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1.
Jeong-Woo Choi Jin Man Cho Jung Gun Lee Won Hong Lee Ik Hwan Kim Young Hoon Park 《Korean Journal of Chemical Engineering》1998,15(4):404-410
A self-organizing fuzzy controller is constructed for control of substrate concentration in fed-batch operation of a cell
culture process. A genetic algorithm is used to generate fuzzy rules of the self-organizing fuzzy controller and to modify
the universe of discourse automatically. The fuzzy controller is designed for the application ofScutellaria baicalensis G. plant cell culture process as a model system. A substrate feeding strategy of a two stage culture method to maximize flavone
glycoside production in fed-batch culture ofScutellaria baicalensis G. plant cell is proposed based on structured model of growth and product synthesis. As a two stage culture, the feeding strategy
consists of the first period at 22 g/L of glucose concentration to promote cell growth and the second period at 10 g/L of
glucose concentration to promote flavone glycoside synthesis. The designed self-organizing fuzzy controller is applied to
regulate the glucose concentration at a given set-point to increase flavone glycoside synthesis. The simulation results show
that the proposed feeding strategy in a fed-batch culture enhances flavone glycoside production and the self-organizing fuzzy
logic controller generated by genetic algorithm improves controller performance. 相似文献
2.
提出一种以分子量分布为目标的聚酯工业生产过程流程模拟方法,针对通用流程模拟软件Aspen Plus在逐步聚合(step-growth)反应机理下不能计算分子量分布指数和分子量分布曲线的不足,通过外置接口程序从后台运行的Aspen源文件(*.bkp/*.apw)中读取数据,实现分子量分布曲线的可视化和其他质量指标的计算。以聚对苯二甲酸丁二醇酯(PBT)工业生产中的预缩聚过程为建模实例,在Aspen Polymers Plus软件平台上建立基于严格过程机理的聚酯工业预缩过程框架模型。根据分子量及端羧基浓度随动力学参数变化的灵敏度,利用工业操作参数及分析数据整定动力学参数,进一步通过外置接口程序计算PBT的分子量分布,重均分子量、分子量分布指数误差分别为4.2%、5.6%,为聚酯生产过程的分子量分布可视化提供基础。 相似文献
3.
Evaluation of fluorescent dyes to measure protein aggregation within mammalian cell culture supernatants
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Sheun Oshinbolu Rachana Shah Gary Finka Mike Molloy Mark Uden Daniel G Bracewell 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2018,93(3):909-917
BACKGROUND
A current challenge in bioprocessing is the ability to analyse critical quality attributes such as aggregation without prior purification. This study evaluated the use of fluorescent dyes (Bis‐ANS, SYPRO Orange, Thioflavin T and ProteoStat) to characterise mAb aggregates in Chinese hamster ovary clarified cultures.RESULTS
The null and mAb culture supernatants showed an increase in fluorescence intensity over the duration of the culture. The null cultures on day 14 saw a rapid increase in fluorescence intensity; day 10 to day 14, Bis‐ANS and Thioflavin T had average increases of 21% and 48%, respectively, whereas ProteoStat and SYPRO Orange showed an average increase of 60%. Higher fluorescence intensity on day 14 with the null cultures, also correlated with loss of viability.CONCLUSION
Fluorescent dyes are not a specific indicator of mAb aggregation, but rather an indicator of overall protein aggregation or high molecular weight species. SYPRO Orange was more sensitive at detecting very large molecular weight species and ProteoStat seemed better suited to smaller aggregates. Although the assay cannot be used to measure mAb aggregates in cell culture, it could be used to aid cell line selection in maximising viabilities and minimising the amount of aggregates. © 2017 The Authors. Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. 相似文献4.
