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161.
In this study, for the first time, a hybrid continuum-atomistic based model is proposed for electrokinetics, electroosmosis and electrophoresis, through nanochannels. Although continuum based methods are accurate enough to model fluid flow and electric potential in nanofluidics (in dimensions larger than 4 nm), ionic concentration is too low in nanochannels for the continuum assumption to be valid. On the other hand, the non-continuum based approaches are too time-consuming and therefore is limited to simple geometries, in practice. Here, to propose an efficient hybrid continuum-atomistic method of modelling the electrokinetics in nanochannels; the fluid flow and electric potential are computed based on continuum hypothesis coupled with an atomistic Lagrangian approach for the ionic transport. The results of the model are compared to and validated by the results of the molecular dynamics technique for a couple of case studies. Then, the influences of bulk ionic concentration, external electric field, size of nanochannel, and surface electric charge on the electrokinetic flow and ionic mass transfer are investigated, carefully. The hybrid continuum-atomistic method is a promising approach to model more complicated geometries and investigate more details of the electrokinetics in nanofluidics. 相似文献
162.
Prof. Dr. Antonino Gulino Prof. Dr. Georgia Papanikolaou Prof. Dr. Paola Lanzafame Prof. Dr. Abdellatif Aaliti Prof. Dr. Patrizia Primerano Prof. Dr. Luca Spitaleri Prof. Dr. Claudia Triolo Zainab Dahrouch Amani Khaskhoussi Prof. Dr. Sandra Lo Schiavo 《ChemistryOpen》2021,10(10):1033-1040
We report on the facile synthesis of SiO2@nitrized-TiO2 nanocomposite (NST) by calcination of TiO2 xerogel with OctaAmmonium POSS® (N-POSS; POSS=polyhedral oligomeric silsesquioxanes). The as-obtained nanoporous mixed oxide is constituted by uniformly distributed SiO2 and nitrized-TiO2, where the silica component is present in an amorphous state and TiO2 in an anatase/rutile mixed phase (92.1 % vs. 7.9 %, respectively) with very small anatase crystallites (3.7 nm). The TiO2 lattice is nitrized both at interstitial and substitutional positions. NST features a negatively charged surface with a remarkable surface area (406 m2 g−1), endowed with special adsorption capabilities towards cationic dyes. Its photocatalytic behavior was tested by following the degradation of standard aqueous methylene blue and methyl orange solutions under UV and visible light irradiation, according to ISO 10678:2010. For comparison, analogous investigations were carried out on a silica-free N−TiO2, obtained by using NH4Cl as nitrogen source. 相似文献
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164.
A new triphenylphosphine oxide reagent linked to a linear maleimide-styrene copolymer is synthesized. This phosphine-bound copolymer is converted to copolymer-supported triphenylphosphine ditriflate as a novel Hendrickson reagent by treatment with triflic anhydride. This reacts rapidly in various dehydration reactions such as anhydride, ester and amide formation. This linear and soluble support is also easily recovered and recycled several times without loss of efficiency. 相似文献
165.
Deependra M. Shakya Otega A. Ejegbavwo Thayalan Rajeshkumar Sanjaya D. Senanayake Amy J. Brandt Sharfa Farzandh Narayan Acharya Amani M. Ebrahim Anatoly I. Frenkel Ning Rui Gregory L. Tate John R. Monnier Konstantinos D. Vogiatzis Natalia B. Shustova Donna A. Chen 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(46):16685-16689
We report the first study of a gas‐phase reaction catalyzed by highly dispersed sites at the metal nodes of a crystalline metal–organic framework (MOF). Specifically, CuRhBTC (BTC3?=benzenetricarboxylate) exhibited hydrogenation activity, while other isostructural monometallic and bimetallic MOFs did not. Our multi‐technique characterization identifies the oxidation state of Rh in CuRhBTC as +2, which is a Rh oxidation state that has not previously been observed for crystalline MOF metal nodes. These Rh2+ sites are active for the catalytic hydrogenation of propylene to propane at room temperature, and the MOF structure stabilizes the Rh2+ oxidation state under reaction conditions. Density functional theory calculations suggest a mechanism in which hydrogen dissociation and propylene adsorption occur at the Rh2+ sites. The ability to tailor the geometry and ensemble size of the metal nodes in MOFs allows for unprecedented control of the active sites and could lead to significant advances in rational catalyst design. 相似文献
166.
Heshmatian Saeed Bahiraei Mehdi Amani Mohammad 《Journal of Thermal Analysis and Calorimetry》2019,137(2):607-622
Journal of Thermal Analysis and Calorimetry - Irreversibility factors for the TiO2–water nanofluid flow are evaluated through entropy generation rates caused by friction and heat transfer by... 相似文献
167.
