This study examined the relationship between selected physico-mechanical properties, compacting pressure and mixing proportion of briquettes produced from combination of maize cob particles and sawdust of low, medium ...This study examined the relationship between selected physico-mechanical properties, compacting pressure and mixing proportion of briquettes produced from combination of maize cob particles and sawdust of low, medium and high density timber species. Particle sizes of maize cobs and sawdust used for the study were ≤1 mm. The two materials were combined at mixing percentages of 90:10, 70:30 and 50:50 (Sawdust:maize cobs). Briquettes were produced at room temperature (28°C) using compacting pressures 20, 30, 40 and 50 MPa. The results suggested that combining maize cob particles with sawdust of low, medium and high density wood species could significantly enhance the relaxed density, compressive strength in cleft and impact resistance index of briquettes produced from agricultural biomass residue like maize cobs. The results further indicated that the physical and mechanical characteristics of briquettes produced from combinations of sawdust of low density species and maize cobs were exceptionally higher than that produced from combinations of maize cob particles, and medium density and high density timber species. The R2 values for the regression model between the independent variables (mixing percentage and compacting pressure) and relaxed density, compressive strength in cleft and impact resistance index of briquettes produced from combinations of maize cob particles and sawdust of low density species (Ceiba pentandra) were 0.966, 0.932 and 0.710 respectively. This study provides a hope for briquetting maize cobs at room temperature using a low compacting pressure.展开更多
Corn cobs are a promising lignocellulosic substrate for the production of biofuels like bioethanol via conventional yeast or biodiesel via oleaginous yeast. Pretreatment of the substrate is essential for further hydro...Corn cobs are a promising lignocellulosic substrate for the production of biofuels like bioethanol via conventional yeast or biodiesel via oleaginous yeast. Pretreatment of the substrate is essential for further hydrolysis and fermentation steps. This study focused on the steam explosion method as pretreatment. Therefore, different steam explosion severities were evaluated. The content of glucan, xylan and Klason lignin was examined. Xylan degraded with increasing severity from 412.7 g·kg-1 （untreated） to a minimum of 127.3 g-kg1 dry matter （190 ℃/30 min）. Glucan concentrations increased from 315.1 g·kg1 （untreated） to a maximum of 371.6 g·kg-1 dry matter （200 ℃/20 min）. For soluble lignin, an increase could be observed at rising severity, from 145.3 g·kg-l （untreated） to a maximum of 214.9 g·kg-1 dry matter （190 ℃/30 min）. Furthermore, the mass recovery was calculated. At harsher pretreatment conditions, a significant mass loss was observed, estimated by the ash content in the recovered dry matter. The lowest recovery rate was observed for SF = 4.13 （190 ℃/30 min） with 68.39%. The produced inhibitors were evaluated.展开更多
Non-Starch Polysaccahride (NSP) is an agricultural byproduct containing of cellulose, hemicelluloses, and lignin. Hemicellulose has a hydroxyl functional group and carboxylic function on the monomer hemicellulose used...Non-Starch Polysaccahride (NSP) is an agricultural byproduct containing of cellulose, hemicelluloses, and lignin. Hemicellulose has a hydroxyl functional group and carboxylic function on the monomer hemicellulose used as a binding ability for cadmium ion and hence as a pharmaceutical active ingredient to prevent cadmium toxicity. The purpose of this study is to isolate and evaluate hemicelluloses from corn cobs as a binding ability toward cadmium ion. The study is conducted by isolating the corn cobs in such way using 0.2 M NaOH, characterization of hemicellulose from corn cobs produced by Infra Red Spectrofotometry. Binding ability of corn cobs hemicellulose (CCH) was done in 3 ways. The first, it was by titrimetric with cadmium 3 mg/cm3 as a titrant and indicator of 0.05 N NaOH. The second, it was by in vitro test at pH 2 as a comparison to use pectin. The third, the in vivo test was conducted in 3 variations of treatment covering CCH 10 mg, 100 mcg of cadmium for 10 weeks. Assay of cadmium was conducted using atomic absorption spectrophotometry with flame at a wavelength of 228.8 nm. The research result showed that the highest yield of hemicellulose (12.04%) was obtained from delignication with 0.03 M NaOH in 60% ethanol and 3% H2O2, hemicellulose isolation with 