Chemical kinetics of bean straw biofuel pyrolysis using maximum volatile release method

Wei Chen,Kalyan Annamalai,Jiafeng Sun,Yuming Chen 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.8

Maximum volatile release (MVR) methods, including single point (MVR-S) and multiple (MVR-M) points, are proposed to extract the kinetics used to predict the fuel bean straw pyrolysis process. The simulation results were compared to those of the distributed activation energy model (DAEM). For the TGA (thermogravimetric analysis) experiments, fuels were heated from ambient temperature to 1,173 K at the heating rates of 10, 20, 40, 60, 80 K min−1, and the corresponding maximum volatile release points were obtained. For the MVR-S method, both the activation energy (E) and pre-exponential factor (B) increased with increasing heating rates. For the pyrolysis weight loss process, the DAEM showed best agreement with the experimental data, followed by the MVR-M, and then the MVR-S method. However, for weight loss rate prediction, MVR-S method had the best match with the experimental data, whereas the DAEM and MVR-M method generated more errors.

GENERALIZED YANG'S CONJECTURE ON THE PERIODICITY OF ENTIRE FUNCTIONS

Liu, Kai,Wei, Yuming,Yu, Peiyong Korean Mathematical Society 2020 대한수학회보 Vol.57 No.5

On the periodicity of transcendental entire functions, Yang's Conjecture is proposed in [6, 13]. In the paper, we mainly consider and obtain partial results on a general version of Yang's Conjecture, namely, if f(z)ⁿf^(k)(z) is a periodic function, then f(z) is also a periodic function. We also prove that if f(z)ⁿ+f^(k)(z) is a periodic function with additional assumptions, then f(z) is also a periodic function, where n, k are positive integers.

Genistein activates endothelial nitric oxide synthase in broiler pulmonary arterial endothelial cells by an Akt-dependent mechanism

Ying Yang,Wei Nie,Jianmin Yuan,Bingkun Zhang,Zhong Wang,Zhenlong Wu,Yuming Guo 생화학분자생물학회 2010 Experimental and molecular medicine Vol.42 No.11

Deregulation of endothelial nitric oxide synthase (eNOS)plays an important role in the development of multiple cardiovascular diseases. Our recent study demonstrated that genistein supplementation attenuates pulmonary arterial hypertension in broilers by restoration of endothelial function. In this study, we investigated the molecular mechanism by using broiler pulmonary arterial endothelial cells (PAECs). Our results showed that genistein stimulated a rapid phosphorylation of eNOS at Ser1179 which was associated with activation of eNOS/NO axis. Further study indicated that the activation of eNOS was not mediated through estrogen receptors or tyrosine kinase inhibition, but via a phosphatidylinositol 3-kinase (PI3K)/Akt-dependent signaling pathway, as the eNOS activity and related NO release were largely abolished by pharmacological inhibitors of PI3K or Akt. Thus, our findings revealed a critical function of Akt in mediating genistein-stimulated eNOS activity in PAECs, partially accounting for the beneficial effects of genistein on the development of cardiovascular diseases observed in animal models.

Suppression of stray electrons in the negative ion accelerator of CRAFT NNBI test facility

Yang Yuwen,Wei Jianglong,Xie Junwei,Gu Yuming,Xie Yahong,Hu Chundong 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.3

Comprehensive Research Facility for Fusion Technology (CRAFT) is an integration of different demonstrating or testing facilities, which aim to develop the critical technology or composition system towards the fusion reactor. Due to the importance and challenge of the negative ion based neutral beam injection (NNBI), a NNBI test facility is included in the framework of CRAFT. The initial object of CRAFT NNBI test facility is to obtain a H0 beam power of 2 MW at the energy of 200e400 keV for the pulse duration of 100 s. Inside the negative ion accelerator of NNBI system, the interactions of the negative ions with the background gas and electrodes can generate abundant stray electrons. The stray electrons can be further accelerated and dumped on the electrodes or eject from the accelerator. The stray electrons, including the ejecting electrons, cause the unwanted particle and heat flux onto the electrodes and the inner components of beamline (especially the temperature sensitive cryopump). The suppression of the stray electrons from the CRAFT accelerator is carried out via a series of design and simulation works. The paper focuses the influence of different magnetic field configurations on the stray electrons and the character of the ejecting electrons.

