Generalized Einstein B coefficients for coherently driven closed three-level systems are introduced by means of the quantum-jump technique. The nonreciprocity between stimulated emission and absorption for both one-photon and two-photon gain and loss processes has been studied and quantified in terms of the rates of the particular incoherent processes present in each three-level system. Some ge...

This paper presents a sensitivity analysis and an evaluation of the semi-empirical model known as Operational Street Pollution Model (OSPM). The model is capable of calculating airborne concentrations of exhaust gases emitted by vehicles, within a street canyon. OSPM has been extensively evaluated using data collected over a two year period (1994-1995), during a monitoring campaign carried out ...

In this study the sensitivity of the model performance of the chemistry transport model (CTM) LOTOSEUROS to the description of the temporal variability of emissions was investigated. Currently the temporal release of anthropogenic emissions is described by European average diurnal, weekly and seasonal time profiles per sector. These default time profiles largely neglect the variation of emissio...

In this study, Thermal expansion coefficient (TEC) variation of Ln0.6Sr0.4Co0.2M0.8O3−δ (Ln=La,Nd,Sm and M= Fe,Ni,Mn) perovskite oxide have been evalouated. Different compounds have been prepared and thermal expansion coefficient have been meseaured in different temperature by means of dilatometer analysis. Structural parameters of compounds have been  determined by X-ray diffraction and Field ...

the gaseous composition of the earth's atmosphere is changing at an accelerated rate because of the influence of human activities. different factors can cause increasing air contamination such as co2. understanding factors affecting atmosphere gaseous change is important for management and reducing air contaminants. the aim of this paper is to investigate factors affecting on co2 emission ...

Transparent Ce:YAG ceramics were synthesized from the Ce:YAG powder which was produced by co-preparation method of the hydroxides. The Ce:YAG ceramics exhibit a broad emission band peaked at 530 nm due to the 5d→4f transition of Ce 3+ . The transmittances of the samples obtained were 70 ~ 87 % at 800 nm. The absorption coefficient and emission intensity of Ce 3+ were increased with the increase...