موضوع عن الخشب بالانجليزي

بحوث بالانجليزي عن الاخشاب و انواعها.

معنى خشب بالإنجليزي

موضوع انجليزي للصف الثامن اللـغة الانجـليـزيـة

 موضوع انجليزيعـن الخشب  5 أسطر وكلمات سهله

 تعبير انجليزي خشب

برجراف عن wood

ما معنى كلمة خشب بالانجليزي

اسماء الخشب بالانجليزية

موضوع عن الخشب بالانجليزي

paragraph about wood

معنى كلمة wooden

اسماء بعض الاخشاب باللغة الانجليزية.

موضوع عن الخشب بالانجليزي

paragraph about wood

اسماء الخشب بالانجليزية

انواع الاخشاب الصناعية

انواع الخشب

ما معنى كلمة خشب بالانجليزي

انواع الاخشاب

معنى كلمة wooden

خشب البلوط

paragraph about wood

properties of wood

wood material

wood types

wood definition

physical properties of wood

برجراف عن wood

ما معنى كلمة woods

اسماء الخشب الصناعي

paragraph about wood

اسماء الخشب باللغة العربية

اسماء الخشب بالانجليزية

beech pine wood

اسماء الخشب باللغة العربية

خشب سويدي بالانجليزي

اسماء الخشب الصناعي

خشب السنديان بالانجليزي

قطعة خشب بالانجليزي

خشب السويد بالانجليزية

خشب الموسكى

Wood is a plant tissue. It constitutes the largest part of the trunk of woody plants. The wood provides the role of conduction of the raw sap from the root to the leaf and the role of mechanical support of the plant. It also sometimes serves as a reserve fabric.

The standard NF B 50-003 (defining the nomenclature of wood) defines it as "a set of secondary resistant tissues (support, conduction, and storage) which form the trunks, branches and roots of woody plants. Resulting from the functioning of the peripheral cambium, it is located between this one and the marrow.

It is one of the most appreciated materials for its mechanical properties, for its calorific value and as raw material for multiple branches of industry. It has many uses in the building and industry (paper industries, chemical industries ...), and as fuel. Some plants (palm, bamboo ...) produce lignified tissues but not from a secondary cambium: it is not wood.

The discipline that studies wood is xylology, a collection of wood samples is called a xylotheque.

There are two types of wood, composed of different types of plant tissues:

Homoxylated wood

It is found in gymnosperms ("softwoods").

• Tracheid fibers with both support and conduction roles;

• Rays: tracheid fibers and horizontal parenchyma);

• Vertical parenchyma.

Heteroxylated wood

It is found in angiosperms (flowering plants). The support and conduction functions are performed by different cells:

• Tracheid fibers): Resistant, axially arranged bundles of cells that provide stiffness and mechanical strength. It is a bio composite consisting of cellulose, hemicellulose and lignin.

• Vessels: formed of elements of vessels, hollow cells that serve to drive the raw sap from the roots to the leaves.

• Vertical parenchyma: Parenchymal cells contribute to the transport of nutrients. These parenchyma, associated with the vessels, give particular patterns to each species (especially tropical species) on the cross section (perpendicular to the axis of the trunk).

• Woody (or medullary) rays: horizontal parenchyma, consisting of thickened and lignified walled reserve cells, which accompany the vascular tissue. These cells also participate in the support function. Their orientation is transverse and radiant starting from the longitudinal axis of the tree. The photo on the right shows some woody rays that start from the center of the trunk.

The arrangement of the tissues, the shape and size of the cells, is called the woody plan or radius. This one is characteristic of each essence. For example, it gives what is called "mesh", which is the aspect of the radial section of wood (longitudinal section in the direction of the radius of the tree, the woody rays being observable in the form of bands, sometimes decorative). This mesh is characteristic in oak, beech, plane tree, niangon and mahogany. The cells and fibers are oriented in the axial direction, which determines the "wood grain".

Lumber is the one used for the construction of house structures and the manufacture of a multitude of other products, often related to residential construction and renovation.

• Raw wood in the form of posts and logs, after sawing.

Sawn from logs:

• Structural wood: frames, wooden house (stacked wood, timber frame house or beam studs) and cladding, terraces, railway sleepers. These woods can be rough sawn or planed. This is usually a choice framework (choice 2 or ST II in France). Wood frame houses account for 8% of the new construction market per year. The progression is very fast with annual growth rates of 20 to 25% 20. The wood regulates the humidity and temperature inside. It is an excellent acoustic insulation. In case of fire, the wood transmits heat 10 times slower than concrete and 250 times slower than steel.

• marine wood: ribs, planks, spars (mast, boom ...), keel piece

• aeronautical woods: structures of the first planes. Plywood is an invention of aeronautics. Today rather used for small planes of tourism in amateur or industrial construction

• Raw sawn timber, domestic wood: concrete formwork, scaffolding, pallets, packaging ...

• planed wood: paneling (wall frieze), flooring, carpentry, wink, terrace board, ...

• veneers: Unwound or sliced wood. Fine woodwork species ...

• Engineered wood, secondary wood: glulam, reconstituted, butted, plywood, laminated, "I" beam ...

• Shooting wood: balls, pins, tool handles, toys ...

• Slicing wood: plywood ...

• Split wood: staves for cooperage, tavaillons (roofing shingles) ...

• Arched wood: "Thonet" chairs

• Structural elements: Glue-laminated timber, engineered wood, butted timber I-beams.

• Panels: Particleboard (OSB), Particleboard or chipboard, Medium Density (MDF) or High Density (HDF) panels

• Other uses: supervision; woodwork; violin ; matches ...

Artisanal uses

• Wood is a means of artistic expression in marquetry and wood carving,

• It is a traditional medium for painting with oil or tempera on wood panel. Since ancient Egypt the wood is covered with polished gesso before being painted.

• In the kitchen, some parts of trees are consumed in various countries (bamboo shoots, palm heart, etc.)