Blades

A blade is the flat part of a tool, weapon, or machine (such as a fan) that normally has a cutting edge and/or pointed end typically made of a flaking stone, such as flint, or metal, most recently steel. A blade is intentionally used to cut, stab, slice, throw, thrust, position and/or place (an example of this is razor wire), shoot (an example of this is the ballistic knife), scrape (an example of this is an ink eraser) or strike an animate or inanimate object.

The basic idea of a blade is very similar to a sharp point. The shape concentrates all the force onto a very small area, resulting in a high amount of pressure which allows it to penetrate matter. A serrated blade (a blade which has many small "teeth") takes this further as each individual tooth concentrates the force on a smaller area which helps cut through denser materials. A serrated knife can cut through objects solely with a sliding motion with little pushing force, this is useful for tools which require these attributes such as bread knives. Some bladed weapons (and tools) have curved blades. A curve can serve two purposes, the first is that it allows for slicing by continuing to "push" on the surface as it is drawn across it. The other effect is to allow the force to be concentrated in an even smaller area.

Case hardening is a process of increasing the carbon content at the surface of very low carbon steel. It is done by placing the object to be hardened in a sealed container along with carbon-containing material; in antiquity, this material was usually horn or hide. The container would then be heated until it was glowing red, and held at that temperature for a while, based on the size of the part being hardened, allowing carbon to penetrate the steel by a few thousandths of a centimeter. At that point, the object would be dumped out of the container into a water bath to quench it, resulting in a very hard surface, but completely unhardened core. There is very little evidence of this having ever been done to swords except, perhaps, the very earliest of iron blades. Due to the inherent weakness of a sword's cutting edge, coupled with the high-impact stresses of combat, such a thin hardened surface over a soft core would provide very little advantage in terms of edge-holding, other than mild wear resistance.

Blades dull with use and abuse. This is particularly true of acute blades and those made of soft materials. Dulling usually occurs due to contact between the blade and a harder substance such as a ceramic, stone or a tougher metal. To a first approximation, a harder material cannot be deformed by a softer material at their interface because the stress on both materials is the same at the interface and so the softer material will yield first. One exception to this is when the highest stress isn't at the contact point; this is why one can easily bend a steel paper clip even though an end of the same paper clip could scratch one's skin. Swords may have either a straight blade or a curved one. A straight sword was thought to primarily intended for hacking and stabbing, yet recent studies have shown this to be untrue, as many slicing techniques were used.

Banana

Banana is the common name for a type of fruit and also the herbaceous plants of the genus Musa which produce this commonly eaten fruit. They are native to the tropical region of Southeast Asia. Bananas are likely to have been first domesticated in Papua New Guinea. Today, they are cultivated throughout the tropics. The banana fruit grow in hanging clusters, with up to 20 fruit to a tier, and 3–20 tiers to a bunch. The total of the hanging clusters is known as a bunch, or commercially as a "banana stem", and can weigh from 30–50 kg. The fruit averages 125 g, of which approximately 75% is water and 25% dry matter content. Each individual fruit (known as a banana or 'finger') has a protective outer layer (a peel or skin) with a fleshy edible inner portion. Both skin and inner part can be eaten raw or cooked. Western cultures generally eat the inside raw and throw away the skin while some Asian cultures generally eat both the skin and inside cooked. Typically, the fruit has numerous strings which run between the skin and inner part. Bananas are a valuable source of vitamin B₆, vitamin C, and potassium.

The banana plant is a pseudostem that grows to 6 to 7.6 metres (20–25 feet) tall, growing from a corm. Leaves are spirally arranged and may grow 2.7 metres (9 ft) long and 60 cm (2 ft) wide. The banana plant is the largest of all herbaceous flowering plants. The large leaves grow whole, but are easily torn by the wind, resulting in the familiar frond look. Most production for local sale is of green cooking bananas and plantains, as ripe dessert bananas are easily damaged while being transported to market. Even when transported only within their country of origin, ripe bananas suffer a high rate of damage and loss.

