1.
Deerskin (novel)
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Deerskin is a dark fantasy novel by Robin McKinley, first published in 1993. It is based on an old French fairy tale by Charles Perrault called Peau dâne and it was nominated for the Mythopoeic Fantasy Award for Adult Literature. The book contains numerous adult themes including incest, rape, and it features McKinleys typical protagonist, the resourceful heroine overcoming psychological trauma, and her favored motif of the animal helper. Although Lissar is the daughter of the most beautiful queen and most handsome king in all the land, she is a child whose only true companion is her dog. She was mostly ignored during her childhood due to the fact that her parents were the two most splendid people in all the seven kingdoms, lissars mother falls ill and starts to lose her beauty. This causes her to lose her will to live, because she wants to be remembered as the most beautiful person and she sends for artists from all the kingdoms, and eventually one is chosen to paint a portrait of her as she was before her illness. He works nonstop, as if driven, for a fortnight until the painting is completed and shown to the queen. After looking at the painting, she forces the king to swear that he will only remarry if he can find a more beautiful than she. This seemingly impossible condition is not, however, insurmountable, as Lissar matures, she not only the very image of her mother. The king becomes obsessed with his daughter, and insists that he wants to marry her, Lissar refuses him and locks herself in a room. Eventually the king finds a way into the room, rapes Lissar, Lissar and Ash escape from the king and find their way to a cabin in the mountains. Lissar, impregnated by her father the king, miscarries and nearly dies, as another gift the goddess gives Lissar time to heal and to forget what happened to her. Lissar travels to a different kingdom and offers to work for the king, the prince, Ossin, assigns her to raise a litter of puppies whose mother had died. The goddesss alterations, however, were more than physical, Lissar, now identified as Deerskin, discovers that she has supernatural powers, including the ability to find lost children and objects. She falls in love with Ossin and he with her, but, still burdened by her past, she flees when Ossin proposes to her at a ball and returns to the cabin in the mountains with Ash and the puppies. After spending the winter recovering, Deerskin feels compelled to return to Ossins city, as she nears the city, she hears about a wedding and assumes that it is Ossins. She realizes to her horror that the king, her father, is going to marry Ossins younger sister, Deerskin reveals her true identity as the bridegrooms daughter and calls her father to account for his actions, using the goddesss powers to punish him for his crimes. Confronting her father finally frees Lissar to accept Ossins love, the story ends with Lissar tentatively coming back to Ossin, offering to give their relationship a chance
2.
Tanning (leather)
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Tanning is the process of treating skins and hides of animals to produce leather. A tannery is the place where the skins are processed, Tanning hide into leather involves a process which permanently alters the protein structure of skin, making it more durable and less susceptible to decomposition, and also possibly coloring it. Before tanning, the skins are unhaired, degreased, desalted and soaked in water over a period of 6 hours to 2 days, historically this process was considered a noxious or odoriferous trade and relegated to the outskirts of town. Traditionally, tanning used tannin, a chemical compound from which the tanning process draws its name. The use of a solution was adopted by tanners in the Industrial Revolution. The English word for tanning is from medieval Latin tannāre, deriv. of tannum and this refers to use of the bark of oaks in some kinds of hide preservation. Ancient civilizations used leather for waterskins, bags, harnesses and tack, boats, armour, quivers, scabbards, boots, Tanning was being carried out by the inhabitants of Mehrgarh in India between 7000 and 3300 BC. Around 2500 BC, the Sumerians began using leather, affixed by copper studs, formerly, tanning was considered a noxious or odoriferous trade and relegated to the outskirts of town, amongst the poor. Indeed, tanning by ancient methods is so foul smelling, tanneries are still isolated from those towns today where the old methods are used, Skins typically arrived at the tannery dried stiff and dirty with soil and gore. First, the ancient tanners would soak the skins in water to clean, then they would pound and scour the skin to remove any remaining flesh and fat. Next, the tanner needed to remove the hair from the skin and this was done by either soaking the skin in urine, painting it with an alkaline lime mixture, or simply allowing the skin to putrefy for several months then dipping it in a salt solution. After the hairs were loosened, the tanners scraped them off with a knife, once the hair was removed, the tanners would bate the material by pounding dung into the skin, or soaking the skin in a solution of animal brains. Bating was a process which relied on enzymes produced by bacteria found in the dung. Among the kinds of dung commonly used were those of dogs or pigeons, sometimes, the dung was mixed with water in a large vat, and the prepared skins were kneaded in the dung water until they became supple from bacterial enzyme action, but not too soft. The ancient tanner might use his feet to knead the skins in the dung water. This combination of urine, animal feces, and decaying flesh made ancient tanneries malodorous, children employed as dung gatherers were a common sight in ancient cities. Also common were piss-pots located on street corners, where human urine could be collected for use in tanneries or by washerwomen, historically the actual tanning process used vegetable tanning. In some variations of the process, cedar oil, alum, as the skin was stretched, it would lose moisture and absorb the agent
3.
Rawhide (textile)
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Rawhide is a hide or animal skin that has not been exposed to tanning. It is similar to parchment, much lighter in color than leather made by traditional vegetable tanning, the skin from buffalo, deer, elk or cattle from which most rawhide originates is prepared by removing all fur, meat and fat. The hide is then stretched over a frame before being dried. The resulting material is hard and translucent and it can be shaped by rewetting and forming before being allowed to thoroughly re-dry. It can be rendered more pliable by working, i. e. bending repeatedly in multiple directions, often by rubbing it over a post and it may also be oiled or greased for a degree of waterproofing. It is often used for such as whips, drumheads or lampshades. It is thought to be more durable than leather, especially in items suffering abrasion during use and it can also be used as a backing on a wooden bow. Such a backing prevents the bow from breaking by taking a share of the tension stress, bows made from weaker woods such as birch or cherry benefit more from a rawhide backing. Rawhide is more susceptible to water than leather, and it quickly softens, rawhide laces often sold for boots or baseball gloves are made of normal tanned leather rather than actual rawhide. Rawhide is not pliable when dry and would be unsuitable for that use, traditional gauchos boots are made with horse feet rawhide. Gauchos skin the animal and put the freshly skinned hides on their feet like socks, like ancient Roman cothurnus, the rudimentary boots have no toe box and do not cover the toes completely. As a chew toy for dogs, it is effective when used for training dogs. Wet rawhide has been used by earlier cultures as a means of torture or execution
4.
Putting-out system
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The putting-out system is a means of subcontracting work. Historically, it was known as the workshop system and the domestic system. In putting-out, work is contracted by an agent to subcontractors who complete the work in off-site facilities. Early factory owners sometimes had to build dormitories to house workers, especially girls, putting-out workers had some flexibility to balance farm and household chores with the putting-out work, this being especially important in winter. The development of this trend is considered to be a form of proto-industrialization. At that point, it underwent name and geographical changes, however, bar some technological advancements, the putting-out system has not changed in essential practice. Contemporary examples can be found in China, India, and South America, in small arms making as in lock production, the workshop system rather than the factory system was the rule. All of the processes were carried out under different cottage roofs and it was replaced by inside contracting and the factory system. The domestic system was a system of cloth production in Europe. It was also used in other industries, including the manufacture of wrought iron ironware such as pins, pots. It existed as early as the 15th century, but was most prominent in the 17th and 18th centuries and it served as a way for capitalists and workers to bypass the guild system, which was thought to be cumbersome and inflexible. Workers would work from home, manufacturing individual articles from raw materials, then bring them to a place of business, such as a marketplace or a larger town, to be assembled. The raw materials were provided by the merchant, who received the finished product. As the woman of a family usually worked at home, someone was there to look after any children. These considerable sums of money led to a much wealthier peasantry with more furniture, higher-quality food. It was mostly centralized in Western Europe and did not take a hold in Eastern Europe. Of course, the acquisition of profit largely depended on which part of the system one was associated with. If one was a worker in the London textiles industry, for example, likewise, the fourteen-hour days led to many untimely deaths
5.
Heavy industry
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Heavy industry is industry that involves one or more characteristics such as large and heavy products, large and heavy equipment and facilities, or complex of numerous processes. Because of those factors, heavy industry involves higher capital intensity than light industry does, traditional examples from the mid-19th century through the early 20th included steelmaking, artillery production, locomotive erection, machine tool building, and the heavier types of mining. Modern shipbuilding is considered heavy industry, many East Asian countries rely on heavy industry as part of their overall economies. Heavy industry is sometimes a special designation in local zoning laws. Morris Teubal, Heavy and Light Industry in Economic Development The American Economic Review, Vol.63, some Definitions in the Vocabulary of Geography, IV, British Association Glossary Committee, The Geographical Journal, Vol.118, No.3. Definition of Heavy Industry according to Investopedia. com
6.
Bookbinding
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Bookbinding is the process of physically assembling a book from an ordered stack of paper sheets that are folded together into sections or sometimes left as a stack of individual sheets. The stack is then bound together along one edge by either sewing with thread through the folds or by a layer of flexible adhesive, for protection, the bound stack is either wrapped in a flexible cover or attached to stiff boards. Finally, a cover is adhered to the boards and a label with identifying information is attached to the covers along with additional decoration. Bookbinding is a trade that relies on basic operations of measuring, cutting. A finished book depends on a minimum of two dozen operations to complete but sometimes more than double that according to the specific style. All operations have an order and each one relies on accurate completion of the previous step with little room for back tracking. An extremely durable binding can be achieved by using the best hand techniques, Bookbinding combines skills from other trades such as paper and fabric crafts, leather work, model making, and graphic arts. It requires knowledge about numerous varieties of book structures along with all the internal and external details of assembly, a working knowledge of the materials involved is required. Bookbinding is a craft of great antiquity, and at the same time. The division between craft and industry is not so wide as might at first be imagined and it is interesting to observe that the main problems faced by the mass-production bookbinder are the same as those that confronted the medieval craftsman or the modern hand binder. Before the computer age, the bookbinding trade involved two divisions, second was Letterpress binding which deals with making new books intended to be read from and includes fine binding, library binding, edition binding, and publishers bindings. A result of the new bindings is a third division dealing with the repair, restoration, with the digital age, personal computers have replaced the pen and paper based accounting that used to drive most of the work in the stationery binding industry. There is a grey area between the two divisions. There are cases where the printing and binding jobs are combined in one shop, a step up to the next level of mechanization is determined by economics of scale until you reach production runs of ten thousand copies or more in a factory employing a dozen or more workers. The craft of bookbinding probably originated in India, where religious sutras were copied on to palm leaves with a metal stylus, the leaf was then dried and rubbed with ink, which would form a stain in the wound. The finished leaves were given numbers, and two long twines were threaded through each end through wooden boards, making a palm-leaf book, when the book was closed, the excess twine would be wrapped around the boards to protect the manuscript leaves. Buddhist monks took the idea through Afghanistan to China in the first century BC, similar techniques can also be found in ancient Egypt where priestly texts were compiled on scrolls and books of papyrus. Another version of bookmaking can be seen through the ancient Mayan codex, writers in the Hellenistic-Roman culture wrote longer texts as scrolls, these were stored in boxes or shelving with small cubbyholes, similar to a modern winerack
7.
