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    Tytuł:
    Recycling of Cerium and Lanthanum from Glass Polishing Sludge
    Autorzy:
    Lee, Chi-En Hung
    Lo, Yu-Chien
    Sandagdorj, Nyamdorj
    Gankhuyag, Enkhsaikhan
    Popuri, Srinivasa Rao
    Hung, Chi-En
    Powiązania:
    https://bibliotekanauki.pl/articles/779586.pdf
    Data publikacji:
    2019
    Wydawca:
    Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
    Tematy:
    Cerium
    Lanthanum
    Waste
    Sludge
    Leaching
    Recycling
    Opis:
    To examine the efficiency of La and Ce recycling processes from the sludge, two major methods were used, namely leaching and precipitation. The findings suggest that 12% of La and 24.2% of Ce were contained in the sludge. The sludge was leached in an optimum condition of 6N HCl at a temperature of 70°C with a 3g/50 mL solid/liquid ratio for 3 h to obtain a 100% leaching recovery of La and Ce. After pH adjustment of the obtained La and Ce optimum leaching solution to 6 with NH4OH and a simultaneous addition of H2O2 in a ratio of 1:1, Ce precipitated out with 65.9% recovery. On the other hand, La was not precipitated. The results obtained in this study reveal that leaching and pH adjustment method could be used to recover the valuable REE of La and Ce from glass polishing sludge in order to reach the goals of resource recycling.
    Źródło:
    Polish Journal of Chemical Technology; 2019, 21, 4; 26-30
    1509-8117
    1899-4741
    Pojawia się w:
    Polish Journal of Chemical Technology
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Cobalt-lanthanum catalyst precursors for ammonia synthesis: determination of calcination temperature and storage conditions
    Autorzy:
    Zybert, M.
    Tarka, A.
    Mierzwa, B.
    Raróg-Pilecka, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/778044.pdf
    Data publikacji:
    2017
    Wydawca:
    Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
    Tematy:
    ammonia synthesis
    catalyst precursor
    cobalt
    lanthanum
    thermal analysis
    Opis:
    A thermal decomposition of a cobalt-lanthanum catalyst precursor containing a mixture of cobalt and lanthanum compounds obtained by co-precipitation were studied using thermal analysis coupled with mass spectrometry (TG-MS). Studies revealed that the calcination in air at 500°C is sufficient to transform the obtained cobalt precipitate into Co3 O4 , but it leads to only partial decomposition of lanthanum precipitate. In order to obtain Co/La catalyst precursor containing La2 O3  the calcination in air at the temperature about 800°C is required. However, it is unfavorable from the point of view of textural properties of the catalyst precursor. A strong effect of storage conditions on the phase composition of the studied cobalt-lanthanum catalyst precursor, caused by the formation of lanthanum hydroxide and lanthanum carbonates from La2 O3  when contacting with air, was observed.
    Źródło:
    Polish Journal of Chemical Technology; 2017, 19, 2; 61-66
    1509-8117
    1899-4741
    Pojawia się w:
    Polish Journal of Chemical Technology
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Properties and activity of the cobalt catalysts for NH3 &enspsynthesis obtained by co-precipitation – the effect of lanthanum addition
    Autorzy:
    Zybert, M.
    Karasińska, M.
    Truszkiewicz, E.
    Mierzwa, B.
    Raróg-Pilecka, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/778653.pdf
    Data publikacji:
    2015
    Wydawca:
    Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
    Tematy:
    ammonia synthesis
    cobalt catalyst
    promoter
    lanthanum
    coprecipitation
    Opis:
    In modern research on catalysts for NH3&enspsynthesis a lot of attention is paid to cobalt. In this work the new catalytic systems based on cobalt are presented. Unsupported cobalt catalysts singly promoted (La or Ba) and doubly promoted (La and Ba) were prepared and tested in NH3&enspsynthesis reaction under commercial synthesis conditions. Characterization studies revealed that lanthanum plays a role of a structural promoter, which improves the surface of catalyst precursors and prevents from sintering during calcination. However, lanthanum has a negative effect on the reduction of cobalt oxide, but the addition of barium promoter (Co/La/Ba catalyst) diminishes the negative impact of La. The co-promotion of cobalt with lanthanum and barium results in the increasing of the active phase surface and improvement of its activity in NH3&enspsynthesis.
    Źródło:
    Polish Journal of Chemical Technology; 2015, 17, 1; 138-143
    1509-8117
    1899-4741
    Pojawia się w:
    Polish Journal of Chemical Technology
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Hydroxyapatite Lanthanum Oxide Composites
    Autorzy:
    Bozkurt, Y.
    Pazarlioglu, S.
    Gokce, H.
    Gurler, I.
