Error-tolerability enhancement via bit inversion and median filtering for single-bit errors in image processing circuits

Microsystem Technologies - Error-tolerance has been proposed as a new method to increase effective yield of a system. The basic idea is that faulty chips might be still acceptable as long as their...     

Pressure influences on CO2 reaction with cyclohexylamine using ionic liquid as reaction medium and catalyst

Inserting carbon dioxide (CO₂) into ammonia molecules to produce urea is a traditional CO₂ utilization method. An ionic liquid (IL), 1-butyl-3-methylimidazolium bromide ([Bmim]Br), was used as reaction medium and [Bmim]Br/KOH as catalyst. This study investigates CO₂ carbonylation of cyclohexylamine and its reaction performance in a number of low- and high-pressure CO₂/IL systems. The reaction yield was greatly increased as pressure ranges changed from 15–50 bar to 80–100 bar; the physiochemical properties of substrates and catalyst were greatly affected by CO₂ in supercritical state. The yield was improved from 69% at 30 bar to 91.6% at 100 bar, much better than a previous study result of 53.5%, but as pressures further increased, a significant decrease was observed. The reaction activation energy was calculated to be 3.942 and 4.354 kcal/mol in mild and supercritical conditions. This process shows a low threshold reaction energy and great potential for industrial applications to store CO₂ in amine molecular structures.