The satisfaction rate of desired velocity in the case of a mixture of fast and slow vehicles is studied by using a cellular automaton method. It is found that at low density the satisfaction rate depends on the maxima...The satisfaction rate of desired velocity in the case of a mixture of fast and slow vehicles is studied by using a cellular automaton method. It is found that at low density the satisfaction rate depends on the maximal velocity. However, the behavior of the satisfaction rate as a function of the coefficient of variance is independent of the maximal velocity. This is in good agreement with empirical results obtained by Lipshtat [Phys. Rev. E 79 066110 （2009）]. Furthermore, our numerical result demonstrates that at low density the satisfaction rate takes higher values, whereas the coefficient of variance is close to zero. The coefficient of variance increases with increasing density, while the satisfaction rate decreases to zero. Moreover, we have also shown that, at low density the coefficient variance depends strongly on the probability of overtaking.展开更多
A better understanding of the geology and mineral potential of Africa is important in the overall context of social and economic development across the continent. Since 1995 the Association of African Women Geoscienti...A better understanding of the geology and mineral potential of Africa is important in the overall context of social and economic development across the continent. Since 1995 the Association of African Women Geoscientists （AAWG） has existed, holding biennial meetings since 2002, with the aim to encourage women geoscientists to participate in Earth Sciences-related conferences, as well as to inform or become involved on gender issues related to the Earth Sciences.展开更多
Two new compounds 7-hydroxy-5-O-（β-D-glucopyranoside） flavan （1） and （Z）-4＇,6＇-dihydroxy-2＇-O-（β-D-glucopyranoside） chalcone （2）, along with eight known compounds, were isolated from the stem bark of Dr...Two new compounds 7-hydroxy-5-O-（β-D-glucopyranoside） flavan （1） and （Z）-4＇,6＇-dihydroxy-2＇-O-（β-D-glucopyranoside） chalcone （2）, along with eight known compounds, were isolated from the stem bark of Drypetes parvifolia （Euphorbiaceae）. Their structures were established on the basis of spectroscopic analysis and chemical evidence.展开更多
This paper introduces a novel variant of particle swarm optimization that leverages local displacements through attractors for addressing multiobjective optimization problems. The method incorporates a square root dis...This paper introduces a novel variant of particle swarm optimization that leverages local displacements through attractors for addressing multiobjective optimization problems. The method incorporates a square root distance mechanism into the external archives to enhance the diversity. We evaluate the performance of the proposed approach on a set of constrained and unconstrained multiobjective test functions, establishing a benchmark for comparison. In order to gauge its effectiveness relative to established techniques, we conduct a comprehensive comparison with well-known approaches such as SMPSO, NSGA2 and SPEA2. The numerical results demonstrate that our method not only achieves efficiency but also exhibits competitiveness when compared to evolutionary algorithms. Particularly noteworthy is its superior performance in terms of convergence and diversification, surpassing the capabilities of its predecessors.展开更多
Modeling experimental design was used to study the main effects and the interaction effects between operational parameters in the photocatalytic degradation of pesticide methomyl. The important parameters which affect...Modeling experimental design was used to study the main effects and the interaction effects between operational parameters in the photocatalytic degradation of pesticide methomyl. The important parameters which affect the removal efficiency of methomyl such as concentration of Fe(NO3)3, concentration of H2O2, initial concentration of the pesticide and pH. The parameters were coded as x1, x2, x3 and x4, consecutively, and were investigated at two levels (–1 and +1). The effects of individual variables and their interaction effects for dependent variables, namely, photocatalytic degradation efficiency (%) were determined. From the statistical analysis, the most effective parameters in the photocatalytic degradation efficiency were initial concentrations of the methomyl and Fe(NO3)3. The interaction between initial concentration of the pesticide and Fe(NO3)3 was the most influencing interaction. The optimum conditions that were obtained for the photocatalytic degradation of methomyl were: minimum quantity of contaminant: 6 × 10–5 mol.L–1, maximum quantity of Fe(NO3)3: 5 × 10–4 mol.L-1, initial pH of the solution: 3 and maximum quantity H2O2: 10–2 mol.L–1.展开更多
In this paper,we define new measures called respectively graph measure of noncompactness and graph measure of weak noncompactness.Moreover,we apply the obtained results to discuss the incidence of some perturbation re...In this paper,we define new measures called respectively graph measure of noncompactness and graph measure of weak noncompactness.Moreover,we apply the obtained results to discuss the incidence of some perturbation results realized in [2] on the behavior of essential spectra of such closed densely defined linear operators on Banach spaces.These results are exploited to investigate the essential spectra of a multidimensional neutron transport operator on L1 spaces.展开更多
