Pulp is a lignocellulosic fibrous material prepared by chemically or mechanically separating cellulose fibres from wood, fiber crops, waste paper, or rags. Many kinds of paper are made from wood with nothing else mixed into them; this includes newspapers and toilet paper. Pulp is one of the most abundant raw materials. Pulp for papermaking was produced by macerating mulberry bark as early as the 2nd century in Han dynasty China, where the invention of paper is traditionally attributed to Cai Lun. Lu Ji, in his 3rd century commentary on the Classic of Poetry, mentions that people residing south of the Yangtze River would traditionally pound mulberry bark to make paper or clothing. By the 6th century, the mulberry tree was domesticated by farmers in China for the purpose of producing pulp to be used in the papermaking process. In addition to mulberry, pulp was made from bamboo, hibiscus bark, blue sandalwood and cotton. Papermaking using pulp made from hemp and linen fibers from tattered clothing, fishing nets and fabric bags spread to Europe in the 13th century, with an ever-increasing use of rags being central to the manufacture and affordability of rag paper, a factor in the development of printing.
By the 1800s, demand exceeding the available supply of rags, the manual labor of papermaking resulted in paper being still a pricey product. Using wood pulp to make paper is a recent innovation, concurrent to the invention of automatic papermaking machines, both together resulting in paper and cardboard becoming an inexpensive commodity in modern times. Although the first use of paper made from wood pulp dates from 1800, as seen in some pages of a book published by Matthias Koops that year in London, large-scale wood paper production began with the development of mechanical pulping in Germany by Friedrich Gottlob Keller in the 1840s, by the Canadian inventor Charles Fenerty in Nova Scotia, Chemical processes followed, first with J. Roth's use of sulfurous acid to treat wood by Benjamin Tilghman's U. S. patent on the use of calcium bisulfite, Ca2, to pulp wood in 1867. A decade the first commercial sulfite pulp mill was built, in Sweden, it was based on work by Carl Daniel Ekman. By 1900, sulfite pulping had become the dominant means of producing wood pulp, surpassing mechanical pulping methods.
The competing chemical pulping process, the sulfate, or kraft, was developed by Carl F. Dahl in 1879; the invention of the recovery boiler, by G. H. Tomlinson in the early 1930s, allowed kraft mills to recycle all of their pulping chemicals. This, along with the ability of the kraft process to accept a wider variety of types of wood and to produce stronger fibres, made the kraft process the dominant pulping process, starting in the 1940s. Global production of wood pulp in 2006 was 175 million tons. In the previous year, 63 million tons of market pulp was sold, with Canada being the largest source at 21 percent of the total, followed by the United States at 16 percent; the wood fiber sources required for pulping are "45% sawmill residue, 21% logs and chips, 34% recycled paper". Chemical pulp made up 93 percent of market pulp; the timber resources used to make wood pulp are referred to as pulpwood. While in theory, any tree can be used for pulp-making, coniferous trees are preferred because the cellulose fibers in the pulp of these species are longer, therefore make stronger paper.
Some of the most used softwood trees for paper making include spruce, fir and hemlock, hardwoods such as eucalyptus and birch. There is increasing interest in genetically modified tree species, because of several major benefits these can provide, such as increased ease of breaking down lignin and increased growth rate. A pulp mill is a manufacturing facility that converts wood chips or other plant fibre source into a thick fiberboard which can be shipped to a paper mill for further processing. Pulp can be manufactured using mechanical, semi-chemical or chemical methods; the finished product may be either non-bleached, depending on the customer requirements. Wood and other plant materials used to make pulp contain three main components: cellulose fibers and hemicelluloses; the aim of pulping is to break down the bulk structure of the fibre source, be it chips, stems or other plant parts, into the constituent fibres. Chemical pulping achieves this by degrading the lignin and hemicellulose into small, water-soluble molecules which can be washed away from the cellulose fibres without depolymerizing the cellulose fibres.
The various mechanical pulping methods, such as groundwood and refiner mechanical pulping, physically tear the cellulose fibres one from another. Much of the lignin remains adhering to the fibres. Strength is impaired. There are a number of related hybrid pulping methods that use a combination of chemical and thermal treatment to begin an abbreviated chemical pulping process, followed by a mechanical treatment to separate the fibres; these hybrid methods include thermomechanical pulping known as TMP, chemithermomechanical pulping known as CTMP. The chemical and thermal treatments reduce the amount of energy subsequently required by the mechanical treatment, al
Pinus strobus denominated the eastern white pine, northern white pine, white pine, Weymouth pine, soft pine is a large pine native to eastern North America. It occurs from Newfoundland, Canada west through the Great Lakes region to southeastern Manitoba and Minnesota, United States, south along the Appalachian Mountains and upper Piedmont to northernmost Georgia and very in some of the higher elevations in northeastern Alabama; the Native American Haudenosaunee denominated it the "Tree of Peace". It is known as the "Weymouth pine" in the United Kingdom, after Captain George Weymouth of the British Royal Navy, who brought its seeds to England from Maine in 1605. Pinus strobus is found in the nearctic temperate broadleaf and mixed forests biome of eastern North America, it prefers well-drained or sandy soils and humid climates, but can grow in boggy areas and rocky highlands. In mixed forests, this dominant tree towers over many others, including some of the large broadleaf hardwoods, it provides food and shelter for numerous forest birds, such as the red crossbill, small mammals such as squirrels.
