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Influence of glucose feeding on the ligninolytic enzyme production of the white-rot fungus Phanerochaete chrysosporium

ZHOU Xiaoyan, WEN Xianghua, FENG Yan

《环境科学与工程前沿(英文)》 2007年 第1卷 第1期   页码 89-94 doi: 10.1007/s11783-007-0017-1

摘要: The present work studied the influence of glucose feeding on the ligninolytic enzyme production of in a nitrogen-limited (C/N ratio is 56/8.8 mmol/L) medium. Several sets of shaking flask experiments were conducted. The results showed that 2 g/L glucose feeding on the first day of the culture (24 h after the inoculation) stimulated both fungal biomass growth and enzyme production. The manganese peroxidase (MnP) activity was 2.5 times greater than that produced in cultures without glucose feeding. Furthermore, the glucose feeding mode in fed-batch culture was also investigated. Compared to cultures with glucose feeding every 48 h, cultures with glucose feeding of 1.5 g/L (final concentration) every 24 h produced more enzymes. The peak and total yield of MnP activity were 2.7 and 3 times greater compared to the contrast culture, respectively, and the enzyme was kept stable for 4 days with an activity of over 200 U/L.

关键词: enzyme production     fed-batch culture     nitrogen-limited     inoculation     mmol/L    

Statistical modeling and optimization for enhanced hyaluronic acid production by batch culture of Sreptococcus

Long LIU, Haiquan YANG, Guocheng DU, Miao WANG, Jian CHEN,

《化学科学与工程前沿(英文)》 2009年 第3卷 第4期   页码 351-356 doi: 10.1007/s11705-009-0248-8

摘要: This work is aimed to achieve the optimal hyaluronic acid (HA) production by batch culture of via the supplement of nucleotide bases using response surface methodology (RSM). First, the influence of nucleotide bases (adenine, guanine, cytosine, thymine, and uracil) on microbial HA production was investigated using fractional factorial design (FFD). By a 2 FFD, uracil was found to be the most significant factor for cell growth and HA production, while the other nucleotide bases were shown to have no significant effects on cell growth and HA production. Also, the impact of uracil on cell growth and HA production was further investigated by RSM, where two variables were considered: uracil concentration and supplement time. The optimal uracil concentration and supplement time were found to be 0.051g/L and 7h, respectively, and the predicted maximal HA production reached 6.42g/L. The maximal HA production increased from 5.0g/L of the control without uracil supplement to 6.31g/L at the optimal conditions in validation experiments.

关键词: control     microbial HA     thymine     influence     culture    

科技自主创新与中西文化互补之我见——六个典型实例的思考

李世煇

《中国工程科学》 2005年 第7卷 第4期   页码 11-21

摘要:

从中西文化互补的角度,考察了20世纪70年代以来中国科技原始性自主创新的六个典型实例,简述了笔者从事典型信息法研究的几点认识,试图以事实论证:中国传统文化对当代科技自主创新有重大作用,并对其表现形式等做了初步考察。

关键词: 中国传统文化     西方文化     互补     科技自主创新     典型实例    

Key stakeholders’ perspectives on the ideal partnering culture in construction projects

Gunnar J. LÜHR, Marian G. C. BOSCH-REKVELDT, Mladen RADUJKOVIC

《工程管理前沿(英文)》 2022年 第9卷 第2期   页码 312-325 doi: 10.1007/s42524-020-0135-z

摘要: This paper examines the current state of project cultures in the German turnkey construction industry and the ideal project cultures in terms of partnering from the perspective of various key stakeholders (i.e., Investors, General Contractors, (Sub-)Contractors and Designers). To investigate the current and ideal cultures, data were gathered among the key stakeholders by means of a survey study with 72 respondents divided over 12 companies. The respondents rated the current and desired cultures by using the Organizational Culture Assessment Instrument, which belongs to the Competing Values Framework. The investigations show many similarities and differences between the stakeholder perspectives of the current and the idealized partnering project cultures. Mainly, the General Contractors desire more cooperative behaviors than the (Sub-)Contractors, and the Investors desire more pronounced flexibility than the General Contractors. All stakeholders desire a cultural change from highly competitive behaviors toward more cooperation. Changes in terms of clear procedures or more flexibility are only desired by the Designers. Defining both the current and an ideal partnering project culture enables academics and project managers to compare their actual project cultures to an ideal situation. With such an approach, academics and project managers could measure whether new tools or changes in resources affect their project cultures toward a partnering project culture.