Banana chips are a snack produced from dehydrated or fried banana or plantain slices, which have a dark brown color and an intense banana taste. Bananas have also been used in the making of jam. Unlike other fruits, it is difficult to extract juice from bananas because when compressed a banana simply turns to pulp. Seeded bananas, the forerunner of the common domesticated banana, are sold in markets in Indonesia. In India, juice is extracted from the corm and used as a home remedy for the treatment of jaundice, sometimes with the addition of honey.

Bananas are among the most widely consumed foods in the world. Most banana farmers receive a low unit price for their produce as supermarkets buy enormous quantities and receive a discount for that business. Competition amongst supermarkets has led to reduced margins in recent years which in turn has led to lower prices for growers. Chiquita, Del Monte, Dole, and Fyffes grow their own bananas in Ecuador, Colombia, Costa Rica, Guatemala, and Honduras. Banana plantations are capital intensive and demand high expertise, so the majority of independent growers are large and wealthy landowners of these countries. This has led to bananas being available as a "fair trade" or Rainforest Alliance certified item in some countries.

Coconut

The Coconut Palm (Cocos nucifera) is a member of the Family Arecaceae (palm family). It is the only species in the genus Cocos, and is a large palm, growing to 30 m tall, with pinnate leaves 4-6 m long, pinnae 60-90 cm long; old leaves break away cleanly leaving the trunk smooth. The term coconut refers to the seed of the coconut palm. An alternate spelling is cocoanut. The coconut palm is grown throughout the tropical world, for decoration as well as for its many culinary and non-culinary uses; virtually every part of the coconut palm has some human uses.

The coconut has spread across much of the tropics, probably aided in many cases by seafaring people. The fruit is light and buoyant and presumably spread significant distances by marine currents. Fruits collected from the sea as far north as Norway have been found to be viable (and subsequently germinated under the right conditions). In the Hawaiian Islands, the coconut is regarded as a Polynesian introduction, first brought to the islands by early Polynesian voyagers from their homelands in the South Pacific.

The coconut palm thrives on sandy soils and is highly tolerant of salinity. It prefers areas with abundant sunlight and regular rainfall (150 cm to 250 cm annually), which makes colonizing shorelines of the tropics relatively straightforward. Coconuts also need high humidity (70-80%+) for optimum growth, which is why they are rarely seen in areas with low humidity, like the Mediterranean, even where temperatures are high enough. Coconut trees are very hard to establish in dry climates and cannot grow there without frequent irrigation; in drought conditions, the new leaves do not open well, and older leaves may become desiccated; fruit also tends to be shed. Plant densities in Vanuatu for copra production are generally 9 meter, allowing a tree density of 100–160 trees per hectare.

The main coconut producing area in the Middle East is the Dhofar region of Oman. Particular the area around Salalah maintains large coconut plantations similar to those found across the Arabian Sea.The large coconut grooves of Dhofar are already mentioned by the medieval Moroccan traveller Ibn Battuta in his writings known as Al Rihla.This is possible due to an annual rainy season known locally as Khareef.Coconut are also increasingly grown for decorative purposes along the coasts of UAE and Saudi Arabia with the help of irrigation. The UAE has however imposed strict laws on mature coconut tree imports from other countries to reduce the spreading of pests that can spread to other native palm trees such as the date palm.

Watermelon

Watermelon refers to both fruit and plant of a vine-like (climber and trailer) herb originally from southern Africa and one of the most common types of melon. This flowering plant produces a special type of fruit known by botanists as a pepo, which has a thick rind (exocarp) and fleshy center (mesocarp and endocarp); pepos are derived from an inferior ovary and are characteristic of the Cucurbitaceae. The watermelon fruit, loosely considered a type of melon (although not in the genus Cucumis), has a smooth exterior rind (green and yellow) and a juicy, sweet, usually red, but sometimes orange, yellow, or pink interior flesh.