Saline waters treatment has become increasingly important for drinking water supply in a greater part of the world. However, some serious limitations had recently been discovered during water treatment, among them the...Saline waters treatment has become increasingly important for drinking water supply in a greater part of the world. However, some serious limitations had recently been discovered during water treatment, among them the boron problem seems to have a critical meaning. According to the WHO regulations (2011), the boron concentration should be reduced to less than 2.4 mg/L for drinking water. The purpose of this study is to investigate the feasibility of electrocoagulation (EC) as a pretreatment process to remove boron from saline waters. To optimize the experimental conditions of boron removal, the effects of some parameters were studied such as inter-electrode distance (die), electrode connection mode, (S/V) ratio, pHi and initial conductivity of the solution (σi). Subsequently, an experimental design methodology was implemented to evaluate statistically the most significant operating parameters. The effects of current density, EC time and initial boron concentration and their mutual interaction were investigated using 23 full factorial design. At optimal conditions, boron removal from synthetic aqueous solutions containing initial boron concentrations of 5 and 50 mg/L reached 81% and 79%, respectively. Applied to boron removal from seawater samples, EC reduces boron concentration to less to 2.4 mg/L with excessive energy consumption under optimal parameters.展开更多
The purpose of this study was to evaluate the acute toxicity and sedative effect of the ethylic extract of Thymelaea lythroides (Tl) on Wistar rats. The study was based on the gavage administration of the ethylic extr...The purpose of this study was to evaluate the acute toxicity and sedative effect of the ethylic extract of Thymelaea lythroides (Tl) on Wistar rats. The study was based on the gavage administration of the ethylic extract of Tl with different doses (i.e. 200, 400, 500 and 5000 mg/kg), where the toxicity and the sedative activity of the plant were observed and the obtained results were analyzed using the ANOVA test followed by the Bonferroni test. The main results of this study showed that the lethal dose of the ethylic extract of Tl was higher than the 5000 mg/kg dose. Moreover, when compared to the control rats, the animals treated with 5000 mg/kg of the extract exhibited significant reduction in appetite for food and water in the first week. Furthermore, results of the psychotropic test conducted during this study showed visible effects on the exploratory activity of the rats. The dose of 5000 mg/kg was also found to have a significant central nervous system effect;the locomotor activities of the animals decreased in a manner similar to those administered with Zepam as control.展开更多
The objective of this project is the valorization of Mako andesitic volcanic tuffs for use in social housing in the Kedougou region. To achieve these objectives, a geotechnical characterization of the tuff samples was...The objective of this project is the valorization of Mako andesitic volcanic tuffs for use in social housing in the Kedougou region. To achieve these objectives, a geotechnical characterization of the tuff samples was carried out and the geopolymerization stabilization was adopted for the manufacture of bricks. These bricks stabilized by an alkaline activation offer compressive strengths that exceed the threshold value (2.9 MPa) set by the standard (NF P14-304). The best compressive strengths (12.14 MPa) and flexural tensile strengths (5.43 MPa) are obtained in the series of bricks made with 35% of the mass of a solution of caustic soda at 12 molars concentration with a curing temperature cooking of 185°C and an average absorbance of 13.21%.展开更多
An efficient and clean preparation of acylals from aromatic aldehydes in the presence of synthetic phosphates (flourapatite and hydroxyapatite doped with ZnCl2 and ZnBr2) and acetic anhydride was achieved easily in hi...An efficient and clean preparation of acylals from aromatic aldehydes in the presence of synthetic phosphates (flourapatite and hydroxyapatite doped with ZnCl2 and ZnBr2) and acetic anhydride was achieved easily in high yields (86% - 97%) at room temperature under solvent-free conditions. Deprotection of the resulting acylals has also been attained by using the same catalysts under microwave irradiation. This method consistently has advantage of excellent yields (82% - 96%) and a short reaction time (3 - 4 min).展开更多