    Salman, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/1401437.pdf
    Data publikacji:
    2015-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    87.85.jf
    Opis:
    In the present study a commercially synthetic hydroxyapatite powders (CSHAp) were doped with lanthanum oxide (5 and 10 wt.% La₂O₃). The composite powders were well homogenized and pelleted in an uniaxial mould at 350 MPa. Pelleted green bodies were sintered at five different temperatures. Finally, the effect of La₂O₃ amount on the microstructural and mechanical properties of CSHA was investigated. Microstructural properties were detected by X-ray diffraction patterns (XRD) and scanning electron microscope (SEM). Mechanical properties of the sintered samples were determined by the density, hardness and compression strength measurements. Experimental results show that the mechanical properties of HA can be improved by the doping of La₂O₃
    Źródło:
    Acta Physica Polonica A; 2015, 127, 4; 1407-1409
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Lantan i cer w glebach Polski
    Autorzy:
    Kwecko, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/2074972.pdf
    Data publikacji:
    2012
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    lanthanum
    cerium
    REE
    soils
    Polska
    lantan
    cer
    gleby
    Polska
    Opis:
    The paper present basic spatial analysis lanthanum and cerium distribution in Poland soils. Attempted to determine geochemical background and range and intensity of enrichment and anomalies La and Ce content in top (0–0,2 m) and bottom (0,5–2 m) soils. These data are presented in the form two color maps of polygonal with basic statistic information. The text part describes the main areas of enrichment and attempts to indicate the source of these values.
    Źródło:
    Przegląd Geologiczny; 2012, 60, 9; 490--495
    0033-2151
    Pojawia się w:
    Przegląd Geologiczny
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Comparison of Sensitivity of Autotrophic and Heterotrophic Microorganisms to the Pollution of Natural Water with Rare Earth Elements (Lanthanum and Cerium)
    Autorzy:
    Lozhkina, Roza A.
    Olkova, Anna S.
    Koval, Ekaterina V.
    Tomilina, Irina I.
    Sysolyatina, Maria A.
    Powiązania:
    https://bibliotekanauki.pl/articles/2086379.pdf
    Data publikacji:
    2022
    Wydawca:
    Polskie Towarzystwo Inżynierii Ekologicznej
    Tematy:
    rare earth elements
    lanthanum
    cerium
    bioassay
    Nostoc linckia
    Chlorella vulgaris
    Paramecium caudatum
    Escherichia coli
    Opis:
    The purpose of the work was to compare the sensitivity of autotrophic and heterotrophic organisms used in bioassay to lanthanum and cerium under the conditions of a model experiment with aqueous media. Using bioassay methods, the pre-lethal effects of La and Ce in heterotrophic Paramecium caudatum and Escherichia coli, as well as autotrophic Chlorella vulgaris and Nostoc linckia were determined. Model solutions of La2 (SO4)3∙8H2O and Ce2 (SO4)3∙8H2O were tested in the concentration range of 0.1–200 mg/l. As a result, it was shown that heterotrophic organisms are more sensitive to water pollution with La and Ce than autotrophic ones. According to the totality of experiments, cerium turned out to be more toxic than lanthanum. When planning the environmental studies of wastewater or reservoirs polluted with REE, it is recommended to focus on comparative sensitivity of bioassay methods, taking into account the test-functions used: bioassay for chemotaxis of P. caudatum > bioassay for changes in bioluminescence of E. coli (strain M-17) > bioassay for the content of chlorophyll а and intensity of lipid peroxidation in N. linckia > bioassay on the increase in the number of Cl. vulgaris.
    Źródło:
    Journal of Ecological Engineering; 2022, 23, 4; 58--63
    2299-8993
    Pojawia się w:
    Journal of Ecological Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Radioisotope tracer study in an indirectly heated rotary dryer
    Autorzy:
    Pant, H.
    Powiązania:
    https://bibliotekanauki.pl/articles/147094.pdf
    Data publikacji:
    2002
    Wydawca:
    Instytut Chemii i Techniki Jądrowej
    Tematy:
    holdup
    lanthanum-140
    mean residence time
    radioisotope tracer
    residence time distribution
    rotary dryer
    variance
    Opis:
    A radioisotope tracer study was carried-out in a pilot scale indirectly heated rotary dryer to measure residence time distribution (RTD) of sand particles. Lanthanum-140 labeled sand was used as a tracer. Mean residence time (MRT) and variance of the tracer distribution curves were calculated from the measured RTD curves. From the calculated MRTs, solid holdup in the dryer was estimated. The qualitative comparison of the dimensionless variance with the data published in the literature led to the conclusion that the rotary dryer behaves as a plug flow system. The results of the study were used to design a full-scale industrial rotary dryer.
    Źródło:
    Nukleonika; 2002, 47, 4; 173-176
    0029-5922
    1508-5791
    Pojawia się w:
    Nukleonika
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Materiały dla jednowarstwowych ogniw paliwowych
    Materials for single layer fuel cells
    Autorzy:
    Winiarz, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/134696.pdf
    Data publikacji:
    2016
    Wydawca:
    ADVSEO
    Tematy:
    fuel cell
    composite material
    proton conductor
    lanthanum niobate
    scanning electron microscopy
    x-ray diffraction
    Opis:
    A composite material, which may be further applied as a single layer fuel cell, was synthesized using solid state synthesis method. Composite consisted of two components. The first was a nanoceramic proton conductor – calcium doped lanthanum niobate. The second one was a nanoceramic semiconductor oxide composed of lithium, nickel and zinc oxides respectively. Structural and electrical investigations were performed on the received material. Scanning electron microscope images showed that the microstructure on the surface of this material is homogeneous. Energy dispersive X-Ray diffraction confirms that the components of the investigated composite are mixed together in a volume of material allowing to current flow through the percolation threshold. Open circuit voltage was changing during measurement from 0.8V to 0.6V. Moreover, the material did not change its structural properties during the current flow, hence it could be a good candidate to the production of single layer fuel cells.