Mauro Moresi Delfo Cimarelli Giuliana Gasparrini Giuseppe Liuzzo Roberto Marinelli 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1980,30(1):266-277
In this work, yeast of the genus Candida was screened by means of shaken-flask and jar fermentations. Two strains, Candida lipolytica Cooper and ATCC 8661, were selected. Their citric acid productivity was 0.79 and 0.67 g g?1 of n-paraffins consumed, respectively, and their citric: total citric and isocitric acid ratios ranged from 0.82 to 0.93, respectively. The experimental results (cell growth and total citric and isocitric acid formation) were described by using an unstructured kinetic model which has been proposed previously (standard error was less than 10%). Moreover, each independent kinetic parameter was correlated with the aeration rate of the culture medium by means of empirical regressions. Aeration of the culture medium showed a large influence on the product yield. For instance, the strain C. lipolytica Cooper exhibited the highest productivity among the examined strains, associated with the largest air consumption. 相似文献
5.
Although there are several kinetic models for the production of phthalic anhydride from the partial oxidation of o‐xylene, only few studies have compared the effect of the kinetic model on the prediction of the hot‐spot temperature. In this work, the predicted temperature profile for the partial oxidation of o‐xylene to phthalic anhydride in a multitubular packed bed reactor was obtained for different kinetic mechanisms using one‐dimensional pseudo‐homogeneous and heterogeneous models. The predicted temperature profile using the one‐dimensional heterogeneous model with the kinetic model of Calderbank et al. but with the adjusted kinetic and transport parameters proposed by Anastasov presented a good correlation with regard to experimental data. Nevertheless, in the hot‐spot zone deviations, up to 30 K were presented. In conclusion, the temperature performance in the production of phthalic anhydride is suitably predicted by the one‐dimensional heterogeneous model and the Calderbank et al.'s kinetic model. Though, prediction using bidimensional models should be done to establish the best correlation with experimental data. 相似文献
6.
Stela Jokić Sandra Svilović Zoran Zeković Senka Vidović Darko Velić 《European Journal of Lipid Science and Technology》2011,113(5):644-651
Supercritical CO2 extraction of soybean oil was investigated. The fatty acid composition was determined using GC. The solubility and kinetic experiments were performed in the pressure range of 100–300 bar and in the temperature range of 313–323 K. The solubility data were correlated using empirical equation proposed by Gordillo et al. Mass transfer model described by Martinez et al. was used to describe the kinetic curves of soybean oil. The main fatty acids of soybean oil were linoleic, oleic, palmitic, stearic and linolenic acid. The improved Gordillo et al. equation was proposed to correct the effect of temperature on the solubility. The new equation was successfully applied for calculating the solubility of fatty acids and soybean oil in supercritical CO2. 相似文献
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A mathematical model of the batch acetone-butanol fermentation has been proposed which reflects the process kinetics and biochemistry. The degree of importance of the key kinetic parameters has been established by a parametric sensitivity analysis. The basic model was further extended by incorporating additional culture physiological parameters such as the number of active mass transport sites and the permeability of the cellular membrane as well as the intracellular and extracellular conditions. The model assisted in studying the role of the cellular membrane in the control of the culture performance and solvent biosynthesis. The theoretical predictions were confirmed by experimental results. 相似文献
10.
The paper gives an analysis of the data reported by J. D. Cooney and others. [J. Appl. Polym. Sci., 29 , 911 (1984)] on the kinetics of oxidative degradation of flame-retardant polyesters [poly(ethylene terephthalate)]. A linear correlation is shown to exist between the parameters of the kinetic compensation effect. A formal interpretation of the correlation is given as well as its interpretation within two alternative polyester degradation schemes. The above correlation allowed the invariant kinetic parameters of the process log  = 15.7±1.3;Ê = 183±16 (min?1; kJ/mol) to be estimated, which seem to characterize the destruction of the polyester bond in the presence of oxygen. It is shown that  and Ê may be used to characterize the kinetics of polyester oxidative degradation during combustion, while the compensation parameter T?; may characterize the flame-retardant effect. 相似文献
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12.
