Search results
Results from the WOW.Com Content Network
The mortar and pestle, with the Rod of Asclepius, the Green Cross, and others, is one of the most pervasive symbols of pharmacology. [10] For pharmaceutical use, the mortar and the head of the pestle are usually made of porcelain, while the handle of the pestle is made of wood. This is known as a Wedgwood mortar and pestle and originated in 1759.
Those who wish to adopt the textbooks are required to send a request to NCERT, upon which soft copies of the books are received. The material is press-ready and may be printed by paying a 5% royalty, and by acknowledging NCERT. [11] The textbooks are in color-print and are among the least expensive books in Indian book stores. [11]
A cement is a binder, a chemical substance used for construction that sets, hardens, and adheres to other materials to bind them together. Cement is seldom used on its own, but rather to bind sand and gravel together. Cement mixed with fine aggregate produces mortar for masonry, or with sand and gravel, produces concrete. Concrete is the most ...
Description: This book was intended as an introduction to new theories in chemistry and as such, was one of the first Chemistry textbooks. [9] Importance: Introduction, Influence. Aside from being one of the first chemistry textbooks, the book was one of the first to state the Law of conservation of mass, define a chemical element, and contain ...
Hydraulic lime concretes have been in use since Roman times, either as mass foundation concretes or as lightweight concretes using tufa or pumice as aggregates and a wide range of pozzolans to achieve different strengths and speeds of set. This meant that lime could be used in a wide variety of applications including floors and even vaults or ...
Sorel cement (also known as magnesia cement or magnesium oxychloride) is a non-hydraulic cement first produced by the French chemist Stanislas Sorel in 1867. [1]In fact, in 1855, before working with magnesium compounds, Stanislas Sorel first developed a two-component cement by mixing zinc oxide powder with a solution of zinc chloride.
Lime mortar or torching [1] [2] is a masonry mortar composed of lime and an aggregate such as sand, mixed with water. It is one of the oldest known types of mortar, used in ancient Rome and Greece, when it largely replaced the clay and gypsum mortars common to ancient Egyptian construction. [3]
The excavation of the underground aqueduct of Megara revealed that a reservoir was coated with a pozzolanic mortar 12 mm thick. This aqueduct dates back to c. 500 BC. [9] Pozzolanic mortar is a lime based mortar, but is made with an additive of volcanic ash that allows it to be hardened underwater; thus it is known as hydraulic cement.