The agility of production planning is defined as two characters: synchronization and flexibility. Measurement indexes for evaluating agility are then divided into two dimensions separately. Synchronization includes t...The agility of production planning is defined as two characters: synchronization and flexibility. Measurement indexes for evaluating agility are then divided into two dimensions separately. Synchronization includes two horizontal indexes: order lead time ratio and demand fulfilling rate; Two vertical indexes: instruction-reaction cycle time and resource matching rate. Flexibility includes five indexes: scope flexibility, delivery flexibility, variety flexibility, capacity buffer, inventory buffer and modification flexibility. Quantitative formulas for each measurement index are constructed. One application is discussed to illustrate the feasibility and reasonability of the indexes.展开更多
The optimized production of a novel bioflocculant M-C11 produced by Klebsiella sp. and its application in sludge dewatering were investigated. The optimal medium carbon source,nitrogen source, metal ion, initial pH an...The optimized production of a novel bioflocculant M-C11 produced by Klebsiella sp. and its application in sludge dewatering were investigated. The optimal medium carbon source,nitrogen source, metal ion, initial pH and culture temperature for the bioflocculant production were glucose, NaNO3, MgSO4, and pH 7.0 and 25°C, respectively. A compositional analysis indicated that the purified M-C11 consisted of 91.2% sugar, 4.6% protein and 3.9% nucleic acids(m/m). A Fourier transform infrared spectrum confirmed the presence of carboxyl, hydroxyl,methoxyl and amino groups. The microbial flocculant exhibited excellent pH and thermal stability in a kaolin suspension over a pH range of 4.0 to 8.0 and a temperature range of 20 to 60°C.The optimum bioflocculating activity was observed as 92.37% for 2.56 mL M-C11 and 0.37 g/L CaCl2 dosages using response surface methodology. The sludge resistance in filtration(SRF)decreased from 11.6 × 1012 to 4.7 × 1012m/kg, which indicated that the sludge dewaterability was remarkably enhanced by the bioflocculant conditioning. The sludge dewatering performance conditioned by M-C11 was more efficient than that of inorganic flocculating reagents,such as aluminum sulfate and polymeric aluminum chloride. The bioflocculant has advantages over traditional sludge conditioners due to its lower cost, benign biodegradability and negligible secondary pollution. In addition, the bioflocculant was favorably adapted to the specific sludge pH and salinity.展开更多
The effect of microwave pretreatment on the anaerobic degradation of hyacinth was investigated using response surface methodology (RSM). The components oflignin and the other constituents of hyacinth were altered by...The effect of microwave pretreatment on the anaerobic degradation of hyacinth was investigated using response surface methodology (RSM). The components oflignin and the other constituents of hyacinth were altered by microwave pretreatment. Comparison of the near-infrared spectra of hyacinth pretreated by microwave irradiation and water-heating pretreatment revealed that no new compounds were generated during hyacinth pretreatment by microwave irradiation. Atomic force microscopy observations indicated that the physical structures of hyacinth were disrupted by microwave pretreatment. The yield of methane per gram of the microwave-irradiated substrate increased by 38.3% as compared to that of the substrate pretreated via water-heating. A maximum methane yield of 221 mL·g-sub^-1 was obtained under the optimum pretreatment conditions (substrate concentration (pSC) = 20.1 g·L^-1 and pretreatment time (PT) = 14.6 min) using RSM analysis. A maximum methane production rate of 0.76 mL·h^-1· g-sub^-1 was obtained by applying PSC = 9.5 g·L^-1 and PT= 11 min. Interactive item coefficient analysis showed that methane production was dependent on the PSC and PT, separately, whereas the interactive effect of the PSC and PT on methane production was not significant. The same trend was also observed for the methane production rate.展开更多
基金This project is supported by National Natural Science Foundation of China (No.70271023).
文摘The agility of production planning is defined as two characters: synchronization and flexibility. Measurement indexes for evaluating agility are then divided into two dimensions separately. Synchronization includes two horizontal indexes: order lead time ratio and demand fulfilling rate; Two vertical indexes: instruction-reaction cycle time and resource matching rate. Flexibility includes five indexes: scope flexibility, delivery flexibility, variety flexibility, capacity buffer, inventory buffer and modification flexibility. Quantitative formulas for each measurement index are constructed. One application is discussed to illustrate the feasibility and reasonability of the indexes.
基金supported by the National Water Pollution Control Program (No. 2008ZX07313-002)
文摘The optimized production of a novel bioflocculant M-C11 produced by Klebsiella sp. and its application in sludge dewatering were investigated. The optimal medium carbon source,nitrogen source, metal ion, initial pH and culture temperature for the bioflocculant production were glucose, NaNO3, MgSO4, and pH 7.0 and 25°C, respectively. A compositional analysis indicated that the purified M-C11 consisted of 91.2% sugar, 4.6% protein and 3.9% nucleic acids(m/m). A Fourier transform infrared spectrum confirmed the presence of carboxyl, hydroxyl,methoxyl and amino groups. The microbial flocculant exhibited excellent pH and thermal stability in a kaolin suspension over a pH range of 4.0 to 8.0 and a temperature range of 20 to 60°C.The optimum bioflocculating activity was observed as 92.37% for 2.56 mL M-C11 and 0.37 g/L CaCl2 dosages using response surface methodology. The sludge resistance in filtration(SRF)decreased from 11.6 × 1012 to 4.7 × 1012m/kg, which indicated that the sludge dewaterability was remarkably enhanced by the bioflocculant conditioning. The sludge dewatering performance conditioned by M-C11 was more efficient than that of inorganic flocculating reagents,such as aluminum sulfate and polymeric aluminum chloride. The bioflocculant has advantages over traditional sludge conditioners due to its lower cost, benign biodegradability and negligible secondary pollution. In addition, the bioflocculant was favorably adapted to the specific sludge pH and salinity.
基金Acknowledgements This work was supported by the National Natural Science Foundation of China (Grant No. 51308010), the Scientific Research Project of Beijing Educational Committee (No. KM201210005028), the Research Fund for the Doctoral Program of Higher Education of China (No. 20131103120017), and the Top Youth Team of Ministry, Department of Beijing Municipal Party Committee (No. Q0004018201502).
文摘The effect of microwave pretreatment on the anaerobic degradation of hyacinth was investigated using response surface methodology (RSM). The components oflignin and the other constituents of hyacinth were altered by microwave pretreatment. Comparison of the near-infrared spectra of hyacinth pretreated by microwave irradiation and water-heating pretreatment revealed that no new compounds were generated during hyacinth pretreatment by microwave irradiation. Atomic force microscopy observations indicated that the physical structures of hyacinth were disrupted by microwave pretreatment. The yield of methane per gram of the microwave-irradiated substrate increased by 38.3% as compared to that of the substrate pretreated via water-heating. A maximum methane yield of 221 mL·g-sub^-1 was obtained under the optimum pretreatment conditions (substrate concentration (pSC) = 20.1 g·L^-1 and pretreatment time (PT) = 14.6 min) using RSM analysis. A maximum methane production rate of 0.76 mL·h^-1· g-sub^-1 was obtained by applying PSC = 9.5 g·L^-1 and PT= 11 min. Interactive item coefficient analysis showed that methane production was dependent on the PSC and PT, separately, whereas the interactive effect of the PSC and PT on methane production was not significant. The same trend was also observed for the methane production rate.