The accurate assessment of soil properties is a crucial factor for composing and implementing reclamation plans. The main objective of this study was to evaluate soil chemical and physical properties and calculate the...The accurate assessment of soil properties is a crucial factor for composing and implementing reclamation plans. The main objective of this study was to evaluate soil chemical and physical properties and calculate the chemical and fertility index for assisting land reclamation in Toshka area. The Toshka area is located between latitudes 31°32'N and 31°36'N and longitudes 32°40'E and 32°60'E. GIS was used to select 16 sites. The results revealed the soil has undesirable characteristics. The soil pH ranged from slightly alkaline to moderately alkaline. Furthermore, it was characterized as saline (with a ECe of 4.65 - 11.45 dS⋅m<sup>−1</sup>) and moderately calcareous soil (with CaCO<sub>3</sub> at 11.85% - 17.20%). The soil had a low soil organic matter content which did not exceed 0.18%. The soil was dominated by a sandy loam texture (62.50%) followed by a sandy clay loam texture (18.75%). The bulk density, total soil porosity and saturated hydraulic conductivity values varied with 1.38 - 1.55 Mg⋅cm<sup>−3</sup>, 41.85% - 48.45% and 1.20 - 3.34 cm⋅h<sup>−1</sup>, respectively. The chemical index ranged from low to moderate quality. The correlations between the parameters osculated between negative and positive. Therefore, the soil may be reclaimed if the soil properties are improved and crop selection is optimized for this soil.展开更多
Plant derived natural fibers have been widely investigated as alternatives to synthetic fibers in reinforcing polymers.Researchers over the years have explored many plant fibers using different extraction processes to...Plant derived natural fibers have been widely investigated as alternatives to synthetic fibers in reinforcing polymers.Researchers over the years have explored many plant fibers using different extraction processes to study their physical,chemical,and mechanical properties.In this context,the present study relates to the extraction,characterization,and optimization of Typha angustata L.stem fibers.For this purpose,desirability functions and response surface methodology were applied to simultaneously optimize the diameter(D),linear density(LD);yield(Y),lignin fraction(L),and tenacity(T)of Typha stem fibers.Typha stems have been subjected to both alkali(NaOH)and enzymatic(pectinex ultra-SPL)treatments.Three levels of process variables including enzyme concentration(10,15,and 20 ml/L)and treatment duration(10,15,and 20 days)were used to design the experiments according to the factorial design.Experimental results were examined by analysis of variance and fitted to second order polynomial model using multiple regression analysis.The Derringer’s desirability function released that the values of process variables generating optimized diameter,linear density,yield,lignin ratio and tenacity are 20 ml/L and 20 days for concentration of pectinex ultra-SPL enzyme and treatment duration,respectively.Confirmation was performed and high degree of correlation was found between the experimental and statistical values.Moreover,the morphological structure has been investigated by the scanning electron microscope,showing a crenelated structure of ultimate fiber bundles of cellulose composing the Typha fiber.Compared to Typha stem non-treated fibers(TSNTF),Typha stem combined treated fibers(TSCTF),brings to improve mechanical properties.This change in mechanical properties is affected by modifying the fiber structure showing alpha cellulose of(66.86%)and lignin ratio of(10.83%)with a crystallinity index of(58.47%).展开更多
This study focused on the geochemical, mineralogical and technological characterization of clays in Makthar area (Central of Tunisia) of Cretaceous-Paleogene. Its aims are to identify and promote use in the field of c...This study focused on the geochemical, mineralogical and technological characterization of clays in Makthar area (Central of Tunisia) of Cretaceous-Paleogene. Its aims are to identify and promote use in the field of ceramics industry. The result of the mineralogical analysis of clays showed a dominance of illite with a percentage higher than 65%, of kaolinite and smectite with percentages of 15%. Geochemical analysis of the major elements of clay showed a SiO<sub>2</sub> content exceeding 29% and a percentage of Al<sub>2</sub>O<sub>3</sub> higher than 7.5%. The Fe<sub>2</sub>O<sub>3</sub> percentage was ranging from 3% to 8%. The percentage of CaO was between 22.5% and 28% while that of K<sub>2</sub>O is 4%. The percentages of SO<sub>4</sub>, MgO and NaO<sub>2</sub> were in very small fractions. Granulometric and microgranulometric analysis showed that the clay fraction (<2 μm) varies from 30% to 37%. The plasticity index showed the plasticity character of clays which presented a specific surface area ranging from 112 m<sup>2</sup>/g to 178 m<sup>2</sup>/g reflecting illite dominance. Drying behavior indicated that clay mixture had a drying shrinkage less than 7%, while the firing shrinkage didn’t exceed 2% giving the possibility of clay using in the ceramics field.展开更多
