Influence of fly ash and steam on microstructure, and mechanical properties of oxide bonded porous SiC ceramics

Ceramic filters specially SiC filters are used in advanced coal combustion and gasification processes to remove fine dust particles from the fuel gas at high temperatures and high pressure for protection of turbine blades and other downstream components from corrosion and erosion and to meet the environmental regulations. Processing of corrosion resistant porous SiC ceramics at low temperature using a simple technique is still challenging. In this study oxide bonded porous SiC ceramics were synthesized by cost effective method. The corrosion behaviour of SiC ceramic filter materials in presence of steam, coal ash and both coal ash and steam was investigated at 1000 degrees C for 96-240 h. The apparent changes in mass, porosity and density with corrosion duration and environment were recorded. Finally SEM, XRD and mechanical tests of the corroded samples were carried out. The corrosion test results indicated water vapour is the perpetrator for strength degradation. (C) 2019 SECV. Published by Elsevier Espana, S.L.U

Quantum yield of Cl<SUP>&#8727;</SUP> (<SUP>2</SUP>P<SUB>&#189;</SUB>) production in the gas phase photolysis of CCl<SUB>4</SUB> in the ultraviolet

In this paper, we have probed the dynamics of chlorine atom production from the gas phase photodissociation of carbon tetrachloride at 222 and 235 nm. The quantum yield, &#966;&#8727; of Cl&#8727; (2P&#189;) production has been determined by probing the nascent concentrations of both excited (2P&#189;) and ground state (2P3/2) chlorine atoms by suitable resonance-enhanced multiphoton ionization (REMPI) detection schemes. Although at the photolysis wavelengths the absorption of carbon tetrachloride is weak, significant amounts of Cl&#8727; are produced. Surprisingly, the quantum yield of Cl&#8727; production does not follow the absorption spectrum closely, which gives rise to the possibility of an indirect dissociation mechanism present in CCl4 along with direct dissociation at these ultraviolet wavelengths

The Role of NF-κB and H3K27me3 Demethylase, Jmjd3, on the Anthrax Lethal Toxin Tolerance of RAW 264.7 Cells

BACKGROUND: In Bacillus anthracis, lethal toxin (LeTx) is a critical virulence factor that causes immune suppression and toxic shock in the infected host. NF-kappaB is a key mediator of the inflammatory response and is crucial for the plasticity of first level immune cells such as macrophages, monocytes and neutrophils. In macrophages, this inflammatory response, mediated by NF-kappaB, can regulate host defense against invading pathogens. A Jumonji C family histone 3 lysine-27 (H3K27) demethylase, Jmjd3, plays a crucial role in macrophage plasticity and inflammation. Here we report that NF-kappaB and Jmjd3 can modulate the LeTx intoxication resistance of RAW 264.7 cells. PRINCIPAL FINDINGS: This study showed that a 2 h exposure of macrophages to LeTx caused substantial cell death with a survival rate of around 40%. The expression of the Jmjd3 gene was induced 8-fold in intoxication-resistant cells generated by treatment with lipopolysaccharides of RAW 264.7 cells. These intoxication-resistant cell lines (PLx intox and PLxL intox) were maintained for 8 passages and had a survival rate of around 100% on secondary exposure to LeTx and lipopolysaccharides. Analysis of NF-kappaB gene expression showed that the expression of p100, p50 and p65 was induced around 20, 7 and 4 fold, respectively, in both of the intoxication-resistant cell lines following a 2 h treatment with PLxL (0.1+0.1+1 microg/ml). In contrast, these NF-kappaB genes were not induced following treatment with PLx treatment at the same concentrations. CONCLUSIONS: Although LeTx influences macrophage physiology and causes defects of some key signaling pathways such as GSK3beta which contributes to cytotoxicity, these results indicate that modulation of NF-kappaB by p50, p100 and Jmjd3 could be vital for the recovery of murine macrophages from exposure to the anthrax lethal toxin

Metal-assisted red light-induced efficient DNA cleavage by dipyridoquinoxaline-copper(II) complex

Complete cleavage of double stranded pUC19 DNA by the complex [Cu(dpq)2(H2O)](ClO4)2 (dpq, dipyridoquinoxaline) has been observed on irradiation at 694 nm from a pulsed ruby laser, assisted by the metal d-band transition as well as the quinoxaline triplet states in the absence of any external additives

Correlation of serum aspartate aminotransferase level to platelet count ratio index with non-alcoholic fatty liver disease activity score