    Źródło:
    Technical Issues; 2016, 4; 104-109
    2392-3954
    Pojawia się w:
    Technical Issues
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Assessment of a new scintillation crystal (LaBr3) in PET scanners using Monte Carlo method
    Autorzy:
    Karimian, A. E.
    Thompson, Ch. J.
    Powiązania:
    https://bibliotekanauki.pl/articles/146815.pdf
    Data publikacji:
    2008
    Wydawca:
    Instytut Chemii i Techniki Jądrowej
    Tematy:
    PET
    scintillation crystals
    Monte Carlo
    lanthanum bromide
    Opis:
    The main aim of this work is to investigate the use of new lanthanum bromide (LaBr3) in whole body PET (WB-PET) scanners and to compare the obtained results with those for BGO and LSO crystals which are currently used in conventional and dedicated PET systems. Our results show that there is a gain in noise effective count rate (NECR) arising from the reduced scatter and random fractions in a LaBr3 scanner. The spatial resolution of the WB-PET with LaBr3 is slightly worse than the LSO and BGO crystals because of its low density and effective atomic number. But our study showed the increased NECR, excellent energy resolution and low decay time of LaBr3 which promise a significant improvement in WB-PET performances especially for narrow coincidence windows.
    Źródło:
    Nukleonika; 2008, 53, 1; 5-6
    0029-5922
    1508-5791
    Pojawia się w:
    Nukleonika
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    PZT-Type Ceramics Doped with Manganese, Antimony, Lanthanum and Tungsten - Technology and Physical Properties
    Autorzy:
    Bochenek, D.
    Niemiec, P.
    Ćwikiel, E.
    Goryczka, T.
    Powiązania:
    https://bibliotekanauki.pl/articles/353398.pdf
    Data publikacji:
    2020
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    PZT type ceramics
    perovskite type materials
    ferroelectrics
    doped
    Opis:
    The work three ceramic compositions based on PbZr0.49 Ti0.51O3 doped with manganese (Mn), antimony (Sb), lanthanum (La) and tungsten (W) were obtained. The introduction of a set of admixtures was aimed at improving the sinterability of ceramic materials and optimizing its electrophysical parameters. Multi-component materials of the PZT-type with a general formula: Pb(PbZr0.49 Ti0.51)0.94 Mn0.021 Sb0.016 LayWz O3 (where y from 0.008 to 0.012 and z from 0.012 to 0.014) were prepared by the conventional mixed oxide method. After mixing and drying the powder mixtures were calcined in air at 850°C for 4 h, while densification of the powders was carried out by the free sintering method at 1150°C for 2 h. The final steps of technology were grinding, polishing, annealing and putting silver paste electrodes onto both surfaces of the samples for electrical testing. XRD, SEM, EDS, dielectric, ferroelectric, piezoelectric properties and DC electrical conductivity of the obtained ceramic compositions were carried out. X-ray tests of the crystal structure conducted at room temperature have shown that all obtained the PZT-type materials were a single phase (perovskite type) without the presence of a foreign phase. Symmetry of the crystal lattice was identified as space group P4mm. Temperature dielectric studies have shown high values of dielectric permittivity and low dielectric loss. The presented physical properties of ceramic samples based on PZT confirm their predisposition for application in modern microelectronic and micromechatronic applications.
    Źródło:
    Archives of Metallurgy and Materials; 2020, 65, 2; 827-837
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Adsorption of lanthanum(III) and yttrium(III) on kaolinite: kinetics and adsorption isotherms
    Autorzy:
    Zhou, Fang
    Feng, Jian
    Xie, Xiong
    Wu, Baihong
    Liu, Qi
    Wu, Xiaoyan
    Chi, Ruan
    Powiązania:
    https://bibliotekanauki.pl/articles/109951.pdf
    Data publikacji:
    2019
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    adsorption
    kaolinite
    rare earth
    kinetics
    Opis:
    Experimental investigations were carried out using kaolinite to adsorb two rare earth ions, lanthanum ion (La3+) and yttrium ion (Y3+), which will provide some useful information and new insights on the mineralization process and fractionation phenomenon of weathered crust elution-deposited rare earth ores. The results showed that the equilibrium adsorption capacity of Y3+ is greater than La3+ under the same experimental conditions. The adsorption of rare earth ions presents strongly temperature dependent indicating an endothermic adsorption process. The pseudo-first-order kinetic model and the pseudo-second-order kinetic model were applied to discuss the adsorption kinetics. It was found that the adsorption rate of rare earth follows the pseudo-second-order kinetic model among the adsorption temperature range. Furthermore, the adsorption process of rare earth ions on kaolinite followed the Langmuir isotherm model confirmed by the correlation of experimental equilibrium data to standard isotherm model, Langmuir and Freundlich isotherms. The activation energies for the adsorption of La3+ and Y3+ on kaolinite are 28.1903 kJ/mol and 25.4190 kJ/mol, respectively. All kaolinite before and after adsorption were characterized by XRD and SEM-EDX to understand the adsorption mechanism. The obtained results suggested that the adsorption of La3+ and Y3+ on kaolinite is an endothermic and chemisorption process.
    Źródło:
    Physicochemical Problems of Mineral Processing; 2019, 55, 4; 928-939
    1643-1049
    2084-4735
    Pojawia się w:
    Physicochemical Problems of Mineral Processing
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Potencjometryczny sensor chloru
    Potentiometric chlorine sensor
    Autorzy:
    Dziubaniuk, M.
