Applied Mechanics and Materials Vol. 492

Abstract: Experiment of fuel combustion and emission characteristics was carried on a turbocharged intercooled electronically controlled high pressure common rail diesel engine with n-butanol/diesel blends, then the results of experiment were compared and analyzed. The results show that with the adding of n-butanol, the maximum combustion pressure gradually increases and the maximum heat release rate gradually reduces; compared with diesel, CO emissions of the blends are slightly lower and decrease with the increasing load; HC emissions of the mixture fuel are higher and decrease first then increase with the increasing load; at 2000rpm, NO_X emissions of the blends are a little lower than the pure diesel in small loads but higher in other loads, and increase with the adding of the load.

Abstract: Zinc Oxide (ZnO) films were deposited by Atomic Layer Deposition (ALD) using Diethylzinc and a combination of Water and Ozone as the precursores. Electrical conductivity of ALD grown ZnO films, under low field, were studied with varied partial pressure of the constituent reactants. Supressing the oxygen vacancy by introducing O₃ during the reaction increase the resistivity of the films by couple of orders of magnitude. UV-Vis spectroscopy measurement showed the films to be transparent giving a room for its application as a TCO in solar cell.

Abstract: V_0.3Mo_0.7O₃ and V_0.6Mo_0.4O₃ nanoparticles were synthesized through reducing acidified vanadate and molybdate solution at around 60-70°C. The catalysts are aimed to be used as anode in alkaline fuel cells. BET and SEM analysis are done to characterize the obtained particles. According to the SEM results, both compounds were formed in nanosized particles and BET results showed that BET surface area of V_0.3Mo_0.7O₃ catalyst has 5 times higher than that of V_0.6Mo_0.4O_3.

Abstract: MgO/Al2O3 catalysts with 10 and 20 wt.% MgO loadings have been prepared by incipient wetness impregnation method. A low-surface area alumina with small pore sizes was used as catalyst support to stabilise most of the MgO particles on the external surface area of the support. The prepared catalysts were subsequently tested in the conversion of a waste vegetable oil to biodiesel. The waste vegetable oil conversion was found to increase with the increase in reaction temperature, reaction time and MgO loading in the catalyst.

Abstract: ChemCad 6.4 simulation package was used to model a two-step biodiesel production process from waste vegetable oils (WVO) and ethanol using homogeneous acid and alkali catalysts respectively. The developed process flowsheet consisted of pre-esterification and transesterification of WVO, ethanol and glycerol recovery, and biodiesel refining. The energy required for each processing unit as well as the energy required for the whole process have been estimated. Ethanol recovery accounted for the highest portion of the energy required for the entire process estimated as 2.75 MJ per kg of biodiesel produced.

Abstract: A modified YSZ thermal barrier coating (TBC) was prepared by simultaneously depositing two components, NiCrAlY and YSZ, on nicked-based superalloy DZ125 via atmospheric plasma spraying. In this study, the sodium salt was deposited on substrate surface at the deposition rate of 3 mg/cm^-2. After being heated at 950 °C for 50min, the specimens were cooled to ambient temperature within 10 min. The specimens were recoated after each 10 cycles. Subsequently, the corrosion products were analyzed via X-Ray diffraction and SEM. The results indicated that deterioration of traditional YSZ coating mainly resulted from the fluxing of thermal grown oxides (TGO). Conversely, abnormal growth of TGO and enrichment of molten salt around segmentation crack were not observed in the modified YSZ thermal barrier coating. Moreover, the modified YSZ-TBC exhibited higher thermal resistance than traditional YSZ-TBC in the thermal cycling testing.

Abstract: In this work, a three dimensional, single channel model of high temperature polymer electrolyte fuel cell is simulated. The effect of operating temperature and doping on performance is evaluated for a single channel model. A good agreement is observed between the predicted results and experimental values. The experiments have been performed under similar conditions by operating a cell with phosphoric acid doped PBI membrane of active area 49 cm². The results indicate that it is possible to obtain good performance in high temperature fuel cells by higher acid doping and operating at elevated temperature. The model has been conveniently implemented by customization of the material properties functions in the fuel cell module.

Abstract: Pr doped SnO₂ particles as negative electrode material of lithium-ion battery are synthesized by the coprecipitation method with SnCl₄·5H₂O and Pr₂O₃ as raw materials. The structure of the SnO₂ particles and Pr doped SnO₂ particles are investigated respectively by XRD analysis. Doping is achieved well by coprecipitation method and is recognized as replacement doping or caulking doping. Electrochemical properties of the SnO₂ particles and Pr doped SnO₂ particles are tested by charge-discharge and cycle voltammogram experimentation, respectively. The initial specific discharge capacity of Pr doped SnO₂ the negative electrode materials is 676.3mAh/g. After 20 cycles, the capacity retention ratio is 90.5%. The reversible capacity of Pr doped SnO₂ negative electrode material higher than the reversible capacity of SnO₂ negative electrode material. Pr doped SnO₂ particles has good lithiumion intercalation/deintercalation performance.

Abstract: This work focuses on synthesis of molybdenum oxide (MoO₃) by Atomic layer deposition (ALD) using molybdenum hexacarbonyl [Mo (CO)₆] and ozone. In-situ growth characteresticswerestudied by Quartz Crystal Microbalance (QCM). ALD temperature window for this material lies between 165 to 175°C giving a maximum growth rate of 0.45 Å per ALD cycle. Negligible nucleation was found by QCM studyindicating a linear growth of the film. Effect of different oxidants on the growth rate is also studied.As-deposited film is amorphous in nature which converts to monoclinic-MoO₃ after annealing as seen by taransmission electron microscopy.

Abstract: The modern society is, nowadays, facing two major problems: the energy sources depletion and the degradation of the ecologic system because of wastes rejection. The energetic valorization of wastes contributes on the resolution of both problems. In the present work, a feasibility study of an industrial pilot scale installation for the production of biodiesel from waste grease traps is lead. The installation is meant to transform 1000 tons of fat trap grease per year to biodiesel by transesterification. The daily production of the unit reaches 3200 l of biodiesel. All necessary equipments were sized following process engineering design and based on lab scale optimization experiments. Installation energy balance was also realized and it showed that the energy required for the installation functioning does not exceed 3.5% of the heating value of produced biodiesel.