Contact lens

A contact lens (also known as a "contact") is a corrective, cosmetic, or sometimes protective lens located on the cornea of the eye.
Contact lenses are obtainable in a number of varieties, including hard and soft. Hard contacts are classically not disposable, while soft contacts often are. Some soft contacts are also well-known as extended wear lenses. Contact lenses (both soft and hard) are made a variety of types of polymers, the latest containing some variant of silicone hydrogel. Previously, hard contact lenses were made of a polymer known as PMMA. They have since been replaced by rigid gas-permeable (RGP) contact lenses. Many contact lenses are made of hydrophilic (water-absorbing) materials, thereby allowing oxygen to reach the cornea, and make the lens more comfortable to wear.
Heavily tinted contacts are tinted to change the color of the iris, and are used for cosmetic reasons. Some standard contact lenses are somewhat tinted in order to make them more visible for handling purposes.

Battlecruisers

Battlecruisers were big warships of the first half of the 20th century. They evolved from armored cruisers and in terms of ship classification they occupy a grey area between cruisers and battleships. Different nations built to commonly different designs. Some battlecruisers were lesser than heavy cruisers while others were larger than contemporaneous battleships. The chief similarity was the role specification. They were supposed to hunt down and outgun smaller warships, and outrun larger warships that they could not outgun. initially, to achieve this, they deviated from the standard practice of providing a ship with enough armour to protect against its own guns. The weight saving from the reduced armour permitted more powerful engines to be fitted. This idea was mostly conceived by British Admiral Jackie Fisher who believed "speed is the best protection". However, as technology developed design philosophy changed and led to the creation of more heavily armoured ships with less powerful guns. They were given different labels, but fundamentally performed the same task

Helicopter

A helicopter is an aircraft which is lifted and propelled by one or more horizontal rotors (propellers). Helicopters are classified as rotary-wing aircraft to differentiate them from conventional fixed-wing aircraft. The word helicopter is resulting from the Greek words helix (spiral) and pteron (wing). The engine-driven helicopter was invented by the Slovak inventor Jan Bahyl. The first stable, fully-controllable helicopter located in production was invented by Igor Sikorsky.
Compared to conventional fixed-wing aircraft, helicopters are much more complex, more expensive to buy and operate, comparatively slow, have shorter range and restricted payload. The compensating advantage is maneuverability: helicopters can hover in place, reverse, and above all take off and land vertically. Subject only to refuelling facilities and load/altitude limitations, a helicopter can travel to any location, and land wherever with a clearing a rotor disk and a half in diameter

Baking powder

Baking Powder is a dry chemical leavening agent used in baking and deodorizing. There are some formulations; all contain an alkali, characteristically sodium bicarbonate (baking soda), and an acid in the form of salt crystals, together by means of starch to keep it dry. When dissolved in water the acid and alkali react and emit carbon dioxide gas, which expands existing bubbles to leaven the mixture. Most current baking powders are double acting, that is, they have two acid salts, one which reacts at room temperature, producing a rise as soon as the dough or batter is ready, and another which reacts at a higher temperature, causing a additional rise during baking. Baking powders that have only the low-temperature acid salts are called single acting. Many recipes call for a process called creaming, where butter and sugar are beaten together to initiate tiny seed bubbles which the leavening gas will more expand.

Common low-temperature acid salts comprise cream of tartar, calcium phosphate, and citrate. High-temperature acid salts are regularly aluminium salts, such as calcium aluminum phosphate. They can be establish not only in many baking powders, but also in many non-dairy coffee creamers. Excess aluminium in the diet may be detrimental to human health, and so baking powders are available without it for people who are concerned and those sensitive to the taste.

While a variety of baking powders were sold in the first half of the 19th century, our modern variants were exposed by Alfred Bird. Eben Norton Horsford, a student of Justus von Liebig, who began his studies on baking powder in 1856, ultimately developed a variety he named in honor of Count Rumford. August Oetker, a German pharmacist, made baking powder very popular when he began selling his mixture to housewives. The same recipe he produced in 1891 is still sold as Backin in Germany. Oetker started the mass production of baking powder in 1898 and patented his technique in 1903.

Assam tea

Assam is a black tea named after the region of its manufacturing:(Assam, India). This tea grown-up at sea level is known for its body, briskness, malty flavor, and strong, bright color. Assam teas, or blends containing Assam, are often sold as "breakfast" teas. English Breakfast tea, Irish Breakfast tea, and Scottish Breakfast Tea are ordinary trade names.
Though "Assam" in general denotes the distinctive black teas from Assam, the region produces relatively smaller quantities of green and white teas as well with their own distinctive characteristics.
Historically, Assam is the second commercial tea making region after China. China and Assam are the only two regions in the world by means of native tea plants. Assam tea revolutionized tea drinking habits in the 19th century since the tea, produced from a different range of the tea plant, yielded a different kind of tea.

Honey formation

Honey is laid by bees as a food source. In cold weather or when food sources are scarce, bees use their stored honey as their source of energy. By contriving for the bee group to make its home in a hive, people have been able to semi-domesticate the insects. In the hive there are three types of bee: the single queen bee, a seasonally variable number of drone bees to fertilize new queens and some 20,000 to 40,000 worker bees. The worker bees raise larvae and collect the nectar that will happen to honey in the hive. They go out, collect the sugar-rich flower nectar and return to the hive. As they leave the flower, bees release Nasonov pheromones. These enable other bees to find their way to the site by smell. Honeybees also release Nasonov pheromones at the entrance to the hive, which enables returning bees to return to the proper hive. In the hive the bees use their "honey stomachs" to ingest and repeat the nectar a number of times until it is partially digested. It is then stored in the honeycomb. Nectar is high in both water content and natural yeasts which, unchecked, would reason the sugars in the nectar to ferment. After the final regurgitation, the honeycomb is left unsealed. Bees inside the hive fan their wings, creating a strong draft across the honeycomb. This enhances evaporation of much of the water from the nectar. The lessening in water content, which raises the sugar concentration, prevents fermentation. Ripe honey, as removed from the hive by the beekeeper, has a long shelf life and will not ferment.
The beekeeper encourages overproduction of honey within the hive so that the excess can be taken without endangering the bees. When sources of foods for the bees are short the beekeeper may have to feed the bees other forms of sugar so they can survive.