500 cm3 of 0.2 M NaOH, and precipitation with 1:4 ratio of 10% acetic acid in 95% ethanol. Characteristics of CCH on infrared vibration methods provide vibrational hemicellulose in the region of 1820-1600 cm-1. It meant that the functional group carbonyl was present, and the vibration widened near 3400-2400 cm-1. It indicated that there was the functional group vibration region of hydroxyl. It also meant that there was carboxylic group and finger print at 1500-500 cm-1. Test results of the titrimetric holding ability showed that CCH was binding 100 mg of cadmium (46.17 ± 0.9256) mg or 46.17%. Binding ability test results at pH 2 showed that 300 mg of CCH yield was binding 30 mg cadmium of (26.68 ± 0.1490) mg or 88.93%. The results of in vivo tests showed that cadmium levels decreased by 95.05%. Based on the exposure, it can be concluded that the CCH isolation yields of 12.04% and can reduce cadmium levels in the blood. It means that the CCH can be used as a chelating agent of cadmium ions by in vitro and in vivo.展开更多
Nowadays, the complexity of financial products makes it difficult for retail clients to identify investment risks, and there is an increasing tendency for firms, stipulated by the maximum profits, to recommend or ente...Nowadays, the complexity of financial products makes it difficult for retail clients to identify investment risks, and there is an increasing tendency for firms, stipulated by the maximum profits, to recommend or enter into unsuitable transactions to or for retail clients while providing services of investment advice and portfolio management, which causes great losses to a significant number of investors. So, in the contemporary society, the investor suitability rules through which retail clients can purchase suitable financial products are the indispensable legal basis of investor protection. Currently, the regulations concerning investor suitability management in China have several problems, including the chaotic legal system, low effectiveness level and defective contents, which may make it difficult for suitability to be applied in justice and managed effectively. Since the UK＇s investor suitability rules in the Conduct of Business Sourcebook that apply to retail clients whose contents include requirements of obtaining retail clients＇ information, requirements of information to be provided to retail clients and criteria of assessing suitability are clear and comprehensive, the authors believe that the UK＇s experiences can provide a great enlightenment for China to better investor suitability management rules, including integrating legal documents and optimizing effectiveness level, rationalizing application scope, adding criteria of assessing suitability and revising specific clauses.展开更多
The aim of this study was to evaluate the effect of ground corn cobs(GCC) as a sole fiber source in total mixed ration(TMR) on feed intake, milk yield and milk composition in tropical lactating crossbred Holstein cows...The aim of this study was to evaluate the effect of ground corn cobs(GCC) as a sole fiber source in total mixed ration(TMR) on feed intake, milk yield and milk composition in tropical lactating crossbred Holstein cows. Four multiparous crossbreds Holstein Friesian dairy cows with an initial body weight(BW) of 415.5 ± 26.20 kg were used in a 4 x 4 Latin square design. The dietary treatments of TMR contained a roughage-to-concentrate ratio of 40:60. The roughage source was used at different ratios of GCC to rice straw(RS) at 100:0, 82.5:17.5, 67.5:32.5, and 50:50 for TMR1 to TMR4, respectively. The results revealed significant improvements in intake of dry matter, protein,neutral detergent fiber(NDF)and metabolizable energy(ME) for TMR1 and TMR2(P < 0.05), while the digestibility of nutrients was not altered by the treatments(P > 0.05). Ground corn cobs was used for up to 100% of the total roughage without affecting milk production. Moreover, ruminal pH, temperature, ammonia-nitrogen(NH_3-N) and volatile fatty acid(VFA) concentrations were not impacted by the treatments(P> 0.05). However, milk yield was significantly different among the GCC:RS ratios(P < 0.05) and was the highest in TMR1 and TMR2(13.1 kg/d), while the milk compositions were not changed(P > 0.05). The results imply that using GCC as a whole roughage source significantly improved nutrients intake and milk yield in dairy cows raised in tropical areas.展开更多