Soil salinity, which affects more than 6% of the earth’s land surface and more than 20% of its irrigated areas, is a major threat to agriculture. Diazotrophic bacteria are among the functional groups of soil microbio...Soil salinity, which affects more than 6% of the earth’s land surface and more than 20% of its irrigated areas, is a major threat to agriculture. Diazotrophic bacteria are among the functional groups of soil microbiota that are threatened by this abiotic stress, as their activity is mostly inhibited by salt stress. Seventy bacterial strains with distinct characteristics were isolated from soils by using N-free Jensen’s selective medium. Based on their ability to produce metabolites of agricultural interest, four strains were selected and identified as Flavobacterium johnsoniae, Pseudomonas putida, Achromobacter xylosoxidans, and Azotobacter chroococcum. The selected strains were grown at different NaCl concentrations (0–600 mmol L^(-1) in N-free broth and 0–2 000 mmol L^(-1) in Luria-Bertani medium) in the presence and absence of glycine betaine (GB), aqueous and hydro-alcoholic extracts from marine macroalgae, Ulva lactuca and Enteromorpha intestinalis, and Opuntia ficus-indica cladodes. The selected bacterial strains, GB, and the aforementioned extracts were tested for their ability to promote the germination of wheat (Triticum durum) seeds at 0–300 mmol L^(-1) NaCl. Compared with the results obtained with the synthetic osmoprotectant GB, the extracts from O. ficus-indica, U. lactuca, and E. intestinalis significantly promoted bacterial growth and seed germination under salt stress.展开更多
In current report,the structural,magnetic,and thermoelectric properties of RE doped MgPm_(2)X_(4)(X=S,Se) spinels were investigated.The energy difference in ferromagnetic and antiferromagnetic states reveals the stabi...In current report,the structural,magnetic,and thermoelectric properties of RE doped MgPm_(2)X_(4)(X=S,Se) spinels were investigated.The energy difference in ferromagnetic and antiferromagnetic states reveals the stability of MgPm_(2)(S/Se)_(4) in the ferromagnetic states.The co mputation of enthalpy of formation also ascertains thermodynamic stability of crystal structure.Spin-dependent band structure and density of states analysis reveal ferromagnetic semiconducting character showing different electronic behavior in both spin channels.The room temperature ferromagnetism,spin polarization and Curie temperature are estimated from exchange energies analysis.In addition,exchange constants(N_(0)α and N_(0)β),exchange energy Δ_(x)(pd),crystal ifeld energy,and double exchange mechanism were studied to explore the magnetic response.Likewise,the electrical conductivity,thermal conductivity,Seebeck co-efficient,and power factor show effect on electrons spin and their potential for thermoelectric devices.展开更多
Several types of solid acid catalysts were prepared based on oxides like (ZrO2, TiO2, HfO2, MCM-41 and SBA-15), using two main preparation methods: the precipitation and the sol-gel methods. Each catalyst was subjecte...Several types of solid acid catalysts were prepared based on oxides like (ZrO2, TiO2, HfO2, MCM-41 and SBA-15), using two main preparation methods: the precipitation and the sol-gel methods. Each catalyst was subjected to two types of impregnations: sulfate ions using sulfuric acid as precursor and niobium using niobium oxalate as precursor. These prepared catalysts were tested in the etherification reaction of 2-naphtol, where the catalysts showed both acidic and redox properties. The acidic character was manifested through the formation of 2-butoxynaphtalene (with moderate yields) when oxide is sulfated, and the redox character (when impregnated with niobium) manifested through the formation of the interesting product 2-ethylnaphtofuran (with low yields) and other products that were a result of oxidative coupling of two 2-naphtol molecules (binol and acetal of binol). However despite the effort, several attempts to increase the yield of 2-ethylnaphtofuran did not work. All products prepared were obtained in pure form and characterized by 1H and 13C NMR, GC and MS.展开更多
Several types of solid acid catalysts were prepared based on oxides like (ZrO2, TiO2, HfO2, MCM-41 and SBA-15). Each catalyst was subjected separately to two types of impregnations: sulfate ions and niobium. The catal...Several types of solid acid catalysts were prepared based on oxides like (ZrO2, TiO2, HfO2, MCM-41 and SBA-15). Each catalyst was subjected separately to two types of impregnations: sulfate ions and niobium. The catalytic activity of these solids was tested in the oxidation reaction of 1-octanol. These catalysts showed acidic and redox characters. MCM-41 and SBA-15 materials showed higher redox catalytic activities through the formation of (octyl octanoate, peroxyacetal and octanal). Our interest was focused on obtaining the ester (octyl octanoate) with high yields.展开更多
The work aims to develop a process for freezing desalination of seawater on cold walls. The experiments were performed with water/NaCl solutions of different concentrations and with samples of seawater. The pilot crys...The work aims to develop a process for freezing desalination of seawater on cold walls. The experiments were performed with water/NaCl solutions of different concentrations and with samples of seawater. The pilot crystallizer consists of a cooled tube immersed in a cylindrical double jacketed tank containing water to be treated. The complete process of desalination is conducted in two steps： the freezing step, leading to the crystallization of the ice layer and the sweating step, which consists of purifying the ice layer in depth by melting the impure zones. The systematic study of the influence of operating parameters has highlighted the important role of the cooling ramp and salinity of the solution on the purity of the ice produced. In the absence of stirring, the temperature of the double jacket also has a noticeable effect on the purity of the ice due to temperature gradients, and consequently, convection currents that may result in the solution. The results of this work show the feasibility of the technique and give a good indication of operating conditions that can be used to produce drinking water.展开更多
