A5007895251- Quantum Chromodynamics and Particle Interactions
- Atmospheric chemistry and aerosols
- Atmospheric Ozone and Climate
- High-Energy Particle Collisions Research
- Particle physics theoretical and experimental studies
- Nuclear physics research studies
- Air Quality Monitoring and Forecasting
- Nuclear Physics and Applications
- Air Quality and Health Impacts
- Atomic and Subatomic Physics Research
- Nuclear reactor physics and engineering
- Advanced NMR Techniques and Applications
- Scientific Research and Discoveries
- Calibration and Measurement Techniques
- Catalysis and Oxidation Reactions
- Sulfur Compounds in Biology
- Advanced Chemical Sensor Technologies
- Mass Spectrometry Techniques and Applications
- Atomic and Molecular Physics
- Spectroscopy and Laser Applications
- Radiation Detection and Scintillator Technologies
- Geology and Paleoclimatology Research
- Atmospheric aerosols and clouds
- Advanced Chemical Physics Studies
- Water Quality Monitoring and Analysis
Forschungszentrum Jülich
2021-2024
University of Cologne
2017-2023
University of Rochester
1967-1971
University of Notre Dame
1970-1971
Abstract. Hydroxyl radical (OH) reactivity, which is the inverse lifetime of OH radical, provides information on burden air pollutants, since almost all pollutants react with OH. reactivity measurements from field experiments can help to identify gaps in measurement individual reactants and serve as a proxy for potential formation secondary including ozone particles. However, not regularly measured specifically airborne platforms due technical complexity instruments and/or need careful...
Acyl peroxy nitrates (APNs) are important secondary pollutants in the troposphere, acting as reservoir for NOx (=NO2+NO). The relatively long lifetime of APNs (around 40 min at 298K) allows them to be transported from highly polluted areas remote areas, causing an increase both and ozone concentrations on site. Various techniques used measure field laboratory experiments. These include direct methods such Gas Chromatography (GC), Chemical Ionization Mass Spectrometry (CIMS), well indirect...
This paper highlights the importance of including reversible formation non-acyl peroxynitrate species in chemical mechanisms to correctly predict concentration peroxy radicals which are pivotal secondary pollutants.
The photooxidation of five anthropogenic volatile organic compounds (propane, propene, isopentane, n-hexane, trans-2-hexene) at different levels nitric oxide (NO) was investigated in the atmospheric simulation chamber SAPHIR, Forschungszentrum Jülich. Measured time series trace gases and radical concentrations are compared to zero-dimensional box model calculations, based on Master Chemical Mechanism (agreement within 30%) complemented by state-of-the-art structure–activity relationships...
The previously observed enhancement between 1100 and 1400 MeV in the $K\ensuremath{\pi}\ensuremath{\pi}$ mass spectrum is interpreted as a $T=\frac{1}{2}$, ${J}^{P}={1}^{+}$ resonance at 1280\ifmmode\pm\else\textpm\fi{}20 width of 130 \ifmmode\pm\else\textpm\fi{} 15 which decays into $\ensuremath{\pi}+{K}^{*}$ $K+\ensuremath{\rho}$. Evidence also presented supporting existence newly reported $L$ meson.
We have studied the production and decay characteristics of low-mass ${K}^{*0}(890){\ensuremath{\pi}}^{+}$ systems produced in reaction ${K}^{+}p\ensuremath{\rightarrow}{K}^{+}p{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}$ at 12.7 GeV/c. Comparisons between these data two diffractive models are presented
The production of the ${\ensuremath{\rho}}^{0}$, ${f}^{0}$, ${g}^{0}$, ${\ensuremath{\eta}}^{0}$, and ${\ensuremath{\omega}}^{0}$ bosons in pseudo-two-body final state with ${\ensuremath{\Delta}}^{++}(1236)$ baryon is studied. cross sections their $t$ dependence are discussed. $s$ ${\ensuremath{\Delta}}^{++}{\ensuremath{\rho}}^{0}$ ${\ensuremath{\Delta}}^{++}{\ensuremath{\omega}}^{0}$ states fitted expression $\ensuremath{\sigma}=k{(\frac{p}{{p}_{0}})}^{\ensuremath{-}n}$ yields values $n$...