关键词: project culture     organisational culture     partnering     construction culture     stakeholder perspectives     German    

The energy consumption in a batch stripper and a batch rectifier

Xianbao CUI, Tianyang FENG, Ying ZHANG, Zhicai YANG,

《化学科学与工程前沿(英文)》 2009年 第3卷 第4期   页码 443-452 doi: 10.1007/s11705-009-0266-6

摘要: The energy consumption in a batch rectifier and a batch stripper was investigated with a shortcut mathematical model. The minimum energy consumption of a batch stripper was compared to that of a batch rectifier under “general constant reflux” and “general constant distillate composition” with the ratio of minimum energy consumption /. When the feed contains a large amount of light component, the product purity specification is low and the relative volatility is small, the minimum energy consumption of a batch stripper is less than that of a batch rectifier under “general constant reflux” and “general constant distillate composition”. When the feed contains a small amount of light component, the product purity specification is very high and the relative volatility is low, a batch stripper can also consume less energy only in the “general constant distillate composition” operation mode. In other cases, a batch rectifier can consume less energy.

关键词: constant reflux     feed     energy consumption     general constant     product purity    

Influence of entrainer recycle for batch heteroazeotropic distillation

Laszlo Hegely, Peter Lang

《化学科学与工程前沿(英文)》 2018年 第12卷 第4期   页码 643-659 doi: 10.1007/s11705-018-1760-5

摘要:

Dehydration of isopropanol applying batch heteroazeotropic distillation with toluene as entrainer (E) is investigated. The composition of the feed is near to that of the isopropanol (A)-water (B) azeotrope. The effects of recycling the entrainer and the off-cut are studied by dynamic simulation with a professional flow-sheet simulator. Three consecutive batches (one production cycle) is studied. Both operational modes (Mode I: decantation after distillation and Mode II: decantation during distillation) are simulated. For Mode II, calculations are performed both for Strategy A (distillate from the aqueous (E-lean) phase only) and Strategy B (partial withdrawal of the organic (E-rich phase), as well). The E-rich phase, the final column hold-up and the off-cut (Mode II only) are recycled to the next batch. The influence of the following parameters are determined: quantity of entrainer, reflux ratios of the steps. The variations caused by the recycling in the 2nd and 3rd batches are also shown. The best results (lowest specific energy demand and highest recovery of A) are obtained by Mode II, Strategy A. Recycling increases the recovery, and drastically diminishes the entrainer consumption. However, it makes the production slower and decreases the quantity of fresh feed that can be processed.

关键词: batch distillation     heteroazeotropic distillation     operational policies     off-cut recycle     entrainer    

Performance and bioparticle growth of anaerobic baffled reactor (ABR) fed with low-strength domestic

Jing FENG,Yili WANG,Xueyuan JI,Dongqin YUAN,Hui LI

《环境科学与工程前沿(英文)》 2015年 第9卷 第2期   页码 352-364 doi: 10.1007/s11783-014-0638-0

摘要: We investigated the performance of a 15.3 L capacity anaerobic baffled reactor (ABR) toward the treatment of low-strength domestic wastewater. The start-up period of the ABR was finished within approximately 130 days at a temperature below 25°C. The average COD in the effluent was 165 mg·L , and the corresponding COD removal efficiency of the ABR was 52.3%. During the third stage (from day 130 to day 233) of ABR operation, the average COD in the effluent reached 71 mg·L , which meets the secondary discharge requirement of the Integrated Wastewater Discharge Standard (GB 18918-2002, China). Moreover, partial microbial separation was observed along the five ABR compartments through scanning electron microscopic images. The geometric mean diameter of bioparticles in the five compartments increased from 0.050 mm to 0.111, 0.107, 0.104, 0.110, and 0.103 mm during the start-up stage. After operation for 179 days, the corresponding diameters further increased to 0.376, 0.225, 0.253, 0.239, and 0.288 mm, respectively. The fractal dimensions of the bioparticles indicated that these particles have smoother surfaces and more compact structures during ABR operation. Morphological analysis of the bioparticle sections demonstrated that the bioparticles have a pore volume of 30%–55%. The highest porosity was observed for the bioparticles in the second ABR compartment, whereas the lowest fractal dimension of bioparticle section was observed in the fifth compartment.

