scholarly journals Improving the stability and optical properties of germanane via one-step covalent methyl-termination

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Shishi Jiang ◽  
Sheneve Butler ◽  
Elisabeth Bianco ◽  
Oscar D. Restrepo ◽  
Wolfgang Windl ◽  
...  
Keyword(s):  
Optical Properties ◽  
One Step ◽  
The Stability

Effects of finite-rate chemistry and detailed transport on the instability of jet diffusion flames

2014 ◽  
Vol 745 ◽  
pp. 647-681 ◽  
Author(s):  
Yee Chee See ◽  
Matthias Ihme
Keyword(s):  
Transport Properties ◽  
Diffusion Flames ◽  
Diffusive Transport ◽  
Mean Flow ◽  
Stability Behaviour ◽  
Jet Diffusion Flames ◽  
One Step ◽  
The Mean ◽  
Modelling Assumptions ◽  
The Stability

AbstractLocal linear stability analysis has been shown to provide valuable information about the response of jet diffusion flames to flow-field perturbations. However, this analysis commonly relies on several modelling assumptions about the mean flow prescription, the thermo-viscous-diffusive transport properties, and the complexity and representation of the chemical reaction mechanisms. In this work, the effects of these modelling assumptions on the stability behaviour of a jet diffusion flame are systematically investigated. A flamelet formulation is combined with linear stability theory to fully account for the effects of complex transport properties and the detailed reaction chemistry on the perturbation dynamics. The model is applied to a methane–air jet diffusion flame that was experimentally investigated by Füriet al.(Proc. Combust. Inst., vol. 29, 2002, pp. 1653–1661). Detailed simulations are performed to obtain mean flow quantities, about which the stability analysis is performed. Simulation results show that the growth rate of the inviscid instability mode is insensitive to the representation of the transport properties at low frequencies, and exhibits a stronger dependence on the mean flow representation. The effects of the complexity of the reaction chemistry on the stability behaviour are investigated in the context of an adiabatic jet flame configuration. Comparisons with a detailed chemical-kinetics model show that the use of a one-step chemistry representation in combination with a simplified viscous-diffusive transport model can affect the mean flow representation and heat release location, thereby modifying the instability behaviour. This is attributed to the shift in the flame structure predicted by the one-step chemistry model, and is further exacerbated by the representation of the transport properties. A pinch-point analysis is performed to investigate the stability behaviour; it is shown that the shear-layer instability is convectively unstable, while the outer buoyancy-driven instability mode transitions from absolutely to convectively unstable in the nozzle near field, and this transition point is dependent on the Froude number.

A one-step roll-to-roll process of stable AgNW/PEDOT:PSS solution using imidazole as a mild base for highly conductive and transparent films: optimizations and mechanisms

2015 ◽  
Vol 3 (22) ◽  
pp. 5859-5868 ◽  
Author(s):  
Seyul Kim ◽  
So Yeon Kim ◽  
Moon Hyun Chung ◽  
Jeonghun Kim ◽  
Jung Hyun Kim
Keyword(s):  
Optical Properties ◽  
Electrical And Optical Properties ◽  
Transparent Films ◽  
Slot Die Coating ◽  
Roll To Roll ◽  
Transparent Conducting ◽  
Slot Die ◽  
Coating Method ◽  
One Step

An AgNW/PEDOT:PSS coated, transparent, conducting, roll film (460 mm in width × 20 m in length) with good electrical and optical properties was produced using the roll-to-roll slot-die coating method.

scholarly journals Concomitant polymorphs of aryl-ether amine via catemer and dimer carboxylic acid supramolecular interactions and their effect on optical properties

2021 ◽  
Author(s):  
Mehboobali Pannipara ◽  
Abdullah G Al-Sehemi
Keyword(s):  
Optical Properties ◽  
Carboxylic Acid ◽  
Crystal Lattice ◽  
Functional Groups ◽  
Molecular Orbital ◽  
Acid Group ◽  
Supramolecular Interactions ◽  
Aryl Ether ◽  
Stability Calculation ◽  
The Stability

Abstract Carboxylic acid supramolecular synthon exhibited dimer or catemer motifs in the crystal lattice depend on the substituent and other functional groups present in the structure. In general, presence of other competing functional groups produced catemer motifs whereas unsubstituted acids showed dimer. In this manuscript, we have synthesized a new aryl ether amine-based Schiff base with carboxylic acid functionality ( 1 ) and demonstrated polymorphic structure via catemer ( 1a ) and dimer ( 1b ) motifs in the solid state. In both the structure, carboxylic acid group adopted different orientation in the crystal lattice. The different H-bonding lead to modulation of optical properties that was further supported highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) calculation. Further the stability calculation indicates that catemer structure was more stable by 8.54 kcal/mole relative to dimer motifs. In contrast, naphthyl group attached carboxylic acid structure did not show neither dimer nor catemer motifs in the crystal lattice as compared to diethylaminophenyl group, which confirm the presence of other substituent or competing functional groups strongly influence on the motifs of supramolecular interactions.

scholarly journals New palladium–oxazoline complexes: Synthesis and evaluation of the optical properties and the catalytic power during the oxidation of textile dyes