Saddle seat
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Saddle seat is a style of horseback riding within the category of English riding that is designed to show off the high action of certain horse breeds. The style developed into its form in the United States. To a much lesser extent, it is ridden with American action horse breeds in Europe, the goal of the saddle seat riding style is to show off the horses extravagant gaits, particularly the trot. Saddle seat riding began as a style within the broader group of English riding disciplines developed in the United States from two sources. The first was the Plantation tradition of the American South, where smooth-moving, high-stepping horses were used by owners and overseers to travel across the fields. The horses had to be smooth riding and comfortable enough for hours of riding while overseeing the plantation, hence, the term park horse is still used today to describe competitions where the action of the horse is of paramount importance. Saddle seat is a style of English riding that differs considerably from other such as hunt seat. To the casual observer the rider sits back in the saddle. Riders in equitation classes are penalized for leaning forward to any significant degree, however, like any other riding discipline, the position of the rider reflects the desired position of the horse. The rider must make the riding look effortless, and stay still and well-formed on the horse, sitting upright, with back and posting that is graceful. Horses that naturally have a neck with high head carriage, as well as animated gaits. They should be very energetic but still remain responsive to the riders aids, several breeds do well in this discipline, with the most well-known being the American Saddlebred. Other breeds commonly exhibited in saddle seat style are the National Show Horse, Tennessee Walking Horses, Racking Horses, Spotted Saddle Horses, Morgans, and Arabians. In addition, Hackneys, Dutch Harness Horses, Paso Finos, Missouri Foxtrotters, less often, Friesians and Andalusians are exhibited. Classes under saddle may include, Three-Gaited, Open to American Saddlebreds, shown at the walk, trot, and canter. Five-gaited, Open to American Saddlebreds, shown at the walk, trot, and canter, as well as the four -beat ambling gaits known as the rack, Plantation Walker, Open to Tennessee Walking Horses, shown at the flat walk, running walk, and canter. Park, A class designation used in Saddlebred, Arabian, and Morgan competition, where horses are shown at a walk, trot, and canter, judged on their brilliant, high action. Pleasure, An English pleasure class designation used in almost every breed, designated classes where good manners, most pleasure classes require horses to show at a walk, trot and canter, often calling for extended gaits
8.
East Timor
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East Timor or Timor-Leste, officially the Democratic Republic of Timor-Leste, is a sovereign state in Maritime Southeast Asia. It comprises the half of the island of Timor, the nearby islands of Atauro and Jaco, and Oecusse. The countrys size is about 15,410 km2, nine days later, it was invaded and occupied by Indonesia and was declared Indonesias 27th province the following year. The Indonesian occupation of East Timor was characterised by a highly violent decades-long conflict between separatist groups and the Indonesian military, in 1999, following the United Nations-sponsored act of self-determination, Indonesia relinquished control of the territory. East Timor became the first new state of the 21st century on 20 May 2002 and joined the United Nations. In 2011, East Timor announced its intention to gain status in the Association of Southeast Asian Nations by applying to become its eleventh member. It is one of two predominantly Christian nations in Southeast Asia, the other being the Philippines. In Indonesian, the country is called Timor Timur, thus using the Portuguese name for the island followed by the word for east, the official names under the Constitution are Democratic Republic of Timor-Leste in English, República Democrática de Timor-Leste in Portuguese and Repúblika Demokrátika Timór-Leste in Tetum. Humans first settled in East Timor 42,000 years ago, descendants of at least three waves of migration are believed still to live in East Timor. The first is described by anthropologists as people of the Veddo-Australoid type, around 3000 BC, a second migration brought Melanesians. The earlier Veddo-Australoid peoples withdrew at this time to the mountainous interior, finally, proto-Malays arrived from south China and north Indochina. Hakka traders are among those descended from this final group, Timorese origin myths tell of ancestors that sailed around the eastern end of Timor arriving on land in the south. Some stories recount Timorese ancestors journeying from the Malay Peninsula or the Minangkabau highlands of Sumatra, austronesians migrated to Timor, and are thought to be associated with the development of agriculture on the island. Thirdly, Proto-Malays arrived from south China and north Indochina, before European colonialism, Timor was included in Chinese and Indian trading networks, and in the 14th century was an exporter of aromatic sandalwood, slaves, honey, and wax. It was the abundance of sandalwood in Timor that attracted European explorers to the island in the early 16th century. During that time, European explorers reported that the island had a number of small chiefdoms or princedoms, the Portuguese established outposts in Timor and Maluku. Effective European occupation of a part of the territory began in 1769, when the city of Dili was founded. For the Portuguese, East Timor remained little more than a trading post until the late nineteenth century, with minimal investment in infrastructure, health
9.
Fez, Morocco
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Fez is the second largest city of Morocco, with a population of 1.1 million. Fez was the city of modern Morocco until 1925 and is now the capital of the Fès-Meknès administrative region. The city has two old medina quarters, the larger of which is Fes el Bali and it is listed as a World Heritage Site and is believed to be one of the worlds largest urban pedestrian zones. University of Al Quaraouiyine, founded in 859, is the oldest continuously functioning university in the world, the city has been called the Mecca of the West and the Athens of Africa. The Arabic word فأس Faʾs means pickaxe, which legends say Idris I of Morocco used when he created the lines of the city, one noticeable thing was that the pickaxe was made from silver and gold. During the rule of the Idrisid dynasty, Fez consisted of two cities, Fas Elbali, founded by Idris I, and al-ʿĀliyá, founded by his son and it is not known whether the name al-ʿĀliyá ever referred to both urban areas. It wasnt until 1070 that the two agglomerations were united and the name Fas was used for the combined site, the city was founded on a bank of the Jawhar river by Idris I in 789, founder of the Zaydi Shii Idrisid dynasty. His son, Idris II, built a settlement on the river bank. These settlements would soon develop into two walled and largely autonomous sites, often in conflict with one another, Madinat Fas, in 808 Al-Aliya replaced Walili as the capital of the Idrisids. The Andalusians settled in what is called the Old Fez, while the Tunisians found their home in the New Fez and these two waves of immigrants would subsequently give their name to the sites Adwat Al-Andalus and Adwat al-Qarawiyyin. Upon the death of Idris II in 828, the territory was divided among his sons. The newly fragmented Idrisid power would never again be reunified, during Yahya ibn Muhammads rule in Fez the Kairouyine mosque, one of the oldest and largest in Africa, was built and its associated University of Al Quaraouiyine was founded. Comparatively little is known about Idrisid Fez, owing to the lack of historical narratives. The sources that mention Idrisid Fez, describe a rather rural one, not having the cultural sophistication of the important cities of Al-Andalus and Ifriqiya. In the 10th century the city was contested by the Caliphate of Córdoba and the Fatimid Caliphate of Tunisia, the Fatimids took the city in 927 and expelled the Idrissids, after which their Miknasa were installed there. The Miknasa were driven out of Fez in 980 by the Maghrawa, their fellow Zenata and it was in this period that the great Andalusian ruler Almanzor commissioned the Maghrawa to rebuild and refurnish the Al-Kairouan mosque, giving it much of its current appearance. Thus, the two grew into each other, being now only separated by their walls and the river. His sons fortified the city to a great extent and this could not keep the Almoravid emir Ibn Tashfin from conquering it in 1070, after more than a decade of battling the Zenata warriors in the area and constant besieging of the city
10.
Morocco
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Morocco, officially known as the Kingdom of Morocco, is a sovereign country located in the Maghreb region of North Africa. Geographically, Morocco is characterized by a mountainous interior, large tracts of desert. Morocco has a population of over 33.8 million and an area of 446,550 km2 and its capital is Rabat, and the largest city is Casablanca. Other major cities include Marrakesh, Tangier, Tetouan, Salé, Fes, Agadir, Meknes, Oujda, Kenitra, a historically prominent regional power, Morocco has a history of independence not shared by its neighbours. Marinid and Saadi dynasties continued the struggle against foreign domination, the Alaouite dynasty, the current ruling dynasty, seized power in 1666. In 1912 Morocco was divided into French and Spanish protectorates, with a zone in Tangier. Moroccan culture is a blend of Arab, indigenous Berber, Sub-Saharan African, Morocco claims the non-self-governing territory of Western Sahara as its Southern Provinces. Morocco annexed the territory in 1975, leading to a war with indigenous forces until a cease-fire in 1991. Peace processes have thus far failed to break the political deadlock, Morocco is a constitutional monarchy with an elected parliament. The King of Morocco holds vast executive and legislative powers, especially over the military, foreign policy, the king can issue decrees called dahirs which have the force of law. He can also dissolve the parliament after consulting the Prime Minister, Moroccos predominant religion is Islam, and the official languages are Arabic and Tamazight. The Moroccan dialect, referred to as Darija, and French are also widely spoken, Morocco is a member of the Arab League, the Union for the Mediterranean, and the African Union. It has the fifth largest economy of Africa, the full Arabic name al-Mamlakah al-Maghribiyyah translates to Kingdom of the West, although the West in Arabic is الغرب Al-Gharb. The basis of Moroccos English name is Marrakesh, its capital under the Almoravid dynasty, the origin of the name Marrakesh is disputed, but is most likely from the Berber words amur akush or Land of God. The modern Berber name for Marrakesh is Mṛṛakc, in Turkish, Morocco is known as Fas, a name derived from its ancient capital of Fes. The English name Morocco is an anglicisation of the Spanish Marruecos, the area of present-day Morocco has been inhabited since Paleolithic times, sometime between 190,000 and 90,000 BC. During the Upper Paleolithic, the Maghreb was more fertile than it is today, twenty-two thousand years ago, the Aterian was succeeded by the Iberomaurusian culture, which shared similarities with Iberian cultures. Skeletal similarities have been suggested between the Iberomaurusian Mechta-Afalou burials and European Cro-Magnon remains, the Iberomaurusian was succeeded by the Beaker culture in Morocco
11.
