The present work suggested the use of waste oil palm frond as an alternative precursor for nitrogendoped carbon quantum dots(NCQDs)and proposed a straightforward in-situ hydrothermal method for the preparation of NCQD...The present work suggested the use of waste oil palm frond as an alternative precursor for nitrogendoped carbon quantum dots(NCQDs)and proposed a straightforward in-situ hydrothermal method for the preparation of NCQDs/TiO_(2)nanocomposites.The elemental composition,morphological,structural and optical characteristics of NCQDs/TiO_(2)nanocomposites have been comprehensively investigated.The successful grafting of NCQDs on TiO_(2)matrix was confirmed by the formation of Ti AOAC bond and the electronic coupling between theπ-states of NCQDs and the conduction band of TiO_(2).For the first time,the oil palm frond-derived NCQDs/TiO_(2)was adopted in the photodegradation of methylene blue(MB)under visible-light irradiation.As a result,the photocatalytic efficiency of NCQDs/TiO_(2)nanocomposites(86.16%)was 2.85 times higher than its counterpart TiO_(2)(30.18%).The enhanced performance of nanocomposites was attributed to the pivotal roles of NCQDs serving as electron mediator and visiblelight harvester.Besides,the optimal NCQDs loading was determined at 4 ml while the removal efficiency of NCQDs/TiO_(2)-4 was the highest at a catalyst dosage of 1 g.L^(-1)under alkaline condition.This research work is important as it proposed a new insight to the preparation of biomass-based NCQDs/TiO_(2)using a facile synthetic method,which offers a green and sustainable water remediation technology.展开更多
Natural fibers have become essential elements to produce composites, which have the renewability, sustainability, low cost and less health hazardous. Natural wastes improved the physical and mechanical properties of p...Natural fibers have become essential elements to produce composites, which have the renewability, sustainability, low cost and less health hazardous. Natural wastes improved the physical and mechanical properties of polyester-based composites. Reinforced polyester composites with natural fibers are spread widely in recent decades as an alternative to synthetics. This paper deals with effectiveness of palm fronds when they were added to a polyester. Percentage of palm fibers with respect to polyester is considered through present work. A Pin-on-disc tribometer has been used in experimental work under external forces, and the correlations of coefficient of friction have been used to make analysis of the experimental results. Ibertest universal testing machine was used to measure the tensile strength at a crosshead speed of 8 mm/min. The experimental analysis shows the improvement of properties of the used reinforced polyester, where, the results show that the highest values of coefficient of friction are 1.16667 for 5 N load and the lowest value is 0.55 for 9 N load. And the change for load 11 N is not significant. And also, 7.01 MPa is the highest value for tensile strength with the lowest value of modulus of rigidity 5.84 when the palm frond content is 3% and the lowest value of tensile test is 4.81 MPa with the highest value of modulus of rigidity 11.9 when 21% content.展开更多
Phenol is classified as an emerging contaminant which can be very toxic even at low concentrations and should be removed from wastewaters before reaching the environment.In this study date palm frond and leaf were pyr...Phenol is classified as an emerging contaminant which can be very toxic even at low concentrations and should be removed from wastewaters before reaching the environment.In this study date palm frond and leaf were pyrolyzed at different temperatures to identify the best adsorbent(feedstock)and pyrolysis temperature to remove phenol from aqueous solutions.Date palm frond pyrolyzed at 600℃,termed DPF600,achieved the highest phenol removal rates of 64%and adsorption capacity of 15.93 mg/g.Response surface methodology approach using Box-Behnken design was implemented to obtain the optimal pH(6),contact time(20 h)and dosage(0.1 g)for the maximum phenol adsorption.A predicted adsorption capacity was found as 16.62 mg/g which was in close agreement with the experimental adsorption capacity of 17.38 mg/g.Isotherm and kinetic models in both linear and non-linear forms indicated that Freundlich model(R^(2)=0.99,χ^(2)=0.02,RMSE=1.09)and pseudo-second order model(R^(2)=0.99,χ^(2)=0.85,RMSE=5.41)fit best the obtained experimental data.Thermodynamics calculations affirmed that the adsorption of phenol onto DPF600 biochar was endothermic and spontaneous.The point of zero charge was found to be at 6.5 for DPF600 biochar.Scanning electron microscopy coupled with energy dispersive X-ray,Fourier transform infrared spectroscopy and X-ray diffraction confirmed adsorption of phenol onto DPF600 biochar.Application of DPF600 biochar to remove phenol from synthetic primary and secondary treated wastewater samples achieved 60 and 85%removal rates and 241 mg/g and 22.28 mg/g adsorption capacities,respectively.Regeneration studies showed promising adsorption capacities indicating the efficacy of DPF600 for the removal of phenol from wastewater.展开更多
