570 research outputs found

    Thermal Effects for Shaft-Pre-Stress on Rotor Dynamic System

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    This Paper outlines study behaviour of rotating shaft with high speed under thermal effects. The method of obtaining the frequency response functions of a rotor system with study whirl effect in this revision the raw data obtained from the experimental results (using Smart Office program) are curve-fitted by theoretical data regenerated from some of the experimental data and simulating it using finite element (ANSYS 12). (FE) models using the Eigen analysis capability were used to simulate the vibration. The results were compared with experimental data show analysis data with acceptable accuracy and performance. The rotating effect causes un-symmetry in the system matrices, resulting in complexity in decoupling the mathematical models of the system for the purpose of modal analysis. Different method is therefore required, which can handle general system matrices rather than symmetrical matrices, which is normal for passive structures. Mathematical model of the system from the test data can be assembled. The frequency response functions are extracted, Campbell diagram are draw and simulated. (FE) is used to carry out such as simulation since it has good capability for Eigen analysis and also good graphical facility. Keywords: Thermal effects, Modelling, Campbell diagram, Whirl, Rotor dynamics.Comment: Published by: Academic Research Publishing Agency. All rights reserved, 6 pages, 4 figures, 1 pictur

    Pengaruh Kompensasi dan Disiplin Kerja terhadap Kinerja Karyawan pada PT. Pilar Kreasi Mandiri

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    This study aims to test and analyze the effect of compensation and work discipline on employee performance at PT. Pilar Kreasi Mandiri. The method of data collection in this study was by distributing questionnaires to 50 respondents of PT. Pilar Kreasi Mandiri. The method used is an associative quantitative method using primary data and secondary data. Data analysis techniques used are validity test, reliability test, classical assumption test, determination coefficient analysis (adjusted R2), multiple linear regression analysis, hypothesis testing using SPSS Version 20. The results show that compensation and work discipline have a positive and significant effect on employee performance. Based on the analysis of the determination coefficient, the R Square is 0.861 or 86.1%, while the remaining 13.9% is influenced by other variables that are not studied or observed

    Defect Diagnosis in Rotors Systems by Vibrations Data Collectors Using Trending Software

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    Vibration measurements have been used to reliably diagnose performance problems in machinery and related mechanical products. A vibration data collector can be used effectively to measure and analyze the machinery vibration content in gearboxes, engines, turbines, fans, compressors, pumps and bearings. Ideally, a machine will have little or no vibration, indicating that the rotating components are appropriately balanced, aligned, and well maintained. Quick analysis and assessment of the vibration content can lead to fault diagnosis and prognosis of a machine's ability to continue running. The aim of this research used vibration measurements to pinpoint mechanical defects such as (unbalance, misalignment, resonance, and part loosening), consequently diagnosis all necessary process for engineers and technicians who desire to understand the vibration that exists in structures and machines. Keywords- vibration data collectors; analysis software; rotating components.Comment: 11 pages,6 figures,1 pictuer,1 schem

    Cardiovascular medications and regulation of COVID-19 receptors expression

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    INTRODUCTION: Emerging epidemiological studies suggested that Renin–Angiotensin–Aldosterone system (RAAS) inhibitors may increase infectivity and severity of COVID-19 by modulating the expression of ACE2. METHODS: In silico analysis was conducted to compare the blood expression levels of SARS-CoV-2 entry genes between age and gender matched cohort of hypertensive patients versus control, and to determine the effect of common cardiovascular medications on the expression of COVID-19 receptors in vitro using primary human hepatocytes. RESULTS: The transcriptomic analysis revealed a significant increase of ACE2 and TMPRSS2 in the blood of patients with hypertension. Treatment of primary human hepatocytes with captopril, but not enalapril, significantly increased ACE2 expression. A similar pattern of ACE2 expression was found following the in vitro treatments of rat primary cells with captopril and enalapril. Telmisartan, a second class RAAS inhibitors, did not affect ACE2 levels. We have also tested other cardiovascular medications that may be used alone, or in combination with RAAS inhibitors. Some of these medications increased TMPRSS2, while others, like furosemide, significantly reduced COVID-19 receptors. CONCLUSIONS: The increase in ACE2 expression levels could be due to chronic use of RAAS inhibitors or alternatively caused by other hypertension-related factors or presence of other comorbidities. Treatment of common co-morbidities often require chronic use of multiple medications, which may result in an additive increase in the expression of ACE2 and TMPRSS2. Our data suggest that more research is needed to determine the effect of different medications, as well as medication combinations, on COVID-19 receptors

    Enhanced expression of immune checkpoint receptors during SARS-CoV-2 viral infection

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    The immune system is tightly regulated by the activity of stimulatory and inhibitory immune receptors. This immune homeostasis is usually disturbed during chronic viral infection. Using publicly available transcriptomic datasets, we conducted in silico analyses to evaluate the expression pattern of 38 selected immune inhibitory receptors (IRs) associated with different myeloid and lymphoid immune cells during coronavirus disease 2019 (COVID-19) infection. Our analyses revealed a pattern of overall upregulation of IR mRNA during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. A large number of IRs expressed on both lymphoid and myeloid cells were upregulated in nasopharyngeal swabs (NPSs), while lymphoid-associated IRs were specifically upregulated in autopsies, reflecting severe, terminal stage COVID-19 disease. Eight genes (BTLA, LAG3, FCGR2B, PDCD1, CEACAM1, CTLA4, CD72, and SIGLEC7), shared by NPSs and autopsies, were more expressed in autopsies and were directly correlated with viral levels. Single-cell data from blood and bronchoalveolar samples also reflected the observed association between IR upregulation and disease severity. Moreover, compared to SARS-CoV-1, influenza, and respiratory syncytial virus infections, the number and intensities of upregulated IRs were higher in SARS-CoV-2 infections. In conclusion, the immunopathology and severity of COVID-19 could be attributed to dysregulation of different immune inhibitors. Targeting one or more of these immune inhibitors could represent an effective therapeutic approach for the treatment of COVID-19 early and late immune dysregulations

