124 research outputs found

    Investigation on forced vibration of turbocharger turbine in pulsation flow

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    Variable guide vanes turbines are widely applied in turbocharger. To assess the effects of pulsation inlet conditions on the aerodynamic excitation and the forced vibration of turbine wheel, the weak fluid structure interaction method was adopted. Firstly, a pulsation flow with the frequency of 60 Hz (which corresponds to the engine speed of 2400 r/min) was applied at the turbine inlet to conduct the unsteady flow calculation. The results show that the aerodynamic loads are highly influenced by the pulsation inlet conditions, which fluctuate with the inlet pulsation wave in a pulse cycle, and the maximum and minimum blade load corresponding to the peak and trough of the inlet pulsation wave respectively. For the forced vibration analysis of turbine wheel, the calculated aerodynamic loads in pulsation flow were imposed as the loading boundaries to perform the harmonic vibration and transient structural response by FE calculations, based on the natural frequency and mode of the blade disk. The results show that the forced response of the blade disk not only reflects the contribution of low frequency pulsation excitations but also contains the high frequency pressure fluctuations caused by rotor rotation

    Study on flow unit division and production dynamics of tight sandstone reservoir in Huaqing oilfield

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    758-764In this paper, the Chang 6 ultra-low permeability reservoirs in Huaqjing area of Ordos Basin are studied. The reservoir is divided into four types of flow units by using Q-type multi-parameter clustering analysis and SPSS statistical analysis software. The characteristics of reservoir physical properties, sedimentary characteristics, capillary pressure curve and production dynamics were analyzed. The rationality of the results were verified from the static and dynamic points of view. Results show that I type flow unit has good reservoir properties and development effect is fast. The main development target is to maintain long-term stability. The distribution areas of II and III types are large, and cover the main production layer of oil field development and the remaining oil enrichment area. The reservoir properties of the IV type flow unit are worst, and the development is difficult. Efficient development of such reservoirs through the scientific division of the flow unit is important and of practical significance

    Proteomic Profile of Carbonylated Proteins Screen Regulation of Apoptosis via CaMK Signaling in Response to Regular Aerobic Exercise

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    To research carbonylated proteins and screen molecular targets in the rat striatum on regular aerobic exercise, male SpragueDawley rats (13 months old, n = 24) were randomly divided into middle-aged sedentary control (M-SED) and aerobic exercise (M-EX) groups (n = 12 each). Maximum oxygen consumption (VO2max) gradually increased from 50%ā€“55% to 65%ā€“70% for a total of 10 weeks. A total of 36 carbonylated proteins with modifed oxidative sites were identifed by Electrospray IonizationQuadrupole-Time of Flight-Mass Spectrometer (ESI-Q-TOF-MS), including 17 carbonylated proteins unique to the M-SED group, calcium/calmodulin-dependent protein kinase type II subunit beta (CaMKIIļæ½), and heterogeneous nuclear ribonucleoprotein A2/B1 (Hnrnpa2b1), among others, and 19 specifc to the M-EX group, ubiquitin carboxyl-terminal hydrolase isozyme L1 (UCHL1), and malic enzyme, among others. Regular aerobic exercise improved behavioral and stereological indicators, promoted normal apoptosis (P \u3c 0.01), alleviated carbonylation of the CaMKIIļæ½ and Hnrnpa2b1, but induced carbonylation of the UCH-L1, and signifcantly upregulated the expression levels of CaMKIIļæ½, CaMKIIļæ½, and Vdac1 (p \u3c 0.01) and Hnrnpa2b1 and UCH-L1 (p \u3c 0.01), as well as the phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin pathways (PI3K/Akt/mTOR) pathway-related genes Akt and mTOR. Regular aerobic exercise for 10 weeks (incremental for the frst 6 weeks followed by constant loading for 4 weeks) enhanced carbonylation of CaMKIIļæ½, Hnrnpa2b1, and modulated apoptosis via activation of CaMK and phosphoinositide 3-kinase/protein kinase B/mTOR signaling. It also promoted normal apoptosis in the rat striatum, which may have protective efects in neurons

    Nonalcoholic fatty liver associated with impairment of kidney function in nondiabetes population

