966-45 QT Dispersion in Essential Hypertension

Increased QT dispersion (QTd) reflects regional variation in ventricular repolarisation, and has been shown in heart failure and hypertrophic cardiomyopathy to relate to an increased incidence of sudden death. As essential hypertensives (EH) are also at increased risk of sudden death we aimed to determine whether increased QTd is found in those EH who are known to be at the highest risk of sudden death. In 50 EH we measured QTd (maximum corrected QT interval minus minimum corrected QT interval), echocardiographic left ventricular mass index (LVMI) (n=46 as 4 patients non-echogenic), office systolic and diastolic blood pressure (SSP, DSP), and 24 hour ambulatory systolic and diastolic blood pressure (24 SSP, 24 DSP) (n=40). Univariate analysis demonstrated no relationship between QTd and age, sex, height, weight, 24 SSP or 24 DBP. Significant relationships existed between QTd and LVMI (R2=0.25, P<0.001), SSP (R2=0.16, P<0.01), DSP (R2=0.08, P<0.05). Multiple linear regression analysis revealed the only relationships to QTd were LVMI (p<0.01) and SSP (p<0.05). Excluding 4 patients with electro-cardiographic left ventricular hypertrophy (ECG-LVH) from the analysis a significant relationship between QTd and LVMI (R2=0.13, P<0.05) and SSP (R2=0.10, P<0.05) persists. These demonstrate that increased QTd is found in EH with the highest risk of sudden death (greatest SSP and LVMI). This relationship persists in the absence of ECG-LVH. Further study of QTd, as a predictor of sudden death in EH is warranted

Adsorption of 4-Nitrophenol onto Iron Oxide Bentonite Nanocomposite: Process Optimization, Kinetics, Isotherms and Mechanism

Despite its importance in chemical industry, 4-Nitrophenol (4-NP) is a persistent organic pollutant that has serious effects on the ecosystem. In the present study, Box–Behnken design in response surface methodology was used to optimize the adsorption process parameters for the maximum 4-NP removal at 30 ℃ using Fe3O4/Bt NC. The regression model results suggested that the optimum adsorbent dosage, initial concentration, pH and contact time were 0.3182 g, 85 mg/L, 11 and 137.2 min, respectively. The regression model showed an optimum removal of 100%, while 99.5% removal was obtained from batch experiments at the optimum conditions suggested by the regression model, which confirm the model validity. The adsorption data best fitted to Freundlich isotherm model and Pseudo second-order kinetic model suggesting the existence of physical and chemical interaction between the fabricated composite and 4-NP. FTIR analysis suggested that the adsorption mechanism included an electrostatic attraction and the formation of new chemical bonds. Obtained results suggest that Fe3O4/Bt NC can be an effective adsorbent for complete 4-NP removal at the indicated optimum conditions.This research was made possible by an NPRP Grant # 10-0127-170270 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors. The author Dina Ewis acknowledged the financial support of QNRF through the Graduate Sponsorship Research Award (GSRA) number GSRA#6-2-0516-19029.Scopu

Effective Heterogeneous Fenton-Like degradation of Malachite Green Dye Using the Core-Shell Fe3O4@SiO2 Nano-Catalyst

In this study, the application of the core-shell Fe3O4@SiO2 nano-catalysts for fenton-like degradation of malachite green dye has been presented. The nano-catalysts were prepared using a combination of solvothermal and sol-gel techniques and characterized using XRD, FTIR, SEM/EDX, TEM and VSM techniques. The effects of various reaction parameters on the degradation of malachite green dye using the prepared nano-catalysts were investigated. The optimal condition for pH, catalyst dosage and H2O2 amount were found to be at 6.7, 15 mg and 50 μL, respectively. Under the optimized conditions, a degradation efficiency of 96.18 % for malachite green dye was achieved using the catalyst within 30 minutes at 303 K with a pseudo first order rate constant of 0.1102 min−1. The plausible mechanism for MG degradation was determined to be the combination of adsorption and simultaneous decomposition via formation of hydroxyl radicals. The performance of the nano-catalyst was compared with other fenton-like catalysts reported in the literature. Finally, the magnetic properties of the Fe3O4@SiO2 catalysts was utilized for its successful recovery and application in multiple degradation cycles.This research was made possible by an NPRP Grant#10-0127-170270 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors. The authors would like to acknowledge the help Centre for Advanced Materials (CAM) at Qatar University and Mr. Abdullah Al Ashraf for providing XRD test data. SEM/EDX tests was accomplished in the Central Laboratories unit, Qatar University.Scopu

Accelerating the Transition to a Circular Economy for Net-Zero Emissions by 2050: A Systematic Review

