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Author |
Zhang, Q.-Z.; Bogaerts, A. |
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Title |
Plasma streamer propagation in structured catalysts |
Type |
A1 Journal Article |
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Year |
2018 |
Publication |
Plasma Sources Science & Technology |
Abbreviated Journal |
Plasma Sources Sci T |
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Volume |
27 |
Issue |
10 |
Pages |
105013 |
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Keywords |
A1 Journal Article; plasma catalysis, streamer propagation, 3D structures, PIC/MCC; Plasma, laser ablation and surface modeling Antwerp (PLASMANT) ; |
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Abstract |
Plasma catalysis is gaining increasing interest for various environmental applications. Catalytic
material can be inserted in different shapes in the plasma, e.g., as pellets, (coated) beads, but also
as honeycomb monolith and 3DFD structures, also called ‘structured catalysts’, which have high
mass and heat transfer properties. In this work, we examine the streamer discharge propagation
and the interaction between plasma and catalysts, inside the channels of such structured catalysts,
by means of a two-dimensional particle-in-cell/Monte Carlo collision model. Our results reveal
that plasma streamers behave differently in various structured catalysts. In case of a honeycomb
structure, the streamers are limited to only one channel, with low or high plasma density when
the channels are parallel or perpendicular to the electrodes, respectively. In contrast, in case of a
3DFD structure, the streamers can distribute to different channels, causing discharge
enhancement due to surface charging on the dielectric walls of the structured catalyst, and
especially giving rise to a broader plasma distribution. The latter should be beneficial for plasma
catalysis applications, as it allows a larger catalyst surface area to be exposed to the plasma. |
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Wos |
000448131900002 |
Publication Date |
2018-10-22 |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1361-6595 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.302 |
Times cited |
3 |
Open Access |
Not_Open_Access |
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Notes |
We acknowledge financial support from the European Marie Skłodowska-Curie Individual Fellowship within H2020 (Grant Agreement 702604). This work was carried out in part using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the University of Antwerp. |
Approved |
Most recent IF: 3.302 |
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Call Number |
PLASMANT @ plasmant @c:irua:155510 |
Serial |
5068 |
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Permanent link to this record |
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Author |
Zhang, Q.-Z.; Liu, Y.-X.; Jiang, W.; Bogaerts, A.; Wang, Y.-N. |
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Title |
Heating mechanism in direct current superposed single-frequency and dual-frequency capacitively coupled plasmas |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Plasma sources science and technology |
Abbreviated Journal |
Plasma Sources Sci T |
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Volume |
22 |
Issue |
2 |
Pages |
025014-25018 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
In this work particle-in-cell/Monte Carlo collision simulations are performed to study the heating mechanism and plasma characteristics in direct current (dc) superposed radio-frequency (RF) capacitively coupled plasmas, operated both in single-frequency (SF) and dual-frequency (DF) regimes. An RF (60/2 MHz) source is applied on the bottom electrode to sustain the discharge, and a dc source is fixed on the top electrode. The heating mechanism appears to be very different in dc superposed SF and DF discharges. When only a single source of 60 MHz is applied, the plasma bulk region is reduced by the dc source, thus the ionization rate and hence the electron density decrease with rising dc voltage. However, when a DF source of 60 and 2 MHz is applied, the electron density can increase upon addition of a dc voltage, depending on the gap length and applied dc voltage. This is explained from the spatiotemporal ionization rates in the DF discharge. In fact, a completely different behavior is observed for the ionization rate in the two half-periods of the LF source. In the first LF half-period, the situation resembles the dc superposed SF discharge, and the reduced plasma bulk region due to the negative dc bias results in a very small effective discharge area and a low ionization rate. On the other hand, in the second half-period, the negative dc bias is to some extent counteracted by the LF voltage, and the sheath close to the dc electrode becomes particularly thin. Consequently, the amplitude of the high-frequency sheath oscillations at the top electrode is largely enhanced, while the LF sheath at the bottom electrode is in its expanding phase and can thus well confine the high-energy electrons. Therefore, the ionization rate increases considerably in this second LF half-period. Furthermore, in addition to the comparison between SF and DF discharges and the effect of gap length and dc voltage, the effect of secondary electrons is examined. |
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Thesis |
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Publisher |
Institute of Physics |
Place of Publication |
Bristol |
Editor |
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Wos |
