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Indoor air quality was characterized in 10 recently built energy-efficient French schools during two periods of 4.5 days. Carbon dioxide time-resolved measurements during occupancy clearly highlight the key role of the ventilation rate (scheduled or occupancy indexed), especially in this type of building, which was tightly sealed and equipped with a(More)
The absorption spectrum of CH3O2 radicals and CH3I molecules has been measured in the range 7473-7497 cm(-1). CH3O2 radicals have been generated by 248 nm laser photolysis of CH3I in the presence of O2, and the relative absorption has been measured by time-resolved continuous-wave cavity ring-down spectroscopy (cw-CRDS). Calibration of the relative(More)
•OH and •HO2 radicals are known to be the key species in the development of ignition. A direct measurement of these radicals under low-temperature oxidation conditions (T = 550-1,000 K) has been achieved by coupling a technique named fluorescence assay by gas expansion, an experimental technique designed for the quantification of these radicals in the free(More)
The energy dependence of HO(2) radical formation from the irradiation of benzene (C(6)H(6)) in the presence of oxygen (O(2)) at 248 nm is studied. We investigate the origin of the HO(2) radicals, that is, whether they originate from the reaction of O(2) with products obtained by one- or two-photon excitation of C(6)H(6). The concentration-time profiles of(More)
The photolysis of HONO has been found to be the oxidation driver through OH formation in the indoor air measurement campaign SURFin, an extensive campaign carried out in July 2012 in a classroom in Marseille. In this study, the INCA-Indoor model is used to evaluate different HONO formation mechanisms that have been used previously in indoor air quality(More)
A new FAGE setup has recently been built at the University of Lille, France. It permits the quantification of OH and HO2 in the atmosphere with a detection limit of 3 x 105 molecules/(cm3 x min) for OH and 1 x 10(6) molecules/(cm3 x min) for HO2. Its coupling to a photolysis cell enables the measurement of the total reactivity of the hydroxyl radical in(More)
Radical quantum yields have been measured following the 248 nm photolysis of acetaldehyde, CH3CHO. HCO radical and H atom yields have been quantified by time resolved continuous wave Cavity Ring Down Spectroscopy in the near infrared following their conversion to HO2 radicals by reaction with O2. The CH3 radical yield has been determined using the same(More)
A novel instrument for measuring total HO2 reactivity in the troposphere was successfully developed using a laser-flash photolysis and laser-induced fluorescence detection technique. Validation and testing were conducted through kinetic measurements of the reaction of HO2 radicals with NO2, and the results were found to be in good agreement with recent(More)
We present the coupling of a jet-stirred reactor to detection by cw-CRDS in the near infrared and first results obtained during the oxidation of methane. The mixture is rapidly expanded from the jet-stirred reactor into a 80 cm-long cw-CRDS cell maintained at a the pressure around 1.33 kPa, thus freezing the reaction and decreasing pressure broadening of(More)
The first reliable quantification of hydrogen peroxide (H(2)O(2)) formed during the low-temperature oxidation of an organic compound has been achieved thanks to a new system that couples a jet stirred reactor to a detection by continuous wave cavity ring-down spectroscopy (cw-CRDS) in the near-infrared. The quantification of this key compound for(More)