IN Permian floras of China, a dispute over the relationship among the Protoblechnum and other similar plants such as Compsopteris, Glenopteris and Supaia has been existing for a long time, and moreover it has not been...IN Permian floras of China, a dispute over the relationship among the Protoblechnum and other similar plants such as Compsopteris, Glenopteris and Supaia has been existing for a long time, and moreover it has not been completely solved up to now. Halle placed a few simple pinnate fronds from the Shihhotze Formation in the genus Protoblechnum and named them Protoblechnum Wongii Halle 70 years ago when he was studying the fossil plants from the Late Palaeozoic strata in Shanxi, China. He did not think forked or unforked fronds as an important dividing genus condition in discussing the distinction among Protoblechnum and other relative fossils. Zalessky alSO found some specimens similar to Chinese Protoblechnum while he studied the Permian fossil plants from Russia. However, he did not approve of展开更多
A well-preserved permineralized osmundaceous fern was discovered from the Middle Jurassic Tiaojishan Formation of Beipiao,Liaoning Province,China.The rhizome is about 50 cm high and 35-41 cm in diameter and can be att...A well-preserved permineralized osmundaceous fern was discovered from the Middle Jurassic Tiaojishan Formation of Beipiao,Liaoning Province,China.The rhizome is about 50 cm high and 35-41 cm in diameter and can be attributed to the genus Ashicaulis on the basis of its anatomy.The sterile pinnae are referable to Cladophlebis,the fertile pinnules are of the Todites type with in situ spores of the Osmundacidites type.Osmundaceous rhizomes have been found all over the world including the Jurassic strata of western Liaoning,China.Until now,however,no rhizomes have been reported to be organically connected with leafy organs.Although impressions and compressions of isolated osmundaceous sterile and fertile fronds are common,they were described under separate organ-or morpho-generic names,such as Todites and Cladophlebis.The new discovery provides an opportunity to study an osmundaceous fern in 'whole plant concept' to learn more about its morphology and structure,and the pa-leoclimatic and paleoenvironmental requrirements of this group.展开更多
Objective:To study the morphology,biochemistry and bioactivity of the epidermal glands of the glandular morphotype of Christella parasitica(C.parasitica)(L.) H.Lev.Methods: Morphological studies on epidermal glands we...Objective:To study the morphology,biochemistry and bioactivity of the epidermal glands of the glandular morphotype of Christella parasitica(C.parasitica)(L.) H.Lev.Methods: Morphological studies on epidermal glands were earned out by using light microscope and scanning electron microscope.To prepare the extract,the shade-dried fronds of glandular morphotype were soaked in acetone.For antibacterial studies paper disc method was followed by using various pathogenic bacteria.Results:Detailed micromorphological,phytochemical and bioactivity studies on a medicinal fern C.parasitica(L.) H.Lev.showed its inlraspecific variation in antibacterial activity.The presence or absence of the epidermal glands was the key factor for antibacterial activity in the morphovariants of this species.The epidermal glands were orange-coloured,stalked and elongated ones of about 84.2μm×45μm,and distributed on the undersurface of cosla,coslules and veins in croziers,young and mature leaves.Frequency of glands varied from 15/cm on costa in mature leaves to 140/cm on costules in croziers.The acetone extract of the glands showed antibacterial activities and also toxic effect against mosquito larvae and tadpoles of frog.Preliminary phytochemical analysis and HPLC studies of the gland extract showed the presence of various kinds of terpenoids,alkaloids,tannins,saponins and flavonoids in it.Conclusions:The present study shows that epidermal glands of the glandular morphotype of C. parasitica(L.) H.Lev.have several bioactive compounds and such rare moiphovariant should be conserved in nature.The next step is to isolate the pure compounds and to screen the bioactivity of individual compounds of the epidermal glands.展开更多
