AJET_Vol 04 N 01
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Item Synthesis, characterization and antimicrobial studies on Mn(II), Fe(II), Co(II) complexes of schiff base derived from 3-Formylchromone and Benzohydrazide(جامعة الوادي - university of el oued, 2021-02-20) Hussaina, Aminu Ibrahim; Habu, Nuhu Aliyu; Musa, Husaini; Aysha, Salees DayyibSchiff base formed by condensation of 3-formylchromone and benzohyrazide and its metal(II) complexes of Mn(II), Fe(II), and Co(II), have been prepared and characterized by conductivity measurement, magnetic susceptibility, IR Spectra, atomic absorption spectroscopy, elemental analysis, as well as melting point/decomposition temperature and solubility test. The melting point of the Schiff base (165 0C) and decomposition temperatures of the complexes (185-198)0C indicating their thermal stability. The molar conductivity measurement determined are in the range (10.54-23.10) Ω-1cm2mol-1 revealing that all the complexes are non-electrolytic in nature. IR spectra of the Schiff base showed a band at 1633cm-1 which assigned to ʋ(-C=N-) stretching vibration. This band was observed downfield in the range (1603 -1655) cm-1 in the spectra of the metal(II) complexes revealing that the Schiff base formed metal complexes with the metal ions. The gram magnetic susceptibility measurements of the complexes showed that all the complexes except that of Zinc are paramagnetic and have tetrahedral geometry. The elemental analysis suggested a metal to ligand ratio of 1:1. The Schiff base and its metal complexes have been screened for their antimicrobial activity against four pathogens. Some compounds were active, while others are not active against the isolatesItem Statistical analysis and Response Surface Modelling of the compressive strength inhibition of crude oil in concrete test cubes(جامعة الوادي - university of el oued, 2021-04-03) Sebastian, AzowenuNwose; Francis, Odikpo Edoziuno; Sylvester, OsujiThe use of crude oil contaminated fine aggregates in the production of concrete significantly affect the properties of such concrete, especially the compressive strength. In the present investigation, response surface methodology (RSM) of the Design-Expert software version 11.1.0.1 was used for the statistical analysis and predictive modelling of the compressive strength of concrete cubes made from crude oil contaminated fine aggregates at 7, 14, 28, and 56 days curing periods. The fine aggregates were mixed with varying concentrations of crude oil contamination (ranging from 0% to 5% by weight of the fine aggregates, at 1% interval). Concrete test cubes were produced for compressive strength determination and prediction phase of the modelling. A steady reduction in the compressive strength of the concrete cubes was recorded as the crude oil content increases, due to the inhibitive and surface shielding influence of crude oil molecules on the fine aggregates, thereby hindering physical bond formation between the cement paste and the aggregates. Statistical analysis of the output/response was carried out; a correlation coefficient of 0.9923 was obtained. The result of the modelling has shown that the use of RSM is adequate in the prediction of the compressive strength inhibition of crude oil in concrete made from crude oil-contaminated sandItem Indirect effect of Covid-19 on Vegetation Indices around the cement plant of Gabes region(جامعة الوادي - university of el oued, 2021-03-08) Ben Atia, Zrouga Khaoula; Ben Amor, Afef; Dridi, Almohandes Bouthaina; Khebour Allouche, FaizaTo contain the Covid-19 pandemic, Tunisia imposed a national lockdown at the end of March 2020, a decision that resulted in a massive industrial complexes shutting down. The cement industry of Gabes was one of these complexes. However, to assess the impact of Covid-19 on the state of the vegetation around this industry three radiometric vegetation indices (RIs), NDVI, SAVI and EVI, were calculated from two Sentinel-2A imageries extracted at 22th December 2018 and 16th December 2020. Six plant species such as Oleo europaea, Ficus caria, Medicago sativa, Prunus persica vulgaris, Zygophyllumalbum and Helianthemum kahiricum were collected from 30 sites. Results suggest that, the period of pre-outbreak has the lowest averages of RIs. While, the after outbreak date has the higher levels of RIs presenting especially perennial species such as Oleo europaea. Then, EVI was the most higher index comparing to the rest of indices whatever the year studied. It was the most