Biomass-derived hard carbons,usually prepared by pyrolysis,are widely considered the most promising anode materials for sodium-ion bat-teries(SIBs)due to their high capacity,low poten-tial,sustainability,cost-effectiv...Biomass-derived hard carbons,usually prepared by pyrolysis,are widely considered the most promising anode materials for sodium-ion bat-teries(SIBs)due to their high capacity,low poten-tial,sustainability,cost-effectiveness,and environ-mental friendliness.The pyrolysis method affects the microstructure of the material,and ultimately its so-dium storage performance.Our previous work has shown that pyrolysis in a sealed graphite vessel im-proved the sodium storage performance of the car-bon,however the changes in its microstructure and the way this influences the sodium storage are still unclear.A series of hard carbon materials derived from corncobs(CCG-T,where T is the pyrolysis temperature)were pyrolyzed in a sealed graphite vessel at different temperatures.As the pyrolysis temperature increased from 1000 to 1400℃ small carbon domains gradually transformed into long and curved domains.At the same time,a greater number of large open pores with uniform apertures,as well as more closed pores,were formed.With the further increase of pyrolysis temperature to 1600℃,the long and curved domains became longer and straighter,and some closed pores gradually became open.CCG-1400,with abundant closed pores,had a superior SIB performance,with an initial reversible ca-pacity of 320.73 mAh g^(-1) at a current density of 30 mA g^(-1),an initial Coulomb efficiency(ICE)of 84.34%,and a capacity re-tention of 96.70%after 100 cycles.This study provides a method for the precise regulation of the microcrystalline and pore structures of hard carbon materials.展开更多
The aim of this research is to assess the energy potential of cow dung and corn cob inputs,with a view to estimating their biogas potential.The inputs were characterized in the microbiology laboratory of the National ...The aim of this research is to assess the energy potential of cow dung and corn cob inputs,with a view to estimating their biogas potential.The inputs were characterized in the microbiology laboratory of the National Control Office Quality in Matoto,Conakry.The experiment to produce methane from cow dung and maize cob was carried out at the Applied Research in Natural Sciences Laboratory of the University of Kindia(UK)using the following equipment:Three digesters were each connected to an air chamber(gasometer)by means of flexible pipes 8 mm in diameter,connected by clamps,liquid adhesives,valves and Teflon.This research focused on determining the quantity of biogas contained in each type of substrate(cow dung,maize cob and their mixture).Three experiments on the methanization of these inputs were carried out,with anaerobic digestion lasting 27 days,in a temperature range of 27℃ to 31℃(mesophilic range).The results were as follows:maize cob 28.4 L,cow dung 22.6 L and codigestion 38.7 L.These results compared with similar studies revealed a coincidence.展开更多
针对 LED 透镜,研究其在大功率芯片发热的影响下,改变参数所带来的不同形变和应力分布情况。以透镜材料的热膨胀系数、位置和发射率为变量,设计仿真实验进行分析。仿真结果显示,在设计大功率 LED 时,应采用热膨胀系数低的材料,为透镜涂...针对 LED 透镜,研究其在大功率芯片发热的影响下,改变参数所带来的不同形变和应力分布情况。以透镜材料的热膨胀系数、位置和发射率为变量,设计仿真实验进行分析。仿真结果显示,在设计大功率 LED 时,应采用热膨胀系数低的材料,为透镜涂覆低发射率的涂料,注意减少边角结构。展开更多
文摘This study examined the relationship between selected physico-mechanical properties, compacting pressure and mixing proportion of briquettes produced from combination of maize cob particles and sawdust of low, medium and high density timber species. Particle sizes of maize cobs and sawdust used for the study were ≤1 mm. The two materials were combined at mixing percentages of 90:10, 70:30 and 50:50 (Sawdust:maize cobs). Briquettes were produced at room temperature (28°C) using compacting pressures 20, 30, 40 and 50 MPa. The results suggested that combining maize cob particles with sawdust of low, medium and high density wood species could significantly enhance the relaxed density, compressive strength in cleft and impact resistance index of briquettes produced from agricultural biomass residue like maize cobs. The results further indicated that the physical and mechanical characteristics of briquettes produced from combinations of sawdust of low density species and maize cobs were exceptionally higher than that produced from combinations of maize cob particles, and medium density and high density timber species. The R2 values for the regression model between the independent variables (mixing percentage and compacting pressure) and relaxed density, compressive strength in cleft and impact resistance index of briquettes produced from combinations of maize cob particles and sawdust of low density species (Ceiba pentandra) were 0.966, 0.932 and 0.710 respectively. This study provides a hope for briquetting maize cobs at room temperature using a low compacting pressure.
