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Chao Li,Baihong Li,Guoming Gao,Lijun Zhang,Shu Zhang,Lei Zhang,Jun Xiang,Song Hu,Yi Wang,Xun Hu 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.125 No.-
Drying at 100 C is a common practice for processing many biomasses for their further thermochemicalconversion via the routes such as pyrolysis. The drying temperature of 100 C is low, but might not be toolow to cause any impact on pyrolytic behaviors of a biomass feedstock. In this study, varied scenarios ofthermal pretreatment of poplar sawdust (oven-drying, boiling in water and microwave heating) at 100 Cwere screened for probing their potential influence on the pyrolytic behaviors at 500 and 750 C. Comparing with oven-drying, boiling in water (cooking) and microwave heating at 100 C could removesome oxygen-containing species, increasing carbon content of the pretreated sawdust and promotingcarbonization in pyrolysis. This enhanced formation of biochar, heavy p-conjugated organics in bio-oil,but suppressed generation of gas. The cooking or microwave heating pretreatment also promoted aromatizationto form the biochar of higher thermal stability, higher crystallinity, and higher aromatic degree,due to the enhanced deoxygenation reactions in the pyrolysis. The in-situ IR characterization suggestedthat microwave pretreatment promoted generation of unsaturated ketones and also the species with olefinicC = C, favoring their further aromatization. The cooking pretreatment impacted transformationroutes of the oxygen-containing organics, thus modifying pyrolysis behaviors of the pretreated sawdust.
Cytotoxic Isoflavanones from Uraria clarkei
Xiang-Zhong Huang,Xi-Shan Bai,Hui Liang,Chao Wang,Wen-Juan Li,Junming Guo,Zhi-Yong Jiang 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.5
Two new isoflavanones, (3R) 5,7,3',4'-tetrahydroxy-2'-methoxyisoflavanone (1) and (3R) 5',8-di-(γ,γ- dimethylallyl)-2',5-dihydroxyl-4',7-dimethoxyl-isoflavanone (2), were isolated from Uraria clarkei, together with two known compounds dalbergioidin (3), 5,7-dihydroxy-2',4'-dimethoxyisoflavanone (4). The structures involving the absolute configuration of the new compounds were well elucidated by MS, IR, UV, CD, 1D and 2D NMR analyses. Cytotoxicity of the four compounds were assessed, results suggested that compound 2 possessed well cytotoxic activity, against the Hela, K562, and HL60 cell lines with IC50 values of 28.0, 40.6 and 35.1 μM, respectively.
Experimental and numerical studies of stress/strain characteristics in riveted aircraft lap joints
Chao Zeng,Wei Tian,Xiang Yao Liu,Jiu Tian Xue 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.7
The fatigue property of riveted lap joint is greatly related to the riveting-induced residual stress, especially the stress distribution on the faying surface. However, an accurate study of the residual stress characteristics in the riveted sheet could be very difficult. In this paper, both numerical and experimental investigations were carried out on the stress/strain characteristics in riveted aircraft lap joints. A special specimen was designed for the test of strain variations on the faying surface of the sheet by microstrain gages. For the numerical simulation, the rivet squeezing process was analyzed using the explicit dynamic finite element (FE) method, whilst a general static FE analysis was employed for the elastic springback after the squeeze force was removed. A comparison of the strain variations between the experimental results and FE simulations shows a general good agreement, although there may be some difference for points measured near the hole surface. The FE analysis reveals that both compressive and tensile residual stresses could be introduced in the riveted sheet. Massive compressive residual stress can be created in the near-surface layer of the hole. However, the stress level is not always increased with increasing the squeeze force, and so is the improvement of fatigue life observed. Further study is still necessary to account for the fatigue life decreasing effect caused by a high squeeze force.
Resource recovery and harmless treatment of waste oil-in-water drilling fluid
Chao Tang,Shui Xiang Xie 대한환경공학회 2017 Environmental Engineering Research Vol.22 No.3
Destablization and demulsification is a difficult task for the treatment of waste oil-in-water drilling fluid because of its “three-high” characteristics: emulsification, stabilization and oiliness. At present, China is short for effective treating technology, which restricts cleaner production in oilfield. This paper focused on technical difficulties of waste oil-in-water drilling fluid treatment in JiDong oilfield of China, adopting physical-chemical collaboration demulsification technology to deal with waste oil-in-water drilling fluid. After oil-water-solid three-phase separation, the oil recovery rate is up to 90% and the recycled oil can be reused for preparation of new drilling fluid. Meanwhile, harmless treatment of wastewater and sludge from waste oil-in-water drilling fluid after oil recycling was studied. The results showed that wastewater after treated was clean, contents of chemical oxygen demand and oil decreased from 993 mg/L and 21,800 mg/L to 89 mg/L and 3.6 mg/L respectively, which can meet the requirements of grade one of “The National Integrated Wastewater Discharge Standard” (GB8978); The pollutants in the sludge after harmless treatment are decreased below the national standard, which achieved the goal of resource recovery and harmless treatment on waste oil-in-water drilling fluid.