Eastern white pine forests covered much of north-central and north-eastern North America. Only one percent of the old-growth forests remain after the extensive logging operations of the 18th century to early 20th century. Old growth forests, or virgin stands, are protected in Great Smoky Mountains National Park. Other protected areas with known virgin forests, as confirmed by the Eastern Native Tree Society, include Algonquin Provincial Park, Quetico Provincial Park, Algoma Highlands in Ontario, Canada. Small groves or individual specimens of old growth eastern white pines are found across the range of the species in the USA, including in Ordway Pines, Maine. Many sites with conspicuously large specimens represent advanced old field ecological succession; the tall stands in Mohawk Trail State Forest and William Cullen Bryant Homestead in Massachusetts are examples. As an introduced species, Pinus strobus is now naturalizing in the Outer Western Carpathians subdivision of the Carpathian Mountains in Czech Republic and southern Poland.
It has spread from specimens planted as ornamental trees. Like most members of the white pine group, Pinus subgenus Strobus, the leaves are in fascicles of 5, or 3 or 4, with a deciduous sheath, they are flexible, bluish-green, finely serrated, 5–13 cm long, persist for 18 months, i.e. from the spring of one season until autumn of the next, when they abscise. The seed cones are slender, 8–16 cm long and 4–5 cm broad when open, have scales with a rounded apex and reflexed tip; the seeds are 4–5 mm long, with a slender 15–20 mm wing, are dispersed by wind. Cone production peaks every 3 to 5 years; the branches are spaced about every 18 inches on the trunk with 5-6 branches appearing like spokes on a wagon wheel. While eastern white pine is self-fertile, seeds produced this way tend to result in weak and malformed seedlings. Mature trees are 200–250 years old, some live to over 400 years. A tree growing near Syracuse, New York was dated to 458 years old in the late 1980s and trees in Michigan and Wisconsin were dated to 500 years old.
The eastern white pine has the distinction of being the tallest tree in eastern North America. In natural pre-colonial stands it is reported to have grown as tall as 70 m. There is no means of documenting the height of trees from these times, but eastern white pine may have reached this height on rare occasions. Greater heights have been reported in popular, but unverifiable, accounts such as Robert Pike's "Tall Trees, Tough Men". Total trunk volumes of the largest specimens are 28 m3, with some past giants reaching 37 or 40 m3. Photographic analysis of giants suggests volumes closer to 34 m3. Pinus strobus grows 1 m annually between the ages of 15 and 45 years, with slower height increments before and after that age range; the tallest presently living specimens are 50–57.55 m tall, as determined by the Native Tree Society. Three locations in southeastern United States and one site in northeastern United States have trees that are 55 m tall; the southern Appalachian Mountains have the most locations and the tallest trees in the present range of Pinus strobus.
One survivor is a specimen known as the "Boogerman Pine" in the Cataloochee Valley of Great Smoky Mountains National Park. At 57.55 m tall, it is the tallest measured tree in North America east of the Rocky Mountains. It has been measured by tape drop by the Native Tree Society. Before Hurricane Opal broke its top in October 1995, Boogerman Pine was 63 m tall, as determined by Will Blozan and Robert Leverett using ground-based measurements; the tallest specimens in Hartwick Pines State Park in Michigan are 45–48 m tall. In northeastern USA, 8 sites in 4 states have trees over 48 m tall, as confirmed by the Native Tre
Janka hardness test
The Janka hardness test measures the resistance of a sample of wood to denting and wear. It measures the force required to embed an 11.28 millimetres diameter steel ball halfway into a sample of wood. A common use of Janka hardness ratings is to determine whether a species is suitable for use as flooring; the hardness of wood varies with the direction of the wood grain. Testing on the surface of a plank, perpendicular to the grain, is said to be of "side hardness". Testing the cut surface of a stump is called a test of "end hardness". Side hardness may be further divided into "radial hardness" and "tangential hardness", although the differences are minor and neglected; the results are stated in various ways, which can lead to confusion when the actual units employed are not attached. Overall, the resulting measure is always one of force. In the United States, the measurement is in pounds-force. In Sweden it is in kilograms-force, in Australia, either in newtons or kilonewtons; this confusion is greatest when the results are treated as units, for example "660 Janka".
