Improved Ethanol Production in Jerusalem Artichoke Tubers by Overexpression of Inulinase Gene in Kluyveromyces marxianus

WenJie Yuan,Xinqing Zhao,Li-Jie Chen,Feng-Wu Bai 한국생물공학회 2013 Biotechnology and Bioprocess Engineering Vol.18 No.4

Ethanol production from Jerusalem artichoke tubers through a consolidated bioprocessing (CBP) strategy using the inulinase-producing yeast Kluyveromyces marxianus is an economical and competitive than that from a grainbased feedstock. However, poor inulinase production under ethanol fermentation conditions significantly prolongs the fermentation time and compromises ethanol productivity. Improvement of inulinase activity appears to be promising for increasing ethanol production from Jerusalem artichoke tubers by CBP. In the present study, expression of the inulinase gene INU with its own promoter in K. marxianus (K/INU2) was explored using the integrative cassette. Overexpression of INU was explored using chromosome integration via the HO locus of the yeast. Inulinase activity and ethanol were determined from inulin and Jerusalem artichoke tubers under fed-batch operation. Inulinase activity was 114.9 U/mL under aerobic conditions for K/INU2, compared with 52.3 U/mL produced by the wild type strain. Importantly, inulinase production was enhanced in K/INU2 under ethanol fermentation conditions. When using 230 g/L inulin and 220 g/L Jerusalem artichoke tubers as substrates, inulinase activities of 3.7 and 6.8 U/mL,respectively, were measured using K/INU2, comparing favorably with 2.4 and 3.1 U/mL, respectively, using the wide type strain. Ethanol concentration and productivity for inulin were improved by the recombinant yeast to 96.2 g/L and 1.34 g/L/h, respectively, vs 93.7 g/L and 1.12 g/L/h,respectively, by the wild type strain. Ethanol concentration and productivity improvements for Jerusalem artichoke tubers were 69 g/L and 1.44 g/L/h, respectively, from the recombinant strain vs 62 g/L and 1.29 g/L/h, respectively,from the wild type strain.

Application of different surrogate models on the optimization of centrifugal pump

Wenjie Wang,Ji Pei,Shouqi Yuan,Jinfeng Zhang,Jian-Ping Yuan,Changzheng Xu 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.2

An optimization process for impellers was carried out based on numerical simulation, Latin hypercube sampling (LHS), surrogate model and Genetic algorithm (GA) to improve the efficiency of residual heat removal pump. The commercial software ANSYS CFX 14.5 was utilized to solve the Reynolds-averaged Navier-Stokes equations by using the Shear stress transport turbulence model. The impeller blade parameters, which contain the blade inlet incidence angle ∆β, blade wrap angle φ, and blade outlet angle β 2 , were designed by random sample points according to the LHS method. The efficiency predicted under the design flow rate was selected as the objective function. The best combination of parameters was obtained by calculating the surrogate model with the GA. Meanwhile, the prediction accuracies of three surrogate models, namely, Response surface model (RSM), Kriging model, and Radial basis neural network (RBNN), were compared. Results showed that the calculated findings agree with the experimental performance results of the original pump. The RSF model predicted the highest efficiency, while the RBNN had the highest prediction accuracy. Compared with the simulated efficiency of the original pump, the optimization increased efficiency by 8.34% under the design point. Finally, the internal flow fields were analyzed to understand the mechanism of efficiency improvement. The optimization process, including the comparison of the surrogate models, can provide reference for the optimization design of other pumps.

A green ultrasound-assisted enzymatic extraction method for efficient extraction of total polyphenols from Empetrum nigrum and determination of its bioactivities

Yuan Gao,Yutong Shi,Na Miao,Wenxin Xing,Cholil Yun,Shengfang Wang,Wenjie Wang,Huimei Wang 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.109 No.-