000317275400016 |
Publication Date |
2013-03-28 |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0963-0252;1361-6595; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.302 |
Times cited |
9 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.302; 2013 IF: 3.056 |
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Call Number |
UA @ lucian @ c:irua:106877 |
Serial |
1413 |
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Permanent link to this record |
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Author |
Zhang, Q.-Z.; Wang, W.-Z.; Bogaerts, A. |
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Title |
Importance of surface charging during plasma streamer propagation in catalyst pores |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Plasma sources science and technology |
Abbreviated Journal |
Plasma Sources Sci T |
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Volume |
27 |
Issue |
6 |
Pages |
065009 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Plasma catalysis is gaining increasing interest, but the underlying mechanisms are far from understood. Different catalyst materials will have different chemical effects, but in addition, they might also have different dielectric constants, which will affect surface charging, and thus the plasma behavior. In this work, we demonstrate that surface charging plays an important role in the streamer propagation and discharge enhancement inside catalyst pores, and in the plasma distribution along the dielectric surface, and this role greatly depends on the dielectric constant of the material. For εr50, surface charging causes the plasma to spread along the dielectric surface and inside the pores, leading to deeper plasma streamer penetration, while for εr>50 or for metallic coatings, the discharge is more localized, due to very weak surface charging. In addition, at εr=50, the significant surface charge density near the pore entrance causes a large potential drop at the sharp pore edges, which induces a strong electric field and results in most pronounced plasma enhancement near the pore entrance. |
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Place of Publication |
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Wos |
000436845700002 |
Publication Date |
2018-06-27 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1361-6595 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.302 |
Times cited |
13 |
Open Access |
OpenAccess |
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Notes |
We acknowledge financial support from the European Marie Skłodowska-Curie Individual Fellowship within H2020 (Grant Agreement 702604) and from the TOP-BOF project of the University of Antwerp. This work was carried out in part using the Turing HPC infrastructure at the CalcUA core facility of the Universiteit Antwerpen, a division of the Flemish Supercomputer Center VSC, funded by the Hercules Foundation, the Flemish Government (department EWI) and the University of Antwerp. |
Approved |
Most recent IF: 3.302 |
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Call Number |
PLASMANT @ plasmant @c:irua:152243 |
Serial |
4995 |
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Permanent link to this record |
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Author |
Zhang, Q.; De Clippeleir, H.; Su, C.; Al-Omari, A.; Wett, B.; Vlaeminck, S.E.; Murthy, S. |
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Title |
Deammonification for digester supernatant pretreated with thermal hydrolysis : overcoming inhibition through process optimization |
Type |
A1 Journal article |
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Year |
2016 |
Publication |
Applied microbiology and biotechnology |
Abbreviated Journal |
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Volume |
100 |
Issue |
12 |
Pages |
5595-5606 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
The thermal hydrolysis process (THP) has been proven to be an excellent pretreatment step for an anaerobic digester (AD), increasing biogas yield and decreasing sludge disposal. The goal of this work was to optimize deammonification for efficient nitrogen removal despite the inhibition effects caused by the organics present in the THP-AD sludge filtrate (digestate). Two sequencing batch reactors were studied treating conventional digestate and THP-AD digestate, respectively. Improved process control based on higher dissolved oxygen set-point (1 mg O-2/L) and longer aeration times could achieve successful treatment of THP-AD digestate. This increased set-point could overcome the inhibition effect on aerobic ammonium-oxidizing bacteria (AerAOB), potentially caused by particulate and colloidal organics. Moreover, based on the mass balance, anoxic ammonium-oxidizing bacteria (AnAOB) contribution to the total nitrogen removal decreased from 97 +/- A 1 % for conventional to 72 +/- A 5 % for THP-AD digestate treatment, but remained stable by selective AnAOB retention using a vibrating screen. Overall, similar total nitrogen removal rates of 520 +/- A 28 mg N/L/day at a loading rate of 600 mg N/L/day were achieved in the THP-AD reactor compared to the conventional digestate treatment operating at low dissolved oxygen (DO) (0.38 +/- A 0.10 mg O-2/L). |
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Wos |
000376456700033 |
Publication Date |
2016-02-19 |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0175-7598; 1432-0614 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:134166 |
Serial |
7755 |
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Permanent link to this record |