文摘Corn cobs are a promising lignocellulosic substrate for the production of biofuels like bioethanol via conventional yeast or biodiesel via oleaginous yeast. Pretreatment of the substrate is essential for further hydrolysis and fermentation steps. This study focused on the steam explosion method as pretreatment. Therefore, different steam explosion severities were evaluated. The content of glucan, xylan and Klason lignin was examined. Xylan degraded with increasing severity from 412.7 g·kg-1 （untreated） to a minimum of 127.3 g-kg1 dry matter （190 ℃/30 min）. Glucan concentrations increased from 315.1 g·kg1 （untreated） to a maximum of 371.6 g·kg-1 dry matter （200 ℃/20 min）. For soluble lignin, an increase could be observed at rising severity, from 145.3 g·kg-l （untreated） to a maximum of 214.9 g·kg-1 dry matter （190 ℃/30 min）. Furthermore, the mass recovery was calculated. At harsher pretreatment conditions, a significant mass loss was observed, estimated by the ash content in the recovered dry matter. The lowest recovery rate was observed for SF = 4.13 （190 ℃/30 min） with 68.39%. The produced inhibitors were evaluated.
文摘Non-Starch Polysaccahride (NSP) is an agricultural byproduct containing of cellulose, hemicelluloses, and lignin. Hemicellulose has a hydroxyl functional group and carboxylic function on the monomer hemicellulose used as a binding ability for cadmium ion and hence as a pharmaceutical active ingredient to prevent cadmium toxicity. The purpose of this study is to isolate and evaluate hemicelluloses from corn cobs as a binding ability toward cadmium ion. The study is conducted by isolating the corn cobs in such way using 0.2 M NaOH, characterization of hemicellulose from corn cobs produced by Infra Red Spectrofotometry. Binding ability of corn cobs hemicellulose (CCH) was done in 3 ways. The first, it was by titrimetric with cadmium 3 mg/cm3 as a titrant and indicator of 0.05 N NaOH. The second, it was by in vitro test at pH 2 as a comparison to use pectin. The third, the in vivo test was conducted in 3 variations of treatment covering CCH 10 mg, 100 mcg of cadmium for 10 weeks. Assay of cadmium was conducted using atomic absorption spectrophotometry with flame at a wavelength of 228.8 nm. The research result showed that the highest yield of hemicellulose (12.04%) was obtained from delignication with 0.03 M NaOH in 60% ethanol and 3% H2O2, hemicellulose isolation with 500 cm3 of 0.2 M NaOH, and precipitation with 1:4 ratio of 10% acetic acid in 95% ethanol. Characteristics of CCH on infrared vibration methods provide vibrational hemicellulose in the region of 1820-1600 cm-1. It meant that the functional group carbonyl was present, and the vibration widened near 3400-2400 cm-1. It indicated that there was the functional group vibration region of hydroxyl. It also meant that there was carboxylic group and finger print at 1500-500 cm-1. Test results of the titrimetric holding ability showed that CCH was binding 100 mg of cadmium (46.17 ± 0.9256) mg or 46.17%. Binding ability test results at pH 2 showed that 300 mg of CCH yield was binding 30 mg cadmium of (26.68 ± 0.1490) mg or 88.93%. The results of in vivo tests showed that cadmium levels decreased by 95.05%. Based on the exposure, it can be concluded that the CCH isolation yields of 12.04% and can reduce cadmium levels in the blood. It means that the CCH can be used as a chelating agent of cadmium ions by in vitro and in vivo.
文摘Nowadays, the complexity of financial products makes it difficult for retail clients to identify investment risks, and there is an increasing tendency for firms, stipulated by the maximum profits, to recommend or enter into unsuitable transactions to or for retail clients while providing services of investment advice and portfolio management, which causes great losses to a significant number of investors. So, in the contemporary society, the investor suitability rules through which retail clients can purchase suitable financial products are the indispensable legal basis of investor protection. Currently, the regulations concerning investor suitability management in China have several problems, including the chaotic legal system, low effectiveness level and defective contents, which may make it difficult for suitability to be applied in justice and managed effectively. Since the UK＇s investor suitability rules in the Conduct of Business Sourcebook that apply to retail clients whose contents include requirements of obtaining retail clients＇ information, requirements of information to be provided to retail clients and criteria of assessing suitability are clear and comprehensive, the authors believe that the UK＇s experiences can provide a great enlightenment for China to better investor suitability management rules, including integrating legal documents and optimizing effectiveness level, rationalizing application scope, adding criteria of assessing suitability and revising specific clauses.
