M. DJEMLI Amar

This study presents the development of a high-sensitivity surface plasmon resonance (SPR) sensor featuring an innovative structure composed of a BK7 prism glass, copper (Cu) thin film, titanium dioxide (TiO₂), nickel (Ni), and a two-dimensional black phosphorus (BP) layer combined with a sensing medium. The sensor utilizes an angular interrogation technique, with its performance parameters sensitivity (S), detection accuracy (DA), and quality factor (QF) analyzed using the attenuated total reflection (ATR) and transfer matrix method (TMM). The results demonstrate significant improvements in the full-width at half-maximum (FWHM), detection accuracy, quality factor, and sensitivity due to the hybrid TiO₂, Ni, and BP layers. The impact of copper thickness is also thoroughly investigated. The study identifies optimal sensor performance with a sensitivity of 518°/RIU and a quality factor of 91.51/RIU, achieved with optimized thicknesses of 35 nm (Cu), 2 × 4 nm (TiO₂), 10 nm (Ni), and 0.53 nm (BP). Furthermore, an alternative configuration yields even higher sensitivity, achieving 526°/RIU and a quality factor of 96.51/RIU, with a copper thickness of 35 nm, TiO₂ thickness of 2 × 2 nm, and nickel thickness of 15 nm. The enhanced sensitivity and performance of the TiO₂, Ni, and BP hybrid layers suggest their promising applicability in diverse biosensing scenarios. This study highlights the potential of this optimized SPR sensor configuration for advanced biosensing applications, owing to its high sensitivity and improved quality factor.

Water-crude oil emulsion causes challenges, which the petrochemical sector solves using efficient, ecologically friendly, and cost-effective demulsifying chemicals. With this work, we aim to solve the problem of the presence of water in Algerian oil after it has left the producing well by adding a natural material, widely used in the country, as an environmentally friendly demulsifier. Atriplex halimus L. leaf ATP powder (ATP-P) and leaf extract (E-ATP) were studied. We first characterized the two biosurfactants ATP-P and E-ATP by attenuated total reflectance (ATR), X-ray diffraction (XRD), and thermogravimetry analysis (TGA). The effect of ATP-P and E-ATP on the emulsion (water/oil) was studied by Fourier transform infrared spectroscopy (FTIR) analysis, microscopic, rheological behavior, interfacial tension (IFT), and bottle tests. The results obtained show the ability of the two biosurfactants E-ATP and ATP-P to separate water, with water separation reaching 99% in 30 minutes with 500 ppm of E-ATP, while ATP-P separates 98% in 92 minutes. The mechanism of action of the two compounds as biodemulsifiers can be traced back to the rheological study, which showed a 33% reduction in emulsion viscosity at 500 ppm; ATR-FTIR analysis also shows the disappearance of carbon-carbon and carbon-oxygen bonds, responsible for the reduction in oil viscosity. A decrease in surface tension by 41.48% by adding P-ATP and 57.95% by adding E-ATP contributed to the integration of water molecules and increased separation speed. Microscopic analysis shows an increase in the volume diameter of the water droplets, more than threefold when E-ATP is added and more than twofold when ATP-P is added.

The synthesis of forsterite can be challenging because the initial oxides react slowly and undesirable compounds like enstatite (MgSiO3) can form instead of forsterite (Mg2SiO4). Although several methods have been developed to overcome these challenges, the synthesis of forsterite using the solid-state reaction of nanopowders has not been investigated. This study aims to explore the possibility of producing forsterite by reacting MgO and SiO2 nano-powder. The initial oxides were wet ball milled, dried, and reaction sintered. Spectroscopy and microscopy methods were used to analyze the formed phases and study the formation kinetics. The density, coefficient of thermal expansion (CTE), and hardness of sintered samples were measured using a densimeter, a dilatometer, and a hardness tester, respectively. The results demonstrated that it is possible to synthesize forsterite by solid state reaction of pure MgO and SiO2 nano-powders. The reaction between the two compounds begins at a temperature as low as 860 °C and leads to the formation of forsterite by a two-step formation mechanism. The first reaction involves the reaction of MgO and SiO2 to form enstatite, and the second one produces forsterite as a result of enstatite reacting further with MgO. The activation energy values ranged from 1028.89 to 1105.655 kJ/mol for the formation of forsterite, and from 456.316 to 488.08 kJ/mol for the formation of enstatite. Monolithic forsterite was completely formed at a low temperature of 1200 °C for a relatively short duration of 2 h. The sample sintered at 1400 °C for 2 h, had a density of 2.96 g/cm3, a Vickers hardness of 7.64 GPa, and a coefficient of thermal expansion of 10.24 × 10−6/K measured in the temperature range of 200–1300 °C.