Lysine Requirement of Male White Pekin Ducklings from Seven to Twenty-one Days of Age

Xie, Ming,Guo, Yuming,Zhang, Ting,Hou, Shuisheng,Huang, Wei Asian Australasian Association of Animal Productio 2009 Animal Bioscience Vol.22 No.10

A dose-response experiment with five lysine levels (0.65, 0.80, 0.95, 1.10, and 1.25%) was conducted to evaluate the lysine requirement of male White Pekin ducklings from 7 to 21 days of age. Two hundred and eighty, 7-day-old, male White Pekin ducklings were allocated to 5 experimental treatments, each containing 8 replicate pens with 7 birds per pen. Feed and water were provided ad libitum from 7 to 21 days of age. At 21 days of age, weight gain, feed intake, feed/gain, breast meat weight, and breast meat yield relative to body weight of ducklings from each pen were all measured. As dietary lysine level increased, weight gain, feed intake, feed/gain, breast meat weight, and breast meat yield of ducklings were all improved significantly (p<0.05). According to broken-line regression analysis, the lysine requirement of male White Pekin ducklings from 7 to 21 days of age for weight gain, feed/gain, breast meat weight, and breast meat yield was 0.84, 0.90, 0.97, and 0.98%, respectively. Considering that Pekin duck production is directed to meat production, the lysine requirement of male starter Pekin ducklings during this period is suggested to be 0.98%.

In-plane Dielectric Properties of Epitaxial Orthorhombic HoMnO3 Films Grown on LaAlO3 Substrates

Weitian Wang,Ping Gao,Wei Zhang,Yuming Sun 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.63 No.9

Orthorhombic HoMnO₃ thin films were grown epitaxially on LaAlO₃ (001) substrates by using apulsed laser deposition technique. The films showed perfectly orthorhombic crystallization and werewell-aligned with the substrates. The in-plane dielectric constant and the dielectric loss of HoMnO₃films were measured as functions of temperature (80 ~ 300 K) and frequency (120 ~ 100 kHz) byusing interdigital surface electrodes. Two thermally-activated dielectric relaxations were found, andthe respective peaks shifted to higher temperatures as the measuring frequency was increased. Thein-plane dielectric properties of epitaxial orthorhombic HoMnO₃ films were considered to have auniversal dielectric response behavior, and the dipoar effects and the hopping conductivity inducedby the charge carriers were used to explain the results. The dielectric properties at low temperatures,which showed the multiferroicity, of the orthorhombic HoMnO₃ films are discussed.

An Improved Model Predictive Torque Control Strategy of a Shearer Semi-direct Permanent Magnet Synchronous Motor Based on Duty Cycle

Du Wenlong,Li Wei,Lu En,Sheng Lianchao,Chen Yuming,Jiang Song 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.5

In order to improve the stability of low-speed and high-torque permanent magnet synchronous motor control in the shearer semi-direct cutting system under large load fl uctuation and strong impact conditions, an improved model predictive torque control strategy based on duty cycle is proposed which can eff ectively reduce the fl ux and torque ripples and improve steadystate control performance. This method combines the separate process of the voltage vector selection and the duty cycle calculation through the predictive model combined with duty cycle. Then, the optimal voltage vector and its duration is selected simultaneously based on minimizing the cost function. In addition, in order to mitigates the computational burden of the proposed method, the voltage vectors in the fi nite control set is pre-selected using hysteresis comparator according to the motor operating status. Furthermore, the duty cycle pulse width modulation is introduced to obtain a fi xed switching frequency of the inverter. The results of simulation experiments confi rm that the proposed strategy can signifi cantly reduce the fl ux and torque ripples and improve the steady state performance while maintaining fast dynamic response.

Genistein activates endothelial nitric oxide synthase in broiler pulmonary arterial endothelial cells by an Akt-dependent mechanism

Yang, Ying,Nie, Wei,Yuan, Jianmin,Zhang, Bingkun,Wang, Zhong,Wu, Zhenlong,Guo, Yuming Korean Society for Biochemistry and Molecular Bion 2010 Experimental and molecular medicine Vol.42 No.11

Deregulation of endothelial nitric oxide synthase (eNOS) plays an important role in the development of multiple cardiovascular diseases. Our recent study demonstrated that genistein supplementation attenuates pulmonary arterial hypertension in broilers by restoration of endothelial function. In this study, we investigated the molecular mechanism by using broiler pulmonary arterial endothelial cells (PAECs). Our results showed that genistein stimulated a rapid phosphorylation of eNOS at $Ser^{1179}$ which was associated with activation of eNOS/NO axis. Further study indicated that the activation of eNOS was not mediated through estrogen receptors or tyrosine kinase inhibition, but via a phosphatidylinositol 3-kinase (PI3K)/Akt-dependent signaling pathway, as the eNOS activity and related NO release were largely abolished by pharmacological inhibitors of PI3K or Akt. Thus, our findings revealed a critical function of Akt in mediating genistein-stimulated eNOS activity in PAECs, partially accounting for the beneficial effects of genistein on the development of cardiovascular diseases observed in animal models.

