scholarly journals Effect of Different Rotational Speeds on Graphene-Wrapped SiC Core-Shell Nanoparticles in Wet Milling Medium

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 944
Author(s):  
Dong Liang ◽  
Ling Yan ◽  
Kunkun Huang ◽  
Yan Li ◽  
Fangfang Ai ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Conversion Efficiency ◽  
Rotational Speed ◽  
No Oxidation ◽  
Experimental Result ◽  
Wet Milling ◽  
Shell Nanoparticles ◽  
Graphene Layers ◽  
Rotating Speed ◽  
Milling Medium

The effects of the wet milling rotating speed on the number of graphene layers and graphene quality, and the conversion efficiency of graphite exfoliate to graphene, were investigated by scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The results show that the number of few-layer graphene nanometer sheets (GNSs) (≤10 layers) gradually increases with the increase of rotational speed in the range of 160–240 rpm. The proportion of GNSs with 0–10 layers reaches more than 80% as the rotational speed is increased to 280 rpm. GNS defect types in the composite materials are marginal defects with minimal influence and almost no oxidation. In the range of 160–280 rpm, the intensity of graphite peak decreases and the conversion efficiency of graphene increases with the increase of rotational speed. This is the same as the experimental result obtained by HRTEM.

scholarly journals Variably Sized and Multi-Colored Silica-Nanoparticles Characterized by Fluorescence Correlation Methods for Cellular Dynamics

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 19
Author(s):  
Chan-Gi Pack ◽  
Bjorn Paulson ◽  
Yeonhee Shin ◽  
Min Kyo Jung ◽  
Jun Sung Kim ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Correlation Spectroscopy ◽  
Cell Uptake ◽  
Core Shell ◽  
Therapeutic Effects ◽  
Ferrite Core ◽  
Shell Nanoparticles ◽  
Fluorescence Correlation ◽  
Correlation Methods

Controlling the uptake of nanoparticles into cells so as to balance therapeutic effects with toxicity is an essential unsolved problem in the development of nanomedicine technologies. From this point of view, it is useful to use standard nanoparticles to quantitatively evaluate the physical properties of the nanoparticles in solution and in cells, and to analyze the intracellular dynamic motion and distribution of these nanoparticles at a single-particle level. In this study, standard nanoparticles are developed based on a variant silica-based nanoparticle incorporating fluorescein isothiocyanate (FITC) or/and rhodamine B isothiocyanate (RITC) with a variety of accessible diameters and a matching fluorescent cobalt ferrite core-shell structure (Fe2O4/SiO2). The physical and optical properties of the nanoparticles in vitro are fully evaluated with the complementary methods of dynamic light scattering, electron microscopy, and two fluorescence correlation methods. In addition, cell uptake of dual-colored and core/shell nanoparticles via endocytosis in live HeLa cells is detected by fluorescence correlation spectroscopy and electron microscopy, indicating the suitability of the nanoparticles as standards for further studies of intracellular dynamics with multi-modal methods.

scholarly journals Structural and chemical characterization of MoO2/MoS2 triple-hybrid materials using electron microscopy in up to three dimensions

2021 ◽  
Author(s):  
Anna Frank ◽  
Thomas Gänsler ◽  
Stefan Hieke ◽  
Simon Fleischmann ◽  
Samantha Husmann ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Chemical Characterization ◽  
Three Dimensions ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Microscopy Investigation ◽  
Electron Microscopy Investigation ◽  
Carbon Nanotube Network ◽  
Core Shell Nanoparticles

This work presents the synthesis of MoO2/MoS2 core/shell nanoparticles within a carbon nanotube network and their detailed electron microscopy investigation in up to three dimensions. The triple-hybrid core/shell material was...

