This research work aims to proceed with the optimization of Fused Deposition Modeling (FDM) printing parameters for acrylonitrile butadiene styrene (ABS) and polyamide (Nylon) to improve fatigue resistance. For that purpose, the methodology of the paper involves two main approaches: experimental study and finite element analysis. The experimental part of the paper used the Taguchi method to find the effects of printing internal geometry, printing speed, and nozzle diameter on the fatigue life of ABS and Nylon plastic materials. ANCOVA multiple linear regression and sensitivity analysis was used to investigate the effects of printing parameters on the fatigue life of materials. The analysis of the results revealed: Nylon performed better than ABS, but had a higher slope; the ‘tri-hexagon’ structure resulted in the highest fatigue life, but the effect was statistically significant only for ABS material; the fatigue life of both materials increased with decreasing the nozzle diameter; the printing speed had no statistically significant influence neither on ABS nor Nylon. The experimental results then were validated by numerical simulations and the difference between the values was within ±14% depending on the experiment. Such differences might occur due to numerical and experimental errors.

CO 2 -enhanced oil recovery (EOR) can have less GHG emissions compared to conventional oil production methods. The economy of CO 2 -EOR can significantly benefit from the recent rise of carbon prices in carbon markets due to its greenhouse gas (GHG) emission savings. This study conducted a life cycle assessment (LCA) of CO 2 -EOR in major hydrocarbon provinces of the world. Estimated net GHG emissions of CO 2 -EOR were compared with GHG emissions of average produced oil in the given country. When sourcing CO 2 from coal-fired power plants, Kazakhstan and China have net GHG emissions of CO 2 -EOR of 276 and 380 kg CO 2 eq/bbl, respectively, which are lower than the GHG emission factor of average oil produced in each of them. Significantly lower GHG emissions of CO 2 -EOR are observed in other hydrocarbon provinces (Iraq, Saudi Arabia, Kuwait, etc.), where CO 2 could be delivered from Natural Gas Combined Cycle (NGCC) power plants. However, the cost of CO 2 capture is higher at NGCC power plants than at coal-fired power plants. Further, we developed a techno-economic assessment (TEA) model of the CO 2 -EOR and integrated it with LCA to thoroughly consider carbon credits in its economy. The model was built based upon previous investigations and used statistics from a large industrial data set of CO 2 -EOR to produce accurate estimates of the CO 2 -EOR economy. The technical model iteratively estimated the balance of three fluids (crude oil, CO 2 , and water) in the CO 2 -EOR system with a 25 year operational lifespan and obtained actual data for the LCA and TEA models. The model was simulated for the Kazakhstan case with its oil market conditions for a demonstration purpose. TEA results showed that, with the available low-cost CO 2 capture source or high CO 2 cost in carbon trading, CO 2 -EOR can compete with current upstream projects in Kazakhstan by simultaneously increasing oil production and reducing GHG emissions.

This study aimed to identify the optimum printing parameters for the fused filament fabrication (FFF) of acrylonitrile butadiene styrene (ABS) and polyamide (nylon), to improve strength properties. For this purpose, the methodology of the paper involves an experimental study that used Taguchi’s method to identify the effects of the infill pattern, infill density, and printing speed on the mechanical properties of the materials. ABS and nylon plastic parts were tested in tension to failure. Based on the results of the tensile tests, it was found that ABS material produced the highest ultimate tensile strength when printed using a tri-hexagonal infill pattern, 100% infill density, and a printing speed of 65 mm/s. On the other hand, nylon material exhibited a better performance when printed using an octet geometric structure, with identical other parameters.