This paper studies a novel surface plasmon resonance (SPR) biosensor using a BK7 glass prism, a copper (Cu) metal plasmonic layer, which combine a halide perovskite (FASnI3) with two-dimensional (2D) materials such as phosphorus black, graphene and TMDC (MoS2, MoSe2, WS2, WSe2) for the detection of breast cancer cells. We have optimized the thickness of each layer in order to obtain maximum sensitivity. A numerical study mainly uses the transfer matrix principle, while the attenuation total reflection method involves examining the reflection properties. The evaluation of SPR biosensor configurations serves to obtain optimal performance. The simulation results indicate that the integration of halide perovskite (FASnI3) and 2D materials into the BK7/Cu/medium sensing structure significantly improves the sensitivity and figure of merit (ZT). The outstanding results in terms of sensor performance characteristics are observed in the BK7/Cu (48 nm)/FASnI3 (5 nm)/BP (0.53 nm) configuration. The figure of merit and sensitivity estimated at 123.11 RIU−1 and 459.28°/RIU, with a notable improvement of 338.45 %.

This study presents a novel structure to improve the SPR biosensor’s sensitivity that is employed for tuberculosis detection. The structure consists of five layers: CsF prism glass, silver thin film, Pd and the material 2D TaSe2 layer with sensing medium, it uses an angular interrogation technique. Attenuated total reflection (ATR) and the transfer matrix method (TMM) are used to investigate the highly performance parameters of the biosensors in terms of sensitivity (S), detection accuracy (DA) and figure of merit (FOM). The result of the research is that the sensitivity of the Pd and TaSe2 hybrid layer is improved, and the full half maximum also increased but decreased in (DA) and (FOM) values. The hybrid Pd and TaSe2 layer improved sensitivity, the full-at-half maximum has also increased but decreased (DA) and (FOM) values. Analysis of silver thickness effect is also investigated. The highest sensitivity is obtained at 410°/RIU with optimized thicknesses of Ag, Pd, and TaSe2 of 40 nm, 15 nm, and 1 nm, respectively. The proposed SPR biosensor looks promising for use in various biosensing applications.

The main objective of this research is the explanation of the replacement of feldspar limestone imported from Spain with recycled automotive glass, in order to reduce waste and promote environmental sustainability. Details and efforts of making porcelain ceramics from local raw materials such as quartz, kaolin and glass are also given. Replacing the feldspar with reclaimed automotive glass shows the effect of the Na2O and CaO solvents contained in the glass on the sintering and crystallization of the studied porcelain. The results showed that the added glass contributes to the reduction of the density and the acceleration of the sintering process, by occupying the sites of the open spaces, observed in the samples not containing feldspars. By reaching a nonporous ratio at a temperature of 1000∘C, the melting of the material is accelerated due to the dissolved oxides it contains, in addition to the linear shrinkage rate in samples that contain a lot of glass reaching the normal level of porcelain (about 12%) at low temperature compared to ordinary porcelain.

