The objective of this work is to develop new biosourced insulating composites from rice husks and wood chips that can be used in the building sector. It appears from the properties of the precursors that rice chips an...The objective of this work is to develop new biosourced insulating composites from rice husks and wood chips that can be used in the building sector. It appears from the properties of the precursors that rice chips and husks are materials which can have good thermal conductivity and therefore the combination of these precursors could make it possible to obtain panels with good insulating properties. With regard to environmental and climatic constraints, the composite panels formulated at various rates were tested and the physico-mechanical and thermal properties showed that it was essential to add a crosslinker in order to increase certain solicitation. an incorporation rate of 12% to 30% made it possible to obtain panels with low thermal conductivity, a low surface water absorption capacity and which gives the composite good thermal insulation and will find many applications in the construction and real estate sector. Finally, new solutions to improve the fire reaction of the insulation panels are tested which allows to identify suitable solutions for the developed composites. In view of the flame tests, the panels obtained are good and can effectively combat fire safety in public buildings.展开更多
The use of steel reinforced concrete facade is gradually becoming unpopular because of the damage caused to the elements as a result of corrosion of the steel reinforcement. It is now possible to build lightweight and...The use of steel reinforced concrete facade is gradually becoming unpopular because of the damage caused to the elements as a result of corrosion of the steel reinforcement. It is now possible to build lightweight and slender concrete structures which are invulnerable to corrosion with the use of fiber reinforcements, which are gradually replacing the corrosion prone steel. This paper describes the construction of faqade panels made of rattan cane reinforcements and steel reinforcements, ten number model sized elements of area 0.15 m2 and a depth of 40 mm were considered, with five panels for each reinforcement type. The elements were subjected to incremental load of 1 kN until failure occurred. Deflections were measured for each element, and crack width was measured at failure load. The results for both types of reinforcements when compared showed the rattan cane reinforced panels failing earlier than the steel reinforced panels. However a lower defection and crack width was recorded in the rattan cane reinforced panel. This paper concludes that the lower crack width formed after failure in the rattan cane reinforced panel gave it advantage over the steel reinforced panel, since it has lower space for the ingress of water which is the main agents of corrosion.展开更多
The efficiency and selectivity of chlorimuron-ethyl （107 g/kg） associated with metribuzin （643 g/kg）, against weeds which causes big damages to sugar cane, have been studied on the sugar cane field of Beregadougou...The efficiency and selectivity of chlorimuron-ethyl （107 g/kg） associated with metribuzin （643 g/kg）, against weeds which causes big damages to sugar cane, have been studied on the sugar cane field of Beregadougou. The experimental design was a Latin rectangle with eight treatments in four replications including an untreated control, manual weeding, a control product （Trifloxysulfuron-sdium 1.85% ＋ Ametryn 73.15%） and five rates of chlorimuron-ethyl associated with metribuzin. Weeds counting and weighing their dry biomass have been done using 0.25 m2 quadrants to determine their biological efficiencies. The soil nitrogen nitrate and assimilable phosphorus contents were evaluated on a spectrophotometer, those of available potassium on a flame photometer. The biological efficiency coefficients of this herbicide, varied from 12.41% to 100%, according to their dry biomass. High rates, phytotoxics, showed the best coefficients. At the sugar cane complete maturation, the higher rates of imposter led to an accumulation of nitrogen nitrate content and lower available phosphorus and potassium contents, compared to the untreated control. The rate of 1.20 kg/ha became the dose to apply against weeds and less toxic to the soil.展开更多
To obtain the mechanical properties of greenhouse cucumber cane,tensile and shear properties of the greenhouse cucumber cane were studied by using computer-controlled electronic universal testing machine and homemade ...To obtain the mechanical properties of greenhouse cucumber cane,tensile and shear properties of the greenhouse cucumber cane were studied by using computer-controlled electronic universal testing machine and homemade cutting test bench,respectively.Firstly,the root,middle and head of cucumber cane were subjected for tensile tests.The tensile stress-strain curves showed that the root of cumber cane presented the characteristics of plastic material,while the middle and head showed the characteristics of brittle material.The average tensile strength of root,middle and head of fresh cucumber cane were 7.35 MPa,6.30 MPa and 4.68 MPa,respectively.The average elastic modulus of root of fresh cucumber cane was 280.58 MPa,which was much greater than the middle and head with average elastic modulus of 198.81 MPa and 137.22 MPa,respectively.A pendulum impact cutting test-rig and a cutting force measurement system composed of a cantilever weigh sensor,a high frequency DAQ card and motion control card were developed.The cutting mechanical property experiments of different parts of greenhouse cucumber cane were carried out,and the continuous curves of cutting force were measured.The single factor test for cross-sectional area,cutting speed,cutting tool type and manner were analyzed.The results indicated that the peak cutting force increased approximately linearly with the increasing of cutting sectional area,but decreased gradually with the increasing of cutting speed.In the same conditions,the cutting force could be reduced by using straight blade cutting tool and ramp cutting way.Through the multifactor interaction impact test of the cutting way,the blade type and the cutting speed,it was found that the corresponding F-value of the three factors were 21.316,49.141 and 0.222,which suggests that the blade type is the most significant factor for the cutting force.展开更多
