We report the formation of a crater at the free surface of an immersed granular bed, locally crossed by an ascending gas flow. In two dimensions, the crater consists of two piles which develop around the location of the gas emission. We observe that the typical size of the crater increases logarithmically with time, independently of the gas emission dynamics. We describe the related granular fl...

We use a high-resolution cosmological simulation to predict the distribution of H I Lyα emission from the lowredshift (z . 0.5) intergalactic medium (IGM). Our simulation can be used to reliably compute the emission from optically thin regions of the IGM but not that of self-shielded gas. We therefore consider several models that bracket the expected emission from self-shielded regions. Most ga...

We present the first fully sampled map of CO (1-0) emission from M82 covering the entire galaxy. Our map contains a ∼ 12 ×15 kpc area. We find that extraplanar CO emission, previously reported at short distances above the galactic plane, extends to heights of up to 6 kpc above the disk. Some of this emission is associated with tidal arms seen in HI, implying either that M82 contained substantia...

A life-cycle assessment (LCA) of corn ethanol was conducted to determine the reduction in the life-cycle greenhouse gas (GHG) emissions for corn ethanol compared to gasoline by integrating biomass fuels to replace fossil fuels (natural gas and grid electricity) in a U.S. Midwest dry-grind corn ethanol plant producing 0.19 hm y 1 of denatured ethanol. The biomass fuels studied are corn stover an...

More technology implies higher welfare. Therefore, it is individually rational to cooperate on technological development. It is not individually rational cooperate on greenhouse gas emission reduction. If technology cooperation only comes with cooperation on emission reduction, incentives to free ride on the emission reduction agreement are reduced. However, countries would prefer to cooperate ...

The results of a CO line survey in central cluster galaxies with cooling flows are presented. Cold molecular gas is detected with the IRAM 30m telescope, through CO(1-0) and CO(2-1) emission lines in 6-10 among 32 galaxies. The corresponding gas masses are between 3.10 and 4.10 M . These results are in agreement with recent CO detections by Edge (2001). A strong correlation between the CO emiss...

We study the effect of non-relativistic, thermal matter in the jets of active galaxies (AGN) on the low-frequency non-thermal emission and the variability thereof. In matter-dominated jets, sizable quantities of gas should exist, in particular in the compression zones near the collision fronts that are an implicit ingredient of Fermi-type particle acceleration scenarios. Non-relativistic therma...

The prototype compact group known as Stephan's Quintet (SQ) was observed with XMM-Newton in order to complement the excellent resolution of Chandra with high sensitivity to extended emission. SQ is a dynamic environment whose main effect, at both X-ray and optical wavelengths, appears to be ISM stripping. This is manifested by: 1) secular evolution of morphological types towards earlier types a...

One of the main factors contributing to greenhouse gas emissions in the environment is the production of pollutant gases in landfills. Collecting the landfill gases (LFG) effectively reduces the emission of gasses from the landfill site. A precise collection system for LFG can create the potential for energy generation in addition to emissions reduction. However, in Iran, the implementation of ...

The Persian Gulf States (Bahrain. Iran, Iraq, Kuwait, Qatar, Saudi Arabia and United Arab Emirate) have dominated the oil and gas sector since the discovery of oil in the region. They are the world largest producers of crude oil, producing about 35 and 25 percent of the world natural gas and crude oil respectively. The use of fossil fuels is directly linked to the release of CO2 into...