采用三维荧光光谱法对城市污水二级处理工艺出水进行了光谱表征。研究结果表明,各处理单元出水的光谱图均呈现出明显的类色氨酸峰(T峰)和类富里酸峰(M峰),T峰荧光强度随处理过程逐渐减弱,M峰荧光强度变化不明显。当污水厂接纳垃圾渗滤液废水时,T峰和M峰的荧光强度异常显著。不同月份最终出水的类色氨酸(Ex/Em=280/340 nm处)荧光强度值分别下降了47.2%、56.4%和67.4%。类色氨酸荧光强度值与CODCr浓度呈线性正相关(R2=0.858)。该研究提供了一种简便、快速、有效的污水监测方法。 相似文献
13.
Won-Bok Chae Young-Bum Kim Sung-Won Choi Hyang-Bok Lee Eun-Ki Kim 《Korean Journal of Chemical Engineering》2009,26(2):438-443
To be an effective microbial biocide, Streptomyces kasugaensis should be converted into spore during cultivation process for successful long-term storage. By statistical design methods,
culture conditions including medium components and operating parameters were optimized and more than 100 times increase in
spore yield was achieved. Addition of spent culture fluid (100 ppm), EDTA (30 ppm), mycophenolic acid (32 ppm) with combination
of pH up-shock (5.5 to 8.5) increased total viable cell and spore conversion rate, resulting in 1.6×107 (spore/mL) in 5 days of culture in a fermenter. This result provides a practical method for obtaining high spore number for
commercial production of Streptomyces kasugaensis as a microbial pesticide. 相似文献
14.
Catalytic combustion kinetics of isopropanol over novel porous microfibrous‐structured ZSM‐5 coating/PSSF catalyst
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Huanhao Chen Ying Yan Yan Shao Huiping Zhang Huanhao Chen 《American Institute of Chemical Engineers》2015,61(2):620-630
Porous thin‐sheet cobalt–copper–manganese mixed oxides modified microfibrous‐structured ZSM‐5 coating/PSSF catalysts were developed by the papermaking/sintering process, secondary growth process, and incipient wetness impregnating method. Paper‐like sintered stainless steel fibers (PSSF) support with sinter‐locked three‐dimensional networks was built by the papermaking/sintering process, and ZSM‐5 coatings were fabricated on the surface of stainless steel fibers by the secondary growth process. Catalytic combustion performances of isopropanol at different concentrations over the microfibrous‐structured Co–Cu–Mn (1:1:1)/ZSM‐5 coating/PSSF catalysts were measured to obtain kinetics data. The catalytic combustion kinetics was investigated using power–rate law model and Mars–Van Krevelen model. It was found that the Mars–Van Krevelen model provided fairly good fits to the kinetic data. The catalytic combustion reaction occurred by interaction between isopropanol molecule and oxygen‐rich centers of modified microfibrous‐structured ZSM‐5 coating/PSSF catalyst. The reaction activation energies for the reduction and oxidation steps are 60.3 and 57.19 kJ/mol, respectively. © 2014 American Institute of Chemical Engineers AIChE J, 61: 620–630, 2015 相似文献
15.
Modeling and process simulation of hollow fiber membrane reactor systems for propane dehydrogenation
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Seung‐Won Choi David S. Sholl Sankar Nair Jason S. Moore Yujun Liu Ravindra S. Dixit John G. Pendergast 《American Institute of Chemical Engineers》2017,63(10):4519-4531
We report a detailed modeling analysis of membrane reactor systems for propane dehydrogenation (PDH), by integrating a two‐dimensional (2‐D) nonisothermal model of a packed bed membrane reactor (PBMR) with ASPEN process simulations for the overall PDH plant including downstream separations processes. PBMRs based on ceramic hollow fiber membranes—with catalyst placement on the shell side—are found to be a viable route, whereas conventional tubular membranes are prohibitively expensive. The overall impact of the PBMR on the PDH plant (e.g., required dimensions, catalyst amount, overall energy use in reaction and downstream separation) is determined. Large savings in overall energy use and catalyst amounts can be achieved with an appropriate configuration of PBMR stages and optimal sweep/feed ratio. Overall, this work determines a viable design of a membrane reactor‐based PDH plant and shows the potential for miniaturized hollow‐fiber membrane reactors to achieve substantial savings. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4519–4531, 2017 相似文献
16.
