scholarly journals Generalized Edge effects on Graphene Nanoribbons Heterojunctions

2020 ◽  
Author(s):  
Tiago de Sousa Araújo Cassiano ◽  
Pedro Henrique de Oliveira Neto
Keyword(s):  
Electronic Properties ◽  
Graphene Nanoribbons ◽  
Length Distribution ◽  
Lagrange Equations ◽  
Future Design ◽  
Statistical Measures ◽  
Simple Geometry ◽  
Electron Phonon Coupling ◽  
The Stability ◽  
Bond Length Distribution

Graphene nanoribbons (GNRs) [1-3] are carbon-based quasi-one-dimensional strips that have provoked great interest nowadays due to some intriguing properties. Simple geometry changes can mainly control their electronic properties. This feature, allied with synthesis advances on tailoring precision, has presented the GNRs as a solid candidate to become a fundamental material in semiconductors applications in the future. Recently, a new edge design approach has gained impulse: heterojunctions. The possibility of mixing completely distinctive edge shapes opened an entirely new fashion in tailoring GNRs. Till now, just a fraction of these materials have their properties fully understood besides the encouraging prospect [2,3]. In this work, we investigated the influence of edge functionalization on arbitrary GNR heterojunctions. The model selected consists of the 2D extended SSH model with electron-phonon coupling [1]. The stationary states rise from the implementation of a self-consistent algorithm, which combines the hamiltonian diagonalization process with the consecutive solving of Euler-Lagrange equations of the expected Lagrangian value. Each heterojunction geometry was subjected to an extensive edge modification. Results unveil a relationship between the stability, electronic properties, and statistical measures of the site's spatial displacement. The energy bandgap tends to be higher when the sites have more energy. Additionally, the more disperse the bond length distribution is, the higher will be the bandgap. Therefore, the connection among these properties has critical importance for future design heterojunctions GNR.

Graphene Nanoribbons: Towards Graphitic Materials with Predefined Dimensions and Electronic Properties

2015 ◽  
Vol 19 (18) ◽  
pp. 1850-1871 ◽  
Author(s):  
Eleftherios K. Pefkianakis ◽  
Georgios Sakellariou ◽  
Georgios C. Vougioukalakis
Keyword(s):  
Electronic Properties ◽  
Graphene Nanoribbons

scholarly journals Effect of Surfactant Molecular Structure on Emulsion Stability Investigated by Interfacial Dilatational Rheology

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1127
Author(s):  
Yuejie Jin ◽  
Dingrong Liu ◽  
Jinhua Hu
Keyword(s):  
Emulsion Stability ◽  
Chain Structure ◽  
Interfacial Film ◽  
Future Design ◽  
Rheological Method ◽  
Viscoelastic Modulus ◽  
Hydrophobic Chain ◽  
Branched Chain ◽  
The Stability ◽  
Branched Structure

Polyglycerol polyricinolate (PGPR) and polyglycerol-2 dioleate were selected as model surfactants to construct water-in-oil (W/O) emulsions, and the effect of interfacial rheological properties of surfactant film on the stability of emulsions were investigated based on the interfacial dilatational rheological method. The hydrophobicity chain of PGPR is polyricinic acid condensed from ricinic acid, and that of polyglycerol-2 dioleate is oleic acid. Their dynamic interfacial tensions in 15 cycles of interfacial compression-expansion were determined. The interfacial dilatational viscoelasticity was analyzed by amplitude scanning in the range of 1–28% amplitude and frequency sweep in the range of 5–45 mHz under 2% amplitude. It was found that PGPR could quickly reach adsorption equilibrium and form interfacial film with higher interfacial dilatational viscoelastic modulus to resist the deformation of interfacial film caused by emulsion coalescence, due to its branched chain structure and longer hydrophobic chain, and the emulsion thus presented good stability. However, polyglycerol-2 dioleate with a straight chain structure had lower interfacial tension, and it failed to resist the interfacial disturbance caused by coalescence because of its lower interfacial dilatational viscoelastic modulus, and thus the emulsion was unstable. This study reveals profound understanding of the influence of branched structure of PGPR hydrophobic chain on the interfacial film properties and the emulsion stability, providing experimental reference and theoretical guidance for future design or improvement of surfactant.

scholarly journals Morphological characterization and electronic properties of pristine and oxygen-exposed graphene nanoribbons on Ag(110)

2021 ◽  
Author(s):  
Jose Eduardo Barcelon ◽  
Marco Smerieri ◽  
Giovanni Carraro ◽  
Pawel Wojciechowski ◽  
Luca Vattuone ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Quantum Confinement ◽  
Energy Gap ◽  
Graphene Nanoribbons ◽  
Morphological Characterization

Graphene nanoribbons (GNRs) are at the frontier of research on graphene materials since the 1D quantum confinement of electrons allows for the opening of an energy gap.