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Author |
Zhang, R.; Wu, Z.; Li, X.J.; Li, L.L.; Chen, Q.; Li, Y.-M.; Peeters, F.M. |
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Title |
Fano resonances in bilayer phosphorene nanoring |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Nanotechnology |
Abbreviated Journal |
Nanotechnology |
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Volume |
29 |
Issue |
21 |
Pages |
215202 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
Tunable transport properties and Fano resonances are predicted in a circular bilayer phosphorene nanoring. The conductance exhibits Fano resonances with varying incident energy and applied perpendicular magnetic field. These Fano resonance peaks can be accurately fitted with the well known Fano curves. When a magnetic field is applied to the nanoring, the conductance oscillates periodically with magnetic field which is reminiscent of the Aharonov-Bohm effect. Fano resonances are tightly related to the discrete states in the central nanoring, some of which are tunable by the magnetic field. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000428920200001 |
Publication Date |
2018-03-08 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0957-4484 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.44 |
Times cited |
4 |
Open Access |
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Notes |
; This work was supported by Grant No. 2017YFA0303400 from the National Key R&D Program of China, the Flemish Science Foundation, the grants No. 2016YFE0110000, No. 2015CB921503, and No. 2016YFA0202300 from the MOST of China, the NSFC (Grants Nos. 11504366, 11434010, 61674145 and 61774168) and CAS (Grants No. QYZDJ-SSW-SYS001). ; |
Approved |
Most recent IF: 3.44 |
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Call Number |
UA @ lucian @ c:irua:150713UA @ admin @ c:irua:150713 |
Serial |
4968 |
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Permanent link to this record |
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Author |
Zhang, Y.-R.; Gao, F.; Li, X.-C.; Bogaerts, A.; Wang, Y.-N. |
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Title |
Fluid simulation of the bias effect in inductive/capacitive discharges |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Journal of vacuum science and technology: A: vacuum surfaces and films |
Abbreviated Journal |
J Vac Sci Technol A |
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Volume |
33 |
Issue |
33 |
Pages |
061303 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Computer simulations are performed for an argon inductively coupled plasma (ICP) with a capacitive radio-frequency bias power, to investigate the bias effect on the discharge mode transition and on the plasma characteristics at various ICP currents, bias voltages, and bias frequencies. When the bias frequency is fixed at 13.56 MHz and the ICP current is low, e.g., 6A, the spatiotemporal averaged plasma density increases monotonically with bias voltage, and the bias effect is already prominent at a bias voltage of 90 V. The maximum of the ionization rate moves toward the bottom electrode, which indicates clearly the discharge mode transition in inductive/capacitive discharges. At higher ICP currents, i.e., 11 and 13 A, the plasma density decreases first and then increases with bias voltage, due to the competing mechanisms between the ion acceleration power dissipation and the capacitive power deposition. At 11 A, the bias effect is still important, but it is noticeable only at higher bias voltages. At 13 A, the ionization rate is characterized by a maximum at the reactor center near the dielectric window at all selected bias voltages, which indicates that the ICP power, instead of the bias power, plays a dominant role under this condition, and no mode transition is observed. Indeed, the ratio of the bias power to the total power is lower than 0.4 over a wide range of bias voltages, i.e., 0300V. Besides the effect of ICP current, also the effect of various bias frequencies is investigated. It is found that the modulation of the bias power to the spatiotemporal distributions of the ionization rate at 2MHz is strikingly different from the behavior observed at higher bias frequencies. Furthermore, the minimum of the plasma density appears at different bias voltages, i.e., 120V at 2MHz and 90V at 27.12 MHz. |
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Place of Publication |
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Wos |
000365503800020 |
Publication Date |
2015-08-07 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0734-2101;1520-8559; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.374 |
Times cited |
9 |
Open Access |
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Notes |
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Approved |
Most recent IF: 1.374; 2015 IF: 2.322 |
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Call Number |
c:irua:126824 |
Serial |
1229 |
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Permanent link to this record |
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Author |
Zhang, Y.-R.; Neyts, E.C.; Bogaerts, A. |
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Title |
Enhancement of plasma generation in catalyst pores with different shapes |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Plasma sources science and technology |
Abbreviated Journal |
Plasma Sources Sci T |
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Volume |
27 |
Issue |
5 |
Pages |
055008 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
