Identification of Dominant Microbial Community and Diversity in Continuously Cropped Pepper Fields

Hui Wang,Li Liu,Shuyi Yu,Tianshu Guan,Baihong Li,Qi Wang,Changyuan Liu 한국원예학회 2021 원예과학기술지 Vol.39 No.4

Pepper blight is the most significant soil-borne disease affecting the continuous cropping of peppers. To identify the effect of Phytophthora capsici infection on microbial flora, we isolated and counted the microorganisms collected from the rhizosphere soil of P. capsici-affected farms that continuously cropped pepper for 3, 6, and 9 years in Liaoning Province, China. The colony and cell morphology, physiological and biochemical characteristics, and 16S rDNA sequence of bacteria and actinomycetes were documented. In addition, colony and microscopic morphology of fungi and the rDNA-ITS sequence were analysed for classification. We observed that healthy and diseased peppers had the largest number of bacteria in the rhizosphere followed by actinomycetes and fungi. After infection, the number of bacteria and actinomycetes decreased with a corresponding increase in the number of fungi, leading to a reduction in the ratio of bacteria/fungi to actinomycetes/fungi. We identified 15 dominant bacterial strains, of which Bacillus represented the most abundant genus consisting of 7 strains followed by Flavobacterium and Staphylococcus. Furthermore, 15 of the 17 actinomycetes strains belonged to the genus Streptomyces. Among the six fungal strains, we found P. infestans, Fusarium, and Penicillium consisting of two strains each. This study elucidated the impact of pathogenic P. capsici on the composition of soil microbes over time and characterized several cultivatable dominant bacterial groups, which can provide a basis for practical intervention strategies to improve soil conditions for continuous cropping.

A Novel Zero-Crossing Compensation Scheme for Fixed Off-Time Controlled High Power Factor AC-DC LED Drivers

Changyuan Chang,Hailong Sun,Wenwen Zhu,Yao Chen,Chenhao Wang 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.5

A fixed off-time controlled high power factor ac-dc LED driver is proposed in this paper, which employs a novel zero-crossing-compensation (ZCC) circuit based on a fixed off-time controlled scheme. Due to the parasitic parameters of the system, the practical waveforms have a dead region. By detecting the zero-crossing boundary, the proposed ZCC circuit compensates the control signal VCOMP within the dead region, and is invalid above this region. With further optimization of the parameters KR and Kτ of the ZCC circuit, the dead zone can be eliminated and lower THD is achieved. Finally, the chip is implemented in HHNEC 0.5㎛ 5V/40V HVCMOS process, and a prototype circuit, delivering 7~12W of power to several 3-W LED loads, is tested under AC input voltage ranging from 85V to 265V. The test results indicate that the average total harmonic distortion (THD) of the entire system is approximately 10%, with a minimum of 5.5%, and that the power factor is above 0.955, with a maximum of 0.999.

A Novel Zero-Crossing Compensation Scheme for Fixed Off-Time Controlled High Power Factor AC-DC LED Drivers

Chang, Changyuan,Sun, Hailong,Zhu, Wenwen,Chen, Yao,Wang, Chenhao The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.5

A fixed off-time controlled high power factor ac-dc LED driver is proposed in this paper, which employs a novel zero-crossing-compensation (ZCC) circuit based on a fixed off-time controlled scheme. Due to the parasitic parameters of the system, the practical waveforms have a dead region. By detecting the zero-crossing boundary, the proposed ZCC circuit compensates the control signal VCOMP within the dead region, and is invalid above this region. With further optimization of the parameters KR and Kτ of the ZCC circuit, the dead zone can be eliminated and lower THD is achieved. Finally, the chip is implemented in HHNEC 0.5μm 5V/40V HVCMOS process, and a prototype circuit, delivering 7~12W of power to several 3-W LED loads, is tested under AC input voltage ranging from 85V to 265V. The test results indicate that the average total harmonic distortion (THD) of the entire system is approximately 10%, with a minimum of 5.5%, and that the power factor is above 0.955, with a maximum of 0.999.

Design of efficient optimized wireless power transfer system

Wu, Qian,Wang, Lei,Ju, Dongqian,Chen, Chang,Chang, Changyuan The Korean Institute of Power Electronics 2020 JOURNAL OF POWER ELECTRONICS Vol.20 No.5

To balance the output stability and maximum efficiency of a system, an efficiency optimization method based on adaptive frequency control is proposed. In this paper, load transmission is carried out using a DC-DC converter at the receiving end. When the load changes, controlling the rectified output voltage is carried out to realize the maximum efficiency point tracking. Meanwhile, the duty cycle of the rear stage DC-DC converter is changed to keep the output voltage constant. The sampled rectified voltage is compared with the estimated value and the resulting error data are sent to the system transmitter through ASK modulation wireless communication. Then the transmitter demodulation communication information through PID algorithm control is used to achieve the frequency of the adaptive adjustment. The feasibility of the proposed method has been verified by the simulation and experimental results. When the output voltage is 5 V, the constant voltage accuracy is within±1%, the maximum efficiency is up to 79.2%, and the dynamic response time is only 160 ms.

