Dissimilatory Azoreduction of Orange I by a Newly Isolated Moderately Thermophilic Bacterium, Novibacillus thermophilus SG-1

Zhen Yu,Xuemei Zhou,Yueqiang Wang,Guiqin Yang,Shungui Zhou 한국생물공학회 2015 Biotechnology and Bioprocess Engineering Vol.20 No.6

Dye wastewater normally is discharged at high temperature, but thermophilic bacteria capable of decolorizing azo dyes have rarely been isolated. Here we report a newly isolated moderately thermophilic bacterium, Novibacillus thermophilus SG-1, which had a remarkable ability to decolorize the azo dye Orange I by utilizing a large variety of organic substrates as electron donors. When Orange I served as the sole electron acceptor, almost complete decolorization occurred at 50ºC and pH 8.0 with acetate as the electron donor after anaerobic incubation of strain SG-1 for 24 h. The decolorization process followed the pseudofirst- order kinetics. The complete reduction of 0.3 mM Orange I was accompanied by a stoichiometric consumption of 0.17 mM acetate over time. The measured molar ratio (1.76) of Orange I reduced to acetate oxidized was close to the theory value of 2.0, suggesting that most of the electrons released by acetate had been transported to Orange I. Simultaneously energy generated from the electron transfer process was used to support cell anaerobic growth, which meant that azoreduction by strain SG-1 is an azorespiration process. To our knowledge, this is the first report of a thermophilic bacterium capable of azorespiration, which increases the limited number of bacteria for treating hightemperature azo dye wastewater.

Mocklinter : Linting Mutual Exclusive Deadlocks with Lock Allocation Graphs

Zhen Yu,Xiaohong Su,Tiantian Wang,Peijun Ma 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.3

Deadlocks are serious runtime bugs and are difficult to expose, reproduce and diagnose. Once suffering from them, programs may be afflicted with increasing response time, decreasing throughputs, or even crashes. We present Mocklinter, a dynamic deadlock detection tool to capture a deadlock as soon as it happens and spit out enough information to support source-level debugging. Mocklinter tracks the synchronization state of the target program by dynamically constructing and maintaining a lock allocation graph. Mocklinter uses this graph to decide whether a deadlock is confronted or not. Mocklinter handles all types of pthread mutexes and can detect any number of deadlocks at a time. Each deadlock captured by Mocklinter can involve any number of threads. We implemented Mocklinter in Linux-3.2.0 and evaluated it with ten applications, including Dining-Philosophers, Sshfs, SQLite, OpenLDAP, MySQL and so on, whose sizes varies from 0.1K to 1021.0K in terms of LOC. The results demonstrate effectiveness against real or artificial deadlock bugs, while incurring modest performance overhead and scaling to more than one thousand of threads.

Simulation analysis and optimization design for wide band piezoelectric oscillator of energy harvesting device

Zhen Yu,Chen-yang Zhang,Si-yang Zhang 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.7

An L type broadband piezoelectric energy harvesting device was proposed in this paper, and the finite element model of L-type piezoelectric vibrator is established and simulated. It shows that the voltage corresponding to the first and third order resonant frequency is 0.06 V and 0.183 V, respectively, although higher than that of the ordinary piezoelectric vibrator, the voltage of the first mode and third mode for the piezoelectric vibrator is not close, which has little effect to broaden the bandwidth. Consequently, the simulation model for multi-cantilever piezoelectric vibrator was established, and its structural sizes were optimized, and it was obtained very close to first and third order resonant voltage, the bandwidth of the vibrator was broadened to 12.5 Hz. The multi-cantilever piezoelectric vibrator can be applied in a variety of devices for the collection of mechanical energy, and to provide a research foundation for the development of intelligent structures with self-sufficiency.