Background: In most societies, homicide or murder is a crime that often leads to imprisonment. Studies around the world have sometimes found cases of mental illness (schizophrenia spectrum disorders) as an explanation...Background: In most societies, homicide or murder is a crime that often leads to imprisonment. Studies around the world have sometimes found cases of mental illness (schizophrenia spectrum disorders) as an explanation for some homicides. The aim of this study was to determine the factors associated with homicide in the Togolese context. Methods: This was a descriptive and analytical cross-sectional study of pre-trial psychiatric expertise reports from January 31<sup>st</sup>, 2019 to January 30<sup>th</sup>, 2022. Results: Out of 704 defendants appraised, 206 (29.3%) had committed homicide. Males accounted for 91.7% of Homicide defendants (HD). Their average age was 31.6 ± 12.2 years, with extremes of 16 and 74 years. Factors associated with homicide were female gender, age between 30 and 45 years, married or cohabiting status and occupation as a farmer/fisherman/breeder. Psychoactive substance use (PAS), mental illness and psychiatric history were not associated with homicide. Conclusion: Preventing delinquency and interpersonal conflict, and promoting social cohesion, could significantly reduce homicides in Togo.展开更多
The Design of Experiments (DOE) and the Analysis of Variance (ANOVA) are used to determine the effect of fuel type, fuel initial load, secondary air inlet and ventilation on thermal efficiency and CO emission of two b...The Design of Experiments (DOE) and the Analysis of Variance (ANOVA) are used to determine the effect of fuel type, fuel initial load, secondary air inlet and ventilation on thermal efficiency and CO emission of two biomass fire cookstoves during boiling or simmering. Analysis of variance with Fischer’s statistical test (F-test) and Newman-Keuls test were applied to establish the influence of the independent parameters on the studied responses. The results of this study are useful to application of charcoal cooks stoves.展开更多
Thanks to detailed field investigations, microstructural and geochemical analysis and relationship with enclosing rocks, microfabrics, magmatic typology and metamorphic evolution of the Kantè sepentinites have be...Thanks to detailed field investigations, microstructural and geochemical analysis and relationship with enclosing rocks, microfabrics, magmatic typology and metamorphic evolution of the Kantè sepentinites have been specified for the first time. The Kantè serpentinites in northern Togo constitute a mega-lens of ultrabasic rocks tectonically intercalated in the sericite chlorite schists of the Atacora structural unit. The brecciated, schitotose or massive rock facies are strongly marked by an S1 schistocity plane superimposed by a flat C shear plane linked to a west vergence thrusting movement. The parageneses that compose the metamagmatites are essentially serpentinous, containing plagioclase, opaque minerals (magnetite, chromite, spinel) and pyroxene porphyroblasts. These microfabrics represent relics of a probable gabbroic protolith. In fact, the geochemical characteristics of the Kantè serpentinites suggest that their magmatic typology is that of komatiites or tholeiitic basalts with oceanic arc affinities. They would have been emplaced in an active margin environment. The retromorphic evolution of the protolith corresponds to the phase of involvement in a major tangential contact during the panafrican tectogenesis.展开更多
<span style="font-family:Verdana;">The use of </span><i><span style="font-family:Verdana;">Ch</span></i><i><span style="font-family:Verdana;"&...<span style="font-family:Verdana;">The use of </span><i><span style="font-family:Verdana;">Ch</span></i><i><span style="font-family:Verdana;">e</span></i><i><span style="font-family:Verdana;">nopodium</span></i><span style="font-family:""> <i><span style="font-family:Verdana;">ambrosioides</span></i><span style="font-family:Verdana;"> in some communities in Togo reveals</span></span><span style="font-family:""> <span style="font-family:Verdana;">its importance and its medicinal properties. The plant is often infused for medicinal drinks before use. Thus, through a comparative study, this work</span><span style="font-family:Verdana;"> focused on the identification of the different phytochemical groups and then on </span><span style="font-family:Verdana;">the anti-radical capacities of ethanolic and aqueous extracts of aerial parts</span><span style="font-family:Verdana;"> (lea</span></span><span style="font-family:Verdana;">- </span><span style="font-family:""><span style="font-family:Verdana;">ves and seeds) of </span><i><span style="font-family:Verdana;">Chenopodium</span></i> <i><span style="font-family:Verdana;">ambrosiooides</span></i><span style="font-family:Verdana;"> obtained by maceration </span><span style="font-family:Verdana;">and infusion. The phytochemical tests, carried out on the various extracts, </span><span style="font-family:Verdana;">showed </span><span style="font-family:Verdana;">that they contained certain biomolecules such as flavonoids and tannins. Likewise, the presence of terpenoids and terpenes has been detected.