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Development and validation of SuperDEM for non-spherical particulate systems using a superquadric particle method

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Particuology 2022年第2期20卷 74-90页

作者： Xi Gao Jia Yu Ricardo J.F.Portal jean-François Dietiker Mehrdad Shahnam William A.rogers National Energy Technology Laboratory MorgantownWV 26506USA Leidos Research Support Team MorgantownWV 26506USA Centro de Investigação em Modelação e Otimização de Sistemas Multifuncionais Instituto Superior de Engenharia de LisboaPolytechnic Institute of Lisbon1959-007 LisboaPortugal Instituto de Engenharia Mecânica–Instituto Superior Técnico Universidade de Lisboa1049-001 LisboaPortugal

This article presents the development and validation of the Superquadric Discrete Element Method(SuperDEM)for non-spherical particle simulation using a superquadric particle method in open-source CFD suite MFiX.A superquadric particle-particle contact algorithm with accelerating and stabilizing strategy was developed.A superquadric particle-arbitrary wall contact algorithm was developed,which enables the simulation in complex *** solver was validated by comparing with experimental data generated in this study or available in the *** include cylinder contacting with a wall,static packing of M&M chocolate candies in a cylindrical container,static packing of cylinders in a cylindrical container,dynamic angle of repose of cylinders in a rotating drum,and discharging of chocolate candies from a ***,MPI parallelization of the solver was implemented and the parallel performance of the solver using MPI was assessed through large-scale simulations of 1 million,10 million,and 100 million particles on up to 6800 cores,which demonstrates that the SuperDEM solver has great potential for industrial-scale systems simulation.

关键词： DEM Particle Non-spherical Superquadric Parallelization MFiX

Synthesis, Structural Characterization and DFT Studies of Silver(I) Complex Salt of Bis(4,5-dihydro-1<i>H</i>-benzo[g]indazole)

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Crystal Structure Theory and Applications 2017年第2期6卷 11-24页

作者： Tanyi rogers Fomuta Golngar Djimassingar jean Ngoune Nana Odette Ngnabeuye jean Jacques Anguile Justin Nenwa Department of Chemistry University of Dschang Dschang Cameroon Department of Chemistry Mongo Polytechnique University Institute (IUPM) Mongo Chad Department of Chemistry University of Sciences & Techniques of Masuku Franceville Gabon Department of Inorganic Chemistry University of Yaounde 1 Yaounde Cameroon

A new silver complex salt [Ag(N2C11H10)2]NO3 (where N2C11H10 = 4,5-dihydro-1H-benzo[g]indazole), has been synthesized and characterized by elemental and thermal analyses, IR and 1HNMR spectroscopies, single crystal X-ray structure determination and DFT studies. Its molecular structure comprises of a silver center coordinated to two nitrogen atoms from two 4,5-dihydro-1H-benzo[g]indazole molecule giving rise to a cationic complex entity, [Ag(N2C11H10)2]+ with as counter ion. The bulk structure is consolidated by N–H…O, C–H…π, Ag…π and Ag…O intermolecular interactions, thus generating a pseudo-helical network. The optimized structure, frontier molecular orbitals (HOMO and LUMO) and global reactivity descriptors were investigated by performing DFT calculations.

关键词： Silver Complex Salt 4 5-dihydro-1H-benzo[g]indazole Hydrogen Bonds Thermogravimetric Analysis 1HNMR X-Ray DFT Studies

Synthesis, Rietveld Refinement and DFT Studies of Bis(4,5-dihydro-1<i>H</i>-benzo[g]indazole)silver(I) Hexafluorophosphate Complex Salt

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Open Journal of Inorganic Chemistry 2017年第4期7卷 102-115页

作者： Tanyi rogers Fomuta jean Ngoune Golngar Djimassingar Tayo Alain Djampouo Junior Ma Ntep Tobie Matemb jean Jacques Anguile Justin Nenwa Department of Chemistry University of Dschang Dschang Cameroon Department of Chemistry Mongo Polytechnique University Institute (IUPM) Mongo Tchad Department of Chemistry University of Sciences & Techniques of Masuku Franceville Gabon Department of Inorganic Chemistry University of Yaounde 1 Yaounde Cameroon

