Sliding Mode Control with Fixed Switching Frequency for Four-wire Shunt Active Filter

Hamoudi, Farid,Chaghi, A. Aziz,Amimeur, Hocine,Merabet, El Kheir The Korean Institute of Electrical Engineers 2011 Journal of Electrical Engineering & Technology Vol.6 No.5

The present paper proposes a sliding mode control with fixed switching frequency for three-phase three-leg voltage source inverter based four-wire shunt active power filter. The aim is to improve phase current waveform, neutral current mitigation, and reactive power compensation in electric power distribution system. The performed sliding mode for active filter current control is formulated using elementary differential geometry. The discrete control vector is deduced from the sliding surface accessibility using the Lyapunov stability. The problem of the switching frequency is addressed by considering hysteresis comparators for the switched signals generation. Through this method, a variable hysteresis band has been established as a function of the sliding mode equivalent control and a predefined switching frequency in order to keep this band constant. The proposed control has been verified with computer simulation which showed satisfactory results.

Effect of scaling and root planing on the expression of anti-inflammatory cytokines (IL-4, IL-9, IL-10, and IL-13) in the gingival crevicular fluid of electronic cigarette users and non-smokers with moderate chronic periodontitis

Al-Hamoudi, Nawwaf,Alsahhaf, Abdulaziz,Deeb, Modhi Al,Alrabiah, Mohammed,Vohra, Fahim,Abduljabbar, Tariq Korean Academy of Periodontology 2020 Journal of Periodontal & Implant Science Vol.50 No.2

Purpose: The aim of this cross-sectional study was to investigate the effect of scaling and root planing (SRP) on the expression of anti-inflammatory cytokines (interleukin [IL]-4, IL-9, IL-10, and IL-13) in the gingival crevicular fluid (GCF) of electronic cigarette users and non-smokers with moderate chronic periodontitis (CP). Methods: Electronic cigarette users and non-smokers with CP were included in the study. Full-mouth plaque and gingival indices, probing depth (PD), clinical attachment loss (CAL), and marginal bone loss (MBL) were assessed. The GCF was collected, and its volume and levels of IL-4, IL-9, IL-10, and IL-13 were assessed. These parameters were evaluated at baseline and 3 months after SRP. The sample size was estimated, and comparisons between groups were performed. P<0.05 was considered to indicate statistical significance. Results: Thirty-six electronic cigarette users (47.7±5.8 years old) and 35 non-smokers (46.5±3.4 years old) with CP were included. At baseline, there were no differences in plaque index (PI), PD, CAL, MBL, and GCF IL-4, IL-9, IL-10, and IL-13 between electronic cigarette users and nonsmokers. At the 3-month follow-up, there were no significant differences in PI, gingival index (GI), PD, CAL, and MBL in electronic cigarette users compared to baseline, while there were significant reductions in PI, GI, and PD among non-smokers. At the 3-month follow-up, GCF IL-4, IL-9, IL-10, and IL-13 levels were significantly elevated in both groups (P<0.05) compared to baseline. The increases in GCF IL-4, IL-9, IL-10, and IL-13 levels were significantly higher in non-smokers (P<0.05) than in electronic cigarette users at the 3-month follow-up. Conclusions: Levels of GCF IL-4, IL-9, IL-10, and IL-13 increased after SRP in electronic cigarette users and non-smokers with CP; however, the anti-inflammatory effect of SRP was more profound in non-smokers than in electronic cigarette users.

Sliding Mode Control with Fixed Switching Frequency for Four-wire Shunt Active Filter

Farid Hamoudi,A. Aziz Chaghi,Hocine Amimeur,El Kheir Merabet 대한전기학회 2011 Journal of Electrical Engineering & Technology Vol.6 No.5

The present paper proposes a sliding mode control with fixed switching frequency for three-phase three-leg voltage source inverter based four-wire shunt active power filter. The aim is to improve phase current waveform, neutral current mitigation, and reactive power compensation in electric power distribution system. The performed sliding mode for active filter current control is formulated using elementary differential geometry. The discrete control vector is deduced from the sliding surface accessibility using the Lyapunov stability. The problem of the switching frequency is addressed by considering hysteresis comparators for the switched signals generation. Through this method, a variable hysteresis band has been established as a function of the sliding mode equivalent control and a predefined switching frequency in order to keep this band constant. The proposed control has been verified with computer simulation which showed satisfactory results.