For commercial plantings, one beehive per acre (over 9,000 m² per hive) is the minimum recommendation by the US Department of Agriculture for pollination of conventional, seeded varieties. Because seedless hybrids have sterile pollen, pollinizer rows of varieties with viable pollen must also be planted. Since the supply of viable pollen is reduced and pollination is much more critical in producing the seedless variety, the recommended number of hives per acre, or pollinator density, increases to three hives per acre (1,300 m² per hive).

Although so-called "seedless" watermelons have far fewer seeds than the seeded varieties, they generally contain at least a few soft, pale seeds. They are the product of crossing a female tetraploid plant (itself the product of genetic manipulation, using colchicine) with diploid pollen. The resulting triploid plant is sterile, but will produce the seedless fruit if pollenized by a diploid plant. For this reason, commercially available seedless watermelon seeds actually contain two varieties of seeds; that of the triploid seedless plant itself (recognizable because the seed is larger), and the diploid plant which is needed to pollenize the triploid. Unless both plant types are grown in the same vicinity, no seedless fruit will result.

Fresh watermelon may be eaten in a variety of ways and is also often used to flavor summer drinks and smoothies. Watermelon contains about six percent sugar by weight, the rest being mostly water. As with many other fruits, it is a source of vitamin C. It is not a significant source of other vitamins and minerals unless one eats several kilograms per day. Watermelon seeds are rich in fat and protein, and are widely eaten as a snack, added to other dishes, or used as an oilseed. Specialized varieties are grown which have little watery flesh but concentrate their energy into seed production. In China watermelon seeds are one of the most common snack foods, competing with sunflower seeds, and sold roasted and seasoned. In West Africa, they are pressed for oil, and are popular in egusi soup and other dishes. There can be some confusion between seed-specialized watermelon varieties and the colocynth, a closely-related species with which they share many characteristics, uses, and similar or identical names.

Camphor

Camphor is a waxy, white or transparent solid with a strong, aromatic odor. It is a terpenoid with the chemical formula C₁₀H₁₆O. It is found in wood of the camphor laurel (Cinnamomum camphora), a large evergreen tree found in Asia (particularly in Borneo and Taiwan, hence its alternate name). It also occurs in some other related trees in the laurel family, notably Ocotea usambarensis. It can also be synthetically produced from oil of turpentine. It is used for its scent, as an ingredient in cooking (mainly in India), as an embalming fluid, in religious ceremonies and for medicinal purposes. A major source of camphor in Asia is camphor basil.

Methylation with methyl iodide and a complicated reduction procedure produced camphoric acid. William Perkin published another synthesis a short time later. Previously, some organic compounds (such as urea) had been synthesized in the laboratory as a proof of concept, but camphor was a scarce natural product with a worldwide demand. Komppa realized this and began industrial production of camphor in Tainionkoski, Finland, in 1907.

Modern uses include as a plasticizer for nitrocellulose, as a moth repellent, as an antimicrobial substance, in embalming, and in fireworks. Solid camphor releases fumes that form a rust-preventative coating and is therefore stored in tool chests to protect tools against rust. Camphor crystals are also used to prevent damage to insect collections by other small insects. It is also used in medicine. Camphor is readily absorbed through the skin and produces a feeling of cooling similar to that of menthol and acts as slight local anesthetic and antimicrobial substance. There are anti-itch gel and cooling gels with camphor as the active ingredient. Camphor is an active ingredient (along with menthol) in vapor-steam products, such as Vicks VapoRub, and it is effective as a cough suppressant. It may also be administered orally in small quantities (50 mg) for minor heart symptoms and fatigue.

Camphor is widely used in Hindu religious ceremonies. Hindus worship by lighting a holy flame by burning camphor which forms the most important part of many religious ceremonies. Camphor is used in the Mahashivratri celebrations of Shiva, the Hindu god of destruction and (re)creation. As a natural pitch substance, it burns cool without leaving an ash residue, which symbolizes consciousness. Of late, most temples in southern India have stopped lighting camphor in the main Sanctum Sanctorium due to heavy deposits of carbon; however, open areas do use camphor. It is also found in clarifying masks used for skin. Recently, carbon nanotubes were successfully synthesized using camphor in chemical vapor deposition process

Orange

Oranges originated in Southeast Asia. The fruit of Citrus sinensis is called sweet orange to distinguish it from Citrus aurantium, the bitter orange. In a number of languages, it is known as a "Chinese apple". The name is thought to ultimately derive from the Dravidian and Telugu word for the orange tree, with its final form developing after passing through numerous intermediate languages.