In this study, a green and efficient ultrasound-assisted enzymatic extraction (UAEE) method was establishedfor total polyphenols (TPP) extraction from E. nigrum aerial parts. Fractional Factorial design (FFD)was initially implemented for the selection of significant parameters affecting TPP yield and then Box-Behnken design-response surface methodology (BBD-RSM) was employed to optimize the parameters. The optimum extraction conditions for UAEE were as follows: incubation temperature of 38.39 ℃, incubationtime of 3.39 h, tannase of 386.53 U/g of sample (U/g), and cellulase of 224.42 U/g. Under the optimumconditions, the TPP yield was 52.17 ± 0.39 mg/g, which was 1.62 and 1.73 times those of themethods of ultrasound-assisted extraction (UAE) and enzyme-assisted extraction (EAE), respectively. The crude extract was purified by HPD-600 microporous resin, and the purity was improved from8.11% to 22.56%. In addition, the results of antioxidant and antibacterial activity assays showed thatthe purified extract has stronger bioactivities in contrast with the crude extract. This study indicated thatUAEE was an effective technique for the extraction of TPP from the aerial parts of E. nigrum, and TPPextracted by this extraction method could be applied in pharmaceuticals, cosmetics, and food industries.

Energy efficiency optimization of water pump based on heuristic algorithm and computational fluid dynamics

Wang Wenjie,Han Zhenhua,Pei Jin,Pavesi Giorgio,Gong Xiaobo,Yuan Shouqi 한국CDE학회 2023 Journal of computational design and engineering Vol.10 No.1

To reduce the energy consumption of large centrifugal pumps, modified heuristic intelligent algorithms are used to directly optimize the diffuser of centrifugal pumps. Considering the hydraulic efficiency under the design condition as the optimization target, in this study, 14 geometric parameters such as the inlet diameter, outlet diameter, and leading and trailing vane angles of the diffuser are selected as design variables, and the modified particle swam optimization and gravitational search algorithm are used to directly search for optimization in the design space. The performance and loss of internal entropy production of the different models before and after optimization are compared and analyzed in detail. The results show that the global optimization ability of the modified algorithm is improved. The diffuser model changes from cylindrical to twisted, the vane wrap angle increases, and the thickness of the leading edge decreases. Under the design condition, the efficiency of modified particle swarm optimization algorithm solution is increased by 2.75% and modified gravitational search algorithm solution by 2.21%, while the power remains unchanged. Furthermore, the optimization solution has the largest lift efficiency improvement under part-load conditions. After optimization, the unstable flow in the model is improved and internal entropy production loss is reduced significantly. The interior of the diffuser is dominated by turbulent entropy production and direct entropy production under different operating conditions, and the wall entropy production accounts for the smallest proportion.

A Numerical Method to Reduce the Stray Magnetic Field Around the Asymmetrical Wireless Power Transfer Coils for Electric Vehicle Charging

Zhang Wenjie,Song Jiancheng,Lin Lingyan,Ren Hui,Zheng Lijun,Gao Yunguang,Song Yuan 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.3

Wireless power transfer (WPT) is becoming increasingly popular in stationary electric vehicle charging. Unfortunately, the adverse health eff ects due to the stray magnetic fi eld created by the WPT coils have increasingly caused concern. However, the traditional stray magnetic fi eld optimization design method based on fi nite element simulation is time-consuming and resource intensive. In this paper, a numerical method to reduce the stray magnetic fi eld around the asymmetrical wireless power transfer coils is proposed while maintaining the transmission power constant. The formulas of the stray magnetic fi eld around the WPT coils are derived, and the distribution characteristics of the stray magnetic fi eld are analyzed in detail. The stray magnetic fi eld around the asymmetrical wireless power transfer coils is optimized by the numerical method, and the number of the turns for the WPT coils corresponding to the minimum stray magnetic fi eld intensity is obtained. The eff ectiveness of the numerical method is verifi ed via the fi nite element analysis tool JMAG, and it is proved that the numerical method require less computational time than the fi nite element simulation. The experiments have also been carried out to evaluate the validity of the theoretical analysis.

