29DFT-based Theoretical Simulation on Electronic Transition for Graphene Oxides in Solvent Media

2021 ◽  
pp. 118049
Author(s):  
Zhaomin Meng ◽  
Xiaoning Yang ◽  
Houyi Li
Keyword(s):  
Electronic Transition ◽  
Graphene Oxides ◽  
Theoretical Simulation

Dispersibility Evaluation of Graphene Oxides with Alkyl Chain Groups by Using Optical Transparency

2015 ◽  
Vol E98.C (2) ◽  
pp. 127-128 ◽  
Author(s):  
Asami OHTAKE ◽  
Seiko UCHINO ◽  
Kunio AKEDO ◽  
Masanao ERA ◽  
Koichi SAKAGUCHI
Keyword(s):  
Alkyl Chain ◽  
Optical Transparency ◽  
Graphene Oxides

scholarly journals Mono-dispersed Ag nanoparticles decorated graphitic carbon nitride: An excellent lubricating additive as PPESK composite film

Friction ◽  
2021 ◽  
Author(s):  
Beibei Chen ◽  
Mengjie Zhang ◽  
Kan Zhang ◽  
Zhe Dong ◽  
Jiaye Li ◽  
...  
Keyword(s):  
Composite Film ◽  
Ag Nanoparticles ◽  
Carbon Nitride ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Great Promise ◽  
Theoretical Simulation ◽  
Heavy Loads ◽  
20 Nm ◽  
Ball On Disc

AbstractStudies show that two dimensional (2D) nanomaterial and its hybrid have a great promise in tribology for the special laminar microstructure. However, the majority of performed investigations about 2D graphitic carbon nitride (g-C3N4) nanosheets are most focused on energy storage, catalysis, adsorption, rarely tribology. In the present study, g-C3N4 supporting mono-dispersed Ag nanoparticle hybrid (g-C3N4/Ag) is prepared, and its microstructure and chemical composition are determined. More specifically, the tribological performance as the lubricating additive of poly phthalazinone ether sulfone ketone (PPESK) composite is investigated using the ball-on-disc friction tester. Moreover, the corresponding enhancement mechanism is well proposed based on the experimental analysis and theoretical simulation. Obtained results show that Ag nanoparticles with a size of about 10–20 nm are homogeneously anchored on g-C3N4 nanosheets, favoring for good compatibility between g-C3N4/Ag and PPESK. It is found that when 0.3 wt% of g-C3N4/Ag is added to PPESK, the friction coefficient and wear rate of PPESK decrease by 68.9% and 97.1%, respectively. These reductions are mainly attributed to the synergistic self-lubricating effect of Ag nanoparticles and g-C3N4 nanosheet, the formation of transfer film, as well as the limited effect of g-C3N4/Ag on the shear deformation of PPESK composite film. Furthermore, it is found that the proposed g-C3N4/Ag-PPESK composite still keeps reasonable friction-reducing and wear-resistant properties under heavy loads and high rotating speeds. The present study demonstrates that the proposed g-C3N4/Ag hybrid is an excellent lubricating additive for polymer composites.

scholarly journals Spectroscopic Techniques versus Pitot Tube for the Measurement of Flow Velocity in Narrow Ducts

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7349
Author(s):  
Francesco D’Amato ◽  
Silvia Viciani ◽  
Alessio Montori ◽  
Marco Barucci ◽  
Carmen Morreale ◽  
...  
Keyword(s):  
Flow Field ◽  
Flow Velocity ◽  
Pitot Tube ◽  
Optical Measurements ◽  
Trace Gas ◽  
Dual Function ◽  
Spectroscopic Techniques ◽  
Gas Composition ◽  
Flow Conditions ◽  
Theoretical Simulation

In order to assess the limits and applicability of Pitot tubes for the measurement of flow velocity in narrow ducts, e.g., biomass burning plants, an optical, dual function device was implemented. This sensor, based on spectroscopic techniques, targets a trace gas, injected inside the stack either in bursts, or continuously, so performing transit time or dilution measurements. A comparison of the two optical techniques with respect to Pitot readings was carried out in different flow conditions (speed, temperature, gas composition). The results of the two optical measurements are in agreement with each other and fit quite well the theoretical simulation of the flow field, while the results of the Pitot measurements show a remarkable dependence on position and inclination of the Pitot tube with respect to the duct axis. The implications for the metrology of small combustors’ emissions are outlined.

scholarly journals Development and Prospect of UAV-Based Aerial Electrostatic Spray Technology in China