We investigated the resistance of acetylated rattan against soft rot and other soil inhabiting micro-organisms in comparison with wood of beech and Scots pine. Calamus manan of 10 and 13 years old under rubber tree ca...We investigated the resistance of acetylated rattan against soft rot and other soil inhabiting micro-organisms in comparison with wood of beech and Scots pine. Calamus manan of 10 and 13 years old under rubber tree canopy was acetylated to different levels by reaction times （0.25 to 30 hours） and was tested for soft rot decay for 32 weeks. Acetylated rattan at decay protection thresholds of 15.4% and 16.2% weight gain （WG） were fully protected, as shown by both weight loss and strength loss criteria. The static bending properties of untreated rattan decayed by soft rot were significantly lower than for acetylated rattan.展开更多
[Objectives]To explore the proper intercropping pattern between chewing cane and peanut.[Methods]A field experiment was carried out to investigate the yield and economic benefit of chewing cane and peanut,as well as t...[Objectives]To explore the proper intercropping pattern between chewing cane and peanut.[Methods]A field experiment was carried out to investigate the yield and economic benefit of chewing cane and peanut,as well as the changes in soil properties under different chewing cane/peanut intercropping patterns.Three chewing cane/peanut intercropping patterns were designed,in which with every row of chewing cane intercropping one row of peanut(CP_(1)),intercropping two rows of peanut(CP_(2))and chewing cane mono-cropping(MC).[Results]It had no significant effect on the agronomic characters of chewing cane and peanut in CP_(1)and CP_(2),compared with MC.The soil properties before the planting(BP)and after the harvest(AH)indicated that the chewing cane/peanut intercropping patterns significantly increased soil organic matter and soil available nitrogen contents,but decreased soil available potassium contents,and CP_(2)had better effect on soil structure than CP_(1).The total production value and economic benefit were increased significantly on the CP_(1)and CP_(2),comparing the MC,and the benefit of CP_(2)was higher significantly than that of CP_(1).The land equivalent ratios(LER)for CP_(1)and CP_(2)were 1.94 and 1.72,respectively,which was significantly higher than that of MC(0.83).Although planting cost was increased in chewing cane/peanut intercropping patterns partly,the production value and the profits were enhanced significantly.[Conclusions]CP_(2)could be significantly advantageous for the yield and benefits of chewing cane and peanut and soil properties.The favorable intercropping pattern for economic return would be one row of 120 cm width for chewing cane with two rows of peanut.展开更多
Study on the basic anatomical characteristics of rattan canes will give great guidance to their classification, exploitation, utilization, processing and improvement. The basic anatomical characteristics and their var...Study on the basic anatomical characteristics of rattan canes will give great guidance to their classification, exploitation, utilization, processing and improvement. The basic anatomical characteristics and their variation in cane of three commercial rattans in South China, i.e. Calamus simplicifolius, Calamus tetradactylus and Daemonorops margaritae were investigated. Results show that: 1) The variation at the height of rattan canes is small, while the variation along the radius direction of rattan canes is significant. 2) The fiber length, fiber ratio and distributing density of vascular bundle in the cross section decrease from cortex to core, while the fiber width, vessel element length and width, parenchyma ratio, vessel ratio, vascular bundle size, metaxylem vessel diameter and fiber microfibrillar angle in the cross section increase from cortex to core. The cellulose crystallinity of stem core is bigger than that of the cortex. 3) All these three rattan possess the cane structure characteristics of good commercial rattan cane. As for the anatomical structure, C. simplicifolius is the best and C. tetradactylus is better than D. margaritae. 4) According to the anatomic study, the penetration approach of rattan cane is mainly the longitudinal axial passage around the core; it is an important research direction to improve the penetrability of rattan cane.展开更多
文摘The objective of this work is to develop new biosourced insulating composites from rice husks and wood chips that can be used in the building sector. It appears from the properties of the precursors that rice chips and husks are materials which can have good thermal conductivity and therefore the combination of these precursors could make it possible to obtain panels with good insulating properties. With regard to environmental and climatic constraints, the composite panels formulated at various rates were tested and the physico-mechanical and thermal properties showed that it was essential to add a crosslinker in order to increase certain solicitation. an incorporation rate of 12% to 30% made it possible to obtain panels with low thermal conductivity, a low surface water absorption capacity and which gives the composite good thermal insulation and will find many applications in the construction and real estate sector. Finally, new solutions to improve the fire reaction of the insulation panels are tested which allows to identify suitable solutions for the developed composites. In view of the flame tests, the panels obtained are good and can effectively combat fire safety in public buildings.