基金the Tropical Feed Resources Research and Development Center (TROFREC), Department of Animal Science, Faculty of Agriculture, Khon Kaen University(KKU), Thailand for providing financial support for the research and the use of the research facilitiessupported by the increase production efficiency and meat quality of native beef and buffalo research group, KKU
文摘The aim of this study was to evaluate the effect of ground corn cobs(GCC) as a sole fiber source in total mixed ration(TMR) on feed intake, milk yield and milk composition in tropical lactating crossbred Holstein cows. Four multiparous crossbreds Holstein Friesian dairy cows with an initial body weight(BW) of 415.5 ± 26.20 kg were used in a 4 x 4 Latin square design. The dietary treatments of TMR contained a roughage-to-concentrate ratio of 40:60. The roughage source was used at different ratios of GCC to rice straw(RS) at 100:0, 82.5:17.5, 67.5:32.5, and 50:50 for TMR1 to TMR4, respectively. The results revealed significant improvements in intake of dry matter, protein,neutral detergent fiber(NDF)and metabolizable energy(ME) for TMR1 and TMR2(P < 0.05), while the digestibility of nutrients was not altered by the treatments(P > 0.05). Ground corn cobs was used for up to 100% of the total roughage without affecting milk production. Moreover, ruminal pH, temperature, ammonia-nitrogen(NH_3-N) and volatile fatty acid(VFA) concentrations were not impacted by the treatments(P> 0.05). However, milk yield was significantly different among the GCC:RS ratios(P < 0.05) and was the highest in TMR1 and TMR2(13.1 kg/d), while the milk compositions were not changed(P > 0.05). The results imply that using GCC as a whole roughage source significantly improved nutrients intake and milk yield in dairy cows raised in tropical areas.
文摘Biomass-derived hard carbons,usually prepared by pyrolysis,are widely considered the most promising anode materials for sodium-ion bat-teries(SIBs)due to their high capacity,low poten-tial,sustainability,cost-effectiveness,and environ-mental friendliness.The pyrolysis method affects the microstructure of the material,and ultimately its so-dium storage performance.Our previous work has shown that pyrolysis in a sealed graphite vessel im-proved the sodium storage performance of the car-bon,however the changes in its microstructure and the way this influences the sodium storage are still unclear.A series of hard carbon materials derived from corncobs(CCG-T,where T is the pyrolysis temperature)were pyrolyzed in a sealed graphite vessel at different temperatures.As the pyrolysis temperature increased from 1000 to 1400℃ small carbon domains gradually transformed into long and curved domains.At the same time,a greater number of large open pores with uniform apertures,as well as more closed pores,were formed.With the further increase of pyrolysis temperature to 1600℃,the long and curved domains became longer and straighter,and some closed pores gradually became open.CCG-1400,with abundant closed pores,had a superior SIB performance,with an initial reversible ca-pacity of 320.73 mAh g^(-1) at a current density of 30 mA g^(-1),an initial Coulomb efficiency(ICE)of 84.34%,and a capacity re-tention of 96.70%after 100 cycles.This study provides a method for the precise regulation of the microcrystalline and pore structures of hard carbon materials.
文摘The aim of this research is to assess the energy potential of cow dung and corn cob inputs,with a view to estimating their biogas potential.The inputs were characterized in the microbiology laboratory of the National Control Office Quality in Matoto,Conakry.The experiment to produce methane from cow dung and maize cob was carried out at the Applied Research in Natural Sciences Laboratory of the University of Kindia(UK)using the following equipment:Three digesters were each connected to an air chamber(gasometer)by means of flexible pipes 8 mm in diameter,connected by clamps,liquid adhesives,valves and Teflon.This research focused on determining the quantity of biogas contained in each type of substrate(cow dung,maize cob and their mixture).Three experiments on the methanization of these inputs were carried out,with anaerobic digestion lasting 27 days,in a temperature range of 27℃ to 31℃(mesophilic range).The results were as follows:maize cob 28.4 L,cow dung 22.6 L and codigestion 38.7 L.These results compared with similar studies revealed a coincidence.