</span><span style="font-family:Verdana;"> However, </span><span style="font-family:Verdana;">it is only in aqueous extracts that the alkaloids have been revealed. The</span><span style="font-family:Verdana;"> determination of the polyphenol content of the extracts revealed that the aqueous </span><span style="font-family:Verdana;">infusion contains 25.699 mgGAE/g DE, followed by the aqueous macera</span><span style="font-family:Verdana;">tion: 24.873 mgGAE/g DE, after the ethanolic infusion: 21.009 mg GAE/g</span><span style="font-family:Verdana;"> DE and </span><span style="font-family:Verdana;">of the ethanolic maceration: 20.625 mg GAE/g DE. The results of the</span><span style="font-family:Verdana;"> deter</span><span style="font-family:Verdana;">mination of the anti-radical capacity by the DPPH method after calculation of</span> <span><span style="font-family:Verdana;">the IC</span><sub><span style="font-family:Verdana;">50</span></sub><span style="font-family:Verdana;">, revealed that the infusion gives respectively in aqueous and etha</span></span><span style="font-family:Verdana;">nolic medium: 25.541 </span></span><span style="font-family:Verdana;">μ</span><span style="font-family:Verdana;">g/ml and 48.269 </span><span style="font-family:Verdana;">μ</span><span style="font-family:Verdana;">g/ml while the maceration leads to 29.187 </span><span style="font-family:Verdana;">μ</span><span style="font-family:Verdana;">g/ml 50.999 </span><span style="font-family:Verdana;">μ</span><span style="font-family:Verdana;">g/ml respectively. This study showed that each extract reacted with DPPH and the aqueous infusion was the most reactive.</span>展开更多
文摘The satisfaction rate of desired velocity in the case of a mixture of fast and slow vehicles is studied by using a cellular automaton method. It is found that at low density the satisfaction rate depends on the maximal velocity. However, the behavior of the satisfaction rate as a function of the coefficient of variance is independent of the maximal velocity. This is in good agreement with empirical results obtained by Lipshtat [Phys. Rev. E 79 066110 （2009）]. Furthermore, our numerical result demonstrates that at low density the satisfaction rate takes higher values, whereas the coefficient of variance is close to zero. The coefficient of variance increases with increasing density, while the satisfaction rate decreases to zero. Moreover, we have also shown that, at low density the coefficient variance depends strongly on the probability of overtaking.
文摘A better understanding of the geology and mineral potential of Africa is important in the overall context of social and economic development across the continent. Since 1995 the Association of African Women Geoscientists （AAWG） has existed, holding biennial meetings since 2002, with the aim to encourage women geoscientists to participate in Earth Sciences-related conferences, as well as to inform or become involved on gender issues related to the Earth Sciences.
基金One of the authors(J.Wandji)is grateful for grant(No.F/2624-3F)from the International Foundation for Science(Sweden)the sponsorship of the"UniversitéParis Descartes,France"during his multiple research visits in Paris.
文摘Two new compounds 7-hydroxy-5-O-（β-D-glucopyranoside） flavan （1） and （Z）-4＇,6＇-dihydroxy-2＇-O-（β-D-glucopyranoside） chalcone （2）, along with eight known compounds, were isolated from the stem bark of Drypetes parvifolia （Euphorbiaceae）. Their structures were established on the basis of spectroscopic analysis and chemical evidence.
文摘This paper introduces a novel variant of particle swarm optimization that leverages local displacements through attractors for addressing multiobjective optimization problems. The method incorporates a square root distance mechanism into the external archives to enhance the diversity. We evaluate the performance of the proposed approach on a set of constrained and unconstrained multiobjective test functions, establishing a benchmark for comparison. In order to gauge its effectiveness relative to established techniques, we conduct a comprehensive comparison with well-known approaches such as SMPSO, NSGA2 and SPEA2. The numerical results demonstrate that our method not only achieves efficiency but also exhibits competitiveness when compared to evolutionary algorithms. Particularly noteworthy is its superior performance in terms of convergence and diversification, surpassing the capabilities of its predecessors.
文摘Modeling experimental design was used to study the main effects and the interaction effects between operational parameters in the photocatalytic degradation of pesticide methomyl. The important parameters which affect the removal efficiency of methomyl such as concentration of Fe(NO3)3, concentration of H2O2, initial concentration of the pesticide and pH. The parameters were coded as x1, x2, x3 and x4, consecutively, and were investigated at two levels (–1 and +1). The effects of individual variables and their interaction effects for dependent variables, namely, photocatalytic degradation efficiency (%) were determined. From the statistical analysis, the most effective parameters in the photocatalytic degradation efficiency were initial concentrations of the methomyl and Fe(NO3)3. The interaction between initial concentration of the pesticide and Fe(NO3)3 was the most influencing interaction. The optimum conditions that were obtained for the photocatalytic degradation of methomyl were: minimum quantity of contaminant: 6 × 10–5 mol.L–1, maximum quantity of Fe(NO3)3: 5 × 10–4 mol.L-1, initial pH of the solution: 3 and maximum quantity H2O2: 10–2 mol.L–1.