文摘The accurate assessment of soil properties is a crucial factor for composing and implementing reclamation plans. The main objective of this study was to evaluate soil chemical and physical properties and calculate the chemical and fertility index for assisting land reclamation in Toshka area. The Toshka area is located between latitudes 31°32'N and 31°36'N and longitudes 32°40'E and 32°60'E. GIS was used to select 16 sites. The results revealed the soil has undesirable characteristics. The soil pH ranged from slightly alkaline to moderately alkaline. Furthermore, it was characterized as saline (with a ECe of 4.65 - 11.45 dS⋅m<sup>−1</sup>) and moderately calcareous soil (with CaCO<sub>3</sub> at 11.85% - 17.20%). The soil had a low soil organic matter content which did not exceed 0.18%. The soil was dominated by a sandy loam texture (62.50%) followed by a sandy clay loam texture (18.75%). The bulk density, total soil porosity and saturated hydraulic conductivity values varied with 1.38 - 1.55 Mg⋅cm<sup>−3</sup>, 41.85% - 48.45% and 1.20 - 3.34 cm⋅h<sup>−1</sup>, respectively. The chemical index ranged from low to moderate quality. The correlations between the parameters osculated between negative and positive. Therefore, the soil may be reclaimed if the soil properties are improved and crop selection is optimized for this soil.
文摘Plant derived natural fibers have been widely investigated as alternatives to synthetic fibers in reinforcing polymers.Researchers over the years have explored many plant fibers using different extraction processes to study their physical,chemical,and mechanical properties.In this context,the present study relates to the extraction,characterization,and optimization of Typha angustata L.stem fibers.For this purpose,desirability functions and response surface methodology were applied to simultaneously optimize the diameter(D),linear density(LD);yield(Y),lignin fraction(L),and tenacity(T)of Typha stem fibers.Typha stems have been subjected to both alkali(NaOH)and enzymatic(pectinex ultra-SPL)treatments.Three levels of process variables including enzyme concentration(10,15,and 20 ml/L)and treatment duration(10,15,and 20 days)were used to design the experiments according to the factorial design.Experimental results were examined by analysis of variance and fitted to second order polynomial model using multiple regression analysis.The Derringer’s desirability function released that the values of process variables generating optimized diameter,linear density,yield,lignin ratio and tenacity are 20 ml/L and 20 days for concentration of pectinex ultra-SPL enzyme and treatment duration,respectively.Confirmation was performed and high degree of correlation was found between the experimental and statistical values.Moreover,the morphological structure has been investigated by the scanning electron microscope,showing a crenelated structure of ultimate fiber bundles of cellulose composing the Typha fiber.Compared to Typha stem non-treated fibers(TSNTF),Typha stem combined treated fibers(TSCTF),brings to improve mechanical properties.This change in mechanical properties is affected by modifying the fiber structure showing alpha cellulose of(66.86%)and lignin ratio of(10.83%)with a crystallinity index of(58.47%).
文摘This study focused on the geochemical, mineralogical and technological characterization of clays in Makthar area (Central of Tunisia) of Cretaceous-Paleogene. Its aims are to identify and promote use in the field of ceramics industry. The result of the mineralogical analysis of clays showed a dominance of illite with a percentage higher than 65%, of kaolinite and smectite with percentages of 15%. Geochemical analysis of the major elements of clay showed a SiO<sub>2</sub> content exceeding 29% and a percentage of Al<sub>2</sub>O<sub>3</sub> higher than 7.5%. The Fe<sub>2</sub>O<sub>3</sub> percentage was ranging from 3% to 8%. The percentage of CaO was between 22.5% and 28% while that of K<sub>2</sub>O is 4%. The percentages of SO<sub>4</sub>, MgO and NaO<sub>2</sub> were in very small fractions. Granulometric and microgranulometric analysis showed that the clay fraction (<2 μm) varies from 30% to 37%. The plasticity index showed the plasticity character of clays which presented a specific surface area ranging from 112 m<sup>2</sup>/g to 178 m<sup>2</sup>/g reflecting illite dominance. Drying behavior indicated that clay mixture had a drying shrinkage less than 7%, while the firing shrinkage didn’t exceed 2% giving the possibility of clay using in the ceramics field.