Robust Fractional Embedded Cubature Kalman Filter for Fractional Nonlinear Stochastic System

Jing Mu,Changyuan Wang,Wuqi Gao,Feng Tian,Jianlian Cheng 제어·로봇·시스템학회 2022 International Journal of Control, Automation, and Vol.20 No.11

In this study, the fractional embedded cubature Kalman filter (FECKF) and robust fractional embedded cubature Kalman filter (RoFECKF) are proposed to design the estimate the states for fractional-order nonlinear discrete systems with Gaussian and non-Gaussian measurement noise, respectively. We develop FECKF algorith by extending embedded cubature Kalman filter to fractional nonlinear stochastic system with Gaussian noise. Meanwhile, RoFECKF is put forward to increase the estimation robustness under noisy measurements by applying the Huber method to FECKF. Simulation results on adaptive system identification and re-entry target tracking system demonstrate the effectiveness and robustness of the proposed approach.

Additively manufactured nano-mechanical energy harvesting systems: advancements, potential applications, challenges and future perspectives

Ahmed Ammar,Azam Ali,Wang Yanen,Zhang Zutao,Li Ning,Jia Changyuan,Mushtaq Ray Tahir,Rehman Mudassar,Gueye Thierno,Shahid Muhammad Bilal,Basit Ali Wajid 나노기술연구협의회 2021 Nano Convergence Vol.8 No.37

Additively manufactured nano-MEH systems are widely used to harvest energy from renewable and sustainable energy sources such as wind, ocean, sunlight, raindrops, and ambient vibrations. A comprehensive study focusing on in-depth technology evolution, applications, problems, and future trends of specifically 3D printed nano-MEH systems with an energy point of view is rarely conducted. Therefore, this paper looks into the state-of-the-art technologies, energy harvesting sources/methods, performance, implementations, emerging applications, potential challenges, and future perspectives of additively manufactured nano-mechanical energy harvesting (3DP-NMEH) systems. The prevailing challenges concerning renewable energy harvesting capacities, optimal energy scavenging, power management, material functionalization, sustainable prototyping strategies, new materials, commercialization, and hybridization are discussed. A novel solution is proposed for renewable energy generation and medicinal purposes based on the sustainable utilization of recyclable municipal and medical waste generated during the COVID-19 pandemic. Finally, recommendations for future research are presented concerning the cutting-edge issues hurdling the optimal exploitation of renewable energy resources through NMEHs. China and the USA are the most significant leading forces in enhancing 3DP-NMEH technology, with more than 75% contributions collectively. The reported output energy capacities of additively manufactured nano-MEH systems were 0.5–32 mW, 0.0002–45.6 mW, and 0.3–4.67 mW for electromagnetic, piezoelectric, and triboelectric nanogenerators, respectively. The optimal strategies and techniques to enhance these energy capacities are compiled in this paper. Graphical Abstract

PSR CC/CV AC-DC converter with an adaptive high-precision closed-loop constant current control scheme

Gu, Yang,Ju, Dongqian,Wang, Lei,Ren, Jie,Chang, Changyuan The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.7

A primary-side regulation (PSR) constant current (CC) output and constant voltage (CV) output AC-DC converter is proposed and an adaptive high-precision closed-loop constant current control scheme is put forward in this paper. In the CC mode, the converter adopts the closed-loop control strategy to realize that the switching period adaptively converges to twice the demagnetization time, which realizes the CC output. In addition, exactly detecting the demagnetization time is a prerequisite for obtaining a high-precision output current. Therefore, a demagnetization time detection circuit is designed to provide accurate and reliable demagnetization information. The control IC was fabricated with the Nuvoton 0.5um BCD process, and a 5 V/2 A prototype circuit was implemented to verify its performance. Experimental results show that the CC deviation is within ± 1.4%, which is lower than the target value of ± 2.0%. Under different loads and AC inputs, the conversion efficiency in the CC mode varies between 76.3% and 80.7%.

Phenolic features and anthocyanin profiles in winemaking pomace and fresh berries of grapes with different pedigrees

Lei Zhu,Xin Wu,Xixi Hu,Xinyue Li,Shanshan Lv,Chuan Zhan,Yunhua Chen,Changyuan Wang,Jingyu Xu 한국식품과학회 2023 Food Science and Biotechnology Vol.32 No.2

The total contents and antioxidant activities of phenolic compounds as well as anthocyanin profiles were analyzed and compared in fresh berries and fermented pomace of three grape cultivars with different pedigrees. The phenolic contents and antioxidant activities decreased significantly in skins (p < 0.05), while relatively large amounts of them were retained in seeds after fermentative maceration. Fermentative maceration also had a significant impact on the anthocyanin compositions. The proportions of anthocyanins with more stable structures, such as malvidin derivatives, methylated, diglucosides and nonacylated anthocyanins, increased significantly in the pomace skins (p < 0.05). There were obvious differences in phenolic features and anthocyanin profiles among the three cultivars. ‘NW196’, a wine hybrid of Vitis vinifera and V. quinquangularis, was characterized by the highest total anthocyanin contents and degree of diglucosylation. The results obtained in this study could contribute to the primary data for the development and utilization of winemaking pomace, especially from local non-Vitis vinifera grapes.

