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Vicat softening temperature or Vicat hardness is the determination of the softening point for materials that have no definite melting point, such as plastics. It is taken as the temperature at which the specimen is penetrated to a depth of 1 mm by a flat-ended needle with a 1 mm 2 circular or square cross-section.
A Soxhlet extractor is a piece of laboratory apparatus [1] invented in 1879 by Franz von Soxhlet. [2] It was originally designed for the extraction of a lipid from a solid material. Typically, Soxhlet extraction is used when the desired compound has a limited solubility in a solvent, and the impurity is insoluble in that solvent. It allows for ...
The softening point is the temperature at which a material softens beyond some arbitrary softness. [1] It can be determined, for example, by the Vicat method (ASTM-D1525 or ISO 306), Heat Deflection Test (ASTM-D648) or a ring and ball method (ISO 4625 or ASTM E28-67/E28-99 or ASTM D36 or ASTM D6493 - 11 or JIS K 6863).
Most mature plant cells contain one large central vacuole encompassed by a membrane called the tonoplast. Vacuoles of plant cells act as storage compartments for the nutrients and waste of a cell. The solution that these molecules are stored in is called the cell sap. Pigments that color the cell are sometime located in the cell sap.
World locations of Vicat. The company was established in 1853 by Joseph Vicat (1821–1902), son of Louis Vicat, who invented artificial cement in 1817. His cement plant was at Genevrey-de-Vif south of Grenoble . It used an argillaceous limestone that Joseph Vicat had established as suitable by chemical analysis. The company expanded in 1922 ...
In plants, carotenoids can occur in roots, stems, leaves, flowers, and fruits. Carotenoids have two important functions in plants. First, they can contribute to photosynthesis. They do this by transferring some of the light energy they absorb to chlorophylls, which then uses this energy for photosynthesis. Second, they can protect plants which ...
The basic function of the xylem is to transport water upward from the roots to parts of the plants such as stems and leaves, but it also transports nutrients. [ 1 ] [ 2 ] The word xylem is derived from the Ancient Greek word, ξύλον ( xylon ), meaning " wood "; the best-known xylem tissue is wood, though it is found throughout a plant. [ 3 ]
Expansins characteristically cause wall stress relaxation and irreversible wall extension (). [15] This process is essential for cell enlargement. Expansins are also expressed in ripening fruit where they function in fruit softening, [16] and in grass pollen, [7] where they loosen stigmatic cell walls and aid pollen tube penetration of the stigmain germinating seeds for cell wall disassembly ...