2021 ◽  
Vol 11 (9) ◽  
pp. 4071
Author(s):  
Yali Zhang ◽  
Xinrong Huang ◽  
Yubin Lan ◽  
Linlin Wang ◽  
Xiaoyang Lu ◽  
...  
Keyword(s):  
Plant Protection ◽  
Structure Design ◽  
Research Progress ◽  
Theoretical Simulation ◽  
Spray System ◽  
Charged Droplets ◽  
Agricultural Use ◽  
Field Efficiency ◽  
The Impact ◽  
Electrostatic Spray

Aerial electrostatic spray technology for agriculture is the integration of precision agricultural aviation and electrostatic spray technology. It is one of the research topics that have been paid close attention to by scholars in the field of agricultural aviation. This study summarizes the development of airborne electrostatic spray technology for agricultural use in China, including the early research and exploration of Chinese institutions and researchers in the aspects of nozzle structure design optimization and theoretical simulation. The research progress of UAV-based aerial electrostatic spray technology for agricultural use in China was expounded from the aspects of nozzle modification, technical feasibility study, influencing mechanism of various factors, and field efficiency tests. According to the current development of agricultural UAVs and the characteristics of the farmland environment in China, the UAV-based aerial electrostatic spray technology, which carries the airborne electrostatic spray system on the plant protection UAVs, has a wide potential in the future. At present, the application of UAV-based aerial electrostatic spray technology has yet to be further improved due to several factors, such as the optimization of the test technology for charged droplets, the impact of UAV rotor wind field, comparison study on charging modes, and the lack of technical accumulation in the research of aerial electrostatic spray technology. With the continuous improvement of the research system of agricultural aviation electrostatic spray technology, UAV-based electrostatic spray technology will give play to the advantages in increasing the droplets deposition on the target and reducing environmental pollution from the application of pesticides. This study is capable of providing a reference for the development of the UAV-based agricultural electrostatic spray technology and the spray equipment.

scholarly journals Theoretical simulation of different 3D separator geometries for lithium-ion batteries

2020 ◽  
Author(s):  
D. Miranda ◽  
R. Gonçalves ◽  
F. Miranda ◽  
A. M. Almeida ◽  
C. M. Costa ◽  
...  
Keyword(s):  
Lithium Ion Batteries ◽  
Lithium Ion ◽  
Theoretical Simulation

scholarly journals Exploring the Structure–Performance Relationship of Sulfonated Polysulfone Proton Exchange Membrane by a Combined Computational and Experimental Approach

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 959
Author(s):  
Cataldo Simari ◽  
Mario Prejanò ◽  
Ernestino Lufrano ◽  
Emilia Sicilia ◽  
Isabella Nicotera
Keyword(s):  
High Performance ◽  
Mechanical Stability ◽  
Structural Parameters ◽  
Hydration Number ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Water Dynamics ◽  
Mechanical Resistance ◽  
Theoretical Simulation ◽  
Sulfonated Polysulfone

Sulfonated Polysulfone (sPSU) is emerging as a concrete alternative to Nafion ionomer for the development of proton exchange electrolytic membranes for low cost, environmentally friendly and high-performance PEM fuel cells. This ionomer has recently gained great consideration since it can effectively combine large availability on the market, excellent film-forming ability and remarkable thermo-mechanical resistance with interesting proton conductive properties. Despite the great potential, however, the morphological architecture of hydrated sPSU is still unknown. In this study, computational and experimental advanced tools are combined to preliminary describe the relationship between the microstructure of highly sulfonated sPSU (DS = 80%) and its physico-chemical, mechanical and electrochemical features. Computer simulations allowed for describing the architecture and to estimate the structural parameters of the sPSU membrane. Molecular dynamics revealed an interconnected lamellar-like structure for hydrated sPSU, with ionic clusters of about 14–18 Å in diameter corresponding to the hydrophilic sulfonic-acid-containing phase. Water dynamics were investigated by 1H Pulsed Field Gradient (PFG) NMR spectroscopy in a wide temperature range (20–120 °C) and the self-diffusion coefficients data were analyzed by a “two-sites” model. It allows to estimate the hydration number in excellent agreement with the theoretical simulation (e.g., about 8 mol H2O/mol SO3− @ 80 °C). The PEM performance was assessed in terms of dimensional, thermo-mechanical and electrochemical properties by swelling tests, DMA and EIS, respectively. The peculiar microstructure of sPSU provides a wider thermo-mechanical stability in comparison to Nafion, but lower dimensional and conductive features. Nonetheless, the single H2/O2 fuel cell assembled with sPSU exhibited better features than any earlier published hydrocarbon ionomers, thus opening interesting perspectives toward the design and preparation of high-performing sPSU-based PEMs.

Sign in / Sign up

Export Citation Format

Share Document