temperature effect

Production of Bitumen Modified with Low-Molecular Organic Compounds from Petroleum Residues. 6. Temperature Effect on the Chemical Modification of Bitumen with Maleic Anhydride

The oxidized bitumen produced at the Ukrainian refinery was modified with maleic anhydride. The process temperature was proved to have the most significant effect on modification. The chemical interaction of maleic anhydride with the components of oxidized bitumen was confirmed. At low temperatures (up to 403 K) the chemistry of the modification process is another than chemistry of the process carried out at high temperatures. The structures of the modified bitumen were established at different process temperatures (403, 423 and 443 K) using FTIR spectroscopy.

OPTOELECTRONIC QUARTZ SENSOR OF FORCE AND PRESSURE

Sensors with a frequency output signal are marked as particularly high accuracy, it is easy to switch, and signals may be transmitted over long distances. The main element of such sensors is an electromechanical oscillator connected to the feedback of the autogenerator. String metal oscillators do not provide the required measurement accuracy due to unsatisfactory elasticity, hysteresis, relaxation, and drift of characterisrics. The creation of oscillators made of quartz and silicon due to the perfection of these materials, is difficult.