| Records |
| Author |
Covaci, L.; Berciu, M. |
| Title |
Holstein polaron: The effect of coupling to multiple-phonon modes |
Type |
A1 Journal article |
| Year |
2007 |
Publication |
Epl |
Abbreviated Journal |
Epl-Europhys Lett |
| Volume |
80 |
Issue |
6 |
Pages |
67001 |
Keywords  |
A1 Journal article |
| Abstract |
We investigate the effects of coupling to multiple-phonon modes on the properties of a Holstein polaron. To this end, we generalize the Momentum Average approximations MA((0)) and MA((1)) to deal with multiple-phonon modes. As for a single-phonon mode, these approximations are found to be numerically very efficient. They become exact for very weak or very strong couplings, and are highly accurate in the intermediate regimes, e.g. the spectral weights obey exactly the first six, respectively eight, sum rules. Our results show that the effect on ground-state properties is cumulative in nature. As a result, if the effective coupling to one mode is much larger than to all the others, this mode effectively determines the ground-state properties. However, even very weak coupling to a second phonon mode has important non-perturbational effects on the higher-energy spectrum, in particular on the dispersion and the phonon statistics of the polaron band. This has important consequences on the analysis and interpretation of data for real materials. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000251648300016 |
Publication Date |
2007-11-30 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0295-5075 |
ISBN |
|
Additional Links |
|
| Impact Factor |
1.957 |
Times cited |
9 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 1.957; 2007 IF: 2.206 |
| Call Number |
UA @ lucian @ |
Serial |
4431 |
| Permanent link to this record |
| |
|
| |
| Author |
Marchand, D.; Covaci, L.; Berciu, M.; Franz, M. |
| Title |
Giant proximity effect in a phase-fluctuating superconductor |
Type |
A1 Journal article |
| Year |
2008 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys Rev Lett |
| Volume |
101 |
Issue |
9 |
Pages |
097004 |
| Keywords |
A1 Journal article |
| Abstract |
When a tunneling barrier between two superconductors is formed by a normal material that would be a superconductor in the absence of phase fluctuations, the resulting Josephson effect can undergo an enormous enhancement. We establish this novel proximity effect by a general argument as well as a numerical simulation and argue that it may underlie recent experimental observations of the giant proximity effect between two cuprate superconductors separated by a barrier made of the same material rendered normal by severe underdoping. |
| Address |
Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, Canada V6T 1Z1 |
| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
|
Editor |
|
| Language |
English |
Wos |
000259195800055 |
Publication Date |
2008-08-28 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0031-9007 |
ISBN |
|
Additional Links |
|
| Impact Factor |
8.462 |
Times cited |
17 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 8.462; 2008 IF: 7.180 |
| Call Number |
UA @ lucian @ |
Serial |
4433 |
| Permanent link to this record |
| |
|
| |
| Author |
Covaci, L.; Berciu, M. |
| Title |
Polaron formation in the presence of Rashba spin-orbit coupling: implications for spintronics |
Type |
A1 Journal article |
| Year |
2009 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys Rev Lett |
| Volume |
102 |
Issue |
18 |
Pages |
186403 |
| Keywords |
A1 Journal article |
| Abstract |
We study the effects of the Rashba spin-orbit coupling on polaron formation, using a suitable generalization of the momentum average approximation. While previous work on a parabolic band model found that spin-orbit coupling increases the effective mass, we show that the opposite holds for a tight-binding model, unless both the spin-orbit and the electron-phonon couplings are weak. It is thus possible to lower the effective mass of the polaron by increasing the spin-orbit coupling. We also show that when the spin-orbit coupling is large as compared to the phonon energy, the polaron retains only one of the spin-polarized bands in its coherent spectrum. This has major implications for the propagation of spin-polarized currents in such materials, and thus for spintronic applications. |
| Address |
Department of Physics, University of British Columbia, Vancouver, British Columbia, Canada, V6T 1Z1 |
| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
|
Editor |
|
| Language |
English |
Wos |
000265948600049 |
Publication Date |
2009-05-08 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0031-9007 |
ISBN |
|
Additional Links |
|
| Impact Factor |
8.462 |
Times cited |
25 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 8.462; 2009 IF: 7.328 |