Marrakesh
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Marrakesh, also known by the French spelling Marrakech, is a major city of the Kingdom of Morocco. It is the fourth largest city in the country, after Casablanca, Fes and it is the capital city of the mid-southwestern region of Marrakesh-Safi. Marrakesh is possibly the most important of Moroccos four former imperial cities, the region has been inhabited by Berber farmers since Neolithic times, but the actual city was founded in 1062 by Abu Bakr ibn Umar, chieftain and cousin of Almoravid king Yusuf ibn Tashfin. In the 12th century, the Almoravids built many madrasas and mosques in Marrakesh that bear Andalusian influences. The red walls of the city, built by Ali ibn Yusuf in 1122–1123, Marrakesh grew rapidly and established itself as a cultural, religious, and trading centre for the Maghreb and sub-Saharan Africa, Jemaa el-Fnaa is the busiest square in Africa. After a period of decline, the city was surpassed by Fes, beginning in the 17th century, the city became popular among Sufi pilgrims for Moroccos seven patron saints, who are entombed here. In 2009, Marrakesh mayor Fatima Zahra Mansouri became the woman to be elected mayor in Morocco. Like many Moroccan cities, Marrakesh comprises an old fortified city packed with vendors and their stalls, bordered by modern neighborhoods, today it is one of the busiest cities in Africa and serves as a major economic centre and tourist destination. Tourism is strongly advocated by the reigning Moroccan monarch, Mohammed VI, despite the economic recession, real estate and hotel development in Marrakesh has grown dramatically in the 21st century. Marrakesh is particularly popular with the French, and numerous French celebrities own property in the city, Marrakesh has the largest traditional market in Morocco, with some 18 souks selling wares ranging from traditional Berber carpets to modern consumer electronics. Crafts employ a significant percentage of the population, who sell their products to tourists. Marrakesh is one of North Africa’s largest centres of wildlife trade, much of this trade can be found in the medina and adjacent squares. Tortoises are particularly popular for sale as pets but Barbary macaques and snakes can also be seen, Marrakesh is served by Ménara International Airport and the Marrakesh railway station, which connects the city to Casablanca and northern Morocco. Marrakesh has several universities and schools, including Cadi Ayyad University, a number of Moroccan football clubs are located here, including Najm de Marrakech, KAC Marrakech, Mouloudia de Marrakech and Chez Ali Club de Marrakech. The Marrakesh Street Circuit hosts the World Touring Car Championship, Auto GP, the exact meaning of the name is debated. The probable origin of the name Marrakesh is from the Berber words amur akush, the word mur is used now in Berber mostly in the feminine form tamurt. The common English spelling is Marrakesh, although Marrakech is also widely used, the name is spelled Mṛṛakc in the Berber Latin alphabet, Marraquexe in Portuguese, Marraquech in Spanish, and Mer-reksh in Moroccan Arabic. From medieval times until around the beginning of the 20th century, the name for Morocco is still Marrakesh to this day in Persian and Urdu as well as many other South Asian languages
12.
Leather production processes
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The leather manufacturing process is divided into three sub-processes, preparatory stages, tanning and crusting. All true leathers undergo these sub-processes. A further sub-process, surface coating may be added into the sequence, the list of operations that leathers undergo vary with the type of leather. The leather making process is in general restricted to batch processing, the operation flow has to follow the preparatory → tanning → crusting → surface coating sub-process order without deviation, but some of the sub-processes can be omitted to make certain leathers. The preparatory stages are when the hide/skin is prepared for tanning, during the preparatory stages many of the unwanted raw skin components are removed. Many options for pretreatment of the skin exist, not all of the options may be performed. Preparatory stages may include, preservation- the hide/skin is treated with a method which renders it temporarily imputrescible, soaking - water for purposes of washing or rehydration is reintroduced. Liming - unwanted proteins and opening up is achieved, unhairing - the majority of hair is removed. Fleshing - subcutaneous material is removed, splitting - the hide/skin is cut into two or more horizontal layers. Reliming - the hide/skin is further treated to achieve more opening up or more protein removal, frizing - physical removal of the fat layer inside the skin. Bleaching - chemical modification of dark pigments to yield a lighter coloured pelt. pickling - lowering of the pH value to the acidic region, must be done in the presence of salts. Pickling is normally done to help with the penetration of certain tanning agents, a large number of different tanning methods and materials can be used, the choice is ultimately dependent on the end application of the leather. The most commonly used tanning material is chromium, which leaves the leather, once tanned, a blue colour. The acidity of hides once they have finished pickling will typically be between pH of 2. 8-3.2, at this point the hides are loaded in a drum and immersed in a float containing the tanning liquor. The hides are allowed to soak and the tanning liquor slowly penetrates through the substance of the hide. Regular checks will be made to see the penetration by cutting the cross section of a hide, once an even degree of penetration is observed, the pH of the float is slowly raised in a process called basification. The pH of the leather when chrome tanned would typically finish somewhere between 3. 8-4.2, crusting is when the hide/skin is thinned, retanned and lubricated. Often a coloring operation is included in the crusting sub-process, the chemicals added during crusting have to be fixed in place
13.
Liming (leather processing)
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Liming is a process used for parchment or leather processing, in which hides are soaked in an alkali solution. It is performed using a drum and paddle or a pit and its objectives are, Removal of interfibrillary proteins. Collagen swelling due to the alkaline pH, Removal of natural grease and fats Liming operations of cattle hides usually last 18 hours and are generally associated with the alkaline phase of beamhouse operations. The interfibrillary proteins are denatured by the presence of alkali, rendered soluble, Removal is done by the mechanical action of liming or reliming, but more prominently when the pelt is deswelled. Failure to remove these proteins results in a hard, tinny leather that is brittle and inflexible, keratin that is present in the hair, scales and in the epidermis of the skin is hydrolyzed in the presence of alkali. The disulfide bridges found in protein are cleaved but can be reformed. Long periods of liming will result in hair removal, the main removal of keratin is performed using the unhairing operation. In traditional processing liming/unhairing was indivisible and took place at the same time, modern liming methods, and in particular, the processing of sheepskins the hair is removed first and then limed in a liming drum. In hair-save technology, the hides are unhaired first and then limed for a further 12–18 hours, the presence of calcium hydroxide results in the alkaline swelling of skin. The result is the influx of water into the hide/skin and an increase in fibre diameter. The thickness of the skin increases, but the area of the pelt decreases. The weight increase, due to the uptake of water results in a doubling of the hide/skin weight, but this weight also needs to take into consideration that proteins have been removed and the fleshing operation is often performed after liming. The action of liming, in particular the swelling of the skin, due to the fibre diameter increasing, the bundle sheath cannot contain the thicker fibres and it bursts open. This allows increased access to the fibres which allows better tanning, retanning, dyeing and fatliquoring
14.
Deliming
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The deliming operation in leather processing is a drum/paddle or pit based operation where two main objectives are met, Removal of alkali from the pelt and the consequent deswelling of the fibres. Lowering of the liquor pH to the used in the bating process. Deliming operations of cattle hides usually last 2 hours and are associated with the alkaline phase of beamhouse operations. The progress of deliming in pelts is monitored by the checking of pH values of process liquors, phenolphthalein is used to monitor deliming pelt cross-sectional progress. As an acid is added it lowers the pH value of the internal pelt solution, the lowering of the pH results in rapid protonation of the collagen basic groups. The acid present in the deliming agents neutralizes the process liquor pH, typical values after effective, thorough deliming will range from 6 to 9. Ammonium salt deliming pH values should be pH8 to 9, the deliming process can be done with acids that can be rapid in their pH adjustment. Buffering salts like ammonium salts predominated the 20th century, other weak acids can be used such as boric acid. Acetic, formic, lactic acid, Phosphoric Acid and carbonic acid, carbonic acid is used in a deliming process called carbon dioxide deliming. Strong acids such as acid and sulfuric acid can also be used
15.
Degreasing
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Degreasing, often called Defatting or fat trimming, is the removal of fatty acids from an object. In culinary science, degreasing is done with the intention of reducing the fat content of a meal, degreasing is often used by dieters, particularly those following low fat diets to reduce their fat consumption to induce weight loss. The energy content of 1 g of fat is 9 calories, while that of carbohydrates, hence, dieters often view decreasing fat consumption as an efficient way of losing weight without greatly sacrificing total volume of food. Those people who wish to reduce their level or fat intake. Fat trimming of a meal can be done during preparation by a variety of methods, the most common methods involving substituting food items or removal of naturally occurring fat and conservative addition of fat. Substituting fats is a method in which an ingredient is substituted by another ingredient. A common way of doing this is substituting saturated fatty acids with unsaturated fatty acids while cooking, for instance, olive oil can be used instead of butter for seasoning salad. Food items are also substituted to reduce fat content, for instance, instead of using eggs by using a whole egg, where the egg yolks are high in fat levels, egg whites can instead be used. Alternatively, skimmed milk or similar low fat products can be used as ingredients for cooking, many different foods can be degreased after preparation. Liquid foods that are high in fat, such as braising liquids, roasting juices and broths may have floating oil on top throughout, fat can be skimmed off the liquid with a small ladle, spoon, or cup as the liquid simmers and then discarded. This is done by placing the saucepan with only half of it on the source so that the liquid simmers only on one side. This pushes the fat to the side and makes it easier to lift off with the ladle. As braising liquids and broths simmer, they throw off more fat and protein and sometimes froth. In making slowly reduced liquids it may be ideal to wait for it to even longer. As an alternative to a ladle, a cup can be used to skim the fat off hot liquids. This is a plastic or glass cup that looks similar to a teapot. The liquid and juices are poured into the cup then poured out leaving the fat behind, degreasing cups come in various sizes. Refrigerating or freezing liquids until the fat congeals and solidifies can make the fat easier to remove with a spoon, some items such as roasted foods and other cooked food items, such as pizza can sometimes be oily and greasy
16.
