In this study,we attempted to characterise the effects of date-palm fibre(DPF)and a date-palm fibre/sheep wool hybrid in polyester to enhance high-performance and low-cost composite materials that can be used in insul...In this study,we attempted to characterise the effects of date-palm fibre(DPF)and a date-palm fibre/sheep wool hybrid in polyester to enhance high-performance and low-cost composite materials that can be used in insulation building systems,automotive parts,and home furniture.The DPF was treated using 5%NaOH solution;and the sheep wool was cleaned with 50℃hot water and detergents.The composite specimens were prepared with different fibre contents(0%,10%,20%,30%(w))using a compression moulding technique.The effect of fibre reinforcement was analysed in terms of the mechanical properties(tensile,flexural,impact,and hardness)and composite density.Additionally,scanning electron microscopy(SEM)was performed on the fibres before and after treatment,and the fractured surfaces of all composite specimens were examined after tensile testing.The results showed that the 20%DPF/sheep wool hybrid reinforced polyester produced the best results.The ultimate tensile strength and modulus were 27 MPa and 3.69GPa,respectively.The ultimate flexural strength and flexural modulus were 35.4 and 2507 MPa,respectively.The impact strength was 39.5 kJ/m^(2)and the hardness was 64 HB.The density decreased to the lowest value of 1.02 g/cm^(3)with the 30%DPF/sheep wool hybrid.The SEM showed good adhesion and interfacial bonding between DPF/sheep wool hybrid fibres and the polyester matrix,particularly at 20%fibre content.展开更多
Date palm(Phoenix dactylifera),one of the most ancient crops,is grown commercially in>30 countries.Using whole plastome assemblies,phylogenetic analyses revealed that cultivated date palm accessions share the same ...Date palm(Phoenix dactylifera),one of the most ancient crops,is grown commercially in>30 countries.Using whole plastome assemblies,phylogenetic analyses revealed that cultivated date palm accessions share the same clade with Phoenix sylvestris,Phoenix pusilla and Phoenix acaulis,which are native to the Indian subcontinent,and Phoenix caespitosa that is native to the Arabian Peninsula and the deserts of Somalia.Analysis of genetic diversity and genetic relationships among date palm accessions from 13 producing countries involved 195 date palm accessions that were genotyped at 19 microsatellite loci.Extensive genetic diversity was observed,with many accessions heterozygous for most markers in this clonally propagated crop.The average number of alleles per locus(42.1),expected heterozygosity(0.8),observed heterozygosity(0.47)and fixation indices(FST=0.42)demonstrated substantial genetic diversity and population structure.Iraqi accessions were found to have the richest allelic diversity,and the most private alleles.The model-based Bayesian method indicated that these accessions could be broadly divided into two structure groups,one group with predominantly African accessions and another predominantly Asian.Some germplasm,especially from Tunisia and Iraq,deviated from this generalization.Many accessions in the STRUCTURE-derived groups were found to be genetic admixtures,with gene flow between Asian and African groups.Indian and Pakistani date palms were found to be most closely related to North African germplasm.展开更多
This study presents an analysis of the impact of mycorrhizal inoculation on growth under salt stress of date palms cultivars Nakhla hamra (NHH) and Tijib known in the Sahel for their earliness in flowering and fruitin...This study presents an analysis of the impact of mycorrhizal inoculation on growth under salt stress of date palms cultivars Nakhla hamra (NHH) and Tijib known in the Sahel for their earliness in flowering and fruiting. The seedlings were grown in a greenhouse on a sandy substrate watered to field capacity every two days and were subjected to increasing levels of NaCl (0, 1, 2, 4, 6, 8 and 16 g·L-1) and then inoculated with 5 strains of Glomus (G. aggregatum, G. intraradices, G. verriculosum, G. mosseae, G. fasciculatum). The experimental design was a randomized complete block with three factors (cultivars: Tijib and Nakhla Hamra x seven levels of NaCl concentrations x six levels of inoculum). The results showed that in the absence of NaCl, G. verriculosum significantly enhanced shoot growth: 33.5 cm against 30.3 cm in the control and roots growth: 81.5 cm against 78 cm in NHH, while in Tijib, the growth is stimulated by Glomus fasciculatum: 33.8 cm against 32.7 cm for stems and 90 cm against 86 cm for the roots of inoculated plants and controls. In contrast, in the presence of NaCl 8 g·L-1, NHH has a better growth in the presence of G. intraradices: 37.3 cm against 30.6 cm for stems and 77 cm against 73 for roots, while Tijib grows better in the presence of G. fasciculatum with respectively 31.9 cm against 31.7 cm and 51.27 cm against 51.6 cm for stems and roots of inoculated plants and controls. Biochemical analysis revealed that changes in levels of proline depend on the cultivar, the mycorrhizal strain used and concentrations of NaCl applied. These results open the prospect of using mycorrhizal fungi to improve the productivity of palm trees in the Sahel.展开更多
