Synthesis of heteroatoms doped reduced graphene oxide for the electrochemical determination of uric acid in commercial milk

Fatma Besbes,Zouhour Hsine,Rym Mlika 한국탄소학회 2023 Carbon Letters Vol.33 No.7

A simple and one-pot synthetic procedure using two different sources has been demonstrated to prepare heteroatoms doped reduced graphene oxide such as nitrogen-doped reduced graphene oxide (N-RGO) and sulfur-doped reduced graphene oxide (S-RGO). The N-RGO has been hydrothermally synthesized using urea as nitrogen precursor, wherein the S-RGO has been synthesized using dimethyl sulfoxide (DMSO) as sulfur precursor. The successful N-doping, S-doping and other physicochemical properties of N-RGO and S-RGO have been confirmed with different spectroscopic and electrochemical techniques. The results indicated that doping into the graphene structure exhibits a high conductivity and a better transfer of charge. Moreover, heteroatoms doped graphene (N-RGO and S-RGO) and graphene-related materials (RGO) have been applied for the individual detection of uric acid (UA). Interestingly, the N-RGO exhibited a lower limit of detection (LOD, S/N = 3) of 2.7 10– 5 M for UA (10–1000 μM) compared with undoped RGO and S-RGO. Furthermore, the simultaneous detection of UA in the presence of Xanthine (XA) has been demonstrated a wide linear range of detection for UA: 10–1000 μM, with unchanged concentration of XA to be 200 μM, and exhibited a low limit of detection of 8.7 10? 5 M ( S?N = 3) for UA. This modified sensor based on N-RGO has revealed a high selectivity and reproducibility thanks to its large surface area, high catalytic properties, and chemical structure. Indeed, the practical applicability of the proposed sensor has been evaluated in milk samples even in the presence of high concentrations of UA with satisfactory results.

Design of an Integrated Inductor with Magnetic Core for Micro-Converter DC-DC Application

Dhahri, Yassin,Ghedira, Sami,Besbes, Kamel The Korean Institute of Electrical and Electronic 2016 Transactions on Electrical and Electronic Material Vol.17 No.6

This paper presents a design procedure of an integrated inductor with a magnetic core for power converters. This procedure considerably reduces design time and effort. The proposed design procedure is verified by the development of an inductor model dedicated to the monolithic integration of DC-DC converters for portable applications. The numerical simulation based on the FEM (finite elements method) shows that 3D modeling of the integrated inductor allows better estimation of the electrical parameters of the desired inductor. The optimization of the electrical parameter values is based on the numerical analysis of the influence of the geometric parameters on the electrical characteristics of the inductor. Using the VHDL-AMS language, implementation of the integrated inductor in a micro Buck converter demonstrate that simulation results present a very promising approach for the monolithic integration of DC-DC converters.

Optimization of Aspergillus oryzae S2 α-amylase, ascorbic acid, and glucose oxidase combination for improved French and composite Ukrainian wheat dough properties and bread quality using a mixture design approach

Sahnoun, Mouna,Kriaa, Mouna,Besbes, Souhail,Jardak, Mohamed,Bejar, Samir,Kammoun, Radhouane 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.5

A simplex-centroid experimental design was used for the optimization of both reducing and oxidizing improvers, namely Aspergillus oryzae S2 ${\alpha}$-amylase (Amy), ascorbic acid (Asc), and glucose oxidase (GOD). This optimization was performed to enhance the dough and breadmaking qualities of soft French wheat flour and a composite counterpart that contained 30% Ukrainian wheat flour. Statistically significant correlations were calculated between the W index and textural parameters (e.g., dough chewiness and bread cohesiveness). The findings revealed that while the best mixture for French flour comprised 21.8% of Amy, 41.2% of Asc, and 37% of GOD, for the composite counterpart, it comprised 2.3% of Amy, 66% of Asc, and 31.7% of GOD. These optimized mixtures rearranged soft French wheat flour and its composite counterpart to a good quality and an improved flour texture, respectively. Additionally, they increased the loaf specific volumes of the breads made from soft French wheat flour and its counterpart by 25.8 and 45.43%, respectively, significantly decreased the breads' susceptibility to microbial contamination, and reclassified the breads as "good" in terms of sensory attributes.

Improvement of Bread Quality and Bread Shelf-life by Bacillus subtilis Biosurfactant Addition

Ines Mnif,Souhail Besbes,Raoudha Ellouze,Semia Ellouze-Chaabouni,Dhouha Ghribi 한국식품과학회 2012 Food Science and Biotechnology Vol.21 No.4

The objective of the present work was to determine the effect of the addition of a microorganism derived emulsifier on the quality of bread. The effect of Bacillus subtilis SPB1 biosurfactant has been investigated in comparison to a commercial surfactant, the soya lecithin. Indeed, it led to a better shape and a greater specific volume and voided fraction of loaves. Also, results showed that SPB1 bioemulsifier addition improved considerably the texture profile of bread, mainly at a concentration of 0.075%(w/w). In fact, we showed a notable decrease of firmness, chewiness, and adhesion values with a slight increase of cohesion for bread added emulsifier. According to crumb texture evolution during storage, SPB1 biosurfactant exhibited a significant antistaling effect. Moreover, SPB1biosurfactant addition reduced significantly bread susceptibility to microbial contamination. These results proved that SPB1 biosurfactant could be of a great interest in the bread-making industry.

