scholarly journals Computational Study of Urea–Water Solution Sprays for the Analysis of the Injection Process in SCR-like Conditions

2020 ◽  
Vol 59 (41) ◽  
pp. 18659-18673
Author(s):  
Raúl Payri ◽  
Gabriela Bracho ◽  
Pedro Martí-Aldaraví ◽  
Javier Marco-Gimeno
Keyword(s):  
Computational Study ◽  
Water Solution ◽  
Injection Process

Reactivity and stability of plasma-generated oxygen and nitrogen species in buffered water solution: a computational study

2019 ◽  
Vol 21 (24) ◽  
pp. 12881-12894 ◽  
Author(s):  
Pepijn Heirman ◽  
Wilma Van Boxem ◽  
Annemie Bogaerts
Keyword(s):  
Biomedical Applications ◽  
Computational Study ◽  
Water Solution ◽  
Nitrogen Species

Plasma-treated liquids have great potential for biomedical applications.

scholarly journals Micro-Solvated DMABN: Excited State Quantum Dynamics and Dual Fluorescence Spectra

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7247
Author(s):  
Sandra Gómez ◽  
Esra N. Soysal ◽  
Graham A. Worth
Keyword(s):  
Electronic Structure ◽  
Excited State ◽  
Quantum Dynamics ◽  
Computational Study ◽  
Water Solution ◽  
Fluorescence Emission ◽  
Spectroscopic Properties ◽  
Complete Analysis ◽  
Solvent Molecules ◽  
Dynamics Simulations

In this work, we report a complete analysis by theoretical and spectroscopic methods of the short-time behaviour of 4-(dimethylamino)benzonitrile (DMABN) in the gas phase as well as in cyclohexane, tetrahydrofuran, acetonitrile, and water solution, after excitation to the La state. The spectroscopic properties of DMABN were investigated experimentally using UV absorption and fluorescence emission spectroscopy. The computational study was developed at different electronic structure levels and using the Polarisable Continuum Model (PCM) and explicit solvent molecules to reproduce the solvent environment. Additionally, excited state quantum dynamics simulations in the diabatic picture using the direct dynamics variational multiconfigurational Gaussian (DD-vMCG) method were performed, the largest quantum dynamics “on-the-fly” simulations performed with this method until now. The comparison with fully converged multilayer multiconfigurational time-dependent Hartree (ML-MCTDH) dynamics on parametrised linear vibronic coupling (LVC) potentials show very similar population decays and evolution of the nuclear wavepacket. The ring C=C stretching and three methyl tilting modes are identified as the responsible motions for the internal conversion from the La to the Lb states. No major differences are observed in the ultrafast initial decay in different solvents, but we show that this effect depends strongly on the level of electronic structure used.

A Computational Study on Iridium‐Catalyzed Production of Acetic Acid from Ethanol and Water Solution

2019 ◽  
Vol 37 (9) ◽  
pp. 883-886 ◽  
Author(s):  
Xin Yue ◽  
Longfei Li ◽  
Pengjie Li ◽  
Chenguang Luo ◽  
Min Pu ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Computational Study ◽  
Water Solution

scholarly journals EXPERIMENTAL AND COMPUTATIONAL STUDY OF LIQUID OSCILLATION DAMPING IN A FREE SURFACE VESSEL

2021 ◽  
pp. 24-43
Author(s):  
Andriy Kozhushko
Keyword(s):  
Experimental Research ◽  
Computational Study ◽  
Water Solution ◽  
Experimental Studies ◽  
Theoretical Models ◽  
Maximum Error ◽  
Free Oscillations ◽  
Mathematical Algorithm ◽  
Damping Decrement ◽  
Mathematical Algorithms

Studying the issues related to solving the problems of the movement of fluid in partially filled structures of various shapes has always been relevant.This is due, in particular, to the need to ensure the longitudinal and lateral stability of the movement of objects in which the liquid is transported. Contemporarymethods and research tools that allow describing the movement of liquid in a container are overly complex and require in-depth knowledgefrom a scientist. Therefore, development of a mathematical algorithm that would be simple and at the same time ensure sufficient accuracy in determiningthe oscillatory motion in a container is advisable. Each development of a new mathematical algorithm requires experimental research to verifyits adequacy. The purpose of this work is to confirm the feasibility of using the created mathematical apparatus for determining the main parameters offree vibrations depending on the level of liquid in a rectangular prismatic container. The experimental research methodology provides for checking theadequacy of the mathematical algorithms in determining the frequencies of free oscillations of liquid in a container by comparing the theoretical andexperimental values of the oscillation periods, as well as determining the damping decrement of oscillations for liquids of different viscosity. As a result,the adequacy of the formulas for determining the frequencies of free oscillations of liquid in a container is proved; the maximum error does notexceed 4.35%. The decrements of vibration damping are determined experimentally, as well as using theoretical models of the motion of viscous liquidin the so-called partial surface layers, for three liquids of different viscosity, namely, for water, for 20% sugar and water solution, and for vegetable oil.On the basis of experimental studies, the amplitudes and frequencies of forced vibrations of various types of liquids are determined by constructing anamplitude-frequency characteristic. It is shown by calculation how the damping decrement of the liquid affects the value of the horizontal displacementof the surface layer of the liquid in the tank during its transportation by a wheeled tractor.

scholarly journals Taking Lanthanides out of Isolation: Tuning the Optical Properties of Metal-Organic Frameworks