In case of non-alcoholic fatty liver disease, the ratio of serum aspartate&nbsp; aminotransferase (AST) level to platelet count index has been proposed as a non-invasive and readily available tool for the assessment of non-alcoholic steatohepatitis. The study was conducted on 50&nbsp; non-alcoholic fatty liver disease patient (25&nbsp; non-alcoholic steatohepatitis and 25 simple steatosis). The mean (± SD) serum AST level in the non-alcoholic steatohepatitis group&nbsp; was 55.2 ± 30.1 IU/L whereas in simple steatosis group it was 33.6 ± 20.0 IU/L. The mean platelet count in the non-alcoholic steatohepatitis group was 303.1 ± 68.7 x 109 /L whereas in the simple steatosis group it was 327.8 ± 66.8 x 109/L. The mean AST platelet ratio index (APRI) score in non-alcoholic steatohepatitis group was 0.5 ± 0.3 and in the simple steatosis group it was 0.3 ± 0.2. In conclusion, the APRI&nbsp; was&nbsp; significantly higher in the non-alcoholic steatohepatitis group than the simple steatosis group

Simultaneous analysis of frequency and voltage control of the interconnected hybrid power system in presence of FACTS devices and demand response scheme

This work confers the simultaneous analysis of voltage and frequency control of the 3-area interconnected hybrid power system (IHPS) consisting of parabolic-trough solar power system (PSP), wind power system (WPS) and dish-stirling solar power system (DSP) under the paradigm of microgrid. The speculated result of the IHPS is presented and analyzed considering real and reactive power as the function of both voltage and frequency. 9The proposed IHPS under investigation has been mathematically modeled for direct coupling like active power-frequency and reactive power-voltage relationships and cross coupling like active power-voltage and reactive power-frequency? relationships. The system responses under different operating conditions have been investigated to see the cross-coupling behavior of the proposed IHPS in the presence of voltage compensating devices like dynamic voltage restorer (DVR) and Static Synchronous Compensator (STATCOM). Further, Demand Response Scheme (DRS) as a frequency control strategy has been considered to enhance the system stability. System responses have been critically analyzed under Mine Blast Algorithm (MBA) based proportional-integral-derivative (PID) controllersThis work was made possible by NPRP grant # [ 13S-0108-20008 ] from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors".Scopu

Prevalence of chronic cough, its risk factors and population attributable risk in the Burden of Obstructive Lung Disease (BOLD) study: a multinational cross-sectional study

© 2024 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)Background: Chronic cough is a common respiratory symptom with an impact on daily activities and quality of life. Global prevalence data are scarce and derive mainly from European and Asian countries and studies with outcomes other than chronic cough. In this study, we aimed to estimate the prevalence of chronic cough across a large number of study sites as well as to identify its main risk factors using a standardised protocol and definition. Methods: We analysed cross-sectional data from 33,983 adults (≥40 years), recruited between Jan 2, 2003 and Dec 26, 2016, in 41 sites (34 countries) from the Burden of Obstructive Lung Disease (BOLD) study. We estimated the prevalence of chronic cough for each site accounting for sampling design. To identify risk factors, we conducted multivariable logistic regression analysis within each site and then pooled estimates using random-effects meta-analysis. We also calculated the population attributable risk (PAR) associated with each of the identifed risk factors. Findings: The prevalence of chronic cough varied from 3% in India (rural Pune) to 24% in the United States of America (Lexington,KY). Chronic cough was more common among females, both current and passive smokers, those working in a dusty job, those with a history of tuberculosis, those who were obese, those with a low level of education and those with hypertension or airflow limitation. The most influential risk factors were current smoking and working in a dusty job. Interpretation: Our findings suggested that the prevalence of chronic cough varies widely across sites in different world regions. Cigarette smoking and exposure to dust in the workplace are its major risk factors.info:eu-repo/semantics/publishedVersio

Association of respiratory symptoms and lung function with occupation in the multinational Burden of Obstructive Lung Disease (BOLD) study

Background Chronic obstructive pulmonary disease has been associated with exposures in the workplace. We aimed to assess the association of respiratory symptoms and lung function with occupation in the Burden of Obstructive Lung Disease study. Methods We analysed cross-sectional data from 28 823 adults (≥40 years) in 34 countries. We considered 11 occupations and grouped them by likelihood of exposure to organic dusts, inorganic dusts and fumes. The association of chronic cough, chronic phlegm, wheeze, dyspnoea, forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1)/FVC with occupation was assessed, per study site, using multivariable regression. These estimates were then meta-analysed. Sensitivity analyses explored differences between sexes and gross national income. Results Overall, working in settings with potentially high exposure to dusts or fumes was associated with respiratory symptoms but not lung function differences. The most common occupation was farming. Compared to people not working in any of the 11 considered occupations, those who were farmers for ≥20 years were more likely to have chronic cough (OR 1.52, 95% CI 1.19–1.94), wheeze (OR 1.37, 95% CI 1.16–1.63) and dyspnoea (OR 1.83, 95% CI 1.53–2.20), but not lower FVC (β=0.02 L, 95% CI −0.02–0.06 L) or lower FEV1/FVC (β=0.04%, 95% CI −0.49–0.58%). Some findings differed by sex and gross national income. Conclusion At a population level, the occupational exposures considered in this study do not appear to be major determinants of differences in lung function, although they are associated with more respiratory symptoms. Because not all work settings were included in this study, respiratory surveillance should still be encouraged among high-risk dusty and fume job workers, especially in low- and middle-income countries.publishedVersio