Liang Shen Zhongtao An Qingbiao Li Chuanyi Yao Yajuan Peng Yuanpeng Wang Ruihua Lai Xu Deng Ning He 《中国化学工程学报》2015,23(1):219-226
Fermentation of bioflocculant with Corynebacterium glutamicum was studied by way of kinetic modeling. Lorentzian modified Logistic model, time-corrected Luedeking–Piret and Luedeking–Piret type models ... 相似文献
17.
Fermentation of bioflocculant with Corynebacterium glutamicum was studied by way of kinetic modeling. Lorentzian modified Logistic model, time-corrected Luedeking–Piret and Luedeking–Piret type models were pro-posed and applied to describe the cell growth, bioflocculant synthesis and consumption of substrates, with the correlation of initial biomass concentration and initial glucose concentration, respectively. The results showed that these models could well characterize the batch culture process of C. glutamicum at various initial glucose con-centrations from 10.0 to 17.5 g·L?1. The initial biomass concentration could shorten the lag time of cel growth, while the maximum biomass concentration was achieved only at the optimal initial glucose concentration of 16.22 g·L?1. A novel three-stage fed-batch strategy for bioflocculant production was developed based on the model prediction, in which the lag phase, quick biomass growth and bioflocculant production stages were sequentially proceeded with the adjustment of glucose concentration and dissolved oxygen. Biomass of 2.23 g·L?1 was obtained and bioflocculant concentration was enhanced to 176.32 mg·L?1, 18.62% and 403.63%higher than those in the batch process, respectively, indicating an efficient fed-batch culture strategy for bioflocculant production. 相似文献
18.
Felipe Ramon-Portugal Marie-Line Delia-Dupuy Herv Pingaud Jean Pierre Riba 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1997,68(2):195-201
This paper deals with the study of the kinetics of batch fermentations for a sensitive strain of S. cerevisiae growing in a culture medium containing K2 killer protein. The inhibition due to the killer toxin was measured by the reduction of the viable biomass, ethanol production and glucose consumption compared with a reference fermentation. The reference culture was run under the same conditions, but using a heat-denatured solution of killer protein. Results showed a decrease of the viable population of 67·8% after 15 h incubation. The fermentation time for the total consumption of the glucose was significantly affected by the presence of the killer toxin. The specific rate of ethanol production was also affected during the fermentation. However, the yields of ethanol and biomass were very similar for both fermentations. A kinetic mathematical model was proposed to explain the dynamics of the S. cerevisiae 522D growth in the presence of the K2 killer protein. The results of the suggested simulation were in agreement with the experimental data. © 1997 SCI. 相似文献
19.
Seyyed Hossein Hosseini Saeed Shojaee Goodarz Ahmadi Mortaza Zivdar 《Journal of Industrial and Engineering Chemistry》2012,18(4):1465-1473
Computational fluid dynamics was used to study the hydrodynamic of structured packings. The results showed that the k–ω was a suitable turbulence model for analyzing the flows in structured packings. A simple method was proposed for evaluating the liquid holdup based on the Iliuta and Larachi (2001) model [25], the calculated liquid film thickness in 2D framework, and the empirical correlation of Brito et al. (1994) [26]. The presented method can be used for estimating the wet pressure drop in 3D structured packings for loading region with good accuracy as well as computational economy. The process of liquid film formation was also discussed. 相似文献
20.
A method for quantitative evaluation of kinetic constants in Ziegler–Natta and metallocene olefin polymerizations is presented. The method comprises some fundamental steps, which include the initial design of a statistical experimental plan, the execution of the designed experiments, the development of simple mathematical models to describe the polymerization, and the estimation of kinetic parameters from available rate, gel permeation chromatography, and NMR data. The method is applied to the slurry propylene polymerization, using a conventional first generation Ziegler–Natta catalyst, in a lab‐scale polymerization reactor. It is shown that the proposed method allows the successful interpretation of experimental olefin polymerization data and the quantitative evaluation of kinetic constants, which can be inserted into a process simulator to provide an accurate picture of actual industrial plant behavior. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 79: 2076–2108, 2001 相似文献