An extract on #ayakkab
Bacteria such as Bacillus pasteurii, Bacillus pseudofirmus, Bacillus cohnii, Sporosarcina pasteuri, and Arthrobacter crystallopoietes increase the compression strength of concrete through their biomass. Not all bacteria increase the strength of concrete significantly with their biomass. Bacillus sp. CT-5. can reduce corrosion of reinforcement in reinforced concrete by up to four times. Sporosarcina pasteurii reduces water and chloride permeability. B. pasteurii increases resistance to acid. Bacillus pasteurii and B. sphaericuscan induce calcium carbonate precipitation in the surface of cracks, adding compression strength.
Concrete roads are more fuel efficient to drive on, more reflective and last significantly longer than other paving surfaces, yet have a much smaller market share than other paving solutions. Modern-paving methods and design practices have changed the economics of concrete paving, so that a well-designed and placed concrete pavement will be less expensive on initial costs and significantly less expensive over the life cycle. Another major benefit is that pervious concrete can be used, which eliminates the need to place storm drains near the road, and reducing the need for slightly sloped roadway to help rainwater to run off. No longer requiring discarding rainwater through use of drains also means that less electricity is needed (more pumping is otherwise needed in the water-distribution system), and no rainwater gets polluted as it no longer mixes with polluted water. Rather, it is immediately absorbed by the ground.
The male condom should be rolled onto an erect penis before intercourse and works by blocking semen from entering the body of a sexual partner. Male condoms are typically made from latex and less commonly from polyurethane or lamb intestine. Male condoms have the advantages of ease of use, easy to access, and few side effects. In those with a latex allergy a polyurethane or other synthetic version should be used. Female condoms are typically made from polyurethane and may be used multiple times.
Condoms as a method of preventing STIs have been used since at least 1564. Rubber condoms become available in 1855 followed by latex condoms in the 1920s. They are on the World Health Organization's List of Essential Medicines, the most effective and safe medicines needed in a health system. The wholesale cost in the developing world is about 0.03 to 0.08 USD each. In the United States condoms usually cost less than 1.00 USD. Globally less than 10% of those using birth control are using the condom. Rates of condom use are higher in the developed world. In United Kingdom the condom is the second most common method of birth control (22%) while in the United States it is the third most common (15%). About six to nine billion are sold a year.