A facile method is proposed to use a computer controlled Arc discharge gap between graphite electrodes together with an yttrianickel catalyst to synthesize carbon nanotubes under an Ar-H 2 gases mixture atmosphere by applying different DC currents and pressure. This produces carbon nanotubes with decreased diameters and increased length. XRD evidence indicated a shift toward higher crystallinity nanotubes. Yields of the CNTs after purification were also enhanced.
Estimates of the conventional proven hydrocarbon reserves show a tendency toward depletion, and in the near future they will be insufficient to meet the ever-growing global energy demand. The problem of crude oil deficiency can be solved by involving unconventional hydrocarbon resources in both recovery and refinery. However, the hydrogen deficiency of heavy oil and natural bitumen requires technical and technological solutions. Therefore, the hydrogen-donating capacity of water and solvents, particularly in reservoir conditions, is very attractive. In this paper, we study the hydrogen-donating capacity of naphthenic and polar solvents during hydrothermal treatment of heavy oil from Ashal’cha reservoir (Republic of Tatarstan, Russia). It was established that naphthenic solvents significantly influence the viscosity reduction due to the destructive hydrogenation of resins and asphaltenes. Among naphthenic solvents, decalin significantly increases the amount of evolved gases, particularly C4–C10 isomers and aromatics. However, the maximum evolved gases among all of the used solvents correspond to formic acid. The results of elemental analysis revealed that the H/C ratio rises in crude oil samples after hydrothermal treatment in the presence of cyclohexane and decalin. FT-IR spectral indices revealed an increase in crude oil aliphaticity in case of using solvents from the cyclohexane–tetralin–decalin series due to the cleavage of carbon–heteroatom bonds in aliphatic substitutes of resins and asphaltenes. Significant changes in the FT-IR spectra of crude oil are observed in the presence of tetralin.
The corrosion rates of cast iron and copper in drinkable water distribution systems are compared in this investigation. Sixty-one solutions were prepared, of varying concentrations in Cl-, NO-3, SO=4, and with differences in alkalinity, pH, and Langelier index. Cut from actual pipe, 2070 specimens 4 cm by 3 cm by 0.1 cm (1035 cast iron and 1035 copper) were immersed in the solutions for 3, 6, 9, 12, or 15 days, and their corrosion was determined by weight loss. For both metals, corrosion was more rapid during the first three days. The cast iron corrosion product contained between 35% and 55% iron. X-ray diffraction revealed the presence of goethite, lepidocracite, and after three days of immersion, amorphous magnetite. For the same experimental conditions, the copper corrosion rate was significantly smaller than that of ductile cast iron. The corrosion rate of copper was not found to be affected by the composition of the water. In this investigation, no correlation was found between the Langelier index and the corrosion rate for copper or cast iron. This was true for both negative and positive Langelier index.
Conventional quenching versus ZnO-NP emulsion and heat treatments for medium carbon steel (CK45) has been carried out in laboratory environment condition. For comparison, the mechanical properties of CK45 and microstructure were examined. The main parameter focused in this work was the concentration of ZnO-NP in deionized water. Thus, emulsion represents a quenching medium for CK45 specimens. Optical microscope analysis for CK45 microstructure, hardness and tensile test for all specimens were done to evaluate the role of nano ZnO additives as quenching media at different concentration. Experimental results reveal that the addition of nanoparticles to the base fluid (water) astonishingly enhanced some mechanical properties as tensile strength and yield stress. 2wt.% of ZnO-NP raised the yield 14.8% and the UTS by 16.9%.
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