    Janora, S.
    Pasierb, P.
    Rękas, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/155648.pdf
    Data publikacji:
    2010
    Wydawca:
    Stowarzyszenie Inżynierów i Techników Mechaników Polskich
    Tematy:
    sensory potencjometryczne
    ogniwa stałe
    sensor chloru
    tlenochlorek lantanu
    potentiometric gas sensors
    solid cells
    chlorine gas sensor
    lanthanum oxy-chloride
    Opis:
    Do konstrukcji sensora chloru wybrano tlenochlorek lantanu, LaOCl, jako elektrolit stały. Jego warunki preparatyki określono metodą analizy termicznej oraz dyfrakcji promieniowania rentgenowskiego. Mikrostrukturę spieku elektrolitu określono przy użyciu mikroskopii elektronowej. Charakterystykę sensora wyznaczono dla koncentracji chloru w powietrzu w zakresie 0-100 ppm. Skonstruowany sensor pracuje poprawnie i jest stabilny w zakresie temperatur 500 - 800°C. Wyznaczona zależność napięcia źródłowego ogniwa od koncentracji chloru jest zgodna z prawem Nernsta dla n=2.
    A chlorine gas sensor was fabricated with the Cl- ion conducting lanthanum oxy-chloride, LaOCl, a solid electrolyte. Preparation conditions, especially the optimal calcination temperature, were determined by means of the differential thermal analysis (DTA), thermogravimetry (TG) as well as mass spectrometry (MS). According to the x-ray diffraction (XRD) analysis, the product was homogenous and crystallized in tetragonal P4/nmm structure. Scanning electron microscopy (SEM) revealed that it is composed of uniform grains of the 210-260 nm dimension. The sensor manu-facture consisted of several steps. Firstly, the powder of LaOCl was pressed in pellet die (100 MPa) and calcined at 700°C for 2 hours. Then, both sides of polished pellet were covered with Pt paste. It was fired at 1100°C for 2 hours after cooling down the pellet was attached to Al2O3 tube using the ceramic binder to allow the separation of both electrode compartments during the sensor operation. The device was dried and heated at 370°C. The electromotive force (EMF) of the constructed cell was measured asa function of temperature (400- 800°C), Cl2 concentration in air (0-100 ppm) at sensing electrode and time. Air with constant concen-tration of chlorine (100 ppm) gas atmosphere was kept at reference electrode. The sensor exhibited reliable, stable and reproducible signal at operation temperature between 500 - 800°C. The deter-mined EMF vs. logp(Cl2) dependence may be described by the Nernst law for n= 2.
    Źródło:
    Pomiary Automatyka Kontrola; 2010, R. 56, nr 6, 6; 525-528
    0032-4140
    Pojawia się w:
    Pomiary Automatyka Kontrola
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Nickel/Zinc ratio and lanthanum substitution effect on structural and magnetic properties of nickel zinc ferrites
    Autorzy:
    Jančárik, V.
    Šoka, M.
    Ušáková, M.
    Harťanský, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/1053078.pdf
    Data publikacji:
    2017-04
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.50.Gg
    75.30.Cr
    61.05.C-
    Opis:
    Improvement of NiZn ferrites properties by means on Ni/Zn content ratio modification and by partial substitution of Fe³⁺ ions by La³⁺ ions is presented. Ni_{x}Zn_{1-x}Fe₂O₄ and Ni_{x}Zn_{1-x}La_{0.02}Fe_{1.98}O₄ samples of small particles were prepared by self-propagated combustion method. X-ray spectroscopy was used for structural analysis, temperature dependence of magnetic susceptibility was used for evaluation of chemical and phase composition. Analysis showed that pure spinel structure without secondary phase caused by La ions for all values of Ni/Zn content was present. Noticeable growth of the magnetic susceptibility at room temperature was observed with rising of Zn²⁺ ions content.
    Źródło:
    Acta Physica Polonica A; 2017, 131, 4; 693-695
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Synthesis, Spectral Characterization and Biological Studies of Lanthanum(III) Complexes with 3-Substituted-4-Amino-5-Mercapo-1,4-Triazoles Schiff Bases
    Autorzy:
    Yadawe, M. S.
    Unki, S. N.
    Patil, S. A.
    Powiązania:
    https://bibliotekanauki.pl/articles/411978.pdf
    Data publikacji:
    2013
    Wydawca:
    Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
    Tematy:
    Schiff
    antibacterial
    antifungal
    Opis:
    Some lanthanum(III) complexes have been synthesized by reacting lanthanum(III) metal salt with Schiff bases derived from 3-substituted-4-amino-5-mercapto-1,2,4-triazole and glyoxal/ biacetyl/ benzyl. All these complexes are not soluble in common organic solvents. However sparingly soluble in DMF and DMSO. The chemical analysis of the complexes confirmed to the stoichiometry of the type La(III)LNO3•H2O. La(III)LCl•H2O and La(III)LNCS•H2O respectively. The chelation of the complexes has been proposed in the light of analytical, spectral studies. The measured molar conductance values indicate that, the complexes are non-electrolytes. The Schiff bases and their complexes have been screened for their antibacterial and antifungal activities. The results of these studies show the metal complexes to be more antibacterial and antifungal as compared to the uncomplexed coumarins. lanthanum(III) complexes.
