Influence of Diffuser Vane Number on Energy Loss of Multistage Centrifugal Pump

Tian Xin Wu,Deng Hao Wu,Ting Zhang,Hai Ming Huang,Yue Zhong Wu,Jie Gang Mou 한국유체기계학회 2021 International journal of fluid machinery and syste Vol.14 No.4

As a key component of a multistage pump, the diffuser affects the efficiency of the multistage centrifugal pump. However, the loss mechanism inside the diffuser and links between the loss mechanism and vane numbers of diffuser were still not fully understood. In order to investigate the influence of the number of diffuser vane on the energy loss characteristics of multistage centrifugal pump, this paper analyzes the energy loss characteristics of pump with different number of diffuser vane by utilizing entropy production theory. The results show that under the design condition, when the number of diffuser vane increases to 11, the head is increased by 1.2m and the efficiency is increased by 3%. At the same time, with the increase of the number of diffuser vane, the backflow and eddy phenomena are gradually weakened, flow stream is more stable, the entropy production rate is significantly reduced, but the intensity of pressure pulsation in the diffuser is increased slightly.

Retrospective Evaluation of Discrepancies between Radiological and Pathological Size of Hepatocellular Carcinoma Masses

Tian, Fei,Wu, Jian-Xiong,Rong, Wei-Qi,Wang, Li-Ming,Wu, Fan,Yu, Wei-Bo,An, Song-Lin,Liu, Fa-Qiang,Feng, Li,Liu, Yun-He Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.21

Background: The size of a hepatic neoplasm is critical for staging, prognosis and selection of appropriate treatment. Our study aimed to compare the radiological size of solid hepatocellular carcinoma (HCC) masses on magnetic resonance imaging (MRI) with the pathological size in a Chinese population, and to elucidate discrepancies. Materials and Methods: A total of 178 consecutive patients diagnosed with HCC who underwent curative hepatic resection after enhanced MRI between July 2010 and October 2013 were retrospectively identified and analyzed. Pathological data of the whole removed tumors wereassessed and differences between radiological and pathological tumor size were identified. All patients were restaged using a modified Tumor-Node-Metastasis (TNM) staging system postoperatively according to the maximum diameter alteration. The lesions were classified as hypo-staged, iso-staged or hyper-staged for qualitative assessment. In the quantitative analysis, the relative pre and postoperative tumor size contrast ratio ($%{\Delta}size$) was also computed according to size intervals. In addition, the relationship between radiological and pathological tumor diameter variation and histologic grade was analyzed. Results: Pathological examination showed 85 (47.8%) patients were overestimated, 82 (46.1%) patients underestimated, while accurate measurement by MRI was found in 11 (6.2%) patients. Among the total subjects, 14 (7.9%) patients were hypo-staged and 15 (8.4%) were hyper-staged post-operatively. Accuracy of MRI for calculation and characterized staging was related to the lesion size, ranging from 83.1% to 87.4% (<2cm to ${\geq}5cm$, p=0.328) and from 62.5% to 89.1% (cT1 to cT4, p=0.006), respectively. Overall, MRI misjudged pathological size by 6.0 mm (p=0.588 ), and the greatest difference was observed in tumors <2cm (3.6 mm, $%{\Delta}size=16.9%$, p=0.028). No statistically significant difference was observed for moderately differentiated HCC (5.5mm, p=0.781). However, for well differentiated and poorly differentiated cases, radiographic tumor maximum diameter was significantly larger than the pathological maximum diameter by 3.15 mm and underestimated by 4.51 mm, respectively (p=0.034 and 0.020). Conclusions: A preoperative HCC tumor size measurement using MRI can provide relatively acceptable accuracy but may give rise to discrepancy in tumors in a certain size range or histologic grade. In pathological well differentiated subjects, the pathological tumor size was significantly overestimated, but underestimated in poorly differentiated HCC. The difference between radiological and pathological tumor size was greatest for tumors <2 cm. For some HCC patients, the size difference may have implications for the decision of resection, transplantation, ablation, or arterially directed therapy, and should be considered in staging or selecting the appropriate treatment tactics.