Effect of scaling and root planing on the expression of anti-inflammatory cytokines (IL-4, IL-9, IL-10, and IL-13) in the gingival crevicular fluid of electronic cigarette users and non-smokers with moderate chronic periodontitis

Nawwaf Al-Hamoudi,Abdulaziz Alsahhaf,Modhi Al Deeb,Mohammed Alrabiah,Fahim Vohra,Tariq Abduljabbar 대한치주과학회 2020 Journal of Periodontal & Implant Science Vol.50 No.2

Purpose: The aim of this cross-sectional study was to investigate the effect of scaling and root planing (SRP) on the expression of anti-inflammatory cytokines (interleukin [IL]-4, IL-9, IL-10, and IL-13) in the gingival crevicular fluid (GCF) of electronic cigarette users and nonsmokers with moderate chronic periodontitis (CP). Methods: Electronic cigarette users and non-smokers with CP were included in the study. Full-mouth plaque and gingival indices, probing depth (PD), clinical attachment loss (CAL), and marginal bone loss (MBL) were assessed. The GCF was collected, and its volume and levels of IL-4, IL-9, IL-10, and IL-13 were assessed. These parameters were evaluated at baseline and 3 months after SRP. The sample size was estimated, and comparisons between groups were performed. P <0.05 was considered to indicate statistical significance. Results: Thirty-six electronic cigarette users (47.7±5.8 years old) and 35 non-smokers (46.5±3.4 years old) with CP were included. At baseline, there were no differences in plaque index (PI), PD, CAL, MBL, and GCF IL-4, IL-9, IL-10, and IL-13 between electronic cigarette users and nonsmokers. At the 3-month follow-up, there were no significant differences in PI, gingival index (GI), PD, CAL, and MBL in electronic cigarette users compared to baseline, while there were significant reductions in PI, GI, and PD among non-smokers. At the 3-month follow-up, GCF IL-4, IL-9, IL-10, and IL-13 levels were significantly elevated in both groups ( P <0.05) compared to baseline. The increases in GCF IL-4, IL-9, IL-10, and IL-13 levels were significantly higher in non-smokers ( P <0.05) than in electronic cigarette users at the 3-month follow-up. Conclusions: Levels of GCF IL-4, IL-9, IL-10, and IL-13 increased after SRP in electronic cigarette users and non-smokers with CP; however, the anti-inflammatory effect of SRP was more profound in non-smokers than in electronic cigarette users.

Study of added resistance and seakeeping of KVLCC2 in waves with and without propeller

Ouargli, Hassiba,Hamoudi, Benameur Techno-Press 2021 Ocean systems engineering Vol.11 No.2

Numerical simulation of a full-scale ship model, KVLCC2, has been conducted applying the Reynolds Averaged Navier-Stokes (RANS) approach using the STARCCM+ commercial computational fluid dynamics (CFD) software to calculate total resistance, seakeeping and Pitch Moments. Results are obtained for the speed of 15.5 Knots under different sea conditions (calm water, regular waves and irregular waves), The total resistance calculated for the KVLCC2 ship hull in calm water is in a good agreement with the results from experiments and the results for motion (heave and pitch) and added resistance in waves were compared to numerical and experimental findings from previous research with good agreement. In addition to wave excitations, the full-scale ship model was subjected to propeller excitations using the virtual disk model from the CFD software. The body force propeller method, which simplified the full propeller characteristic of the KVLCC2 into a resultant body force, is applied to the virtual disk model. Results are compared with results from the hull-only model. A comparison of the wake results with previous work is also presented.

Energy release rate for kinking crack using mixed finite element

Salah, Bouziane,Hamoudi, Bouzerd,Noureddine, Boulares,Mohamed, Guenfoud Techno-Press 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.50 No.5

A numerical method, using a special mixed finite element associated with the virtual crack extension technique, has been developed to evaluate the energy release rate for kinking cracks. The element is two dimensional 7-node mixed finite element with 5 displacement nodes and 2 stress nodes. The mixed finite element ensures the continuity of stress and displacement vectors on the coherent part and the free edge effect. This element has been formulated starting from a parent element in a natural plane with the aim to model different types of cracks with various orientations. Example problems with kinking cracks in a homogeneous material and bimaterial are presented to assess the computational accuracies.

Self-Tuning Fuzzy Logic Controller for a Dual Star Induction Machine

Merabet, Elkheir,Amimeur, Hocine,Hamoudi, Farid,Abdessemed, Rachid The Korean Institute of Electrical Engineers 2011 Journal of Electrical Engineering & Technology Vol.6 No.1

This paper proposes a simple but robust self-tuning fuzzy logic controller for the speed regulation of a dual star induction machine based on indirect field oriented control. For feed the two star of this machine, two voltage source inverters based on sinus-triangular pulse-width modulation techniques are introduced. The simulation results show the robustness and good performance of the proposed controller.

