Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "gadolinium" wg kryterium: Temat


Wyświetlanie 1-11 z 11
Tytuł:
Toxicological and cytophysiological aspects of lanthanides action.
Autorzy:
Pałasz, Artur
Czekaj, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/1044234.pdf
Data publikacji:
2000
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
gadolinium
cytochrome P450.
calcium
lanthanides
metals
Opis:
Lanthanides, also called rare-earth elements, are an interesting group of 15 chemically active, mainly trivalent, f-electronic, silvery-white metals. In fact, lanthanides are not as rare as the name implies, except for promethium, a radioactive artificial element not found in nature. The mean concentrations of lanthanides in the earth's crust are comparable to those of life-important elements like iodine, cobalt and selenium. Many lanthanide compounds show particular magnetic, catalytic and optic properties, and that is why their technical applications are so extensive. Numerous industrial sources enable lanthanides to penetrate into the human body and therefore detailed toxicological studies of these metals are necessary. In the liver, gadolinium selectively inhibits secretion by Kupffer cells and it decreases cytochrome P450 activity in hepatocytes, thereby protecting liver cells against toxic products of xenobiotic biotransformation. Praseodymium ion (Pr3+) produces the same protective effect in liver tissue cultures. Cytophysiological effects of lanthanides appear to result from the similarity of their cationic radii to the size of Ca2+ ions. Trivalent lanthanide ions, especially La3+ and Gd3+, block different calcium channels in human and animal cells. Lanthanides can affect numerous enzymes: Dy3+ and La3+ block Ca2+-ATPase and Mg2+-ATPase, while Eu3+ and Tb3+ inhibit calcineurin. In neurons, lanthanide ions regulate the transport and release of synaptic transmitters and block some membrane receptors, e.g. GABA and glutamate receptors. It is likely that lanthanides significantly and uniquely affect biochemical pathways, thus altering physiological processes in the tissues of humans and animals.
Źródło:
Acta Biochimica Polonica; 2000, 47, 4; 1107-1114
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of MOSFETs with crystalline high-k gate-dielectrics: device simulation and experimental data
Autorzy:
Zaunert, F.
Endres, R.
Stefanov, Y.
Schwalke, U.
Powiązania:
https://bibliotekanauki.pl/articles/308785.pdf
Data publikacji:
2007
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
crystalline high-k gate dielectric
rare-earth oxide
praseodymium oxide
gadolinium oxide
damascene metal gate
CMP
CMOS process
TSUPREM4
MEDICI
interface state density
carrier mobility
remote coulomb scattering
Opis:
The evaluation of the world's first MOSFETs with epitaxially-grown rare-earth high-k gate dielectrics is the main issue of this work. Electrical device characterization has been performed on MOSFETs with high-k gate oxides as well as their reference counterparts with silicon dioxide gate dielectric. In addition, by means of technology simulation with TSUPREM4, models of these devices are established. Current-voltage characteristics and parameter extraction on the simulated structures is conducted with the device simulator MEDICI. Measured and simulated device characteristics are presented and the impact of interface state and fixed charge densities is discussed. Device parameters of high-k devices fabricated with standard poly-silicon gate and replacement metal gate process are compared.
Źródło:
Journal of Telecommunications and Information Technology; 2007, 2; 78-85
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rare Earth Silicate Formation: A Route Towards High-k for the 22 nm Node and Beyond
Autorzy:
Mitrovic, I. Z.
Hall, S.
Powiązania:
https://bibliotekanauki.pl/articles/308255.pdf
Data publikacji:
2009
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
gadolinium silicate
interfacial layer
lanthanides
rare earth oxides
Opis:
Over the last decade there has been a significant amount of research dedicated to finding a suitable high-k/metal gate stack to replace conventional SiON/poly-Si electrodes. Materials innovations and dedicated engineering work has enabled the transition from research lab to 300 mm production a reality, thereby making high-k/metal gate technology a pathway for continued transistor scaling. In this paper, we will present current status and trends in rare earthbased materials innovations; in particular Gd-based, for the high-k/metal gate technology in the 22 nm node. Key issues and challenges for the 22 nm node and beyond are also highlighted.
