Vycor

-

Vycor - laboratory glass with high temperature resistance and thermal shock (cracks due to sudden temperature changes). It was first produced by Corning Incorporated. Vycor is made up of 96% silicon dioxide, but unlike fused silica, it can be molded in various shapes. Production methods

Vycoru products are manufactured in several stages. First, the relatively soft alkali-borosilicate glass is melted and molded with typical techniques of making glass in a certain shape. It is exposed to high temperatures, which causes the glass to form two phases of glass with a certain composition. The first one is rich in alkali and borates, and can easily be dissolved in acid. The second phase is practically quartz and is insoluble. Then the glass is immersed in a hot acidic solution which removes the soluble phase and leaves the quartz glass phase. At this stage the glass is porous. Ultimately, the glass object is heated to a temperature higher than 1200 ° C in which the porous glass structure is poured, resulting in the new object slightly shrinking and pore-free. The final product of this technique is reconstructed glass.

Sometimes the last step is skipped; porous glass remains. Such glass has good affinity for water and is ideal for condensing water from steam. It is widely used in science and engineering.

The immersion of porous glass in certain chemicals before the final stage of its heating causes the color of this material to increase and its resistance to high temperatures.

wiki

Comments

Post a Comment

Popular posts from this blog

Association of Jewish handicrafts "Jad Charuzim"

-
The Jewish Handgun Association "Jad Charuzim" - a Jewish craft organization, operating in Galicia since 1875. She was the founder of many synagogues (eg Yad Charuzim Synagogue in Sanok, Jad Charuzim Synagogue in Yaroslav, Zasany Synagogue in Przemysl), burs, self-help and charity activities, libraries, readings and readings. In 1927, in order to enable its members to use small loans, the association established its own credit cooperative "Cooperative Bank of Cooperatives". The Association's activities ceased during World War II. wiki
Read more

Grouping Red Arrows

-
Raggruppamento Frecce Rosse (Red Arrow Group) - Collaborative armed formation of an Italian army composed of Indians, Arabs and Africans during the Second World War. From May to July 1942, an armed formation was formed under the name Raggruppamento Centri Militari, consisting mainly of British Army prisoners of war originating in Arab countries, India and northern and eastern Africa. They were Hindus, Arabs, Sudanese, Tunisians. The officers and the non-commissioned officers were Italian. The formation consisted of three subdivisions: It was about 1.2 thousand. including about 400 Hindus and about 200 Arabs. Colonel Massimo Invrea de Stato headed it. Subsequently, a small number of Tunisians and Indians were sent to Italy to complete their parachute training in Tarquinia. In August 1942, the formation was renamed Raggruppamento Frecce Rosse. After the defeat of the German-Italian forces at El Alamein at the turn of October and November 1942, the Indians and Arabs lost motivation t...
Read more

Catechism of Polish Child

-
Catechism of the Polish Child - one of the patriotic poets Wladyslaw Belzy published in the volume of the Polish Children's Catechism in 1900. The poem is also known under the title "Confession of the Polish Child" or "Catechism of a Young Pole". It starts with the words "Who are you? "Little Pole". His simple form, referring to children's calculations, made him the simplest form of patriotic education of the youngest generation. The work consists of basic questions and answers about the identity features of a young Pole. It made it easier to memorize national characters and symbols. This work was covered in 1951 by censorship in Poland, subject to immediate withdrawal from libraries. wiki
Read more