Numerical study on heat transfer effects of cavitating and flashing flows based on homogeneous mixture model

Jin, Mei-Shan,Ha, Cong-Tu,Park, Warn-Gyu Elsevier 2017 INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER - Vol.109 No.-

<P><B>Abstract</B></P> <P>A numerical study on heat transfer effects of cavitating and flashing flows was conducted by employing a compressible homogeneous mixture approach. A dual-time preconditioned method was applied to enhance the efficiency and accuracy of the computations under various flow conditions. A sensitivity analysis of the empirical coefficients used to access the predictive capability of the existing mass transfer models was assessed for cavitating flows in a converging-diverging nozzle. To confirm the use of the calibrated empirical coefficients, computations of the water flows over a cylindrical head form and a Clark-Y hydrofoil were then carried out. The results obtained indicate an overall good agreement with the experimental data. Finally, the thermal effects on the phase change process were confirmed through an examination of a flashing flow along with thermo-fluid flows. The predicted results also show a good agreement with the experimental data. In conclusion, the existing system was shown to be effective in quantitatively predicting the thermal effects of the phase change processes, and can be used to examine the hydro- and thermodynamics of multiphase flows.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A numerical study of cavitating and flashing flows was conducted by employing a compressible homogeneous mixture approach. </LI> <LI> The system dominates pressure-driven vaporization and temperature-driven vaporization together. </LI> <LI> Phase change model’s dependency of model coefficients is assessed. </LI> <LI> The influence of thermal effects on evaporation process is proved by examining a flashing flow. </LI> </UL> </P>

Numerical Analysis of Multiphase Flows in a Converging-Diverging Nozzle Under High Temperature Conditions

Mei-Shan Jin,Cong-Tu Ha,Jae-Jun Jeong,Warn-Gyu Park 한국전산유체공학회 2014 한국전산유체공학회 학술대회논문집 Vol.2014 No.10

Numerical analysis of cavitating flow past an axisymmetric cylinder with comparison to experiments

Mei-Shan Jin,박원규,Chul-Min Jung 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.12

Simulation of cavitating flow is of practical importance for many engineering systems such as propellers, pump impellers, nozzles, injectors, and torpedoes. In this study, a two-phase flow solver based on a homogeneous mixture model was developed. Computations were carried out for an axisymmetric cylinder, and the present code was validated by comparing the calculation results with experimental results. The results showed that the system is suitable for simulating evaporation and condensation processes in water flow. What’s more, the changes of cavity length with various operational conditions were calculated including the water depth, angle of attack, and free stream velocity. The conditions for cavitation inception were also studied to show the relationship between the operational conditions in multiphase flows.

Numerical study of ventilated cavitating flows with free surface effects

Mei-Shan Jin,Cong-Tu Ha,박원규 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.12

Cavitating flow is usually formed on the surface of a high-speed underwater object. When the object moves near the free surface athigh speed, the cavitation signature becomes a main factor to be overcome by the sensors of a military satellite. This paper studies thefree surface effect on the ventilated cavitation process. The governing equations are Navier-Stokes equations based on a homogeneousmixture model. The multiphase flow solver used here relies on an implicit preconditioning scheme in curvilinear coordinates. The cavitationmodel used is a new cavitation model developed by Merkle et al. (2006). Computations of free surface effects were carried out witha NACA0012 hydrofoil to enable comparisons with experimental data presented in the literature. Calculations were then performed consideringthe ventilated cavitation process, including the effect of a noncondensable gas with free surface effect.

Terrabacter ginsengisoli sp. nov., isolated from ginseng cultivating soil

Mei-Fang Jin,Xiao-Tian Quan,주베르,Qing-Zhen Liu,Hong Shan Yu,임완택 한국미생물학회 2018 The journal of microbiology Vol.56 No.5

A Gram-positive, strictly aerobic, nonmotile, yellowish, coccus- rod-shaped bacterium (designated Gsoil 653T) isolated from ginseng cultivating soil was characterized using a polyphasic approach to clarify its taxonomic position. The strain Gsoil 653T exhibited optimal growth at pH 7.0 on R2A agar medium at 30°C. Phylogenetic analysis based on 16S rRNA gene sequence similarities, indicated that Gsoil 653T belongs to the genus Terrabacter of the family Humibacillus, and was closely related to Terrabacter tumescens DSM 20308T (98.9%), Terrabacter carboxydivorans PY2T (98.9%), Terrabacter terrigena ON10T (98.8%), Terrabacter terrae PPLBT (98.6%), and Terrabacter lapilli LR-26T (98.6%). The DNA G + C content was 70.5 mol%. The major quinone was MK-8(H4). The primary polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidyl-ethanolamine. The predominant fatty acids were iso-C15:0, iso-C16:0, iso-C14:0, and anteiso-C15:0, as in the case of genus Terrabacter, thereby supporting the categorization of strain Gsoil 653T. However, the DNA-DNA relatedness between Gsoil 653T and closely related strains of Terrabacter species was low at less than 31%. Moreover, strain Gsoil 653T could be both genotypically and phenotypically distinguished from the recognized species of the genus Terrabacter. This isolate, therefore, represents a novel species, for which the name Terrabacter ginsengisoli sp. nov. is proposed with the type strain Gsoil 653T (= KACC 19444T = LMG 30325T).

