Wood is a structural tissue found in the stems and roots of trees and other woody plants. It is an organic material - a natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin that resists compression. Wood is sometimes defined as only the secondary xylem in the stems of trees, or it is defined more broadly to include the same type of tissue elsewhere such as in the roots of trees or shrubs. In a living tree it performs a support function, enabling woody plants to grow large or to stand up by themselves. It also conveys water and nutrients between the leaves, other growing tissues, and the roots. Wood may also refer to other plant materials with comparable properties, and to material engineered from wood, or woodchips or fiber.
Wood has been used for thousands of years for fuel, as a construction material, for making tools and weapons, furniture and paper. More recently it emerged as a feedstock for the production of purified cellulose and its derivatives, such as cellophane and cellulose acetate.
As of 2020, the growing stock of forests worldwide was about 557 billion cubic meters. As an abundant, carbon-neutral renewable resource, woody materials have been of intense interest as a source of renewable energy. In 2008, approximately 3.97 billion cubic meters of wood were harvested. Dominant uses were for furniture and building construction.
A 2011 discovery in the Canadian province of New Brunswick yielded the earliest known plants to have grown wood, approximately 395 to 400 million years ago.
Wood can be dated by carbon dating and in some species by dendrochronology to determine when a wooden object was created.
People have used wood for thousands of years for many purposes, including as a fuel or as a construction material for making houses, tools, weapons, furniture, packaging, artworks, and paper. Known constructions using wood date back ten thousand years. Buildings like the European Neolithic long house were made primarily of wood.
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This course critically interrogates the connection of modern architecture with its hypothetical origins by setting it alongside new accounts of the dawn of humanity.
Ce cours permet de maitriser les aspects fondamentaux et pratiques du dimensionnement des structures en bois. Il traite des poutres, des poteaux, des assemblages, des systèmes porteurs et des problème
The presentation of tree growth and formation of wood anatomical structures, linked to the description of specific physical and mechanical properties, makes it possible to understand the different for
In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are usable as lumber or plants above a specified height. In wider definitions, the taller palms, tree ferns, bananas, and bamboos are also trees. Trees are not a monophyletic taxonomic group but consist of a wide variety of plant species that have independently evolved a trunk and branches as a way to tower above other plants to compete for sunlight.
Woodworking is the skill of making items from wood, and includes cabinetry, furniture making, wood carving, joinery, carpentry, and woodturning. Along with stone, clay and animal parts, wood was one of the first materials worked by early humans. Microwear analysis of the Mousterian stone tools used by the Neanderthals show that many were used to work wood. The development of civilization was closely tied to the development of increasingly greater degrees of skill in working these materials.
A pencil (ˈpɛnsəl) is a writing or drawing implement with a solid pigment core in a protective casing that reduces the risk of core breakage, and keeps it from marking the user's hand. Pencils create marks by physical abrasion, leaving a trail of solid core material that adheres to a sheet of paper or other surface. They are distinct from pens, which dispense liquid or gel ink onto the marked surface. Most pencil cores are made of graphite powder mixed with a clay binder.
Explores wood gasification principles, processes, and applications, emphasizing anaerobic digestion and biogas production as sustainable energy solutions.
A trans-disciplinary approach in structural design and digital architecture of timber structures with advanced manufacturing workflow.
In recent years, xylem sap composition has been shown to affect xylem hydraulics. However, information on how much xylem sap composition can vary across seasons and specifically under drought stress is still limited. We measured xylem sap chemical composit ...
Oxford2023
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Our ability to study and valorize the lignin fraction of biomass is hampered by the fundamental and still unmet challenge of precisely quantifying native lignin's structural features. Here, we developed a rapid elevated-temperature H-1-C-13 Heteronuclear S ...
Wiley-V C H Verlag Gmbh2024
There are several methods to isolate near-native lignins, including milled-wood lignin, enzymatic lignin, cellulolytic enzyme lignin, and enzymatic mild-acidolysis lignin. Which one is the most representative of the native lignin? Herein, near-native ligni ...