Gas infiltration

Indoor radon in most houses come primarily from soil gas infiltrating into the house because of pressure-driven flow. The radon decays into a series of decay products to which most of the health effects are attributed. These decay products begin attached to ultrafine particles that either plateout on surfaces such as walls, furniture, etc., or become attached to larger particles that are present in the indoor air. The nature of those particles depends on the kinds of sources that exist in the house such as smokers, gas stoves, etc. 

In this case, the combustion front propagates due to the interaction between the solid reactant and the gas infiltrated to the reaction zone from the surrounding atmosphere (see Section IV,D). For metal-nitrogen reactions, this type of combustion was observed for low initial sample density (-0.2) in the Ta-N2 system, where the metal does not melt in the combustion wave (Pityulin et al, 1979 Ku-... 

Nitriding. The production of nitrides from a porous metal shape, by direct reaction with nitrogen gas infiltrating the pores. 

ASHRAE Fundamentals Handbook, ch. 25 Ventilation and Infiltration. Atlanta, GA American Society of Heating, Refrigeration and Air-Conditioning Engineers, 1997. 

Induced draft fans (ID fans) are located near the end of the flue-gas path and provide a negative static pressure below that of atmospheric pressure (creating a partial vacuum). This induces outside air to infiltrate any openings in the boiler. 

Kanda H, Tateya S, Tamori Y, Kotani K, Hiasa K, Kitazawa R, Kitazawa S, Miyachi H, Maeda S, Egashira K, Kasuga M (2006) MCP-1 contributes to macrophage infiltration into adipose tissue, insulin resistance, and hepatic steatosis in obesity. J Qin Invest 116 1494-1505 Kaul M, Garden GA, Lipton SA (2001) Pathways to neuronal injury and apoptosis in HIV-associated dementia. Nature 410 988-994... 

Lung Fever, impaired gas exchange, SOB, malaise, anxiety Decreased FEV, infiltrate on CXR, biopsy positive for lymphocytic infiltration... 

This section describes the elements in a closure or cap system of a completed landfill, including flexible membrane caps (FMCs), SWCR systems, gas control layers, biotic barriers, and vegetative top covers. It also discusses infiltration, erosion control, and long-term aesthetic concerns associated with securing a completed landfill. 

The pores of the silica template can be filled by carbon from a gas or a liquid phase. One may consider an insertion of pyrolytic carbon from the thermal decomposition of propylene or by an aqueous solution of sucrose, which after elimination of water requires a carbonization step at 900°C. The carbon infiltration is followed by the dissolution of silica by HF. The main attribute of template carbons is their well sized pores defined by the wall thickness of the silica matrix. Application of such highly ordered materials allows an exact screening of pores adapted for efficient charging of the electrical double layer. The electrochemical performance of capacitor electrodes prepared from the various template carbons have been determined and are tentatively correlated with their structural and microtextural characteristics. 

The alcohol evaporation under vacuum, the treatment of cells and microcapsules by silica precursor supplied by gas carrier and infiltration of silica nanoparticles, whose are discussed above, are the examples of such modified approaches. There are two original methods whose would be well to consider. 

In most cases, the radon infiltrates from the soil into the building under the influence of a pressure differential caused by the structure itself. The amount of radon that results is dependent on the amount of radon in the soil gas, the ability of the soil gas to move through the soil, and the characteristics of the building that provides the driving force and entry pathways. 

Ericson, S.-O. and H. Schmied, Modified Design in New Construction Prevents Infiltration of Soil Gas Carrying Radon, this volume (1987). 

Modified Design in New Construction Prevents Infiltration of Soil Gas That Carries Radon... 

Radon from the soil enters into buildings by convective flow of soil gas. Transport by diffusion is normally insignificant. In houses with very high radon concentration, diffusion need not be considered because it can only provide an insignificant fraction of the source strength. There are three conditions necessary for infiltration of soil gas containing radon into the building from the soil ... 

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