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Thermal and miscible methods are commonly used for in situ recovery of heavy oil and bitumen. Both techniques have their own limitations and benefits. However, these methods can be combined by co-injecting solvent with steam or injecting solvent into a pre-heated reservoir. The current work was undertaken to study the performance of solvents at higher temperatures for heavy oil/bitumen recovery. Glass bead packs and Berea sandstone cores were used in the experiments to represent different types of pore structures, porosity and permeability. After saturating with heavy oil, the samples were exposed to the vapor of paraffinic solvents (propane and butane) at a temperature above the boiling point of the solvent, and a constant pressure of 1500 kPa. A mechanical convection oven was used to maintain constant temperature across the setup. The setup was designed in such a way that a reasonably long sample (up to 30 cm) can be tested to analyze the gravity effect. The oil recovered from each of these experiments was collected using a specifically designed collection system and analyzed for composition, viscosity and asphaltene content. The final amount of oil recovered in each case (recovery factor but not extraction rate) was also analyzed and the quantity and nature of asphaltene precipitated with each of the tested solvents under the prevailing temperature and pressure of the experiment was reported. Optimal conditions for each solvent type were identified for the highest ultimate recovery. It was observed that recovery decreased with increasing temperature and pressure of the system for both solvents, and that the best results were found when experimental temperature is only slightly higher than the saturation temperature of the solvent used. It was also noticed that butane diluted the oil more than propane which resulted in lower asphaltene content and viscosity of oil produced with butane as a solvent.

As a result of the October Revolution, the ideas and activities that had been confined to an artistic, intellectual, or aristocratic minority, became overnight the property of the masses. In September 1918, the musicologist and educationalist Nadezhda Bryusova spelt out the role of music in the new society 'Music should give a capacity to live and a capacity to build life'.1 Led by the musical departments of Narkompros (the Ministry of Education and Culture) and Proletkul't (the proletarian cultural-education organizations), concerted efforts were made to break down the barriers between professional musicians, composers, and the general public. Attempts were also made to raise the standards of musical knowledge amongst the new audience. However, it soon became apparent that there was a need for a new breed of composer who was in tune with the desires and aspirations of the new society. A group of politically-minded composers which soon fell into this category was formed at the Moscow Conservatory in January 1925 as a result of a competition to compose a work commemorating the first anniversary of Lenin's death. That group was known as Prokoll, an abbreviation of Proizvodstvennii kollektiv (Production Collective). The specific aims of Prokoll were firstly 'to search for new musical forms consonant with the times and based on the achievements of past and present musical culture', and secondly 'to create new mass musical forms (marches, mass songs, placards, and others) designed for mass performance'.2 The founding members of the group included Aleksandr Davidenko, Genrikh Bruk, Boris Shekhter, Viktor Belyy, Sergey Ryauzov, Marian Koval', Nikolay Chemberdzhi, and Zara Levina. By the time the group had disbanded in April 1932, several of its founding members had joined the like-minded Russian Association of Proletarian Musicians (RAPM). But they were