중국 흑룡강성 간흡충증 관리사업(2001-2004)

지주오,이즈민,왕수유,위안런,거타오,위안샹,추이창위안,거홍안,평정,슈롱치,홍성태,최민호,조승열,최동일,홍광선,임한종,이순형,Ji, Zhuo,Li, Zhimin,Wang, Shuyu,Yuan, Ren,Ge, Tao,Yuan, Shang,Cui, Changyuan,Ge, Hongan,Feng, Zheng,Xu, Longqi,Hong, Sung-Tae,Choi, 한국건강관리협회 2005 한국건강관리협회지 Vol.3 No.1

The present pilot project was executed to recommend a strategy of clonorchiasis control in China. The pilot area of this project was Zhaoyuan, Hailin, and Ningan, Heiloagjiang province. A baseline survey subjecting 4,865 residents in Heilongjiang confirmed Zhaoyuan asa high endemic area and Hailin and Ningan as moderate endemic areas. Six different control strategies were implemented in Zhaoyuan, two were in Hailin, and one was in Ningan. Including the baseline survey and project programs from 2000 to 2004, total 63,274subject-times were examined of their feces for Clonorchiseggs, 26,680 were treated, 10,082 were screened by ELISA, and 6,130 subjects were examined of their liver by sonography. The egg Positive rates in 6 villages of Zhaoyuan were as high as 44.8% 70,0%. Following the protocolof each strategy, the subjected residents were examined of their feces and treated with 25 mg/kg praziquantel, 3 times. Except the control group, all of the villages showed 72.8% to 92.0% reduction of their original egg Positive rates at Zhaoyuan. Mass treatments of all subjected residents in 2001 and 2003 reduced the egg rate from 68.8% to18.7% and 4 annual mass treatments reduced the rate from 44.8% in 2001 to 8.7% in 2004.Selective annual treatments of egg positive subjects reduced the egg rates from 50.8% in2001 to 13.8% in 2004 or from 70.0% in 2001 to 11.6% in 2004, and two treatments in a year reduced the rate from 57.6% in 2001 to 4.6% in 2004. According to repeated treatments, EPG counts decreased remarkably. In moderate endemic areas, the original egg rates were 22.6% and 28.3% in 2001 but were 1.7% and 1.1% after 2 or 3 selective treatments. The present findings of the chemotherapeutic control of clonorchiasis prove that repeated medication is important. The reduction is directly correlated with dose of praziquantel but not with mass or selective treatments. Chemotherapeutic control of reservoirhosts has little effect on reinfection of clonorchiasis because the field along the Songhua-jiang is too wide to be impacted. ELISA confirmed many serologically positive cases to Clonorchisantigen but only a few cases were positive to other antigens (Paragonimus, cysticercus, sparganum). The abdominal soaography visualized intrahepatic bile duct dilatation and periductal echo in 2,002 of 6,070 examined subjects. In addition to these examinations and treatment, health education supplemented tㅗe control activities. The present findings prove clonorchiasis is very widely prevalent and heavily endemic along the rivers in Heiloagjiang. The results suggest that group chemotherapy with praziquantel is effective to reduce endemicity of clonorchiasis. Mass treatment without individual fecal examination is recommended in heavy endemic areas where the egg rate is over 40% while one selective treatment is effective enough in moderate endemic areas.

Small-Signal Modeling and Control of Three-Phase Bridge Boost Rectifiers under Non-Sinusoidal Conditions

Chang, Yuan,Jinjun, Liu,Xiaoyu, Wang,Zhaoan, Wang The Korean Institute of Power Electronics 2009 JOURNAL OF POWER ELECTRONICS Vol.9 No.5

This paper proposes a systematic approach to the modeling of the small-signal characteristics of three-phase bridge boost rectifiers under non-sinusoidal conditions. The main obstacle to the conventional synchronous d-q frame modeling approach is that it is unable to identify a steady-state under non-sinusoidal conditions. However, for most applications under non-sinusoidal conditions, the current loops of boost rectifiers are designed to have a bandwidth that is much higher than typical harmonics frequencies in order to achieve good current control for these harmonic components. Therefore a quasi-static method is applied to the proposed modeling approach. The converter small-signal characteristics developed from conventional synchronous frame modeling under different operating points are investigated and a worst case point is then located for the current loop design. Both qualitative and quantitative analyses are presented. It is observed that operating points influence the converter low frequency characteristics but hardly affect the dominant poles. The relationship between power stage parameters, system poles and zeroes is also presented which offers good support for the system design. Both the simulation and experimental results verified the analysis and proposed modeling approach. Finally, the practical case of a parallel active power filter is studied to present the modeling approach and the resultant regulator design procedure. The system performance further verifies the whole analysis.