The Effect of Alkali Treatment on the Crystallinity, Thermal Stability, and Surface Roughness of Bamboo Fibers

Xiaoyang Fang,Jianuo Xu,Hongwu Guo,Yi Liu 한국섬유공학회 2023 Fibers and polymers Vol.24 No.2

The bamboo fibers were treated with sodium hydroxide (NaOH) to investigate the impacts of the NaOH concentration, reactiontemperature, and soaking time on the crystallinity, thermal stability, and surface roughness of bamboo fibers. The resultsrevealed that the NaOH concentration had a significant impact (0.01 < P < 0.05) on the crystallinity and thermal stability ofbamboo fibers, as well as an extremely significant impact (P < 0.01) on their surface roughness. It was found an extremelysignificant (P < 0.01) effect of the reaction temperature in the crystallinity and surface roughness of bamboo fibers but notin thermal stability. The soaking time significantly (P < 0.01) affected the surface roughness of bamboo fibers, whereas nosignificant effects were observed for the crystallinity and thermal stability. Compared with untreated bamboo fibers, thecrystallinity, thermal stability, and surface roughness of alkali-treated bamboo fibers generally increased.

중국 허난성 우양현 지아후 신석기 유적 뼈피리에 대한 복원 연구

팡샤오양(Fang, Xiaoyang),시아지(Xia, Ji),왕창수이(Wang, Changsui),판웨이빈(Fan, Weibin),구오웨이(Guo, Wei),권보나 (Kwon, Yeong) 한국음악도상학회 2023 뮤직인아트 Vol.2 No.-

The near-field acoustic levitation for spheres by transducer with concave spherical radiating surface

Jian-Fang Liu,Xu-Guang Sun,Xiaoyang Jiao,Hong-Xia Chen,Shun-Ming Hua,Hong-Chun Zhang 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.2

To levitate ICF target spheres in the near-field acoustic levitation, a transducer with concave spherical radiating surface and a near-field acoustic levitation system is established. The concave spherical radiating surface of the transducer is designed by the finite element parametric method. Then the levitation height and levitation perturbation of spheres with different mass and diameters in the near-field acoustic levitation system are tested and discussed in the driving voltage at 400V, 500V and 600V, respectively, when the levitation system is under the resonant frequency. Finally, based on the experimental results, the height formula of the near-field acoustic levitation for spheres is deduced by introducing a coupling coefficient.

Theoretical research and experimental study for a new measurement method of standing wave levitation force

Xinbo Li,Hai Jiang,Xiaoyang Jiao,Kai Zhang,Guojun Liu,Jian-Fang Liu 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.5

Based on the lever principle, a novel measurement method for the standing wave levitation force is investigated and the measurementdevice is developed. The relative levitation force was simulated by MATLAB software, from which the relative levitation force distributionand the curves of relative levitation force in vertical and horizontal directions were obtained. To verify the rationale of the measurementmethod, a series of experiments were carried out with the designed measurement device system. The levitation force distributionand the curves of levitation force in vertical and horizontal directions were also obtained from the experiment. Comparing the experimentalresults with the simulation, the levitation force distribution situation from the experimental results and the simulation is identical.

Bandwidth Scheduling for Big Data Transfer with Two Variable Node-Disjoint Paths

Aiqin Hou,Chase Qishi Wu,Liudong Zuo,Xiaoyang Zhang,Tao Wang,Dingyi Fang 한국통신학회 2020 Journal of communications and networks Vol.22 No.2

Many large-scale applications in broad science, engineering,and business domains are generating big data, which must betransferred to remote sites for various storage and analysis purposes. Bandwidth reservation services that discover feasible routingoptions over dedicated paths in high-performance networkshave proved to be effective for such big data transfer. In thispaper, we formulate a generic problem of bandwidth schedulingwith two variable node-disjoint paths (BS-2VNDP) by exploringthe flexibility and capacity of multiple data transfer paths. We furtherconsider two variable paths of either fixed or variable bandwidthwith negligible or non-negligible path switching delay, referredto as 2VPFB-0/1 and 2VPVB-0/1, respectively.We prove thatall of these four scheduling problems are NP-complete, and thenpropose a heuristic algorithm for each. For performance comparison,we also design several other heuristic algorithms based on agreedy strategy. These scheduling algorithms are implemented andtested in both simulated and real-life networks, and extensive resultsshow that the proposed heuristic algorithms significantly outperformother algorithms in comparison.

An improved resonantly driven piezoelectric gas pump

Yue Wu,Yong Liu,Jian-Fang Liu,Long Wang,Xiaoyang Jiao,Zhigang Yang 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.3

Piezoelectric pumps have the potential to be used in a variety of applications, such as in air circulation and compression. However, piezoelectric membrane pumps do not have enough driving capacity, and the heat induced during the direct contact between the driving part and the gas medium cannot be dissipated smoothly. When the gas is blocked, the piezoelectric vibrator generates heat quickly, which may eventually lead to damage. Resonantly driven piezoelectric stack pumps have high performance but no price advantage. In this situation, a novel, resonantly driven piezoelectric gas pump with annular bimorph as the driver is presented. In the study, the working principle of the novel pump was analyzed, the vibration mechanics model was deter-mined, and the displacement amplified theory was studied. The outcome indicates that the displacement amplification factor is related with the original displacement provided by the piezoelectric bimorph. In addition, the displacement amplification effect is related to the stiffness of the spring lamination, adjustment spring, and piezoelectric vibrator, as well as to the systematic damping factor and the driving frequency. The experimental prototypes of the proposed pump were designed, and the displacement amplification effect and gas output performance were measured. At 70 V of sinusoidal AC driving voltage, the improved pump amplified the piezoelectric vibrator displacement by 4.2 times, the maximum gas output flow rate reached 1685 ml/min, and the temperature of the bimorph remained normal after 2000 hours of operation when the gas medium was blocked.

Laboratory and field evaluation of the repellency of six preservatives to red imported fire ants (Hymenoptera: Formicidae)

Wenquan Qin,Hongpeng Xiong,YuzhenWen,XiujunWen,HuiWang,Yihan Fang,TaoMa,Zhaohui Sun,Xiaoyang Chen,Cai Wang 한국응용곤충학회 2017 Journal of Asia-Pacific Entomology Vol.20 No.2

Baiting is widely applied for the detection and control of the red imported fire ants, Solenopsis invicta Buren. Adding preservatives into baits would prevent microbial contamination during production and storage, and might extend period of bait attractiveness in the field. However, it is not known if preservatives are repellent to S. invicta. In the present study, potential effects of six commonly used preservatives (potassiumsorbate, sodium benzoate, sodium diacetate, sodium dehydroacetate, calcium propionate, and nisin) on the foraging behaviors of S. invicta foragers were evaluated under laboratory and field conditions. Four-choice tests (laboratory study) showed that the number of foraging ants on the preservative-treated (immersed in 2000-, 5000-, or 10,000-ppm solution for 30 min) and control (immersed in distilled water for 30 min) food was similar, with an exception of sodium dehydroacetate, which significantly decreased the number of foraging ants at the three tested concentrations. Interestingly, 46%, 58% and 71% of the food items treated with 2000-, 5000- and 10,000- ppm solutions of sodium dehydroacetate were buried with soil particles, respectively, whereas only 17% of the control food was similarly buried. Multiple-choice tests (field study) showed that food treated with the 5000- or 10,000-ppm solution of sodium dehydroacetate attracted significantly fewer S. invicta workers compared to other preservatives and the controls. Our study showed that the use of sodiumdehydroacetate should be avoided during the production of aqueous-based or liquid baits against S. invicta.