关键词: low-strength domestic wastewater     start-up     bioparticles     morphology     anaerobic baffled reactor    

Doubly-fed induction generator drive based WECS using fuzzy logic controller

Abdelhak DIDA,Djilani BEN ATTOUS

《能源前沿(英文)》 2015年 第9卷 第3期   页码 272-281 doi: 10.1007/s11708-015-0363-9

摘要: The purpose of this paper is to improve the control performance of the variable speed, constant frequency doubly-fed induction generator in the wind turbine generation system by using fuzzy logic controllers. The control of the rotor-side converter is realized by stator flux oriented control, whereas the control of the grid-side converter is performed by a control strategy based on grid voltage orientation to maintain the DC-link voltage stability. An intelligent fuzzy inference system is proposed as an alternative of the conventional proportional and integral (PI) controller to overcome any disturbance, such as fast wind speed variation, short grid voltage fault, parameter variations and so on. Five fuzzy logic controllers are used in the rotor side converter (RSC) for maximum power point tracking (MPPT) algorithm, active and reactive power control loops, and another two fuzzy logic controllers for direct and quadratic rotor currents components control loops. The performances have been tested on 1.5 MW doubly-fed induction generator (DFIG) in a Matlab/Simulink software environment.

关键词: fuzzy logic     wind turbine     vector control     doubly-fed induction generator (DFIG)    

Micromixing performance of the teethed high shear mixer under semi-batch operation

《化学科学与工程前沿(英文)》 2022年 第16卷 第4期   页码 546-559 doi: 10.1007/s11705-021-2069-3

摘要: Semi-batch operated reaction processes are necessary for some competitive reaction systems to achieve a desirable process selectivity and productivity of fine chemical products. Herein the structural and operating parameters of the teethed high shear mixers were adjusted to study the micromixing performance in the semi-batch operated system, using the Villermaux/Dushman reaction system. The results indicate that the rising of the rotor speed and the number of rotor teeth, the decrease of the width of the shear gap and the radial distance between the feed position and the inner wall of stator can enhance the micromixing level and lead to the decrease of the segregation index. Additionally, computational fluid dynamics calculations were carried out to disclose the evolution of the flow pattern and turbulent energy dissipation rate of the semi-batch operated high shear mixer. Furthermore, the correlation was established with a mean relative error of 8.05% and R2 of 0.955 to fit the segregation index and the parameters studied in this work, which can provide valuable guidance on the design and optimization of the semi-batch operated high shear mixers in practical applications.

关键词: high shear mixer     semi-batch operation     micromixing performance     Villermaux/Dushman system     segregation index    

Two-stage scheduling on batch and single machines with limited waiting time constraint

Zhongshun SHI, Zewen HUANG, Leyuan SHI

《工程管理前沿(英文)》 2017年 第4卷 第3期   页码 368-374 doi: 10.15302/J-FEM-2017034

摘要: This study addresses the problem of two-stage scheduling on batch and single machines with limited waiting time constraint; thus, the makespan is minimized. A mixed-integer linear programming model is proposed for this problem. Three tight lower bounds and a heuristic algorithm are developed. The worst-case performance of the proposed algorithm is discussed. A hybrid differential evolution algorithm is also developed to improve the solution quantity. Numerical results show that the hybrid algorithm is capable of obtaining high-quality solutions and exhibits a competitive performance

关键词: batch machine     flow shop     makespan     limited waiting time    

Mixed culture of

Kishore Gopalakrishnan, Javad Roostaei, Yongli Zhang

《环境科学与工程前沿(英文)》 2018年 第12卷 第4期 doi: 10.1007/s11783-018-1075-2

摘要:

RSM is used to explore the impact of different parameter on algal growth response.

