Compressive strengthIn mechanics, compressive strength (or compression strength) is the capacity of a material or structure to withstand loads tending to reduce size (as opposed to tensile strength which withstands loads tending to elongate). In other words, compressive strength resists compression (being pushed together), whereas tensile strength resists tension (being pulled apart). In the study of strength of materials, tensile strength, compressive strength, and shear strength can be analyzed independently.
WallA wall is a structure and a surface that defines an area; carries a load; provides security, shelter, or soundproofing; or, is decorative. There are many kinds of walls, including: Walls in buildings that form a fundamental part of the superstructure or separate interior rooms, sometimes for fire safety Glass walls (a wall in which the primary structure is made of glass; does not include openings within walls that have glass coverings: these are windows) Border barriers between countries Brick walls Defensive walls in fortifications Permanent, solid fences Retaining walls, which hold back dirt, stone, water, or noise sound Stone walls Walls that protect from oceans (seawalls) or rivers (levees) The term wall comes from Latin vallum meaning ".
SpermatogenesisSpermatogenesis is the process by which haploid spermatozoa develop from germ cells in the seminiferous tubules of the testis. This process starts with the mitotic division of the stem cells located close to the basement membrane of the tubules. These cells are called spermatogonial stem cells. The mitotic division of these produces two types of cells. Type A cells replenish the stem cells, and type B cells differentiate into primary spermatocytes.
CladogenesisCladogenesis is an evolutionary splitting of a parent species into two distinct species, forming a clade. This event usually occurs when a few organisms end up in new, often distant areas or when environmental changes cause several extinctions, opening up ecological niches for the survivors and causing population bottlenecks and founder effects changing allele frequencies of diverging populations compared to their ancestral population.