    Źródło:
    International Letters of Chemistry, Physics and Astronomy; 2013, 12; 94-104
    2299-3843
    Pojawia się w:
    International Letters of Chemistry, Physics and Astronomy
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Determination of lanthanum(III) and europium(III) – lactate interaction constants by capillary electrophoresis for environmental applications
    Autorzy:
    Bortolus, S.
    Varenne, A.
    Draye, M.
    Gareil, P.
    Czerwiński, K.
    Cote, G.
    Powiązania:
    https://bibliotekanauki.pl/articles/347001.pdf
    Data publikacji:
    2003
    Wydawca:
    Politechnika Bydgoska im. Jana i Jędrzeja Śniadeckich. Wydział Technologii i Inżynierii Chemicznej
    Tematy:
    lanthanides(III)
    lactate
    separation
    interaction constants
    capillary electrophoresis
    Opis:
    In the present work, we investigated the ability of electrophoresis to determine the stability constant of the complex formed between lactate ions (a simple model of natural organic matter), and lanthanum (III) and europium (III), two model metal cations of actinides. The effect of lactate on lanthanide’s effective mobility is studied, and conditional metal ion-ligand interaction constants are determined on the basis of the variation in the effective mobilities (log βn = 2.23 for lanthanum (III) and 2.39 for europium (III), at 25°C and I=0.015 M). The originality of this contribution lies in the fact that we have chosen to detect the metal ion instead of the ligand by an indirect UV-visible detection and using a chromophoric compound (creatinine).
    Źródło:
    Ars Separatoria Acta; 2003, 2; 29-35
    1731-6340
    Pojawia się w:
    Ars Separatoria Acta
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Behavioral and Lethal Effects of La Salt and a Mixture of Cu and La Salt on Daphnia magna Straus
    Autorzy:
    Olkova, Anna Sergeewna
    Sysolyatina, Maria
    Powiązania:
    https://bibliotekanauki.pl/articles/2105282.pdf
    Data publikacji:
    2022
    Wydawca:
    Polskie Towarzystwo Inżynierii Ekologicznej
    Tematy:
    lanthanum
    copper
    bioassay
    Daphnia magna
    motor activity
    joint effect
    synergism
    potentiation
    Opis:
    The study of joint effects of REE and HM is relevant, since they are often satellite deposits, their areas of application are similar, and an increase in concentrations of elements of these groups in the areas that are not places of their extraction and enrichment is proven. The purpose of this work was to find out the pre-lethal and lethal effects of La, Cu and their equimolar mixtures in tests for Daphnia magna Straus. Bioassays of artificially polluted natural waters, initially free of toxic elements, was carried out. In bioassays on the mortality of D. magna in the space of 96 hours it was found that acute toxicity of copper sulfate solutions is observed at the calculated concentration of Cu2+ 0.1 mg/L (0.0016 mmol/L), and the acute toxicity of lanthanum sulfate is when the dose of La3+ is equal to 50 mg/L (0.36 mmol/L). In the solutions comprising mixtures of Cu and La salts (1:1 calculated using metals), the concentrations of which are equimolar to the investigated solutions of copper sulfate, the mortality of D. magna begins in the solution containing 10 times less toxic elements. It was found that 25% of individuals died in the variant “0.00016 mmol/L”, the mortality of 100% of individuals was at the total metal concentration of 0.0008 mmol/L. The solutions containing La (0.072–0.72 mmol/L) and Cu (0.00016–0.0016 mmol/L) naturally inhibit the motor activity of D. magna by 1.3–5.3 times and 1.2–1.9 times in 1 hour and 1.7–2.8 and 1.4–2.2 times in 24 hours, respectively. The solutions containing mixtures of Cu and La salts inhibited the motor activity of D. magna in the same way as copper sulfate solutions with the Cu2+ concentrations equimolar “Cu2+ + La3+”. Therefore, when testing the solutions with the same molar concentrations of Cu2+ and the mixture of “Cu2+ + La3+” it was shown that La potentiates the pre-lethal effect of Cu to the level of individual effects of Cu. The additions of La salt to the solutions containing pre-lethal doses of Cu lead to lethal effects of such mixtures for D. magna.
    Źródło:
    Journal of Ecological Engineering; 2022, 23, 6; 245--252
    2299-8993
    Pojawia się w:
    Journal of Ecological Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Low-Frequency Mechanical Spectroscopy of Lanthanum Cobaltite Based Mixed Conducting Oxides
    Autorzy:
    Wu, X. S.
    Cao, J. F.
    Chen, Z. J.
    Liu, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/355599.pdf
    Data publikacji:
    2016
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    mixed conducting oxides
    mechanical properties
    domain structure
    phase transition
    mechanical spectroscopy
    internal friction
    Opis:
    The low-frequency mechanical spectra of lanthanum cobaltite based mixed conducting oxides have been measured using a computer-controlled inverted torsion pendulum. The results indicate that the internal friction spectra and shear modulus depend on the Sr doping contents (x). For undoped samples, no internal friction peak is observed. However, for La0.8Sr0.2CoO3-δ, three internal friction peaks (P2, P3 and P4) are observed. In addition to these peaks, two more peaks (P0 and P1) are observed in La0.6Sr0.4CoO3‒δ. The P0 and P1 peaks show characteristics of a phase transition, while the P2, P3 and P4 peaks are of relaxation-type. Our analysis suggests that the P0 peak is due to a phase separation and the P1 peak is related to the ferromagnetic–paramagnetic phase transition. The P2, P3 and P4 peaks are associated with the motion of domain walls. The formation of this kind of domain structure is a consequence of a transformation from the paraelastic cubic phase to the ferroelastic rhombohedral phase. With partial substitution of Fe for Co, only one peak is observed, which is discussed as a result of different microstructure.