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    Background: Nonalcoholic fatty liver disease (NAFLD) is associated with the increased burden of kidney. However, there is still no large population study to explore the potential relationship between NAFLD and mild kidney function damage (MKFD) after adjusted for confounding factors. This study is to test the hypothesis that NAFLD is associated with MKFD under controlling the effects of confoun-ding factors. Materials and methods: Levels of serum fasting glucose, creatinine, cholesterol, triglyceride, alanine aminotransferase and aspartate aminotransferase were analyzed from 1412 Chinese Han adults. Questionnaire and physical examination were performed to explore the potential association of NAFLD with kidney function. Results: NAFLD was associated with impairment of kidney function. Multivariate-adjusted odds ratio illustrated that, compared to subjects with normal liver, NAFLD subjects had a significantly higher risk of MKFD with or without adjusted for blood glucose and other covariates (P = 0.041). Further results from multi-interaction analysis demonstrated that the underlying mechanisms linked NAFLD with im-paired kidney function may be that they share common risk factors and similar pathological proces-ses. Conclusions: The most striking finding of this study is that NAFLD is negatively associated with kidney function, in nondiabetic population. NAFLD and MKFD may share similar risk factors and/or pathological processes

    Recent advances of AI for engineering service and maintenance

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    An Adaptive Fuzzy Min-Max Neural Network Classifier Based on Principle Component Analysis and Adaptive Genetic Algorithm

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    A novel adaptive fuzzy min-max neural network classifier called AFMN is proposed in this paper. Combined with principle component analysis and adaptive genetic algorithm, this integrated system can serve as a supervised and real-time classification technique. Considering the loophole in the expansion-contraction process of FMNN and GFMN and the overcomplex network architecture of FMCN, AFMN maintains the simple architecture of FMNN for fast learning and testing while rewriting the membership function, the expansion and contraction rules for hyperbox generation to solve the confusion problems in the hyperbox overlap region. Meanwhile, principle component analysis is adopted to finish dataset dimensionality reduction for increasing learning efficiency. After training, the confidence coefficient of each hyperbox is calculated based on the distribution of samples. During classifying procedure, utilizing adaptive genetic algorithm to complete parameter optimization for AFMN can also fasten the entire procedure than traversal method. For conditions where training samples are insufficient, data core weight updating is indispensible to enhance the robustness of classifier and the modified membership function can adjust itself according to the input varieties. The paper demonstrates the performance of AFMN through substantial examples in terms of classification accuracy and operating speed by comparing it with FMNN, GFMN, and FMCN

    Nonalcoholic fatty liver associated with impairment of kidney function in nondiabetes population

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    Background: Nonalcoholic fatty liver disease (NAFLD) is associated with the increased burden of kidney. However, there is still no large population study to explore the potential relationship between NAFLD and mild kidney function damage (MKFD) after adjusted for confounding factors. This study is to test the hypothesis that NAFLD is associated with MKFD under controlling the effects of confoun-ding factors. Materials and methods: Levels of serum fasting glucose, creatinine, cholesterol, triglyceride, alanine aminotransferase and aspartate aminotransferase were analyzed from 1412 Chinese Han adults. Questionnaire and physical examination were performed to explore the potential association of NAFLD with kidney function. Results: NAFLD was associated with impairment of kidney function. Multivariate-adjusted odds ratio illustrated that, compared to subjects with normal liver, NAFLD subjects had a significantly higher risk of MKFD with or without adjusted for blood glucose and other covariates (P = 0.041). Further results from multi-interaction analysis demonstrated that the underlying mechanisms linked NAFLD with im-paired kidney function may be that they share common risk factors and similar pathological proces-ses. Conclusions: The most striking finding of this study is that NAFLD is negatively associated with kidney function, in nondiabetic population. NAFLD and MKFD may share similar risk factors and/or pathological processes

    MicroRNA Expression Profiling Screen miR-3557/324-targeted CaMK/mTOR in the Rat Striatum of Parkinson\u27s Disease in Regular Aerobic Exercise