文摘The use of steel reinforced concrete facade is gradually becoming unpopular because of the damage caused to the elements as a result of corrosion of the steel reinforcement. It is now possible to build lightweight and slender concrete structures which are invulnerable to corrosion with the use of fiber reinforcements, which are gradually replacing the corrosion prone steel. This paper describes the construction of faqade panels made of rattan cane reinforcements and steel reinforcements, ten number model sized elements of area 0.15 m2 and a depth of 40 mm were considered, with five panels for each reinforcement type. The elements were subjected to incremental load of 1 kN until failure occurred. Deflections were measured for each element, and crack width was measured at failure load. The results for both types of reinforcements when compared showed the rattan cane reinforced panels failing earlier than the steel reinforced panels. However a lower defection and crack width was recorded in the rattan cane reinforced panel. This paper concludes that the lower crack width formed after failure in the rattan cane reinforced panel gave it advantage over the steel reinforced panel, since it has lower space for the ingress of water which is the main agents of corrosion.
文摘The efficiency and selectivity of chlorimuron-ethyl （107 g/kg） associated with metribuzin （643 g/kg）, against weeds which causes big damages to sugar cane, have been studied on the sugar cane field of Beregadougou. The experimental design was a Latin rectangle with eight treatments in four replications including an untreated control, manual weeding, a control product （Trifloxysulfuron-sdium 1.85% ＋ Ametryn 73.15%） and five rates of chlorimuron-ethyl associated with metribuzin. Weeds counting and weighing their dry biomass have been done using 0.25 m2 quadrants to determine their biological efficiencies. The soil nitrogen nitrate and assimilable phosphorus contents were evaluated on a spectrophotometer, those of available potassium on a flame photometer. The biological efficiency coefficients of this herbicide, varied from 12.41% to 100%, according to their dry biomass. High rates, phytotoxics, showed the best coefficients. At the sugar cane complete maturation, the higher rates of imposter led to an accumulation of nitrogen nitrate content and lower available phosphorus and potassium contents, compared to the untreated control. The rate of 1.20 kg/ha became the dose to apply against weeds and less toxic to the soil.
基金the National Key Technologies R&D Program of China(No.2014BAD08B04)the National Natural Science Fund of China(No.51175230,No.51475212)+1 种基金Independent Innovation of Agricultural Science and Technology Project in Jiangsu Province(cx(10)224)Research and Innovation Project for College Graduates of Jiangsu Province of China(CXLX12_0625).