    Źródło:
    Archives of Metallurgy and Materials; 2016, 61, 3; 1733-1738
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Influence of Lanthanum Dopant on the Structure and Electric Properties of BaBi2Nb2O9 Ceramics
    Autorzy:
    Adamczyk-Habrajska, M.
    Goryczka, T.
    Szalbot, D.
    Dzik, J.
    Rerak, M.
    Bochenek, D.
    Powiązania:
    https://bibliotekanauki.pl/articles/353535.pdf
    Data publikacji:
    2020
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    ferroelectric relaxor
    ceramics
    impedance spectroscopy
    Opis:
    The paper reports the consequences of lanthanum modifications of barium bismuth niobiate (BaBi2 Nb2 O9) ceramics. The discussed materials were prepared by solid state synthesis and a one-step sintering process. The investigations are focused on dielectric aspects of the modification. The presented results reveal that the trivalent lanthanum ions incorporate twovalent barium ions, which is connected with the creation of A-site cationic vacancies as well as oxygen vacancies. Such a scenario results in significant decreasing in grain boundaries resistivity. The activation energy of grain boundaries conductivity is significantly reduced in the case of lanthanum admixture.
    Źródło:
    Archives of Metallurgy and Materials; 2020, 65, 1; 207-214
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Investigation of Heterostructure Formed from Hole- and Electron-Doped Lanthanum Manganites
    Autorzy:
    Vengalis, B.
    Rosa, A. M.
    Devenson, J.
    Šliužienė, K.
    Lisauskas, V.
    Oginskis, A.
    Anisimovas, F.
    Pyragas, V.
    Powiązania:
    https://bibliotekanauki.pl/articles/2041760.pdf
    Data publikacji:
    2005-02
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    73.40.Cg
    73.40.Lg
    75.50.Dd
    Opis:
    High crystalline quality films of n-La$\text{}_{2}\text{}_{/}\text{}_{3}$ Ce$\text{}_{1}\text{}_{/}\text{}_{3}$ MnO$\text{}_{3}$, p-La$\text{}_{2}\text{}_{/}\text{}_{3}$ Ca$\text{}_{1}\text{}_{/}\text{}_{3}$ MnO$\text{}_{3}$ and related p-n diode structures were grown heteroepitaxially on lattice-matched SrTiO$\text{}_{3}$(100) substrates by dc magnetron sputtering and pulsed laser deposition. The La$\text{}_{2}\text{}_{/}\text{}_{3}$ Ce$\text{}_{1}\text{}_{/}\text{}_{3}$ Mn O$\text{}_{3}$/La$\text{}_{2}\text{}_{/}\text{}_{3}$ Ca$\text{}_{1}\text{}_{/}\text{}_{3}$ MnO$\text{}_{3}$ bilayer was patterned into a strip-like geometry to investigate electrical properties of the interface. Significant magnetoresistance values and nonlinear current-voltage characteristics were indicated for the interface of the p-n diode heterostructure.
    Źródło:
    Acta Physica Polonica A; 2005, 107, 2; 290-293
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Dual Pore Cathode Materials for Solid Oxide Fuel Cells
    Autorzy:
    Mosiałek, M.
    Zimowska, M.
    Kharitonov, D.
    Górski, M.
    Krzan, M.
    Komenda, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/354965.pdf
    Data publikacji:
    2020
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    solid oxide fuel cell
    yttrium iron cobaltite
    lanthanum strontium cobalt ferrite
    composite cathode
    electrochemical impedance spectroscopy
    Opis:
    In this work, we developed the lanthanum strontium cobalt ferrite and it’s composite with yttrium iron cobaltite (mass ratio of 1:1) cathodes as a thin layer on Ce0.8Sm0.2O1.9 electrolyte. Two kinds of electrode pastes were prepared, with and without 6 mm polystyrene beads as an additional pore former. The performance of cathode materials was investigated by electrochemical impedance spectroscopy as a function of electrode morphology, oxygen partial pressure, potential, and temperature. The polarization resistance of the more porous electrodes was lower than those electrodes prepared without additional pore former in the whole potential range at 800°C, slightly lower at 700°C and 600°C. The addition of yttrium iron cobaltite decreased the performance of both types of cathodes. The lower polarization resistance of porous cathodes is due to the facilitated gas diffusion through their structure.
    Źródło:
    Archives of Metallurgy and Materials; 2020, 65, 3; 1217-1221
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Mesoscopic Ordering Effects in Single-Crystalline Thin Films of Lanthanum Manganites
    Autorzy:
    Samoilenko, Z. A.
    Okunev, V. D.
    Pushenko, E. I.
    Abal'oshev, A.
    Baran, M.
    Gierłowski, P.
    Lewandowski, S. J.