The new salt bis(4,5-dihydro-1H-benzo[g]indazole)silver(I) hexafluorophosphate, [Ag(N2H10C11)2]PF6, has been synthesized in methanol at ambient temperature and characterized by elemental and thermal analyses, FTIR and 1HNMR spectroscopies, Rietveld refinement from powder diffraction data and DFT studies. The salt crystallizes in the triclinic space group P-1 with the parameters: a = 7.776 ?, b = 8.676 ?, c = 9.226 ?, α = 69.27° β = 89.86°, γ = 74.50°, V = 558.02 ?3, Z = 1. In the structure, the silver center is coordinated to two nitrogen atoms from two 4,5-dihydro-1H-benzo[g]indazole ligands, forming a centrosymmetric complex cation, [Ag(N2H10C11)2]+, with a linear coordination geometry around the silver center. The hexafluorophosphate ion, , acts as counter anion. The crystal packing is governed by N-H···F and C-H···F hydrogen bonds that interconnect the ionic constituents and Ag···F and Ag···π interactions help for the stabilization of the packing. The optimized structure was obtained at B3LYP/LanL2DZ level in the gas phase. The stability and reactivity of the structure were studied using respectively HOMO-LUMO gap and electronic global quantities (ionization potential (I) and electron affinity (A)) as descriptors.

关键词： Silver Complex Salt 4 5-dihydro-1H-benzo[g]indazole 1HNMR Powder Diffraction Rietveld Refinement DFT

Synthesis, Characterization and DFT Studies of Two Zinc(II) Complexes Based on 2-Isopropylimidazole

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Open Journal of Inorganic Chemistry 2018年第4期8卷 105-124页

作者： jean Jacques Anguile Odette Nana Ngnabeuye Ndosiri Ndoye Bridget Tanyi rogers Fomuta Alvine Loris Djoumbissie Alain Charly Kuate Tagne jean Ngoune Department of Chemistry University of Sciences & Techniques of Masuku Franceville Gabon Department of Chemistry University of Dschang Dschang Cameroon Department of Inorganic Chemistry University of Yaounde 1 Yaounde Cameroon

Two novel coordination compounds, [Zn(L)2(OOCH)2] (1) and [Zn(L)3(OCHO)](OCHO)]·H2O (2) (where L = 2-isopropylimidazole, C6H10N2) have been prepared by reaction of 2-isopropylimidazole with zinc(II) formate at room temperature using toluene as solvent. These compounds were characterized by elemental and thermal analyses, IR, 1HNMR and 13CNMR spectroscopies, single crystal X-ray diffraction and DFT studies. The Zn centers in 1 and 2 adopt pseudo-tetrahedral coordination geometries. Compound 1 crystallizes in the monoclinic system P2/c space group whereas compound 2 crystallizes in the P-1 space group of the triclinic crystal system. Several types of hydrogen intra-/intermolecular interactions are observed in these materials and extend into a two-dimensional leaf like network in 1 and a two-dimensional lattice of rectilinear pillars in 2. Compounds 1 and 2 were also optimized and their frontier molecular orbitals, global reactivity descriptors, molecular electrostatic potential, natural bond orbitals were investigated using density functional theory (DFT). In fact the induced structural differences from complex 1 to complex 2 led to the reduction of the frontier molecular orbital energy gap by 1.338 eV and a decrease of the chemical hardness by 0.669 eV.

关键词： Zinc(II) Complexes of 2-Isopropylimidazole Thermogravimetric Analysis 1H-MR 13C-MR Crystal Structure DFT Studies

Syntheses and Characterization of Two Novel Copper(II) Malonate Complexes Functionalized with 3,3’-Bis(pyrazolyl)pentane and 4,4’-Trimethylenedipyridine

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Open Journal of Inorganic Chemistry 2021年第2期11卷 43-53页

作者： Alvine Loris Djoumbissie Alain Clovis Tayo Djampouo Tanyi rogers Fomuta Giscard Doungmo Golngar Djimassingar Alain Charly Tagne Kuate jean Ngoune Department of Chemistry University of Dschang Dschang Cameroon Institute of Inorganic Chemistry Christian-Albrechts University of Kiel Kiel Germany Department of Chemistry Mongo Polytechnique University Institute (IUPM) Mongo Chad

Two novel copper complexes (1,2) with N,O-donor ligands were synthesized by reaction of copper(II) malonates with 3,3’-bis(pyrazolyl)pentane and 4,4’-trimethylenedipyridine in methanol at moderate temperature. These compounds were characterized by elemental analysis, UV-VIS, IR spectroscopies and powder X-ray diffraction analyses. Compound (1) melts at higher temperature (202°C) than compound (2) (100°C). The IR spectra showed typical vibrations related to C=N and C=C, characteristic of pyrazolyl and pyridine ligands.