Amani Atayat Lucia Mergola Nadia Mzoughi Roberta Del Sole 《Journal of separation science》2019,42(18):3023-3032
The aim of this work was to develop an efficient method for the selective extraction and analysis of fenoxycarb, a carbamate pesticide, in mussel samples using a molecularly imprinted solid‐phase extraction device. The optimization of molecularly imprinted polymer synthesis was performed using the experimental design under the response surface methodology approach. A fast rebinding study and Freundlich isotherm adsorption were carried out to calculate binding capacity B, site number n, and affinity constant Kf. The optimum molecularly imprinted polymer was successfully used as sorbent of a solid‐phase extraction cartridge for the determination of fenoxycarb in real mussel samples. The range of linearity was 0.3–30 mg/L with a correlation coefficient of 0.991. The limit of detection was 0.247 mg/kg. The recovery of fenoxycarb extracted from mussel samples of Mediterranean sea was 97% (n = 3) with relative standard deviation between 6 and 7% proving the reliability of the developed method. 相似文献
168.
Faisal K. Algethami Ilyes Saidi Hani Nasser Abdelhamid Mohamed R. Elamin Babiker Y. Abdulkhair Amani Chrouda Hichem Ben Jannet 《Molecules (Basel, Switzerland)》2021,26(17)
Diabetes mellitus is a major health problem globally. The management of carbohydrate digestion provides an alternative treatment. Flavonoids constitute the largest group of polyphenolic compounds, produced by plants widely consumed as food and/or used for therapeutic purposes. As such, isoxazoles have attracted the attention of medicinal chemists by dint of their considerable bioactivity. Thus, the main goal of this work was to discover new hybrid molecules with properties of both flavonoids and isoxazoles in order to control carbohydrate digestion. Moreover, the trifluoromethyl group is a key entity in drug development, due to its strong lipophilicity and metabolic stability. Therefore, the present work describes the condensation of a previously synthesized trifluoromethylated flavonol with different aryl nitrile oxides, affording 13 hybrid molecules indicated as trifluoromethylated flavonoid-based isoxazoles. The structures of the obtained compounds were deduced from by 1H NMR, 13C NMR, and HRMS analysis. The 15 newly synthesized compounds inhibited the activity of α-amylase with an efficacy ranging from 64.5 ± 0.7% to 94.7 ± 1.2% at a concentration of 50 μM, and with IC50 values of 12.6 ± 0.2 μM–27.6 ± 1.1 μM. The most effective compounds in terms of efficacy and potency were 3b, 3h, 3j, and 3m. Among the new trifluoromethylated flavonoid-based isoxazoles, the compound 3b was the most effective inhibitor of α-amylase activity (PI = 94.7 ± 1.2% at 50 μM), with a potency (IC50 = 12.6 ± 0.2 μM) similar to that of the positive control acarbose (IC50 = 12.4 ± 0.1 μM). The study of the structure–activity relationship based on the molecular docking analysis showed a low binding energy, a correct mode of interaction in the active pocket of the target enzyme, and an ability to interact with the key residues of glycosidic cleavage (GLU-230 and ASP-206), explaining the inhibitory effects of α-amylase established by several derivatives. 相似文献
169.
In this paper, we consider F(R,T) gravity as a linear function of the curvature and torsion scalars and interact it with logarithmic entropy corrected holographic dark energy to evaluate cosmology solutions. The model is investigated by FRW metric, and then the energy density and the pressure of dark energy are calculated. Also we obtain equation of state (EoS) parameter of dark energy and plot it with respect to both variable of redshift and e-folding number. Finally, we describe the scenario in three status: early, late and future time by e-folding number. 相似文献
170.
Amani Jaafar Adeline Fix-Tailler Najwa Mansour Magali Allain Wassim N. Shebaby Wissam H. Faour Sima Tokajian Abdelkrim El-Ghayoury Daoud Naoufal Jean-Philippe Bouchara Gérald Larcher Ghassan Ibrahim 《应用有机金属化学》2020,34(12):e5988
The reactions of Cu (II), Zn (II) and Cd (II) chloride or bromide with (E)-1-(3,4-dimethoxybenzylidene)-4-methylthiosemicarbazone (MTSVT) lead to the formation of new complexes. They were characterized by spectroscopic studies: IR, 1H and 13C NMR. The crystal structures of the compounds [MTSVT] ( L ), [ZnBr2(MTSVT)2] ( 2 ), [CdCl2(MTSVT)2] ( 3 ) and [CdBr2(MTSVT)2.H2O] ( 4 ) were determined by X-ray diffraction. For complexes 2 – 4 , the ion is coordinated through the sulfur atom. All compounds were tested for their antifungal activity against human pathogenic fungi Candida albicans and Aspergillus fumigatus, and for their antibacterial activity against Gram (+) Bacillus subtilis and Enterococcus faecalis as well as against Gram (−) bacteria such as Paracoccus yeei and Acinetobacter baumanii. The results indicated that the metal complexes exhibited a marked enhancement in antibacterial activity compared with the parent Schiff base. 相似文献