refrigerator |
lettuce |
top 10 words in brain distribution (in article): century cut time modern design type metal style allow hold |
top 10 words in brain distribution (in article): species form century plant water food type produce family world |
top 10 words in brain distribution (not in article): wear horse church iron blade head woman steel bishop handle |
top 10 words in brain distribution (not in article): wear horse bird egg woman fish clothe time female saddle |
times more probable under refrigerator 30 20 10 6 4 2.5 1.25 1 1.25 2.5 4 6 10 20 30 times more probable under lettuce (words not in the model) | |
A refrigerator'" (often called a "'fridge'" for short) is a cooling appliance comprising a thermally insulated compartment and a heat pump: a mechanism to transfer heat from it to the external environment, cooling the contents to a temperature below ambient. Refrigerators are extensively used to store foods which deteriorate at ambient temperatures; spoilage from bacterial growth and other processes is much slower at low temperatures. A device described as a "refrigerator" maintains a temperature a few degrees above the freezing point of water; a similar device which maintains a temperature below the freezing point of water is called a "'freezer'". The refrigerator is a relatively modern invention among kitchen appliances. It replaced the icebox, which had been a common household appliance for almost a century and a half prior. For this reason, a refrigerator is sometimes referred to as an "icebox". Freezers keep their contents frozen. They are used both in households and for commercial use. Most freezers operate around minus 18 °C (0 °F). Domestic freezers can be included as a compartment in a refrigerator, sharing the same mechanism or with a separate mechanism, or can be standalone units. Domestic freezers are generally upright units, resembling refrigerators, or chests, resembling upright units laid on their backs. Many modern freezers come with an icemaker. Commercial fridge and freezer units, which go by many other names, were in use for almost 40 years prior to the common home models. They used toxic ammonia gas systems, making them unsafe for home use. Practical household refrigerators were introduced in 1915 and gained wider acceptance in the United States in the 1930s as prices fell and non-toxic, non-flammable synthetic refrigerants such as Freon or R-12 were introduced. It is notable that while 60% of households in the US owned a refrigerator by the 1930s, it was not until 40 years later, in the 1970s, that the refrigerator achieved a similar level of penetration in the United Kingdom. History. Before the invention of the refrigerator, icehouses were used to provide cool storage for most of the year. Placed near freshwater lakes or packed with snow and ice during the winter, they were once very common. Using the environment to cool foodstuffs is still common today. On mountainsides, runoff from melting snow higher up is a convenient way to cool drinks, and during the winter months simply placing milk outside is sufficient to greatly extend its useful life. In the 11th century, the Persian physicist and chemist, Ibn Sina (Avicenna), invented the refrigerated coil, which condenses aromatic vapours. This was a breakthrough in distillation technology and he made use of it in his steam distillation process, which requires refrigerated tubing, to produce essential oils. The first known artificial refrigeration was demonstrated by William Cullen at the University of Glasgow in 1748. Between 1805, when Oliver Evans designed the first refrigeration machine that used vapor instead of liquid, and 1902 when Willis Haviland Carrier demonstrated the first air conditioner, scores of inventors contributed many small advances in cooling machinery. In 1850 or 1851, Dr. John Gorrie demonstrated an ice maker. In 1857, Australian James Harrison introduced vapor-compression refrigeration to the brewing and meat packing industries. Ferdinand Carré of France developed a somewhat more complex system in 1859. Unlike earlier compression-compression machines, which used air as a coolant, Carré's equipment contained rapidly expanding ammonia. The absorption refrigerator was invented by Baltzar von Platen and Carl Munters in 1922, while they were still students at the Royal Institute of Technology in Stockholm, Sweden. It became a worldwide success and was commercialized by Electrolux. Other pioneers included Charles Tellier, David Boyle, and Raoul Pictet. At the start of the 20th Century, about half of households in the United States relied on melting ice (in an icebox) to keep food cold, while the remaining half had