Effect of guide wall on jet impingement cooling in blade leading edge channel

Qing-Yang Zhao,정희윤,Seok Min Choi,조형희 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.2

The characteristics of fluid flow and heat transfer, which are affected by the guide wall in a jet impinged leading edge channel, have been investigated numerically using three-dimensional Reynolds-averaged Navier–Stokes analysis via the shear stress transport turbulence model and gamma theta transitional turbulence model. A constant wall heat flux condition has been applied to the leading edge surface. The jet-to-surface distance is constant, which is three times that of the jet diameter. The arrangement of the guide wall near the jet hole is set as a variable. Results presented in this study include the Nusselt number contour, velocity vector, streamline with velocity, and local Nusselt number distribution along the central line on the leading edge surface. The average Nusselt number and average pressure loss between jet nozzle and channel exit are calculated to assess the thermal performance. The application of the guide wall is aimed at improving heat transfer uniformity on the leading edge surface. Results indicated that the streamwise guide wall ensures the vertical jet impingement flow intensity and prevents the flow after impingement to reflux into jet flow. Thus, a combined rectangular guide wall benefits the average heat transfer, thermal performance and heat transfer distribution uniformity.

A Data Placement Algorithm for Data Intensive Applications in Cloud

Qing Zhao,Congcong Xiong,Kunyu Zhang,Yang Yue,Jucheng Yang 보안공학연구지원센터 2016 International Journal of Grid and Distributed Comp Vol.9 No.2

Data layout is an important issue which aims at reducing data movements among data centers to improve the efficiency of the entire cloud system. This paper proposes a data-intensive application oriented data layout algorithm. It is based on hierarchical data correlation clustering and the PSO algorithm. The datasets with fixed location have been considered, and both the offline strategy and the online strategy for data layout have been given. As this proposed strategy is aimed at reducing the global amount of data transmissions, and the special permission of the datasets has been introduced, the cost of data transmission can be measured more reasonable. Simulation results show that compared with two classical strategies, our algorithm can reduce the amount of data transmission more effectively.

Effect of Channel Curvature for Jet Impinging on Blade Leading Edge

Qing-Yang Zhao,Eui Yeop Jung,Seok Min Choi,Hyung Hee Cho 대한기계학회 2013 대한기계학회 춘추학술대회 Vol.2013 No.12

The characteristics of fluid flow and heat transfer affected by the curvature variation in a jet impinged leading edge channel have been investigated numerically using three-dimensional Reynolds-averaged Navier-Stokes analysis via shear stress transport turbulence model and γ - Re<SUB>θ</SUB> transitional turbulence model. A constant heat flux condition has been applied on the leading edge surface. Jet to leading edge surface distance is constant as three times of jet diameter. The leading edge curved surface curvature is set as variables by the reason of multiple shape of real turbine blade. Results presented in this study include contour of Nusselt number, velocity vector and local Nusselt number distribution along the central line on the leading edge surface. Based on the data above, the average Nusselt number, stagnation Nusselt number along the central line of leading edge and average pressure supplied on each jet are compared between each case. The varied leading edge curved surfaces change the cross flow intensity which influences the impinging jet flow direction. As a result of the phenomenon of jet flow direction change, the heat transfer on the leading edge is influenced significantly. Result indicates that with the decrease of leading edge curved surface diameter, the cross flow effect improves and heat transfer uniformity decreases. In the case of small diameter leading edge, the average heat transfer decrease and the Nusselt value decreases along the streamwise direction due to the crossflow from upstream jet flow. Besides the heat transfer uniformity, the thermal performance comparison is also investigated in this study.

Effect of various rib arrangements on heat transfer in a semicylinder channel with effusion flow

Zhao, Qing-Yang,Chung, Heeyoon,Jung, Eui Yeop,Cho, Hyung Hee Taylor Francis 2017 NUMERICAL HEAT TRANSFER PART A-APPLICATIONS - Vol.71 No.5

Synthesis, Characterization and Biological Activities of Novel (E)-3-(1-(Alkyloxyamino)ethylidene)-1-alkylpyrrolidine-2,4-dione Derivatives

Zhao-Yong Zhu,Qing-Ming Shi,Bao-Feng Han,Xian-Feng Wang,Sheng Qiang,Chun-Long Yang 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.9

Twenty novel tetramic acid derivatives (E)-3-(1-(alkyloxyamino)ethylidene)-1-alkylpyrrolidine-2,4-diones were synthesized by the reaction of 3-(1-hydroxyethylidene)pyrrolidine-2,4-diones with O-alkyl hydroxylamines. The title compounds were confirmed by IR, 1H NMR, MS and elemental analysis. The structure of compound 6r was further verified by X-ray diffraction crystallography. The bioassays showed that most of the title compounds exhibited noticeable herbicidal and fungicidal activities.