sensitive to cement dust and more susceptible to detect defoliation. Finally, through a remote application (RIs), the period of confinement allowed to improve the state of the vegetation surrounding the cement plant. It has helped the ecosystem to regenerate, especially perennial plant species.Item Hexavalent chromium removal from simulated wastewater using biomass-based activated carbon: kinetics, mechanism, thermodynamics and regeneration studies(جامعة الوادي - university of el oued, 2021-01-21) Yunusa, Umar; Kubo, Abdulrahman Ibrahim; Abdullahi, Yusuf; Abdullahi, Tahir; Husaini, MusaIn this study, activated carbon (ACBA) was fabricated from Balanites aegyptiaca seed shell (BASS) using a two-step H3PO4 activation approach and was tested for the adsorption of toxic hexavalent chromium [Cr(VI)] from simulated wastewater. The surface properties, morphology, and elemental composition of the prepared ACBA were examined via Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) surface area analyses. The influence of various operating conditions such as pH, adsorbent amount, contact time and temperature was investigated. Kinetic studies indicated that the pseudo second order model was able to provide a realistic description of the adsorption kinetics and that film diffusion was the dominating mechanism of the sorption process. The adsorption activation energy evaluated using kinetic data suggested physical nature of Cr(VI) adsorption onto the carbon surface. Thermodynamic investigation confirmed that the adsorption was spontaneous and endothermic in nature. Regeneration tests demonstrated that 0.2 M NaOH can appreciably desorb Cr(VI) from Cr(VI)-loaded ACBA and the regenerated adsorbent can be used for six successive adsorption-desorption cycles while sustaining an adsorption efficiency of 80.10%. Altogether, the ACBA showed high adsorptive performance, fast kinetics and reuse potential, indicating the suitability of its application in wastewater treatmentItem Geotechnical properties of some selected lateritic soils stabilized with cassava peel ash and lime(جامعة الوادي - university of el oued, 2020-11-27) Ayodele, Adekemi L; Mgboh, Chinedu V; Fajobi, Adeyemi BThis study presents the influence of cassava peel ash (CPA) and lime on some geotechnical properties of three lateritic soils. This is with a view to the use of locally available agricultural waste in stabilising lateritic soils. Soil samples (termed A, B, and C) were collected from three different locations in Osun state, South West, Nigeria. Some properties such as particle size distribution, liquid limit (LL), plastic limit (PL), Compaction properties (optimum moisture content, OMC and Maximum dry density, MDD), California bearing ratio (CBR) and unconfined compressive strength (UCS) of the soil samples were determined. Cassava peel collected from a cassava processing factory was calcined at 700oC and CPA produced was sieved through sieve No. 40. Different percentages, 2, 4, 6, 8% (by weight of dry soil) of CPA and a fixed percentage (4%) of lime were mixed with the lateritic soil. Lime was added to supply calcium ion (Ca2+) needed for formation of Calcium Silicate stabilising compounds. The LL, PL, OMC, MDD, CBR and UCS of the stabilised soil samples were determined. There was a general improvement in the geotechnical properties of the soil (especially samples A and B) with about 20% reduction in LL, 38% increase in CBR, 120% increase in UCS. The study revealed that a combination of CPA and lime has the potential of improving the geotechnical properties of fine grained lateritic soilItem Experimental study of ECG signal transmission system via a coaxial cable line using Duty-Cycle Modulation(جامعة الوادي - university of el oued, 2021-01-27) Nguefack, Laurel Tatou; Pauné, Félix; Mbihi, MbihiThis paper presents the first real and well tested prototyping duty cycle modulation (DCM) signal transmission system. The experimented system is applied to the transmission of ECG signals. It consists of an ECG signal acquisition system, a duty cycle modulation transmitter, a coaxial cable transmission medium and finally a simple low-pass filter as receiver. After a brief review of the literature highlighting the interest of this experiment, we analytically developed different parts of the proposed system. The experimental workbench and main results obtained are presented. These yield very good results since in addition to the high quality of ECG signal reconstitution, we manage to eliminate the power line interference