| Call Number |
UA @ lucian @ |
Serial |
4434 |
| Permanent link to this record |
| |
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| |
| Author |
Goemans, M.; Clarysse, P.; Joannès, J.; de Clercq, P.; Lenaerts, S.; Matthys, K.; Boels, K. |
| Title |
Catalytic Nox reduction with simultaneous dioxin and furan oxidation |
Type |
A1 Journal article |
| Year |
2004 |
Publication |
Chemosphere |
Abbreviated Journal |
Chemosphere |
| Volume |
54 |
Issue |
9 |
Pages |
1357-1365 |
| Keywords |
A1 Journal article |
| Abstract |
The engineering, construction, performance and running costs of a catalytic flue gas cleaning component in the low dust area of a municipal waste incinerator is discussed. For this purpose, the case study of a Flemish incineration plant is presented, covering the history, the design procedure of the catalyst, relevant process data and the financial aspects. A reliable PCDD/F-destruction by means of oxidation by the catalyst to typical values of 0.001 ng TEQ/Nm3 has been demonstrated. At the same time, NOx− and CO-emissions are reduced by 90% and 20% to about 50 mg/Nm3 and below 10 mg/Nm3, respectively. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
|
| Language |
|
Wos |
000188293500011 |
Publication Date |
2003-12-02 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0045-6535; 1879-1298 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles; WoS full record; WoS citing articles |
| Impact Factor |
4.208 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 4.208; 2004 IF: 2.359 |
| Call Number |
UA @ admin @ c:irua:82011 |
Serial |
5931 |
| Permanent link to this record |
| |
|
| |
| Author |
Goemans, M.; Clarysse, P.; Joannès, J.; de Clercq, P.; Lenaerts, S.; Matthys, K.; Boels, K. |
| Title |
Catalytic Nox reduction with simultaneous dioxin and furan oxidation |
Type |
A1 Journal article |
| Year |
2003 |
Publication |
Chemosphere |
Abbreviated Journal |
Chemosphere |
| Volume |
50 |
Issue |
4 |
Pages |
489-497 |
| Keywords |
A1 Journal article |
| Abstract |
The engineering, construction, performance and running costs of a catalytic flue gas cleaning component in the low dust area of a municipal waste incinerator is discussed. For this purpose, the case study of a Flemish incineration plant is presented, covering the history, the design procedure of the catalyst, relevant process data and the financial aspects. A reliable PCDD/F-destruction by means of oxidation by the catalyst to typical values of 0.001 ng TEQ/N m3 has been demonstrated. At the same time, NOx- and CO-emissions are reduced by 90% and 20% to about 50 mg/N m3 and below 10 mg/N m3, respectively. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
|
| Language |
|
Wos |
000180078200004 |
Publication Date |
2002-12-10 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0045-6535; 1879-1298 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles; WoS full record; WoS citing articles |
| Impact Factor |
4.208 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 4.208; 2003 IF: 1.904 |
| Call Number |
UA @ admin @ c:irua:82010 |
Serial |
5932 |
| Permanent link to this record |
| |
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| |
| Author |
Delabie, L.; Honoré, M.; Lenaerts, S.; Huyberechts, G.; Roggen, J.; Maes, G. |
| Title |
The effect of sintering and Pd-doping on the conversion of CO to CO2 on SnO2 gas sensor materials |
Type |
A1 Journal article |
| Year |
1997 |
Publication |
Sensors And Actuators B-Chemical |
Abbreviated Journal |
Sensor Actuat B-Chem |
| Volume |
44 |
Issue |
|
Pages |
446-451 |
| Keywords |
A1 Journal article |
| Abstract |
The principal aim of this work is to study the effect of the processes of sintering and Pd doping of SnO2 gas sensor materials on the conversion of CO to CO2. For this purpose, the gas phase above screen printed sensor material is investigated using FTIR spectroscopy, while surface area, porosity and particle size measurements are performed on the SnO2 powders. During sintering, larger agglomerates of primary particles are formed, which results in a larger conversion degree of CO. The effect of Pd doping of the tin dioxide film on the CO conversion is more pronounced. The transformation of CO starts at a lower temperature and the conversion degree increases remarkably. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
|
| Language |
|
Wos |
000071717900035 |
Publication Date |
2002-07-25 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0925-4005 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles; WoS full record; WoS citing articles |
| Impact Factor |
5.401 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 5.401; 1997 IF: 0.858 |
| Call Number |
UA @ admin @ c:irua:82017 |
Serial |
5947 |
| Permanent link to this record |
