Measurement and correlation of phase equilibria in aqueous two-phase systems containing ionic liquid ([EOMiM]Br) and potassium citrate/ammonium citrate/potassium tartrate at different temperatures

Dongdong Wang,Yang Lu,Zhuo Sun,Wei Liang,Dongshu Sun,Changli Qi,ChengZhuo Sheng,Xiaopeng Yu 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.2

An aqueous two-phase system (ATPS) containing an ionic liquid (1-(2-methoxyethyl)-3-methylimidazolium bromide) and three organic salts (K3C6H5O7, (NH4)3C6H5O7, and K2C4H4O6) at different temperatures was designed. Binodal data were correlated using two empirical equations, and tie-line data were fit with the utilization of Bancroft and Othmer-Tobias equations. In the systems investigated, three conclusions were drawn from the study of the phase-forming ability of salt through effective excluded volume, Gibbs free energy of ions, and the phase diagram. First, if the same cations of salt were present, the ability of salt to form phases increased with increasing valence of the anion. Second, the larger the effective excluded volume, the stronger the aforementioned ability of salt in forming phases. Third, salt had more ability to form phases if cations (or anions) contained in the salt possessed higher negative Gibbs free energy when the cation (anion) of the salt was the same. The effect of temperature on ATPSs was also investigated. It was found that it was easier to form ATPSs at lower temperature, and the tie-line slope showed growing absolute values as the temperature was decreased.

Effect of Solid Particles on Cavitation and Lubrication Characteristics of Upstream Pumping Mechanical Seal Liquid Membrane

Huilong Chen,Dongdong Sun,Yuanzheng Wu,Miaomiao Chen,Peilin Zhang 한국유체기계학회 2017 International journal of fluid machinery and syste Vol.10 No.4

In order to investigate the effect of solid particles on the cavitation characteristics and lubricating properties of the micro-gap liquid film in Upstream pumping mechanical seals, the Eulerian multiphase flow model was used to simulate the liquid film with different diameter and volume fraction of solid particles to analyze the influence of the particles on the distribution of vacuole, opening force and friction torque of the film under different working conditions. The results showed that the particles have an inhibitory effect on the cavitation, and the cavitation area and the volume fraction of the bubbles were both decreased. The cavitation area increased with the increase of particle diameter, which indicated that the inhibition of cavitation was weakened with the increase of particle diameter. The cavitation area decreased with the increase of the particle volume fraction, and the volume fraction increased the cavitation inhibition effect. The presence of particles improved the opening force of liquid film to a certain extent and increased with the increase of particle volume fraction, but the effect of particle diameter on opening force was different under different rotating speed and different medium pressure. The friction torque did not change obviously with the particle diameter, and decreased only slightly with the increase of the particle volume fraction. In the working condition range, the cavitation degree is not related to the pressure of the medium, but increases with the increase of the rotational speed, and the cavitation area and volume fraction of bubbles Were significantly decreased when there were solid particles.

Effect of Solid Particles on Cavitation and Lubrication Characteristics of Upstream Pumping Mechanical Seal Liquid Membrane

Chen, Huilong,Sun, Dongdong,Wu, Yuanzheng,Chen, Miaomiao,Zhang, Peilin Korean Society for Fluid machinery 2017 International journal of fluid machinery and syste Vol.10 No.4

In order to investigate the effect of solid particles on the cavitation characteristics and lubricating properties of the micro-gap liquid film in Upstream pumping mechanical seals,the Eulerian multiphase flow model was used to simulate the liquid film with different diameter and volume fraction of solid particles to analyze the influence of the particles on the distribution of vacuole, opening force and friction torque of the film under different working conditions. The results showed that the particles have an inhibitory effect on the cavitation, and the cavitation area and the volume fraction of the bubbles were both decreased.The cavitation area increased with the increase of particle diameter, which indicated that the inhibition of cavitation was weakened with the increase of particle diameter. The cavitation area decreased with the increase of the particle volume fraction, and the volume fraction increased the cavitation inhibition effect. The presence of particles improved the opening force of liquid film to a certain extent and increased with the increase of particle volume fraction, but the effect of particle diameter on opening force was different under different rotating speed and different medium pressure.The friction torque did not change obviously with the particle diameter,and decreased only slightly with the increase of the particle volume fraction.In the working condition range, the cavitation degree is not related to the pressure of the medium, but increases with the increase of the rotational speed, and the cavitation area and volume fraction of bubbles Were significantly decreased when there were solid particles.