Energy release rate for kinking crack using mixed finite element

Bouziane Salah,Bouzerd Hamoudi,Boulares Noureddine,Guenfoud Mohamed 국제구조공학회 2014 Structural Engineering and Mechanics, An Int'l Jou Vol.50 No.5

A numerical method, using a special mixed finite element associated with the virtual crack extension technique, has been developed to evaluate the energy release rate for kinking cracks. The element is two dimensional 7-node mixed finite element with 5 displacement nodes and 2 stress nodes. The mixed finite element ensures the continuity of stress and displacement vectors on the coherent part and the free edge effect. This element has been formulated starting from a parent element in a natural plane with the aim to model different types of cracks with various orientations. Example problems with kinking cracks in a homogeneous material and bimaterial are presented to assess the computational accuracies.

Influence of adsorption parameters of basic red dye 46 by the rough and treated Algerian natural phosphates

Zahra Graba,Souaad Hamoudi,Djebar Bekka,Nacer Bezzi,Rabah Boukherroub 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.25 No.-

The paper reports on the adsorption behavior of basic red dye 46 from aqueous solution onto rough and treated Algerian natural phosphates. Adsorption tests were realized in static mode on natural rock phosphate and treated samples by sifting, chemical or thermal way. The adsorption process was evaluated as a function of various operating parameters such as contact time, pH of the medium, temperature, concentration, agitation speed and adsorbent mass. The adsorption ability depends mainly on the nature of mineralogical species as well as on the smoothness of the grains. It was found that the dye has more affinity for the carbonate-rich than for the phosphate-rich material. The amount of the dye adsorbed increases with the mass of adsorbent. The adsorption process was pH-dependent with a high adsorption capacity at pH 8. The chemical and thermal treatments performed on different phosphate samples have affected negatively their adsorption capacity of the dye used. The experimental isotherm data were analyzed using the Langmuir, Freundlich and Temkin models. The equilibrium data fit well the Langmuir isotherm. The calculations of the maximum amounts (qm) obtained from this model have shown that it is the fine fraction (T) which adsorbs the highest amount (28.5 mg g1), followed by the coarse fraction (C) (15.62 mg g1) and raw phosphate (RP) (14.7 mg g1). The best results were obtained for dye concentration of 15 mg g1, adsorbent mass of 3 g L1, agitation speed of 300 trs min1, and pH 8 at 20 8C. The experimental data were analyzed using three kinetic models: the pseudo first order, pseudo second order and intraparticle diffusion models. The linear regression, standard statistics of root mean squared error (RMSE) was carried out to support the best fit kinetic models. Based on the low RMSE values, the pseudo second order model is the one that best describes the adsorption of basic red dye 46 on phosphates. The results obtained in this study suggest that Algerian natural phosphates may be used as an efficient and low cost sorbent material for organic pollutants, and thus represent a promising alternative for eliminating dyes from industrial wastewaters.

The effect of thermal treatment on the acid neutralizing capacity of newberyite: structural assessment and kinetics of the HCl neutralization reaction

Hénia Bouzidi Mousser,Aicha Hamoudi,Solenne Fleutot,Sébastien Fontana,Franck Cleymand,Abdelhamid Mousser 한국약제학회 2018 Journal of Pharmaceutical Investigation Vol.48 No.5

The newberyite MgHPO4 ·3H2O antacid activity has never been investigated before. Crystalline and heated Newberyite, at 200 °C, was tested as a neutralizing of hydrogen chloride acid (HCl 0.1 M to simulate gastric juice). Results show that the substrate has a basic behavior and may be used as an active ingredient in the antacid formulation. HCl Neutralization 0.1 M depends of newberyite concentration and pH1 was reached when 0.5 M was used. The crystalline and heated newberyite antacid power was compared with that of some commercial antacids. The newberyite heated pushed pH to 4 after 4 min when the crystalline product was brought it to 3 after 15 min. The antacid neutralizing capacity (ANC) was evaluated using direct and reverse titration methods. ANC values increased when particle sizes decreased. The heated product at 200 °C increased strongly the ANC and the maximum value reached was 13 meq/g. The kinetic study of neutralization reaction was carried out by pHmetry. The rate constants are depending of newberyite quantity and the optimal neutralization of HCl 0.1 M was obtained for 0.5 g. The resulting structural transformations have been investigated. XRD showed that the product became amorphous after heating at 200 °C. FT-IR and Raman spectroscopy agree on departure of the three crystallization water molecules, when MgHPO4 ·3H2O was heated. Surface area measurement was determined by Brunauer, Emmett and Teller and indicates that the product hasn’t an important porosity. Scanning electron microscopy coupled with energy dispersive spectrometry elementary analysis was also carried out and confirmed FT-IR and Raman spectroscopy results.