Pickling
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Pickling is the process of preserving or expanding the lifespan of food by either anaerobic fermentation in brine or immersion in vinegar. The resulting food is called a pickle, or, to prevent ambiguity, the pickling procedure will typically affect the foods texture and flavor. In East Asia, vinaigrette is used as a pickling medium. Foods that are pickled include meats, fruits, eggs, another distinguishing characteristic is a pH of 4.6 or lower, which is sufficient to kill most bacteria. Pickling can preserve perishable foods for months, antimicrobial herbs and spices, such as mustard seed, garlic, cinnamon or cloves, are often added. If the food contains sufficient moisture, a pickling brine may be produced simply by adding dry salt, for example, German sauerkraut and Korean kimchi are produced by salting the vegetables to draw out excess water. Natural fermentation at room temperature, by lactic acid bacteria, produces the required acidity, other pickles are made by placing vegetables in vinegar. Unlike the canning process, pickling does not require that the food be completely sterile before it is sealed, the acidity or salinity of the solution, the temperature of fermentation, and the exclusion of oxygen determine which microorganisms dominate, and determine the flavor of the end product. When both salt concentration and temperature are low, Leuconostoc mesenteroides dominates, producing a mix of acids, alcohol, at higher temperatures Lactobacillus plantarum dominates, which produces primarily lactic acid. Many pickles start with Leuconostoc, and change to Lactobacillus with higher acidity, pickling began 4000 years ago using cucumbers native to India. This was used as a way to food for out-of-season use and for long journeys. Salt pork and salt beef were common staples for sailors before the days of steam engines, although the process was invented to preserve foods, pickles are also made and eaten because people enjoy the resulting flavors. Pickling may also improve the value of food by introducing B vitamins produced by bacteria. The term pickle is derived from the Dutch word pekel, meaning brine, in the U. S. and Canada, and sometimes Australia and New Zealand, the word pickle alone almost always refers to a pickled cucumber, except when it is used figuratively. It may also refer to types of pickles such as pickled onion, pickled cauliflower. In the UK, pickle, as in a cheese and pickle sandwich, may refer to Ploughmans pickle. South Asia has a variety of pickles, which are mainly made from varieties of mango, lemon, lime, goongura, tamarind and Indian gooseberry. Vegetables such as brinjal, carrots, cauliflower, tomato, bitter gourd, green tamarind, ginger, garlic, onion and these fruits and vegetables are generally mixed with ingredients like salt, spices, and vegetable oils and are set to mature in a moistureless medium
17.
Protein
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Proteins are large biomolecules, or macromolecules, consisting of one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, a linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide, short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides, or sometimes oligopeptides. The individual amino acid residues are bonded together by peptide bonds, the sequence of amino acid residues in a protein is defined by the sequence of a gene, which is encoded in the genetic code. In general, the code specifies 20 standard amino acids, however. Sometimes proteins have non-peptide groups attached, which can be called prosthetic groups or cofactors, proteins can also work together to achieve a particular function, and they often associate to form stable protein complexes. Once formed, proteins only exist for a period of time and are then degraded and recycled by the cells machinery through the process of protein turnover. A proteins lifespan is measured in terms of its half-life and covers a wide range and they can exist for minutes or years with an average lifespan of 1–2 days in mammalian cells. Abnormal and or misfolded proteins are degraded more rapidly due to being targeted for destruction or due to being unstable. Like other biological macromolecules such as polysaccharides and nucleic acids, proteins are essential parts of organisms, many proteins are enzymes that catalyse biochemical reactions and are vital to metabolism. Proteins also have structural or mechanical functions, such as actin and myosin in muscle and the proteins in the cytoskeleton, other proteins are important in cell signaling, immune responses, cell adhesion, and the cell cycle. In animals, proteins are needed in the diet to provide the essential amino acids that cannot be synthesized, digestion breaks the proteins down for use in the metabolism. Methods commonly used to study structure and function include immunohistochemistry, site-directed mutagenesis, X-ray crystallography, nuclear magnetic resonance. Most proteins consist of linear polymers built from series of up to 20 different L-α-amino acids, all proteinogenic amino acids possess common structural features, including an α-carbon to which an amino group, a carboxyl group, and a variable side chain are bonded. Only proline differs from this structure as it contains an unusual ring to the N-end amine group. The amino acids in a chain are linked by peptide bonds. Once linked in the chain, an individual amino acid is called a residue, and the linked series of carbon, nitrogen. The peptide bond has two forms that contribute some double-bond character and inhibit rotation around its axis, so that the alpha carbons are roughly coplanar
18.
Shrinkage (fabric)
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Shrinkage is the process in which a fabric becomes smaller than its original size, usually through the process of laundry. Novice users of modern laundry machines sometimes experience accidental shrinkage of garments, others may intentionally shrink a garment to their size. Some may purchase a garment one or more sizes larger in anticipation of shrinkage, for wool garments, shrinkage is due to scales on the fibers which heat, water and agitation cause to stick together. Other fabrics are stretched by mechanical forces during production, and can shrink slightly when heated, some clothes are pre-shrunk to avoid this problem
19.
Dyeing
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Dyeing is the process of adding color to textile products like fibers, yarns, and fabrics. Dyeing is normally done in a solution containing dyes and particular chemical material. After dyeing, dye molecules have uncut chemical bond with fiber molecules, the temperature and time controlling are two key factors in dyeing. There are mainly two classes of dye, natural and man-made, the primary source of dye, historically, has generally been nature, with the dyes being extracted from animals or plants. Since the mid-19th century, however, humans have produced artificial dyes to achieve a range of colors and to render the dyes more stable to resist washing. Different classes of dyes are used for different types of fiber and at different stages of the production process, from loose fibers through yarn. Acrylic fibers are dyed with basic dyes, while nylon and protein fibers such as wool and silk are dyed with acid dyes, cotton is dyed with a range of dye types, including vat dyes, and modern synthetic reactive and direct dyes. The word dye is from Middle English deie and from Old English dag, the first known use of the word dye was before the 12th century. The earliest dyed flax fibers have found in a prehistoric cave in the Republic of Georgia. In China, dyeing with plants, barks, and insects has been traced more than 5,000 years. Early evidence of dyeing comes from Sindh province in Pakistan, where a piece of cotton dyed with a dye was recovered from the archaeological site at Mohenjo-daro. The dye used in case was madder, which, along with other dyes such as indigo, was introduced to other regions through trade. The first synthetic dye was William Perkins mauveine in 1856, derived from coal tar, alizarin, the red dye present in madder, was the first natural pigment to be duplicated synthetically in 1869, a development which led to the collapse of the market for naturally grown madder. The development of new, strongly colored synthetic dyes followed quickly, dyes are applied to textile goods by dyeing from dye solutions and by printing from dye pastes. Methods include direct application and yarn dyeing and this renders the dye soluble so that it can be absorbed by the fiber since the insoluble dye has very little substantivity to the fiber. Direct dyes, a class of dyes largely for dyeing cotton, are water-soluble, most other classes of synthetic dye, other than vat and surface dyes, are also applied in this way. The term may also be applied to dyeing without the use of mordants to fix the dye once it is applied, mordants were often required to alter the hue and intensity of natural dyes and improve color fastness. Chromium salts were until recently used in dyeing wool with synthetic mordant dyes
20.
Whitening (leather processing)
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The leather manufacturing process is divided into three sub-processes, preparatory stages, tanning and crusting. All true leathers undergo these sub-processes. A further sub-process, surface coating may be added into the sequence, the list of operations that leathers undergo vary with the type of leather. The leather making process is in general restricted to batch processing, the operation flow has to follow the preparatory → tanning → crusting → surface coating sub-process order without deviation, but some of the sub-processes can be omitted to make certain leathers. The preparatory stages are when the hide/skin is prepared for tanning, during the preparatory stages many of the unwanted raw skin components are removed. Many options for pretreatment of the skin exist, not all of the options may be performed. Preparatory stages may include, preservation- the hide/skin is treated with a method which renders it temporarily imputrescible, soaking - water for purposes of washing or rehydration is reintroduced. Liming - unwanted proteins and opening up is achieved, unhairing - the majority of hair is removed. Fleshing - subcutaneous material is removed, splitting - the hide/skin is cut into two or more horizontal layers. Reliming - the hide/skin is further treated to achieve more opening up or more protein removal, frizing - physical removal of the fat layer inside the skin. Bleaching - chemical modification of dark pigments to yield a lighter coloured pelt. pickling - lowering of the pH value to the acidic region, must be done in the presence of salts. Pickling is normally done to help with the penetration of certain tanning agents, a large number of different tanning methods and materials can be used, the choice is ultimately dependent on the end application of the leather. The most commonly used tanning material is chromium, which leaves the leather, once tanned, a blue colour. The acidity of hides once they have finished pickling will typically be between pH of 2. 8-3.2, at this point the hides are loaded in a drum and immersed in a float containing the tanning liquor. The hides are allowed to soak and the tanning liquor slowly penetrates through the substance of the hide. Regular checks will be made to see the penetration by cutting the cross section of a hide, once an even degree of penetration is observed, the pH of the float is slowly raised in a process called basification. The pH of the leather when chrome tanned would typically finish somewhere between 3. 8-4.2, crusting is when the hide/skin is thinned, retanned and lubricated. Often a coloring operation is included in the crusting sub-process, the chemicals added during crusting have to be fixed in place
21.