Mixed algal culture promotes algal biomass and lipid accumulation.

Optimized conditions achieve maximum productivity of algal biomass and lipid.

关键词: Algal biofuels     Algal mixed cultures     Algal biomass     Algal lipid     Wastewater     Response surface methodology    

Robust control based on the Lyapunov theory of a grid-connected doubly fed induction generator

Ridha CHEIKH, Arezki MENACER, Said DRID

《能源前沿(英文)》 2013年 第7卷 第2期   页码 191-196 doi: 10.1007/s11708-013-0245-y

摘要: This paper discusses the robust control of a grid-connected doubly-fed induction generator (DFIG) controlled by vector control using a nonlinear feedback linearization strategy in order to ameliorate the performances of the control and to govern the developed stator active and reactive power in a linear and decoupled manner, in which an optimal operation of the DFIG in sub-synchronous operation is given, as well as the control stator power flow with the possibility of keeping stator power factor at a unity. The use of the state-all-flux induction machine model gives place to a simpler control model. So, to achieve this objective, the Lyapunov approach is used associated with a sliding mode control to guarantee the global asymptotical stability and the robustness of the parametric variations.

关键词: doubly fed induction generator (DFIG)     vector control     Lyapunov function     power factor unity     active power     reactive power    

Repeated batch fermentation with water recycling and cell separation for microbial lipid production

Yumei WANG, Wei LIU, Jie BAO

《化学科学与工程前沿(英文)》 2012年 第6卷 第4期   页码 453-460 doi: 10.1007/s11705-012-1210-8

摘要: Large waste water disposal was the major problem in microbial lipid fermentation because of low yield of lipid. In this study, the repeated batch fermentation was investigated for reducing waste water generated in the lipid fermentation of an oleaginous yeast CX1 strain. The waste fermentation broth was recycled in the next batch operation after the cells were separated using two different methods, centrifugation and flocculation. Two different sugar substrates, glucose and inulin, were applied to the proposed operation. The result showed that at least 70% of the waste water was reduced, while lipid production maintained satisfactory in the initial four cycles. Furthermore, it is suggested that CX1 cells might produce certain naturally occurring inulin hydrolyzing enzyme(s) for obtaining fructose and glucose from inulin directly. Our method provided a practical option for reducing the waste water generated from microbial lipid fermentation.

关键词: batch fermentation     microbial lipid     Trichosporon cutaneum CX1     flocculation     waste water recycle    

Multistage-batch bipolar membrane electrodialysis for base production from high-salinity wastewater

《化学科学与工程前沿(英文)》 2022年 第16卷 第5期   页码 764-773 doi: 10.1007/s11705-021-2114-2

摘要: Bipolar membrane electrodialysis (BMED) is considered a state-of-the-art technology for the conversion of salts into acids and bases. However, the low concentration of base generated from a traditional BMED process may limit the viability of this technology for a large-scale application. Herein, we report an especially designed multistage-batch (two/three-stage-batch) BMED process to increase the base concentration by adjusting different volume ratios in the acid (Vacid), base (Vbase), and salt compartments (Vsalt). The findings indicated that performance of the two-stage-batch with a volume ratio of Vacid:Vbase:Vsalt = 1:1:5 was superior in comparison to the three-stage-batch with a volume ratio of Vacid:Vbase:Vsalt = 1:1:2. Besides, the base concentration could be further increased by exchanging the acid produced in the acid compartment with fresh water in the second stage-batch process. With the two-stage-batch BMED, the maximum concentration of the base can be obtained up to 3.40 mol∙L–1, which was higher than the most reported base production by BMED. The low energy consumption and high current efficiency further authenticate that the designed process is reliable, cost-effective, and more productive to convert saline water into valuable industrial commodities.