Hierarchical porous ECM scaffolds incorporating GDF-5 fabricated by cryogenic 3D printing to promote articular cartilage regeneration

Wu Jiang,Fu Liwei,Yan Zineng,Yang Yu,Yin Han,Li Pinxue,Yuan Xun,Ding Zhengang,Kang Teng,Tian Zhuang,Liao Zhiyao,Tian Guangzhao,Ning Chao,Li Yuguo,Sui Xiang,Chen Mingxue,Liu Shuyun,Guo Quanyi 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

In recent years, there has been significant research progress on in situ articular cartilage (AC) tissue engineering with endogenous stem cells, which uses biological materials or bioactive factors to improve the regeneration microenvironment and recruit more endogenous stem cells from the joint cavity to the defect area to promote cartilage regeneration.In this study, we used ECM alone as a bioink in low-temperature deposition manufacturing (LDM) 3D printing and then successfully fabricated a hierarchical porous ECM scaffold incorporating GDF-5.Comparative in vitro experiments showed that the 7% ECM scaffolds had the best biocompatibility. After the addition of GDF-5 protein, the ECM scaffolds significantly improved bone marrow mesenchymal stem cell (BMSC) migration and chondrogenic differentiation. Most importantly, the in vivo results showed that the ECM/GDF-5 scaffold significantly enhanced in situ cartilage repair.In conclusion, this study reports the construction of a new scaffold based on the concept of in situ regeneration, and we believe that our findings will provide a new treatment strategy for AC defect repair.

Role of folP1 and folP2 Genes in the Action of Sulfamethoxazole and Trimethoprim Against Mycobacteria

( Tian Zhou Liu ),( Bang Xing Wang ),( Jin Tao Guo ),( Yang Zhou ),( Mugweru Julius ),( Moses Njire ),( Yuan Yuan Cao ),( Tian Wu ),( Zhi Yong Liu ),( Chang Wei Wang ),( Yong Xu ),( Tian Yu Zhang ) 한국미생물 · 생명공학회 2015 Journal of microbiology and biotechnology Vol.25 No.9

The combination of trimethoprim (TMP) and sulfamethoxazole (SMX) has been shown to be active against Mycobacterium tuberculosis (Mtb) in clinical tuberculosis (TB) treatment. However, the mechanism of action of TMP-SMX against Mtb is still unknown. To unravel this, we have studied the effect of TMP and SMX by deleting the folP2 gene in Mycobacterium smegmatis (Msm), and overexpressing the Mtb and Msm folP1/2 genes in Msm. Knocking out of the folP2 gene in Msm reduced the minimum inhibitory concentration of SMX 8-fold compared with wild type. Overexpression of the folP1 genes from Mtb and Msm increased the MICs by 4- and 2-fold in Msm for SMX and TMP, respectively. We show a strong correlation between the expression of folP1 and folP2 genes and TMP-SMX resistance in mycobacteria. This suggests that a combination of FolP2 inhibitor and SMX could be used for TB treatment with a better outcome.

Earthquake-related Crush Injury versus Non-Earthquake Injury in Abdominal Trauma Patients on Emergency Multidetector Computed Tomography: A Comparative Study

Tian-wu Chen,Zhi-gang Yang,Zhi-hui Dong,Zhi-gang Chu,Si-shi Tang,Wen Deng 대한의학회 2011 Journal of Korean medical science Vol.26 No.3

The aim of this study was to investigate features of abdominal earthquake-related crush traumas in comparison with non-earthquake injury. A cross sectional survey was conducted with 51 survivors with abdominal crush injury in the 2008 Sichuan earthquake, and 41with abdominal non-earthquake injury, undergoing non-enhanced computed tomography (CT) scans, serving as earthquake trauma and control group, respectively. Data were analyzed between groups focusing on CT appearance. We found that injury of abdominalwall soft tissue and fractures of lumbar vertebrae were more common in earthquake trauma group than in control group (28 vs 13 victims, and 24 vs 9, respectively; all P <0.05); and fractures were predominantly in transverse process of 1-2 vertebrae among L1-3 vertebrae. Retroperitoneal injury in the kidney occurred more frequently in earthquake trauma group than in control group (29 vs 14 victims, P < 0.05). Abdominal injury in combination with thoracic and pelvic injury occurred more frequently in earthquake trauma group than in control group (43 vs 29 victims, P < 0.05). In conclusion, abdominal earthquake-related crush injury might be characteristic of high incidence in injury of abdominal-wall soft tissue, fractures of lumbar vertebrae in transverse process of 1-2 vertebrae among L1-3 vertebrae, retroperitoneal injury in the kidney, and in combination with injury in the thorax and pelvis.

Four-Leg Object Recognition for Service Robot Based on Top-hat Transformation

Hao Wu,Guohui Tian,Xinran Wang,Fei Lu 보안공학연구지원센터 2014 International Journal of Control and Automation Vol.7 No.12

A method of object recognition for objects with special topological structure is developed based on top-hat transformation for service robot. The objects with four legs are easily detected and recognized by service robot with laser ranger array by this method. First, the top-hat transformation in one dimension is reviewed, then the recognition strategy of self-adapting threshold for objects with special topological structure is proposed, and the general data process for object recognition and position is proposed and analyzed. Experimental results show that the process of object recognition based on top-hat transformation proposed in this article is an effective and accurate application.