Plasma generation inside catalyst pores is of utmost importance for plasma catalysis, as the existence of plasma species inside the pores affects the active surface area of the catalyst available to the plasma species for catalytic reactions. In this paper, the electric field enhancement, and thus the plasma production inside catalyst pores with different pore shapes is studied with a two-dimensional fluid model. The results indicate that the electric field will be significantly enhanced near tip-like structures. In a conical pore with small opening, the strongest electric field appears at the opening and bottom corners of the pore, giving rise to a prominent ionization rate throughout the pore. For a cylindrical pore, the electric field is only enhanced at the bottom corners of the pore, with lower absolute value, and thus the ionization rate inside the pore is only slightly enhanced. Finally, in a conical pore with large opening, the electric field is characterized by a maximum at the bottom of the pore, yielding a similar behavior for the ionization rate. These results demonstrate that the shape of the pore has a significantly influence on the electric field enhancement, and thus modifies the plasma properties. |
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Corporate Author |
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Thesis |
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Place of Publication |
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Wos |
000432351700002 |
Publication Date |
2018-05-15 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1361-6595 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.302 |
Times cited |
11 |
Open Access |
OpenAccess |
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Notes |
This work was supported by the Fund for Scientific Research Flanders (FWO) (Grant No. G.0217.14N) and the Fundamental Research Funds for the Central Universities (Grant No. DUT17LK52). |
Approved |
Most recent IF: 3.302 |
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Call Number |
PLASMANT @ plasmant @c:irua:151546 |
Serial |
4998 |
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Permanent link to this record |
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Author |
Zhang, Y.-R.; Tinck, S.; De Schepper, P.; Wang, Y.-N.; Bogaerts, A. |
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Title |
Modeling and experimental investigation of the plasma uniformity in CF4/O2 capacitively coupled plasmas, operating in single frequency and dual frequency regime |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Journal of vacuum science and technology: A: vacuum surfaces and films |
Abbreviated Journal |
J Vac Sci Technol A |
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Volume |
33 |
Issue |
33 |
Pages |
021310 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
A two-dimensional hybrid Monte Carlofluid model, incorporating a full-wave solution of Maxwell's equations, is employed to describe the behavior of high frequency (HF) and very high frequency capacitively coupled plasmas (CCPs), operating both at single frequency (SF) and dual frequency (DF) in a CF4/O2 gas mixture. First, the authors investigate the plasma composition, and the simulations reveal that besides CF4 and O2, also COF2, CF3, and CO2 are important neutral species, and CF+3 and F− are the most important positive and negative ions. Second, by comparing the results of the model with and without taking into account the electromagnetic effects for a SF CCP, it is clear that the electromagnetic effects are important, both at 27 and 60 MHz, because they affect the absolute values of the calculation results and also (to some extent) the spatial profiles, which accordingly affects the uniformity in plasma processing. In order to improve the plasma radial uniformity, which is important for the etch process, a low frequency (LF) source is added to the discharge. Therefore, in the major part of the paper, the plasma uniformity is investigated for both SF and DF CCPs, operating at a HF of 27 and 60 MHz and a LF of 2 MHz. For this purpose, the authors measure the etch rates as a function of position on the wafer in a wide range of LF powers, and the authors compare them with the calculated fluxes toward the wafer of the plasma species playing a role in the etch process, to explain the trends in the measured etch rate profiles. It is found that at a HF of 60 MHz, the uniformity of the etch rate is effectively improved by adding a LF power of 2 MHz and 300 W, while its absolute value increases by about 50%, thus a high etch rate with a uniform distribution is observed under this condition. |
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Corporate Author |
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Publisher |
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Place of Publication |
New York, N.Y. |
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Language |
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Wos |
000355739500026 |
Publication Date |
2015-01-29 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0734-2101;1520-8559; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.374 |
Times cited |
3 |
Open Access |
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Notes |
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Approved |
Most recent IF: 1.374; 2015 IF: 2.322 |
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Call Number |
c:irua:122650 |
Serial |
2107 |
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Permanent link to this record |
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Author |
Zhang, Y.; Wang, H.-yu; Zhang, Y.-ru; Bogaerts, A. |