| |
|
| |
| Author |
Lenaerts, S.; Honoré, M.; Huyberechts, G.; Roggen, J.; Maes, G. |
| Title |
In situ infrared and electrical characterization of tin dioxide gas sensors in nitrogen/oxygen mixtures at temperatures up to 720 K |
Type |
A1 Journal article |
| Year |
1994 |
Publication |
Sensors and actuators : B : chemical |
Abbreviated Journal |
|
| Volume |
19 |
Issue |
|
Pages |
478-482 |
| Keywords |
A1 Journal article |
| Abstract |
FT-IR spectroscopy and impedance measurements of tin dioxide sensor materials at working temperatures up to 450 °C in atmospheres with varying O2/N2 ratio are used as an in situ probe to study the interactions at the surface of the semiconducting oxide. Every diminution in the oxygen content above the sample induces a broad IR absorption band (X-band) between 2300700 cm−1 with a few small peaks in the 1400850 cm−1 region of the spectrum superimposed on it. The X-band results from the enchanced electron concentration in the bulk of the tin dioxide domain. The fine structure is due to the absorption of several kinds of surface oxygen species associated vibration modes. The porous tin dioxide consists of domains were the outward shell is depleted of electrons by the formation of adsorbed O− species on oxygen surface sites, SO(O− species. In our proposed model for the impedance data this gives rise to a parallel RpCp circuit for the domain boundary characteristics and to an Rs parameter for the intradomain resistance. The evolution of these IR and impedance spectroscopic effects with temperature and oxygen content is used to set up, to confirm and refine a physicochemical operation model of tin dioxide gas sensor. This model consists of a sensitizing reaction sequence in the presence of oxygen and a gas-detection reaction sequence when a reducing gas is present. Based on this model, the principal disadvantages of this type of gas sensor become clear. Every factor that influences the concentration of SO(O−) species, causes a conductance modification. If we can control and direct the nature, the number and the arrangement of the tin dioxide domains, a directed development and improvement of the sensor characteristics is possible. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
A1994NN90000040 |
Publication Date |
2002-07-25 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0925-4005 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
no |
| Call Number |
UA @ admin @ c:irua:82014 |
Serial |
5962 |
| Permanent link to this record |
| |
|
| |
| Author |
Honoré, M.; Lenaerts, S.; Desmet, J.; Huyberechts, G.; Roggen, J. |
| Title |
Synthesis and characterization of tin dioxide powders for the realization of thick-film gas sensors |
Type |
A1 Journal article |
| Year |
1994 |
Publication |
Sensors and actuators : B : chemical |
Abbreviated Journal |
|
| Volume |
19 |
Issue |
|
Pages |
621-624 |
| Keywords |
A1 Journal article |
| Abstract |
Semiconductor gas sensors produced with screen-printing techniques and based on home-made tin dioxide inks are presented. The ink consists of home-made tin dioxide powder added to a polymer solution to make it screen printable on 96% alumina substrates. The major work is performed on the preparation and the characterization of pure undoped tin dioxide powder produced by two different synthetic pathways. Inks prepared with powders from each method are consecutively handled in an identical way to obtain gas sensors. The sensor response towards different gases is measured and compared for both types of starting materials. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
|
Wos |
A1994NN90000073 |
Publication Date |
2002-07-25 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0925-4005 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
no |
| Call Number |
UA @ admin @ c:irua:82013 |
Serial |
5996 |
| Permanent link to this record |
| |
|
| |
| Author |
van Winsen, F.; de Mey, Y.; Lauwers, L.; Van Passel, S.; Vancauteren, M.; Wauters, E. |
| Title |
Cognitive mapping : a method to elucidate and present farmers' risk perception |
Type |
A1 Journal article |
| Year |
2013 |
Publication |
Agricultural Systems |
Abbreviated Journal |
Agr Syst |
| Volume |
122 |
Issue |
|
Pages |
42-52 |
| Keywords |
A1 Journal article |
| Abstract |
