Manuel Krapf
A5004778219- Atmospheric chemistry and aerosols
- Air Quality and Health Impacts
- Air Quality Monitoring and Forecasting
- Atmospheric Ozone and Climate
- Vehicle emissions and performance
- Atmospheric aerosols and clouds
- Energy and Environment Impacts
- Odor and Emission Control Technologies
- Fibromyalgia and Chronic Fatigue Syndrome Research
- Infrared Thermography in Medicine
- Pain Management and Treatment
- Myofascial pain diagnosis and treatment
- Musculoskeletal pain and rehabilitation
- Muscle activation and electromyography studies
Paul Scherrer Institute
2015-2019
Hochrhein Institut für Rehabilitationsforschung
1992-1997
Abstract About half of present-day cloud condensation nuclei originate from atmospheric nucleation, frequently appearing as a burst new particles near midday 1 . Atmospheric observations show that the growth rate often accelerates when diameter is between one and ten nanometres 2,3 In this critical size range, are most likely to be lost by coagulation with pre-existing 4 , thereby failing form typically 50 100 across. Sulfuric acid vapour involved in nucleation but too scarce explain...
Abstract Atmospheric aerosols and their effect on clouds are thought to be important for anthropogenic radiative forcing of the climate, yet remain poorly understood 1 . Globally, around half cloud condensation nuclei originate from nucleation atmospheric vapours 2 It is that sulfuric acid essential initiate most particle formation in atmosphere 3,4 , ions have a relatively minor role 5 Some laboratory studies, however, reported organic without intentional addition acid, although...
Significance A mechanism for the formation of atmospheric aerosols via gas to particle conversion highly oxidized organic molecules is found be dominant aerosol process in preindustrial boundary layer over land. The inclusion this a global model raises baseline concentrations and could lead reduction 27% estimates anthropogenic radiative forcing.
Abstract. Residential wood burning contributes to the total atmospheric aerosol burden; however, large uncertainties remain in magnitude and characteristics of products. Primary emissions are influenced by a variety parameters, including appliance type, burner load type. In addition directly emitted particles, previous laboratory studies have shown that oxidation gas-phase produces compounds with sufficiently low volatility readily partition forming considerable quantities secondary organic...
Abstract Particulate matter (PM) pollution is a leading cause of premature death, particularly in those with pre-existing lung disease. A causative link between particle properties and adverse health effects remains unestablished mainly due to complex variable physico-chemical PM parameters. Controlled laboratory experiments are required. Generating atmospherically realistic aerosols performing cell-exposure studies at relevant particle-doses challenging. Here we examine gasoline-exhaust...
Abstract. Secondary organic aerosol (SOA) yields from the photo-oxidation of α-pinene were investigated in smog chamber (SC) experiments at low (23–29 %) and high (60–69 relative humidity (RH), various NOx ∕ VOC ratios (0.04–3.8) with different seed chemical compositions (acidic to neutralized sulfate-containing or hydrophobic organic). A combination a scanning mobility particle sizer an Aerodyne high-resolution time-of-flight mass spectrometer was used determine SOA concentration...
Abstract. Reactive oxygen species (ROS) are believed to contribute the adverse health effects of aerosols. This may happen by inhaled particle-bound (exogenic) ROS (PB-ROS) or formed within respiratory tract certain aerosol components (endogenic ROS). We investigated chemical composition aerosols and their exogenic content at two contrasting locations Beijing (China) Bern (Switzerland). apportioned ambient organic different sources attributed observed water-soluble PB-ROS them. The...
Abstract. We report the first measurements of HO2 uptake coefficients, γ, for secondary organic aerosol (SOA) particles and well-studied model compound sucrose which we doped with copper(II). Above 65 % relative humidity (RH), γ copper(II)-doped equalled surface mass accommodation coefficient α = 0.22 ± 0.06, but it decreased to 0.012 0.007 upon decreasing RH 17 %. The trend can be explained by an increase in viscosity contribution a reaction, as demonstrated using kinetic multilayer bulk...
Abstract. This study presents the difference between oxidised organic compounds formed by α-pinene oxidation under various conditions in CLOUD environmental chamber: (1) pure ozonolysis (in presence of hydrogen as hydroxyl radical (OH) scavenger) and (2) OH (initiated nitrous acid (HONO) photolysis ultraviolet light) absence ozone. We discuss results from three Atmospheric Pressure interface Time-of-Flight (APi-TOF) mass spectrometers measuring simultaneously composition naturally charged...
Particulate matter from direct wood combustion emissions and their subsequent atmospheric oxidation affects airway epithelia of specific health status due to a combined effect several chemical constituents.
Abstract. Residential wood burning contributes significantly to the total atmospheric aerosol burden; however, large uncertainties remain in magnitude and characteristics of products. Primary emissions are influenced by a variety parameters, including appliance type, burner load type. In addition directly emitted particles, previous laboratory studies have shown that oxidation gas phase produces compounds with sufficiently low volatility readily partition forming significant quantities...
Abstract. Secondary organic aerosol (SOA) yields from the photooxidation of α-pinene were investigated in smog chamber (SC) experiments at low (23–29 %) and high (60–69 relative humidity (RH), various NOx/VOC ratios (0.04–3.8) with different seed chemical compositions (acidic to neutralized sulfate-containing or hydrophobic organic). A combination a scanning mobility particle sizer an Aerodyne resolution time-of-flight mass spectrometer was used determine SOA concentration composition. We...
Abstract. We report the first measurements of HO2 uptake coefficients, γ, for secondary organic aerosol particles (SOA) and well-studied model compound sucrose which was doped with copper. Above 65 % relative humidity (RH), γ copper equalled surface mass accommodation coefficient α = 0.22 ± 0.06 but decreased to 0.012 0.007 upon decreasing RH 17 %. The trend can be explained by an increase in viscosity, as demonstrated using kinetic multi-layer bulk chemistry (KM-SUB). SOA from two different...
Abstract. This study presents the difference between oxidised organic compounds formed by α-pinene ozonolysis and hydroxyl radical (OH) oxidation in CLOUD environmental chamber. The results from three Atmospheric Pressure interface Time-Of-Flight (APi-TOF) mass spectrometers measuring simultaneously composition of naturally charged, as well neutral species (via chemical ionisation with nitrate) are discussed. Natural takes place chamber form clusters nitrate, bisulphate, bisulphate/sulphuric...
Abstract. Reactive oxygen species (ROS) are believed to contribute the adverse health effects of aerosols. This may happen by inhaled particle-bound (exogenic) ROS (PB-ROS) or formed within respiratory tract certain aerosol components (endogenic ROS). We investigated chemical composition aerosols and their exogenic content at two contrasting locations Beijing (China) Bern (Switzerland). apportioned ambient organic different sources attributed observed PB-ROS them. The oxygenated (OOA, a...