2020 ◽  
Author(s):  
Samantha L. Anderson ◽  
Davide Tiana ◽  
Christopher Ireland ◽  
Gloria Capano ◽  
Maria Fumanal ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Electronic Properties ◽  
Rational Design ◽  
Computational Study ◽  
Water Solution ◽  
Metal Organic Frameworks ◽  
Visible Region ◽  
Co Catalysts ◽  
Optical And Electronic Properties ◽  
Metal Organic

<div>Metal organic frameworks (MOFs) are increasingly used in applications that rely on the optical and electronic properties of these materials. These applications require a fundamental understanding on how the structure of these materials, and in particular the electronic interactions of the metal node and organic linker, determines these properties. </div><div><br></div><div>Herein, we report a combined experimental and computational study on two families of lanthanide-based MOFs: Ln-SION-1 and Ln-SION-2. Both comprise the same metal and ligand but with differing structural topologies. In the Ln-SION-2 series the optical absorption is dominated by the ligand and using different lanthanides has no impact on the absorption spectrum. The Ln-SION-1 series shows a completely different behavior in which the ligand and the metal node do interact electronically. By changing the lanthanide in Ln-SION-1, we were able to tune the optical absorption from the UV region to absorption that includes a large part of the visible region. For the early lanthanides we observe intraligand (electronic) transitions in the UV region, while for the late lanthanides a new band appears in the visible. DFT calculations showed that the new band in the visible originates in the spatial orbital overlap between the ligand and metal node. Our quantum calculations indicated that Ln-SION-1 with late lanthanides might be (photo)conductive. Experimentally, we confirm that these materials are weakly conductive and that with an appropriate co-catalysts they can generate hydrogen from a water solution using visible light. Our experimental and theoretical analysis provides fundamental insights for the rational design of Ln-MOFs with the desired optical and electronic properties.</div>

scholarly journals Theoretical Investigation of Glycine Micro-Solvated. Energy and NMR Spin Spin Coupling Constants Calculations

Sci ◽  
2021 ◽  
Vol 3 (4) ◽  
pp. 41
Author(s):  
Maria Cristina Caputo ◽  
Patricio Federico Provasi
Keyword(s):  
Gas Phase ◽  
Density Functional ◽  
Computational Study ◽  
Water Solution ◽  
Polarizable Continuum Model ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Basis Set ◽  
Spin Coupling Constants ◽  
Spin Spin Coupling

Glycine in its neutral form can exist in the gas phase while its zwitterion form is more stable in water solution, but how many waters are actually necessary to stabilize the zwitterionic structure in the gas phase? Are the intramolecular isotropic spin spin coupling constants sensitive enough to accuse the change in the environment? or the conformer observed? These and related questions have been investigated by a computational study at the level of density functional theory employing the B3LYP functional and the 6-31++G**-J basis set. We found that at least two water molecules explicitly accounted for in the super-molecule structure are necessary to stabilize both conformers of glycine within a water polarizable continuum model. At least half of the SSCCs of both conformers are very stable to changes in the environment and at least four of them differ significantly between Neutral and Zwitterion conformation.

scholarly journals Inside Cover: A Computational Study on Iridium‐Catalyzed Production of Acetic Acid from Ethanol and Water Solution (Chin. J. Chem. 9/2019)

2019 ◽  
Vol 37 (9) ◽  
pp. 862-862
Author(s):  
Xin Yue ◽  
Longfei Li ◽  
Pengjie Li ◽  
Chenguang Luo ◽  
Min Pu ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Computational Study ◽  
Water Solution

scholarly journals Taking Lanthanides out of Isolation: Tuning the Optical Properties of Metal-Organic Frameworks

2020 ◽  
Author(s):  
Samantha L. Anderson ◽  
Davide Tiana ◽  
Christopher Ireland ◽  
Gloria Capano ◽  
Maria Fumanal ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Electronic Properties ◽  
Rational Design ◽  
Computational Study ◽  
Water Solution ◽  
Metal Organic Frameworks ◽  
Visible Region ◽  
Co Catalysts ◽  
Optical And Electronic Properties ◽  
Metal Organic

<div>Metal organic frameworks (MOFs) are increasingly used in applications that rely on the optical and electronic properties of these materials. These applications require a fundamental understanding on how the structure of these materials, and in particular the electronic interactions of the metal node and organic linker, determines these properties. </div><div><br></div><div>Herein, we report a combined experimental and computational study on two families of lanthanide-based MOFs: Ln-SION-1 and Ln-SION-2. Both comprise the same metal and ligand but with differing structural topologies. In the Ln-SION-2 series the optical absorption is dominated by the ligand and using different lanthanides has no impact on the absorption spectrum. The Ln-SION-1 series shows a completely different behavior in which the ligand and the metal node do interact electronically. By changing the lanthanide in Ln-SION-1, we were able to tune the optical absorption from the UV region to absorption that includes a large part of the visible region. For the early lanthanides we observe intraligand (electronic) transitions in the UV region, while for the late lanthanides a new band appears in the visible. DFT calculations showed that the new band in the visible originates in the spatial orbital overlap between the ligand and metal node. Our quantum calculations indicated that Ln-SION-1 with late lanthanides might be (photo)conductive. Experimentally, we confirm that these materials are weakly conductive and that with an appropriate co-catalysts they can generate hydrogen from a water solution using visible light. Our experimental and theoretical analysis provides fundamental insights for the rational design of Ln-MOFs with the desired optical and electronic properties.</div>

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