Tumble finishing
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Tumble finishing, also known as tumbling or rumbling, is a technique for smoothing and polishing a rough surface on relatively small parts. In the field of metalworking, a process called barreling, or barrel finishing. For tumbling of rocks as a technique, a plastic or rubber-lined barrel is loaded with a consignment of rocks, all of similar or the same hardness, some abrasive grit. Silicon carbide grit is used, and water is a universal lubricant. The barrel is placed upon slowly rotating rails so that it rotates. The optimal speed of rotation depends on the size of the tumbler barrel, a well-chosen speed for stone polishing causes the rocks within the barrel to slide past each other, with the abrasive grit between them. The result of this depends on the coarseness of the abrasive, typically, a full tumble polish from rough rock to polish takes between 3–5 weeks, and is done in a minimum of 3 steps. Initially, the rocks are smoothed with a coarse grit, the idea behind the first step is to take rough rock or stone and grind it down into a form which is indistinguishable from the final product. This is followed by washing and then a stage of finer grits, before the use of a pre-polishing compound, a washing cycle with detergent to remove any grit on the stones. The final step is a stage using powdered polish, water. The precise tumbling time is determined by many factors, including the hardness of the rock, some people will tumble stones with rough grit for two, three or even four weeks to get their desired shapes out of the stones. There are two types of rock tumbling, barrel tumbling, and vibratory tumbling. Rotary tumbling is more common, simpler, quieter and less expensive than vibratory tumblers, there are two differentiating factors, however, that may lead one to use a vibratory tumbler. First, vibratory tumbler retain the shape of the rough rock. Thus, it is important to use vibratory tumbler to make faceted shapes, second, vibratory tumblers tend to process much faster than rotary tumblers, generally reducing the process time to half. This refers to cutting shapes from the rock, before tumbling. This gives more control over the piece, so shapes such as a tear drop can be produced. The technique is limited to rounded shapes
22.
Neatsfoot oil
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Neatsfoot oil is a yellow oil rendered and purified from the shin bones and feet of cattle. Neat in the name comes from an old English word for cattle. Neatsfoot oil is used as a conditioning, softening and preservative agent for leather, in the 18th century, it was also used medicinally as a topical application for dry scaly skin conditions. Prime neatsfoot oil or neatsfoot oil compound are used for a blend of pure neatsfoot oil and non-animal oils. Fat from warm-blooded animals normally has a melting point, becoming hard when cool –. This characteristic of neatsfoot oil allows it to soak easily into leather, modern neatsfoot oil is still made from cattle-based products, and is sometimes criticized for a tendency to speed oxidation of leather. This formulation does darken leather, which means that use on light-colored leather is likely to change its color, if mineral oil or other petroleum-based material is added, the product may be called neatsfoot oil compound. Some brands have also shown to be adulterated with rapeseed oil, soya oil. The addition of mineral oils may lead to rapid decay of non-synthetic stitching or speed breakdown of the leather itself. After cattle are slaughtered, the feet and lower leg bones, including the skin, the oil that is released is skimmed off, filtered and pressed. The first pressing is the highest grade, the second pressing produces a lower grade oil, neatsfoot oil is used on a number of leather products, although it has been replaced by synthetic products for certain applications. Items such as gloves, saddles, horse harnesses and other horse tack can be softened and conditioned with neatsfoot oil. If used on important historical objects, neatsfoot oil can oxidize with time and it also may leave an oily residue that can attract dust. On newer leather, it may cause darkening, thus may not be a product to use when the maintenance of a lighter shade is desired. Neatsfoot oil is more useful for use on working equipment. Neatsfoot oil is used to oil sign-writers brushes that have been used in oil-based paint, as this oil is non drying. Oiling the brushes reduces the buildup of pigment in the ferrule, neatsfoot oil of the highest grade is used as a lubricant. It is used in metalworking industries as a fluid for aluminium
23.
Tannin
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A tannin is an astringent, polyphenolic biomolecule that binds to and precipitates proteins and various other organic compounds including amino acids and alkaloids. The term tannin refers to the use of wood tannins from oak in tanning hides into leather, hence the words tan. The tannin compounds are distributed in many species of plants, where they play a role in protection from predation, and perhaps also as pesticides. The astringency from the tannins is what causes the dry and puckery feeling in the following the consumption of unripened fruit or red wine or tea. Likewise, the destruction or modification of tannins with time plays an important role when determining harvesting times, Tannins have molecular weights ranging from 500 to over 3,000 and up to 20,000. There are three classes of tannins, Shown below are the base unit or monomer of the tannin. Particularly in the flavone-derived tannins, the base shown must be heavily hydroxylated and polymerized in order to give the high molecular weight polyphenol motif that characterizes tannins, typically, tannin molecules require at least 12 hydroxyl groups and at least five phenyl groups to function as protein binders. Oligostilbenoids are oligomeric forms of stilbenoids and constitute a class of tannins, pseudo tannins are low molecular weight compounds associated with other compounds. They do not change color during the Goldbeaters skin test, unlike hydrolysable and condensed tannins, some examples of pseudo tannins and their sources are, Ellagic acid, gallic acid, and pyrogallic acid were first discovered by chemist Henri Braconnot in 1831. Julius Löwe was the first person to synthesize ellagic acid by heating gallic acid with arsenic acid or silver oxide, maximilian Nierenstein studied natural phenols and tannins found in different plant species. Working with Arthur George Perkin, he prepared ellagic acid from algarobilla and he suggested its formation from galloyl-glycine by Penicillium in 1915. Tannase is an enzyme that Nierenstein used to produce acid from gallotannins. He proved the presence of catechin in cocoa beans in 1931 and he showed in 1945 that luteic acid, a molecule present in the myrobalanitannin, a tannin found in the fruit of Terminalia chebula, is an intermediary compound in the synthesis of ellagic acid. At these times, molecule formulas were determined through combustion analysis, the discovery in 1943 by Martin and Synge of paper chromatography provided for the first time the means of surveying the phenolic constituents of plants and for their separation and identification. There was an explosion of activity in this field after 1945, none more so than that of Edgar Charles Bate-Smith and it is referred to as the White–Bate-Smith–Swain–Haslam definition. Tannins are distributed in species throughout the plant kingdom and they are commonly found in both gymnosperms as well as angiosperms. Mole studied the distribution of tannin in 180 families of dicotyledons and 44 families of monocotyledons, most families of dicot contain tannin-free species. To the family of the oak, Fagaceae, 73% of the species tested contain tannin, for those of acacias, Mimosaceae, only 39% of the species tested contain tannin, among Solanaceae rate drops to 6% and 4% for the Asteraceae
24.
Biomass
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Biomass is an industry term for getting energy by burning wood, and other organic matter. It has become popular among power stations, which switch from coal to biomass to comply with the law. Biomass most often refers to plants or plant-based materials that are not used for food or feed, as an energy source, biomass can either be used directly via combustion to produce heat, or indirectly after converting it to various forms of biofuel. Conversion of biomass to biofuel can be achieved by different methods which are classified into, thermal, chemical. Historically, humans have harnessed biomass-derived energy since the time people began burning wood to make fire. Even today, biomass is the source of fuel for domestic use in many developing countries. Biomass is all biologically-produced matter based in carbon, hydrogen and oxygen, the estimated biomass production in the world is 104.9 petagrams of carbon per year, about half in the ocean and half on land. Wood remains the largest biomass energy source today, examples include forest residues, yard clippings, wood chips, wood energy is derived by using lignocellulosic biomass as fuel. Harvested wood may be used directly as a fuel or collected from waste streams to be processed into pellet fuel or other forms of fuels. The largest source of energy from wood is pulping liquor or black liquor, in the second sense, biomass includes plant or animal matter that can be converted into fibers or other industrial chemicals, including biofuels. Based on the source of biomass, biofuels are classified broadly into two major categories, first-generation biofuels are derived from sources such as sugarcane and corn starch. Sugars present in this biomass are fermented to produce bioethanol, a fuel which can be used directly in a fuel cell to produce electricity or serve as an additive to gasoline. However, utilizing food-based resources for production only aggravates the food shortage problem. Second-generation biofuels, on the hand, utilize non-food-based biomass sources such as agriculture. These biofuels mostly consist of lignocellulosic biomass, which is not edible and is a waste for many industries. Despite being the alternative, economical production of second-generation biofuel is not yet achieved due to technological issues. These issues arise due to chemical inertness and structural rigidity of lignocellulosic biomass. Plant energy is produced by crops grown for use as fuel that offer high biomass output per hectare with low input energy
25.
Tanbark
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Tanbark is the bark of certain species of tree. It is traditionally used for tanning hides into leather, the words tannin, tanning, tan, and tawny are derived from the Medieval Latin tannare, to convert into leather. Bark mills are horse- or oxen-driven or water powered edge mills and were used in times to shred the tanbark to derive tannins for the leather industry. A barker was a person who stripped bark from trees to supply bark mills, in Europe, oak is a common source of tanbark. Quercitannic acid is the constituent found in oak barks. The bark is taken from branches and twigs in oak coppices and can be up to 4 mm thick, it is grayish-brown on the outside. In some areas of the United States, such as northern California, tanbark is often called mulch, in these areas, the word mulch may refer to peat moss or to very fine tanbark. In California, Lithocarpus densiflorus was used, in America, condensed tannins are also present in the bark of blackjack oak. In New York, on the slopes of Mount Tremper, hemlock bark was a source of tanbark during the 19th century. Around the Mediterranean Sea, sumach leaves and bark are used, in Africa and Australia, acacia bark is used by tanners
26.