Nickel‑based N/S‑dual doped graphene/carbon nanotubes electrocatalyst for oxygen evolution

Jin‑Chi Jiang,Jiamin Liu,Yingai Piao,Mei‑Shan Zhang,Long‑Yue Meng 한국탄소학회 2023 Carbon Letters Vol.33 No.1

Hydrogen energy is a promising source of renewable and clean energy for various industries, such as chemical, automobile, and energy industries. Electrolysis of water is one of the basic methods for the production of hydrogen energy. However, the high overpotential of the oxygen evolution reaction (OER) in water electrolysis has hindered the effective production of hydrogen using this method. Thus, the development of high-efficiency non-precious metal-based electrocatalysts for OER is extremely significant. In this study, we adopted a one-step hydrothermal method to fabricate Ni-based catalysts with N/Sdual doped graphene oxide/carbon nanotube (GO/CNT) supports using thiourea ( CH4N2S) and urea as the S source and the N source. It was observed that the amount of thiourea utilized in the synthesis of the catalyst affected the morphology, composition, and the electrochemical properties of the catalyst. For a GO/CNT-to-thiourea mass ratio of 1:10, the catalyst exhibited the highest activity, where the OER overpotential was 320 mV at a current density of 10 mA/cm2. This was attributed to the high specific surface area, high conductivity, and fast electron transport channels of the N/S-dual doped GO/ CNT composite. Furthermore, sulfurization of the Ni particles to form nickel sulfide played a significant role in enhancing the catalytic performance.

Two new ursane-type triterpenoid saponins from Elsholtzia bodinieri

Jin-Dong Zhong,Xue-Wei Zhao,Xuan-Qin Chen,Hong-Mei Li,Chin-Ho Chen,Xue-Shan Xia,Rong-Tao Li 대한약학회 2016 Archives of Pharmacal Research Vol.39 No.6

Two new ursane-type triterpenoid saponins,bodiniosides M (1) and N (2), along with three knownsaponins, oblonganosides I (3), pseudobuxussaponin B (4)and bodinioside A (5), were isolated from the aerial partsof Elsholtzia bodinieri. The structures of compounds 1 and2 were characterized by spectroscopic data as well as acidhydrolysis and GC analysis as 3-O-b-D-xylopyranosyl-19ahydroxy-23-acetoxy-urs-12(13)-en-28-oic acid 28-O-a-Lrhamnopyranosyl-(1-2)-b-D-glucopyranoside and 3-O-b-Dglucopyranosyl-2a,19a-dihydroxy-urs-12(13)-en-28,20blactone. Compounds 1 and 5 exhibited potent anti-HCVactivities in vitro with a selective index of 6.53 and 4.41,respectively.

Clinical and Pathologic Features of Multifocal and Multicentric Breast Cancer in Chinese Women: A Retrospective Cohort Study

Mei-rong Zhou,Zhong-hua Tang,Jing Li,Jin-Hu Fan,Yi Pang,Hong-jian Yang,Shan Zheng,Jing-qiao Bai,Ning Lv,You-Lin Qiao,Feng Xu,Hai-zhi Qi 한국유방암학회 2013 Journal of breast cancer Vol.16 No.1

Purpose: This study aims to analyze the clinical-pathological characteristics of multifocal and multicentric breast cancer (MMBC) in Chinese women. Methods: Sixty-seven cases with MMBC were randomly collected and reviewed at seven hospitals in representative districts of China during 1999 to 2008. Results: The incidence of MMBC in breast cancer in China was 1.75%. Compared to those with unifocal breast cancer, women with MMBC were more likely to have larger tumor size, lymph node metastasis (59.70% vs. 45.62%) and stage III to IV (46.26% vs. 21.10%). The peak age at onset of MMBC was 40 to 49 years old and has been gradually increasing during 1999 to 2008. Most of the MMBC women were treated with surgery and adjuvant therapy. Conclusion: In China, the incidence of MMBC in breast cancer is significantly lower than that in Western countries. Compared to unifocal breast cancer, MMBC is biologically more aggressive. Most MMBC women underwent mastectomy, instead of breast conservation surgery.

