A novel method based on the selective pressure of particle size (particle-size cultivation method, PSCM) was developed for the cultivation and operation of aerobic granular sludge in a continuous-flow reactor, and c...A novel method based on the selective pressure of particle size (particle-size cultivation method, PSCM) was developed for the cultivation and operation of aerobic granular sludge in a continuous-flow reactor, and compared with the conventional method based on the selective pressure of settling velocity (settling-velocity cultivation method, SVCM). Results indicated that aerobic granules could be cultivated in continuous operation mode by this developed method within 14 days. Although in the granulation process, under particle-size selective pressure, mixed liquor suspended solids (MLSS) in the reactor fluctuated greatly and filamentous bacteria dominated the sludge system during the initial operation days, no obvious difference in profile was found between the aerobic granules cultivated by PSCM and SVCM. Moreover, aerobic granules cultivated by PSCM presented larger diameter, lower water content and higher specific rates of nitrification, denitrifieation and phosphorus removal, but lower settling velocity. Under long term operation of more than 30 days, aerobic granules in the continuous-flow reactor could remain stable and obtain good chemical oxygen demand (COD), NH4^+-N, total nitrogen (TN) and total phosphorus (TP) removal. The results indicate that PSCM was dependent on the cultivation and maintenance of the stability of aerobic granules in continuous-flow bioreactors.展开更多
Contamination between batches in multi-products pipeline transport is studied. The influences of convection and diffusion on the contamination are studied in detail. Diffusion equations, which are mainly controlled by...Contamination between batches in multi-products pipeline transport is studied. The influences of convection and diffusion on the contamination are studied in detail. Diffusion equations, which are mainly controlled by convection, are developed under turbulent pipe flow. The diffusion equation is separated into a pure convection equation and a pure diffusion equation which are solved by characteristics method and finite difference method respectively to obtain numerical solutions. The results of numerical computation explain the forming and developing of contamination very well.展开更多
<div style="text-align:justify;"> <span style="font-family:Verdana;">The aim of this work was to use fish processing waste (FW) as main substrate for anaerobic digestion. To enhance the...<div style="text-align:justify;"> <span style="font-family:Verdana;">The aim of this work was to use fish processing waste (FW) as main substrate for anaerobic digestion. To enhance the biogas production of FW, co-digestion was done with two other substrates: cow dung (CD) and waste of market (MW). Batch test was carried out in an 1</span><span "=""><span style="font-family:Verdana;"> L glass digester in a temperature controlled chamber at 38</span><span style="color:#4F4F4F;font-family:Verdana;">°</span><span style="font-family:Verdana;">C. The following mixtures were carried out: FW with CD respectively at different ratios 100:0% (A), 80:20%</span></span><span "=""> </span><span "="" style="font-family:Verdana;">(B) and 60:40% (C);FW with MW at the following ratio 80:20% (D);FW with CD and MW respectively at these ratios 80:10:10% (F) and 60:20:20% (G). The biogas produced was measured using a milligas counter</span><sup><span style="color:#4F4F4F;"><span style="color:#4F4F4F;font-family:Verdana;">®</span><span style="font-family:Verdana;"></span></span></sup><span "="" style="font-family:Verdana;"> and the volume of gas was recorded. The gas composition was determined using gas chromatography. With a pH stable for raw substrates and mixtures, TS and VS (%TS) contents for FW were respectively 31.01% and 91.55%. Between 3 to 13 days of experimentation, the highest flow rate was observed. The percentage of methane was more important for mixtures B and D, 61% and 59% respectively. pH and VOA/T</span><span "="" style="font-family:Verdana;">IC were stable at the end of the batch test for all mixtures, meaning that the organic matter was already well digested. The highest values of Volatile Solid Removal (VSR) were found for mixtures C, D, F and G. Therefore, the promising mixtures for next experimentations in large scale are B and D.</span> </div>展开更多
In this paper,a case study is carried out in comparison of pipes-and-filters architecture and batch sequential architecture.Concepts on a data flow system and the two mentioned architectures are presented.A Java templ...In this paper,a case study is carried out in comparison of pipes-and-filters architecture and batch sequential architecture.Concepts on a data flow system and the two mentioned architectures are presented.A Java template class design in implementing the "pipes" and "filters" in the pipes-and-filters architecture is given at the design level.Finally,this paper uses a concrete example to show how to use Java to implement the pipesand-filters architecture.Using varied amount of data from text files,performance and memory usage of the two architectures are illustrated.展开更多