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Title |
Formation of microdischarges inside a mesoporous catalyst in dielectric barrier discharge plasmas |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Plasma sources science and technology |
Abbreviated Journal |
Plasma Sources Sci T |
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Volume |
26 |
Issue |
26 |
Pages |
054002 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
The formation process of a microdischarge (MD) in both μm- and nm-sized catalyst pores is simulated by a two-dimensional particle-in-cell/Monte Carlo collision model. A parallel-plate dielectric barrier discharge configuration in filamentary mode is considered in ambient air. The discharge is powered by a high voltage pulse. Our calculations reveal that a streamer can penetrate into the surface features of a porous catalyst and MDs can be formed inside both μm- and nm-sized pores, yielding ionization inside the pore. For the μm-sized pores, the ionization mainly occurs inside the pore, while for the nm-sized pores the ionization is strongest near and inside the pore. Thus, enhanced discharges near and inside the mesoporous catalyst are observed. Indeed, the maximum values of the electric field, ionization rate and electron density occur near and inside the pore. The maximum electric field and electron density inside the pore first increase when the pore size rises from 4 nm to 10 nm, and then they decrease for the 100 nm pore, due to
a more pronounced surface discharge for the smaller pores. However, the ionization rate is highest for the 100 nm pore due to the largest effective ionization region. |
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Place of Publication |
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Wos |
000399277700001 |
Publication Date |
2017-04-05 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1361-6595 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.302 |
Times cited |
15 |
Open Access |
OpenAccess |
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Notes |
This work was supported by the NSFC (11405067, 11275007, 11375163). Y Zhang gratefully acknowledges the Belgian Federal Science Policy Office for financial support. The authors are very grateful to Wei Jiang for the useful discussions on the photo-ionization model and the particle-incell/ Monte-Carlo model. |
Approved |
Most recent IF: 3.302 |
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Call Number |
PLASMANT @ plasmant @ c:irua:142806 |
Serial |
4566 |
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Permanent link to this record |
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Author |
Zhang, Z.Z.; Wu, Z.H.; Chang, K.; Peeters, F.M. |
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Title |
Resonant tunneling through S- and U-shaped graphene nanoribbons |
Type |
A1 Journal article |
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Year |
2009 |
Publication |
Nanotechnology |
Abbreviated Journal |
Nanotechnology |
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Volume |
20 |
Issue |
41 |
Pages |
415203,1-415203,7 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We theoretically investigate resonant tunneling through S- and U-shaped nanostructured graphene nanoribbons. A rich structure of resonant tunneling peaks is found emanating from different quasi-bound states in the middle region. The tunneling current can be turned on and off by varying the Fermi energy. Tunability of resonant tunneling is realized by changing the width of the left and/or right leads and without the use of any external gates. |
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Publisher |
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Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000269930100007 |
Publication Date |
2009-09-17 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0957-4484;1361-6528; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.44 |
Times cited |
32 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.44; 2009 IF: 3.137 |
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Call Number |
UA @ lucian @ c:irua:79311 |
Serial |
2893 |
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Permanent link to this record |
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Author |
Zhao, S.-X.; Gao, F.; Wang, Y.-N.; Bogaerts, A. |
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Title |
The effect of F2 attachment by low-energy electrons on the electron behaviour in an Ar/CF4 inductively coupled plasma |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Plasma sources science and technology |
Abbreviated Journal |
Plasma Sources Sci T |
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Volume |
21 |
Issue |
2 |
Pages |
025008-025008,13 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
The electron behaviour in an Ar/CF4 inductively coupled plasma is investigated by a Langmuir probe and a hybrid model. The simulated and measured results include electron density, temperature and electron energy distribution function for different values of Ar/CF4 ratio, coil power and gas pressure. The hybrid plasma equipment model simulations show qualitative agreement with experiment. The effect of F2 electron attachment on the electron behaviour is explored by comparing two sets of data based on different F atom boundary conditions. It is demonstrated that electron attachment at F2 molecules is responsible for the depletion of low-energy electrons, causing a density decrease as well as a temperature increase when CF4 is added to an Ar plasma. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