no cooled storage at all. The ice used for household storage was expensive because ice had to be cut from winter ponds (or mechanically produced), stored centrally until needed, and delivered regularly. In a few exceptional cases, mechanical refrigeration systems had been adapted by the start of the 20th century for use in the homes of the very wealthy, and might be used for cooling both living and food storage areas. One early system was | Lettuce'" ("Lactuca sativa") is a temperate annual or biennial plant of the daisy family Asteraceae. It is most often grown as a leaf vegetable. In many countries, it is typically eaten cold, raw, in salads, hamburgers, tacos, and in many other dishes. In some places, including China, lettuce is typically eaten cooked and use of the stem is as important as use of the leaf. Both the English name and the Latin name of the genus are ultimately derived from "lac", the Latin word for “milk”, referring to the plant’s milky juice. Mild in flavour, it has been described over the centuries as a cooling counterbalance to other ingredients in a salad. In his humorous essay "100 Things I chew", filmmaker John Waters refers to iceberg lettuce as "the polyester of greens". Description. The lettuce plant has a short stem initially (a rosette growth habit), but when it blooms, the stem lengthens, branches, and produces many flower heads that look like those of dandelions, but smaller. This is referred to as bolting. When grown to eat, lettuce is harvested before it bolts. Lettuce is used as a food plant by the larvae of some Lepidoptera. The largest lettuce head, of the Salad Bowl cultivar, weighed 11 kg (25 lb) grown by Colin Bowcock of Willaston, England, in 1974. Cultivation. Lettuce is grown commercially worldwide, hardy to Zone 6, requiring light, sandy, humus rich, moist soil. It dislikes dry conditions and can cause plants to bolt (go to seed). Early and late sowing in sunny positions or summer crops in shade. It is considered fairly easy to grow and a suitable crop for beginners. "Planting Depth:" Some resources suggest planting seeds by covering lightly with soil while others suggest a depth of 1 4 to 1 2 inch "Planting Spacing:" Thin seedlings to 10 cm (4 in) apart for leaf lettuce [1 sq. m (9 sq ft)] and 6 to 8 inches apart for Cos or Butterhead (4 sq ft 1 sq ft), transplant Crisphead seedlings 10 to 12 inches apart in the row (1 sq ft). "Row Spacing:" 12 18 inches apart History. The earliest depiction of lettuce is in the carvings at the temple of Senusret I at Karnak, where he offers milk to the god Min, to whom the lettuces was sacred. Lettuce was considered an aphrodisiac food in Ancient Egypt, and appears as such in "The Contendings of Horus and Seth". Later, Ancient Greek physicians believed lettuce could act as a sleep-inducing agent. The Romans cultivated it, and it eventually made its way to France cultivated of the Papal Court at Avignon. Christopher Columbus introduced lettuce to the new world. Cultivars. There are six commonly recognised Cultivar Groups of lettuce which are ordered here by head formation and leaf structure; there are hundreds of cultivars of lettuce selected for leaf shape and colour, as well as extended field and shelf life, within each of these Cultivar Groups: Some lettuces (especially iceberg) have been specifically bred to remove the bitterness from their leaves. These lettuces have a high water content with very little nutrient value. The more bitter lettuces and the ones with pigmented leaves contain antioxidants. Breeding. "L. sativa" can easily be bred with closely related species in "Lactuca" such as "L. serriola", "L. saligna", and "L. virosa", and breeding programs for cultivated lettuce have included those species to broaden the available gene pool. Starting in the 1990s, such programs began to include more distantly related species such as "L. tatarica". Seed Saving. Inbreeding plant, flowers form in heads of 10-25 individual florets of perfect flowers. Considered suitable for seed-saving beginners Production. The Food and Agriculture Organization of the United Nations reports that world production of lettuce and chicory for calendar year 2007 was 23.55 million tons, primarily coming from China(51%), United States(22%) and Spain(5%). Nutrition. Lettuce is a fat free, low calorie food. It is a valuable source of vitamin A and folic acid. Lactucarium (or “Lettuce Opium”) is a mild opiate-like substance that is contained in all types of lettuce. Both the Romans and Egyptians took advantage of this property eating lettuce at the end of a meal to induce sleep. Religious restrictions. The Yazidi of northern Iraq consider eating lettuce taboo. |