Multi-point optimization on meridional shape of a centrifugal pump impeller for performance improvement

Ji Pei,Wenjie Wang,Shouqi Yuan 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.11

A wide operating band is important for a pump to safely perform at maximum efficiency while saving energy. To widen the operating range, a multi-point optimization process based on numerical simulations in order to improve impeller performance of a centrifugal pump used in nuclear plant applications is proposed by this research. The Reynolds average Navier Stokes equations are utilized to perform the calculations. The meridional shape of the impeller was optimized based on the following four parameters; shroud arc radius, hub arc radius, shroud angle, and hub angle as the design variables. Efficiencies calculated under 0.6Q d , 1.0Q d and 1.62Q d were selected as the three optimized objectives. The Design of experiment method was applied to generate various impellers while 35 impellers were generated by the Latin hypercube sampling method. A Response surface function based on a second order function was applied to construct a mathematical relationship between the objectives and design variables. A multi-objective genetic algorithm was utilized to solve the response surface function to obtain the best optimized objectives as well as the best combination of design parameters. The results indicated that the pump performance predicted by numerical simulation was in agreement with the experimental performance. The optimized efficiencies based on the three operating conditions were increased by 3.9 %, 6.1 % and 2.6 %, respectively. In addition, the velocity distribution, pressure distribution,streamline and turbulence kinetic energy distribution of the optimized and reference impeller were compared and analyzed to illustrate the performance improvement.

On the Pacific Decadal Oscillation Simulations in CMIP6 Models: A New Test‑Bed from Climate Network Analysis

Yiling Ma,Naiming Yuan,Tianyun Dong,Wenjie Dong 한국기상학회 2023 Asia-Pacific Journal of Atmospheric Sciences Vol.59 No.1

As a dominant pattern of the North Pacific sea surface temperature decadal variability, the Pacific Decadal Oscillation (PDO) has remarkable influences on the marine and terrestrial ecosystems. However, the PDO is highly unpredictable. Here, we assess the performance of the Coupled Model Intercomparison Project Phase 6 (CMIP6) models in simulating the PDO, with an emphasis on the evaluation of CMIP6 models in reproducing a recently detected early warning signal based on climate network analysis for the PDO regime shift. Results show that the skill of CMIP6 historical simulations remains at a low level, with a skill limited in reproducing PDO’s spatial pattern and nearly no skill in reproducing the PDO index. However, if the warning signal for the PDO regime shift by climate network analysis is considered as a test-bed, we find that even in historical simulations, a few models can represent the corresponding relationship between the warning signal and the PDO regime shift, regardless of the chronological accuracy. By further conducting initialization, the performance of the model simulations is improved according to the evaluation of the hindcasts from two ensemble members of the Decadal Climate Prediction Project (NorCPM1 and BCC-CSM2-MR). Particularly, we find that the NorCPM1 model can capture the early warning signals for the late-1970s and late-1990s regime shifts 5–7 years in advance, indicating that the early warning signal somewhat can be captured by some CMIP6 models. A further investigation on the underlying mechanisms of the early warning signal would be crucial for the improvement of model simulations in the North Pacific.

Multi-component optimization of a vertical inline pump based on multiobjective pso and artificial neural network

Xingcheng Gan,Ji Pei,Wenjie Wang,Shouqi Yuan,Yajing Tang 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.12

The vertical inline pump is a single-stage single-suction centrifugal pump with a curved inlet pipe before the impeller, which is widely used in where the constraint is installation space. In this paper, with the objective functions of efficiencies at 0.5 , d Q 1.0 , d Q and 1.5 , d Q a multi-objective optimization on inlet pipe and impeller was proposed to broaden the efficient operating period of a vertical inline pump. Two 5th order Bézier curves were adopted to fit the shape of the mid curve of the inlet pipe and the trend of the blade angle of the impeller. Fourteen design variables were selected after the data-mining process. 300 sample cases were generated using Latin hypercube sampling (LHS), and they were solved by 3D RANS code to obtain the objective functions. The feed-forward artificial neural network with a hidden layer and an output layer was adopted to fit the two objective functions and the 14 design variables. The Pareto frontiers were generated for the three objectives using multi-objective particle swarm optimization (MOPSO), and three different configurations on the Pareto front are selected for detailed study by computational fluid dynamics (CFD). The results showed that the profile of the inlet pipe and the blade have a dramatic impact on the performance of the vertical inline pump. The Pareto frontiers reported that the performance under the overload condition usually keeps stable when the nominal efficiency is lower than 82 %, or the part-load efficiency is lower than 62 %, and it will decrease rapidly after that. After optimization, the improvement of efficiencies at the part-load condition and nominal condition of the picked case were 9.65 % and 7.95 %, respectively.