文摘In this paper,we define new measures called respectively graph measure of noncompactness and graph measure of weak noncompactness.Moreover,we apply the obtained results to discuss the incidence of some perturbation results realized in [2] on the behavior of essential spectra of such closed densely defined linear operators on Banach spaces.These results are exploited to investigate the essential spectra of a multidimensional neutron transport operator on L1 spaces.
文摘Saline waters treatment has become increasingly important for drinking water supply in a greater part of the world. However, some serious limitations had recently been discovered during water treatment, among them the boron problem seems to have a critical meaning. According to the WHO regulations (2011), the boron concentration should be reduced to less than 2.4 mg/L for drinking water. The purpose of this study is to investigate the feasibility of electrocoagulation (EC) as a pretreatment process to remove boron from saline waters. To optimize the experimental conditions of boron removal, the effects of some parameters were studied such as inter-electrode distance (die), electrode connection mode, (S/V) ratio, pHi and initial conductivity of the solution (σi). Subsequently, an experimental design methodology was implemented to evaluate statistically the most significant operating parameters. The effects of current density, EC time and initial boron concentration and their mutual interaction were investigated using 23 full factorial design. At optimal conditions, boron removal from synthetic aqueous solutions containing initial boron concentrations of 5 and 50 mg/L reached 81% and 79%, respectively. Applied to boron removal from seawater samples, EC reduces boron concentration to less to 2.4 mg/L with excessive energy consumption under optimal parameters.
文摘The purpose of this study was to evaluate the acute toxicity and sedative effect of the ethylic extract of Thymelaea lythroides (Tl) on Wistar rats. The study was based on the gavage administration of the ethylic extract of Tl with different doses (i.e. 200, 400, 500 and 5000 mg/kg), where the toxicity and the sedative activity of the plant were observed and the obtained results were analyzed using the ANOVA test followed by the Bonferroni test. The main results of this study showed that the lethal dose of the ethylic extract of Tl was higher than the 5000 mg/kg dose. Moreover, when compared to the control rats, the animals treated with 5000 mg/kg of the extract exhibited significant reduction in appetite for food and water in the first week. Furthermore, results of the psychotropic test conducted during this study showed visible effects on the exploratory activity of the rats. The dose of 5000 mg/kg was also found to have a significant central nervous system effect;the locomotor activities of the animals decreased in a manner similar to those administered with Zepam as control.
文摘The objective of this project is the valorization of Mako andesitic volcanic tuffs for use in social housing in the Kedougou region. To achieve these objectives, a geotechnical characterization of the tuff samples was carried out and the geopolymerization stabilization was adopted for the manufacture of bricks. These bricks stabilized by an alkaline activation offer compressive strengths that exceed the threshold value (2.9 MPa) set by the standard (NF P14-304). The best compressive strengths (12.14 MPa) and flexural tensile strengths (5.43 MPa) are obtained in the series of bricks made with 35% of the mass of a solution of caustic soda at 12 molars concentration with a curing temperature cooking of 185°C and an average absorbance of 13.21%.
文摘An efficient and clean preparation of acylals from aromatic aldehydes in the presence of synthetic phosphates (flourapatite and hydroxyapatite doped with ZnCl2 and ZnBr2) and acetic anhydride was achieved easily in high yields (86% - 97%) at room temperature under solvent-free conditions. Deprotection of the resulting acylals has also been attained by using the same catalysts under microwave irradiation. This method consistently has advantage of excellent yields (82% - 96%) and a short reaction time (3 - 4 min).
文摘Soil salinity, which affects more than 6% of the earth’s land surface and more than 20% of its irrigated areas, is a major threat to agriculture. Diazotrophic bacteria are among the functional groups of soil microbiota that are threatened by this abiotic stress, as their activity is mostly inhibited by salt stress. Seventy bacterial strains with distinct characteristics were isolated from soils by using N-free Jensen’s selective medium. Based on their ability to produce metabolites of agricultural interest, four strains were selected and identified as Flavobacterium johnsoniae, Pseudomonas putida, Achromobacter xylosoxidans, and Azotobacter chroococcum. The selected strains were grown at different NaCl concentrations (0–600 mmol L^(-1) in N-free broth and 0–2 000 mmol L^(-1) in Luria-Bertani medium) in the presence and absence of glycine betaine (GB), aqueous and hydro-alcoholic extracts from marine macroalgae, Ulva lactuca and Enteromorpha intestinalis, and Opuntia ficus-indica cladodes. The selected bacterial strains, GB, and the aforementioned extracts were tested for their ability to promote the germination of wheat (Triticum durum) seeds at 0–300 mmol L^(-1) NaCl. Compared with the results obtained with the synthetic osmoprotectant GB, the extracts from O. ficus-indica, U. lactuca, and E. intestinalis significantly promoted bacterial growth and seed germination under salt stress.
