Facile microwave-assisted solvothermal synthesis of rod-like aluminum terephthalate [MIL-53(Al)] for CO2 adsorption

Liwei Sun,Meilin Yin,Zhen Li,Shaokun Tang 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.112 No.-

To alleviate environment issues derived from CO2 emission, developing effective and economical methodsfor CO2 capture has attracted much attention for decades. Metal-organic frameworks possess highporosity and stability, which is favorable to the adsorption of small molecules. Herein, an aluminumbasedMOF, aluminum terephthalate [MIL-53(Al)], was synthesized with H2O and N,N0-dimethylformamide as co-solvent via microwave-assisted method for CO2 adsorption. The parametersincluding pre-mixing mode, microwave temperature, microwave power and reaction time were variedto study their influences on crystal structure, morphology and CO2 adsorption capacity of MW-MIL-53(Al). Wherein, MW-MIL-53(Al) prepared with pre-mixing mode of stirring at 130 C, 200 W and 3 h presentshigh crystallinity and rod-like morphology. The synthesized MW-MIL-53(Al) possesses relativelyhigh BET surface area (961 m2/g), pore volume (0.46 cm3/g) and thermal stability (up to 480 C), andits CO2 adsorption capacity is 2.16 mmol CO2/g adsorbent under 25 C and 0.1 MPa, which is higher thanCS-MIL-53(Al) synthesized via conventional solvothermal method at 130 C for 48 h.

Synthesis of bi-functionalized ionic liquid - mesoporous alumina composite material and its CO2 capture capacity

Liwei Sun,Shaokun Tang 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.10

Bi-functionalized ionic liquid (IL) - mesoporous alumina (MA) composite material was synthesized and used for CO2 capture. Ordered mesoporous alumina was synthesized by self-assembly method with aluminum isopropoxide as aluminum source. Then bi-functionalized ionic liquid 1-methoxyethyl-3-methyl imidazole glycinate ([MOEmim][Gly]) was immobilized on mesoporous alumina by ultrasonic-assisted impregnation method. Ordered mesostructure of alumina keeps well in the composite material. Compared with bi-functionalized ionic liquid, thermal stability of the composite material greatly improved. Finally, CO2 capture capacity of IL-MA composite material was studied under different temperatures. On the basis of both capture capacity and capture rate, 40 oC is the optimal temperature. The capture capacity is 1.42mol·mol IL−1 - equivalent to 144mg·g sorbent−1, which is higher than IL or MA alone. Furthermore, the capture capacity of composite material almost maintains constant after eight capture-regeneration cycles.

Printing of self-healable gelatin conductors engineered for improving physical and electrical functions: Exploring potential application in soft actuators and sensors

최건오,Xiaowu Tang,Rixuan Wang,Kaibin Wu,정용진,안태규,김세현,Liwei Mi 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.116 No.-

Significant efforts have been devoted to developing dielectric elastomer actuators owing to their mechanicalflexibilities, silent operation, and muscle-like performances. However, it still remains a challenge todemonstrate the actuators that maintain function when subjected to damage because most soft materialsconstituting such devices are vulnerable to mechanical stresses during repeated operation. Here, selfhealableelectrodes suitable for dielectric elastomer actuators were prepared from an eco-friendlygelatin-based composite including conductive ions and hydrogen bonds. Electrohydrodynamic printingwas used to reproducibly fabricate a custom-made electrode with desired geometry. The printedgelatin-based electrodes were attached onto elastomers to fabricate dielectric elastomer actuators. Thedevices exhibited good actuator operation and, owing to the self-healing capability of the gelatinbasedelectrodes, almost fully recovered their performances with an efficiency of up to 96.8% even afterthe electrodes were damaged. Furthermore, the potential application of the gelatin-based electrode wasexplored by using them as a strain sensor; this sensor showed a sensitive dependence of electrical resistanceon external joint movements. We believe this work provides a useful guideline for designing selfhealableconductive composites that can be effectively used to make printed actuators and sensorsendowed with good ionic conductivity and useful mechanical properties.

