that fractional crystallization was not the reason of lower iridium content. Similar concentrations of elements have been found in all the Morasko specimens, and in the Seeläsgen and Jankowo Dolne irons, which suggests that all these meteorites come from one iron shower.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Polimineralne nodule w gruboziarnistym meteorycie Morasko
Polymineral nodules in coarse-grained Morasko meteorite
Autorzy:: Karwowski, Łukasz
Muszyński, Andrzej
Kryza, Ryszard
Pilski, Andrzej S.
Tematy:: Morasko iron IAB meteorite
altaite
graphite
meteorites
oxides
silicates
sulphides
troilite; Pokaż więcej
Wydawca:: Polskie Towarzystwo Meteorytowe
Powiązania:: https://bibliotekanauki.pl/articles/1032667.pdf Link otwiera się w nowym oknie
Opis:: Morasko meteorite (IAB octahedrite) contains numerous graphite-troilite inclusions. Within these inclusions, many mineral phases have been found, including native elements, sulphides, tellurides, oxides, phosphates and silicates. Apart from dominant graphite and troilite, the following minerals occur: copper, sphalerite, daubreelite, chromite, cosmochlor, enstatite, albite and orthoclase; phosphates (buchwaldite and brianite) are found occasionally, whereas djerfischerite, altaite, olivine and silica are rare. The mineral composition of the nodules suggests a more complex origin of the Morasko-type meteorites than currently assumed.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Geochemistry and growth morphology of alkali feldspar crystals from an IAB iron meteorite : insight into possible hypotheses of their crystallization
Autorzy:: Słaby, E.
Karwowski, Ł.
Majzner, K.
Wirth, R.
Muszyński, A.
Birski, Ł.
Simon, K.
Domonik, A.
Moszumańska, I.
Orłowski, R.
Tematy:: IAB
iron meteorite
alkali feldspar
trace elements
growth texture
perthite
antiperthite
melt contamination
target material; Pokaż więcej
Wydawca:: Polskie Towarzystwo Geologiczne
Powiązania:: https://bibliotekanauki.pl/articles/191796.pdf Link otwiera się w nowym oknie
Opis:: Alkali feldspar crystals have been recognized in the troilite-graphite nodules of the Morasko IAB iron meteorite. Their chemical, microtextural and structural properties were studied using electron microprobe analysis (EMPA), laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), transmission electron microscopy (TEM) and Raman spectroscopy. The feldspars occur as perthitic or antiperthitic intergrowths, whereas the albite lamellae are perfectly twinned. The structural properties reveal intergrown phases with fairly disordered patterns. The electron microprobe analyses demonstrate that the intergrown phases are mainly rich in sodium or potassium, resulting in compositions that are close to those of albite or orthoclase. The compositions, calculated on the basis of a segmented perthite-antiperthite image, showed that the Or-to-Ab proportions in the homogenized crystals were almost 0.3:0.7, thus indicating that the anorthoclase crystallized under high-temperature conditions. Two hypotheses of crystal formation could account for these characteristics: crystallization from a melt or from a metasomatic solution. Relics with evidence of metasomatic replacement of former minerals were not found. Accordingly, this work focuses on arguments that support the other hypothesis. Large ion lithophile elements (LILEs, e.g., Ba, Sr, Rb, LREE, Pb, and Ga) were used to track the origin of the crystals. Their concentrations indicate crystallization from a parent melt strongly depleted in LILEs. Alkali feldspar is commonly a product of a highly differentiated melt. However, highly differentiated melts are typically enriched in LILEs, which here is not the case. The melt that crystallized the feldspar cannot be related to impact-induced partial melting of the chondritic material alone. The derived melt probably was contaminated by silica-rich target material during interaction between the IAB projectile and the target material and was accompanied by metal and sulphide melts that were both immiscible with a silicate melt.
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Integrated Access and Backhaul based 5G Connectivity for Rural Indian Sectors : Ending the Digital Divide
Autorzy:: Biswas, Ardhendu Shekhar
Sil, Sanjib
Bera, Rabindranath
Mitra, Monojit
Tematy:: carrier aggregation
CA
component carrier
CC
5G
new radio
NR
integrated access and backhaul
IAB; Pokaż więcej
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Powiązania:: https://bibliotekanauki.pl/articles/2055209.pdf Link otwiera się w nowym oknie
Opis:: The world is heading towards deployment of 5G commercially by the year 2020. But providing broadband 5G connectivity to remote rural regions is a significant challenge. Fiber connectivity has attempted to penetrate rural regions but last mile connectivity is still a problem in many rural sectors due to improper land demarcation and hostile terrain. A scheme which is based on the Integrated Access and Backhaul (IAB) concept is proposed to provide last mile 5G connectivity to satisfy the broadband needs of rural subscribers. A wireless 5G downlink environment following 3GPP NR specifications with a significantly high throughput is simulated. The last mile link is provided through a 28GHz carrier from a proposed IAB node delivering a data throughput of 4.301 Gbps for single-user carrier aggregation and 5.733 Gbps for multi-user carrier aggregation which is quite promising for broadband service, like high-speed Internet and streaming video. The results presented in this work are observed to agree favourably with the results of other researchers in the field.
Dostawca treści:: Biblioteka Nauki

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