Search results
Results from the WOW.Com Content Network
Transcatheter aortic valve replacement (TAVR) is the implantation of the aortic valve of the heart through the blood vessels without actual removal of the native valve (as opposed to the aortic valve replacement by open heart surgery, surgical aortic valve replacement, AVR).
Aortic valve replacement is a cardiac surgery procedure whereby a failing aortic valve is replaced with an artificial heart valve.The aortic valve may need to be replaced because of aortic regurgitation (back flow), or if the valve is narrowed by stenosis.
Soil formation, also known as pedogenesis, is the process of soil genesis as regulated by the effects of place, environment, and history. Biogeochemical processes act to both create and destroy order ( anisotropy ) within soils.
Since the origin of agriculture, humans have understood that soils contain different properties which affect their ability to grow crops. [4] However, soil science did not become its own scientific discipline until the 19th century, and even then early soil scientists were broadly grouped as either "agro-chemists" or "agro-geologists" due to the enduring strong ties of soil to agriculture.
Podzolization (or Podsolization [9]) is a complex soil formation process by which dissolved organic matter and ions of iron and aluminium, released through weathering of various minerals, form organo-mineral complexes and are moved from the upper parts of the soil profile and deposit in the deeper parts of soil.
Joseph E. Bavaria, M.D., FACS, FRCS (Edin) ad hom, (born 1957) is an American cardiothoracic surgeon [6] a professor of surgery at the University of Pennsylvania and Director of its Thoracic Aortic Surgery Program.
The information in a soil survey can be used by farmers and ranchers to help determine whether a particular soil type is suited for crops or livestock and what type of soil management might be required. An architect or engineer might use the engineering properties of a soil to determine whether it is suitable for a certain type of construction.
Soil is created from rock that has been chemically or physically weathered, transported, deposited and precipitated. [2] Soil particles include sand , silt and clay . Sand particles are the largest at 2 to 0.05 millimetres (0.0787 to 0.0020 in) in diameter and clay the smallest at less than 0.002 millimetres (7.9 × 10 −5 in) in diameter. [ 3 ]