http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
오늘 본 자료
Li Xian-Wen,Su Xing-Kang,Gu Long,Wang Xiang-Yang,Fan Da-Jun 한국원자력학회 2023 Nuclear Engineering and Technology Vol.55 No.5
Conjugate heat transfer between liquid metal and solid is a common phenomenon in a liquid-metalcooled fast reactor's fuel assembly and heat exchanger, dramatically affecting the reactor’s safety and economy. Therefore, comprehensively studying the sophisticated conjugate heat transfer in a liquidmetal-cooled fast reactor is profound. However, it has been evidenced that the traditional Simple Gradient Diffusion Hypothesis (SGDH), assuming a constant turbulent Prandtl number (Prt, usually 0.85 - 1.0), is inappropriate in the Computational Fluid Dynamics (CFD) simulations of liquid metal. In recent decades, numerous studies have been performed on the four-equation model, which is expected to improve the precision of liquid metal’s CFD simulations but has not been introduced into the conjugate heat transfer calculation between liquid metal and solid. Consequently, a four-equation model, consisting of the Abe k ε turbulence model and the Manservisi kq εq heat transfer model, is applied to study the conjugate heat transfer concerning liquid metal in the present work. To verify the numerical validity of the four-equation model used in the conjugate heat transfer simulations, we reproduce Johnson’s experiments of the liquid lead-bismuth-cooled turbulent pipe flow using the four-equation model and the traditional SGDH model. The simulation results obtained with different models are compared with the available experimental data, revealing that the relative errors of the local Nusselt number and mean heat transfer coefficient obtained with the four-equation model are considerably reduced compared with the SGDH model. Then, the thermal-hydraulic characteristics of liquid metal turbulent pipe flow obtained with the four-equation model are analyzed. Moreover, the impact of the turbulence model used in the four-equation model on overall simulation performance is investigated. At last, the effectiveness of the four-equation model in the CFD simulations of liquid sodium conjugate heat transfer is assessed. This paper mainly proves that it is feasible to use the four-equation model in the study of liquid metal conjugate heat transfer and provides a reference for the research of conjugate heat transfer in a liquidmetal-cooled fast reactor
Lee, Bo-Ah,Kang, Choong-Hee,Vang, Mong-Sook,Jung, Young-Suk,Piao, Xing Hui,Kim, Ok-Su,Chung, Hyun-Ju,Kim, Young-Joon Korean Academy of Periodontology 2012 Journal of Periodontal & Implant Science Vol.42 No.6
Purpose: The aim of the present study was to evaluate the biological response of alkali- and heat-treated titanium-8tantalum-3niobium surfaces by cell proliferation and alkaline phosphatase (ALP) activity analysis. Methods: Commercial pure titanium (group cp-Ti) and alkali- and heat-treated titanium-8tantalum-3niobium (group AHT) disks were prepared. The surface properties were evaluated using scanning electron microscopy, energy dispersed spectroscopy and X-ray photoelectron spectroscopy (XPS). The surface roughness was evaluated by atomic force microscopy and a profilometer. The contact angle and surface energy were also analyzed. The biological response of fetal rat calvarial cells on group AHT was assessed by cell proliferation and ALP activity. Results: Group AHT showed a flake-like morphology microprofile and dense structure. XPS analysis of group AHT showed an increased amount of oxygen in the basic hydroxyl residue of titanium hydroxide groups compared with group cp-Ti. The surface roughness (Ra) measured by a profilometer showed no significant difference (P>0.05). Group AHT showed a lower contact angle and higher surface energy than group cp-Ti. Cell proliferation on group AHT surfaces was significantly higher than on group cp-Ti surfaces (P<0.05). In comparison to group cp-Ti, group AHT enhanced ALP activity (P<0.05). Conclusions: These results suggest that group AHT stimulates osteoblast differentiation.