Effects of enzymolysis and fermentation of Chinese herbal medicines on serum component, egg production, and hormone receptor expression in laying hens

Mei Hong Jiang,Tao Zhang,Qing Ming Wang,Jin Shan Ge,Lu Lu Sun,Meng Qi Li,Qi Yuan Miao,Yuan Zhao Zhu Asian Australasian Association of Animal Productio 2024 Animal Bioscience Vol.37 No.1

Objective: In the present study, we aimed to investigate the effects of enzymolysis fermentation of Chinese herbal medicines (CHMs) on egg production performance, egg quality, lipid metabolism, serum reproductive hormone levels, and the mRNA expression of the ovarian hormone receptor of laying hens in the late-laying stage. Methods: A total of 360 Hy-Line Brown laying hens (age, 390 days) were randomly categorized into four groups. Hens in the control (C) group were fed a basic diet devoid of CHMs, the crushed CHM (CT), fermented CHM (FC), and enzymatically fermented CHM (EFT) groups received diets containing 2% crushed CHM, 2% fermented CHM, and 2% enzymatically fermented CHM, respectively. Results: Compared with crushed CHM, the acid detergent fiber, total flavonoids, and total saponins contents of fermented CHM showed improvement (p<0.05); furthermore, the neutral and acid detergent fiber, total flavonoids, and total saponins contents of enzymatically fermented CHM improved (p<0.05). At 5 to 8 weeks, hens in the FC and EFT groups showed increased laying rates, haugh unit, albumin height, yolk color, shell thickness, and shell strength compared with those in the C group (p<0.05). Compared with the FC group, the laying rate, albumin height, and Shell thickness in the EFT group was increased (p<0.05). Compared with the C, CT, and FC groups, the EFT group showed reduced serum total cholesterol and increased serum luteinizing hormone levels and mRNA expressions of follicle stimulating hormone receptor and luteinizing hormone receptor (p<0.05). Conclusion: These results indicated that the ETF group improved the laying rate and egg quality and regulated the lipid metabolism in aged hens. The mechanism underlying this effect was likely related to cell wall degradation of CHM and increased serum levels of luteinizing hormone and mRNA expression of the ovarian hormone receptor.

Terrabacter ginsengisoli sp. nov., isolated from ginseng cultivating soil

Jin, Mei-Fang,Quan, Xiao-Tian,Siddiqi, Muhammad Zubair,Liu, Qing-Zhen,Yu, Hong-Shan,Im, Wan-Taek MICROBIOLOGICAL SOCIETY OF KOREA 2018 JOURNAL OF MICROBIOLOGY -SEOUL- Vol.56 No.5

A Gram-positive, strictly aerobic, nonmotile, yellowish, coccus-rod-shaped bacterium (designated Gsoil <TEX>$653^T$</TEX>) isolated from ginseng cultivating soil was characterized using a polyphasic approach to clarify its taxonomic position. The strain Gsoil <TEX>$653^T$</TEX> exhibited optimal growth at pH 7.0 on R2A agar medium at <TEX>$30^{\circ}C$</TEX>. Phylogenetic analysis based on 16S rRNA gene sequence similarities, indicated that Gsoil <TEX>$653^T$</TEX> belongs to the genus Terrabacter of the family Humibacillus, and was closely related to Terrabacter tumescens DSM <TEX>$20308^T$</TEX> (98.9%), Terrabacter carboxydivorans <TEX>$PY2^T$</TEX> (98.9%), Terrabacter terrigena <TEX>$ON10^T$</TEX> (98.8%), Terrabacter terrae <TEX>$PPLB^T$</TEX> (98.6%), and Terrabacter lapilli <TEX>$LR-26^T$</TEX> (98.6%). The DNA G + C content was 70.5 mol%. The major quinone was MK-8(<TEX>$H_4$</TEX>). The primary polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidyl-ethanolamine. The predominant fatty acids were <TEX>$iso-C_{15:0}$</TEX>, <TEX>$iso-C_{16:0}$</TEX>, <TEX>$iso-C_{14:0}$</TEX>, and <TEX>$anteiso-C_{15:0}$</TEX>, as in the case of genus Terrabacter, thereby supporting the categorization of strain Gsoil <TEX>$653^T$</TEX>. However, the DNA-DNA relatedness between Gsoil <TEX>$653^T$</TEX> and closely related strains of Terrabacter species was low at less than 31%. Moreover, strain Gsoil <TEX>$653^T$</TEX> could be both genotypically and phenotypically distinguished from the recognized species of the genus Terrabacter. This isolate, therefore, represents a novel species, for which the name Terrabacter ginsengisoli sp. nov. is proposed with the type strain Gsoil <TEX>$653^T$</TEX> (<TEX>$=KACC\;19444^T=LMG\;30325^T$</TEX>).