    Szymczak, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/2037100.pdf
    Data publikacji:
    2004
    Wydawca:
    Polska Akademia Nauk. Instytut Fizyki PAN
    Tematy:
    75.30.Kz
    75.47.Lx
    61.50.Ks
    Opis:
    We have investigated thin films of lanthanum manganites epitaxially grown by pulsed laser deposition on single-crystalline substrates. X-ray diffraction studies show that the characteristic feature of the investigated films is a superposition of fractions with long range atomic order in the basic single-crystalline matrix, and mesoscopic order in the clusterized structure encompassing the Mn-O layers. A detailed analysis of diffusive scattering shows that the size of metallic clusters and their volume concentration in the dielectric matrix varies. In the case of a small size and concentration, the metallic clusters in low temperature behave as quantum dots and their presence leads to a tunneling mechanism of conductivity with characteristic R(T)= const. In the case of large cluster size, the discrete energy levels become smeared. It appears also that the optical, transport, and magnetic properties of the investigated films depend critically on the distribution of Mn$\text{}^{2+}$, Mn$\text{}^{3+}$, and Mn$\text{}^{4+}$ ions in the clusters.
    Źródło:
    Acta Physica Polonica A; 2004, 105, 1-2; 93-98
    0587-4246
    1898-794X
    Pojawia się w:
    Acta Physica Polonica A
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Influence of Co2 on the Catalytic Performance Of La2O3/CeO2 and CaO/CeO2 Catalysts in the Oxidative Coupling of Methane
    Autorzy:
    Litawa, B.
    Michorczyk, P.
    Ogonowski, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/779348.pdf
    Data publikacji:
    2013
    Wydawca:
    Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
    Tematy:
    CO2 effect
    OCM
    lanthanum oxide
    calcium oxide
    ethylene
    Opis:
    In this work the La2O3/CeO2 (33 mol % of La) and CaO/CeO2 (33 mol % of Ca) catalysts were prepared by the impregnation method and characterized by XRD and CO2-TPD. The catalytic properties of the catalysts were tested in the OCM process at 1073 K using the methane/oxygen mixture of the mole ratio 3.7 or 2.5 additionally containing CO2 and helium balance. It was found that in the presence of both catalysts an addition of CO2 enhances the selectivity to the ethylene and ethane and it does not have Any negative infl uence on methane conversion. In the case of the CaO/CeO2 catalyst the promoting effect of CO2 was the highest. When the partial pressure of CO2 equals to 39 kPa the increase in selectivity from 36 to 41% was noted while the conversion of methane equal to 19.4-19.7 %.
    Źródło:
    Polish Journal of Chemical Technology; 2013, 15, 1; 22-26
    1509-8117
    1899-4741
    Pojawia się w:
    Polish Journal of Chemical Technology
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Synthesis, microstructure and the crystalline structure of the barium titanate ceramics doped with lanthanum
    Synteza, mikrostruktura i struktura krystaliczna ceramicznego tytanianu baru domieszkowanego lantanem
    Autorzy:
    Wodecka-Duś, B.
    Plońska, M.
    Czekaj, D.
    Powiązania:
    https://bibliotekanauki.pl/articles/355838.pdf
    Data publikacji:
    2013
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    Ba1-xLaxTi1-x/4O3 ceramics
    La3+ doping
    microstructure
    perovskites
    ceramika Ba1-xLaxTi1-x/4O3
    ceramika BLT
    stężenie La3+
    mikrostruktura
    perowskity
    Opis:
    In the present study BaTiO3 and Ba1-xLaxTiO3 (0.1-0.4mol.% La) ceramic powders were synthesized by the conventional mixed oxide method (MOM). The characterization of the ceramic powders was carried out using a simultaneous thermal analysis (STA), with a combined DTA/TG/DTG system (Netzsch STA409). The results of thermal analysis allowed to determine the optimal temperature of synthesis. Microstructure was investigated by scanning electron microscopy (SEM), crystalline structure was studied by X-ray diffraction method (XRD). The EDS investigations showed that samples exhibited conservation of stoichiometry according to the chemical composition formula. The X-ray diffraction analysis confirmed formation of the desired crystalline structure both pure and La3+-doped BaTiO3 ceramics exhibiting a perovskite-type structure ABO3 with tetragonal symmetry P4 mm.
    W prezentowanej pracy przeprowadzono badania ceramiki BaTiO3 and Ba1-xLaxTiO3 (BLT) dla koncentracji z prze- działu 0,001< x <0,004 (0,l-0,4mol.% La). Ceramikę BLT wytworzono z mieszaniny prostych tlenków La2O3, TiO2 i BaCO3 (wszystkie o czystości 99,9+%, Aldrich Chemical Co.) Proszki ceramiczne otrzymano metodą konwencjonalną w stanie stałym (metodą MOM) i poddano badaniu mikrostruktury i struktury krystalicznej. Mieszaniny proszków poddano analizie termicznej. Wyniki analizy termicznej określiły optymalną temperaturę syntezy oraz procesy zachodzące podczas ogrzewania proszków. Następnie proszki formowano w dyski pod ciśnieniem 300MPa w matrycach ze stali nierdzewnej o średnicy 10 mm. Syntezę przeprowadzono w Ts =950°C t =2 godz. Ostatnim krokiem technologii było bezciśnieniowe spiekanie metodą swobodnego spiekania w T = 1350°C przez t =2 godziny. Morfologię otrzymanego materiału ceramicznego obserwowano metodą skaningowej mikroskopii elektronowej. Ceramikę BLT badano również pod względem składu chemicznego metodą EDS. Analizę strukturalną przeprowadzono metodą dyfrakcji rentgenowskiej. Badania mikrostruktury i struktury krystalicznej ceramiki przeprowadzono w temperaturze pokojowej. Badania EDS potwierdziły zachowanie stechiometrii otrzymanych próbek według wzoru chemicznego. Rentgenowska analiza dyfrakcyjna potwierdziły wytworzenie pożądanej struktury krystalicznej zarówno czystej ceramiki BaTiO3 jak i z domieszką La3+. Otrzymana ceramika wykazuje strukturę typu perowskitu ABO3 o symetrii tetragonalnej P4 mm. Stwierdzono, że wraz ze wzrostem stężenia La3+ w BaTiO3 następuje zmniejszenie wielkości ziarn krystalicznych, zmniejszenie średniego wymiaru krystalitów, zmniejszenie objętości komórki elementarnej oraz wzrost obliczonej rentgenowskiej gęstości.