Assumptions on the perceptions of risks, made in agricultural economics literature, are recognized to be over-simplistic. For example most studies assume that risks are independent and static, while in reality most risks are interlinked and dynamic. We propose an alternative method to identify and present risk perception, closer to the actual comprehension of risk by farmers. Grounded theory is used to investigate the perceptions of risk by farmers while avoiding prior assumptions. Main findings are: (i) farmers have difficulty to rank or score probability and impact of risks in a (semi)quantitative manner; (ii) farmers attach different meanings to risk, when the focus shifts between, uncertain event, probability or value at stake and; (iii) farmers perceive risks as being interrelated. Based on these findings, we propose that farmers' risk perception can be best understood as a network of interrelated notions of uncertain events, their effects and uncertain outcomes. Furthermore, cognitive mapping is suggested to elucidate and present these networks. We test cognitive mapping, exploring dairy farmers' risk perception, and demonstrate the appropriateness of this methodology for capturing the complexity and context of perceived risk. Advantages are: (i) the qualitative approach, (ii) the focus on interrelations and context, (iii) the applicability at farm level, (iv) the farmer-driven rather than researcher-driven perspective, and (v) the elucidation of the polyvalent use of the risk concept. Cognitive maps can be used as a communication tool, a risk management tool, and a tool to stimulate bi-directional learning amongst farmers, policy makers, researchers and extension agents. (C) 2013 Elsevier Ltd. All rights reserved. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000326910500005 |
Publication Date |
2013-09-12 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0308-521x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
2.571 |
Times cited |
27 |
Open Access |
|
| Notes |
; We would like to acknowledge the Agency for Innovation by Science and Technology of the Flemish Government (IWT) for funding this research. Furthermore we would like to thank the anonymous reviewers for their valuable input. ; |
Approved |
Most recent IF: 2.571; 2013 IF: 2.453 |
| Call Number |
UA @ admin @ c:irua:112765 |
Serial |
6168 |
| Permanent link to this record |
| |
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| |
| Author |
Smets, B.; Boschker, H.T.S.; Wetherington, M.T.; Lelong, G.; Hidalgo-Martinez, S.; Polerecky, L.; Nuyts, G.; De Wael, K.; Meysman, F.J.R. |
| Title |
Multi-wavelength Raman microscopy of nickel-based electron transport in cable bacteria |
Type |
A1 Journal article |
| Year |
2024 |
Publication |
Frontiers in microbiology |
Abbreviated Journal |
|
| Volume |
15 |
Issue |
|
Pages |
1208033-16 |
| Keywords |
A1 Journal article |
| Abstract |
Cable bacteria embed a network of conductive protein fibers in their cell envelope that efficiently guides electron transport over distances spanning up to several centimeters. This form of long-distance electron transport is unique in biology and is mediated by a metalloprotein with a sulfur-coordinated nickel (Ni) cofactor. However, the molecular structure of this cofactor remains presently unknown. Here, we applied multi-wavelength Raman microscopy to identify cell compounds linked to the unique cable bacterium physiology, combined with stable isotope labeling, and orientation-dependent and ultralow-frequency Raman microscopy to gain insight into the structure and organization of this novel Ni-cofactor. Raman spectra of native cable bacterium filaments reveal vibrational modes originating from cytochromes, polyphosphate granules, proteins, as well as the Ni-cofactor. After selective extraction of the conductive fiber network from the cell envelope, the Raman spectrum becomes simpler, and primarily retains vibrational modes associated with the Ni-cofactor. These Ni-cofactor modes exhibit intense Raman scattering as well as a strong orientation-dependent response. The signal intensity is particularly elevated when the polarization of incident laser light is parallel to the direction of the conductive fibers. This orientation dependence allows to selectively identify the modes that are associated with the Ni-cofactor. We identified 13 such modes, some of which display strong Raman signals across the entire range of applied wavelengths (405–1,064 nm). Assignment of vibrational modes, supported by stable isotope labeling, suggest that the structure of the Ni-cofactor shares a resemblance with that of nickel bis(1,2-dithiolene) complexes. Overall, our results indicate that cable bacteria have evolved a unique cofactor structure that does not resemble any of the known Ni-cofactors in biology. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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| Language |
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Wos |
001189511900001 |
Publication Date |
2024-03-08 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1664-302x |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: NA |
| Call Number |
UA @ admin @ c:irua:205115 |
Serial |
9214 |
| Permanent link to this record |