Źródło:
Journal of Telecommunications and Information Technology; 2009, 4; 51-60
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of the generally available WIMS versions to modern PWRs
Autorzy:
Kulikowska, T.
Stadnik, A.
Andrzejewski, K.
Boettcher, A.
Powiązania:
https://bibliotekanauki.pl/articles/147884.pdf
Data publikacji:
2012
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
reactor calculations
lattice spectrum code
resonance integrals
gadolinium bearing fuel
Opis:
The generally available versions of WIMS (Winfrith improved multigroup scheme) code have been used at the Institute of Atomic Energy POLATOM (IEA POLATOM, Otwock/Świerk, Poland) for a variety of reactor lattice analyses since 1974. With planned construction of new generation PWRs (power water reactors) in Poland, a question of WIMSD-5B version applicability to lattice calculations of strongly heterogeneous assemblies with gadolinium poisoned pins became actual. The present paper deals with modeling of the fuel assemblies using the version of WIMSD-5B extended at the IEA POLATOM. It was shown that with a careful choice of computational options the code properly describes main physical parameters of modern PWR fuel assemblies.
Źródło:
Nukleonika; 2012, 57, 1; 87-93
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect Of The Gadolinium Oxide Addition On The Electrical Properties Of Tetragonal Zirconium Dioxide
Wpływ dodatku tlenku gadolinu na właściwości elektryczne tetragonalnego tlenku cyrkonu
Autorzy:
Cyran, J.
Wyrwa, J.
Drożdż, E.
Dziubaniuk, M.
Rękas, M.
Powiązania:
https://bibliotekanauki.pl/articles/351961.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
gadolinium (III) oxide
tetragonal zirconia
electrical properties
grain boundary conductivity
tlenek gadolinu
tetragonalny tlenek cyrkonu
właściwości elektryczne
przewodnictwo po granicy ziaren
Opis:
The aim of this work was examination of gadolinium-doped 3YSZ electrical and structural properties. Such materials may be used as electrolytes in intermediate temperature solid oxide fuel cells (IT-SOFC). First step of the research was synthesis of 3YSZ with different contents of gadolinium (0.25; 0.5; 1.0 at %). Prepared materials were characterized by high porosity. No effect of gadolinium addition on grain size was observed. The experimentally determined values of grain interiors electrical conductivities for gadolinium doped samples are comparable to grain interior conductivities of gadolinium free tetragonal zirconia. On the other hand, a clear effect of gadolinium addition on electrical conductivity of grain boundaries was observed. It was found that 3YSZ containing 0.25 at. % Gd was the most promising from the investigated materials as a solid electrolyte for IT SOFC.
Celem pracy było zbadanie strukturalnych i elektrycznych właściwości dwutlenku cyrkonu stabilizowanego 3% mol. tlenkiem itru (3YSZ) z dodatkiem gadolinu. Tego typu materiał może znaleźć zastosowanie jako elektrolit w średniotemperaturowych stało-tlenkowych ogniwach paliwowych (IT-SOFC). Pierwszym etapem badań była synteza 3YSZ z różną ilością wprowadzonego gadolinu (0.25; 0.5; 1.0 at %). Otrzymane materiały charakteryzowały się wysoką porowatością. Nie zaobserwowano wpływu dodatku gadolinu na wielkość ziaren. Wyznaczone eksperymentalnie wartości przewodnictwa objętości ziaren są porównywalne z wartością przewodnictwa objętości ziaren wykazywanego przez czysty 3YSZ (bez dodatku gadolinu). Z drugiej strony, zaobserwowano znaczny wpływ dodatku gadolinu na przewodnictwo po granicach ziaren. Stwierdzono również, że 3YSZ zawierający 0.25% at. gadolinu był najbardziej obiecującym z badanych materiałów pod kątem zastosowania jako elektrolit w IT – SOFC.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 2A; 993-998
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Production and properties of composite material comprising Gd multiscale particles
Autorzy:
Jaworski, J.