    Źródło:
    Archives of Metallurgy and Materials; 2013, 58, 4; 1305-1308
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Ba0.5Sr0.5Co0.8Fe0.2O3-σ and La0.6Sr0.4Co0.8Fe0.2O3-σ composite cathode for solid oxide fuel cell
    Autorzy:
    Mosiałek, M.
    Kędra, A.
    Krzan, M.
    Bielańska, E.
    Tatko, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/355878.pdf
    Data publikacji:
    2016
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    barium strontium cobalt ferrite
    lanthanum strontium cobalt ferrite
    solid oxide fuel cell
    oxygen reduction reaction
    electrochemical impedance spectroscopy
    Opis:
    Composite cathodes contain Ba0.5Sr0.5Co0.8Fe0.2O3-σ and La0.6Sr0.4Co0.8Fe0.2O3-σ were tested in different configuration for achieving cathode of area specific resistance lower than Ba0.5Sr0.5Co0.8Fe0.2O3-σ and La0.6Sr0.4Co0.8Fe0.2O3-σ cathodes. Electrodes were screen printed on samaria-doped ceria electrolyte half-discs and tested in the three electrode setup by the electrochemical impedance spectroscopy. Microstructure was observed by scanning electron microscopy. The lowest area specific resistance 0.46 and 2.77 Ω cm-2 at 700 °C and 600 °C respectively revealed composite cathode contain Ba0.5Sr0.5Co0.8Fe0.2O3-σ and La0.6Sr0.4Co0.8Fe0.2O3-σ in 1:1 weight ratio. The area specific resistance of this cathode is characterized by the lowest activation energy among tested cathodes.
    Źródło:
    Archives of Metallurgy and Materials; 2016, 61, 3; 1483-1488
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Złote glony (algi-zabójcy) jako zagrożenie dla gospodarki i przyrody Polski
    Golden algae (“killer algae”) as a threat to Polands economy and nature
    Autorzy:
    Kapler, Adam
    Powiązania:
    https://bibliotekanauki.pl/articles/29433452.pdf
    Data publikacji:
    2024
    Wydawca:
    Mazowieckie Biuro Planowania Regionalnego w Warszawie
    Tematy:
    złote glony
    Prymnesium parvum
    prymnezyny
    zakwit
    HAB
    klęska ekologiczna
    Odra
    starorzecza
    Phoslock
    La
    biostabilizator jęczmienny
    CuSo4
    H2O2
    PIX111
    golden algae
    prymnesins
    algal bloom
    HAB (harmful algal bloom)
    ecological disaster
    Oder River
    Gliwice Canal
    oxbow lakes
    Lanthanum
    coagulants
    barley biostabilizer
    Opis:
    Bezprecedensowy zakwit „złotych alg” Prymnesium parvum w Odrze w 2022 r. był najgorszą klęską ekologiczną w Polsce i Niemczech od dekad. W 2023 r. udało się powstrzymać przenikanie „glonów-zabójców” z Kanału Gliwickiego, jak również zbiorników Czernica i Januszkowice do głównego nurtu Odry. Artykuł przedstawia aktualny stan wiedzy o tej katastrofie oraz wnioski z przeprowadzonych w Polsce, pionierskich testów metod wygaszania zakwitów w wodach płynących. Ponadto w niniejszej pracy zebrano i przedstawiono zagraniczne sposoby zwalczania „złotych alg” w stawach rybnych, na obszarach cennych dla przyrody, żeglarstwa i wędkarstwa, jak również restytucji fauny (w tym małży skójkowatych, istotnych tak dla gospodarki, jak dla ochrony przyrody) po masowym zakwicie P. parvum.
    The unprecedented bloom of “golden algae” Prymnesium parvum in the Oder River in 2022 was the worst ecological disaster in Poland and Germany in decades. In 2023, the penetration of those “killer algae” from the Gliwice Canal, as well as the Czernica and Januszkowice reservoirs into the main stream of the Oder River has been stopped by the Polish Waters. The article presents the current state of knowledge about this catastrophe and draws conclusions from pioneering tests conducted in Poland on methods to mitigate blooms in flowing waters (in the Gliwice Canal). Additionally, this work compiles and presents foreign methods of combating “golden algae” in fish ponds, in areas valuable for nature, sailing and fishing, as well as fauna restitution (including Unionidae mussels, significant for both the economy and for nature protection) following a mass bloom of P. parvum.
    Źródło:
    MAZOWSZE Studia Regionalne; 2024, 48; 37-61
    1689-4774
    Pojawia się w:
    MAZOWSZE Studia Regionalne
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
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