induced during transmission. These results experimentally confirm the feasibility as well as new perspectives of using the proposed systems as a simple remote biomedical instrumentItem Experimental and quantum chemical investigation for the single and competitive adsorption of cationic dyes onto activated carbon(جامعة الوادي - university of el oued, 2021-01-04) Yunusa, Umar; Usman, Bishir; Ibrahim, Muhammad BashirSingle and competitive adsorption studies were performed to scrutinize the removal of two cationic dyes, namely, crystal violet (CV) and malachite green (MG) by adsorption onto activated carbon (BAC) derived from Balanites aegyptiaca seed shell. The BAC was characterized via scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and pH of point of zero charge (pHpzc) analysis. The physicochemical parameters influencing the adsorption process, namely, pH, contact time, adsorbent weight, initial concentration, temperature and ionic strength were examined. Moreover, Density Functional Theory (DFT) studies were performed to investigate the chemical reactivity of the dye molecules. Experimental results indicated that maximum adsorption of both dyes was achieved at pH 8.0 and equilibrium was attained after contact time of 50 min for MG and 60 min for CV. The competitive adsorption results showed lower adsorption capacities as compared to the single adsorption results indicating antagonistic interaction. Isotherm and kinetic models were employed for fitting the experimental data. The sorption kinetics was found to obey the pseudo second order model. The equilibrium data suggests that Freundlich model could represent the dyes uptake onto the adsorbent. Thermodynamic analysis revealed that the adsorption is a spontaneous and endothermic process. The quantum chemical investigation performed on the tested dyes using DFT method have affirmed that the MG molecules are more reactive (ΔE = 1.236 eV), electrophilic and have the capacity to adsorb strongly on the BAC surface compared to the CV (ΔE = 1.476 eV). The results attested that BAC has great potential for cationic dyes adsorption from aqueous environment.Item Experimental and quantum chemical investigation for the single and competitive adsorption of cationic dyes onto activated carbon(جامعة الوادي - university of el oued, 2021-01-04) Yunusa, Umar; Usman, Bishir; Ibrahim, Muhammad BashirSingle and competitive adsorption studies were performed to scrutinize the removal of two cationic dyes, namely, crystal violet (CV) and malachite green (MG) by adsorption onto activated carbon (BAC) derived from Balanites aegyptiaca seed shell. The BAC was characterized via scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and pH of point of zero charge (pHpzc) analysis. The physicochemical parameters influencing the adsorption process, namely, pH, contact time, adsorbent weight, initial concentration, temperature and ionic strength were examined. Moreover, Density Functional Theory (DFT) studies were performed to investigate the chemical reactivity of the dye molecules. Experimental results indicated that maximum adsorption of both dyes was achieved at pH 8.0 and equilibrium was attained after contact time of 50 min for MG and 60 min for CV. The competitive adsorption results showed lower adsorption capacities as compared to the single adsorption results indicating antagonistic interaction. Isotherm and kinetic models were employed for fitting the experimental data. The sorption kinetics was found to obey the pseudo second order model. The equilibrium data suggests that Freundlich model could represent the dyes uptake onto the adsorbent. Thermodynamic analysis revealed that the adsorption is a spontaneous and endothermic process. The quantum chemical investigation performed on the tested dyes using DFT method have affirmed that the MG molecules are more reactive (ΔE = 1.236 eV), electrophilic and have the capacity to adsorb strongly on the BAC surface compared to the CV (ΔE = 1.476 eV). The results attested that BAC has great potential for cationic dyes adsorption from aqueous environmentItem Electrodeposition of CaCO3 on stainless steel 316 L substrate: influence of thermal-hydraulics and electrochemical parameters(جامعة الوادي - university of el oued, 2021-04-14) Amzert, Sid Ahmed; Arbaoui, Fahd; Boucherit, Mohamed Nadir; Selmi, Noureddine; Salah, HaniniIn this paper we study the effect of the hardness, the rotation speed, the temperature and the cathodic polarization on calcium carbonate scale deposit on rotating stainless