One-dimensional models of fourth and sixth orders for rods derived from three-dimensional elasticity

2016 ◽  
Vol 22 (2) ◽  
pp. 158-175 ◽  
Author(s):  
Erick Pruchnicki
Keyword(s):  
Order Term ◽  
Three Dimensional ◽  
Transverse Dimension ◽  
Lagrange Equations ◽  
Transverse Shearing ◽  
Natural Boundary Conditions ◽  
The Stability ◽  
Shearing Energy ◽  
Three Dimensional Elasticity ◽  
Double Symmetry

The displacement field in rods can be approximated by using a Taylor–Young expansion in transverse dimension of the rod. These involve that the highest-order term of shear is of second order in the transverse dimension of the rod. Then we show that transverse shearing energy is removed by the fourth-order truncation of the potential energy and so we revisit the model presented by Pruchnicki. Then we consider the sixth-order truncation of the potential which includes transverse shearing and transverse normal stress energies. For these two models we show that the potential energies satisfy the stability condition of Legendre–Hadamard which is necessary for the existence of a minimizer and then we give the Euler–Lagrange equations and the natural boundary conditions associated with these potential energies. For the sake of simplicity we consider that the cross-section of the rod has double symmetry axes.

The Stability Control of Soft Soil Foundations of Urban Roads According to the Surface Subsidence Monitoring Data

2013 ◽  
Vol 859 ◽  
pp. 222-227
Author(s):  
Hong Jun Liu ◽  
Jin Hua Tan ◽  
Xue Wen Su ◽  
Hao Wu
Keyword(s):  
Soft Soil ◽  
Stability Control ◽  
Surface Subsidence ◽  
Monitoring Data ◽  
Research Results ◽  
The Road ◽  
Future Design ◽  
Left And Right ◽  
Soil Foundation ◽  
The Stability

Two typical monitoring sections are selected for obtaining the change law of the surface subsidence and the settlement after construction of soft soil foundations, and determining the reasonable unloading time. The research results show that the surface settlement rate is large during the filling stage, the rate decreases after the loading and gradually stabilized. The embankment midline settlement is larger than the settlement of the road shoulder which is concluded from the fact that the subsidence of the middle settlement plate is larger than those of the left and right plate. The surface subsidence rate is less than 5mm per month during the two month before unloading according to the data in the tables. The settlement after construction presumed from the middle plate is more significantly larger than that of left and right sides, hence, as the unloading basis of preloading drainage method in soft soil foundation treatment the settlement after construction which is calculated from the midline monitoring data of the road is appropriate. After 6 months the calculated post-construction settlements of the two sections are in the scope of the design requirement since they decrease with preloading time. The reliable basis is provided for the future design and construction of soft foundation in this area through the research results.

Electronic properties and reactivity of oxidized graphene nanoribbons and their interaction with phenol

2021 ◽  
Vol 28 (1) ◽  
Author(s):  
Santiago José Guevara-Martínez ◽  
Francisco Villanueva-Mejia ◽  
Luis Olmos ◽  
Pedro Navarro-Santos ◽  
Manuel Arroyo-Albiter
Keyword(s):  
Electronic Properties ◽  
Graphene Nanoribbons

Analytical and Experimental Flutter Analysis of a Typical Wing Section Carrying a Flexibly Mounted Unbalanced Engine

2019 ◽  
Vol 19 (02) ◽  
pp. 1950013 ◽  
Author(s):  
A. S. Mirabbashi ◽  
A. Mazidi ◽  
M. M. Jalili
Keyword(s):  
Stability Domain ◽  
Governing Equations ◽  
Lagrange Equations ◽  
Wing Section ◽  
Unbalanced Force ◽  
Engine Thrust ◽  
Finite State Model ◽  
Flutter Analysis ◽  
Finite State ◽  
The Stability

In this paper, both experimental and analytical flutter analyses are conducted for a typical 5-degree of freedon (5DOF) wing section carrying a flexibly mounted unbalanced engine. The wing flexibility is simulated by two torsional and longitudinal springs at the wing elastic axis. One flap is attached to the wing section by a torsion spring. Also, the engine is connected to the wing by two elastic joints. Each joint is simulated by a spring and damper unit to bring the model close to reality. Both the torsional and longitudinal motions of the engine are considered in the aeroelastic governing equations derived from the Lagrange equations. Also, Peter’s finite state model is used to simulate the aerodynamic loads on the wing. Effects of various engine parameters such as position, connection stiffness, mass, thrust and unbalanced force on the flutter of the wing are investigated. The results show that the aeroelastic stability region is limited by increasing the engine mass, pylon length, engine thrust and unbalanced force. Furthermore, increasing the damping and stiffness coefficients of the engine connection enlarges the stability domain.

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