关键词: bipolar membrane electrodialysis     multistage-batch     base production     high-salinity wastewater    

Microbial community structure and dynamics of starch-fed and glucose-fed chemostats during two years

Min GOU,Jing ZENG,Huizhong WANG,Yueqin TANG,Toru SHIGEMATSU,Shigeru MORIMURA,Kenji KIDA

《环境科学与工程前沿(英文)》 2016年 第10卷 第2期   页码 368-380 doi: 10.1007/s11783-015-0815-9

摘要: The microbial community structures of two mesophilic anaerobic chemostats, one fed with glucose, the other with starch as sole carbon sources, were studied at various dilution rates (0.05–0.25 d for glucose and 0.025–0.1 d for starch) during two years continuous operation. In the glucose-fed chemostat, the aceticlastic methanogen spp. and hydrogenotrophic methanogen spp. predominated at low dilution rates, whereas spp. and the hydrogenotrophic spp. predominated together when dilution rates were greater than 0.1 d . Bacteria affiliated with the phyla Bacteroidetes, Spirochaetes, and Actinobacteria predominated at dilution rates of 0.05, 0.1, and 0.15 d , respectively, while Firmicutes predominated at higher dilution rates (0.2 and 0.25 d ). In the starch-fed chemostat, the aceticlastic and hydrogenotrophic methanogens coexisted at all dilution rates. Although bacteria belonging to only two phyla were mainly responsible for starch degradation (Spirochaetes at the dilution rate of 0.08 d and Firmicutes at other dilution rates), different bacterial genera were identified at different dilution rates. With the exception of Archaea in the glucose-fed chemostat, the band patterns revealed by denaturing gradient gel electrophoresis (DGGE) of the microbial communities in the two chemostats displayed marked changes during long-term operation at a constant dilution rate. The bacterial community changed with changes in the dilution rate, and was erratic during long-term operation in both glucose-fed and starch-fed chemostats.

关键词: microbial community     glucose degradation     starch degradation     dilution rate     continuous methane fermentation     phylogenetic analysis    

标题 作者 时间 类型 操作

Influence of glucose feeding on the ligninolytic enzyme production of the white-rot fungus Phanerochaete chrysosporium

ZHOU Xiaoyan, WEN Xianghua, FENG Yan

期刊论文

Statistical modeling and optimization for enhanced hyaluronic acid production by batch culture of Sreptococcus

Long LIU, Haiquan YANG, Guocheng DU, Miao WANG, Jian CHEN,

期刊论文

科技自主创新与中西文化互补之我见——六个典型实例的思考

李世煇

期刊论文

Key stakeholders’ perspectives on the ideal partnering culture in construction projects

Gunnar J. LÜHR, Marian G. C. BOSCH-REKVELDT, Mladen RADUJKOVIC

期刊论文

The energy consumption in a batch stripper and a batch rectifier

Xianbao CUI, Tianyang FENG, Ying ZHANG, Zhicai YANG,

期刊论文

Influence of entrainer recycle for batch heteroazeotropic distillation

Laszlo Hegely, Peter Lang

期刊论文

Performance and bioparticle growth of anaerobic baffled reactor (ABR) fed with low-strength domestic

Jing FENG,Yili WANG,Xueyuan JI,Dongqin YUAN,Hui LI

期刊论文

Doubly-fed induction generator drive based WECS using fuzzy logic controller

Abdelhak DIDA,Djilani BEN ATTOUS

期刊论文

Micromixing performance of the teethed high shear mixer under semi-batch operation

期刊论文

Two-stage scheduling on batch and single machines with limited waiting time constraint

Zhongshun SHI, Zewen HUANG, Leyuan SHI

期刊论文

Mixed culture of

Kishore Gopalakrishnan, Javad Roostaei, Yongli Zhang

期刊论文

Robust control based on the Lyapunov theory of a grid-connected doubly fed induction generator

Ridha CHEIKH, Arezki MENACER, Said DRID

期刊论文

Repeated batch fermentation with water recycling and cell separation for microbial lipid production

Yumei WANG, Wei LIU, Jie BAO

期刊论文

Multistage-batch bipolar membrane electrodialysis for base production from high-salinity wastewater

期刊论文

Microbial community structure and dynamics of starch-fed and glucose-fed chemostats during two years

Min GOU,Jing ZENG,Huizhong WANG,Yueqin TANG,Toru SHIGEMATSU,Shigeru MORIMURA,Kenji KIDA

期刊论文