Quasi-optical design and analysis of a remote steering launcher for CFETR ECRH system
Chao Zhang,Wang Xiaojie,Wu Dajun,Tang Yunying,Wang Hanlin,Li Dingzhen,Liu Fukun,Wu Muquan,Yan Peiguang,Gao Xiang,Li Jiangang 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.5
In order to optimize the operational safety and reliability of the upper launcher for the CFETR ECRH system, a design of the launcher for NTM control based on the remote steering concept is currently being carried out for comparison with the front steering equivalent. This paper presents the layout design and analysis of the quasioptical system in the remote steering launcher. A 3D visual quasi-optical design tool has been developed for the quasi-optical system, which can parameterize modeling, perform general astigmatic beam calculation and show the accurate beam propagation path in the upper port. Three identical sets of quasi-optical modules are arranged in the launcher, and each one consists of two fixed double-curvature focusing mirrors, which focus and reflect the steering beams ( 12◦–12◦) from two square corrugated waveguides. The beam characteristics at the resonance layer are described, and the average beam radius is < 100 mm. The peak head loads on the surfaces of the two fixed mirrors are 1.63 MW/m2 and 1.52 MW/m2. The position and size of the beam channel in the blanket are obtained, and the opening apertures on the launcher-facing and plasma-facing sides of the blanket module are 0.54 m2 and 0.4 m2, respectively.
Conceptual design and analysis of remote steering system for CFETR ECRH system
Chao Zhang,Xiaojie Wang,Dajun Wu,Yunying Tang,Hanlin Wang,Dingzhen Li,Fukun Liu,Muquan Wu,Peiguang Yan,Xiang Gao,Jiangang Li Korean Nuclear Society 2024 Nuclear Engineering and Technology Vol.56 No.2
In order to optimize the operational safety and reliability of the upper launcher for the CFETR ECRH system, a design of the launcher based on the remote steering concept is currently being carried out for comparison with the front steering equivalent. This paper presents the remote steering system's conceptual design and simulation analysis. A Square Corrugated Waveguide (SCW) of 65 × 65 mm has been designed with an optimized length of 9.35 m. By changing the relative length of the waveguide, the transmission efficiency of the SCW is optimized within the range of steering angles ±12°. Different error factors are investigated in detail, and corresponding acceptable error ranges are provided. Considering these error factors and ignoring ohmic losses and thermal effects, the relative transmission efficiency of the SCW is estimated to be >98 % within the steering angle range. A matching steering unit for the SCW is designed, which consists of an ellipsoidal focusing mirror and a steerable flat mirror. The detailed design of the steerable mirror motion trajectory is presented. Also, the influence of the possible beam incident errors caused by the steering unit on the transmission efficiency is analyzed in detail.
Xiang Zou,Chang-fa Chen,Xia-chang Qi,Jiang-chao Qian,Ju Chu,Ying-ping Zhuang,Si-liang Zhang,Wei Zeng,Wan-jun Li 한국생물공학회 2010 Biotechnology and Bioprocess Engineering Vol.15 No.6
Improvement of Erythromycin A (Er-A) production and purity by metabolic engineering of the industrial erythromycin-producing strains Saccharopolyspora erythraea strians ZL1004 and ZL1007, in which the amounts of tailoring enzymes EryK (a P450 hydroxylase)and EryG (an S-adenosylmethionine-dependent O-methyltransferase)for biotransformation of Erythromycin D to Er-A were modulated, was performed in a 50 L fermentor. Addition of 15 g/L of corn steep liquor to the medium increased Er-A production; maximum Er-A production was 8,196 U/mL at 191 h, which was 81.8% higher than that of control (4,507 U/mL at 184 h). Er-B impurities were completely eliminated, whereas Er-C impurities were only 153 U/mL at 191 h. Analysis of intra- and extracellular metabolites and key enzyme activities in central carbon metabolism revealed that the pool of TCA cycle intermediates was enhanced by the addition of corn steep liquor and induced an increase in erythromycin biosynthesis. There were no significant differences between strains ZL1004 and ZL1007 regarding Er-A production and impurity accumulation. Compared to wild type strain,Er-A production was improved by 23.9% while Er-C was reduced by 83.9% and Er-B was completely eliminated. Furthermore, fermentation of recombinant strain ZL1004was successfully scaled up from laboratory scale (50 L fermentor) to industrial scale (25 and 132 m3), with similar levels of Er-A production and purity obtained.
Yan-chao Wang,Jin-miao Lu,Hui-zi Jin,Ai-niu Ma,Jin-yang Zhang,Nian Gong,Qi Xiao,Bin Zhu,Ying-fang Lv,Na Yu,Wei-dong Zhang,Yong-xiang Wang 한국영양학회 2014 Nutrition Research and Practice Vol.8 No.2
BACKGROUND: Groundwater is believed to possess many beneficial effects due to its natural source of various minerals. In this study, we examined the effects of natural Jeju groundwater S1 (SamdasooTM), S2 and S3 pumped up from different locations of Jeju Island, Korea, along with local tap water, on body weight gain, serum lipids and lipoproteins, and liver histopathology in high-fat diet-induced hyperlipidemic rats. MATERIALS/METHODS: Rats were randomly and equally divided into 6 groups. Different water samples were supplied to the hyperlipidemic rats as their daily drinking water and the widely-used anti-hyperlipidemic drug simvastatin was used as a positive control. Body weight, serum lipids and lipoproteins were measured weekly. Liver weight, liver index and liver histopathology were examined after the execution of the rats. RESULTS: After drinking Jeju groundwaters for two months, S2 but not S3 significantly reduced weight growth and serum triglycerides levels and increased high density lipoprotein-C (HDL-C) without affecting total cholesterol or LDL-C. S1 and particularly S2 significantly reduced the severity of liver hypertrophy and steatosis. All Groundwaters had much higher contents of vanadium (S3>S2>S1>>tap water) whereas S1 and S2 but not S3 markedly blocked autoxidation of ferrous ions. CONCLUSION: Jeju Groundwater S1 and particularly S2 exhibit protective effects against hyperlipidemia and fatty liver and hypothesize that the beneficial effect of Jeju Groundwaters may be contributed from blockade of autoxidation of ferrous ions rather than their high contents of vanadium.