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- Simulation of yarn transportation (1)
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Scanning Electron Microscopy (SEM) or Transmission Electron Microscopy (TEM) ? This is a question, nowadays discussed in EM labs of research and industry involved in the characterization and metrology of nanoparticles. The Scanning principle is adapted to TEM, the Transmission mode is adapted to Ultra High Resolution SEM. Can modern SEM replace TEM, reach atomic resolution even without Cs corrector or nm lateral resolution for energydispersive X-ray spectroscopy (EDX)?
Due to the development of a New Cold Field Emission (NCFE) electron source Hitachi SEMs SU9000 and SU8200 can deliver routinely sub-nm image resolution and EDX mappings at very high count rates and a lateral EDX resolution of a few nm. A TiO2 sample provided by BAM was analysed at 30kV using low kV STEM – simultaneously with the Through-the-lens (TTL) SE detector, the Bright Field transmitted and Dark Field transmitted signals. By this method a pixel precise information of the particles surface using SE, its chemical nature using DF-STEM and its crystalline structure using Bright Field signal is given in one 40sec scan. The advantage of this observation mode compared to Ultra Low Voltage imaging is outlined.
Scanning Electron Microscopy (SEM) or Transmission Electron Microscopy (TEM) ? This is a question, nowadays discussed in EM labs of research and industry involved in the characterization and metrology of nanoparticles. The Scanning principle is adapted to TEM, the Transmission mode is adapted to Ultra High Resolution SEM. Can modern SEM replace TEM, reach atomic resolution even without Cs corrector or nm lateral resolution for X-ray Spectroscopy (EDX)?
Due to the development of a New Cold Field Emission (NCFE) electron source Hitachi SEMs SU9000 and SU8200 can deliver routinely sub-nm image resolution and EDX mappings at very high count rates and a lateral EDX resolution of a few nm. A TiO2 sample provided by BAM was analysed at 30 kV using low kV STEM – simultaneously with the Through-the-lens (TTL) SE detector, the Bright Field transmission and Dark Field transmission signals. By this method a pixel-precise information of the particle’s surface using SE, its chemical nature using DF-STEM and its crystalline structure using Bright Field signal is given in one 40sec scan. The advantage of this observation mode compared to Ultra Low Voltage imaging is outlined.
Advances in scanning electron microscopy (SEM) enable the high-resolution imaging of single nanoparticles (NPs) with sizes well below 10 nm. The SEM analysis in transmission mode (T-SEM) of NPs on thin film supports has many benefits when compared to the analysis of NPs on bulk substrates. The enhanced material (mass - thickness) contrast of the T-SEM imaging mode is well suited for in-depth and, particularly valuable, to very accurate, traceable, lateral dimensional measurements of NPs. Compared to samples prepared on bulk substrates, T-SEM with energy dispersive X-ray spectroscopy (EDS) achieves a drastically improved spatial resolution of the emitted X-rays. The poor signal-to-noise ratio of the X-ray spectra emitted by a single nanoparticle (NP) can be improved by the use of high-sensitivity (high collection solid angle) silicon drift (SDD), energy-dispersive X-ray spectrometers (EDS). The EDS spectral imaging of a single NP with a spatial resolution below 10 nm has become possible. This is demonstrated by means of various examples of nanostructures. Advanced data processing of T-SEM/EDS results sets the stage for the automated classification of NPs by feature analysis. This method combines the detection of morphological structures of interest by image processing of T-SEM micrographs with the chemical classification by EDS.
To date, in the textile manufacturing process of warp knitting, trouble-shooting and process optimization mainly rely on empirical knowledge and experiments. This factor limits the achievable increase in productivity and quality. On the other hand, using simulations, different phenomena that affect the quality of the knitted fabric and the knitting process can be clarified in the run-up of the experiments. Consequently, an increase in quality and flexibility can be reached with reduced experimental effort. This paper presents a process simulation of the warp thread dynamics in the thread feeding system of a warp knitting machine. For this purpose, a continuum model of the warp thread that includes the spatial dynamics of the thread and the axial transport movement has been developed.