The Misaligned Coupling Improvement of Loosely Coupled Transformer with Multi-Receivers for IPT System

Zhou Yufei,Li Dongdong,Wang Yingying,Hong Feng,He Xueru,Liu Shuai,Sun Xiangfeng 대한전기학회 2022 Journal of Electrical Engineering & Technology Vol.17 No.4

The low coupling coeffi cient (CC) of loosely coupled transformer (LCT) can greatly aff ect the effi ciency of inductive power transfer (IPT) system. In order to improve the coupling coeffi cient and misaligned tolerance of LCT, this paper proposes a transformer structure with multiple independent small receiving coils. Respectively in ideal alignment and misalignment mode, the distribution of magnetic force lines and the variation law of CC of independent small receiving coils are analyzed. According to the relationship between the coupling coeffi cient matrix and the mutual inductance, the eff ective coupling coeffi cient (ECC) is deduced, and its variation with the misalignment distance is also analyzed. The ECC of the LCT with multi-receiver (MR) structure is almost unchanged. For the multiple loads' characteristics of receivers, by adopting S/P compensated topology, a 500 W outputs prototype of IPT system is established. The experimental results show that the ECC is improved and tolerance performance to lateral and rotational misalignment of proposed MR structure has good characteristics.

Over-expression of PTEN on proliferation and apoptosis in canine mammary tumors cells

Jinjin Tong,Hua Zhang,Dongdong Sun,Yingxue Wang,Chao Yang,Yun Liu 한국통합생물학회 2016 Animal cells and systems Vol.20 No.6

Phosphatase and tensin homolog (PTEN) is an important tumor-suppressor gene which constitutes an important PI3K/Akt pathway by regulating the signaling of multiple biological processes, including apoptosis, metabolism, cell proliferation, and cell growth has been gaining increasing attention. However, the role of PTEN in regulating apoptosis of canine mammary tumors cells still needs further investigation. In this experiment, the effect of PTEN on proliferation and apoptosis in canine mammary tumors (CMT) cells was analyzed. As a result, gene and protein expression levels of apoptosis-related genes were detected. Eukaryotic expression vector pcDNA3.1+-PTEN were successfully constructed and stably transferred into canine CMT cells after geneticin (G418) selection. After pcDNA3.1+-PTEN transfection, compared with control group, the cells proliferation was inhibited and the cell apoptosis was increased in CMT cells. The expression of p-Akt was decreased and the apoptosis-related genes, such as caspase-3, caspase- 9, and Bax, were increased. These data serve to demonstrate the function of PTEN on apoptosis and gene regulatory in PI3K/Akt pathway in CMT cells. Collectively, our data link the tumorsuppressor activities of PTEN to the machinery controlling cell cycle through the modulation of signaling molecules whose signal target is the functional inactivation of the apoptosis gene product.

Sevoflurane induces neuronal apoptosis via enhancing DNMT3L expression and promoting methylation of PSD95 promoter in postoperative cognitive dysfunction

Ling Yunzhi,Li Xiaohong,Yu Li,Sun Yiyun,Yang Dongdong,Li Zhiyi 대한독성 유전단백체 학회 2021 Molecular & cellular toxicology Vol.17 No.3

Background Postoperative cognitive dysfunction (POCD) is a central nervous system (CNS) complication and occurs quite frequently after anesthesia, especially in elderly patients. DNA (cytosine-5)-methyltransferase 3-like (DNMT3L) is an enzymatically inactive regulatory factor that can modulate gene expression via methylation. Few studies specifically focused on the role of DNMT3L in sevoflurane-induced POCD. Objective The cognitive dysfunction was determined by Morris water maze assay. Hippocampal neuron apoptosis was measured by TdT-mediated dUTP nick-end labeling (TUNEL) assay. Neuron proliferation and apoptosis were measured by cell counting kit-8 (CCK-8) and flow cytometry assay. The expression levels of DNMT3L and postsynaptic density protein-95 (PSD95) were measured by qRT-PCR and western blot. Results The sevoflurane-induced POCD aging rat model was established for in vivo study. Suppression of DNA methylation by 5-Aza-2′-deoxycytidine (5-AZA; a widely used methylation inhibitor) reversed sevoflurane-induced cognitive dysfunction and hippocampal neuron apoptosis in rats. Moreover, sevoflurane enhanced DNMT3L expression and induced methylation of PSD95 promoter in vivo. In vitro, sevoflurane induced neuronal apoptosis and DNMT3L expression to promote PSD95 methylation. Finally, rescue experiments indicated that sevoflurane induced neuron apoptosis by increasing DNMT3L expression and promoting methylation of PDS95 in POCD. Conclusion Sevoflurane induced neuronal apoptosis by increasing DNMT3L expression and promoting methylation of PDS95 in vivo and in vitro, providing a novel therapeutic strategy for POCD.

Doppler LIDAR Measurement of Wind in the Stratosphere

Jihui Dong,Hyunki Cha,김덕현,Sung Hoon Baik,Guocheng Wang,Lei Tang,Zhifeng Shu,Wenjing Xu,Dongdong Hu,Dongsong Sun 한국광학회 2010 Current Optics and Photonics Vol.14 No.3

A mobile direct detection Doppler LIDAR based on molecular backscattering for measurement of wind in the stratosphere has been developed in Hefei, China. First, the principle of wind measurement with direct detection Doppler LIDAR is presented. Then the configuration of the LIDAR system is described. Finally, the primary experimental results are provided and analyzed. The results indicate that the detection range of the designed Doppler LIDAR reached 50 km altitude, and there is good consistency between the molecular Doppler wind LIDAR(DWL) and the wind profile radar(WPR) in the low troposphere.