Carbon conductivity phenomena

GP 2[ [R 3a[ Catalysts need to be initially activated on-stream with a mixture of 20% ethylene and 20% oxygen in methane as balance [44], The temperature was raised until first formation of carbon dioxide became notable. The initial selectivity is close to 70% and after time-in-stream for 1 day at 250 °C decreases to 62% at 1.3% conversion. This loss in selectivity at the expense of conversion is a general phenomenon during all investigations conducted in [44], Non-promo ted catalysts show a certain decrease in selectivity within a few days, particularly at high temperature and conversion. 

This phenomenon leads to decrease of conductivity of the electrolyte and reactivity of methanol and results in the necessity of periodical maintenance of the electrolyte. In add media, in contrast, carbon dioxide is ejected and causes no maintenance problems. 

GO hydrogenolysis to PG in presence of a Ni/Re catalyst is favored by a solvent that possesses both a hydroxyl group and a bulky carbon backbone. We attribute this phenomenon to facilitated access of GO to the surface of the catalyst. We are conducting absorption experiments to elucidate in more detail the phenomena that take place at the surface of the catalyst. 

Of interest in this system is the generation of electronically conductive carbon in the cathode during discharge. This phenomenon leads to a reduction in cell impedance during operation. Conventional Li salts and organic solvents such as Li triflate (LiCF3S03) in PC/DME are often used as the electrolyte. 

The PTC phenomenon, in effect, provides the means of making a thermal switch, operated either by an external change in temperature or by an increase in current that generates heat internally, see Fig. 8.20. A common form of self-regulating heater is made by extruding a strip with the cross-section shown in Fig. 8.21, where the conductive component consists of polyethylene/carbon-black composite that is radiation-crosslinked after fabrication. The strip may be extruded in long lengths... 

The thermal conductivities of transition metal carbides increase with increasing temperature, an unexpected phenomenon that has been investigated extensively on titanium, zirconium, hafnium and carbides and carbonitrides. Previous studies have reported a linear increase of the thermal conductivity with temperature, but more recent investigations have revealed a nonlinear relationship. Carbon... 

Injection of 0.6 PV of carbon dioxide produced only 6% of a pore volume of additional oil. Linear laboratory miscible floods normally produce over 10% additional oil. The lower value of oil recovery reflects the inefficient macroscopic oil displacement induced by an unfavorable mobility ratio that exists between carbon dioxide and the oil. This phenomenon has not been reported for experiments conducted in long, slim tube models, where their smaller diameter, 0.2 in. vs. 1.6 in., masks the effect. 

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