Combination of supercritical fluid elution and resin adsorption for removal of procymidone from ginseng extracts

Guangtao Li,Liwei Sun,Shaokun Tang 한국화학공학회 2018 Korean Journal of Chemical Engineering Vol.35 No.4

We propose a new method of resin adsorption (RA) coupled with supercritical fluid elution (SFE) for removal of pesticide residue and recovery of ginsenosides from ginseng extracts. D-101-1 resin was selected as the proper adsorption resin, acetone-n-hexane (4 : 6, v : v) served as the modifier with the flow rate of 1.5mL/min during supercritical CO2 elution of procymidone at 25MPa, 55 oC for 2 h, and absolute ethanol as the modifier at a flow rate of 1mL/min for supercritical CO2 elution of ginsenosides at 20MPa, 60 oC and 1 h. The results showed that the content of procymidone in the final products was only 0.0089mg/kg. Meanwhile, the recovery rate of ginsenosides reached up to 92.5%. RA-SFE procedure provides an efficient approach to remove pesticide residue traces with little loss of active ingredients. The used resin can be recycled without any additional regeneration.

Theoretical and experimental investigation of the effects of an irregular-pitch cutter on vibration in face-milling

Hui Li,Haiqi Zheng,Liwei Tang 대한기계학회 2010 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.24 No.11

In the present work, cutting-force models of single-tooth and multi-teeth face-milling cutters were set up. Based on a spectrum analysis of cutting force, the vibration mechanism of a face-milling cutter of irregular pitch was investigated theoretically. The single-objective function and constraint conditions were derived. A general-purpose irregular-pitch face-milling cutter subsequently was designed and tested, and its performance was compared with that of a regular-pitch cutter. The experimental results showed that the irregular-pitch face-milling cutter not only reduces vibration and noise but also enhances surface-finish quality.

Major ginsenosides from Panax ginseng promote aerobic cellular respiration and SIRT1-mediated mitochondrial biosynthesis in cardiomyocytes and neurons

Huang, Qingxia,Lou, Tingting,Lu, Jing,Wang, Manying,Chen, Xuenan,Xue, Linyuan,Tang, Xiaolei,Qi, Wenxiu,Zhang, Zepeng,Su, Hang,Jin, Wenqi,Jing, Chenxu,Zhao, Daqing,Sun, Liwei,Li, Xiangyan The Korean Society of Ginseng 2022 Journal of Ginseng Research Vol.46 No.6

Background: Aerobic cellular respiration provides chemical energy, adenosine triphosphate (ATP), to maintain multiple cellular functions. Sirtuin 1 (SIRT1) can deacetylate peroxisome proliferator-activated receptor gamma coactivator 1 alpha (PGC-1α) to promote mitochondrial biosynthesis. Targeting energy metabolism is a potential strategy for the prevention and treatment of various diseases, such as cardiac and neurological disorders. Ginsenosides, one of the major bioactive constituents of Panax ginseng, have been extensively used due to their diverse beneficial effects on healthy subjects and patients with different diseases. However, the underlying molecular mechanisms of total ginsenosides (GS) on energy metabolism remain unclear. Methods: In this study, oxygen consumption rate, ATP production, mitochondrial biosynthesis, glucose metabolism, and SIRT1-PGC-1α pathways in untreated and GS-treated different cells, fly, and mouse models were investigated. Results: GS pretreatment enhanced mitochondrial respiration capacity and ATP production in aerobic respiration-dominated cardiomyocytes and neurons, and promoted tricarboxylic acid metabolism in cardiomyocytes. Moreover, GS clearly enhanced NAD⁺-dependent SIRT1 activation to increase mitochondrial biosynthesis in cardiomyocytes and neurons, which was completely abrogated by nicotinamide. Importantly, ginsenoside monomers, such as Rg1, Re, Rf, Rb1, Rc, Rh1, Rb2, and Rb3, were found to activate SIRT1 and promote energy metabolism. Conclusion: This study may provide new insights into the extensive application of ginseng for cardiac and neurological protection in healthy subjects and patients.