Preparation of Graphene–Polypyrrole Hollow Sphere by Pickering Emulsion Method and Their Electrochemical Performances as Supercapacitor Electrode

Sai Wu,Jie Tian,Xianglu Yin,Wei Wu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.5

Graphene–polypyrrole hollow sphere composite was synthesized for the first time via Pickering emulsion polymerization using graphene oxide as Pickering stabilizer. It was found that polypyrrole and graphene were well hybrid and all graphene–polypyrrole composites had a uniform hollow sphere structure, whose diameters gradually decreased as the pyrrole content decreased. The electrochemical properties of the composites as supercapacitor electrode were investigated. The test results displayed that the specific capacitance of the optimal ratio of composite could reach 238 F/g at a current density of 1 A/g, and a 90.7% capacitance retention could be achieved after 1500 cycles, which was a significant improvement compared with the 62.2% retention of pure polypyrrole.

Convolutional Neural Network with Expert Knowledge for Hyperspectral Remote Sensing Imagery Classification

( Chunming Wu ),( Meng Wang ),( Lang Gao ),( Weijing Song ),( Tian Tian ),( Kim-kwang Raymond Choo ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.8

The recent interest in artificial intelligence and machine learning has partly contributed to an interest in the use of such approaches for hyperspectral remote sensing (HRS) imagery classification, as evidenced by the increasing number of deep framework with deep convolutional neural networks (CNN) structures proposed in the literature. In these approaches, the assumption of obtaining high quality deep features by using CNN is not always easy and efficient because of the complex data distribution and the limited sample size. In this paper, conventional handcrafted learning-based multi features based on expert knowledge are introduced as the input of a special designed CNN to improve the pixel description and classification performance of HRS imagery. The introduction of these handcrafted features can reduce the complexity of the original HRS data and reduce the sample requirements by eliminating redundant information and improving the starting point of deep feature training. It also provides some concise and effective features that are not readily available from direct training with CNN. Evaluations using three public HRS datasets demonstrate the utility of our proposed method in HRS classification.

A Typhoon Recognition and Center Position Method based on Fengyun-2 Satellites Data

Wei Tian,Liguang Wu,Weican Zhou,Yuhui Zheng,Jin Wang 보안공학연구지원센터 2014 International Journal of u- and e- Service, Scienc Vol.7 No.6

The recognition and center position methods of typhoon with high accuracy are essential for forecasting and monitoring of tropical cyclones (TCs) in the meteorological applications. We designed the improved adaptive threshold processing algorithms and segmentation of typhoon cloud system by using two value image connecting region labeling algorithm. It shows potential ability in typhoon cloud feature and the recognition of typhoon cloud system in northern hemisphere. We also designed algorithms of locating typhoon center by mathematical morphology. Experimental results show that the typhoon cloud system can be effectively recognized on could imagery and the center of cloud imagery can also be located by the proposed method. Our analysis indicated that typhoon recognition and center position accuracy based on FY-2 satellites data were high recognition rate and accuracy of the center location, and the methods can be applied to meteorological business systems.

Seismic behavior of composite walls with encased steel truss

Yun-tian Wu,Dao-yang Kang,Yi-ting Su,Yeong-Bin Yang 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.22 No.2

This paper studies the seismic behavior of reinforced concrete (RC) walls with encased cold-formed and thin-walled (CFTW) steel truss, which can be used as an alternative to the conventional RC walls or steel reinforced concrete (SRC) composite walls for high-rise buildings in high seismic regions. Seven one-fourth scaled RC wall specimens with encased CFTW steel truss were designed, manufactured and tested to failure under reversed cyclic lateral load and constant axial load. The test parameters were the axial load ratio, configuration and volumetric steel ratio of encased web brace. The behaviors of the test specimens, including damage formation, failure mode, hysteretic curves, stiffness degradation, ductility and energy dissipation, were examined. Test results indicate that the encased web braces can effectively improve the ductility and energy dissipation capacity of RC walls. The steel angles are more suitable to be used as the web brace than the latticed batten plates in enhancing the ductility and energy dissipation. Higher axial load ratio is beneficial to lateral load capacity, but can result in reduced ductility and energy dissipation capacity. A volumetric ratio about 0.25% of encased web brace is believed cost-effective in ensuring satisfactory seismic performance of RC walls. The axial load ratio should not exceed the maximum level, about 0.20 for the nominal value or about 0.50 for the design value. Numerical analyses were performed to predict the backbone curves of the specimens and calculation formula from the Chinese Code for Design of Composite Structures was used to predict the maximum lateral load capacity. The comparison shows good agreement between the test and predicted results.