Institute of Physics |
Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000302779400022 |
Publication Date |
2012-03-12 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0963-0252;1361-6595; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.302 |
Times cited |
23 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.302; 2012 IF: 2.515 |
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Call Number |
UA @ lucian @ c:irua:96549 |
Serial |
841 |
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Permanent link to this record |
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Author |
Zhao, S.-X.; Gao, F.; Wang, Y.-N.; Bogaerts, A. |
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Title |
Gas ratio effects on the Si etch rate and profile uniformity in an inductively coupled Ar/CF4 plasma |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Plasma sources science and technology |
Abbreviated Journal |
Plasma Sources Sci T |
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Volume |
22 |
Issue |
1 |
Pages |
015017-15018 |
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Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
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Abstract |
In this work, a hybrid model is used to investigate the effect of different gas ratios on the Si etching and polymer film deposition characteristics in an Ar/CF4 inductively coupled plasma. The influence of the surface processes on the bulk plasma properties is studied, and also the spatial characteristics of important gas phase and etched species. The densities of F and CF2 decrease when the surface module is included in the simulations, due to the species consumption caused by etching and polymer deposition. The influence of the surface processes on the bulk plasma depends on the Ar/CF4 gas ratio. The deposited polymer becomes thicker at high CF4 content because of more abundant CFx radicals. As a result of the competition between the polymer thickness and the F flux, the etch rate first increases and then decreases upon increasing the CF4 content. The electron properties, more specifically the electron density profile, affect the Si etch characteristics substantially by determining the radical density and flux profiles. In fact, the radial profile of the etch rate is more uniform at low CF4 content since the electron density has a smooth distribution. At high CF4 content, the etch rate is less uniform with a minimum halfway along the wafer radius, because the electron density distribution is more localized. Therefore, our calculations predict that it is better to work at relatively high Ar/CF4 gas ratios, in order to obtain high etch rate and good profile uniformity for etch applications. This, in fact, corresponds to the typical experimental etch conditions in Ar/CF4 gas mixtures as found in the literature, where Ar is typically present at a much higher concentration than CF4. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
Institute of Physics |
Place of Publication |
Bristol |
Editor |
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Language |
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Wos |
000314966300022 |
Publication Date |
2012-12-20 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0963-0252;1361-6595; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.302 |
Times cited |
11 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.302; 2013 IF: 3.056 |
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Call Number |
UA @ lucian @ c:irua:102583 |
Serial |
1320 |
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Permanent link to this record |
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Author |
Zhou, S.; Zhang, C.; Xu, W.; Zhang, J.; Xiao, Y.; Ding, L.; Wen, H.; Cheng, X.; Hu, C.; Li, H.; Li, X.; Peeters, F.M. |
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Title |
Observation of temperature induced phase transitions in TiO superconducting thin film via infrared measurement |
Type |
A1 Journal article |
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Year |
2024 |
Publication |
Infrared physics and technology |
Abbreviated Journal |
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Volume |
137 |
Issue |
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Pages |
105160-105169 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
In contrast to conventional polycrystalline titanium oxide (TiO), it was found recently that the superconducting transition temperature Tc can be significantly enhanced from about 2 K to 7.4 K in cubic TiO thin films grown epitaxially on alpha-Al2O3 substrates. This kind of TiO film is also expected to have distinctive optoelectronic properties, which are still not very clear up to now. Herein, by using infrared (IR) reflection measurement we investigate the temperature-dependent optoelectronic response of a cubic TiO thin film, in which temperature induced phase transitions are observed. The semiconductor-, metallic- and semiconductor-like electronic phases of this superconducting film are found in the temperature regimes from 10 to 110 K, 110 to 220 K and above 220 K, respectively. The results obtained optically are consistent with those measured by transport experiment. Furthermore, based on an improved reflection model developed here, we extract the complex optical conductivity of the cubic TiO thin film. We are able to approximately determine the characteristic parameters (e.g., effective electron mass, carrier density, scattering time, etc.) for different electronic phases by fitting the optical conductivity with the modified Lorentz formula. These results not only deepen our understanding of the fundamental physics for cubic TiO thin films but also may find applications in optoelectronic devices based on superconductors. |