Achieving net-zero emissions by 2050 will require tackling both energy-related and non-energy-related GHG emissions, which can be achieved through the transition to a circular economy (CE). The focus of climate change crisis reversal has been on the energy-related continuum over the years through promoting renewable energy uptake and efficiency in energy use. Clean energy transition and efficiency gains in energy use alone will not be sufficient to achieve net-zero emissions in 2050 without paying attention to non-energy-related CO2 emissions. This study systematically reviews the CE literature across different themes, sectors, approaches, and tools to identify accelerators in transitioning to a CE. The study aims to understand and explore how technology, finance, ecosystem, and behavioral studies in the CE paradigm can be integrated as a decision-making tool for CE transition. The material analysis was carried out by identifying the main characteristics of the literature on CE implementation in the agriculture, industry, energy, water, and tourism sectors. Results of the literature survey are synthesized to engender clarity in the literature and identify research gaps to inform future research. Findings show that many studies focused on technology as an accelerator for CE transition, and more studies are needed regarding the CE ecosystem, financing, and behavioral aspects. Also, results show that CE principles are applied at the micro-, meso-, and macro- (national, regional, and global) levels across sectors with the dominance of the industrial sector. The agriculture, water, and energy sectors are at the initial stages of implementation. Additionally, the use of carbon capture and utilization or storage, conceptualized as a circular carbon economy, needs attention in tackling CE implementation in the energy sector, especially in hydrocarbon-endowed economies. The major implication of these findings is that for CE to contribute to accelerated net-zero emission by 2050, coordinated policies should be promoted to influence the amount of financing available to innovative circular businesses and technologies within an ecosystem that engenders behavioral change towards circularity

Effective Heterogeneous Fenton‐Like degradation of Malachite Green Dye Using the Core‐Shell Fe 3

In this study, the application of the core-shell Fe3O4@SiO2 nano-catalysts for fenton-like degradation of malachite green dye has been presented. The nano-catalysts were prepared using a combination of solvothermal and sol-gel techniques and characterized using XRD, FTIR, SEM/EDX, TEM and VSM techniques. The effects of various reaction parameters on the degradation of malachite green dye using the prepared nano-catalysts were investigated. The optimal condition for pH, catalyst dosage and H2O2 amount were found to be at 6.7, 15 mg and 50 μL, respectively. Under the optimized conditions, a degradation efficiency of 96.18 % for malachite green dye was achieved using the catalyst within 30 minutes at 303 K with a pseudo first order rate constant of 0.1102 min−1. The plausible mechanism for MG degradation was determined to be the combination of adsorption and simultaneous decomposition via formation of hydroxyl radicals. The performance of the nano-catalyst was compared with other fenton-like catalysts reported in the literature. Finally, the magnetic properties of the Fe3O4@SiO2 catalysts was utilized for its successful recovery and application in multiple degradation cycles.This research was made possible by an NPRP Grant#10-0127-170270 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors. The authors would like to acknowledge the help Centre for Advanced Materials (CAM) at Qatar University and Mr. Abdullah Al Ashraf for providing XRD test data. SEM/EDX tests was accomplished in the Central Laboratories unit, Qatar University.Scopu

Adsorption of organic pollutants by nanomaterial-based adsorbents: An overview

Nanomaterial-based adsorbents have garnered increasing attention in water and wastewaters treatment applications due to their attractive properties and strong adsorption capabilities for various organic compounds. The current review appraises the use of nanomaterial adsorbents (NAs); namely: carbon nanotubes (CNTs), graphene sheets (GS), and metal oxides (MO) for environmental remediation applications. The adsorption capacities for organic dyes, aromatic compounds, phenolic derivatives, pharmaceuticals, and antibiotics are comprehensively reviewed. The current study critically investigates the role of physicochemical properties of the adsorbents, solution chemistry of the adsorbates, and the uptake mechanism on the sorption performance of NAs. The adsorption isotherms reveal Langmuir and Freundlich models to be the best fit of the experimental data in most of the studies, whilst the adsorption kinetics is well described by the pseudo-second-order model. This review attempts to present a prior knowledge about the adsorption capability of CNTs, GS, and MO for the removal of organic pollutants (OPs) from wastewaters by assessing outcomes of peer-reviewed articles published between 2000 and 2019.This research was made possible by an NPRP Grant # 10-0127-170270 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors.Scopu

Synthesis and Characterization of Fe3O4 Nanoparticles Using Different Experimental Methods

This paper reports a comparative study on the synthesis of Fe3O4 nanoparticles using three different methods, namely; Co-precipitation, Sonochemical and Solvothermal methods. Ferric chloride hexahydrate (FeCl3.6H2O) and Ferrous chloride tetrahydrate (FeCl2.4H2O) were used as the iron precursor for the Co-precipitation method; while, Ferrous sulphate Heptahydrate (FeCl2.7H2O) and Ferric chloride hexahydrate (FeCl3.6H2O) were used as the iron precursor for sonochemical and solvothermal synthesis methods, respectively. The effect of the experimental methods and the precursors used on the shape and size of the Fe3O4 nanoparticles were investigated using different characterization techniques. The chemical characterization of the samples were carried out using EDX. The size of the nanoparticles were determined using particle size analyzer. The SEM and TEM images were used study to the surface morphology of the produced nanoparticles. Finally, TGA was used to study the thermal stability of the prepared iron oxide nanoparticles.This research was made possible by an NPRP Grant # 10-0127-170270 from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of the authors. The authors would like to thank the Core Labs, QEERI for their SEM and TEM imaging.Scopu