Novel functionalized fillers for mixed matrix membranes for C02/CH4 separation

Il y a des réservoirs de gaz naturel à travers le monde qui ne sont pas exploités en raison de leur haute teneur en C0₂. Il serait donc intéressant que la technologie soit améliorée pbur la purification du gaz naturel. La grande majorité des systèmes commerciaux de séparation des gaz par membrane utilise des polymères en raison de leur compacité, leur facilité d'utilisation et de leur coût. Cependant, les membranes polymériques conçues pour des séparations de gaz sont reconnues pour avoir un compromis entre la perméabilité et la sélectivité représenté par les courbes limites supérieures de Robeson. La recherche pour les matériaux membraines qui transcendent la limite supérieure de Robeson a été une question critique dans la recherche axée sur les membranes pour la séparation de gaz durant la dernière décennie. Ainsi, de nombreux chercheurs ont exploré l'idée de membranes à matrice mixte (MMM) pour surmonter ces limitations. Ces membranes combinent une matrice polymère avec un tamis moléculaire inorganique tel que les zéolithes. Ce travail présente une étude de la synthèse et de la caractérisation de nouvelles charges pouvant être utilisées dans les membranes à matrice mixte (MMM) pour la séparation du C0₂/CH₄. En première partie de cette thèse, nous avons développé une stratégie pour surmonter les approches précédentes qui sont problématiques pour greffer les charges zéolithes. Nous avons synthétisé et caractérisé la zéolithe FAU/EMT et étudié les effets de la polarité du solvant et de la nature des aminosilanes sur les propriétés physico-chimiques des charges, ainsi que sur les propriétés d'adsorption du C0₂. Après cela, avec l'aide d'un plan expérimental de Taguchi, nous avons optimisé les paramètres de la réaction de greffage de la zéolithe FAU/EMT avec l'agent 3-aminopropylméthyldiéthoxysilane (APMDES) pour préparer de bons remplissages greffés pour une utilisation dans les MMM. Par la suit, les charges préparées dans les conditions optimisées, sont greffées et incorporées dans une matrice de polyimide pour fabriquer des MMM pour la séparation du C0₂/CH₄. Les résultats obtenus ont montré qu'à 25 % (m/m), les charges greffées et imprégnées sur le polymère augmentaient à la fois la perméabilité et la sélectivité par rapport à des membrane de polyimide seul. Lors de la deuxième partie de ma thèse, nous avons développé la préparation, la caractérisation et les propriétés de séparation des gaz de C0₂/CH₄ de MMM comportant différents MOF et le polyimide 6FDA-ODA afin d'étudier l'effet de la fonctionnalisation par le ligand (-NH₂) sur la performance de séparation du C0₂/CH₄ par les MMM. Pour la première fois, nous avons choisi de nouveaux MOF à base de Zr (UiO-66, NH₂-UIO-66, UiO-67), ainsi que MOF-199 (HKUST-1) avec un ligand mixte fonctionnalisé (NH₂-MOF-199) basés sur des calculs de simulation pour la séparation de C0₂/CH₄ à partir des résultats expérimentaux rapportés précédemment. Les résultats obtenus ont montré une augmentation de la sélectivité pour la MMM sauf pour le remplissage avec UiO-67. La présence de groupes fonctionnels d'aminés dans le NH₂-UIO-66 a augmenté à la fois la sélectivité et la perméabilité du C0₂. D'autre part, une MMM faite avec UiO-66 a augmenté de manière significative la perméabilité du C0₂ par rapport à la membrane 6FDA-polyimide seul sans aucune perte de la sélectivité idéale

THE RELATIONSHIP BETWEEN EFL LEARNERS' ATTITUDE, SELF–EFFICACY AND THEIR WRITING ACHIEVEMENT

Writing ability as one of the most important aspect of language learning plays an important role in pedagogical settings. The present study attempted to investigate the relationships between writing skill and students’ personal attributes namely self-efficacy and attitude. To this purpose, 70 students were selected and participated in this study. The results of data analysis showed that both self-efficacy and attitude have positive correlations with writing ability and there were significant differences between those who have high self-efficacy and those who have low self-efficacy. Finally, the pedagogical implications of findings have been discussed.  Article visualizations

Rare Complications of Two Most Common Nerve Blocks: Posterior Superior Alveolar and Inferior Alveolar Nerve Block: A Mini Review

Administration of local anesthetic agents is a safe procedure. However, various localized, distant and systemic complications have been reported. Posterior superior alveolar nerve block (PSAB) and inferior alveolar nerve block (IANB) are the two most common nerve blocks in the jaws. In this mini review, we tend to describe rare complications of these two methods. Rare complications of IANB includenecrosis of the chin skin of, neuritis of the facial nerve, trismus, ischemia and blanching of skin, anemia in the face, numbness of the ear, diplopia , taste disturbance, infra condylar abscess, burning sensation in eye, reduction in visual acuity and atrophy of the optic nerve. Some Rare complications of PSA are diplopia, amaurosis, epiphoria, paralysis, esotropia, hematoma, pupillary dilation and ptosis, paresis of the lateral pterygoid muscle and trismus. Since complications of dental anesthesia are inevitable, their prevention and management are essential. Management of complications requires comprehensive knowledge regarding the management of complications and injection techniques to prevent these complication