The Janka hardness test results tabulated below were done in accordance with ASTM D 1037-12 testing methods. Lumber stocks tested range from 1" to 2" thick; the tabulated Janka hardness numbers are an average. There is a standard deviation associated with each species. No testing was done on actual flooring. Other factors affect how flooring performs: the type of core for engineered flooring such as pine, HDF, oak, birch; the chart is not to be considered an absolute. Janka Hardness Scale For Wood - Side Hardness Chart of Some Woods USDA - Wood Handbook - Wood as an Engineering Material USDA - Janka Hardness Using Nonstandard Specimens
Bow and arrow
The bow and arrow is a ranged weapon system consisting of an elastic launching device and long-shafted projectiles. Archery is the practice, or skill of using bows to shoot arrows. A person who shoots arrows with a bow is called an archer. Someone who makes bows is known as a bowyer, one who makes arrows is a fletcher, one who manufactures metal arrowheads is an arrowsmith; the use of bows and arrows by humans for hunting predates recorded history and was common to many prehistoric cultures. They were important weapons of war from ancient history until the early modern period, where they were rendered obsolete by the development of the more powerful and accurate firearms, were dropped from warfare. Today and arrows are used for hunting and sports. A bow consists of a semi-rigid but elastic arc with a high-tensile bowstring joining the ends of the two limbs of the bow. An arrow is a projectile with a pointed tip and a long shaft with stabilizer fins towards the back, with a narrow notch at the end to contact the bowstring.
To load an arrow for shooting, the archer places an arrow across the middle of the bow with the bowstring in the arrow's nock. To shoot, the archer pulls back the arrow and the bowstring, which in turn flexes the bow limbs, storing elastic energy. While maintaining the draw, the archer sights along the arrow to aim it; the archer releases the arrow, allowing the limbs' stored potential energy to convert into kinetic energy, transmitted via the bowstring to the arrow, propelling it to fly forward with high velocity. A container or bag for additional arrows for quick reloading is called a quiver; when not in use, bows are kept unstrung, meaning one or both ends of the bowstring are detached from the bow. This removes all residual tension on the bow, can help prevent it from losing strength or elasticity over time. For many bow designs, this lets it straighten out more reducing the space needed to store the bow. Returning the bowstring to its ready-to-use position is called stringing the bow; the bow and arrow appears around the transition from the Upper Paleolithic to the Mesolithic.
After the end of the last glacial period, use of the bow seems to have spread to every inhabited region, except for Australasia and most of Oceania. The earliest definite remains of bow and arrow are from Europe. Possible fragments from Germany were found at Mannheim-Vogelstang dated 17,500-18,000 years ago, at Stellmoor dated 11,000 years ago. Azilian points found in Grotte du Bichon, alongside the remains of both a bear and a hunter, with flint fragments found in the bear's third vertebra, suggest the use of arrows at 13,500 years ago. At the site of Nataruk in Turkana County, obsidian bladelets found embedded in a skull and within the thoracic cavity of another skeleton, suggest the use of stone-tipped arrows as weapons about 10,000 years ago. Microliths discovered on the south coast of Africa suggest that projectile weapons of some sort may be at least 71,000 years old; the oldest extant bows in one piece are the elm Holmegaard bows from Denmark which were dated to 9,000 BCE. Several bows from Holmegaard, date 8,000 years ago.
High-performance wooden bows are made following the Holmegaard design. The Stellmoor bow fragments from northern Germany were dated to about 8,000 BCE, but they were destroyed in Hamburg during the Second World War, before carbon 14 dating was available; the bow was an important weapon for both hunting and warfare from prehistoric times until the widespread use of gunpowder in the 16th century. Organised warfare with bows ended in the mid 17th century in Europe, but it persisted into the early 19th century in Eastern cultures and in hunting and tribal warfare in the New World. In the Canadian Arctic bows were made until the end of the 20th century for hunting caribou, for instance at Igloolik; the bow has more been used as a weapon of tribal warfare in some parts of Sub-Saharan Africa. The British upper class led a revival of archery from the late 18th century. Sir Ashton Lever, an antiquarian and collector, formed the Toxophilite Society in London in 1781, under the patronage of George Prince of Wales.