关键词： Copper Malonate 3 3’-Bis(pyrazolyl)pentane 4 4’-Trimethylenedipyridine UV-Vis IR Powder X-Ray Diffraction

Synthesis, Structural Characterization and Computational Studies of Bis(2-Ethylimidazole) Bis(Formato)Zinc(II)-Water (1/1)

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Crystal Structure Theory and Applications 2018年第1期7卷 1-18页

作者： Nana Odette Ngnabeuye Tayo Alain Djampouo Ndosiri Ndoye Bridget Tanyi rogers Fomuta Djimassingar Golngar Tagne Alain Charly Kuate Ngoune jean Department of Chemistry University of Dschang Dschang Cameroon Department of Inorganic Chemistry University of Yaounde I Yaounde Cameroon Department of Chemistry Mongo Polytechnique University Institute (IUPM) Mongo Chad

The reaction of 2-ethylimidazole and zinc formate monohydrate in 1:2 ratio in toluene leads to the formation of bis(2-ethylimidazole)bis(formato)zinc(II)-water (1/1), [Zn(N2H8C5)2(OCHO)2]·H2O, 1 which has been characterized by several techniques, including elemental and thermal analyses, IR, 1HNMR and 13CNMR spectroscopies, single crystal X-ray diffraction and DFT studies. The results obtained show that this complex crystallizes in the orthorhombic crystal system of the Pbca space group, with cell parameters a = 14.7230(2) Å, b = 7.3880(10) Å, c = 29.0843(4) Å, α = 90°, β = 90°, γ = 90°, V = 3163.73 Å3 and Z = 8. The zinc center is bound to two molecules of 2-ethylimidazole, two formate molecules in a tetrahedral coordination geometry. One water of crystallization is present in the coordination sphere of the compound. Its molecular crystalline structure is strengthened by O/N-H…O, O-H…π, O-H…H, C-H…O, H…π, π…O and π…π interactions. The optimized structure, frontier molecular orbitals, global reactivity descriptors, molecular electrostatic potential, natural bond orbitals and the Mulliken atomic charges were investigated through theoretical studies.

关键词： Zinc Complex 2-Ethylimidazole Hydrogen Bonds Thermogravimetric Analysis 1HNMR 13CNMR X-Ray Theoretical Studies

The Impact of Substrate Materials to the Design of UWB Modern Antennas

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Journal of Computer and Communications 2016年第3期4卷 20-27页

作者： Gerard Rushingabigwi Liguo Sun Yuxing He Mengying Zhu Yongjie Li jean de Dieu Ntawangaheza Department of Electronic Engineering and Information Science Applied Electromagnetic Fields Group University of Science and Technology of China (USTC) Hefei China

The theory of microstrip antennas has motivated us to design a highly improved gain antenna under this category. It is a microstrip monopole antenna characterized by omni-directional radiation as well as a high radiation gain. A review of different methodologies to designing antennas with broad/ultra-wide band performance for various applications is enriched by our original antenna design. This is an original model analyzed over different substrate materials and finally optimized for the bandwidth of (3.3 - 5.8) GHz just below ?10 dB of return loss (RL). The antenna is judged for high gain when the ground plane size is reduced to nearly half that of substrate. The impact of the substrate materials is discussed in this article. The master design tool is Ansoft High Frequency Simulator Structure (HFSS), one of Finite Element Method (FEM) based software tools. The antenna would be printed on a 1.524 mm thick rogers (RO3003C) substrate;overall size of 33.4 × 33.4 squared millimeters. At the optimal resonance frequency of 3.8 GHz, simulation results perfectly agree with the standards of UWB antennas, with a high radiation gain and impedance matching status.

关键词： UWB Antennas Enhanced Gain FEM Ansoft HFSS