Transcriptome analysis reveals critical genes and key pathways involved in early phyllotaxy development in maize

Yang Zhao,Xiaojian Peng,Wenbo Chai,Yingquan Tan,Qing Dong,Haiyang Jiang,Beijiu Cheng 한국유전학회 2017 Genes & Genomics Vol.39 No.1

Integrated networks of gene expression, hormonal signaling and metabolite sensing regulate phyllotaxy pattern development. In this study, we characterized differentially expressed genes (DEGs) between maize plants with alternate and opposite phyllotaxies. Gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses showed that 2432 DEGs were involved in biological processes, molecular functions, cellular components and many pathways. Importantly, we identified 19 DEGs related to plant hormone signal transduction. Additionally, we identified four main alternative splicing types: skipped exons, retained introns, alternative 50-splice sites, and alternative 30-splice sites, which exhibited different characteristics in the alternate and opposite phyllotaxy libraries. The reliability of the sequencing data was verified through using quantitative real-time reverse transcription PCR analysis of the 19 genes: 15 were validated to play a role in phytohormone signal transduction pathways. Taken together, our data provide new insight into the mechanisms of phyllotaxy pattern development, and will increase our understanding of how relative changes in gene expression determine alternate/opposite phyllotaxy in maize.

Spreading Shape and Area Regulate the Osteogenesis of Mesenchymal Stem Cells

Yang Zhao,Qing Sun,Shurong Wang,Bo Huo 한국조직공학과 재생의학회 2019 조직공학과 재생의학 Vol.16 No.6

BACKGROUND: Mesenchymal stem cells (MSCs) have strong self-renewal ability and multiple differentiation potential. Some studies confirmed that spreading shape and area of single MSCs influence cell differentiation, but few studies focused on the effect of the circularity of cell shape on the osteogenic differentiation of MSCs with a confined area during osteogenic process. METHODS: In the present study, MSCs were seeded on a micropatterned island with a spreading area lower than that of a freely spreading area. The patterns had circularities of 1.0 or 0.4, respectively, and areas of 314, 628, or 1256 lm2. After the cells were grown on a micropatterned surface for 1 or 3 days, cell apoptosis and F-actin were stained and analyzed. In addition, the expression of b-catenin and three osteogenic differentiation markers were immunofluorescently stained and analyzed, respectively. RESULTS: Of these MSCs, the ones with star-like shapes and large areas promoted the expression of osteogenic differentiation markers and the survival of cells. The expression of F-actin and its cytosolic distribution or orientation also correlated with the spreading shape and area. When actin polymerization was inhibited by cytochalasin D, the shaperegulated differentiation and apoptosis of MSCs with the confined spreading area were abolished. CONCLUSION: This study demonstrated that a spreading shape of low circularity and a larger spreading area are beneficial to the survival and osteogenic differentiation of individual MSCs, which may be regulated through the cytosolic expression and distribution of F-actin.

Effects of the Environment and Temperature on the Tribological Behavior of TiZrHfNbTa Refractory High-Entropy Alloy

Qing Zhao,Xi Jin,Xiao hui Shi,Hui jun Yang,Min Zhang,Junwei Qiao 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.8

The tribological behavior of TiZrHfNbTa refractory high-entropy alloy (RHEA) sliding against Si3N4ball was investigatedin the air, deionized water and seawater at room temperature as well as under dry condition at high temperature. The resultsshowed that the TiZrHfNbTa RHEA was composed of single BCC phase. The wear rate in air, deionized water and seawaterreached the maximum value of 3.02 × 10−4 mm3/(Nm), 2 × 10−4 mm3/(Nm) and 3.18 × 10−4 mm3/(Nm) at 10 N, respectively. Moreover, the wear rate in deionized water was much lower than that in air, while the wear rate in seawater was close to thatin air. The wear mechanisms were all transitioned from the abrasive wear to adhesive wear with increasing the normal load. At high temperature, the wear rate increased first and then decreased, reached the maximum value of 2.04 × 10–4 mm3/(Nm)at 500 ℃. In addition, oxidation occurred at 400 ℃. The wear mechanism changed from the abrasive wear to oxidation wearat high temperature.

