Ћир 
Eng 
FFH scientific papers database
1691.
Tjapkin, N; Davidović, M; Colomban, Ph.; Mioč, U
Complex dielectric permittivity, bulk and surface conductivity of 12-tungstophosphoric acid hexahydrate and its dehydrated forms Journal Article
In: Solid State Ionics, vol. 61, no. 1-3, pp. 179-185, 1993.
@article{Tjapkin1993179,
title = {Complex dielectric permittivity, bulk and surface conductivity of 12-tungstophosphoric acid hexahydrate and its dehydrated forms},
author = {N Tjapkin and M Davidović and Ph. Colomban and U Mioč},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0027597124&doi=10.1016%2f0167-2738%2893%2990352-4&partnerID=40&md5=be5dc83983d014a4add5c7c785d19da4},
doi = {10.1016/0167-2738(93)90352-4},
year = {1993},
date = {1993-01-01},
journal = {Solid State Ionics},
volume = {61},
number = {1-3},
pages = {179-185},
abstract = {Impedance measurements on pelletised 12-tungstophosphoric acid hydrates were performed in the frequency range 20 Hz-1 GHz, at temperatures from 20°C to 400°C, in the air of different humidities. Both the dielectric relaxations and conductivity of hexahydrate vary with the amount of water in surface layer. Bulk protonic conductivity of hexahydrate at room temperature was found to be about 3 × 10-11 S cm-1. Interesting behaviour of conductivity of anhydrous samples was observed. © 1993.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Impedance measurements on pelletised 12-tungstophosphoric acid hydrates were performed in the frequency range 20 Hz-1 GHz, at temperatures from 20°C to 400°C, in the air of different humidities. Both the dielectric relaxations and conductivity of hexahydrate vary with the amount of water in surface layer. Bulk protonic conductivity of hexahydrate at room temperature was found to be about 3 × 10-11 S cm-1. Interesting behaviour of conductivity of anhydrous samples was observed. © 1993.
1692.
Fejzo, J; Westler, W M; Markley, J L; Macura, S
In: Journal of the American Chemical Society, vol. 114, no. 4, pp. 1523-1524, 1992.
@article{Fejzo19921523,
title = {Complete Elimination of Spin Diffusion from Selected Resonances in Two-Dimensional Cross-Relaxation Spectra of Macromolecules by a Novel Pulse Sequence (SNOESY)},
author = {J Fejzo and W M Westler and J L Markley and S Macura},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0001308804&doi=10.1021%2fja00030a082&partnerID=40&md5=e6ceb6f6d053790ac903cf424eef23c7},
doi = {10.1021/ja00030a082},
year = {1992},
date = {1992-01-01},
journal = {Journal of the American Chemical Society},
volume = {114},
number = {4},
pages = {1523-1524},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
1693.
Šušić, M V
Spill-over process of hydrogen sorption on palladized alumina, yttria and zeolite 4A Journal Article
In: Journal of Materials Science, vol. 27, no. 14, pp. 3733-3742, 1992.
@article{Šušić19923733,
title = {Spill-over process of hydrogen sorption on palladized alumina, yttria and zeolite 4A},
author = {M V Šušić},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-3743115267&doi=10.1007%2fBF00545449&partnerID=40&md5=f91855df1d680d3e024730781cfd7ed7},
doi = {10.1007/BF00545449},
year = {1992},
date = {1992-01-01},
journal = {Journal of Materials Science},
volume = {27},
number = {14},
pages = {3733-3742},
abstract = {Doping of alumina, yttria and zeolite 4A with small quantities of palladium (down to 0.025%) was done. It was shown that these oxides, which do not normally absorb hydrogen, after the doping acquire a considerable capacity for hydrogen absorption. The sorption of hydrogen is occurring by the spill-over effect from metallic palladium to the oxide. The process is exothermal, taking place in two stages between 60 and 350 °C. Activation energies of the first stage range from 120 to 167 kJ mol-1 and for the second one from 20 to 30 kJ mol-1. After cooling to room temperature in hydrogen flow, the samples are able to absorb considerable quantities of oxygen which reacts exothermally with the previously formed hydride. On next exposition to hydrogen, a vigorous reaction of it with the adsorbed oxygen is taking place already at room temperature. Enthalpies of hydrogen absorption, - ΔH, are of the order of 10 kJ g-1, showing a tendency of increase after repeated exposures to hydrogen. © 1992 Chapman & Hall.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Doping of alumina, yttria and zeolite 4A with small quantities of palladium (down to 0.025%) was done. It was shown that these oxides, which do not normally absorb hydrogen, after the doping acquire a considerable capacity for hydrogen absorption. The sorption of hydrogen is occurring by the spill-over effect from metallic palladium to the oxide. The process is exothermal, taking place in two stages between 60 and 350 °C. Activation energies of the first stage range from 120 to 167 kJ mol-1 and for the second one from 20 to 30 kJ mol-1. After cooling to room temperature in hydrogen flow, the samples are able to absorb considerable quantities of oxygen which reacts exothermally with the previously formed hydride. On next exposition to hydrogen, a vigorous reaction of it with the adsorbed oxygen is taking place already at room temperature. Enthalpies of hydrogen absorption, - ΔH, are of the order of 10 kJ g-1, showing a tendency of increase after repeated exposures to hydrogen. © 1992 Chapman & Hall.
1694.
Tkalčce, E; Šenija, D; Dondur, V; Petranović, N
Influence of Dopants on Nucleation and Growth of High‐Quartz Solid Solution in Lithium Aluminosilicate Glass Journal Article
In: Journal of the American Ceramic Society, vol. 75, no. 7, pp. 1958-1963, 1992.