Optimization of the electrocoagulation process for sulfate removal using response surface methodology

Sulfate concentrations affected on the natural sulfur cycle in the anaerobic treatment, therefore pretreatment of wastewater containing sulfate must be considered. In this work electrocoagulation techniques have considered as an effective and environmentally friendly process for desulfurization from wastewater. Three factors including initial pH, initial sulfate concentration and current density were selected as the effective factors and were optimized using response surface methodology. An initial pH of 8, initial sulfate concentration of80mg/l and current density of12mA/cm(2)were determined to be optimum values by the statistical models. The maximum sulfate removal and minimum sludge generation under optimal conditions were 68.5% and 0.075g, respectively. The kinetics of sulfate removal study investigated the pseudo-first models were better described experimental data and was selected as overall kinetic removal of sulfate

The global burden of cancer attributable to risk factors, 2010-19 : a systematic analysis for the Global Burden of Disease Study 2019

Background Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. Methods The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk-outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. Findings Globally, in 2019, the risk factors included in this analysis accounted for 4.45 million (95% uncertainty interval 4.01-4.94) deaths and 105 million (95.0-116) DALYs for both sexes combined, representing 44.4% (41.3-48.4) of all cancer deaths and 42.0% (39.1-45.6) of all DALYs. There were 2.88 million (2.60-3.18) risk-attributable cancer deaths in males (50.6% [47.8-54.1] of all male cancer deaths) and 1.58 million (1.36-1.84) risk-attributable cancer deaths in females (36.3% [32.5-41.3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20.4% (12.6-28.4) and DALYs by 16.8% (8.8-25.0), with the greatest percentage increase in metabolic risks (34.7% [27.9-42.8] and 33.3% [25.8-42.0]). Interpretation The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.Peer reviewe

The effect of adding hyoscine to vaginal misoprostol on shortening the time of abortion induction

Induced abortion is the termination of pregnancy by medical or surgical methods before the fetus’ viability. Available evidences show that due to spasmolytic effects, use of Hyoscine with Misoprostol may reduce the pain during abortion induction. The aim of this study is to evaluate the effect of Misoprostol in combination with Hyoscine compared with Misoprostol alone in reducing the duration of abortion induction. In a clinical trial at the Department of Obstetrics and Gynecology, Qazvin University of Medical Sciences on 126 pregnant women with gestational age below 20 weeks elected for abortion, the effect of Misoprostol in combination with Hyoscine compared with Misoprostol alone was evaluated in reducing the duration of abortion induction. The mean duration of abortion induction in Misoprostol with Hyoscine represented statistically significant decrease compared with Misoprostol (653.38 ± 80.386 min, with 726.29 ± 64.56 min) (P ≤ 0.001). There was no significant difference in demographic characteristics, including maternal age, gestational age, gravidity, parity and history of abortion between the two study groups, and the two groups were homogeneous. Duration of abortion induction (p < 0.001), the rate of vaginal bleeding (p < 0.001), and the rate of hemoglobin deficiency (p = 0.002) in the group receiving Misoprostol suppositories and Hyoscine was significantly lower than in the group receiving Misoprostol suppositories alone. The need for analgesics in the group receiving Misoprostol suppositories and Hyoscine was significantly less than in the group receiving Misoprostol suppositories alone (p < 0.001). Finally, results of this study showed that adding 20 mg Hyoscine intra venous to vaginal Misoprostol is effective in significantly reducing the duration of the abortion induction, getting less pain killers, less vaginal bleeding and less decrease in hemoglobin changes

Reducing the Effect of the Endmembers’ Spectral Variability by Selecting the Optimal Spectral Bands

Variable environmental conditions cause different spectral responses of scene endmembers. Ignoring these variations affects the accuracy of fractional abundances obtained from linear spectral unmixing. On the other hand, the correlation between the bands of hyperspectral data is not considered by conventional methods developed for dealing with spectral variability. In this paper, a novel approach is proposed to simultaneously mitigate spectral variability and reduce correlation among different endmembers in hyperspectral datasets. The idea of the proposed method is to utilize the angular discrepancy of bands in the Prototype Space (PS), which is constructed using the endmembers of the image. Using the concepts of PS, in which each band is treated as a space point, we proposed a method to identify independent bands according to their angles. The proposed method comprised two main steps. In the first step, which aims to alleviate the spectral variability issue, image bands are prioritized based on their standard deviations computed over some sets of endmembers. Independent bands are then recognized in the prototype space, employing the angles between the prioritized bands. Finally, the unmixing process is done using the selected bands. In addition, the paper presents a technique to form a spectral library of endmembers’ variability (sets of endmembers). The proposed method extracts endmembers sets directly from the image data via a modified version of unsupervised spatial–spectral preprocessing. The performance of the proposed method was evaluated by five simulated images and three real hyperspectral datasets. The experiments show that the proposed method—using both groups of spectral variability reduction methods and independent band selection methods—produces better results compared to the conventional methods of each group. The improvement in the performance of the proposed method is observed in terms of more appropriate bands being selected and more accurate fractional abundance values being estimated