Gawłowski, G.
Powiązania:
https://bibliotekanauki.pl/articles/407095.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
gadolinium
producing
Gd particles
multiscale particles
paraffin
AC electric discharge
Opis:
The article presents a novel method of producing Gd particles and preserving them from oxidation. The particles were produced in liquid paraffin by means of AC electric discharge and stored in the solidified paraffin. After seven months, the surface of the Gd was found to be exempt of oxidation. Moreover a composite material formed from mixing paraffin with Gd particles was conductive and magnetic and also presented photovoltaic effect. This method is a promising means of producing, at an industrial scale, particles from materials extremely sensitive to environment such as rare earth materials. Also the new material consisted of Gd particles in a paraffin matrix can find applications in many branches of industry.
Źródło:
Management and Production Engineering Review; 2015, 6, 1; 16-20
2080-8208
2082-1344
Pojawia się w:
Management and Production Engineering Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The use of gadolinium and europium concentrations as contaminant tracers in the Nida River watershed in south-central Poland
Autorzy:
Migaszewski, Z. M.
Gałuszka, A.
Powiązania:
https://bibliotekanauki.pl/articles/2060198.pdf
Data publikacji:
2016
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
are earth elements
wastewater effluent
Nida River drainage system
anthropogenic gadolinium
geogenic europium
Opis:
This paper presents the results of rare earth element (REE) determinations in the Nowiny wastewater treatment plant (NWWTP) effluents and Nida River system waters of the southeastern Kielce Region (south-central Poland). Of the REE examined, gadolinium and europium turned out to be very useful for pinpointing anthropogenic and geogenic sources. Anthropogenic gadolinium (Gdanth), used as a contrasting agent in magnetic resonance imaging (MRI), is released from the NWWTP into the river drainage system. This micropollutant is traced downstream over the distance of about 15 km. This river stretch is characterized by a strong positive NASC-normalized Gdanth anomaly with the GdNASC/GdNASC* ratio above 1.1 (1.80–15.57) and the Gdanth input varying from 44 to 94%. Two additional positive Gdanth anomalies recorded in the rivers Bobrza and Nida point out to mixing of effluents derived from the NWWTP and other local wastewater treatment plants. In contrast, the Gdanth-uncontaminated waters upstream, or downstream far away from the NWWTP display a distinct positive NASC-normalized Eu anomaly highlighted by a high Eu/Eu* ratio in the range of 2.87 to 29.70. The lack of Gdanth anomaly upstream from the NWWTP also indicates that there is no leakage of municipal sewage from the sanitary collector sewer into the Silnica River. Thus Gd as a contaminant may be effectively used as a tracer in similar pollution studies because it is relatively simple and cost-effective to discriminate between contaminant concentrations and normal background concentrations.
Źródło:
Geological Quarterly; 2016, 60, 1; 67--76
1641-7291
Pojawia się w:
Geological Quarterly
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Contrast-enhanced Magnetic Resonance Imaging of lung cell cultures
Autorzy:
Bober, Zuzanna
Pogoda, Katarzyna
Aebisher, David
Tabarkiewcz, Jacek
Bartusik-Aebisher, Dorota
Powiązania:
https://bibliotekanauki.pl/articles/895529.pdf
Data publikacji:
2020-04-29
Wydawca:
Polskie Towarzystwo Farmaceutyczne
Tematy:
Lung cancer
cell cultures
magnetic resonance imaging
contrast media
Gadolinium
Opis:
Lung cancer is one of the most common types of cancer diagnosed, and the development of methods to image diseased lung tissue by MRI is of utmost importance. Contrast-Enhanced Magnetic Resonance Imaging (CE-MRI) was used to noninvasively evaluate spin-spin relaxation time, T1, of lung cell cultures infused with various clinical gadolinium-based contrast media for imaging. In this study we used a clinical 1.5 Tesla scanner and the contrast agents: Omniscan, MultiHance, Gadovist and ProHance. A significant five-fold reduction of T1 relaxation time was obtained.