Design for Hybrid Circular Bragg Gratings for a Highly Efficient Quantum-Dot Single-Photon Source

Beimeng Yao,Rongbin Su,Yuming Wei,Zhuojun Liu,Tianming Zhao,Jin Liu 한국물리학회 2018 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.73 No.10

We present a design for hybrid circular Bragg gratings (hCBGs) for eciently extracting singlephotons emitted by InAs quantum dots (QDs) embedded in GaAs. Finite-difference time-domain simulations show that a very high photon collection eciency (PCE) up to 96% over a 50 nm bandwidth and pronounced Purcell factors up to 19 at cavity resonance are obtained. We also systematically investigate the geometry parameters, including the SiO2 thickness, grating period, gap width and the central disk radius, to improve the device performances. Finally, the PCEs and the Purcell factors of QDs located at different positions of the hCBG are studied, and the results show great robustness against uncertainties in the location of the QD.

Evaluating and predicting net energy value of wheat and wheat bran for broiler chickens

Ning Ran,Cheng Zichen,Liu Xingbo,Ban Zhibin,Guo Yuming,Nie Wei 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.11

Objective: It is crucial to accurately determine the net energy (NE) values of feed ingredients because the NE system is expected to be applied to the formulation of broilers feed. The NE values of 5 wheat and 5 wheat brans were determined in 12-to 14-day old Arbor Acres (AA) broilers with substitution method and indirect calorimetry method. Methods: A total of 12 diets, including 2 reference diets (REF) and 10 test diets (5 wheat diets and 5 wheat bran diets) containing 30% of test ingredients, were randomly fed to 864 male AA birds with 6 replicates of 12 birds per treatment. These birds were used to determine metabolizable energy (ME) (8 birds per replicate) in the chicken house and NE (4 birds per replicate) in the chamber respectively at the same time. After a 4-d dietary and environment adaptation period, growth performance, energy values, energy balance and energy utilization were measured during the following 3 d. Multiple linear regression analyses were further performed to generate prediction equations for NE values based on the chemical components and ME values. The NE prediction equation were also validated on another wheat diet and another wheat bran diet with high correlation (r = 0.98, r = 0.75). Results: The NE values of 5 wheat and 5 wheat bran samples are 9.34, 10.02, 10.27, 11.33, and 10.49 MJ/kg, and 5.37, 5.17, 4.87, 5.06, and 4.88 MJ/kg DM, respectively. The equation with the best fit were NE = 1.968AME–0.411×ADF–14.227 (for wheat) and NE = –0.382×CF –0.362×CP–0.244×ADF+20.870 (for wheat bran). Conclusion: The mean NE values of wheat and wheat bran are 10.29 and 5.07 MJ/kg DM in AA broilers. The NE values of ingredients could be predicted by their chemical composition and energy value with good fitness. Objective: It is crucial to accurately determine the net energy (NE) values of feed ingredients because the NE system is expected to be applied to the formulation of broilers feed. The NE values of 5 wheat and 5 wheat brans were determined in 12-to 14-day old Arbor Acres (AA) broilers with substitution method and indirect calorimetry method.Methods: A total of 12 diets, including 2 reference diets (REF) and 10 test diets (5 wheat diets and 5 wheat bran diets) containing 30% of test ingredients, were randomly fed to 864 male AA birds with 6 replicates of 12 birds per treatment. These birds were used to determine metabolizable energy (ME) (8 birds per replicate) in the chicken house and NE (4 birds per replicate) in the chamber respectively at the same time. After a 4-d dietary and environment adaptation period, growth performance, energy values, energy balance and energy utilization were measured during the following 3 d. Multiple linear regression analyses were further performed to generate prediction equations for NE values based on the chemical components and ME values. The NE prediction equation were also validated on another wheat diet and another wheat bran diet with high correlation (r = 0.98, r = 0.75).Results: The NE values of 5 wheat and 5 wheat bran samples are 9.34, 10.02, 10.27, 11.33, and 10.49 MJ/kg, and 5.37, 5.17, 4.87, 5.06, and 4.88 MJ/kg DM, respectively. The equation with the best fit were NE = 1.968AME–0.411×ADF–14.227 (for wheat) and NE = –0.382×CF–0.362×CP–0.244×ADF+20.870 (for wheat bran).Conclusion: The mean NE values of wheat and wheat bran are 10.29 and 5.07 MJ/kg DM in AA broilers. The NE values of ingredients could be predicted by their chemical composition and energy value with good fitness.