Kinetics, Phase Transformations and Sintering of Mg-doped LaMnO3
Foudil SAHNOUNE1, Amar DJEMLI1, Abdelmadjid BOUSSENDEL1, Essebti Dhahri2, and Nouari Saheb3
1physics and materials chemistry laboratory, Department of Physics, University of M’sila, 28000 M’sila, Algeria
23Laboratoire de Physique Appliquée, Faculté des Sciences, Université de Sfax, B.P.1171, 3000 Sfax, Tunisia
3Dep. of Mechanical Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia
Abstract
Lanthanum manganite (LaMnO3) is a complex oxide compound with various applications in wide fields, including solid oxide fuel cells, magnetic and electronic devices, catalysts, and multiferroics. Several available methods were used by researchers to prepare LaMnO3 such as solid-state synthesis, sol-gel method, hydrothermal synthesis, co-precipitation method, and assisted microwave synthesis, choosing a method depends on several factors, like desired particle size, morphology, purity, crystal structure of the LaMnO3, and the availability of resources and equipment.
This study investigated the kinetics of LaMnO3 doped with magnesium ceramics synthesized using sol-gel method and starting materials as lanthanum nitrate (La (NO3)3*6H2O), manganese nitrate (Mn(NO3)2*6H2O), Magnesium nitrate (Mg(NO3)2*6H2O), and citric acid monohydrate (C6H8O7*H2O). In order to characterize the results, various techniques were used, including thermogravimetry (TG), differential thermal analysis (DTA), and X-ray powder diffraction (XRD). The activation energy (Ea) of La0.7Mg0.3MnO3 phase formation was measured by heat treating the sample up to 600 °C in various rates (0.3, 0.5, 0.7, and 1 °C/min) using differential thermal analysis (DTA). Using Kissinger, Boswell, and Ozawa methods Ea values were calculated and found to be 184, 189, and 185 kJ/mol, respectively.
Both the growth morphology parameter n and the dimension of crystal growth m were determined to be approximately 1.5, suggesting that bulk nucleation with a constant number of nuclei was the dominant mechanism in La0.7Mg0.3MnO3 crystallization, which was followed by one-dimensional growth controlled by interface reaction. The tracking of the phase Transformations done by DTA at different temperatures (260, 400, 700, and 1100 °C) were analyzed using X-ray diffraction. Additionally, we analyzed the material's structural properties at different sintering temperatures (700, 800, 900, 1000, and 1100 °C) for 4 hours. Finally, we examined the changes in the crystal dimension of the material in consideration of both temperature and time.
Keywords: Phase Transformations, activation energy, Sintering, crystallization kinetics
 Corresponding Author Email: foudil.sahnoune@univ-msila.dz

Lanthanum Manganite LaMnO3 Crystallization Kinetics Prepared Through Sol-Gel Auto-Combustion Method

Abdelmadjid BOUSSENDEL1, Amar DJEMLI1, Foudil SAHNOUNE1, 2

1physics and materials chemistry laboratory, Department of Physics, University of M’sila, 28000 M’sila, Algeria
2Research Unit on Emerging Materials (RUEM), Ferhat Abbas of Setif 01, Setif 19000, Algeria


Abstract

This study focused on the synthesizing, phase transformation, and sintering behavior of Lanthanum manganite (LaMnO3), and the importance of such material due to its imbedded potential applications in various fields, including catalysis, energy storage, and solid oxide fuel cells. The sol-gel auto-combustion method was used in the preparation of the LaMnO3 sample, Sol-Gel method is known to it superior qualities such as high purity, homogeneous materials, and the ability to control particle size and morphology. The investigation of LaMnO3 sample phase transformation and sintering behavior was done in this study using several analytical techniques, thermogravimetry (TG), differential thermal analysis (DTA), and X-ray diffraction (DRX) analysis. In order to describe the energy barrier required for a particular process to occur such as a phase transformation or a chemical reaction, the activation energy (EA) for the phase transformation was calculated using three different methods: The Kissinger, Boswell, and Ozawa method. EA value was determined to be 173.8, 184, and 170 kJ/mol, respectively. which provides important information about the energy requirements for the phase transformation to occur for LaMnO3 materials, this information is extremely useful in the conditions of the process throughout designing and optimizing. The parameters that describe the reaction mechanism and the rate of the process are called kinetic parameters of Avrami n and m, which were calculated and found to be approximately 1.5. Overall, this study is essential because it provides insightful scope into the phase transformation and sintering behavior of LaMnO3.

Keywords: differential thermal analysis, Phase Transformations, activation energy, crystallization kinetics


 Corresponding Author Email: abdelmadjid.boussendel@univ-msila.dz