| 1. |
- Wang, Z., et al.
(author)
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Hydroxyl radical dynamics in a gliding arc discharge using high-speed PLIF imaging
- 2022
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In: Plasma Research Express. - : IOP Publishing. - 2516-1067. ; 4:2
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Journal article (peer-reviewed)abstract
- Plasma discharges can be transient and randomly distributed where a few investigations have been carried out using laser-induced fluorescence to capture snapshots of plasma-produced radicals in the near vicinity of the discharge. Radical distribution dynamics, however, are challenging to study in situ with high spatial and temporal resolution to fully capture the interactions between the discharge and the gas. We here demonstrate a planar laser-induced fluorescence method that can capture molecular distributions of ground state hydroxyl radicals in a discharge plasma and follow how the distribution develops in time with a repetition rate of 27 kHz. The technique is demonstrated by monitoring, in real-time, how the tube-like distribution of ground state OH radicals, surrounding a gliding arc plasma, is affected by flow dynamics and how it develops as the high voltage is turned off at atmospheric pressure. The method presented here is an essential tool for capturing radical-distribution dynamics in situ of chemically active environments which is the active region of the plasma induced chemistry.
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| 2. |
- Bardos, Ladislav, et al.
(author)
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Shaping od the flame geometry by non-conventional cold plasma arrangements
- 2020
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In: Plasma Research Express. - : IOP Publishing. - 2516-1067. ; 2:3
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Journal article (peer-reviewed)abstract
- Experimental examination of possibility to affect the shapes of flames under combustion of the liquified petroleum gas (LPG) were performed by several non-conventional cold atmospheric plasma arrangements. The lateral fused hollow cathode, the microwave surface wave plasma jet and the combination of these systems confirmed possibility of an efficient control of the flame shapes, increasing stability of flames and broadening of their front parts.
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| 3. |
- Doyle, S J, et al.
(author)
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Single and double null equilibria in the SMART Tokamak
- 2021
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In: Plasma Research Express. - : IOP Publishing. - 2516-1067. ; 3:4
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Journal article (peer-reviewed)abstract
- The SMall Aspect Ratio Tokamak (SMART) device is a novel, compact (Rgeo = 0.42 m, a = 0.22 m, A 1.70) spherical tokamak, currently under development at the University of Seville. The SMART device is being developed over 3 phases, with target on-axis toroidal magnetic fields between 0.1 ≼ Bf ≼ 1.0 T, and target plasma currents of between 35 ≼ Ip ≼ 400 kA; with phases 2 and 3 enabling access to a wide range of elongations (κ ≼ 2.30) and triangularities (− 0.50 ≼ δ ≼ 0.50). SMART employs four internal divertor coils with two internal and two external poloidal field coils, enabling operation in lower-single, upper-single and double-null configurations. This work examines phase 3 of the SMART device, presenting a prospective L-mode discharge scenario without external heating, before examining five highly-shaped equilibria, including: two double null triangular configurations, two single null triangular configurations and a baseline double null configuration. All equilibria are obtained via an axisymmetric Grad-Shafranov force balance solver (Fiesta), in combination with a circuit equation rigid current displacement model (RZIp) to obtain time-resolved vessel and plasma currents.
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| 4. |
- Klintberg, Lena, et al.
(author)
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Partial least squares modelling of spectroscopic data from microplasma emissions for determination of CO2 concentration
- 2020
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In: Plasma Research Express. - : IOP Publishing. - 2516-1067. ; 2:4
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Journal article (peer-reviewed)abstract
- The spectral emissions from a microplasma have been used to predict the CO2 concentration in gas samples covering a concentration range of 0%–100%. Different models based on partial least squares have been evaluated, comparing two different spectral pre-processing filters – multiplicative scatter correction (MSC) and standard normal variate correction (SNV) – and three different wavelength ranges. The models were compared with respect to accuracy, precision, stability and linearity. CO2 samples were mixed with either air or nitrogen. The choice of mixing gas influenced the predicted concentration and basing the models on data from only one mixing gas resulted in higher prediction power. Using air as mixing gas and SNV filtering resulted in a root mean square error of prediction (RMSEP) of 0.03 for an independent test dataset. This RMSEP was of the same range as the experimental error. On the other hand, the models with the best long term stability, reaching the lowest Allan variance, were based on observations with both mixing gases. Models based on MSC filtering generally had slightly higher RMSEP than those based on SNV filtering. Generally, the CO2 concentration could be accurately predicted in the concentration range of 5%–90%. For higher and lower concentrations, the models underestimated the CO2 concentration and were less accurate and precise. Basing the models on fewer wavelengths resulted in reduced linearity. The models were also evaluated by applying them for transcutaneous blood gas monitoring, where they helped to reveal new physiological information.
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| 5. |
- Moreno, Quentin, et al.
