Search results
Results from the WOW.Com Content Network
Von Pechmann was born in Nürnberg, the only son of a doctor, who was also named Hans.The von Pechmanns had distinguished themselves as soldiers; in 1702, von Pechmann's ancestor Martin Günther von Pechmann, a general of artillery in the Bavarian army, had been raised to the rank of a baron of the Holy Roman Empire by Leopold I. [6]
Polyethylene was first synthesized by the German chemist Hans von Pechmann, who prepared it by accident in 1898 while investigating diazomethane. [12] [a] [13] [b] When his colleagues Eugen Bamberger and Friedrich Tschirner characterized the white, waxy substance that he had created, they recognized that it contained long −CH 2 − chains and termed it polymethylene.
1898: Synthesis of polyethylene, the most common plastic, by Hans von Pechmann [159] 1898: First synthesis of purine by Emil Fischer. He had also coined the word in 1884. [160] Early 20th century: Schlenk flask by Wilhelm Schlenk [161] 1900s: Haber process by Carl Bosch and Fritz Haber [133] 1902: Ostwald process by Wilhelm Ostwald [162]
On October 5, 2017, the National Environmental Health Association sponsored a webinar about the hazards involved for workers and residents associated with cured-in-place pipe repair. The video can be found here. [22] Several questions [23] about the webinar, and the study have been raised, and feedback noted by industry members.
Two German chemists also preceded Schlotterbeck in discovery of the reaction, Hans von Pechmann in 1895 and Viktor Meyer in 1905. [4] [5] The reaction has since been extended to the synthesis of β-keto esters from the condensation between aldehydes and diazo esters. [6] The general reaction scheme is as follows: General Scheme for Buchner Reaction
Reinforced thermoplastic pipe (RTP) is a type of pipe reinforced using a high strength synthetic fibre such as glass, aramid or carbon. It was initially developed in the early 1990s by Wavin Repox, Akzo Nobel and by Tubes d'Aquitaine from France, who developed the first pipes reinforced with synthetic fibre to replace medium pressure steel pipes in response to growing demand for non-corrosive ...
Diazomethane is an organic chemical compound with the formula CH 2 N 2, discovered by German chemist Hans von Pechmann in 1894. It is the simplest diazo compound.In the pure form at room temperature, it is an extremely sensitive explosive yellow gas; thus, it is almost universally used as a solution in diethyl ether.
HDPE pipe is a type of flexible plastic pipe used to transfer fluids and gases. It is often employed for replacing aging concrete or steel main pipelines . Constructed from the thermoplastic HDPE (high-density polyethylene ), it has low permeability and robust molecular bonding, making it suitable for high-pressure pipelines .