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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 |
001170490200001 |
Publication Date |
2024-01-21 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1350-4495 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
3.3 |
Times cited |
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Open Access |
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Notes |
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Approved |
Most recent IF: 3.3; 2024 IF: 1.713 |
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Call Number |
UA @ admin @ c:irua:204853 |
Serial |
9162 |
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Permanent link to this record |
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Author |
Zhu, W.; Li, J.; Wang, B.; Chen, G. |
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Title |
Enhancement of pollutants removal from saline wastewater through simultaneous anammox and denitrification (SAD) process with glycine betaine addition |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Bioresource Technology |
Abbreviated Journal |
Bioresource Technol |
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Volume |
315 |
Issue |
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Pages |
123784 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
Enhanced pollutants removal from saline wastewater was investigated in simultaneous anammox and denitrification (SAD) process with glycine betaine (GB) addition. Long-term operation indicated the optimal GB dose was around 0.4 mM, which enhanced both anammox and denitrifying activity by 30% and 45%, respectively. The total nitrogen and organic removal rates were 0.38 +/- 0.2 kgN/m(3)/d and 0.34 +/- 0.3 kgCOD/m(3)/d, respectively, which increased by 34.5% and 20.5%. Independent of GB dose, denitrifying activity was promoted, but anammox activity was drastically deteriorated after excessive GB addition. The optimal GB dose predicated by both Gaussian and Modified-Boltzmann models were 0.42-0.45 mM. Besides, the bacterial activity recovery after excessive GB addition could be analyzed by the Modified-Boltzmann model. With 1.5 mM GB, granular floatation occurred since numerous gas bubbles were inside the granules. In general, exogenous GB addition can mitigate salinity inhibition and promote pollutants removal from saline wastewater. |
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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 |
000560717900013 |
Publication Date |
2020-07-06 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0960-8524 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
11.4 |
Times cited |
1 |
Open Access |
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Notes |
; This study was financially supported by the National Natural Science Foundation of China (51878362), China Postdoctoral Science Foundation (2017M610410, 2018T110665) and State Key Joint Laboratory of Environment Simulation and Pollution Control (Research Center for Eco-environmental Sciences, Chinese Academy of Sciences) (18K02ESPCR). The authors also thank Dr. Yuan Hou and Dr. Chao Fang from University of Antwerp for numerous discussion. ; |
Approved |
Most recent IF: 11.4; 2020 IF: 5.651 |
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Call Number |
UA @ admin @ c:irua:171118 |
Serial |
6508 |
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Permanent link to this record |
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Author |
Zhu, W.; Van Tendeloo, M.; Alloul, A.; Vlaeminck, S.E. |
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Title |
Towards mainstream partial nitritation/anammox in four seasons : feasibility of bioaugmentation with stored summer sludge for winter anammox assistance |
Type |
A1 Journal article |
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Year |
2022 |
Publication |
Bioresource technology |
Abbreviated Journal |
Bioresource Technol |
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Volume |
347 |
Issue |
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Pages |
126619-11 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
The strong effect of low temperatures on anammox challenges its mainstream application over the winter in temperate climates. Winter bioaugmentation with stored summer surplus sludge is a potential solution to guarantee sufficient nitrogen removal in winter. Firstly, the systems for which nitrogen removal deteriorated by the temperature decrease (25 °C → 20 °C) could be fully restored bioaugmenting with granules resp. flocs stored for 6 months at 118 resp. 220% of the initial biomass levels. Secondly, the reactivation of these stored sludges was tested in lower temperature systems (15.3 ± 0.4/10.4 ± 0.4 °C). Compared to the activity before storage, between 56% and 41% of the activity of granules was restored within one month, and 41%–32% for flocs. Additionally, 85–87% of granules and 50–53% of flocs were retained in the systems. After reactivation (15.3 ± 0.4/10.4 ± 0.4 °C), a more specialized community was formed (diversity decreased) with Candidatus Brocadia still dominant in terms of relative abundance. Capital and operating expenditures (CAPEX, OPEX) were negligible, representing only 0.19–0.36% of sewage treatment costs. |
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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 |
000781730900001 |
Publication Date |
