A5014097284- Atmospheric aerosols and clouds
- Freezing and Crystallization Processes
- nanoparticles nucleation surface interactions
- Advanced Optical Sensing Technologies
- Atmospheric chemistry and aerosols
- Ocular and Laser Science Research
- Atmospheric and Environmental Gas Dynamics
- Arctic and Antarctic ice dynamics
- Icing and De-icing Technologies
- Surface Roughness and Optical Measurements
- Water Quality Monitoring and Analysis
- Impact of Light on Environment and Health
- Remote Sensing and LiDAR Applications
- Fire effects on ecosystems
- Adaptive optics and wavefront sensing
- Spectroscopy and Laser Applications
- Air Quality Monitoring and Forecasting
- Food Industry and Aquatic Biology
- Remote Sensing in Agriculture
Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR)
2018-2023
Karlsruhe Institute of Technology
2014-2018
Heidelberg University
2016
University of Duisburg-Essen
2012
Abstract. A recently designed droplet freezing assay was used to study the of up 1500 identical 0.2 nL water droplets containing suspensions one Na/Ca-rich feldspar and three K-rich particles. Three types experiments have been conducted: cooling ramp, isothermal at a constant temperature, freeze–thaw cycles. The observed behavior has interpreted with help model based on classical nucleation theory (soccer ball (SBM); Niedermeier et al., 2015). By applying different conducted same...
Abstract. The second phase of the Fifth International Ice Nucleation Workshop (FIN-02) involved gathering a large number researchers at Karlsruhe Institute Technology's Aerosol Interactions and Dynamics Atmosphere (AIDA) facility to promote characterization understanding ice nucleation measurements made by variety methods used worldwide. Compared previous workshop in 2007, participation was doubled, reflecting vibrant research area. Experimental sampling aerosol particles direct processing...
The deliquescence behavior of ternary inorganic (ammonium sulfate and ammonium nitrate)/organic (glutaric acid malonic acid)/water aerosol particles has been investigated at 293 K using a novel surface microscopy (SAM) technique. results obtained for the relative humidities (DRH) variable inorganic/organic contents show eutectic with mixed showing lower DRH compared to pure organic components, respectively. This quantitatively modeled extended inorganics (E-AIM) thermodynamic model Clegg et...
Recent laboratory studies indicate that the hydrated form of crystalline NaCl is potentially important for atmospheric processes involving depositional ice nucleation on dihydrate particles under cirrus cloud conditions. However, recent experimental reported a strong discrepancy between temperature intervals where efflorescence has been observed. Here we report measurements volume specific rate in aqueous solution droplets pure suspended an electrodynamic balance at constant and humidity...
Abstract. A recently designed droplet freezing assay was used to study the of up 1500 identical 0.2 nL water droplets containing suspensions three K-rich and one Na/Ca-rich feldspar particles. Three types experiments have been conducted: cooling ramp, isothermal at constant temperature, freeze-thaw cycles. The observed behavior interpreted with help a model based on classical nucleation theory (Soccer Ball Model, SBM, Niedermeier, (2015). Applying different conducted same ice nucleating...
Abstract. Immersion freezing is the most relevant heterogeneous ice nucleation mechanism through which crystals are formed in mixed-phase clouds. In recent years, an increasing number of laboratory experiments utilizing a variety instruments have examined immersion activity atmospherically nucleating particles (INPs). However, inter-comparison these results difficult task because investigators used different (IN) measurement methods to produce results. A remaining challenge explore...
A numerical model is developed to simulate the angle dependent light scattering. The based on Mie theory and uses complex refractive indices of aerosol particles rain droplets together with their corresponding experimental number size distributions as input parameters. laser beam parameters high energy at DLR transmission test range in Lampoldshausen geometry detection system are taken into consideration. It demonstrated that accurately predicts absolute scattered powers obtained by a...
Measurements of parameters the natural atmospheric environment, like aerosol and precipitation distributions as well visibility, are simultaneously performed together with angle dependent scattering high power laser radiation. These measurements were obtained on free transmission test range operated by German Aerospace Center (DLR) in Lampoldshausen. The applied disk system operates at a wavelength 1030 nm all presented an output 3000 W continuous wave. beam is propagating along 130 m focus...
Absorption and scattering by gaseous species, aerosol particles precipitation lead to atmospheric attenuation of laser radiation. High power propagation over long horizontal and/or vertical distances is significantly affected in outdoor locations. Laser transmission experiments can be used derive experimental extinction coefficients, which included the assessment safety. However, a full representation effect types on high unknown authors. at 1030 nm under rainy snowy weather conditions were...
Regulations of safety usage hazardous substances impose companies to monitor their emissions. A novel approach determines the mass concentration Cr(VI) in exhaust airflow based on angular light scattering combined with machine learning algorithms.
S1 Estimation of surface area per dropletThe SEM (FEI QUANTA 650 FEG) was used to measure the particles in FS02 suspension droplets.The images taken at different resolution (Fig. S1) were estimate total projection and size distribution residual left after droplet evaporated.The individual has been measured with program ImageJ 1.47v for derivation equivalent particle diameter assuming sphericity.The can either be converted into a by counting frequency diameters or summing up particles.The...
The propagation of laser radiation over long distances can be significantly affected by atmospheric extinction due to precipitation as well aerosol particles and molecules. knowledge the contribution is critical operation a variety laser-based systems. study high-power transmission around 1 µm particular interest because several windows are located in this region. To investigate effect adverse weather conditions on transmission, free-space experiments conducted DLR test range Lampoldshausen,...
The outdoor operation of multi-kilowatt high-power lasers involves the potential hazard exposing human eye and skin to scattered radiation. In present laser safety standards regulations, effects atmospheric off-axis scattering dynamic interaction between beam target object are not adequately represented. Therefore, experimental studies dedicated providing quantitative information on radiation for comprehensive evaluations. With this end in view, a mobile detection system has been developed...
The accurate quantification of scattered laser radiation is crucial for estimating threats to humans from outdoor applications high-power lasers. In addition the hazard due intrabeam viewing, specular and diffuse reflections irradiated targets can potentially harm human eye skin. Measurement techniques detection have been developed in way provide quantitative information advanced analyses as well proofs further improvements safety calculations. system has be calibrated, characterized...
The operation of lasers in free space involves the potential risk unintentionally exposing human eye and skin to radiation. In addition direct exposure, indirect scattered radiation high-power may pose a threat operators, working personnel, third parties. Hazard assessments are usually performed based on laser safety standards. However, these standards would have be extended for outdoor environments therefore it is advisable substantiate models calculations with measurements absolute radiant...
High power laser radiation scattered outside of the beam axis can be a potential threat. A novel detection system based on angular light scattering help to access risk by atmospheric particles.