Feasibility investigation of a compressor rotor supported by gas foil bearings with inhomogeneous bump foils

2021 ◽  
pp. 135065012110046
Author(s):  
Hao Li ◽  
Haipeng Geng ◽  
Bo Wang ◽  
Wei Zheng
Keyword(s):  
Critical Speed ◽  
Rotor System ◽  
Experimental Result ◽  
Test Results ◽  
Rotating Speed ◽  
Foil Bearings ◽  
Dynamic Coefficients ◽  
High Order Harmonic ◽  
Compressor Rotor ◽  
Operating Points

In this paper, a rotordynamic experiment on a compressor rotor system is presented and the feasibility of gas foil bearings with inhomogeneous bump foils is verified. A push–pull device is designed to obtain the stiffness curve and the nominal clearance of foil bearings. Operating points and dynamic coefficients of the rotor system at each rotating speed are predicted. In rotordynamic analysis, an alternative model of the impeller is proposed and the critical speed is predicted by employing the finite element method, in which the dynamic coefficients of inhomogeneous foil bearings are taken into account. Compared with the experimental result, the accuracy of the prediction for the critical speed is verified to be about 14% error. Two sets of foil bearings with 22 and 41 μm nominal clearance are manufactured and tested. Test results indicate that the vibration amplitude can be greatly reduced by diminishing the bearing clearance. When foil bearings with 22 μm clearance are used, the high-order harmonic frequencies of rotor vibration are significantly inhibited, and the amplitude of the rotating frequency is obviously restricted. Thus, the foil bearing with inhomogeneous bump foils tested in this paper can meet the speed requirement of the compressor when the nominal clearance is set at 22 μm.

scholarly journals Cu-Ag core-shell nanoparticles: A direct correlation between micro-Raman and electron microscopy

2006 ◽  
Vol 73 (11) ◽  
Author(s):  
M. Cazayous ◽  
C. Langlois ◽  
T. Oikawa ◽  
C. Ricolleau ◽  
A. Sacuto
Keyword(s):  
Electron Microscopy ◽  
Core Shell ◽  
Shell Nanoparticles ◽  
Core Shell Nanoparticles

Effect of Different Processing on Corn Starch and Protein

2012 ◽  
Vol 554-556 ◽  
pp. 990-993
Author(s):  
Jian Zou ◽  
Hai Yan Gao ◽  
Jie Zeng
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Corn Starch ◽  
Ultra Violet ◽  
Absorption Spectrometry ◽  
Dry Milling ◽  
Wet Milling ◽  
Corn Flour ◽  
Sds Page ◽  
Scanning Electron

Scanning electron microscopy of samples showed that corn flour granules by fermented and wet-milling were angular, pentagonal or elliptical similar to native starches while samples with extruding and cooking were irregularly fibrous and large granules. Protein of samples with wet-milling exhibited an obvious DSC endotherm, To 85.81°C, Tp 92.95°C, Tc 101.73°C and ΔH 1.614J/g.While the fermented and extruded samples had no endotherm. Ultra-violet absorption spectrometry showed that absorbance of fermented and extruded samples increased and the λmax were slightly red shift. The λmax were 294nm, 297nm and 310nm for wet-milling , fermented and extruded flour, respectively. SDS-PAGE patterns of wet-milling flour contained four bands, fermented samples only three bands while extruded samples had same bands with dry-milling.

scholarly journals Investigations of Inducers Operating With High Rotational Speed

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Björn Gwiasda ◽  
Matthias Mohr ◽  
Martin Böhle
Keyword(s):  
Rotational Speed ◽  
Test Bench ◽  
Pressure Rise ◽  
Working Fluid ◽  
Cfd Simulations ◽  
High Rotational Speed ◽  
Rotating Speed ◽  
Performance Pressure ◽  
Computational Fluid Dynamics Cfd ◽  
Suction Performance

Suction performance, pressure rise, and efficiency for four different inducers are examined with computational fluid dynamics (CFD) simulations and experiments performed with 18,000 rpm and 24,000 rpm. The studies originate from a research project that includes the construction of a new test bench in order to judge the design of the different inducers. This test bench allows to conduct experiments with a rotational speed of up to 40,000 rpm and high pressure ranges from 0.1 bar to 40 bar with water as working fluid. Experimental results are used to evaluate the accuracy of the simulations and to gain a better understanding of the design parameter. The influence of increasing the rotating speed from 18,000 rpm to 24,000 rpm on the performance is also shown.