Bark mill
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The powdered wood more quickly yields up the tannin required for the tanning process. The dried bark was often stored in bark houses, water-, steam-, horse- or ox- and wind-powered bark mills existed. Water-powered bark mills were sitting alongside rivers and leats were dug to bring water to the wheel, a barker was a person who stripped bark from trees to supply bark mills. Bark tanning or vegetable tanning is part of the ancient process of creating durable and it can be done to most types of skin, but it is usually reserved for tanning leathers from large and thick hides such as cattle, horses, and pigs. The leather produced has been used for saddles, canteens, stiff shoes, belts, wallets, holsters, harnesses, helmets, pouches, trunks, shields. It was also used as an part of bellows, hinges, wagon wheels. Vegetable tanned hide is flexible and is used for luggage and furniture, mineral tanning, being cheaper and faster, replaced the use of bark and mainly uses chromium Sulphate. Once the desired level of penetration of chrome into the substance is achieved, in the raw state chrome tanned skins are blue. Chrome tanning produces a leather which is excellent for use in handbags. Tawing uses alum and aluminium salts, together with egg yolk, flour, the leather becomes tawed by soaking in a warm potash alum and salts solution. The process increases the pliability, stretchability, softness, and quality of the leather, the addition of egg yolk and flour to the standard soaking solution further enhances its fine handling characteristics. Then, the leather is air dried for weeks, which allows it to stabilize. Tawing is used on pigskins and goatskins to create the whitest colour and it is marked on OS maps, and was powered by the combined Mains and Bath Burns with mill ponds indicated. The mill produced ground bark for use in the Beith Bath Lane tannery, later the mill became a furniture factory run by Matthew Pollock who applied the use of machinery to help with the manufacture of furniture in 1858. This site was one mile from the Beith town centre, the Glasgow & South Western Railway Company constructed a siding, known as Muirs siding for the convenience of transporting the finished products, etc. The site was isolated and inconvenient for the workers and was sold to Robert Balfour, who later built a new factory near Beith Town Station. The Muirs had been tanners for many generations and around 1791 John Muir and Sons, Tanners, Curriers, william Muir of Mains joined as a partner in 1846. Mill on the Fleet, in Gatehouse of Fleet, Castle Douglas, the water wheel on the gable end was used to drive the machinery to spin the cotton
27.
Boiled leather
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Boiled leather, sometimes called cuir bouilli, was a historical construction material for armour. It consists of leather, boiled in water. According to some sources, boiled oil and wax were used as well, the boiling causes the leather to become harder but also more brittle. The leather remains flexible for a time after boiling, allowing it to be molded into larger plates. Cuir bouilli has also employed to bind books. Water hardened leather for armour Boiled leather in wax Cuir Bouilli/Hardened Leather FAQ
28.
Wax
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Waxes are a diverse class of organic compounds that are hydrophobic, malleable solids near ambient temperatures. They include higher alkanes and lipids, typically with melting points above about 40 °C, waxes are insoluble in water but soluble in organic, nonpolar solvents. Natural waxes of different types are produced by plants and animals, waxes are organic compounds that characteristically consist of long alkyl chains. They may also include various groups such as fatty acids, primary and secondary long chain alcohols, unsaturated bonds, aromatics, amides, ketones. They frequently contain fatty acid esters as well, synthetic waxes are often long-chain hydrocarbons that lack functional groups. Waxes are synthesized by plants and animals. Those of animal origin typically consist of wax esters derived from a variety of carboxylic acids, in waxes of plant origin characteristic mixtures of unesterified hydrocarbons may predominate over esters. The composition depends not only on species, but also on location of the organism. The most commonly known animal wax is beeswax, but other insects secrete waxes, a major component of the beeswax used in constructing honeycombs is the ester myricyl palmitate which is an ester of triacontanol and palmitic acid. Its melting point is 62-65 °C, spermaceti occurs in large amounts in the head oil of the sperm whale. One of its constituents is cetyl palmitate, another ester of a fatty acid. Lanolin is a wax obtained from wool, consisting of esters of sterols, plants secrete waxes into and on the surface of their cuticles as a way to control evaporation, wettability and hydration. From the commercial perspective, the most important plant wax is carnauba wax, containing the ester myricyl cerotate, it has many applications, such as confectionery and other food coatings, car and furniture polish, floss coating, and surfboard wax. Other more specialized vegetable waxes include candelilla wax and ouricury wax, plant and animal based waxes or oils can undergo selective chemical modifications to produce waxes with more desirable properties than are available in the unmodified starting material. This approach has relied on green chemistry approaches including olefin metathesis and enzymatic reactions, although many natural waxes contain esters, paraffin waxes are hydrocarbons, mixtures of alkanes usually in a homologous series of chain lengths. These materials represent a significant fraction of petroleum and they are refined by vacuum distillation. Paraffin waxes are mixtures of saturated n- and iso- alkanes, naphthenes, a typical alkane paraffin wax chemical composition comprises hydrocarbons with the general formula CnH2n+2, such as Hentriacontane, C31H64. The degree of branching has an important influence on the properties, millions of tons of paraffin waxes are produced annually
29.
Armour
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Personal armour is used to protect soldiers and war animals. Vehicle armour is used on warships and armoured fighting vehicles, a second use of the term armour describes armoured forces, armoured weapons, and their role in combat. After the evolution of armoured warfare, mechanised infantry and their weapons came to be referred to collectively as armour, the word armour began to appear in the Middle Ages as a derivative of Old French. It is dated from 1297 as a mail, defensive covering worn in combat, the word originates from the Old French armure, itself derived from the Latin armatura meaning arms and/or equipment, with the root armare meaning arms or gear. Armour has been used throughout recorded history and it has been made from a variety of materials, beginning with rudimentary leather protection and evolving through mail and metal plate into todays modern composites. For much of history the manufacture of metal personal armour has dominated the technology. Its production was influential in the revolution, and furthered commercial development of metallurgy. Armour was the single most influential factor in the development of firearms, significant factors in the development of armour include the economic and technological necessities of its production. For instance, plate armour first appeared in Medieval Europe when water-powered trip hammers made the formation of plates faster and cheaper, also, modern militaries usually do not equip their forces with the best armour available because it would be prohibitively expensive. The samurai warriors of feudal Japan utilised many types of armour for hundreds of years up to the 19th century, Japanese lamellar armour passed through Korea and reached Japan around the 5th century. These early Japanese lamellar armours took the form of a sleeveless jacket, armour did not always cover all of the body, sometimes no more than a helmet and leg plates were worn. The rest of the body was protected by means of a large shield. Examples of armies equipping their troops in this fashion were the Aztecs, in East Asia many types of armour were commonly used at different times by various cultures including, scale armour, lamellar armour, laminar armour, plated mail, mail, plate armour and brigandine. Around the dynastic Tang, Song, and early Ming Period, cuirasses and plates were also used, the Chinese, during that time used partial plates for important body parts instead of covering their whole body since too much plate armour hinders their martial arts movement. The other body parts were covered in cloth, leather, lamellar, in pre-Qin dynasty times, leather armour was made out of various animals, with more exotic ones such as the rhinoceros. Mail, sometimes called chainmail, made of interlocking iron rings is believed to have first appeared some time after 300 BC and its invention is credited to the Celts, the Romans were thought to have adopted their design. Gradually, small plates or discs of iron were added to the mail to protect vulnerable areas. Hardened leather and splinted construction were used for arm and leg pieces, the coat of plates was developed, an armour made of large plates sewn inside a textile or leather coat
30.
Chromium(III) sulfate
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Chromium sulfate usually refers to the inorganic compounds with the formula Cr23. x, where x can range from 0 to 18. Additionally, ill-defined but commercially important basic chromium sulfates are known and these salts are usually either violet or green solids that are soluble in water. Three chromium sulfates are well characterized, Anhydrous chromium sulfate, Cr23, is a solid that dissolves in water upon addition of a reducing agent. Hydrated chromium sulfate, Cr23. 18H2O, is a solid that readily dissolves in water to give the metal aquo complex. The formula of this compound can be more descriptively as 23. 6H2O. Six of the 18 water molecules in this unit are water of crystallization. Hydrated chromium sulfate, Cr23.15, is a solid that also readily dissolves in water. It is obtained by heating the 18H2O material above 70 °C, further heating yields the anhydrous sulfate. A variety of other chromium sulfates are known, but also contain hydroxide or oxide ligands, most important commercially is basic chromium sulfate, which is thought to be SO4. It results from the neutralization of the hexahydrates. It is associated with environmental damage, other chromium hydroxides have been reported. The most useful source of sulfate are the Cr wastes from the chromate oxidation of various organic compounds. Anthroquinone and quinone are produced by on large scale by treatment of anthracene, a chromium oxide coproduct is generated which is readily extracted into sulfuric acid. Evaporation of these acidic solutions affords the hydrate salt described above, the hydrated salts of chromium sulfate can also be produced, albeit impure, by extraction of various other chromium compounds, but these routes are not economically viable. Extraction of chromite ore with sulfuric acid in the presence of some chromate gives solutions of chromium sulfate contaminated with metal ions. Similarly, dissolution of chrome alloys gives chromium sulfate together with ferrous sulfate, basic chromium sulfate is produced from chromate salts by reduction with sulfur dioxide, although other methods exist. The reduction could formally be written, Na2Cr2O7 +3 SO2 + H2O → Cr23 + 2NaOH Since 33% of the charges are due to hydroxy ions the basicity is 33%. Products with higher basicities, e. g.42 or 50% may be obtained by the addition of sodium carbonate, the sodium sulfate is often left in the technical product since it is inert with respect to the tanning process
31.
Chromium
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Chromium is a chemical element with symbol Cr and atomic number 24. It is the first element in Group 6 and it is a steely-grey, lustrous, hard and brittle metal which takes a high polish, resists tarnishing, and has a high melting point. The name of the element is derived from the Greek word χρῶμα, chrōma, meaning color, Chromium metal is of high value for its high corrosion resistance and hardness. A major development was the discovery that steel could be highly resistant to corrosion and discoloration by adding metallic chromium to form stainless steel. Stainless steel and chrome plating together comprise 85% of the commercial use, trivalent chromium ion is an essential nutrient in trace amounts in humans for insulin, sugar and lipid metabolism, although the issue is debated. While chromium metal and Cr ions are not considered toxic, hexavalent chromium is toxic and carcinogenic, abandoned chromium production sites often require environmental cleanup. Chromium is remarkable for its properties, it is the only elemental solid which shows antiferromagnetic ordering at room temperature. Above 38 °C, it changes to paramagnetic, Chromium metal left standing in air is passivated by oxidation, forming a thin, protective, surface layer. This layer is a structure only a few molecules thick. It is very dense, and prevents the diffusion of oxygen into the underlying metal and this is different from the oxide that forms on iron and carbon steel, through which elemental oxygen continues to migrate, reaching the underlying material to cause incessant rusting. Passivation can be enhanced by short contact with oxidizing acids like nitric acid, passivated chromium is stable against acids. Passivation can be removed with a reducing agent that destroys the protective oxide layer on the metal. Chromium metal treated in this way readily dissolves in weak acids, Chromium, unlike such metals as iron and nickel, does not suffer from hydrogen embrittlement. However, it suffer from nitrogen embrittlement, reacting with nitrogen from air. Chromium is the 22nd most abundant element in Earths crust with a concentration of 100 ppm. Chromium compounds are found in the environment from the erosion of chromium-containing rocks, Chromium is mined as chromite ore. About two-fifths of the ores and concentrates in the world are produced in South Africa, while Kazakhstan, India, Russia. Untapped chromite deposits are plentiful, but geographically concentrated in Kazakhstan, although rare, deposits of native chromium exist
32.