An Adaptive Fault-tolerant Robust Controller with Fault Diagnosis for Submarine’s Vertical Movement

Zhen Yu,Lijun Liu,Fei Wang 제어·로봇·시스템학회 2015 International Journal of Control, Automation, and Vol.13 No.6

In this paper, an integrated design of fault diagnosis and adaptive fault-tolerant robust control for a submarine with bow and stern plane faults is proposed. Considering the disturbance coming from waves when a submarine operates near sea surface, a simplified linear system of submarine’s vertical movement with both wave disturbance and bow and stern plane faults is presented. An unknown input observer is designed to decouple the wave disturbance and the bow and stern plane faults. Then a fault parameter tracking law is designed to estimate the bow and stern plane fault parameters without any prior fault information. Based on the estimated fault parameters, an adaptive robust fault-tolerant controller is designed. Simulation results show that the proposed control scheme has a satisfactory effect in the both pitch and depth control when the bow and stern planes suffer from unknown faults.

Array Organization and Data Management Exploration in Racetrack Memory

Zhenyu Sun,Xiuyuan Bi,Wenqing Wu,Sungjoo Yoo,Hai Helen Li IEEE 2016 IEEE Transactions on Computers Vol. No.

<P>As the descendant of spin-transfer random access memory (STT-RAM), racetrack memory technology saves data in magnetic domains along nanoscopic wires. Such a unique structure can achieve unprecedentedly high storage density meanwhile inheriting the promising features of STT-RAM, such as fast access speed, non-volatility, zero standby power, hardness to soft errors, and compatibility with CMOS technology. Moreover, the recent success in planar racetrack nanowire promised its fabrication feasibility and continuous scalability. In this paper, we investigate the design and optimization of racetrack memory as last-level cache by embracing design considerations across multiple abstraction layers, including the cell design, the array structure, the architecture organization, and the data management. The cross-layer optimization makes racetrack memory based last-level cache achieve 6.4 x reduction in area, 25 percent enhancement in system performance, and 62 percent saving in energy consumption, compared to STT-RAM cache design. Its benefit over SRAM technology is even more significant.</P>

Preparation and Photocatalytic Activity of ABi2O6/BiOCl (A = Mg, Sr, Ca) Heterojunction

Zhenyu Huang,Yan Wang,정동운 대한화학회 2018 Bulletin of the Korean Chemical Society Vol.39 No.9

MgBi2O6, CaBi2O6, and SrBi2O6 were successfully synthesized by a substitution reaction of NaBiO3 with MgCl2, CaCl2, and Sr(NO3)2, respectively. Then, ABi2O6/BiOCl (A = Mg, Ca, Sr) heterojunction compounds with different ABi2O6:BiOCl ratios were prepared by treating ABi2O6 with an appropriate amount of HCl. The color of the ABi2O6/BiOCl heterojunction was changed from dark to bright as the amount of BiOCl was increased. The absorbances of the ABi2O6/BiOCl heterojunctions in the visible range were decreased as the ratio of BiOCl became higher. The photocatalytic activities of the heterojunction samples were higher than that of sole ABi2O6 or BiOCl. The highest photocatalytic efficiency was achieved when the ABi2O6:BiOCl ratio was 15:85. The organic pollutant was decomposed completely within 1 h under visible light when the 15:85 catalyst was used. The reactive species in the photocatalytic reaction with the ABi2O6/BiOCl photocatalysts were ·O2- and h+ H+.

Three-point Bending Behavior and Energy Absorption Capacity of Composite Tube Reinforced by Gradient Braided Structure in Radial Direction

Zhenyu Wu,Yong Shen,Zhongxiang Pan,Xudong Hu 한국섬유공학회 2019 Fibers and polymers Vol.20 No.7

This study aims to investigate the radial gradient structural effect on energy absorption and failure behavior ofbraided composite tubes. Two-layer tubular braided fabrics were fabricated using over-braiding technology with three typesof radial gradient configurations in terms of uninform, descending and ascending pattern. The structure of surface layertouching with indenter roll was found to have a significant role on the bending behavior and failure mode. The compositetube possessing the small angle surface layer tends to fail in top-surface mode characterized by compression damage incontact area between indenter roll and tube. With the increasing of the braiding angle in surface layer, the bottom-surfacefailure mode characterized by penetrating crack in circumferential direction was observed, which accompanies abruptlyloading drop and loss of energy absorption capacity. In addition, the tube in descending gradient pattern contributes to higherflexural modulus and peak load due to high fiber volume fraction, while keeps top-surface failure mode because of loadspreading ability provided by surface layer with small braiding angle. The results show that a proper selection of stackingsequence and braiding angle in multi-layer braided tube is capable of effectively enhancing the energy absorption of tubalstructures under bending load.