    Immunohistochemical Assessment of TNFAIP3/A20 Expression Correlates With Early Tumorigenesis in Breast Cancer

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    BACKGROUND/AIM: Limited data exist on the expression pattern of TNFAIP3/A20, as assayed by immunohistochemistry (IHC), in breast cancer tissues. This study aimed to assess A20 expression pattern in breast cancer. Materials and Methods: The expression of A20 was analysed using IHC in 50 breast cancer cases retrieved from the Sharjah Breast Cancer Center at the University Hospital Sharjah, United Arab Emirates. Omics survival data were also used to analyse its association with survival in endocrine-treated subgroups. Results: A20 expression in breast cancer tissues was 'tumor-specific', and as compared to normal tissue areas, its expression was associated with both intensity and extent in early grade 1 (p<0.0001) in all molecular subtypes. In addition, using omics survival data from a cohort of 3,520 breast cancer patients, we showed that A20 overexpression associated with lower overall survival rate in the endocrine treated subgroups [hazard ratio (HR)=2.14, 95%CI=1.61-2.82, p<0.0001]. Conclusion: A20 can serve as a biomarker for early diagnosis of breast cancers

    Resilient safety anti-terrorism city terrorism as a new challenge in contemporary Iraqi city

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    Resilience against a variety of common and disruptive threats of terrorism is increasingly valuable in terms of the way communities are designed, operated and how urban practitioners are working to improve the community safety level. This is especially true of communities and cities, activities that are considered susceptible to terrorist attacks. This work explores a robust approach to create a safe climate, safety societies in ways that can decrease the likelihood and effect of a terrorist attack. In specific, the research problem was: The inability of our cities to face the Unpredictable challenges (terrorism attacks) with a resilient flexible strategies that’s contributed in reduces the urban safety. The research assumes: adoption of resilience strategy will contribute to increase the city safety against the Unpredictable challenges (terrorism attacks). The research aimed to: reach more resilient safety cities that can confront the Unpredictable challenges (terrorism attacks) through its community and built environment. The research methodology was: Explain the concepts of resilience, resilient cities and its characteristics and approaches, then adopt an integration approach to drop it on the characteristics of safety city as access to the indicators of resilient safety anti- terrorism city with Canada's experience anti-terrorism attacks as case study. The important conclusions were: There is necessity for professionals with a culture of terrorism to set up alerts and alarm the people before the risk entering. Resilience proxies depend on urban system type and its components that’s differs from place to another, one of the robust resilient city approaches was: integrated-forward looking approach it is not only react to emergent threats, however may draw trends to survive , take off the city systems

    Vitamin D enhances type I IFN signaling in COVID-19 patients

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    The ability of Vitamin D (VitD) to modulate antiviral responses through induction of antimicrobial peptide is well established. However, the effect of VitD on host responses to SARS-CoV-2 is not well investigated. We here report the ability of VitD to enhance host IFN-alpha/beta (a/β) signaling both in vitro and among severe COVID-19 patients treated with VitD. Blood and saliva specimens were obtained from severe COVID-19 patients treated (43 patients), or not (37 patients), with vitD, during their stay in intensive care unit. Patients were followed up to 29 days following admission, and patient survival outcomes were collected. Higher activity levels of RIG-1/MDA-5 and JAK-STAT signaling pathways were observed with significantly higher gene and protein levels of antiviral interferon stimulating genes (ISGs) such as MX-1 and ISG-15; both in vitro, following treatment of PBMCs with vitD, and in whole blood and saliva specimens of VitD treated patients. Moreover, VitD treated patients had lower risk of all-cause mortality by day 29 compared to untreated patients (adjusted hazard ratio, 0.37, 95% confidence interval of 0.14–0.94; P = 0.038). The herein uncovered regulatory role of VitD on type I IFNs suggests the importance of insuring a normal level of VitD for the prevention and probably treatment of SARS-CoV-2 infection. Additional mechanistic studies, however, are needed to fully elucidate the antiviral effects of VitD particularly in the setting of COVID-19 infection

    Thermal conduction simulation based on reconstruction digital rocks with respect to fractures

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    Effective thermal conductivity (ETC), as a necessary parameter in the thermal properties of rock, is affected by the pore structure and the thermal conduction conditions. To evaluate the effect of fractures and saturated fluids on sandstone’s thermal conductivity, we simulated thermal conduction along three orthogonal (X, Y, and Z) directions under air- and water-saturated conditions on reconstructed digital rocks with different fractures. The results show that the temperature distribution is separated by the fracture. The significant difference between the thermal conductivities of solid and fluid is the primary factor influencing the temperature distribution, and the thermal conduction mainly depends on the solid phase. A nonlinear reduction of ETC is observed with increasing fracture length and angle. Only when the values of the fracture length and angle are large, a negative effect of fracture aperture on the ETC is apparent. Based on the partial least squares (PLS) regression method, the fluid thermal conductivity shows the greatest positive influence on the ETC value. The fracture length and angle are two other factors significantly influencing the ETC, while the impact of fracture aperture may be ignored. We obtained a predictive equation of ETC which considers the related parameters of digital rocks, including the fracture length, fracture aperture, angle between the fracture and the heat flux direction, porosity, and the thermal conductivity of saturated fluid
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