2015 ◽  
Vol 11 ◽  
pp. 1175-1186 ◽  
Author(s):  
Rym Hassani ◽  
Mahjoub Jabli ◽  
Yakdhane Kacem ◽  
Jérôme Marrot ◽  
Damien Prim ◽  
...  
Keyword(s):  
Optical Properties ◽  
Spectroscopic Analysis ◽  
Palladium Complexes ◽  
X Ray Diffraction ◽  
Factors Affecting ◽  
Enantiomerically Pure ◽  
One Step ◽  
Uv Visible ◽  
High Yields

The present paper describes the synthesis of new palladium–oxazoline complexes in one step with good to high yields (68–95%). The oxazolines were prepared from enantiomerically pure α-aminoalcohols. The structures of the synthesized palladium complexes were confirmed by NMR, FTIR, TOFMS, UV–visible spectroscopic analysis and X–ray diffraction. The optical properties of the complexes were evaluated by the determination of the gap energy values (E g) ranging between 2.34 and 3.21 eV. Their catalytic activities were tested for the degradation of Eriochrome Blue Black B (a model of azo dyes) in the presence of an ecological oxidant (H2O2). The efficiency of the decolorization has been confirmed via UV–visible spectroscopic analysis and the factors affecting the degradation phenomenon have been studied. The removal of the Eriochrome reached high yields. We have found that the complex 9 promoted 84% of color elimination within 5 min (C 0 = 30 mg/L, T = 22 °C, pH 7, H2O2 = 0.5 mL) and the energetic parameters have been also determined.

A systematic study of the stability, electronic and optical properties of beryllium and nitrogen co-doped graphene

Carbon ◽  
2018 ◽  
Vol 129 ◽  
pp. 207-227 ◽  
Author(s):  
O. Olaniyan ◽  
R.E. Maphasha ◽  
M.J. Madito ◽  
A.A. Khaleed ◽  
E. Igumbor ◽  
...  
Keyword(s):  
Optical Properties ◽  
Systematic Study ◽  
Electronic And Optical Properties ◽  
Doped Graphene ◽  
The Stability ◽  
Co Doped

Stability of carbon monoxide oxidation process on gold nanoparticles

2020 ◽  
Vol 8 (1) ◽  
pp. 116-124
Author(s):  
P. P. Kostrobij ◽  
◽  
I. A. Ryzha ◽  
Keyword(s):  
Carbon Monoxide ◽  
Gold Nanoparticles ◽  
Reaction Mechanisms ◽  
Structural Changes ◽  
Oxidation Process ◽  
Lyapunov Method ◽  
Catalyst Surface ◽  
Carbon Monoxide Oxidation ◽  
One Step ◽  
The Stability

The stability conditions for mathematical models of carbon monoxide oxidation on the surface of gold nanoparticles are investigated. The cases of reaction mechanisms of one-step and step-by-step transformation of reagents are consecutively considered. Using the stability analysis by Lyapunov method, it is shown that models which take into account the possibility of structural changes of the catalyst surface can predict the occurrence of oscillatory mode in the system as a result of Hopf instability.

Synthesis, structural revolutions, and optical properties of SnO2 hollow microspheres with manageable shell thickness

CrystEngComm ◽  
2021 ◽  
Author(s):  
Xin Zhang ◽  
Xueyan Jia ◽  
Zihang Shi ◽  
Bolun Song ◽  
Yongan Niu
Keyword(s):  
Optical Properties ◽  
Calcination Temperature ◽  
Shell Thickness ◽  
Hollow Microspheres ◽  
One Step ◽  
Sio2 Microspheres

SnO2 hollow (H-SnO2) microspheres were successfully prepared via a facile one-step synthesis using SiO2 microspheres as templates and NaOH as reactive etching agent. To determine the calcination temperature, the thermal...

Exploration on performance of two-dimensional GaN photocathodes with uniform-doping and variable-doping structure

2021 ◽  
Author(s):  
Liangbo Huang ◽  
Jian Tian ◽  
Lei Liu ◽  
Ruxiao Di ◽  
Zihao Zhu
Keyword(s):  
Optical Properties ◽  
Work Function ◽  
Formation Energy ◽  
Electron Transition ◽  
Two Dimensional ◽  
Density Of State ◽  
Electron Escape ◽  
The Stability ◽  
Function Density ◽  
Uniform Doping

In this paper, the properties of two-dimensional (2D) gallium nitride (GaN) photocathodes with a uniform doping and variable doping structure are studied by using Mg as a doping element based on first principles. The stability, bandstructure, work function, density of state and optical properties of the GaN bilayer and GaN trilayer in two-doped ways are investigated. The results show that formation energy of variable doping structure is less than that of the uniform doping structure, which means that the variable doping structure is more stable. At the same time, the formation energy increases with increase of layers. The pristine GaN bilayer has an indirect bandgap, while the doped GaN bilayer transforms into a direct bandgap. The impurity levels appear in a forbidden band of doped GaN trilayers, which is favorable for electron transition. The results of work function reveal that variable doping structure has lower vacuum barriers and more electron escape numbers, which proves that it can improve the quantum efficiency of photocathodes. Finally, the analysis of optical properties shows that the uniform doping structure has better optical properties than that of the variable doping structure.

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