文摘In this study,we attempted to characterise the effects of date-palm fibre(DPF)and a date-palm fibre/sheep wool hybrid in polyester to enhance high-performance and low-cost composite materials that can be used in insulation building systems,automotive parts,and home furniture.The DPF was treated using 5%NaOH solution;and the sheep wool was cleaned with 50℃hot water and detergents.The composite specimens were prepared with different fibre contents(0%,10%,20%,30%(w))using a compression moulding technique.The effect of fibre reinforcement was analysed in terms of the mechanical properties(tensile,flexural,impact,and hardness)and composite density.Additionally,scanning electron microscopy(SEM)was performed on the fibres before and after treatment,and the fractured surfaces of all composite specimens were examined after tensile testing.The results showed that the 20%DPF/sheep wool hybrid reinforced polyester produced the best results.The ultimate tensile strength and modulus were 27 MPa and 3.69GPa,respectively.The ultimate flexural strength and flexural modulus were 35.4 and 2507 MPa,respectively.The impact strength was 39.5 kJ/m^(2)and the hardness was 64 HB.The density decreased to the lowest value of 1.02 g/cm^(3)with the 30%DPF/sheep wool hybrid.The SEM showed good adhesion and interfacial bonding between DPF/sheep wool hybrid fibres and the polyester matrix,particularly at 20%fibre content.
基金funded by endowment funds from the University of Georgia Giles Professorship and the Georgia Research Alliance
文摘Date palm(Phoenix dactylifera),one of the most ancient crops,is grown commercially in>30 countries.Using whole plastome assemblies,phylogenetic analyses revealed that cultivated date palm accessions share the same clade with Phoenix sylvestris,Phoenix pusilla and Phoenix acaulis,which are native to the Indian subcontinent,and Phoenix caespitosa that is native to the Arabian Peninsula and the deserts of Somalia.Analysis of genetic diversity and genetic relationships among date palm accessions from 13 producing countries involved 195 date palm accessions that were genotyped at 19 microsatellite loci.Extensive genetic diversity was observed,with many accessions heterozygous for most markers in this clonally propagated crop.The average number of alleles per locus(42.1),expected heterozygosity(0.8),observed heterozygosity(0.47)and fixation indices(FST=0.42)demonstrated substantial genetic diversity and population structure.Iraqi accessions were found to have the richest allelic diversity,and the most private alleles.The model-based Bayesian method indicated that these accessions could be broadly divided into two structure groups,one group with predominantly African accessions and another predominantly Asian.Some germplasm,especially from Tunisia and Iraq,deviated from this generalization.Many accessions in the STRUCTURE-derived groups were found to be genetic admixtures,with gene flow between Asian and African groups.Indian and Pakistani date palms were found to be most closely related to North African germplasm.
文摘This study presents an analysis of the impact of mycorrhizal inoculation on growth under salt stress of date palms cultivars Nakhla hamra (NHH) and Tijib known in the Sahel for their earliness in flowering and fruiting. The seedlings were grown in a greenhouse on a sandy substrate watered to field capacity every two days and were subjected to increasing levels of NaCl (0, 1, 2, 4, 6, 8 and 16 g·L-1) and then inoculated with 5 strains of Glomus (G. aggregatum, G. intraradices, G. verriculosum, G. mosseae, G. fasciculatum). The experimental design was a randomized complete block with three factors (cultivars: Tijib and Nakhla Hamra x seven levels of NaCl concentrations x six levels of inoculum). The results showed that in the absence of NaCl, G. verriculosum significantly enhanced shoot growth: 33.5 cm against 30.3 cm in the control and roots growth: 81.5 cm against 78 cm in NHH, while in Tijib, the growth is stimulated by Glomus fasciculatum: 33.8 cm against 32.7 cm for stems and 90 cm against 86 cm for the roots of inoculated plants and controls. In contrast, in the presence of NaCl 8 g·L-1, NHH has a better growth in the presence of G. intraradices: 37.3 cm against 30.6 cm for stems and 77 cm against 73 for roots, while Tijib grows better in the presence of G. fasciculatum with respectively 31.9 cm against 31.7 cm and 51.27 cm against 51.6 cm for stems and roots of inoculated plants and controls. Biochemical analysis revealed that changes in levels of proline depend on the cultivar, the mycorrhizal strain used and concentrations of NaCl applied. These results open the prospect of using mycorrhizal fungi to improve the productivity of palm trees in the Sahel.