The basic elements of a bow are a pair of curved elastic limbs, traditionally made from wood, joined by a riser. Both ends of the limbs are connected by a string known as the bow string. By pulling the string backwards the archer exerts compressive force on the string-facing section, or belly, of the limbs as well as placing the outer section, or back, under tension. While the string is held, this stores the energy released in putting the arrow to flight; the force required to hold the string stationary at full draw is used to express the power of a bow, is known as its draw weight, or weight. Other things being equal, a higher draw weight means a more powerful bow, able to project heavier arrows at the same velocity or the same arrow at a greater velocity; the various parts of the bow can be subdivided into further sections. The topmost limb is known as the upper limb. At the tip of each limb is a nock, used to attach the bowstring to the limbs; the riser is divided into the grip, held by the archer, as well as the arrow rest and the bow window.
The arrow rest is a small ledge or extension above the grip which the arrow rests upon while being aimed. The bow window is that part of the
A plant cutting is a piece of a plant, used in horticulture for vegetative propagation. A piece of the stem or root of the source plant is placed in a suitable medium such as moist soil. If the conditions are suitable, the plant piece will begin to grow as a new plant independent of the parent, a process known as striking. A stem cutting produces new roots, a root cutting produces new stems; some plants can be grown from leaf pieces, called leaf cuttings, which produce both stems and roots. The scions used in grafting are called cuttings. Propagating plants from cuttings is an ancient form of cloning. There are several advantages of cuttings that the produced offspring are clones of their parent plants. If a plant has favorable traits, it can continue to pass down its advantageous genetic information to its offspring; this is economically advantageous as it allows commercial growers to clone a certain plant to ensure consistency throughout their crops. The poet Theodore Roethke wrote about plant cuttings and root growth behavior in his poems "Cuttings" and "Cuttings" found in his book The Lost Son: And Other Poems.
Cuttings are used as a method of asexual reproduction in succulent horticulture referred to as vegetative reproduction. A cutting can be referred to as a propagule. Succulents have evolved with the ability to use adventitious root formation in reproduction to increase fitness in stressful environments. Succulents grow in shallow soils, rocky soils, desert soils. Seedlings from sexual reproduction have a low survival rate. Cuttings have both water and carbon stored and available, which are resources needed for plant establishment; the detached part of the plant remains physiologically active, allowing mitotic activity and new root structures to form for water and nutrient uptake. Asexual reproduction of plants is evolutionarily advantageous as it allows plantlets to be better suited to their environment though retention of epigenetic memory, heritable patterns of phenotypic differences that are not due to changes in DNA but rather histone modification and DNA methylation. Epigenetic memory is heritable through mitosis, thus advantageous stress response priming is retained in plantlets from excised stem.
Adventitious root formation refers to roots that form from any structure of a plant, not a root. Adventitious root formation from the excised stem cutting is a wound response. At a molecular level when a cutting is first excised at the stem there is an immediate increase in jasmonic acid, known to be necessary for adventitious root formation; when the cutting is excised from the original root system the root inhibiting hormones and strigolactone, which are made in the root and transported to the stem, decrease in concentration. Polyphenol degradation decreases; the increased auxin concentration increases nitric oxide concentration which initiates root formation through a MAPK signal cascade and a cGMP-dependent pathway that that both regulate mitotic division and are both necessary for the initiation of adventitious root formation. The root primordia form from cambial cells in the stem. In propagation of detached succulent leaves and leaf cuttings, the root primordia emerges from the basal callous tissue after the leaf primordia emerges.
It was known as early as 1935 that when indolyl-3-acetic acid known as auxin, is applied to the stem of root cuttings, there is an increase the average number of adventitious roots compared to cuttings that are not treated. Researchers applied this compound to stems without leaves that would not have any root formation and found that auxin induced root formation, thus determining auxin is necessary for root formation. Identification of this hormone has been important to industries that rely on vegetative propagation, as it is sometimes applied to fresh cuttings to stimulate root growth; some plants form roots much more than others. Stem cuttings from woody plants are treated differently, depending on the maturity of the wood: Softwood cuttings come from stems that are expanding, with young leaves. In many species, such cuttings form roots easily. Semi-hardwood cuttings come from have mature leaves. Hardwood cuttings come from matured stems, are propagated while dormant. Most plant cuttings are stem pieces, have no root system of their own, they are to die from dehydration if the proper conditions are not met.
They require a moist medium, however, cannot be too wet lest the cutting rot. A number of media are used in this process, including but not limited to soil, vermiculite, rock wool, expanded clay pellets, water given the right conditions. Most succulent cuttings can be left in open air until the cut surface dries, which may improve root formation when the cutting is planted. In temperate countries, stem cuttings may be taken of soft wood and hard wood which has specific differences in practice. Certain conditions lead to more favorable outcomes for cuttings. Stem cuttings of young wood should be taken in spring from the upper branches, while cuttings of hardened wood should be taken in winter from the lower branches. Common bounds on the length of stem cuttings are between 5–15 centimetres for soft wood and between 20–25 centimetres for hard wood. Soft wood cuttings do best when about two thirds of the fol