steel electrode using electrochemical techniques. The scale deposit was investigated by X-Ray diffraction, scanning electron microscope, Infrared spectroscopy and electrochemical impedance spectroscopy (EIS). The electrochemical results show that the Oxygen Reduction Reaction (ORR), which is responsible of CaCO3 electrodeposition, takes place with 4 electrons at low rotation speed lower than 600 rpm and 2 electrons at high rotation speed upper to 1000 rpm. The recovery times of concentrations: 100, 300 and 600 mg/L are respectively 2.0 h 20 min, 1 h 20 min and 1 h. The morphology of the CaCO3 scale deposit shows that the crystals formed in the center of the electrode have small sizes compared to those of the periphery. Whatever the hydrodynamic or thermodynamic conditions, the Calcite form remains predominant. Other forms appear in particular conditions: at high temperature up to 50°C the aragonite form and at high cathodic polarization about -1.2 V/SCE the vaterite form.Item Corrosion inhibition effect of benzaldehyde (Methoxybenzene) for Aluminium in sulphuric acid solution(جامعة الوادي - university of el oued, 2020-11-13) Abdullahi, Ayuba; Muhammad, AbubakarCorrosion inhibitory effect of benzaldehyde (methoxybenzene) on aluminium in sulphuric acid media was studied by weight loss measurement and characterization was carried by FTIR analysis. From the results it was found that increase in inhibitor concentration lead to the increase in inhibition efficiency and decreases when the temperature increased. Plots of ln (wi - Δw) against time gave a linear graphs which confirmed a first order reaction mechanism for aluminium in inhibited and uninhibited acid solution. The activation energy value of uninhibited acid solution was found to be 36.39 kJ/mol which increased to 62.32 kJ/mol when 0.1 M concentration of the inhibitor was added. There was a decreased in the values of the rate constant from uninhibited to inhibited acid solution while those of half-life increased from uninhibited to inhibited acid. The obtained values of entropy change (ΔS), enthalpy change (ΔH) and Gibbs free energy of adsorption (ΔGads) were also evaluated and discussed. The activation energy values and that of Gibbs free energy of adsorption support the physisorption mechanism between the molecules of the inhibitor and Aluminium surfaceItem A new design of square paralelipedic treatment chamber for food processing using pulsed electric field(جامعة الوادي - university of el oued, 2021-02-25) Bellebna, Yassine; Ramdani, Nadia; Khalfi, Yassine; Tilmatine, AmarToday, the influence of pulsed electric field is one of the key components in the PEF treatment process. The manuscript focused on the design and development of new multiple square paralelipedic PEF treatment chamber (TC2) which houses several electrodes, and testing the efficacy of this chamber on beet juice extraction compared with a single square paralelipedic treatment chamber (TC1) which houses only two electrodes. The aim of this paper to mention the effect of the Electric Field distribution based on Response Surface Modeling (RSM) for identifying the set point of the juice extraction process using pulsed electric field pre-treatment using a laboratory experimental bench. Obtained results show that the TC2 of PEF treatment has significant effect not only in juice yield, but also for enhancement of the betanin concentration and saving in consumed energyItem A new design of square paralelipedic treatment chamber for food processing using pulsed electric field(جامعة الوادي - university of el oued, 2021-02-25) Bellebna, Yassine; Ramdani, Nadia; Khalfi, Yassine; Tilmatine, AmarToday, the influence of pulsed electric field is one of the key components in the PEF treatment process. The manuscript focused on the design and development of new multiple square paralelipedic PEF treatment chamber (TC2) which houses several electrodes, and testing the efficacy of this chamber on beet juice extraction compared with a single square paralelipedic treatment chamber (TC1) which houses only two electrodes. The aim of this paper to mention the effect of the Electric Field distribution based on Response Surface Modeling (RSM) for identifying the set point of the juice extraction process using pulsed electric field pre-treatment using a laboratory experimental bench. Obtained results show that the TC2 of PEF treatment has significant effect not only in juice yield, but also for enhancement of the betanin concentration and saving in consumed energy