基金funded by the Princess Nourah bint Abdulrahman University Researchers Supporting Project(PNURSP2023R29)Princess Nourah bint Abdulrahman University,Riyadh,Saudi Arabiathe Deanship of Scientific Research at King Khalid University,SaudiArabia for funding this work through Large Groups Project(L.R.G.P2/431/44)。
文摘In current report,the structural,magnetic,and thermoelectric properties of RE doped MgPm_(2)X_(4)(X=S,Se) spinels were investigated.The energy difference in ferromagnetic and antiferromagnetic states reveals the stability of MgPm_(2)(S/Se)_(4) in the ferromagnetic states.The co mputation of enthalpy of formation also ascertains thermodynamic stability of crystal structure.Spin-dependent band structure and density of states analysis reveal ferromagnetic semiconducting character showing different electronic behavior in both spin channels.The room temperature ferromagnetism,spin polarization and Curie temperature are estimated from exchange energies analysis.In addition,exchange constants(N_(0)α and N_(0)β),exchange energy Δ_(x)(pd),crystal ifeld energy,and double exchange mechanism were studied to explore the magnetic response.Likewise,the electrical conductivity,thermal conductivity,Seebeck co-efficient,and power factor show effect on electrons spin and their potential for thermoelectric devices.
文摘Several types of solid acid catalysts were prepared based on oxides like (ZrO2, TiO2, HfO2, MCM-41 and SBA-15), using two main preparation methods: the precipitation and the sol-gel methods. Each catalyst was subjected to two types of impregnations: sulfate ions using sulfuric acid as precursor and niobium using niobium oxalate as precursor. These prepared catalysts were tested in the etherification reaction of 2-naphtol, where the catalysts showed both acidic and redox properties. The acidic character was manifested through the formation of 2-butoxynaphtalene (with moderate yields) when oxide is sulfated, and the redox character (when impregnated with niobium) manifested through the formation of the interesting product 2-ethylnaphtofuran (with low yields) and other products that were a result of oxidative coupling of two 2-naphtol molecules (binol and acetal of binol). However despite the effort, several attempts to increase the yield of 2-ethylnaphtofuran did not work. All products prepared were obtained in pure form and characterized by 1H and 13C NMR, GC and MS.
文摘Several types of solid acid catalysts were prepared based on oxides like (ZrO2, TiO2, HfO2, MCM-41 and SBA-15). Each catalyst was subjected separately to two types of impregnations: sulfate ions and niobium. The catalytic activity of these solids was tested in the oxidation reaction of 1-octanol. These catalysts showed acidic and redox characters. MCM-41 and SBA-15 materials showed higher redox catalytic activities through the formation of (octyl octanoate, peroxyacetal and octanal). Our interest was focused on obtaining the ester (octyl octanoate) with high yields.
文摘The work aims to develop a process for freezing desalination of seawater on cold walls. The experiments were performed with water/NaCl solutions of different concentrations and with samples of seawater. The pilot crystallizer consists of a cooled tube immersed in a cylindrical double jacketed tank containing water to be treated. The complete process of desalination is conducted in two steps： the freezing step, leading to the crystallization of the ice layer and the sweating step, which consists of purifying the ice layer in depth by melting the impure zones. The systematic study of the influence of operating parameters has highlighted the important role of the cooling ramp and salinity of the solution on the purity of the ice produced. In the absence of stirring, the temperature of the double jacket also has a noticeable effect on the purity of the ice due to temperature gradients, and consequently, convection currents that may result in the solution. The results of this work show the feasibility of the technique and give a good indication of operating conditions that can be used to produce drinking water.
文摘Background: In most societies, homicide or murder is a crime that often leads to imprisonment. Studies around the world have sometimes found cases of mental illness (schizophrenia spectrum disorders) as an explanation for some homicides. The aim of this study was to determine the factors associated with homicide in the Togolese context. Methods: This was a descriptive and analytical cross-sectional study of pre-trial psychiatric expertise reports from January 31<sup>st</sup>, 2019 to January 30<sup>th</sup>, 2022. Results: Out of 704 defendants appraised, 206 (29.3%) had committed homicide. Males accounted for 91.7% of Homicide defendants (HD). Their average age was 31.6 ± 12.2 years, with extremes of 16 and 74 years. Factors associated with homicide were female gender, age between 30 and 45 years, married or cohabiting status and occupation as a farmer/fisherman/breeder. Psychoactive substance use (PAS), mental illness and psychiatric history were not associated with homicide. Conclusion: Preventing delinquency and interpersonal conflict, and promoting social cohesion, could significantly reduce homicides in Togo.
