A5103023675- Calcium Carbonate Crystallization and Inhibition
- Iron oxide chemistry and applications
- Geochemistry and Elemental Analysis
- Minerals Flotation and Separation Techniques
- Paleontology and Stratigraphy of Fossils
- Microplastics and Plastic Pollution
- Advanced Electron Microscopy Techniques and Applications
- Microbial Fuel Cells and Bioremediation
- Carbon Nanotubes in Composites
- Climate change and permafrost
- Metal Extraction and Bioleaching
- Advanced X-ray Imaging Techniques
- Mine drainage and remediation techniques
- Microbial Community Ecology and Physiology
- Clay minerals and soil interactions
- Advanced Materials Characterization Techniques
- Silicon Effects in Agriculture
- Soil Carbon and Nitrogen Dynamics
- Radioactive element chemistry and processing
- Recycling and Waste Management Techniques
- Peatlands and Wetlands Ecology
- Aquatic Ecosystems and Phytoplankton Dynamics
- X-ray Spectroscopy and Fluorescence Analysis
- Methane Hydrates and Related Phenomena
- Phosphorus and nutrient management
University of Bayreuth
2016-2024
University of Chinese Academy of Sciences
2022
Leibniz Centre for Agricultural Landscape Research
2022
Institute of Crop Science
2022
University of Bonn
2022
Sino-Danish Centre for Education and Research
2022
Canadian Light Source (Canada)
2007-2018
McMaster University
2007-2018
Norcada (Canada)
2018
University of Tübingen
2009-2014
Abstract Phosphorus availability in soils is an important parameter influencing primary production terrestrial ecosystems. limitation exists many since a high proportion of soil phosphorus stored unavailable forms for plants, such as bound to iron minerals or stabilized organic matter. This spite having amount total phosphorus. The feasibility silicon mobilize from strong binding sites has been shown marine sediments but less well studied soils. Here we tested the effect on mobilization 143...
Abstract Due to the abundance of microplastics in environment, research about its possible adverse effects is increasing exponentially. Most studies investigating effect on cells still rely commercially available polystyrene microspheres. However, choice these model microplastic particles can affect outcome studies, as even nominally identical may interact differently with due different surface properties such charge. Here, we show that microspheres from eight manufacturers significantly...
Abstract Environmental microplastic (MP) is ubiquitous in aquatic and terrestrial ecosystems providing artificial habitats for microbes. Mechanisms of MP colonization, polymer impacts, effects on soil microbiomes are largely unknown systems. Therefore, we experimentally tested the hypothesis that type an important deterministic factor affecting community assembly by incubating common types situ landfill 14 months. 16S rRNA gene amplicon sequencing indicated polymers have specific impacts...
Abstract Rice cultivation requires high amounts of phosphorus (P). However, significant P fertilizer additions may be retained by iron (Fe) oxides and are thus unavailable for plants. At the same time, rice has a demand silicic acid (Si), reducing Si availability after short duration cultivation. By studying paddy chronosequence with up to 2000 years, we show that limitation, observed as early few decades cultivation, is limiting along soils chronosequence. Using near edge X-ray absorption...
Quantitative three-dimensional (3D) chemical mapping using angle-scan spectro-tomography in a scanning transmission (soft) X-ray microscope (STXM) has been used for the first time to characterize early stages of CaCO(3) biomineral nucleation on surface planktonic freshwater cyanobacterial cells strain Synechococcus leopoliensis PCC 7942. The apparatus STXM tomography is described. Aspects sample preparation, mounting and data acquisition quantitative analysis interpretation are discussed...
Microbial oxidation of sulfur-rich mining waste materials drives acid mine drainage (AMD) and affects the global sulfur biogeochemical cycle. The generation AMD is a complex, dynamic process that proceeds via multiple reaction pathways. role natural consortia microbes in generation, however, has received very little attention despite their widespread occurrence environments. Through combination geochemical experimentation modeling, scanning transmission X-ray microscopy, fluorescent situ...
Thawing permafrost forms "thaw ponds" that accumulate and transport organic carbon (OC), redox-active iron (Fe), other elements. Although Fe has been shown to act as a control on the microbial degradation of OC in soils, role cycling thaw ponds remains poorly understood. Here, we investigated Fe-OC interactions partially fully thawed soils ("bog" "fen" ponds, respectively) peatland complex Abisko, Sweden, using size separation (large particulate fraction (LPF), small (SPF), dissolved (DF)),...
The polarization dependence (linear dichroism) of the C 1s X-ray absorption spectrum individual multi-walled carbon nanotubes (MWCNTs) is measured using scanning transmission microscopy. A very strong dichroic effect found in --> pi* transition, with almost complete disappearance this transition when electric-field (E)-vector aligned parallel to high-quality (low-defect) MWCNTs and maximum intensity E-vector orthogonal tube axis. In contrast, there little dichroism sigma* transitions. origin...
We report the design and performance of a 3-electrode device for real time in situ scanning transmission X-ray microscopy studies electrochemical processes under both static (sealed, non-flow) conditions with continuous flow electrolytes. The was made using combination silicon microfabrication 3D printing technologies. is illustrated by results study copper deposition stripping at gold working electrode. absorption spectromicroscopy Cu 2p edge used to follow evolution as function potential...
Abstract Chemical nano-tomography of microbial cells in their natural, hydrated state provides direct evidence metabolic and chemical processes. Cells the nitrate-reducing Acidovorax sp. strain BoFeN1 were cultured presence ferrous iron. Bacterial reduction nitrate causes precipitation Fe(III)-(oxyhydr)oxides periplasm vicinity cells. Nanoliter aliquots cell-suspension injected into custom-designed sample holders wherein polyimide membranes collapse around by capillary forces. The...
The alignment of β-sheets within spider dragline silk fibers is an important factor in their tensile strength and extensibility. We are using linear dichroism the C 1s → π*amide transition measured scanning transmission X-ray microscopy (STXM) to generate quantitative maps <P2> orientation parameters with 30 nm spatial resolution. Here we have extended these measurements from dry samples partial or full hydration. A device for monitoring controlling humidity a sample STXM described used...
We have used the recently completed soft X-ray spectromicroscopy facility at Canadian Light Source (CLS) to study individual multi-walled carbon nanotubes (MWCNTs) with scanning transmission microscopy (STXM). Specifically, spatially resolved C 1s absorption linear dichroism signals were map structural defects. The STXM on CLS 10ID1 beamline is particularly powerful for such studies since its elliptically polarized undulator provides fully linearly X-rays their E-vector orientation...