A5038477524- Advanced Electron Microscopy Techniques and Applications
- Electron and X-Ray Spectroscopy Techniques
- Advanced X-ray Imaging Techniques
- Combustion and flame dynamics
- Biofuel production and bioconversion
- Fire dynamics and safety research
- Thermochemical Biomass Conversion Processes
- Surface and Thin Film Phenomena
- X-ray Spectroscopy and Fluorescence Analysis
- Integrated Circuits and Semiconductor Failure Analysis
- Crystallography and Radiation Phenomena
- Graphene research and applications
- Fluid Dynamics and Heat Transfer
- Advancements in Photolithography Techniques
- Nuclear Physics and Applications
- Superconducting and THz Device Technology
- Advanced Combustion Engine Technologies
- Biodiesel Production and Applications
- Advanced Materials Characterization Techniques
- Force Microscopy Techniques and Applications
- Aerodynamics and Acoustics in Jet Flows
- Near-Field Optical Microscopy
- Coal Combustion and Slurry Processing
- Particle Dynamics in Fluid Flows
- Ion-surface interactions and analysis
Corrected Electron Optical Systems (Germany)
2014-2024
Universität Ulm
2022-2024
Gas Technology Institute
2011-2018
Lawrence Berkeley National Laboratory
2011-2014
University of California, Berkeley
2013
Technische Universität Dresden
2006-2012
University of Maryland, College Park
2003-2009
Heidelberg University
2003-2009
Google (United States)
2009
Heidelberg University
2008
Grain boundaries are observed and characterized in chemical vapor deposition-grown sheets of hexagonal boron nitride (h-BN) via ultra-high-resolution transmission electron microscopy at elevated temperature. Five- seven-fold defects readily along the grain boundary. Dynamics strained regions boundary resolved. The defect structures resulting out-of-plane warping consistent with recent theoretical model predictions for h-BN.
Abstract Cellulosic biomass can be directly converted to hydrocarbon transportation fuels through the use of hydropyrolysis or integrated plus hydroconversion (IH 2 ). Hydropyrolysis performed in a fast fluidized bed under 14–35 bar hydrogen pressure with an effective deoxygenation catalyst produces fungible product less than 1 total acid number which either fed refinery polished reactor produce gasoline and diesel 1% oxygen. Experimental data from 0.45 kg/h semi‐continuous IH pilot plant is...
Atomically precise tailoring of graphene can enable unusual transport pathways and new nanometer-scale functional devices. Here we describe a recipe for the controlled production highly regular "5-5-8" line defects in by means simultaneous electron irradiation Joule heating applied electric current. High-resolution transmission microscopy reveals individual steps growth process. Extending earlier theoretical work suggesting valley-discriminating capabilities 5-5-8 defect, perform...
Atomic resolution in transmission electron microscopy of thin and light-atom materials requires a rigorous reduction the beam energy to reduce knockon damage. However, at same time, chromatic aberration deteriorates TEM image dramatically. Within framework SALVE project, we introduce newly developed ${C}_{c}/{C}_{s}$ corrector that is capable correcting both spherical range accelerating voltages from 20 80 kV. The allows axial aberrations up fifth order as well dominating off-axial...
Impressive progress has been made in the processing and exploration of new material on an atomic scale (nanomaterials). However, characterization such materials by usual transmission electron microscopy (TEM) techniques suffers from drawback that phase object-modulated wave is virtually lost recorded intensity images. Electron holography opened possibilities for analyzing both amplitude wave, hence giving access to object information encoded phase. Examples include intrinsic electric...
Cellulosic biomass can be directly converted to high‐quality hydrocarbon transportation fuels through the use of integrated hydropyrolysis plus hydroconversion (IH 2® ). IH is a new process which has been developed excellent economics, and low greenhouse gas emissions. Experimental data from 50 kg/day continuous pilot plant presented demonstrates production gasoline diesel over 750 h testing. © 2013 American Institute Chemical Engineers Environ Prog, 33: 762–768, 2014
Electron diffraction gratings can be used to imprint well-defined phase structure onto an electron beam. For example, have been prepare beams with unique dislocations, such as vortex beams, which hold promise for the development of new imaging and spectroscopy techniques study materials. However, beam intensity loss associated absorption, scattering, by a binary transmission grating drastically reduces current in beam, thus possible detected signal strength it may generate. Here we describe...
Abstract For macromolecular structures determined by cryogenic electron microscopy, no technique currently exists for mapping elements to defined locations, leading errors in the assignment of metals and other ions, cofactors, substrates, inhibitors lipids that play essential roles activity regulation. Elemental microscope is well established dose-tolerant samples but challenging biological samples, especially a cryo-preserved state. Here we combine energy-loss spectroscopy with...
The surprising message of Allen et al. (Allen 1992 Phys. Rev. A 45, 8185 (doi:10.1103/PhysRevA.45.8185)) was that photons could possess orbital angular momentum in free space, which subsequently launched advancements optical manipulation, microscopy, quantum optics, communications, many more fields. It has recently been shown this result also applies to mechanical wave functions describing massive particles (matter waves). This article discusses how electron can be imprinted with quantized...
Abstract The integrated differential phase contrast (IDPC) method is useful for generating the potential map of a thin sample. We evaluate theoretically IDPC imaging thick samples by varying focus at different sample thicknesses. Our calculations show that high defocus values result in enhanced anisotropy transfer function (CTF) and uninterpretable images, if quadrant detector applied. further applying multi-sector can an almost isotropic CTF. By sector number-dependent both C c / 3...
Cs correctors have revolutionized transmission electron microscopy (TEM) in that they substantially improve point resolution and information limit. The object is found sharply localized within 0.1 nm, the intensity image can therefore be interpreted reliably on an atomic scale. However, for a conventional image, exit wave still not detected completely phase, hence indispensable missing. Therefore, example, electric-field distributions or magnetic domain structures cannot accessed. Off-axis...
Electron holography allows the reconstruction of complete electron wave, and hence offers possibility correcting aberrations. In fact, this was shown by means uncorrected CM30 Special Tübingen transmission microscope (TEM), revealing, after numerical aberration correction, a resolution approximately 0.1 nm, both in amplitude phase. However, it turned out that results suffer from comparably poor signal-to-noise ratio. The reason is limited coherent current, given gun brightness, has to...
Abstract We develop an automatic and objective method to measure correct residual aberrations in atomic-resolution HRTEM complex exit waves for crystalline samples aligned along a low-index zone axis. Our uses the approximate rotational point symmetry of column atoms or single atom iteratively calculate best-fit numerical phase plate this condition, does not require information about sample thickness precise structure. apply our two experimental focal series reconstructions, imaging β-Si 3 N...
BaTiO${}_{3}$ (BTO) nanocubes of about 50 nm in size were investigated by means off-axis electron holography combined with situ heating above and below the Curie temperature. It is shown that reconstructed phase maps BTO are associated ferroelectric polarization pattern through a mechanism could either be direct imaging internal potential or lattice variations common domain patterns.
Compact liquid-fueled swirl-stabilized combustors using advanced fuel atomization techniques provide a potential solution to challenges associated with propulsion of submerged naval vehicles. The pressurized operation combustor may alter the operational characteristics and performance also involves two-phase phenomena when exhaust gases interact surrounding water. This work describes an investigation flames created in featuring coannular swirling airflows under conditions. A central...