文摘The Design of Experiments (DOE) and the Analysis of Variance (ANOVA) are used to determine the effect of fuel type, fuel initial load, secondary air inlet and ventilation on thermal efficiency and CO emission of two biomass fire cookstoves during boiling or simmering. Analysis of variance with Fischer’s statistical test (F-test) and Newman-Keuls test were applied to establish the influence of the independent parameters on the studied responses. The results of this study are useful to application of charcoal cooks stoves.
文摘Thanks to detailed field investigations, microstructural and geochemical analysis and relationship with enclosing rocks, microfabrics, magmatic typology and metamorphic evolution of the Kantè sepentinites have been specified for the first time. The Kantè serpentinites in northern Togo constitute a mega-lens of ultrabasic rocks tectonically intercalated in the sericite chlorite schists of the Atacora structural unit. The brecciated, schitotose or massive rock facies are strongly marked by an S1 schistocity plane superimposed by a flat C shear plane linked to a west vergence thrusting movement. The parageneses that compose the metamagmatites are essentially serpentinous, containing plagioclase, opaque minerals (magnetite, chromite, spinel) and pyroxene porphyroblasts. These microfabrics represent relics of a probable gabbroic protolith. In fact, the geochemical characteristics of the Kantè serpentinites suggest that their magmatic typology is that of komatiites or tholeiitic basalts with oceanic arc affinities. They would have been emplaced in an active margin environment. The retromorphic evolution of the protolith corresponds to the phase of involvement in a major tangential contact during the panafrican tectogenesis.
文摘<span style="font-family:Verdana;">The use of </span><i><span style="font-family:Verdana;">Ch</span></i><i><span style="font-family:Verdana;">e</span></i><i><span style="font-family:Verdana;">nopodium</span></i><span style="font-family:""> <i><span style="font-family:Verdana;">ambrosioides</span></i><span style="font-family:Verdana;"> in some communities in Togo reveals</span></span><span style="font-family:""> <span style="font-family:Verdana;">its importance and its medicinal properties. The plant is often infused for medicinal drinks before use. Thus, through a comparative study, this work</span><span style="font-family:Verdana;"> focused on the identification of the different phytochemical groups and then on </span><span style="font-family:Verdana;">the anti-radical capacities of ethanolic and aqueous extracts of aerial parts</span><span style="font-family:Verdana;"> (lea</span></span><span style="font-family:Verdana;">- </span><span style="font-family:""><span style="font-family:Verdana;">ves and seeds) of </span><i><span style="font-family:Verdana;">Chenopodium</span></i> <i><span style="font-family:Verdana;">ambrosiooides</span></i><span style="font-family:Verdana;"> obtained by maceration </span><span style="font-family:Verdana;">and infusion. The phytochemical tests, carried out on the various extracts, </span><span style="font-family:Verdana;">showed </span><span style="font-family:Verdana;">that they contained certain biomolecules such as flavonoids and tannins. Likewise, the presence of terpenoids and terpenes has been detected.</span><span style="font-family:Verdana;"> However, </span><span style="font-family:Verdana;">it is only in aqueous extracts that the alkaloids have been revealed. The</span><span style="font-family:Verdana;"> determination of the polyphenol content of the extracts revealed that the aqueous </span><span style="font-family:Verdana;">infusion contains 25.699 mgGAE/g DE, followed by the aqueous macera</span><span style="font-family:Verdana;">tion: 24.873 mgGAE/g DE, after the ethanolic infusion: 21.009 mg GAE/g</span><span style="font-family:Verdana;"> DE and </span><span style="font-family:Verdana;">of the ethanolic maceration: 20.625 mg GAE/g DE. The results of the</span><span style="font-family:Verdana;"> deter</span><span style="font-family:Verdana;">mination of the anti-radical capacity by the DPPH method after calculation of</span> <span><span style="font-family:Verdana;">the IC</span><sub><span style="font-family:Verdana;">50</span></sub><span style="font-family:Verdana;">, revealed that the infusion gives respectively in aqueous and etha</span></span><span style="font-family:Verdana;">nolic medium: 25.541 </span></span><span style="font-family:Verdana;">μ</span><span style="font-family:Verdana;">g/ml and 48.269 </span><span style="font-family:Verdana;">μ</span><span style="font-family:Verdana;">g/ml while the maceration leads to 29.187 </span><span style="font-family:Verdana;">μ</span><span style="font-family:Verdana;">g/ml 50.999 </span><span style="font-family:Verdana;">μ</span><span style="font-family:Verdana;">g/ml respectively. This study showed that each extract reacted with DPPH and the aqueous infusion was the most reactive.</span>