We present the decay characteristics of low-mass ${Q}^{+}$ enhancement in ${(K\ensuremath{\pi}\ensuremath{\pi})}^{+}$ system which is produced reaction ${K}^{+}p\ensuremath{\rightarrow}{(K\ensuremath{\pi}\ensuremath{\pi})}^{+}p$ at 12.7 GeV/c. When treated as a single resonance, this has properties expected for strange member an $\mathrm{SU}(3)$ meson octet with ${J}^{\mathrm{PC}}={1}^{++}$. The resonance position and width $Q$ are, respectively, 1260\ifmmode\pm\else\textpm\fi{}20...
We observed statistically significant peaks in the charged and neutral three-pion mass spectra at position of ${A}_{1}$ reactions ${K}^{+}p\ensuremath{\rightarrow}{K}^{0,+}p{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{+,0}$ 12.7 GeV/c. discuss possible interpretation these peaks.
The hydroxyl radical (OH) is the most important daytime oxidant in troposphere, initiating chemical degradation of volatile organic compounds (VOCs) and hence contributing to formation secondary pollutants such as ozone (O3). In oxidation process VOCs, peroxy radicals (RO2) hydroperoxy (HO2) are formed. polluted areas, characterised by presence nitric oxide (NO), OH regenerated reaction HO2 with NO, enhancing atmospheric oxidation. Ozone mainly produced from photolysis nitrogen dioxide (NO2)...
Ozone (O3) is a criteria air pollutant in the troposphere and powerful oxidant that damages cellular tissue along our respiratory tract, causing distress, crops other plants, decreasing primary productivity environment. O3 also greenhouse gas responsible for ~12% of anthropogenic global warming since 1750. Unlike pollutants have major emission sources, entirely secondary has complicated non-linear dependence on its precursors nitrogen oxides (NOx) volatile organic compounds (VOCs). For...
Abstract. Hydroxyl radical OH reactivity, which is the inverse lifetime of radical, provides information on burden air pollutants, since almost all pollutants react with OH. reactivity measurements from field experiments can help to identify gaps in measurement individual reactants and serve as a proxy for potential formation secondary including ozone particles. However, not regularly measured specifically airborne platforms due technical complexity instruments and/or need careful...
Abstract. The oxidation of sabinene by the hydroxyl radical (OH) and ozone (O3) was investigated under atmospherically relevant conditions in atmospheric simulation chamber SAPHIR (Simulation Atmospheric Photochemistry In a Large Reaction Chamber) at Forschungszentrum Jülich, Germany. rate coefficients reactions with OH O3 were determined. temperature dependence between 284 to 340 K coefficient reaction OH, kSAB+OH, measured for first time using an reactivity instrument, resulting Arrhenius...
On
Abstract The dipole response of the proton-magic nucleus $${}^{124}\hbox {Sn}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msup><mml:mrow/><mml:mn>124</mml:mn></mml:msup><mml:mtext>Sn</mml:mtext></mml:mrow></mml:math> was previously investigated with electromagnetic and hadronic probes. Different responses were observed revealing so-called isospin splitting Pygmy Dipole Resonance (PDR). Here we present results a new study using inelastic proton scattering at low...
Abstract. The oxidation of sabinene by the hydroxyl radical (OH) and ozone (O3) was investigated under atmospherically relevant conditions in atmospheric simulation chamber SAPHIR at Forschungszentrum Jülich, Germany. rate constants reactions with OH O3 were determined. temperature dependence between 284 K to 340 constant reaction OH, kSAB+OH, measured for first time using an reactivity instrument, resulting Arrhenius expression (1.67 ± 0.16) × 10−11 exp((575 30) T−1) cm3 s−1. values agree...