Fluid-structure interaction analysis of an impeller for a high-pressure booster pump for seawater desalination

Tingyun Yin,Ji Pei,Shouqi Yuan,Majeed Koranteng Osman,Jiabin Wang,Wenjie Wang 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.11

A High-pressure booster pump (HPBP) is an essential piece of equipment in a Seawater reverse osmosis (SWRO) system. As the corerotating component in the HPBP, the impeller operates extensively in a high-pressure and corrosive environment and its work status directly affects the reliability of the pump device. The vibration characteristics of the rotor were analyzed using fluid-structure interaction theory to determine the characteristics that would ensure the long-term safe operation of the HPBP. The stress and deformation analysis was performed on a partitioned solution for an impeller in a moving fluid, and the modal analysis of the impeller was conducted in still fluid based on a monolithic solution. The influence of the impeller shroud thickness on the resulting vibration characteristics was investigated by using three modifications of the impeller. A comparison of the results with the initial impeller geometry was then carried out under partial load operations. Three commonly used materials for an impeller were also evaluated. The three-dimensional turbulent flow was modeled utilizing the SST k-ω turbulence model, and the numerical results were verified by the experimental data. The results show that natural frequency of the 20CrMnTi is the highest among the three materials for each order mode, followed by 00Cr17Ni14Mo2Ti (316L) and HT250Ni2Cr. Increasing the rear shroud thickness would result in a notable reduction in its deformation. Evidently, the thicker the front and rear shrouds, the lower the shroud deformations. Among the three operating points, the displacement fields of the impeller were quite akin. An outward displacement growth was observed within the impeller hub to the outer diameter, thereby leaving both shrouds with a local maximum on the blade passage. Additionally, higher equivalent stress values were observed at the junction between the blade and the shroud. These results reveal the deformation and stress affecting the impeller, which then enables identification of and provides specific theoretical guidance for the optimization of the structural design of the pump.

Improvement of Anti-CD36 Antibody Detection via Monoclonal Antibody Immobilization of Platelet Antigens Assay by Using Selected Monoclonal Antibodies

Xu Xiuzhang,Chen Dawei,Ye Xin,Xia Wenjie,Shao Yuan,Deng Jing,Chen Yangkai,Ding Haoqiang,Liu Jing,Xu Yaori,Santoso Sentot,Fu Yongshui 대한진단검사의학회 2023 Annals of Laboratory Medicine Vol.43 No.1

Antibodies against human CD36 are responsible for several immune-mediated disorders. The detection of anti-CD36 antibodies using the standard monoclonal antibody (mAb) immobilization of platelet antigens (MAIPA) assay is hampered by a high frequency of false-negative results, most likely due to competitive inhibition of the mAb used as the capture antibody. We generated a panel of mouse mAbs against CD36 and seven hybridomas (GZ-3, GZ-13, GZ-70, GZ-143, GZ-413, GZ-507, and GZ-608), which were selected for MAIPA assays, as they reacted with mouse and human CD36. Fourteen anti-CD36 sera were assayed; all of which showed a positive reaction in a PakPlus (Immucor GTI Diagnostics, Inc., Waukesha, WI, USA) ELISA-based screening (optical density: 0.257–2.292). When the reference anti-CD36 mAb FA6-152 was used in the MAIPA assay, only 6/14 (42.9%) sera displayed a positive reaction. In contrast, anti-CD36 antibodies were detected in 13/14 (92.9%) sera when GZ-70 and GZ-608 mAbs were used. This significant improvement resulted in the identification of anti-CD36 antibodies by an antigen capture assay. Since patient’s platelets possibly carrying rare native antigens are used, this method will facilitate the identification of new platelet antibodies against CD36 that are involved in immune-mediated thrombocytopenia and other diseases, such as transfusion-related acute lung injury.