(author)
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Failed self-reformation of a sub-critical fast magnetosonic shock in collisionless plasma
- 2019
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In: Plasma Research Express. - : Institute of Physics Publishing (IOPP). - 2516-1067. ; 1:3
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Journal article (peer-reviewed)abstract
- We study with a 1D particle-in-cell (PIC) simulation the evolution of a subcritical perpendicular fast magnetosonic shock. The shock propagates at 1.5 times the fast magnetosonic speed. Some upstream protons are reflected by the shock's electric potential. They form a beam which carries less energy than those that are reflected magnetically by super-critical shocks. The beam triggers the growth of a fast magnetosonic solitary wave upstream of the shock, which reflects the beam protons back to the shock. Extracting the momentum and energy of this beam allows the solitary wave to grow into a proto-shock that is trailed by a short downstream region. Protons from the shock-reflected proton beam increase the density of the plasma between the shock and the proto-shock reducing its potential difference relative to both surrounding structures. Bulk protons, which cross the proto-shock, react to the decreased potential jump. The plasma behind the proto-shock accelerates and so does the shock. The trailing end of the proto-shock speeds up in order to continue reflecting the beam protons and eventually it catches up with its front; the proto-shock collapses and the self-reformation fails. A more energetic proton beam could decrease the potential jump across the shock, let it collapse and replace it with the proto-shock.
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| 6. |
- Carlsson, Åke
(author)
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Unsuccessful use of a titanium mesh cage in ankle arthrodesis: a report on three cases operated on due to a failed ankle replacement.
- 2008
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In: The Journal of Foot & Ankle Surgery. - : Elsevier BV. - 1542-2224 .- 1067-2516. ; 47:4, s. 337-342
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Journal article (peer-reviewed)abstract
- Three patients with a failed total ankle arthroplasty underwent tibiocalcaneal arthrodesis. In an attempt to preserve leg length, a titanium cage filled with autologous bone was placed in the defect. None of the ankles healed primarily. After 9 to 29 months, the cages, which only contained necrotic material, were removed and repeat arthrodesis was performed using a retrograde intramedullary nail. After this procedure, 1 ankle had healed after 14 months whereas 2 did not heal. However, after a third attempt, using external fixation, 1 of the latter 2 healed. The method used in this report cannot be recommended. Although titanium mesh cages filled with autograft have been successfully used to substitute for vertebral defects, the author does not feel that the method can be recommended for ankle arthrodesis.
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| 7. |
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| 8. |
- Henricson, Anders, et al.
(author)
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Bilateral Arthrodesis of the Ankle Joint : Self-Reported Outcomes in 35 Patients From the Swedish Ankle Registry
- 2016
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In: The Journal of Foot & Ankle Surgery. - : Elsevier BV. - 1067-2516. ; 55:6, s. 1195-1198
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Journal article (peer-reviewed)abstract
- Bilateral ankle arthrodesis is seldom performed, and results concerning the outcome and satisfaction can only sparsely be found in published studies. We analyzed the data from 35 patients who had undergone bilateral ankle arthrodesis in the Swedish Ankle Registry using patient-reported generic and region-specific outcome measures. Of 36 talocrural arthrodeses and 34 tibio-talar-calcaneal arthrodeses, 6 ankles (9%) had undergone repeat arthrodesis because of nonunion. After a mean follow-up period of 47 ± 5 (range 12 to 194) months, the mean scores were as follows: self-reported foot and ankle score, 33 ± 10 (range 4 to 48); the EuroQol Group's EQ-5D™ score, 0.67 ± 0.28 (range −0.11 to 1), the EuroQol Group's visual analog scale score, 70 ± 19 (range 20 to 95), 36-item Short Form Health Survey (SF-36) physical domain, 39 ± 11 (range 16 to 58); and SF-36 mental domain, 54 ± 14 (range 17 to 71). Patients with rheumatoid arthritis seemed to have similar self-reported foot and ankle scores but possibly lower EQ-5D™ and SF-36 scores. Those with talocrural arthrodeses scored higher than did those with tibio-talar-calcaneal arthrodeses on the EQ5D™ and SF-36 questionnaires (p = .03 and p = .04). In 64 of 70 ankles (91%), the patients were satisfied or very satisfied with the outcome. In conclusion, we consider bilateral ankle arthrodesis to be a reasonable treatment for symptomatic hindfoot arthritis, with high postoperative mid-term satisfaction and satisfactory scores on the patient-reported generic and region-specific outcome measures, when no other treatment option is available.
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| 9. |
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| 10. |
- Rolf, C, et al.
(author)
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Plantar fascia rupture: diagnosis and treatment
- 1997
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In: The Journal of foot and ankle surgery : official publication of the American College of Foot and Ankle Surgeons. - : Elsevier BV. - 1067-2516. ; 36:2, s. 112-4
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Journal article (peer-reviewed)
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