Glutaraldehyde
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Glutaraldehyde, sold under the brandname Glutaral among others, is a disinfectant and medication. As a disinfectant it is used to sterilize surgical instruments and other areas, as a medication it is used to treat warts on the bottom of the feet. It is applied as a liquid, if exposed to large amounts nausea, headache, and shortness of breath may occur. Protective equipment is recommended when used, Glutaraldehyde is effective against a range of microorganisms including spores. It works by a number of mechanisms, Glutaraldehyde came into medical use in the 1960s. It is on the World Health Organizations List of Essential Medicines, the wholesale cost in the developing world is about 1.50 to 7.40 USD per liter of 2% solution. It is sold under a number of names including Cidex. There are a number of commercial uses such as leather tanning. Virtually all applications of glutaraldehyde exploit its high reactivity toward proteins, being nonvolatile and bifunctional, glutaraldehyde is often preferred to the less expensive formaldehyde. It reacts with amines, amides, and thiol groups in proteins, a glutaraldehyde solution of 0. 1% to 1. 0% concentration may be used as a biocide for system disinfection and as a preservative for long term storage. It is a sterilant, killing endospores in addition to many microorganisms, Glutaraldehyde is a component of hydraulic fracturing fracking fluid. It is included in the additive called Alpha 1427, as a biocide, Glutaraldehyde is pumped as a liquid additive with the fracturing fluid to reduce or eliminate this source of formation and fracture conductivity damage. Glutaraldehyde is used in applications as an amine-reactive homobifunctional crosslinker and fixative prior to SDS-PAGE, staining. A second fixative procedure uses osmium tetroxide to crosslink and stabilize cell, fixation is usually followed by dehydration of the tissue in ethanol or acetone, followed by embedding in an epoxy resin or acrylic resin. In a related application, glutaraldehyde is sometimes employed in the tanning of leather, a solution of glutaraldehyde, typically of 10% w/w, is sold under various trade names to remove common and plantar warts. It is said to inactivate viruses and bacteria, and to dry the skin, trade names include Diswart Solution and Glutarol. As a strong sterilant, glutaraldehyde is toxic and a strong irritant, there is no evidence of carcinogenic activity. It is a compound with the formula CH22
33.
Chamois leather
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Chamois leather — is a type of porous leather, traditionally the skin of the chamois, a type of European mountain goat but today it is made almost exclusively from the flesh split of a sheepskin. The leather is favored for its gentle, non-abrasive composition and absorption properties, in the United States, the term chamois without any qualification is restricted to the flesh split of the sheep or lambskin tanned solely with oils. Chamois leather is often counterfeited with goat or pig skin, the practice of which is a particular profession called by the French chamoiser and it was discovered that when tanned in the local cod oil of nearby Biarritz, the result was a material of unprecedented absorbency. This leather was fashioned into soft white gloves designed for carriage footmen and this industry usage later transferred to the chauffeurs of the horseless carriages invented in the early 1900s. Genuine chamois leather has almost no abrasive properties, and can be used as a very absorbent drying material for any automobile surface and this has made it a popular product for car cleaning and drying. The elasticity of the pores, which are very close. Its water absorbency makes it good for other uses, such as in cycling shorts and it was also used in purifying mercury, which is done by passing it through the pores of the skin. When soaked with gasoline, chamois will not allow water to pass through its surface fibers. This property is used to fuel that has been stored in drums prone to ingress of water. The technique is to provide a large-mouthed funnel with a wide outlet surface that supports a woven wire base, the lower part of the funnel is tapered to fit the receptacle or tank-filler aperture. A suitably sized chamois skin is soaked in fuel and placed over the grid in the funnel and brought up the sides, forming a bowl. Fuel can then be pumped into the top of the funnel by the fuel dispenser, the process can be stopped to lift out the assembly from the tank and the trapped water removed so that the job can be continued. Chamois leather is used thus as a filter by boaters, auto detailers—and aircraft refuellers. Widely used for drying and buffing vehicles, such as cars and vans, small pieces of chamois leather are commonly used as blending tools by artists drawing with charcoal. The leather blends the charcoal more softly and cleanly than the artists fingers, the chamois is also used to lighten the drawing by removing some charcoal in a more subtle and nuanced way than most erasers could. The charcoal can be washed from the leather using soap and water, divers use towels made of chamois leather to dry themselves between jumps, as they can be quickly dried by squeezing them
34.
Aluminium
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Aluminium or aluminum is a chemical element in the boron group with symbol Al and atomic number 13. It is a silvery-white, soft, nonmagnetic, ductile metal, Aluminium metal is so chemically reactive that native specimens are rare and limited to extreme reducing environments. Instead, it is combined in over 270 different minerals. The chief ore of aluminium is bauxite, Aluminium is remarkable for the metals low density and its ability to resist corrosion through the phenomenon of passivation. Aluminium and its alloys are vital to the industry and important in transportation and structures, such as building facades. The oxides and sulfates are the most useful compounds of aluminium, despite its prevalence in the environment, no known form of life uses aluminium salts metabolically, but aluminium is well tolerated by plants and animals. Because of these salts abundance, the potential for a role for them is of continuing interest. Aluminium is a soft, durable, lightweight, ductile. It is nonmagnetic and does not easily ignite, a fresh film of aluminium serves as a good reflector of visible light and an excellent reflector of medium and far infrared radiation. The yield strength of aluminium is 7–11 MPa, while aluminium alloys have yield strengths ranging from 200 MPa to 600 MPa. Aluminium has about one-third the density and stiffness of steel and it is easily machined, cast, drawn and extruded. Aluminium atoms are arranged in a cubic structure. Aluminium has an energy of approximately 200 mJ/m2. Aluminium is a thermal and electrical conductor, having 59% the conductivity of copper. Aluminium is capable of superconductivity, with a critical temperature of 1.2 kelvin. Aluminium is the most common material for the fabrication of superconducting qubits, the strongest aluminium alloys are less corrosion resistant due to galvanic reactions with alloyed copper. This corrosion resistance is reduced by aqueous salts, particularly in the presence of dissimilar metals. In highly acidic solutions, aluminium reacts with water to form hydrogen, primarily because it is corroded by dissolved chlorides, such as common sodium chloride, household plumbing is never made from aluminium
35.
Salt
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Salt is present in vast quantities in seawater, where it is the main mineral constituent. The open ocean has about 35 grams of solids per litre, Salt is essential for life in general, and saltiness is one of the basic human tastes. The tissues of animals contain larger quantities of salt than do plant tissues, Salt is one of the oldest and most ubiquitous food seasonings, and salting is an important method of food preservation. Salt was also prized by the ancient Hebrews, the Greeks, the Romans, the Byzantines, the Hittites, Egyptians, and the Indians. Salt became an important article of trade and was transported by boat across the Mediterranean Sea, along specially built salt roads, the scarcity and universal need for salt has led nations to go to war over it and use it to raise tax revenues. Salt is used in ceremonies and has other cultural significance. Salt is processed from salt mines, or by the evaporation of seawater or mineral-rich spring water in shallow pools. Its major industrial products are caustic soda and chlorine, and is used in industrial processes including the manufacture of polyvinyl chloride, plastics, paper pulp. Of the annual production of around two hundred million tonnes of salt, only about 6% is used for human consumption. Other uses include water conditioning processes, de-icing highways, and agricultural use, edible salt is sold in forms such as sea salt and table salt which usually contains an anti-caking agent and may be iodised to prevent iodine deficiency. As well as its use in cooking and at the table, sodium is an essential nutrient for human health via its role as an electrolyte and osmotic solute. Excessive salt consumption can increase the risk of diseases, such as hypertension, in children. Such health effects of salt have long been studied, accordingly, numerous world health associations and experts in developed countries recommend reducing consumption of popular salty foods. The World Health Organization recommends that adults should consume less than 2,000 mg of sodium, humans have always tended to build communities either around sources of salt, or where they can trade for it. All through history the availability of salt has been pivotal to civilization, the word salary comes from the Latin word for salt because the Roman Legions were sometimes paid in salt. The Natron Valley was a key region that supported the Egyptian Empire to its north, because it supplied it with a kind of salt that came to be called by its name, natron. Even before this, what is now thought to have been the first city in Europe is Solnitsata, in Bulgaria, even the name Solnisata means salt works. A very ancient salt-works operation has been discovered at the Poiana Slatinei archaeological site next to a spring in Lunca, Neamț County
36.
