The formation of toxic heavy clouds as a result of sudden accidental releases from mobile containers, such as road tankers or railway tank cars, may occur inside urban areas so the problem arises of their consequences evaluation. Due to the semi-confined nature of the dispersion site simplified models may often be inappropriate. As an alternative, computational fluid dynamics (CFD) has the pote...

Since municipal solid waste (MSW) landfills emit significant amounts of methane, a potent greenhouse gas, there is considerable interest in quantifying surficial methane emissions from landfills. The authors propose a new and easier method by which to estimate methane emissions. The technique uses hundreds of ambient air VOC measurements taken within a landfill, as receptors, and solves the sta...

We analyzed Chandra observations of three gravitational lenses, SBS 0909+523, FBQS 0951+2635, and B 1152+199, to measure the differential X-ray absorption and the dust-to-gas ratio of the lens galaxies. We successfully detected the differential X-ray absorption in SBS 0909+523 and B 1152+199, and failed to detect it in FBQS 0951+2635 due to the dramatic drop in its flux from the ROSAT epoch. Th...

In the present study, a heterogeneous and homogeneous gas flow dispersion model for simulation and optimization of a large-scale catalytic slurry reactor for the direct synthesis of dimethyl ether (DME) from synthesis gas (syngas) and CO2, using a churn-turbulent regime was developed. In the heterogeneous flow model, the gas phase was distributed into two bubble phases including small and large...

Accidental or intentional releases of contaminants into the atmosphere pose risks to human health, the environment, the economy, and national security. In some cases there may be a single release from an unknown source, while in other cases there are fugitive emissions from multiple sources. The need to locate and characterize the sources efficiently whether it be the urgent need to evacuate or...

We present the CO J=6–5, 4–3, and 3–2 spectra from the blueshifted gas of the outflow driven by the low-mass class 0 protostar in the L1157 dark cloud. Strong submillimeter CO emission lines with Tmb > 30 K have been detected at 63 (∼0.13 pc) south from the protostar. It is remarkable that the blue wings in the submillimeter lines are stronger by a factor of 3–4 than that of the CO J=1–0 emissi...

Reliable thermochemical measurements and theoretical predictions for reactions involving large transition metal complexes in which long-range intramolecular London dispersion interactions contribute significantly to their stabilization are still a challenge, particularly for reactions in solution. As an illustrative and chemically important example, two reactions are investigated where a large ...