基金the funding provided by Universiti Tunku Abdul Rahman Research fund(IPSR/RMC/UTARRF/2020-C2/C06)Centre for Photonics and Advanced Materials Research(CPAMR,UTAR)for their support。
文摘The present work suggested the use of waste oil palm frond as an alternative precursor for nitrogendoped carbon quantum dots(NCQDs)and proposed a straightforward in-situ hydrothermal method for the preparation of NCQDs/TiO_(2)nanocomposites.The elemental composition,morphological,structural and optical characteristics of NCQDs/TiO_(2)nanocomposites have been comprehensively investigated.The successful grafting of NCQDs on TiO_(2)matrix was confirmed by the formation of Ti AOAC bond and the electronic coupling between theπ-states of NCQDs and the conduction band of TiO_(2).For the first time,the oil palm frond-derived NCQDs/TiO_(2)was adopted in the photodegradation of methylene blue(MB)under visible-light irradiation.As a result,the photocatalytic efficiency of NCQDs/TiO_(2)nanocomposites(86.16%)was 2.85 times higher than its counterpart TiO_(2)(30.18%).The enhanced performance of nanocomposites was attributed to the pivotal roles of NCQDs serving as electron mediator and visiblelight harvester.Besides,the optimal NCQDs loading was determined at 4 ml while the removal efficiency of NCQDs/TiO_(2)-4 was the highest at a catalyst dosage of 1 g.L^(-1)under alkaline condition.This research work is important as it proposed a new insight to the preparation of biomass-based NCQDs/TiO_(2)using a facile synthetic method,which offers a green and sustainable water remediation technology.
文摘Natural fibers have become essential elements to produce composites, which have the renewability, sustainability, low cost and less health hazardous. Natural wastes improved the physical and mechanical properties of polyester-based composites. Reinforced polyester composites with natural fibers are spread widely in recent decades as an alternative to synthetics. This paper deals with effectiveness of palm fronds when they were added to a polyester. Percentage of palm fibers with respect to polyester is considered through present work. A Pin-on-disc tribometer has been used in experimental work under external forces, and the correlations of coefficient of friction have been used to make analysis of the experimental results. Ibertest universal testing machine was used to measure the tensile strength at a crosshead speed of 8 mm/min. The experimental analysis shows the improvement of properties of the used reinforced polyester, where, the results show that the highest values of coefficient of friction are 1.16667 for 5 N load and the lowest value is 0.55 for 9 N load. And the change for load 11 N is not significant. And also, 7.01 MPa is the highest value for tensile strength with the lowest value of modulus of rigidity 5.84 when the palm frond content is 3% and the lowest value of tensile test is 4.81 MPa with the highest value of modulus of rigidity 11.9 when 21% content.
基金supported by Khalifa University (Grant number:8434000361).
文摘Phenol is classified as an emerging contaminant which can be very toxic even at low concentrations and should be removed from wastewaters before reaching the environment.In this study date palm frond and leaf were pyrolyzed at different temperatures to identify the best adsorbent(feedstock)and pyrolysis temperature to remove phenol from aqueous solutions.Date palm frond pyrolyzed at 600℃,termed DPF600,achieved the highest phenol removal rates of 64%and adsorption capacity of 15.93 mg/g.Response surface methodology approach using Box-Behnken design was implemented to obtain the optimal pH(6),contact time(20 h)and dosage(0.1 g)for the maximum phenol adsorption.A predicted adsorption capacity was found as 16.62 mg/g which was in close agreement with the experimental adsorption capacity of 17.38 mg/g.Isotherm and kinetic models in both linear and non-linear forms indicated that Freundlich model(R^(2)=0.99,χ^(2)=0.02,RMSE=1.09)and pseudo-second order model(R^(2)=0.99,χ^(2)=0.85,RMSE=5.41)fit best the obtained experimental data.Thermodynamics calculations affirmed that the adsorption of phenol onto DPF600 biochar was endothermic and spontaneous.The point of zero charge was found to be at 6.5 for DPF600 biochar.Scanning electron microscopy coupled with energy dispersive X-ray,Fourier transform infrared spectroscopy and X-ray diffraction confirmed adsorption of phenol onto DPF600 biochar.Application of DPF600 biochar to remove phenol from synthetic primary and secondary treated wastewater samples achieved 60 and 85%removal rates and 241 mg/g and 22.28 mg/g adsorption capacities,respectively.Regeneration studies showed promising adsorption capacities indicating the efficacy of DPF600 for the removal of phenol from wastewater.
文摘IN Permian floras of China, a dispute over the relationship among the Protoblechnum and other similar plants such as Compsopteris, Glenopteris and Supaia has been existing for a long time, and moreover it has not been completely solved up to now. Halle placed a few simple pinnate fronds from the Shihhotze Formation in the genus Protoblechnum and named them Protoblechnum Wongii Halle 70 years ago when he was studying the fossil plants from the Late Palaeozoic strata in Shanxi, China. He did not think forked or unforked fronds as an important dividing genus condition in discussing the distinction among Protoblechnum and other relative fossils. Zalessky alSO found some specimens similar to Chinese Protoblechnum while he studied the Permian fossil plants from Russia. However, he did not approve of
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences,(KZCX2-YW-154)the National Basic Research Program of China(2006CB701400)
文摘A well-preserved permineralized osmundaceous fern was discovered from the Middle Jurassic Tiaojishan Formation of Beipiao,Liaoning Province,China.The rhizome is about 50 cm high and 35-41 cm in diameter and can be attributed to the genus Ashicaulis on the basis of its anatomy.The sterile pinnae are referable to Cladophlebis,the fertile pinnules are of the Todites type with in situ spores of the Osmundacidites type.Osmundaceous rhizomes have been found all over the world including the Jurassic strata of western Liaoning,China.Until now,however,no rhizomes have been reported to be organically connected with leafy organs.Although impressions and compressions of isolated osmundaceous sterile and fertile fronds are common,they were described under separate organ-or morpho-generic names,such as Todites and Cladophlebis.The new discovery provides an opportunity to study an osmundaceous fern in 'whole plant concept' to learn more about its morphology and structure,and the pa-leoclimatic and paleoenvironmental requrirements of this group.
基金Supported by New Century Excellent Talents Project of the Ministry of Education (2006)Talents Introduction Fund of Tianjin University of Science and Technology (20060432 and 20080216)~~
文摘Objective:To study the morphology,biochemistry and bioactivity of the epidermal glands of the glandular morphotype of Christella parasitica(C.parasitica)(L.) H.Lev.Methods: Morphological studies on epidermal glands were earned out by using light microscope and scanning electron microscope.To prepare the extract,the shade-dried fronds of glandular morphotype were soaked in acetone.For antibacterial studies paper disc method was followed by using various pathogenic bacteria.Results:Detailed micromorphological,phytochemical and bioactivity studies on a medicinal fern C.parasitica(L.) H.Lev.showed its inlraspecific variation in antibacterial activity.The presence or absence of the epidermal glands was the key factor for antibacterial activity in the morphovariants of this species.The epidermal glands were orange-coloured,stalked and elongated ones of about 84.2μm×45μm,and distributed on the undersurface of cosla,coslules and veins in croziers,young and mature leaves.Frequency of glands varied from 15/cm on costa in mature leaves to 140/cm on costules in croziers.The acetone extract of the glands showed antibacterial activities and also toxic effect against mosquito larvae and tadpoles of frog.Preliminary phytochemical analysis and HPLC studies of the gland extract showed the presence of various kinds of terpenoids,alkaloids,tannins,saponins and flavonoids in it.Conclusions:The present study shows that epidermal glands of the glandular morphotype of C. parasitica(L.) H.Lev.have several bioactive compounds and such rare moiphovariant should be conserved in nature.The next step is to isolate the pure compounds and to screen the bioactivity of individual compounds of the epidermal glands.