The Experts below are selected from a list of 249 Experts worldwide ranked by ideXlab platform
Anu Dudhia - One of the best experts on this subject based on the ideXlab platform.
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Measurement from sun-synchronous orbit of a Reaction Rate controlling the diurnal NO x cycle in the stratosphere
Atmospheric Chemistry and Physics, 2011Co-Authors: Joanne Walker, Anu DudhiaAbstract:Abstract. A Reaction Rate associated with the nighttime formation of an important diurnally varying species, N 2 O 5 , is determined from MIPAS-ENVISAT. During the day, photolysis of N 2 O 5 in the stratosphere contributes to nitrogen-catalysed ozone destruction. However, at night concentrations of N 2 O 5 increase, temporarily sequestering reactive NO x NO and NO 2 in a natural cycle which regulates the majority of stratospheric ozone. In this paper, the Reaction Rate controlling the formation of N 2 O 5 is determined from this instrument for the first time. The Observed Reaction Rate is compared to the currently accepted Rate determined from laboratory measurements. Good agreement is obtained between the Observed and accepted experimental Reaction Rates within the error bars.
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Measurement from sun-synchronous orbit of a Reaction Rate controlling the diurnal NO<sub>x</sub> cycle in the stratosphere
2010Co-Authors: J. C. Walker, Anu DudhiaAbstract:Abstract. A Reaction Rate associated with the nighttime formation of an important diurnally varying species, N2O5, is determined from MIPAS-ENVISAT. During the day, photolysis of N2O5 in the stratosphere contributes to nitrogen-catalysed ozone destruction. However, at night concentrations of N2O5 increase, temporarily sequestering reactive NOx (NO + NO2), in a natural cycle which regulates the majority of stratospheric ozone. In this paper, the Reaction Rate controlling the formation of N2O5 is determined for the first time from an instrument aboard a sun-synchronous platform. The Observed Reaction Rate is compared to the currently accepted Rate determined from laboratory measurements. Good agreement is obtained between the Observed and experimental Reaction Rates down to temperatures as low as 205 K for the first time.
A.p. Watkinson - One of the best experts on this subject based on the ideXlab platform.
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Operating conditions for oil shale thermogravimetry
Powder Technology, 1999Co-Authors: A.c.l. Lisboa, A.p. WatkinsonAbstract:Standard thermogravimetric apparatuses offer highly desirable conditions for the study of the chemical kinetics of oil shale pyrolysis and combustion, such as controlled temperature and simultaneous weighing of the sample. The thermogravimetric analyses must be carried out in such conditions that the Observed Reaction Rate is identical to the Rate of the chemical kinetics. This study investigated the effects of key parameters which could affect this identity, such as: the gas flow Rate, the gas purity, the gas nature, the particle sizes and sample sizes. The paper suggests values for these parameters.
Gorazd Bercic - One of the best experts on this subject based on the ideXlab platform.
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influence of operating conditions on the Observed Reaction Rate in the single channel monolith reactor
Catalysis Today, 2001Co-Authors: Gorazd BercicAbstract:Abstract The catalytic hydrogenation of nitrobenzoic acid (NBA) to the aminobenzoic acid was used as a model Reaction for a quantitative study of influences of the operating conditions on the Observed Reaction Rate in a single channel monolith reactor opeRated in Taylor flow regime. A simple mathematical model was derived and used for the analysis of hydrogenation experiments carried out in batch mode. Results showed that in the investigated concentration range of NBA, i.e. 0.0005–0.02 mol/l and under the hydrogen pressure of 1 bar, the Observed Reaction Rate is considerably limited by mass transport. At higher concentrations of NBA, the Reaction is controlled by the hydrogen mass transport while at lower concentrations the mass transport of NBA is dominant. The analysis of experimental results, which were obtained when the length of gas bubbles and liquid slugs were varied, showed that the Reaction took place in the thin liquid film surrounding the gas bubble. The liquid slug serves as exchanger of reactants and Reaction products between bulk liquid slug and liquid film surrounding the catalyst surface.
Joanne Walker - One of the best experts on this subject based on the ideXlab platform.
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Measurement from sun-synchronous orbit of a Reaction Rate controlling the diurnal NO x cycle in the stratosphere
Atmospheric Chemistry and Physics, 2011Co-Authors: Joanne Walker, Anu DudhiaAbstract:Abstract. A Reaction Rate associated with the nighttime formation of an important diurnally varying species, N 2 O 5 , is determined from MIPAS-ENVISAT. During the day, photolysis of N 2 O 5 in the stratosphere contributes to nitrogen-catalysed ozone destruction. However, at night concentrations of N 2 O 5 increase, temporarily sequestering reactive NO x NO and NO 2 in a natural cycle which regulates the majority of stratospheric ozone. In this paper, the Reaction Rate controlling the formation of N 2 O 5 is determined from this instrument for the first time. The Observed Reaction Rate is compared to the currently accepted Rate determined from laboratory measurements. Good agreement is obtained between the Observed and accepted experimental Reaction Rates within the error bars.
A.c.l. Lisboa - One of the best experts on this subject based on the ideXlab platform.
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Operating conditions for oil shale thermogravimetry
Powder Technology, 1999Co-Authors: A.c.l. Lisboa, A.p. WatkinsonAbstract:Standard thermogravimetric apparatuses offer highly desirable conditions for the study of the chemical kinetics of oil shale pyrolysis and combustion, such as controlled temperature and simultaneous weighing of the sample. The thermogravimetric analyses must be carried out in such conditions that the Observed Reaction Rate is identical to the Rate of the chemical kinetics. This study investigated the effects of key parameters which could affect this identity, such as: the gas flow Rate, the gas purity, the gas nature, the particle sizes and sample sizes. The paper suggests values for these parameters.