Patina
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Patina is a thin layer that variously forms on the surface of stone, on copper, bronze and similar metals, on wooden furniture, or any such acquired change of a surface through age and exposure. Patinas can provide a covering to materials that would otherwise be damaged by corrosion or weathering. They may also be aesthetically appealing, Patina also refers to accumulated changes in surface texture and colour that result from normal use of an object such as a coin or a piece of furniture over time. Archaeologists also use the term patina to refer to a layer that develops over time that is due to a range of complex factors on flint tools. This has led stone tool analysts in recent times to generally prefer the term cortification as a term to describe the process than patination. It also refers to development as the result of weathering of a layer, called cortex by geologists. The word patina comes from the Latin for shallow dish, figuratively, patina can refer to any fading, darkening or other signs of age, which are felt to be natural or unavoidable. The chemical process by which a patina forms is called patination, in clean air rural environments, the patina is created by the slow chemical reaction of copper with carbon dioxide and water, producing a basic copper carbonate. In industrial and urban air environments containing sulfurous acid rain from coal-fired power plants or industrial processes, a patina layer takes many years to develop under natural weathering. Buildings in damp coastal/marine environments will develop patina layers faster than ones in dry inland areas, facade cladding with alloys of copper, e. g. brass or bronze, will weather differently from pure copper cladding. Even a lasting gold colour is possible with copper-alloy cladding, for example Colston Hall in Bristol, or the Novotel at Paddington Central, often, antique and well-used firearms will develop a patina on the steel after the bluing, parkerizing, or other finish has worn. Firearms in this state are considered more valuable than ones that have been re-blued or parkerized. The patina protects the firearm from the more damaging rust that would occur were the patina to be polished off, the process is often called distressing. A wide range of chemicals, both household and commercial, can give a variety of patinas and they are often used by artists as surface embellishments either for color, texture, or both. Patination composition varies with the elements and these will determine the color of the patina. For copper alloys, such as bronze, exposure to chlorides leads to green, the basic palette for patinas on copper alloys includes chemicals like ammonium sulfide, liver of sulfur, cupric nitrate and ferric nitrate. For artworks, patination is often accelerated by applying chemicals with heat. Colors range from matte sandstone yellow to deep blues, greens, whites, reds, some patina colors are achieved by the mixing of colors from the reaction with the metal surface with pigments added to the chemicals
37.
Aniline leather
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Aniline leather is a type of leather dyed exclusively with soluble dyes without covering the surface with a topcoat paint or insoluble pigments. The resulting product retains the natural surface with the grain, i. e. visible pores. For this reason, aniline leather is one of the most precious finishing in leather manufacturing, originally, the dyes used for this process were synthesized from aniline through chemical reactions. These dyes used to be called aniline dyes or tar dyes, typically, leather is dyed both for aesthetic reasons and to conceal blemishes. The dye colours leather without producing the surface of pigmented leather. Any visible variations on the surface of the undyed leather such as natural blemishes will remain visible, there are different kinds of aniline leather, but the same kinds of dyes are used in the process. The dyes used are clear and transparent chemicals that allow the structure of the leather to be seen. These dyes show the texture, but do not protect the leather from damage. Aniline leather may be referred to as full aniline or full sauvage leather to differentiate between this dye treatment and variants, semi-aniline leather is produced through a very similar process to full-aniline, but has a thin protective top coat added to protect it from wear and staining. Pull-up aniline leather has additional oil or wax applied to the leather to give it a distressed look
38.
Nubuck
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Nubuck is top-grain cattle leather that has been sanded or buffed on the grain side, or outside, to give a slight nap of short protein fibers, producing a velvet-like surface. It is resistant to wear, and may be white or coloured, nubuck is similar to suede, but is created from the outer side of a hide, giving it more strength and thickness and a fine grain. It is generally more expensive than suede, and must be coloured or dyed heavily to cover up the sanding and stamping process, nubuck characteristics are similar to aniline leather. It is soft to the touch, scratches easily, and water drops darken it temporarily, the word nubuck probably comes from new + buck
39.
Suede
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Suede /ˈsweɪd/ is a type of leather with a napped finish, commonly used for jackets, shoes, shirts, purses, furniture and other items. The term comes from the French gants de Suède, which literally means gloves from Sweden, suede is made from the underside of the animal skin, which is softer and more pliable than though not as durable as the outer flesh layer. Suede leather is made from the underside of the skin, primarily from lamb, although goat, calf, splits from thick hides of cow and deer are also sueded, but, due to the fiber content, have a shaggy nap. Because suede does not include the exterior skin layer, suede is less durable. Its softness, thinness, and pliability make it suitable for clothing and delicate uses, suede was originally used for womens gloves, suede leather is also popular in upholstery, shoes, bags, and other accessories, and as a lining for other leather products. Due to its nature and open pores, suede may become dirty. Fabrics are often manufactured with a brushed or napped finish to resemble suede leather and these products often provide a similar look and feel to suede, but have advantages such as increased liquid or stain resistance, and may appeal to consumers who prefer a non-animal product. Sueded silk, sueded cotton and similar sueded fabrics are brushed, sanded or chemically treated for extra softness, suede yarns are generally thick and plush. Microsuede is a microfiber knit blend fabric with a soft finish and it has a great deal of stretch, and is very popular in upholstery as well as garments. Nubuck Ultrasuede Voris, 1930s-40s American fashion designer who worked exclusively in suede, the Journal of the American Leather Chemists Association. Clean It Fast, Clean It Right, The Ultimate Guide to Making Absolutely Everything You Own Sparkle & Shine, the Ultimate Guide to Skinning and Tanning, A Complete Guide to Working with Pelts, Fur, and Leather. The Complete Book of Tanning Skins and Furs, goldstein-Lynch, Ellen, Sarah Mullins, Nicole Malone. Making Leather Handbags and Other Stylish Accessories, conservation of Leather and Related Materials. Scholarly Publishing Office, University of Michigan Library, the Chemistry and Technology of Leather. American Chemical Society, Krieger Publishing Co, parker, Sybil P. McGraw-Hill Encyclopedia of Science & Technology, An International Reference Work
40.
Bicast leather
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Bicast leather is a material made with a split leather backing covered with a layer of polyurethane that is applied to the surface and then embossed. Because it is used for the backing, the leather portion of this material is generally not visible in finished goods made from bicast. Bicast was originally made for the industry for glossy shoes. The resulting product has an artificially consistent texture that is easier to clean and maintain, when used for footwear, it cannot be considered equal to conventional leather as it lacks the strength, breatheability, and durability of the natural product. Furniture made with bicast exhibits none of the associated with aniline leather. With constant use, the layer may crack and split free of its backing. Modern technology enables up to four stratified layers being taken from a single hide, the leather used in the backing of bicast is a thin layer, remaining after other layers have been removed for traditional leather work. Furniture manufacturers say that the benefit of bicast leather is its surface appearance at a low price. Lower grades of leather can be used during the process, and treating with polyurethane gives a uniform shine. Bicast leather looks best, they say, on furniture with taut seat cushions and pillows and it can easily be cleaned with a damp cloth. New bicast leather furniture can have an odor, but this typically dissipates about a week after the piece is exposed to air. Alcantara Artificial leather Bonded leather Durasof Presstoff Ultrasuede
41.
Patent leather
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Patent leather is a type of coated leather that has a very glossy, shiny finish. The coating process was introduced to the United States and improved by inventor Seth Boyden of Newark, New Jersey in 1818, boydens process, which he did not patent, used a linseed oil–based lacquer coating. Modern patent leather usually has a plastic coating, in general, patent leather begins as a superior grade of fine grain leather that undergoes a process to achieve the glossy look. However, patent leather primarily owes its popularity to Seth Boyden, reverse engineering the European patent leather, he ultimately discovered a way to produce his own patent leather. Using a formula that was based on a series of using layers of linseed oil-based coats. Boyden’s efforts resulted in the production of leather that quickly caught on as a complement for formal dress. Ironically, Boyden never patented his inventive process, successive coats of this mixture are applied, the skin being allowed to dry and the surface ground down with pumice-stone after each coat. Then the skins are blackened again with a fluid black mixed with turpentine, and hung up to dry again. After the skins have been allowed to settle, being laid in a pile for about a time, or longer if possible. A baking follows in an oven of moderate heat, the temperature is gradually raised and the baking continued three days. Exposure to the sun for ten hours completes the process, recently American manufacturers have been making patent leather from chrome-tanned skins. The product is different, as is also the process employed. Later, the substitution of plastics for multiple treatments with linseed oil allowed patent leather to be produced more cheaply, eventually, synthetic resins further simplified the process and cut production costs even further, making mass production of patent leather possible. In the UK fashion trends of the 1960s, shoes, boots, Patent shoes were available in red, white, blue, hot pink, orange, green and yellow, as well and black and white. Characterized by a finish that catches the light, patent leather comes in all colors just like regular leather. In addition to the finish, patent leather is also virtually waterproof. The visual aspects of patent leather have made it a material for formal accessories. Patent leather is sometimes confused with poromeric imitation leathers such as DuPonts Corfam and Kurarays Clarino, Patent leather and poromerics are cleaned in a similar way
42.
Seth Boyden
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Seth Boyden was an American inventor. He was born in Foxboro, Massachusetts, on November 17,1798 and he had a brother, Uriah A. Boyden. He worked as a watchmaker and moved to Newark, New Jersey, Boyden perfected the process for making patent leather, created malleable iron, invented a nail-making machine, and built his own steamboat. He is also credited with having invented a cut off switch for steam engines, at the time of his death, he told friends that he had, even at that time, enough experiments on hand to last two whole lifetimes. Using a formula that was based on a series of using layers of linseed oil-based coats. Boyden’s efforts resulted in the production of leather that quickly caught on as a complement for formal dress. Ironically, Boyden never patented his inventive patent leather process, Boyden began his work with malleable iron in 1820, when he was 32 years old. From observing the behavior of iron that stuck to the walls of his grandfathers forge and he completed his research in 1826, and won an award from the Franklin Institute in Philadelphia two years later, who noted that Boydens annealed cast iron specimen No. This invention, now called blackheart iron, is one of the most important contributions to metallurgy by an American, several sources state that Boyden made the first American daguerreotype and this statement appears on a plaque at the base of a Boyden statue in Newarks Washington Park. While it has long accepted that D. W. A daguerrean camera built by Boyden still exists in the collection of the Newark Museum, Boyden rarely patented his inventions, preferring instead to take individual contracts and to build and sell off businesses. He did make large sums from this, but not enough to support his research, during the last 15 years of his life, Boyden lived in near-poverty in Hilton, New Jersey and developed a hybrid strawberry known as the Hilton strawberry. Seth Boydens name is found on a school in Maplewood, New Jersey. Additionally, a statue of Boyden stands in Newarks Washington Park and this statue is the first one raised in the United States which honored an engineer. Seth Boyden at Find a Grave Remembering the forgotten Seth Boyden at Google News Archive
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