Design for Forecasting System of Tobacco Sales Based on Time Series

Zhenyu Yang 보안공학연구지원센터 2016 International Journal of u- and e- Service, Scienc Vol.9 No.8

The sales forecast in the tobacco sales management plays a great role in the production and operation activities of an enterprise as a bridge between the production activity and the economic benefit. Forecasting system based on time series is put forward in accordance with the characteristics of tobacco sales by knowing about market supply and demand as well as development tendency at home and abroad through the sales forecast, with the help of studies on the sales forecasting technology. Time series is a sequence of random variables in chronological order and the time series analysis technique includes the moving average forecasting, exponential smoothing and regression analysis. According to the characteristics of tobacco sales data, the moving average forecasting model, exponential smoothing model and regression analysis model are established. Through programming, a forecasting system of tobacco sales is set up, which is used in combination with examples to simulate the forecasting model, and then model tests are conducted on the simulation results to get the appropriate model, which is used for sales forecast. The establishment of the system has an important influence on the management of tobacco companies. According to the forecast of tobacco sales, they will know the sales of the next period, so that they can take effective sales management strategies to improve the accuracy and efficiency of the decisions on the company's production and operation.

Hair follicle development and related gene and protein expression of skins in Rex rabbits during the first 8 weeks of life

Zhenyu Wu,Liangzhan Sun,Gongyan Liu,Hongli Liu,Hanzhong Liu,Zhiju Yu,Shuang Xu,Fuchang Li,Yingbe Qin 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.4

Objective: We aimed to observe hair follicle (HF) development in the dorsal skin and elucidate the expression patterns of genes and proteins related to skin and HF development in Rex rabbits from birth to 8 weeks of age. Methods: Whole-skin samples were obtained from the backs of Rex rabbits at 0, 2, 4, 6, and 8 weeks of age, the morphological development of primary and secondary HFs was observed, and the gene transcript levels of insulin-like growth factor-I (IGF-I), epidermal growth factor (EGF), bone morphogenetic protein 2 (BMP2), transforming growth factor β-1, 2, and 3 (TGFβ-1, TGFβ-2, and TGFβ-3) were examined using quantitative real-time polymerase chain reaction (PCR). Additionally, Wnt family member 10b (Wnt10b) and β-Catenin gene and protein expression were examined by quantitative real-time PCR and western blot, respectively. Results: The results showed significant changes in the differentiation of primary and secondary HFs in Rex rabbits during their first 8 weeks of life. The IGF-I, EGF, TGFβ-2, and TGFβ-3 transcript levels in the rabbits were significantly lower at 2 weeks of age than at birth and gradually increased thereafter, while the BMP2 and TGFβ-1 transcript levels at 2 weeks of age were significantly higher than those at birth and gradually decreased thereafter. β-Catenin gene expression was also significantly affected by age, while the Wnt10b transcript level was not. However, the Wnt10b and β-catenin protein expression levels were the lowest at 2 and 4 weeks of age. Conclusion: Our data showed that a series of changes in HFs in dorsal skin occurred during the first 8 weeks. Many genes, such as IGF-I, EGF, BMP2, TGFβ-1, TGFβ-2, TGFβ-3, and β-Catenin, participated in this process, and the related proteins Wnt10b and β-Catenin in skin were also affected by age.

연구원 활동 : 발표논문요약 ; < 전파공학분야 >

(Zhenyu Zhou),(Costas E . Synolakis),(Richard M . Leahy),(Samuel M . Song) 고려대학교 공학기술연구소 1996 생산기술연구소보 Vol.3 No.-