Effects of PLCE1 Gene Silencing by RNA Interference on Cell Cycling and Apoptosis in Esophageal Carcinoma Cells

Zhao, Li,Wei, Zi-Bai,Yang, Chang-Qing,Chen, Jing-Jing,Li, Dan,Ji, Ai-Fang,Ma, Liang Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.13

Esophageal squamous cell carcinoma (ESCC) is one of the most malignancies with a poor prognosis. The phospholipase $C{\varepsilon}$ gene (PLCE1) encodes a novel ras-related protein effector mediating the effects of R-Ras on the actin cytoskeleton and membrane protrusion. However, molecular mechanisms pertinent to ESCC are unclear. We therefore designed PLCE1-special small interfering RNA and transfected to esophageal squamous cell (EC) 9706 cells to investigat the effects of PLCE1 gene silencing on the cell cycle and apoptosis of ESCC and indicate its important role in the development of ESCC. Esophageal cancer tissue specimens and normal esophageal mucosa were obtained and assayed by immunohistochemical staining to confirm overexpression of PLCE1 in neoplasias. Fluorescence microscopy was used to examine transfection efficiency, while the result of PLCE1 silencing was examined by reverse transcription (RT-PCR). Flow cytometry and annexin V apoptosis assays were used to assess the cell cycle and apoptosis, respectively. Expression of cyclin D1 and caspase-3 was detected by Western-blotting. The level of PLCE1 protein in esophageal cancer tissue was significantly higher than that in normal tissue. After transfection, the expression of PLCE1 mRNA in EC 9706 was significantly reduced, compared with the control group. Furthermore, flow cytometry results suggested that the PLCE1 gene silencing arrested the cell cycle in the G0/G1 phase; apoptosis was significantly higher than in the negative control group and mock group. PLCE1 gene silencing by RNAi resulted in decreased expression of cyclin D1 and increased expression of caspase-3. Our study suggests that PLCE1 may be an oncogene and play an important role in esophageal carcinogenesis through regulating proteins which control cell cycling and apoptosis.

Continuous DC-CIK Infusions Restore CD8⁺ Cellular Immunity, Physical Activity and Improve Clinical Efficacy in Advanced Cancer Patients Unresponsive to Conventional Treatments

Zhao, Yan-Jie,Jiang, Ni,Song, Qing-Kun,Wu, Jiang-Ping,Song, Yu-Guang,Zhang, Hong-Mei,Chen, Feng,Zhou, Lei,Wang, Xiao-Li,Zhou, Xin-Na,Yang, Hua-Bing,Ren, Jun,Lyerly, Herbert Kim Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.6

Background: There are few choices for treatment of advanced cancer patients who do not respond to or tolerate conventional anti-cancer treatments. Therefore this study aimed to deploy the benefits and clinical efficacy of continuous dendritic cell-cytokine induced killer cell infusions in such patients. Materials and Methods: A total of 381 infusions (from 67 advanced cases recruited) were included in this study. All patients underwent peripheral blood mononuclear cell apheresis for the following cellular therapy and dendritic cells-cytokine induced killer cells were expanded in vitro. Peripheral blood T lymphocyte subsets were quantified through flow cytometry to address the cellular immunity status. Clinical efficacy and physical activities were evaluated by RECIST criteria and Eastern Cooperative Oncology Group scores respectively. Logistic regression model was used to estimate the association between cellular infusions and clinical benefits. Results: An average of $5.7{\pm}2.94{\times}10^9$ induced cells were infused each time and patients were exposed to 6 infusions. Cellular immunity was improved in that cytotoxic $CD8^+CD28^+$ T lymphocytes were increased by 74% and suppressive $CD8^+CD28^-$ T lymphocytes were elevated by 16% (p<0.05). Continuous infusion of dendritic cells-cytokine induced killer cells was associated with improvement of both patient status and cellular immunity. A median of six infusions were capable of reducing risk of progression by 70% (95%CI 0.10-0.91). Every elevation of one ECOG score corresponded to a 3.90-fold higher progression risk (p<0.05) and 1% increase of $CD8^+CD28^-$ T cell proportion reflecting a 5% higher risk of progression (p<0.05). Conclusions: In advanced cancer patients, continuous dendritic cell-cytokine induced killer cell infusions are capable of recovering cellular immunity, improving patient status and quality of life in those who are unresponsive to conventional cancer treatment.