@article{Tkalčce19921958,
title = {Influence of Dopants on Nucleation and Growth of High‐Quartz Solid Solution in Lithium Aluminosilicate Glass},
author = {E Tkalčce and D Šenija and V Dondur and N Petranović},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-0344407927&doi=10.1111%2fj.1151-2916.1992.tb07223.x&partnerID=40&md5=293c3bd7a093760879483bd7f9f81d53},
doi = {10.1111/j.1151-2916.1992.tb07223.x},
year = {1992},
date = {1992-01-01},
journal = {Journal of the American Ceramic Society},
volume = {75},
number = {7},
pages = {1958-1963},
abstract = {The kinetic parameters of nucleation and crystal growth of high‐quartz solid solution in multicomponent lithium aluminosilicate glasses doped with various transition‐metalions were studied by nonisothermal DTA. The crystallization of glasses nucleated at different temperatures was carried out, and plots of the DTA peak versus the nucleation temperatures were used to determine the maximum nucleation rate temperature. Peak temperature data of nucleated samples at varying heating rates (5–20 K/min) were used to determine the activation energy for crystallization via the JMA equation. The temperature of maximum nucleation rate depends greatly on the doped transition‐ metal ions present. The activation energy for crystallization obtained for undoped glass or glasses doped with Fe2O3 is of the same order as that already published, and the Avrami exponent is consistent with predominantly three‐dimensional crystal growth. The much higher activation energy values for glasses doped with CoO could be a consequence of two crystallization processes proceeding simultaneously. Copyright © 1992, Wiley Blackwell. All rights reserved},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The kinetic parameters of nucleation and crystal growth of high‐quartz solid solution in multicomponent lithium aluminosilicate glasses doped with various transition‐metalions were studied by nonisothermal DTA. The crystallization of glasses nucleated at different temperatures was carried out, and plots of the DTA peak versus the nucleation temperatures were used to determine the maximum nucleation rate temperature. Peak temperature data of nucleated samples at varying heating rates (5–20 K/min) were used to determine the activation energy for crystallization via the JMA equation. The temperature of maximum nucleation rate depends greatly on the doped transition‐ metal ions present. The activation energy for crystallization obtained for undoped glass or glasses doped with Fe2O3 is of the same order as that already published, and the Avrami exponent is consistent with predominantly three‐dimensional crystal growth. The much higher activation energy values for glasses doped with CoO could be a consequence of two crystallization processes proceeding simultaneously. Copyright © 1992, Wiley Blackwell. All rights reserved
1695.
Macura, S; Fejzo, J; Hoogstraten, C G; Westler, W M; Markley, J L
Topological Editing of Cross‐Relaxation Networks Journal Article
In: Israel Journal of Chemistry, vol. 32, no. 2-3, pp. 245-256, 1992.
@article{Macura1992245,
title = {Topological Editing of Cross‐Relaxation Networks},
author = {S Macura and J Fejzo and C G Hoogstraten and W M Westler and J L Markley},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85005665533&doi=10.1002%2fijch.199200031&partnerID=40&md5=70e4fece27d4f026e07a97eea9a1758b},
doi = {10.1002/ijch.199200031},
year = {1992},
date = {1992-01-01},
journal = {Israel Journal of Chemistry},
volume = {32},
number = {2-3},
pages = {245-256},
abstract = {We have used the elements of graph theory to describe NMR cross‐relaxation networks in macromolecules and to analyze different experiments used for topological editing. We propose a new experiment, block decoupled NOESY (B.D. NOESY), that splits the cross‐relaxation network of a macromolecular system into two noninteracting subdomains. Splitting is achieved by arranging for the effective z‐components of the magnetization in one subdomain, as viewed from the other subdomain, to be zero. The B.D. NOESY experiment, in favorable cases, can usefully simplify the analysis of cross‐relaxation spectra by removing certain ambiguities. We demonstrate the method by separating the aromatic resonances from the rest of the cross‐relaxation network of a small globular protein: turkey ovomucoid third domain, Mr 6000. The resulting spectrum provides a clearer picture of cross‐relaxation pathways that involve only aromatic or only aliphatic spins. By comparing the B.D. NOESY spectrum with the normal NOESY spectrum, we were able to identify cross peaks that contain contributions from indirect magnetization transfer (spin diffusion) mediated by the aromatic side chains. In the terminology of graph theory, these experiments decompose topological networks of cross‐relaxation into two subgraphs, the join of which generates the original graph. Copyright © 1992 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We have used the elements of graph theory to describe NMR cross‐relaxation networks in macromolecules and to analyze different experiments used for topological editing. We propose a new experiment, block decoupled NOESY (B.D. NOESY), that splits the cross‐relaxation network of a macromolecular system into two noninteracting subdomains. Splitting is achieved by arranging for the effective z‐components of the magnetization in one subdomain, as viewed from the other subdomain, to be zero. The B.D. NOESY experiment, in favorable cases, can usefully simplify the analysis of cross‐relaxation spectra by removing certain ambiguities. We demonstrate the method by separating the aromatic resonances from the rest of the cross‐relaxation network of a small globular protein: turkey ovomucoid third domain, Mr 6000. The resulting spectrum provides a clearer picture of cross‐relaxation pathways that involve only aromatic or only aliphatic spins. By comparing the B.D. NOESY spectrum with the normal NOESY spectrum, we were able to identify cross peaks that contain contributions from indirect magnetization transfer (spin diffusion) mediated by the aromatic side chains. In the terminology of graph theory, these experiments decompose topological networks of cross‐relaxation into two subgraphs, the join of which generates the original graph. Copyright © 1992 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim
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