All citrus trees are of the single genus, Citrus, and remain largely interbreedable; that is, there is only one "superspecies" which includes grapefruits, lemons, limes and oranges. Nevertheless, names have been given to the various members of the genus, oranges often being referred to as Citrus sinensis and Citrus aurantium. Fruits of all members of the genus Citrus are considered berries because they have many seeds, are fleshy and soft, and derive from a single ovary. An orange seed is called a pip. The white thread-like material attached to the inside of the peel is called pith.

The Persian orange, grown widely in southern Europe after its introduction to Italy in the 11th century, was bitter. Sweet oranges brought to Europe in the 15th century from India by Portuguese traders, quickly displaced the bitter, and are now the most common variety of orange cultivated. The sweet orange will grow to different sizes and colours according to local conditions, most commonly with ten carpels, or segments, inside. The Valencia or Murcia orange is one of the sweet oranges used for juice extraction. It is a late-season fruit, and therefore a popular variety when the navel oranges are out of season. For this reason, the orange was chosen to be the official mascot of the 1982 FIFA World Cup, which was held in Spain. The mascot was called "Naranjito" ("little orange"), and wore the colours of the Spanish soccer team uniform.

Oranges grown for commercial production are generally grown in groves and are produced throughout the world. The top three orange-producing countries are Brazil, the United States, and Mexico. Oranges are sensitive to frost, and a common treatment to prevent frost damage when sub-freezing temperatures are expected, is to spray the trees with water, since as long as unfrozen water is turning to ice on the trees' branches, the ice that has formed stays just at the freezing point, giving protection even if air temperatures have dropped far lower.

Apple

The apple is the pomaceous fruit of the apple tree, species Malus domestica in the rose family Rosaceae. It is one of the most widely cultivated tree fruits. The tree is small and deciduous, reaching 3 to 12 metres (9.8 to 39 ft) tall, with a broad, often densely twiggy crown. The tree originated from Central Asia, where its wild ancestor is still found today. There are more than 7,500 known cultivars of apples resulting in range of desired characteristics. Cultivars vary in their yield and the ultimate size of the tree, even when grown on the same rootstock.

The center of diversity of the genus Malus is the eastern Turkey. The apple tree was perhaps the earliest tree to be cultivated, and its fruits have been improved through selection over thousands of years. Alexander the Great is credited with finding dwarfed apples in Asia Minor in 300 BCE; those he brought back to Macedonia might have been the progenitors of dwarfing rootstocks. Winter apples, picked in late autumn and stored just above freezing, have been an important food in Asia and Europe for millennia, as well as in Argentina and in the United States since the arrival of Europeans. Apples were brought to North America with colonists in the 1600s, and the first apple orchard on the North American continent was said to be near Boston in 1625. In the 1900s, irrigation projects in Washington state began and allowed the development of the multi-billion dollar fruit industry, of which the apple is the leading species.

Apples appear in many religious traditions, often as a mystical or forbidden fruit. One of the problems identifying apples in religion, mythology and folktales is that the word "apple" was used as a generic term for all (foreign) fruit, other than berries but including nuts, as late as the 17th century. For instance, in Greek mythology, the Greek hero Heracles, as a part of his Twelve Labours, was required to travel to the Garden of the Hesperides and pick the golden apples off the Tree of Life growing at its center.

Apples are self-incompatible; they must cross-pollinate to develop fruit. During the flowering each season, apple growers usually provide pollinators to carry the pollen. Honeybee hives are most commonly used. Orchard mason bees are also used as supplemental pollinators in commercial orchards. Bumble bee queens are sometimes present in orchards, but not usually in enough quantity to be significant pollinators.