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    This study aimed to screen the target miRNAs and to investigate the differential miR-3557/324-targeted signal mechanisms in the ratsā€™ model of Parkinsonā€™s disease (PD) with regular aerobic exercise. Rats were divided into sedentary control PD group (SED-PD, n = 18) and aerobic exercise PD group (EX-PD, n = 22). After 8 weeks of regular aerobic exercise, a 6-hydroxydopamine- (6-OHDA-) induced PD lesion model was constructed. Preregular aerobic exercises enhanced the injury resistance of rats with 6-OHDA-induced PD. The rotational behavior after injection of apomorphine hydrochloride was alleviated. Under the scanning electron microscopy, we found the neurons, axons, and villi of the striatum were clearly and tightly arranged, and neurons and axons significantly becoming larger. Tyrosine hydroxylase (TH) was increased significantly and Ī±-synuclein protein expression was reduced in the EX-PD group compared to the SED-PD group. Screening from miRNA microarray chip, we further found upregulation of miR-3557 and downregulation of miR-324 were closely related to the calcium-modulating signaling pathway, remitting the progress of Parkinsonā€™s disease on aerobic exercise. Compared to the SED-PD group, Ca2+/calmodulin dependent protein kinase II (CaMK2Ī±) was upregulated, but CaMKV and voltage-dependent anion-selective channel protein 1 (Vdac1) were significantly downregulated in the EX-PD group. Additionally, phosphatidylinositol-3-kinase (PI3K)/mammalian target of rapamycin (mTOR) expression were activated, and ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) expression was upregulated in the EX-PD group. Conclusions: the adaptive mechanism of regular aerobic exercise delaying neurodegenerative diseases and lesions was that miR-3557/324 was activated to regulate one of its targets CaMKs signaling pathways. CaMKs, coordinated with mTOR pathway-related gene expression, improved UCH-L1 level to favor for delaying neurodegeneration or improving the pathogenesis of PD lesions

    Suggestions on the development strategy of shale gas in China

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    AbstractFrom the aspects of shale gas resource condition, main exploration and development progress, important breakthrough in key technologies and equipment, this paper systematically summarized and analyzed current situation of shale gas development in China and pointed out five big challenges such as misunderstandings, lower implementation degree and higher economic uncertainty of shale gas resource, and still no breakthrough in exploration and development core technologies and equipment for shale gas buried depth more than 3500Ā m, higher cost and other non-technical factors that restrict the development pace. Aiming at the above challenges, we put forward five suggestions to promote the shale gas development in China: (1) Make strategies and set goals according to our national conditions and exploration and development stages. That is, make sure to realize shale gas annual production of 20Ā Ć—Ā 109Ā m3, and strives to reach 30Ā Ć—Ā 109Ā m3. (2) Attach importance to the research of accumulation and enrichment geological theory and exploration & development key engineering technologies for lower production and lower pressure marine shale gas reservoir, and at the same time orderly promote the construction of non-marine shale gas exploration & development demonstration areas. (3) The government should introduce further policies and set special innovation funds to support the companies to carry out research and development of related technologies and equipment, especially to strengthen the research and development of technology, equipment and process for shale gas bellow 3500Ā m in order to achieve breakthrough in deep shale gas. (4) Continue to promote the geological theory, innovation in technology and management, and strengthen cost control on drilling, fracturing and the whole process in order to realize efficient, economic and scale development of China's shale gas. (5) Reform the mining rights management system, establish information platform of shale gas exploration and development data, and correctly guide the non-oil and gas companies to participate in shale gas exploration and development

    Machine Learning Models for Multiparametric Glioma Grading With Quantitative Result Interpretations

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    Gliomas are the most common primary malignant brain tumors in adults. Accurate grading is crucial as therapeutic strategies are often disparate for different grades and may influence patient prognosis. This study aims to provide an automated glioma grading platform on the basis of machine learning models. In this paper, we investigate contributions of multi-parameters from multimodal data including imaging parameters or features from the Whole Slide images (WSI) and the proliferation marker Ki-67 for automated brain tumor grading. For each WSI, we extract both visual parameters such as morphology parameters and sub-visual parameters including first-order and second-order features. On the basis of machine learning models, our platform classifies gliomas into grades II, III, and IV. Furthermore, we quantitatively interpret and reveal the important parameters contributing to grading with the Local Interpretable Model-Agnostic Explanations (LIME) algorithm. The quantitative analysis and explanation may assist clinicians to better understand the disease and accordingly to choose optimal treatments for improving clinical outcomes. The performance of our grading model was evaluated with cross-validation, which randomly divided the patients into non-overlapping training and testing sets and repeatedly validated the model on the different testing sets. The primary results indicated that this modular platform approach achieved the highest grading accuracy of 0.90 Ā± 0.04 with support vector machine (SVM) algorithm, with grading accuracies of 0.91 Ā± 0.08, 0.90 Ā± 0.08, and 0.90 Ā± 0.07 for grade II, III, and IV gliomas, respectively
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