Multicriteria Pole Clustering and H2/Hinf Control of Regular Singular System

Zied Tmar,Mongi Besbes,Kamel Ben Slimane 제어·로봇·시스템학회 2024 International Journal of Control, Automation, and Vol.22 No.3

In this paper, a multicriteria control combining H2/Hin f techniques, and pole clustering under strictlinear matrix inequalities (LMI) solving is considered to achieve the design of a static state feedback controller. This robust control targets regular singular systems subject to uncertainties. We have studied the D-admissibility ofa pencil matrix, which is an extension of D-stability concept to singular systems, to formulate the clustering pole inLMI regions as an LMI optimization problem. In order to apply this control synthesis strategy, a methaniser processwith complex nonlinear model is used. A multivariable representation of an AM2 model for this biological processis determined to study governability. A transformation of the same AM2 model into a singular form allows to studythe controllability of the slow and fast subsystems and check the regularity of the system. The simulation results ofthe controlled methane flow rate shows an important improvement during the methanization phase.

Design of an Integrated Inductor with Magnetic Core for Micro-Converter DC-DC Application

Yassin Dhahri,Sami Ghedira,Kamel Besbes 한국전기전자재료학회 2016 Transactions on Electrical and Electronic Material Vol.17 No.6

This paper presents a design procedure of an integrated inductor with a magnetic core for power converters. Thisprocedure considerably reduces design time and effort. The proposed design procedure is verified by the developmentof an inductor model dedicated to the monolithic integration of DC-DC converters for portable applications. Thenumerical simulation based on the FEM (finite elements method) shows that 3D modeling of the integrated inductorallows better estimation of the electrical parameters of the desired inductor. The optimization of the electricalparameter values is based on the numerical analysis of the influence of the geometric parameters on the electricalcharacteristics of the inductor. Using the VHDL-AMS language, implementation of the integrated inductor in a microBuck converter demonstrate that simulation results present a very promising approach for the monolithic integrationof DC-DC converters.

An Improved Polytopic Adaptive LPV Observer Design Under Actuator Fault

Radhia Houimli,Neila Bedioui,Mongi Besbes 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.1

In this paper, we treat the problem of both state estimation and fault detection of nonlinear systems. Those systems could be described by a poly-quadratic Linear Parameter-Varying (LPV) form. A new adaptive observer is developed in terms of Linear Matrix Inequalities (LMI) technique. A feasible algorithm is developed to compute the designed parameters. This algorithm provides more flexibility and mitigates the conservatism of quadratic approach. Finally, simulation results are presented to illustrate the efficiency of the proposed method.

The Role of a Wiring Model in Switching Cell Transients: the PiN Diode Turn-off Case

Jedidi, Atef,Garrab, Hatem,Morel, Herve,Besbes, Kamel The Korean Institute of Power Electronics 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.2

Power converter design requires simulation accuracy. In addition to the requirement of accurate models of power semiconductor devices, this paper highlights the role of considering a very good description of the converter circuit layout for an accurate simulation of its electrical behavior. This paper considers a simple experimental circuit including one switching cell where a MOSFET transistor controls the diode under test. The turn-off transients of the diode are captured, over which the circuit wiring has a major influence. This paper investigates the necessity for accurate modeling of the experimental test circuit wiring and the MOSFET transistor. It shows that a simple wiring inductance as the circuit wiring representation is insufficient. An adequate model and identification of the model parameters are then discussed. Results are validated through experimental and simulation results.

The Role of a Wiring Model in Switching Cell Transients

Atef Jedidi,Hatem Garrab,Herve Morel,Kamel Besbes 전력전자학회 2017 JOURNAL OF POWER ELECTRONICS Vol.17 No.2

Power converter design requires simulation accuracy. In addition to the requirement of accurate models of power semiconductor devices, this paper highlights the role of considering a very good description of the converter circuit layout for an accurate simulation of its electrical behavior. This paper considers a simple experimental circuit including one switching cell where a MOSFET transistor controls the diode under test. The turn-off transients of the diode are captured, over which the circuit wiring has a major influence. This paper investigates the necessity for accurate modeling of the experimental test circuit wiring and the MOSFET transistor. It shows that a simple wiring inductance as the circuit wiring representation is insufficient. An adequate model and identification of the model parameters are then discussed. Results are validated through experimental and simulation results.

Optimization of Aspergillus oryzae S2 α-amylase, ascorbic acid, and glucose oxidase combination for improved French and composite Ukrainian wheat dough properties and bread quality using a mixture design approach

Mouna Sahnoun,Mouna Kriaa,Souhail Besbes,Mohamed Jardak,Samir Bejar,Radhouane Kammoun 한국식품과학회 2016 Food Science and Biotechnology Vol.25 No.5

A simplex-centroid experimental design was used for the optimization of both reducing and oxidizing improvers, namely Aspergillus oryzae S2 α-amylase (Amy), ascorbic acid (Asc), and glucose oxidase (GOD). This optimization was performed to enhance the dough and breadmaking qualities of soft French wheat flour and a composite counterpart that contained 30% Ukrainian wheat flour. Statistically significant correlations were calculated between the W index and textural parameters (e.g., dough chewiness and bread cohesiveness). The findings revealed that while the best mixture for French flour comprised 21.8% of Amy, 41.2% of Asc, and 37% of GOD, for the composite counterpart, it comprised 2.3% of Amy, 66% of Asc, and 31.7% of GOD. These optimized mixtures rearranged soft French wheat flour and its composite counterpart to a good quality and an improved flour texture, respectively. Additionally, they increased the loaf specific volumes of the breads made from soft French wheat flour and its counterpart by 25.8 and 45.43%, respectively, significantly decreased the breads’ susceptibility to microbial contamination, and reclassified the breads as “good” in terms of sensory attributes.