### activity | penetration:

Infiltration
* Some infiltrations create soil conditions
  - reduce runoff
* amounts to a rate of heat loss.
* are penetrations.
* become problems.
* component of the general mass balance hydrologic budget.
* enables water to saturate the soil, causing it to become fluid and potentially mobile.
* form of maneuver in the offense.
* generally refers to cold air during the winter and hot air during the summer.
* happens when water soaks into the soil from the ground level.
* increases with fracture density.
* is an accumulation of fluids in the tissue surrounding the venipuncture site
  - e-zine about exploring the forbidden domains of the urban landscape
  - controlled by soil texture, soil structure, vegetation and soil moisture status
  - defined in SWAT as precipitation minus runoff
  - done on ice to prevent the gelatin from warming
  - groundwater that enters sanitary sewers through leaks in pipes
  - important to reducing runoff and storing water in the soil for plant growth
  - increased by ground cover
  - most effective in relatively permeable soils
  - one of the major sources of heat gain into buildings
* is rapid when the soil is dry and cracked, but very slow when it is wet
  - dry and cracked, but very slow when the soil is moist
  - dry and cracked, but very slow when the soil is wet
* is the downward movement of water from the land surface into the ground
  - exchange of inside air with outside air
  - flow of water from the ground surface into the ground
  - leakage of air between and around window frame and glazing components
  - leaking of ground or surface water into a properly constructed sewer system
  - movement of moisture from the atmosphere into and through the soil surface
* is the movement of water from precipitation into the soil layer
  - into the ground from the surface
* is the process by which water enters the soil
  - on the ground surface enters the soil
* is the process of water being soaked into the ground
  - entering the soil surface
  - where water seeps into the ground
  - rate at which water gets through the surface and into the soil
  - when water soaks into the ground
* moves downward into the deeper parts of an aquifer in a recharge area
  - into the soil profile where it is routed through the soil layers
* occurs due to joints and cracks in piping, which increases with pipe age
  - more rapidly at the beginning of a ponding event and slows down over time
* occurs when groundwater enters the sanitary sewer system through defects in the system
  - precipitation seeps into the ground
  - water falls back to Earth, where some of it soaks into the ground
  - wind blows cold air into the house and forces hot air out
* problem in both the summer and the winter.
* refers to the abnormal presence of granulomas in the lung tissue
  - leakage of undesired air into the home
  - water that penetrates into the surface of soil
* requires immersing tissues in two changes of melted paraffin.
* result of negative pressures in the building or positive pressure on the outside.
* tends to increase with porosity.
* uses a bucket model to distribute water through the soil layers.
* varies both spatially and temporally due to a number of environmental factors.

### activity | penetration | infiltration:

Air infiltration
* is recognized as an important factor in building energy conservation.
* major cause of energy loss.
* occurs when air leaks through gaps in the insulation.

Direct infiltration
* includes the use of infiltration trenches or infiltration basins.
* is by far the most common cause of neoplastic plexopathy.

Water infiltration
* Some water infiltrations reduce runoff.
* happens with any type of mining.

Internet penetration
* has the potential to vastly accelerate access to information.
* increases with higher household income and education levels.