文摘To obtain the mechanical properties of greenhouse cucumber cane,tensile and shear properties of the greenhouse cucumber cane were studied by using computer-controlled electronic universal testing machine and homemade cutting test bench,respectively.Firstly,the root,middle and head of cucumber cane were subjected for tensile tests.The tensile stress-strain curves showed that the root of cumber cane presented the characteristics of plastic material,while the middle and head showed the characteristics of brittle material.The average tensile strength of root,middle and head of fresh cucumber cane were 7.35 MPa,6.30 MPa and 4.68 MPa,respectively.The average elastic modulus of root of fresh cucumber cane was 280.58 MPa,which was much greater than the middle and head with average elastic modulus of 198.81 MPa and 137.22 MPa,respectively.A pendulum impact cutting test-rig and a cutting force measurement system composed of a cantilever weigh sensor,a high frequency DAQ card and motion control card were developed.The cutting mechanical property experiments of different parts of greenhouse cucumber cane were carried out,and the continuous curves of cutting force were measured.The single factor test for cross-sectional area,cutting speed,cutting tool type and manner were analyzed.The results indicated that the peak cutting force increased approximately linearly with the increasing of cutting sectional area,but decreased gradually with the increasing of cutting speed.In the same conditions,the cutting force could be reduced by using straight blade cutting tool and ramp cutting way.Through the multifactor interaction impact test of the cutting way,the blade type and the cutting speed,it was found that the corresponding F-value of the three factors were 21.316,49.141 and 0.222,which suggests that the blade type is the most significant factor for the cutting force.
文摘We investigated the resistance of acetylated rattan against soft rot and other soil inhabiting micro-organisms in comparison with wood of beech and Scots pine. Calamus manan of 10 and 13 years old under rubber tree canopy was acetylated to different levels by reaction times （0.25 to 30 hours） and was tested for soft rot decay for 32 weeks. Acetylated rattan at decay protection thresholds of 15.4% and 16.2% weight gain （WG） were fully protected, as shown by both weight loss and strength loss criteria. The static bending properties of untreated rattan decayed by soft rot were significantly lower than for acetylated rattan.
基金Supported by Natural Science Foundation of Guangxi(2021GXNSFAA-075039)Scientific Base and Talents Foundation of Guangxi(AD20297103).
文摘[Objectives]To explore the proper intercropping pattern between chewing cane and peanut.[Methods]A field experiment was carried out to investigate the yield and economic benefit of chewing cane and peanut,as well as the changes in soil properties under different chewing cane/peanut intercropping patterns.Three chewing cane/peanut intercropping patterns were designed,in which with every row of chewing cane intercropping one row of peanut(CP_(1)),intercropping two rows of peanut(CP_(2))and chewing cane mono-cropping(MC).[Results]It had no significant effect on the agronomic characters of chewing cane and peanut in CP_(1)and CP_(2),compared with MC.The soil properties before the planting(BP)and after the harvest(AH)indicated that the chewing cane/peanut intercropping patterns significantly increased soil organic matter and soil available nitrogen contents,but decreased soil available potassium contents,and CP_(2)had better effect on soil structure than CP_(1).The total production value and economic benefit were increased significantly on the CP_(1)and CP_(2),comparing the MC,and the benefit of CP_(2)was higher significantly than that of CP_(1).The land equivalent ratios(LER)for CP_(1)and CP_(2)were 1.94 and 1.72,respectively,which was significantly higher than that of MC(0.83).Although planting cost was increased in chewing cane/peanut intercropping patterns partly,the production value and the profits were enhanced significantly.[Conclusions]CP_(2)could be significantly advantageous for the yield and benefits of chewing cane and peanut and soil properties.The favorable intercropping pattern for economic return would be one row of 120 cm width for chewing cane with two rows of peanut.
文摘Study on the basic anatomical characteristics of rattan canes will give great guidance to their classification, exploitation, utilization, processing and improvement. The basic anatomical characteristics and their variation in cane of three commercial rattans in South China, i.e. Calamus simplicifolius, Calamus tetradactylus and Daemonorops margaritae were investigated. Results show that: 1) The variation at the height of rattan canes is small, while the variation along the radius direction of rattan canes is significant. 2) The fiber length, fiber ratio and distributing density of vascular bundle in the cross section decrease from cortex to core, while the fiber width, vessel element length and width, parenchyma ratio, vessel ratio, vascular bundle size, metaxylem vessel diameter and fiber microfibrillar angle in the cross section increase from cortex to core. The cellulose crystallinity of stem core is bigger than that of the cortex. 3) All these three rattan possess the cane structure characteristics of good commercial rattan cane. As for the anatomical structure, C. simplicifolius is the best and C. tetradactylus is better than D. margaritae. 4) According to the anatomic study, the penetration approach of rattan cane is mainly the longitudinal axial passage around the core; it is an important research direction to improve the penetrability of rattan cane.