Combining Non-Contrast CT Signs With Onset-to-Imaging Time to Predict the Evolution of Intracerebral Hemorrhage

Song Lei,Qiu Xiaoming,Zhang Cun,Zhou Hang,Guo Wenmin,Ye Yu,Wang Rujia,Xiong Hui,Zhang Ji,Tang Dongfang,Zou Liwei,Wang Longsheng,Yu Yongqiang,Guo Tingting 대한영상의학회 2024 Korean Journal of Radiology Vol.25 No.2

Objective: This study aimed to determine the predictive performance of non-contrast CT (NCCT) signs for hemorrhagic growth after intracerebral hemorrhage (ICH) when stratified by onset-to-imaging time (OIT). Materials and Methods: 1488 supratentorial ICH within 6 h of onset were consecutively recruited from six centers between January 2018 and August 2022. NCCT signs were classified according to density (hypodensities, swirl sign, black hole sign, blend sign, fluid level, and heterogeneous density) and shape (island sign, satellite sign, and irregular shape) features. Multivariable logistic regression was used to evaluate the association between NCCT signs and three types of hemorrhagic growth: hematoma expansion (HE), intraventricular hemorrhage growth (IVHG), and revised HE (RHE). The performance of the NCCT signs was evaluated using the positive predictive value (PPV) stratified by OIT. Results: Multivariable analysis showed that hypodensities were an independent predictor of HE (adjusted odds ratio [95% confidence interval] of 7.99 [4.87–13.40]), IVHG (3.64 [2.15–6.24]), and RHE (7.90 [4.93–12.90]). Similarly, OIT (for a 1-h increase) was an independent inverse predictor of HE (0.59 [0.52–0.66]), IVHG (0.72 [0.64–0.81]), and RHE (0.61 [0.54– 0.67]). Blend and island signs were independently associated with HE and RHE (10.60 [7.36–15.30] and 10.10 [7.10–14.60], respectively, for the blend sign and 2.75 [1.64–4.67] and 2.62 [1.60–4.30], respectively, for the island sign). Hypodensities demonstrated low PPVs of 0.41 (110/269) or lower for IVHG when stratified by OIT. When OIT was ≤ 2 h, the PPVs of hypodensities, blend sign, and island sign for RHE were 0.80 (215/269), 0.90 (142/157), and 0.83 (103/124), respectively. Conclusion: Hypodensities, blend sign, and island sign were the best NCCT predictors of RHE when OIT was ≤ 2 h. NCCT signs may assist in earlier recognition of the risk of hemorrhagic growth and guide early intervention to prevent neurological deterioration resulting from hemorrhagic growth.

Load Prediction Based on Optimization Ant Colony Algorithm

Li Wei,Tang Jingmin,Ma Han,Fan Min,Liu Simiao,Wang Jie 대한전기학회 2023 Vol.18 No.1

Short-term load in the power system is associated with huge computational consumption and low model utilization. Large input fl uctuation tends to increase the training error of the neural network prediction model and reduce its generalization ability. To cope with this problem, this study aimed to introduce a method of radial basis function neural network algorithm based on least squares support vector machine algorithm. Based on the electricity market in an area of Yunnan province, the short-term loads were forecasted with historical data. First, the ant colony algorithm was improved using the chaos theory. Second, the improved ant colony was used to search least squares support vector machine and output the optimal parameters of the model. Then, the optimized model was used to train the data samples, and the output regression machine was used to provide better structures and parameters for the radial basis function neural network. The fi ndings showed that compared with multiple prediction methods, the algorithm in this paper reduces the learning time and improves the fi tting degree of the algorithm on the basis of improving the prediction accuracy. It shows that the algorithm in this paper has great advantages and good application prospects.

Load Prediction Based on Optimization Ant Colony Algorithm

Li Wei,Tang Jingmin,Ma Han,Fan Min,Liu Simiao,Wang Jie 대한전기학회 2023 Journal of Electrical Engineering & Technology Vol.18 No.1

Short-term load in the power system is associated with huge computational consumption and low model utilization. Large input fluctuation tends to increase the training error of the neural network prediction model and reduce its generalization ability. To cope with this problem, this study aimed to introduce a method of radial basis function neural network algorithm based on least squares support vector machine algorithm. Based on the electricity market in an area of Yunnan province, the short-term loads were forecasted with historical data. First, the ant colony algorithm was improved using the chaos theory. Second, the improved ant colony was used to search least squares support vector machine and output the optimal parameters of the model. Then, the optimized model was used to train the data samples, and the output regression machine was used to provide better structures and parameters for the radial basis function neural network. The findings showed that compared with multiple prediction methods, the algorithm in this paper reduces the learning time and improves the fitting degree of the algorithm on the basis of improving the prediction accuracy. It shows that the algorithm in this paper has great advantages and good application prospects.