2021-12-25 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0960-8524 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
11.4 |
Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 11.4 |
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Call Number |
UA @ admin @ c:irua:185210 |
Serial |
7220 |
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Permanent link to this record |
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Author |
Zhu, W.; Van Tendeloo, M.; Alloul, A.; Vlaeminck, S.E. |
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Title |
Feasibility of a return-sludge nursery concept for mainstream anammox biostimulation : creating optimal conditions for anammox to recover and grow in a parallel tank |
Type |
A1 Journal article |
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Year |
2023 |
Publication |
Bioresource technology |
Abbreviated Journal |
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Volume |
385 |
Issue |
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Pages |
129359-12 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
To overcome limiting anammox activity under sewage treatment conditions, a return-sludge nursery concept is proposed. This concept involves blending sludge reject water treated with partial nitritation with mainstream effluent to increase the temperature, N levels, and electrical conductivity (EC) of the anammox nursery reactor, which sludge periodically passes through the return sludge line of the mainstream system. Various nursery frequencies were tested in two 2.5 L reactors, including 0.5-2 days of nursery treatment per 3.5-14 days of the total operation. Bioreactor experiments showed that nursery increased nitrogen removal rates during mainstream operation by 33-38%. The increased anammox activity can be partly (35-60%) explained by higher temperatures. Elevated EC, higher nitrogen concentrations, and a putative synergy and/or unknown factor were responsible for 15-16%, 12-14%, and 10-36%, respectively. A relatively stable microbial community was observed, dominated by a “Candidatus Brocadia” member. This new concept boosted activity and sludge growth, which may facilitate mainstream anammox implementations based on partial nitritation/anammox or partial nitrification/denitratation/anammox. |
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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 |
001031586400001 |
Publication Date |
2023-06-19 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0960-8524 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
11.4 |
Times cited |
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Open Access |
Not_Open_Access |
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Notes |
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Approved |
Most recent IF: 11.4; 2023 IF: 5.651 |
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Call Number |
UA @ admin @ c:irua:198259 |
Serial |
8866 |
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Permanent link to this record |
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Author |
Zhu, W.; Van Tendeloo, M.; De Paepe, J.; Vlaeminck, S.E. |
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Title |
Comparison of typical nitrite oxidizing bacteria suppression strategies and the effect on nitrous oxide emissions in a biofilm reactor |
Type |
A1 Journal article |
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Year |
2023 |
Publication |
Bioresource technology |
Abbreviated Journal |
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Volume |
387 |
Issue |
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Pages |
129607-129609 |
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Keywords |
A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL) |
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Abstract |
In mainstream partial nitritation/anammox (PN/A), suppression of nitrite oxidizing bacteria (NOB) and mitigation of N2O emissions are two essential operational goals. The N2O emissions linked to three typical NOB suppression strategies were tested in a covered rotating biological contactor (RBC) biofilm system at 21 degrees C: (i) low dissolved oxygen (DO) concentrations, and treatments with (ii) free ammonia (FA), and (iii) free nitrous acids (FNA). Low emerged DO levels effectively minimized NOB activity and decreased N2O emissions, but NOB adaptation appeared after 200 days of operation. Further NOB suppression was successfully achieved by periodic (3 h per week) treatments with FA (29.3 & PLUSMN; 2.6 mg NH3-N L-1) or FNA (3.1 & PLUSMN; 0.3 mg HNO2-N L-1). FA treatment, however, promoted N2O emissions, while FNA did not affect these. Hence, biofilm PN/A should be operated at relatively low DO levels with periodic FNA treatment to maximize nitrogen removal efficiency while avoiding high greenhouse gas emissions. |
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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 |
001063180200001 |
Publication Date |
2023-08-05 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0960-8524 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
11.4 |
Times cited |
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Open Access |
Not_Open_Access: Available from 21.02.2024 |
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Notes |
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Approved |
Most recent IF: 11.4; 2023 IF: 5.651 |
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Call Number |
UA @ admin @ c:irua:199051 |
Serial |
8843 |
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Permanent link to this record |