充分考虑实际生产过程中的批量生产形式,构建以最小最大完工时间为目标的置换流水车间分批调度问题的数学模型,并提出一种改进的人工兔优化算法。在编码阶段,采用最小位置值(smallest position value,SPV)规则实现连续解向离散解的转变...充分考虑实际生产过程中的批量生产形式,构建以最小最大完工时间为目标的置换流水车间分批调度问题的数学模型,并提出一种改进的人工兔优化算法。在编码阶段,采用最小位置值(smallest position value,SPV)规则实现连续解向离散解的转变;在解码阶段,采用动态策略对工件进行分批;通过NEH启发式规则改善初始种群的质量;引入差分进化算子提高解的多样性;提出基于交换和逆序的局部搜索策略增强算法跳出局部最优解的能力。将所提算法和其他对比算法对不同规模的算例进行求解,通过消融实验、对比实验、统计检验等证明了算法的有效性。最后对某汽车外饰件厂喷涂车间排产问题进行求解,求解结果优于其他对比算法,进一步证明了所提算法的有效性。展开更多
基金supported by the National Natural Science Foundation of China (No. 51208231)
文摘A novel method based on the selective pressure of particle size (particle-size cultivation method, PSCM) was developed for the cultivation and operation of aerobic granular sludge in a continuous-flow reactor, and compared with the conventional method based on the selective pressure of settling velocity (settling-velocity cultivation method, SVCM). Results indicated that aerobic granules could be cultivated in continuous operation mode by this developed method within 14 days. Although in the granulation process, under particle-size selective pressure, mixed liquor suspended solids (MLSS) in the reactor fluctuated greatly and filamentous bacteria dominated the sludge system during the initial operation days, no obvious difference in profile was found between the aerobic granules cultivated by PSCM and SVCM. Moreover, aerobic granules cultivated by PSCM presented larger diameter, lower water content and higher specific rates of nitrification, denitrifieation and phosphorus removal, but lower settling velocity. Under long term operation of more than 30 days, aerobic granules in the continuous-flow reactor could remain stable and obtain good chemical oxygen demand (COD), NH4^+-N, total nitrogen (TN) and total phosphorus (TP) removal. The results indicate that PSCM was dependent on the cultivation and maintenance of the stability of aerobic granules in continuous-flow bioreactors.
文摘Contamination between batches in multi-products pipeline transport is studied. The influences of convection and diffusion on the contamination are studied in detail. Diffusion equations, which are mainly controlled by convection, are developed under turbulent pipe flow. The diffusion equation is separated into a pure convection equation and a pure diffusion equation which are solved by characteristics method and finite difference method respectively to obtain numerical solutions. The results of numerical computation explain the forming and developing of contamination very well.
文摘<div style="text-align:justify;"> <span style="font-family:Verdana;">The aim of this work was to use fish processing waste (FW) as main substrate for anaerobic digestion. To enhance the biogas production of FW, co-digestion was done with two other substrates: cow dung (CD) and waste of market (MW). Batch test was carried out in an 1</span><span "=""><span style="font-family:Verdana;"> L glass digester in a temperature controlled chamber at 38</span><span style="color:#4F4F4F;font-family:Verdana;">°</span><span style="font-family:Verdana;">C. The following mixtures were carried out: FW with CD respectively at different ratios 100:0% (A), 80:20%</span></span><span "=""> </span><span "="" style="font-family:Verdana;">(B) and 60:40% (C);FW with MW at the following ratio 80:20% (D);FW with CD and MW respectively at these ratios 80:10:10% (F) and 60:20:20% (G). The biogas produced was measured using a milligas counter</span><sup><span style="color:#4F4F4F;"><span style="color:#4F4F4F;font-family:Verdana;">®</span><span style="font-family:Verdana;"></span></span></sup><span "="" style="font-family:Verdana;"> and the volume of gas was recorded. The gas composition was determined using gas chromatography. With a pH stable for raw substrates and mixtures, TS and VS (%TS) contents for FW were respectively 31.01% and 91.55%. Between 3 to 13 days of experimentation, the highest flow rate was observed. The percentage of methane was more important for mixtures B and D, 61% and 59% respectively. pH and VOA/T</span><span "="" style="font-family:Verdana;">IC were stable at the end of the batch test for all mixtures, meaning that the organic matter was already well digested. The highest values of Volatile Solid Removal (VSR) were found for mixtures C, D, F and G. Therefore, the promising mixtures for next experimentations in large scale are B and D.</span> </div>
文摘In this paper,a case study is carried out in comparison of pipes-and-filters architecture and batch sequential architecture.Concepts on a data flow system and the two mentioned architectures are presented.A Java template class design in implementing the "pipes" and "filters" in the pipes-and-filters architecture is given at the design level.Finally,this paper uses a concrete example to show how to use Java to implement the pipesand-filters architecture.Using varied amount of data from text files,performance and memory usage of the two architectures are illustrated.
文摘充分考虑实际生产过程中的批量生产形式,构建以最小最大完工时间为目标的置换流水车间分批调度问题的数学模型,并提出一种改进的人工兔优化算法。在编码阶段,采用最小位置值(smallest position value,SPV)规则实现连续解向离散解的转变;在解码阶段,采用动态策略对工件进行分批;通过NEH启发式规则改善初始种群的质量;引入差分进化算子提高解的多样性;提出基于交换和逆序的局部搜索策略增强算法跳出局部最优解的能力。将所提算法和其他对比算法对不同规模的算例进行求解,通过消融实验、对比实验、统计检验等证明了算法的有效性。最后对某汽车外饰件厂喷涂车间排产问题进行求解,求解结果优于其他对比算法,进一步证明了所提算法的有效性。