Evaluation of barley to replace milk by-product in weaning pig’s diet
( Kyung Young Jin ),( Jin Su Hong ),( Dong Wook Sin ),( Hyo Kon Kang ),( Yun Young Jo ),( Geon Il Lee ),( Xing Hao Jin ),( Jae Cheol Jang ),( Jae Hark Jeong ),( Yoo Yong Kim ) 한국축산학회(구 한국동물자원과학회) 2019 한국축산학회지 Vol.61 No.2
The supplementation level of barley was limited because of high contents of fiber in monogastric animals. Barley contained high soluble fiber, thus it could prevent to diarrhea of weaning pigs. Moreover, as the barley break down by enzymes, free sugars come out from the barley, which could be used as an energy source in weaning pigs and replace milk by-products in weaning pig’s diet. Therefore, present study was conducted to investigate the influence of barley to replace milk by-product in weaning pig’s diet on growth performance, blood profile, nutrient digestibility, diarrhea incidence, and economic analysis in weaning pigs. A total of 112 crossbred ([Yorkshire × Landrace] × Duroc, weaned at 28 days of age) piglets were allotted to 4 treatments in a randomized complete block (RCB) design. Each treatment has 7 replications with 4 pigs per pen. Pigs were fed each treatment diet which containing different levels of barley (0%, 10%, 20%, and 30%) at the expense of whey powder and lactose. Three phase feeding programs were used for 6 weeks of growth trial (phase 1: 0-2 weeks; phase 2: 3-4 weeks; phase 3: 5-6 weeks). During 0-2 week, body weight (BW), average daily gain (ADG) and G:F ratio were decreased as barley level increased in the diet (linear response, p < 0.01). In blood profile, blood urea nitrogen was decreased as the barley level increased in the diet (linear, p < 0.01). However, no significant differences were observed in blood glucose level. In nutrient digestibility, crude fat digestibility was linearly increased as barley increased (linear, p < 0.01). The incidence of diarrhea was improved as increasing barley contents in all phases (linear, p < 0.01). These results demonstrated that supplementation of barley to replace milk by-product influenced negatively on growth performance during 0-2 week. However, the incidence of diarrhea and later growth performance from 3 week postweaning were improved as dietary barley level increased.
Earratum to: Evaluation of barley to replace milk by-product in weaning pig’s diet
( Kyung Young Jin ),( Jin Su Hong ),( Dong Wook Sin ),( Hyo Kon Kang ),( Yun Young Jo ),( Geon Il Lee ),( Xing Hao Jin ),( Jae Cheol Jang ),( Jae Hark Jeong ),( Yoo Yong Kim ) 한국축산학회(구 한국동물자원과학회) 2019 한국축산학회지 Vol.61 No.3
Preparation and properties of silver-containing nylon 6 nanofibers formed by electrospinning
Park, Suk-Woo,Bae, Hyun-Su,Xing, Zhi-Cai,Kwon, Oh Hyeong,Huh, Man-Woo,Kang, Inn-Kyu Wiley Subscription Services, Inc., A Wiley Company 2009 Journal of applied polymer science Vol.112 No.4
<P>Nylon 6 nanofibers containing silver nanoparticles (nylon 6/silver) were successfully prepared by electrospinning. The structure and properties of the electrospun fibers were studied with the aid of scanning electron microscopy, transmission electron microscopy, energy-dispersive spectroscopy, and X-ray diffraction. The structural analysis indicated that the fibers electrospun at maximum conditions were straight and that silver nanoparticles were distributed in the fibers. Finally, the antibacterial activities of the nylon 6/silver nanofiber mats were investigated in a broth dilution test against Staphylococcus aureus (Gram-positive) and Klebsiella pneumoniae (Gram-negative) bacteria. It was revealed that nylon 6/silver possessed excellent antibacterial properties and an inhibitory effect on the growth of S. aureus and K. pneumoniae. On the contrary, nylon 6 fibers without silver nanoparticles did not show any such antibacterial activity. Therefore, electrospun nylon 6/silver nanocomposites could be used in water filters, wound dressings, or antiadhesion membranes. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009</P>