Źródło:
Acta Poloniae Pharmaceutica - Drug Research; 2020, 77, 2; 251-258
0001-6837
2353-5288
Pojawia się w:
Acta Poloniae Pharmaceutica - Drug Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Gadolinium on the Microstructure of Magnesium Alloy AZ91
Autorzy:
Rapiejko, Cezary
Mikusek, D.
Just, P.
Pacyniak, T.
Powiązania:
https://bibliotekanauki.pl/articles/1837784.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
metallography
solidification process
magnesium alloys
gadolinium
DTA process
metalografia
proces krzepnięcia
stopy magnezu
gadolin
proces DTA
Opis:
The paper presents the results of research related to the possibility of inoculation of the AZ91 magnesium alloy casted into ceramic moulds by gadolinium. Effects of gadolinium content (0.1–0.6 wt%) on microstructure of the AZ91 alloy under as-cast state were investigated. The influence of the inoculator on the formation of the microstructure investigated by means of the thermal and derivative analysis by analysing the thermal effects arising during the alloy crystallization resulting from the phases formed. The degree of fragmentation of the microstructure of the tested alloys was assessed by means of the light microscopy studies and an image analysis with statistical analysis was performed. Conducted analyses have aimed at examining on the effect of inoculation of the gadolinium on the differences between the grain diameters and average size of each type of grain by way of measuring their perimeters of all phases, preliminary αMg and eutectics αMg+γ(Mg17Al12) in the prepared examined material.
Źródło:
Archives of Foundry Engineering; 2021, 21, 1; 31-36
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Gadolinium on the Microstructure of Magnesium Alloy AZ91
Autorzy:
Rapiejko, C.
Mikusek, D.
Just, P.
Pacyniak, T.
Powiązania:
https://bibliotekanauki.pl/articles/1837850.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
metallography
solidification process
magnesium alloys
gadolinium
DTA process
metalografia
proces krzepnięcia
stopy magnezu
gadolin
proces DTA
Opis:
The paper presents the results of research related to the possibility of inoculation of the AZ91 magnesium alloy casted into ceramic moulds by gadolinium. Effects of gadolinium content (0.1–0.6 wt%) on microstructure of the AZ91 alloy under as-cast state were investigated. The influence of the inoculator on the formation of the microstructure investigated by means of the thermal and derivative analysis by analysing the thermal effects arising during the alloy crystallization resulting from the phases formed. The degree of fragmentation of the microstructure of the tested alloys was assessed by means of the light microscopy studies and an image analysis with statistical analysis was performed. Conducted analyses have aimed at examining on the effect of inoculation of the gadolinium on the differences between the grain diameters and average size of each type of grain by way of measuring their perimeters of all phases, preliminary αMg and eutectics αMg+γ(Mg17Al12) in the prepared examined material.
Źródło:
Archives of Foundry Engineering; 2021, 21, 1; 31-36
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Growth Temperature Effect of Atomic-Layer-Deposited GdOx Films
Autorzy:
Ryu, Sung Yeon
Yun, Hee Ju
Lee, Min Hwan
Choi, Byung Joon
Powiązania:
https://bibliotekanauki.pl/articles/2049285.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
gadolinium oxide
Gd2O3
rare-earth oxide
atomic layer deposition
hydrophobicity
electrical property
Opis:
Gadolinium oxide (Gd2O3) is one of the lanthanide rare-earth oxides, which has been extensively studied due to its versatile functionalities, such as a high permittivity, reactivity with moisture, and ionic conductivity, etc. In this work, GdOx thin film was grown by atomic layer deposition using cyclopentadienyl (Cp)-based Gd precursor and water. As-grown GdOx film was amorphous and had a sub-stoichiometric (x ~ 1.2) composition with a uniform elemental depth profile. ~3 nm-thick GdOx thin film could modify the hydrophilic Si substrate into hydrophobic surface with water wetting angle of 70°. Wetting and electrical test revealed that the growth temperature affects the hydrophobicity and electrical strength of the as-grown GdOx film.
Źródło:
Archives of Metallurgy and Materials; 2021, 66, 3; 755-758
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-11 z 11

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies