The chemical composition and thermal properties of natural fibers are the most critical variables that determine the overall properties of the fibers and influence their processing and use in different sustainable app...The chemical composition and thermal properties of natural fibers are the most critical variables that determine the overall properties of the fibers and influence their processing and use in different sustainable applications,such as their conversion into bioenergy and biocomposites.Their thermal and mechanical properties can be estimated by evaluating the content of cellulose,lignin,and other extractives in the fibers.In this research work,the chemical composition and thermal properties of three fibers,namely bagasse,kenaf bast fibers,and cotton stalks,were evaluated to assess their potential utilization in producing biocomposites and bioenergy materials.The chemical composition analysis followed the Technical Association of the Pulp and Paper Industry Standards(TAPPI)methods.The total phenol content was quantified using the Folin-Ciocalteu method,while Fourier Transform Infrared Spectroscopy(FTIR)was employed to assess the light absorption by the bonds.To evaluate thermal stability and higher heating values,Thermogravimetric Analysis(TGA),Differential Scanning Calorimetry(DSC),and bomb calorimetry were performed.The chemical analysis revealed that bagasse contained 50.6%cellulose and 21.6%lignin,kenaf bast fibers had 58.5%cellulose and 10%lignin,and cotton stalks exhibited 40.3%cellulose and 21.3%lignin.The FTIR curves demonstrated a notable similarity among the fibers.The TGA analysis showed degradation temperatures of 321°C for bagasse,354°C for kenaf bast fibers,and 289°C for cotton stalks.The DSC analysis revealed glass transition temperatures of 81°C for bagasse,66.3°C for cotton stalks,and 64.5°C for kenaf bast fibers.The higher heating values were measured as 17.3,16.6 and 17.1 MJ/kg for bagasse,kenaf bast fibers,and cotton stalks,respectively.The three fibers have a high potential for biocomposites and bioenergy material manufacturing.展开更多
The present work emphasizes the isolation of cellulose nanofiber(CNF)from the kenaf(Hibiscus cannabinus)bast through a chemo-mechanical process.In order to develop high CNF yield with superior properties of CNF for im...The present work emphasizes the isolation of cellulose nanofiber(CNF)from the kenaf(Hibiscus cannabinus)bast through a chemo-mechanical process.In order to develop high CNF yield with superior properties of CNF for improving compatibility in varied applications this method is proposed.The fiber purification involved pulping and bleaching treatments,whereas mechanical treatment was performed by grinding and high-pressure treatments.The kraft pulping as a delignification method followed by bleaching has successfully removed almost 99%lignin in the fiber with high pulp yield and delignification selectivity.The morphology of the fibers was characterized by scanning electron microscopy,which showed a smooth surface,fiber bundles,gel-shaped nanofiber,and an average size of 94.05 nm with 69%of CNF in 34–100 nm size.The chemo-mechanical process exhibited a more crystalline nature in CNF than pulp kenaf.The low zeta potential values exhibit the distribution of fibrils and colloidal suspension stability without any further agglomeration.A lower concentration of CNF is less stable exhibiting the product agglomeration.Therefore,the chemo-mechanical process for the isolation of CNF(Hibiscus cannabinus)from kenaf involves sustainable,low-cost,non-toxic,and cheap alternatives than other traditional methods.展开更多
Kenaf (Hibiscus cannabinus L) consists of various beneficial components like stalks, seeds, leaves, fibers, oils, proteins, allelopathic chemicals, and fiber strands, among other things. Despite the numerous uses of t...Kenaf (Hibiscus cannabinus L) consists of various beneficial components like stalks, seeds, leaves, fibers, oils, proteins, allelopathic chemicals, and fiber strands, among other things. Despite the numerous uses of the crop, there is little or no information on optimum agronomic practices such as planting date and N fertilization of the crop in the Upper East Region (UER) of Ghana where the crop is widely cultivated by smallholder farmers. Field experiments were therefore carried out in 2020 and repeated during the 2021 cropping season in the study area. The objective of the study was to determine appropriate planting date and N fertilization for increased kenaf productivity. In each year, the treatments consisted of 3 × 5 factorial combinations of three planting dates (1<sup>st</sup> July, 7<sup>th</sup> July and 14<sup>th</sup> July) and five levels of N (0, 20, 40, 60 and 80 kg/ha) replicated three times. The design of the experiment was a split-plot with the N fertilizer as the main plot and the planting date assigned to sub plot. The results showed that, planting kenaf in early (1<sup>st</sup>) July or N fertilization at the rate of 60 kg/ha increased plant density, stem height, stem diameter, dry bast and core yields in both cropping seasons.展开更多
The aim of this study was to simulate the solidification process of beam blank continuous casting, and then find the reasons for the typical defects of the beam blank. A two-dimensional transient coupled finite elemen...The aim of this study was to simulate the solidification process of beam blank continuous casting, and then find the reasons for the typical defects of the beam blank. A two-dimensional transient coupled finite element model has been developed to compute the temperature and stress profile in beam blank continuous casting. The enthalpy method was used in the heat conduction equation. The thermo-mechanical property in the mushy zone was taken into consideration in this calculation. It is shown that at the mold exit the thickness of the shell had its maximum value at the flange tip and its minimum value at the fillet. The temperature had a great fluctuation on the surface of the beam blank in the secondary cooling zone. At the unbending point, the surface temperature of the web was in the brittleness temperature range under the present condition. To ensure the quality, it is necessary to weaken the intensity of secondary cooling. At the mold exit the equivalent stress and strain have higher values at the flange tip and at the web. From the spray 1 to the unbending point, the maximum values of stress and strain gradually moved to the internal section of the flange tip and the web. However, whenever, there were bigger stress and strain values near the flange tip and the web than in the other parts, it must be very easy to generate cracks at those positions. Now, online verification of this simulation has been developed, which has proved to be very useful and efficient to instruct the practical production of beam blank continuous casting.展开更多
This study was conducted to investigate the effects of bast fiber seedling film on rice seedling growth. In this study, indica cultivar ＇Xiangwanxian 13＇ and indica hybrid cuitivar ＇Y Liangyou 1＇ were used to inve...This study was conducted to investigate the effects of bast fiber seedling film on rice seedling growth. In this study, indica cultivar ＇Xiangwanxian 13＇ and indica hybrid cuitivar ＇Y Liangyou 1＇ were used to investigate the changes of aboveground part growth and root respiration enzyme activities of rice seedlings af- ter the application of bast fiber seedling film. The results showed that, compared with the CK, the accumulation of shoot biomass, chlorophyll content, root bleeding intensity, soluble sugar content, and nitrate nitrogen content were significantly im- proved with the application of bast fiber seedling film. In addition, the activities of malate dehydrogenas （MDH） and alcohol dehydrogenas （ADH） were higher in rice seedling roots raised with bast fiber seedling film, while there was no significant change in lactate dehydrogenase （LDH） after the application of bast fiber seedling film. However, there were no significant differences in these indexes between the two cultivars. All the results indicated that the growth and development of rice seedlings could be improved with the application of bast fiber seedling film.展开更多
The properties and constituent of pineapple fiber were tested, and on the base of that, chemical treatment was used to improve the spinnability of the fiber, and the pure and blended yarn of pineapple fiber were produ...The properties and constituent of pineapple fiber were tested, and on the base of that, chemical treatment was used to improve the spinnability of the fiber, and the pure and blended yarn of pineapple fiber were produced in worsted and cotton spinning system.展开更多
Chinese traditional handmade papers,due to their numerous names,have been misunderstood by the public about raw materials for a long time.This manuscript aims to introduce the raw materials of traditional Chinese hand...Chinese traditional handmade papers,due to their numerous names,have been misunderstood by the public about raw materials for a long time.This manuscript aims to introduce the raw materials of traditional Chinese handmade paper in a botanical aspect in chronological order.Chinese handmade paper’s raw materials are divided into two groups,bast fiber and grass fiber.Bast fiber paper includes ramie-made rag paper,mulberry and paper mulberry paper,Thymelaeaceae paper,and vine paper.Stalk and grass fiber paper includes bamboo paper,grass paper,and stalk paper.展开更多
Cellulose whiskers were isolated from kenaf (Hibiscus cannabinus L.) bast fibers via sulfuric acid and hydrochloric acid hydrolysis. Raw kenaf bast, NaOH treated, bleached fibers, sulfuric acid whiskers (SAW) and hydr...Cellulose whiskers were isolated from kenaf (Hibiscus cannabinus L.) bast fibers via sulfuric acid and hydrochloric acid hydrolysis. Raw kenaf bast, NaOH treated, bleached fibers, sulfuric acid whiskers (SAW) and hydrochloric acid whiskers (HClW) morphology, functional groups, crystallinity, and thermal stability were characterized. The TEM images showed that the sulfuric acid and HCl whiskers have average diameters and length range of 3 nm and 100 - 500 nm, respectively. The FTIR study indicated that during the conversion process, most of the hemicellulose and almost all the lignin were removed by the NaOH and subsequent bleaching treatments. The crystallinity of HCl whiskers was found to be higher (84%) than that of sulfuric acid whiskers (72%). Thermogravimetric analysis indicated that HCl whiskers had better thermal stability than the sulfuric acid ones. In addition, a two-stage decomposition behavior was revealed by TGA in the sulfuric acid whiskers because of incorporation of the sulfate group with the cellulose crystals.展开更多
Leaves from greenhouse-grown Yucca plants were harvested and retted by microbial and chemical methods respectively.The dimensions and tensile strengths of the two sets of products were compared.While the fibers obtain...Leaves from greenhouse-grown Yucca plants were harvested and retted by microbial and chemical methods respectively.The dimensions and tensile strengths of the two sets of products were compared.While the fibers obtained by microbial retting had superior tensile strength,the chemically retted fibers were devoid of debris,whiter and generally more attractive.The method of retting should match the use to which the plant fibers are intended.展开更多
The efficacies of different products made from different parts of the stem of different varieties of kenaf grown in Nigeria as oil absorbents were tested. Particle sizes, genotypes and whether mixed or sole stem core ...The efficacies of different products made from different parts of the stem of different varieties of kenaf grown in Nigeria as oil absorbents were tested. Particle sizes, genotypes and whether mixed or sole stem core or bast differed among the treatments. The fibre component sank in water, and so was not buoyant;the core was partially buoyant while the mixed fibre and core was completely buoyant. Sorption capacity was the highest in the ground whole stem (8.16 g oil/g sorbent), which also retained (6.31 g oil/g sorbent) the highest quantity of oil. Sorption and retention of oil were the lowest in the fibre (1.66 and 0.69 g oil/g sorbent, respectively). After the first use, only the ground stem can be used to re-absorb up to 1.97 g oil/g sorbent of used sorbent. A mixture of genotypes was more absorbent than a single genotype. The implications of these findings in absorbency research are discussed.展开更多
The earliest paper currencies in existence in China were handcrafted during the Yuan dynasty.These currencies were scientifically excavated from different ruins or tombs,whereas scientific analyses of the papers are r...The earliest paper currencies in existence in China were handcrafted during the Yuan dynasty.These currencies were scientifically excavated from different ruins or tombs,whereas scientific analyses of the papers are rare.This study used optical and scanning electron microscopy to examine the fibers collected in Yuan dynasty paper currencies in conjunction with the Herzberg staining method.Despite differences in circulation period,paper fibers in both Zhi Yuan Tong Xing Bao Chao(two Guan)and Zhong Tong Yuan Bao Jiao Chao(one Guan and 500 Wen,issued in Zhi Zheng period)were identified as similar papermaking materials,bast fibers of mulberry bark.The results indicate that mulberry bark,a durable papermaking material used since ancient times,was mainly utilized as a raw material in these Yuan dynasty paper currency.This fiber identification work solved the critical problem of papermaking material in the Yuan dynasty paper currency and provided important information for conserving these precious cultural relics.展开更多
Bast fiber, which has not attracted that much attention before, is going to step up to be more recognized, so there comes the bast fiber fashion week, as an appetizer for the bast fiber promotion year.
Natural fibres are renewable,inexpensive and biodegradable sources of sustainable materials from plants or animals.Bast fibres,as the notable natural fibres,are gathered from the outer cell layers of the stem of plant...Natural fibres are renewable,inexpensive and biodegradable sources of sustainable materials from plants or animals.Bast fibres,as the notable natural fibres,are gathered from the outer cell layers of the stem of plant.Mature and young bast fibres from two species of Sesamum,namely Sesamum indicum L.and S.radiatum Schumach.&Thonn.were extracted through traditional water retting technique and analyzed for their physical,mechanical and chemical attributes.Anatomical studies revealed polygon shaped phloem(bast fibre)cells with small lumen were similar to jute,in terms of architecture,and bagasse,in terms of lumen size.Upon extraction and subsequent drying,the young stems of S.radiatum were found to yield more bast fibres by mass compared with the rest of the Sesamum samples,that was,0.59 g(dry weight)of bast fibres from 100 g(fresh weight)of stem.According to stereo microscopic images,the mature S.radiatum fibres had rougher edges than the rest.Both S.indicum and S.radiatum fibre surfaces also seemed to have pores,according to scanning electron microscopy(SEM)images.The porosity appeared to get more pronounced as the plants got older.The Sesamum bast fibres were also found to be extremely hydrophilic with a high-water retention value.The fibres obtained from S.radiatum were determined to be suitable for the textile industry due to their light colour,ideal diameter and length,and water-holding capacity that matched the requirements of fabric manufacturing.Even in the absence of a mordant,the mature fibres showed a significant degree and evenness of Alizarin dye attachment,which might be correlated to the increase in fibre surface roughness with fibre maturity.These fibres were also discovered to be comparable with jute in terms of phloem cell shape(polygonal),diameter(13-15 m),tenacity(12.86-32.54 gf/(g·km-1)),and linear density(2.5-3.3 g/km).It suggested that they might find industrial applications if further research were to be done.展开更多
A facile enantioselective synthesis of all four stereoisomers of (2E,4E)-4,6,10,12-tetramethyl-2,4-tridecadien-7-one (1) is described. The stereochemistry at 6-C and 10-C of 1 was constructed by using optically active...A facile enantioselective synthesis of all four stereoisomers of (2E,4E)-4,6,10,12-tetramethyl-2,4-tridecadien-7-one (1) is described. The stereochemistry at 6-C and 10-C of 1 was constructed by using optically active citronellal as starting material and by the asymmetric crotylic metal reaction. In the bioassay and field tests, only la, i.e. (6R,10R)-1 was active. The other three isomers 1b (6S,10R), 1c (6R,10S) and 1d (6S,10S) were inactive. Therefore, the naturally occurring pheromone was assigned as (6K,10R)-1.展开更多
Light-weight composite panels were manufactured using kenaf core particles as core material and kenaf bast fiber-woven sheets as top and bottom surfaces. Methylene diphenyldiisocyanate (MDI) resin was used as the adhe...Light-weight composite panels were manufactured using kenaf core particles as core material and kenaf bast fiber-woven sheets as top and bottom surfaces. Methylene diphenyldiisocyanate (MDI) resin was used as the adhesive with the resin content of 4% for core particles and 50 g/m2 for bast fiber- woven sheets. The target board densities were set at 0.35, 0.45 and 0.55 g/cm3. The composite panels were evaluated with Japanese Industrial Standard for Particleboards (JIS A 5908- 2003).The results show that the composite panel has high modulus of rupture and internal bonding strength. The properties of 0.45 g/cm3 density composite panel are: MOR 20.4 MPa, MOE 1.94 MPa, IB 0.36 MPa, WA142%, TS 21%. Kenaf is a good raw material for making light-weight composite panels.展开更多
基金the Tenure Track Position“Bois:Biobased materials”part of E2S UPPA supported by the“Investissements d’Avenir”French Program managed by ANR(ANR-16-IDEX-0002).
文摘The chemical composition and thermal properties of natural fibers are the most critical variables that determine the overall properties of the fibers and influence their processing and use in different sustainable applications,such as their conversion into bioenergy and biocomposites.Their thermal and mechanical properties can be estimated by evaluating the content of cellulose,lignin,and other extractives in the fibers.In this research work,the chemical composition and thermal properties of three fibers,namely bagasse,kenaf bast fibers,and cotton stalks,were evaluated to assess their potential utilization in producing biocomposites and bioenergy materials.The chemical composition analysis followed the Technical Association of the Pulp and Paper Industry Standards(TAPPI)methods.The total phenol content was quantified using the Folin-Ciocalteu method,while Fourier Transform Infrared Spectroscopy(FTIR)was employed to assess the light absorption by the bonds.To evaluate thermal stability and higher heating values,Thermogravimetric Analysis(TGA),Differential Scanning Calorimetry(DSC),and bomb calorimetry were performed.The chemical analysis revealed that bagasse contained 50.6%cellulose and 21.6%lignin,kenaf bast fibers had 58.5%cellulose and 10%lignin,and cotton stalks exhibited 40.3%cellulose and 21.3%lignin.The FTIR curves demonstrated a notable similarity among the fibers.The TGA analysis showed degradation temperatures of 321°C for bagasse,354°C for kenaf bast fibers,and 289°C for cotton stalks.The DSC analysis revealed glass transition temperatures of 81°C for bagasse,66.3°C for cotton stalks,and 64.5°C for kenaf bast fibers.The higher heating values were measured as 17.3,16.6 and 17.1 MJ/kg for bagasse,kenaf bast fibers,and cotton stalks,respectively.The three fibers have a high potential for biocomposites and bioenergy material manufacturing.
基金Ministry of Education,Culture,Research and Technology(KEMENDIKBUDRISTEK)Republic of Indonesia,for providing the Research Grant“Basic Research Scheme”No.110/E5/PG.02.00.PL/2023.
文摘The present work emphasizes the isolation of cellulose nanofiber(CNF)from the kenaf(Hibiscus cannabinus)bast through a chemo-mechanical process.In order to develop high CNF yield with superior properties of CNF for improving compatibility in varied applications this method is proposed.The fiber purification involved pulping and bleaching treatments,whereas mechanical treatment was performed by grinding and high-pressure treatments.The kraft pulping as a delignification method followed by bleaching has successfully removed almost 99%lignin in the fiber with high pulp yield and delignification selectivity.The morphology of the fibers was characterized by scanning electron microscopy,which showed a smooth surface,fiber bundles,gel-shaped nanofiber,and an average size of 94.05 nm with 69%of CNF in 34–100 nm size.The chemo-mechanical process exhibited a more crystalline nature in CNF than pulp kenaf.The low zeta potential values exhibit the distribution of fibrils and colloidal suspension stability without any further agglomeration.A lower concentration of CNF is less stable exhibiting the product agglomeration.Therefore,the chemo-mechanical process for the isolation of CNF(Hibiscus cannabinus)from kenaf involves sustainable,low-cost,non-toxic,and cheap alternatives than other traditional methods.
文摘Kenaf (Hibiscus cannabinus L) consists of various beneficial components like stalks, seeds, leaves, fibers, oils, proteins, allelopathic chemicals, and fiber strands, among other things. Despite the numerous uses of the crop, there is little or no information on optimum agronomic practices such as planting date and N fertilization of the crop in the Upper East Region (UER) of Ghana where the crop is widely cultivated by smallholder farmers. Field experiments were therefore carried out in 2020 and repeated during the 2021 cropping season in the study area. The objective of the study was to determine appropriate planting date and N fertilization for increased kenaf productivity. In each year, the treatments consisted of 3 × 5 factorial combinations of three planting dates (1<sup>st</sup> July, 7<sup>th</sup> July and 14<sup>th</sup> July) and five levels of N (0, 20, 40, 60 and 80 kg/ha) replicated three times. The design of the experiment was a split-plot with the N fertilizer as the main plot and the planting date assigned to sub plot. The results showed that, planting kenaf in early (1<sup>st</sup>) July or N fertilization at the rate of 60 kg/ha increased plant density, stem height, stem diameter, dry bast and core yields in both cropping seasons.
基金supported by the Hebei Provincial Natural Science Foundation of China(No.E2007000591).
文摘The aim of this study was to simulate the solidification process of beam blank continuous casting, and then find the reasons for the typical defects of the beam blank. A two-dimensional transient coupled finite element model has been developed to compute the temperature and stress profile in beam blank continuous casting. The enthalpy method was used in the heat conduction equation. The thermo-mechanical property in the mushy zone was taken into consideration in this calculation. It is shown that at the mold exit the thickness of the shell had its maximum value at the flange tip and its minimum value at the fillet. The temperature had a great fluctuation on the surface of the beam blank in the secondary cooling zone. At the unbending point, the surface temperature of the web was in the brittleness temperature range under the present condition. To ensure the quality, it is necessary to weaken the intensity of secondary cooling. At the mold exit the equivalent stress and strain have higher values at the flange tip and at the web. From the spray 1 to the unbending point, the maximum values of stress and strain gradually moved to the internal section of the flange tip and the web. However, whenever, there were bigger stress and strain values near the flange tip and the web than in the other parts, it must be very easy to generate cracks at those positions. Now, online verification of this simulation has been developed, which has proved to be very useful and efficient to instruct the practical production of beam blank continuous casting.
基金Supported by Scientific and Technological Innovation Project of Chinese Academy of Agricultural Sciences(ASTIP-IBFC07)Production Post of Degradable Bast Fiber Mulching Film of National Agro-Industry Technology Research System for Bast and Leaf Fiber Crops(CARS-19-E23)~~
文摘This study was conducted to investigate the effects of bast fiber seedling film on rice seedling growth. In this study, indica cultivar ＇Xiangwanxian 13＇ and indica hybrid cuitivar ＇Y Liangyou 1＇ were used to investigate the changes of aboveground part growth and root respiration enzyme activities of rice seedlings af- ter the application of bast fiber seedling film. The results showed that, compared with the CK, the accumulation of shoot biomass, chlorophyll content, root bleeding intensity, soluble sugar content, and nitrate nitrogen content were significantly im- proved with the application of bast fiber seedling film. In addition, the activities of malate dehydrogenas （MDH） and alcohol dehydrogenas （ADH） were higher in rice seedling roots raised with bast fiber seedling film, while there was no significant change in lactate dehydrogenase （LDH） after the application of bast fiber seedling film. However, there were no significant differences in these indexes between the two cultivars. All the results indicated that the growth and development of rice seedlings could be improved with the application of bast fiber seedling film.
基金This research work is financial support by the Education Ministry China.
文摘The properties and constituent of pineapple fiber were tested, and on the base of that, chemical treatment was used to improve the spinnability of the fiber, and the pure and blended yarn of pineapple fiber were produced in worsted and cotton spinning system.
文摘Chinese traditional handmade papers,due to their numerous names,have been misunderstood by the public about raw materials for a long time.This manuscript aims to introduce the raw materials of traditional Chinese handmade paper in a botanical aspect in chronological order.Chinese handmade paper’s raw materials are divided into two groups,bast fiber and grass fiber.Bast fiber paper includes ramie-made rag paper,mulberry and paper mulberry paper,Thymelaeaceae paper,and vine paper.Stalk and grass fiber paper includes bamboo paper,grass paper,and stalk paper.
文摘Cellulose whiskers were isolated from kenaf (Hibiscus cannabinus L.) bast fibers via sulfuric acid and hydrochloric acid hydrolysis. Raw kenaf bast, NaOH treated, bleached fibers, sulfuric acid whiskers (SAW) and hydrochloric acid whiskers (HClW) morphology, functional groups, crystallinity, and thermal stability were characterized. The TEM images showed that the sulfuric acid and HCl whiskers have average diameters and length range of 3 nm and 100 - 500 nm, respectively. The FTIR study indicated that during the conversion process, most of the hemicellulose and almost all the lignin were removed by the NaOH and subsequent bleaching treatments. The crystallinity of HCl whiskers was found to be higher (84%) than that of sulfuric acid whiskers (72%). Thermogravimetric analysis indicated that HCl whiskers had better thermal stability than the sulfuric acid ones. In addition, a two-stage decomposition behavior was revealed by TGA in the sulfuric acid whiskers because of incorporation of the sulfate group with the cellulose crystals.
文摘Leaves from greenhouse-grown Yucca plants were harvested and retted by microbial and chemical methods respectively.The dimensions and tensile strengths of the two sets of products were compared.While the fibers obtained by microbial retting had superior tensile strength,the chemically retted fibers were devoid of debris,whiter and generally more attractive.The method of retting should match the use to which the plant fibers are intended.
文摘The efficacies of different products made from different parts of the stem of different varieties of kenaf grown in Nigeria as oil absorbents were tested. Particle sizes, genotypes and whether mixed or sole stem core or bast differed among the treatments. The fibre component sank in water, and so was not buoyant;the core was partially buoyant while the mixed fibre and core was completely buoyant. Sorption capacity was the highest in the ground whole stem (8.16 g oil/g sorbent), which also retained (6.31 g oil/g sorbent) the highest quantity of oil. Sorption and retention of oil were the lowest in the fibre (1.66 and 0.69 g oil/g sorbent, respectively). After the first use, only the ground stem can be used to re-absorb up to 1.97 g oil/g sorbent of used sorbent. A mixture of genotypes was more absorbent than a single genotype. The implications of these findings in absorbency research are discussed.
文摘The earliest paper currencies in existence in China were handcrafted during the Yuan dynasty.These currencies were scientifically excavated from different ruins or tombs,whereas scientific analyses of the papers are rare.This study used optical and scanning electron microscopy to examine the fibers collected in Yuan dynasty paper currencies in conjunction with the Herzberg staining method.Despite differences in circulation period,paper fibers in both Zhi Yuan Tong Xing Bao Chao(two Guan)and Zhong Tong Yuan Bao Jiao Chao(one Guan and 500 Wen,issued in Zhi Zheng period)were identified as similar papermaking materials,bast fibers of mulberry bark.The results indicate that mulberry bark,a durable papermaking material used since ancient times,was mainly utilized as a raw material in these Yuan dynasty paper currency.This fiber identification work solved the critical problem of papermaking material in the Yuan dynasty paper currency and provided important information for conserving these precious cultural relics.
文摘Bast fiber, which has not attracted that much attention before, is going to step up to be more recognized, so there comes the bast fiber fashion week, as an appetizer for the bast fiber promotion year.
文摘Natural fibres are renewable,inexpensive and biodegradable sources of sustainable materials from plants or animals.Bast fibres,as the notable natural fibres,are gathered from the outer cell layers of the stem of plant.Mature and young bast fibres from two species of Sesamum,namely Sesamum indicum L.and S.radiatum Schumach.&Thonn.were extracted through traditional water retting technique and analyzed for their physical,mechanical and chemical attributes.Anatomical studies revealed polygon shaped phloem(bast fibre)cells with small lumen were similar to jute,in terms of architecture,and bagasse,in terms of lumen size.Upon extraction and subsequent drying,the young stems of S.radiatum were found to yield more bast fibres by mass compared with the rest of the Sesamum samples,that was,0.59 g(dry weight)of bast fibres from 100 g(fresh weight)of stem.According to stereo microscopic images,the mature S.radiatum fibres had rougher edges than the rest.Both S.indicum and S.radiatum fibre surfaces also seemed to have pores,according to scanning electron microscopy(SEM)images.The porosity appeared to get more pronounced as the plants got older.The Sesamum bast fibres were also found to be extremely hydrophilic with a high-water retention value.The fibres obtained from S.radiatum were determined to be suitable for the textile industry due to their light colour,ideal diameter and length,and water-holding capacity that matched the requirements of fabric manufacturing.Even in the absence of a mordant,the mature fibres showed a significant degree and evenness of Alizarin dye attachment,which might be correlated to the increase in fibre surface roughness with fibre maturity.These fibres were also discovered to be comparable with jute in terms of phloem cell shape(polygonal),diameter(13-15 m),tenacity(12.86-32.54 gf/(g·km-1)),and linear density(2.5-3.3 g/km).It suggested that they might find industrial applications if further research were to be done.
基金supported by the National Natural Science Foundation of China.
文摘A facile enantioselective synthesis of all four stereoisomers of (2E,4E)-4,6,10,12-tetramethyl-2,4-tridecadien-7-one (1) is described. The stereochemistry at 6-C and 10-C of 1 was constructed by using optically active citronellal as starting material and by the asymmetric crotylic metal reaction. In the bioassay and field tests, only la, i.e. (6R,10R)-1 was active. The other three isomers 1b (6S,10R), 1c (6R,10S) and 1d (6S,10S) were inactive. Therefore, the naturally occurring pheromone was assigned as (6K,10R)-1.
基金Supported by the talent fund of the Central South University of Forestry and Technology.
文摘Light-weight composite panels were manufactured using kenaf core particles as core material and kenaf bast fiber-woven sheets as top and bottom surfaces. Methylene diphenyldiisocyanate (MDI) resin was used as the adhesive with the resin content of 4% for core particles and 50 g/m2 for bast fiber- woven sheets. The target board densities were set at 0.35, 0.45 and 0.55 g/cm3. The composite panels were evaluated with Japanese Industrial Standard for Particleboards (JIS A 5908- 2003).The results show that the composite panel has high modulus of rupture and internal bonding strength. The properties of 0.45 g/cm3 density composite panel are: MOR 20.4 MPa, MOE 1.94 MPa, IB 0.36 MPa, WA142%, TS 21%. Kenaf is a good raw material for making light-weight composite panels.