scholarly journals 1.5-W 520 nm Continuous-wave Output from a 50μm/0.22NA Fiber-Coupled Laser Diode Module

2021 ◽  
Author(s):  
Bojie Lou ◽  
Bing Ding ◽  
Zhangwang Miao ◽  
Pengfei Zhao ◽  
Haijuan Yu ◽  
...  
Keyword(s):  
Conversion Efficiency ◽  
Continuous Wave ◽  
Numerical Aperture ◽  
Experimental Result ◽  
Optical Conversion Efficiency ◽  
Core Diameter ◽  
Central Wavelength ◽  
High Brightness ◽  
Optical Conversion ◽  
Final Output

Abstract In this paper, a high brightness fiber-coupled module with a central wavelength of 520nm is simulated and designed by ray-tracing software ZEMAX, and then is experimentally implemented. Three 1-w continuous-wave green LD single emitters based on TO-9-package are successively collimated, spatially combined, and focused into an optical fiber with a core diameter of 50 μm and a numerical aperture of 0.22. The final output power of 1.53w is obtained, corresponding to an optical-optical conversion efficiency of 51% and an electro-optical conversion efficiency of 10%, and the tolerance between the simulation and the experimental result is analyzed and explained.

Characterization of Friction Stir Welding on Aluminum

2009 ◽  
Vol 68 ◽  
pp. 167-174 ◽  
Author(s):  
Jerry Wong ◽  
Patricia del C. Zambrano ◽  
Martha Patrizia Guerrero-Mata ◽  
Victor Mucino ◽  
Rafael Colás
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Carrying Capacity ◽  
Feeding Rate ◽  
Load Carrying Capacity ◽  
Rotating Speed ◽  
Friction Stir ◽  
Load Carrying ◽  
Scanning Electron

A series of linear and spot stir welding friction tests were carried out on aluminum samples of 1 mm in thickness and area of 100 mm x 27 mm. The tool rotating speed was varied from 2000 to 4000 RPM and the feeding rate from 45 to 67.8 mm/min. The temperature distribution during welding was measured by thermocouples inserted within the aluminum strips. The microstructure of the welded nuggets and the HAZ were analyzed by optical and scanning electron microscopy. Some samples were tested intension to measure the load carrying capacity of the welded bead. Preliminary analyses indicate that the temperature at the heat affected zone increases with the rotating speed.

Casting Recycling of Animal Protein-Based Binder Sand

2012 ◽  
Vol 573-574 ◽  
pp. 1156-1160
Author(s):  
Hong Yu Shi ◽  
Hui Liu ◽  
Shu Lan Guo
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Protein Binding ◽  
Animal Protein ◽  
Experimental Result ◽  
Environmental Friendly ◽  
Traditional Technologies ◽  
Scanning Electron

This study is focusing on the protein sand binder on the performance of wet sand, and explores the protein binding mold sand reusability and reclamation. With thermal analysis and scanning electron microscopy testing, and by comparing with other traditional technologies, the experimental result shows that it is a more environmental friendly.

Temperature Dependent Structural Evolution of Graphene Layers on 4H-SiC(0001)

2011 ◽  
Vol 679-680 ◽  
pp. 797-800 ◽  
Author(s):  
Sushant Sonde ◽  
Carmelo Vecchio ◽  
Filippo Giannazzo ◽  
Corrado Bongiorno ◽  
Salvatore di Franco ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Structural Evolution ◽  
Morphological Transformation ◽  
Temperature Dependent ◽  
Microscopy Imaging ◽  
Graphene Layers ◽  
Force Microscopy ◽  
Atomic Force ◽  
Transmission Electron ◽  
Mode Atomic Force Microscopy

In this study we examined the structural evolution of graphene grown on 8° off-axis 4H-SiC(0001) substrates at temperatures from 1600°C to 1700°C in Ar ambient. Morphological transformation of SiC substrate after annealing was examined by Tapping Mode Atomic Force Microscopy. Moreover, by etching-out graphene layers from graphitized SiC substrates in selective trenches we determined the number of graphene layers. Numbers of graphene layers were then independently confirmed by Transmission Electron Microscopy imaging.

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