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The characteristics of black carbon and nitrogen oxide reduction versus the water content of emulsion fuel were studied by numerical methods, and a method of reducing fuel consumption was achieved by adjusting the turbocharger compression ratio. The results of the combustion period characteristics, versus the three types of emulsion fuel and the turbocharger compression ratios, shows that the combustion period is shortened in the order of CR00 > CR01 > CR02 > CR03, according to the compression ratio of the turbocharger. As the fuel water content increases, the combustion period is shortened in the order of EMDO16 < EMDO13 < EMDO10. The nitrogen oxide and black carbon reduction was because the combustion period increased, with increasing compression ratio, while the combustion period was shortened, with increasing moisture content of emulsion fuel. This also caused is an increase in the combustion pressure and a shortening of the combustion period, due to the expansion of the volume, in turn due to the micro-explosion of water. This may be due to the shortening of the post combustion period and the reduction of black carbon emissions. In addition, combustion was accelerated in the order—CR00 > CR01> CR02> CR03. By optimizing the water content of the emulsion fuel and turbocharger compression ratio, while considering the exhaust emission and combustion state, reduction of the fuel consumption rate and output improvement are shown. [ABSTRACT FROM AUTHOR]

Advanced dual control gate with surrounding floating gate (DC-SF) cell process and operation schemes are successfully developed for 3-D nand flash memories. To improve performance and reliability of DC-SF cell, new metal control gate last (MCGL) process is developed. The MCGL process can realize a low resistive tungsten (W) metal wordline, a low damage on tunnel oxide/inter-poly dielectric (IPD), and a preferable floating gate (FG) shape. Also, new read and program operation schemes are developed. In the new read operation, the higher and lower Vpass-read are alternately applied to unselected control gates to compensate lowering FG potential to be a pass transistor. In the new program scheme, the optimized Vpass are applied to neighbor WL of selected WL to prevent program disturb and charge loss through IPD. Thus, by using the MCGL process and new read/program schemes, the high performance and reliability of the DC-SF cell can be realized for 3-D nand flash memories. [ABSTRACT FROM PUBLISHER]

Exhaust gases from ships and automobiles have a significant impact on people and the environment. As a result, diesel engines used in land and marine vehicles are gradually being restricted, and low-carbon engines are under development. This study considers marine diesel oil (MDO) that is used in ships to meet the emission regulations required by the International Maritime Organization. This investigation explores the method and application technology for the reduction of nitrogen oxides (NOx) and particulate matter using emulsified fuel and mass-produced dimethyl ether (DME) fuel, which are analyzed. When comparing emulsified fuel and DME fuel to MDO, which is a ship oil, NOx are reduced by 20–45% and the particulate matter is reduced by 60–97%. When emulsified fuel containing moisture is used, the combustion chamber temperature is lowered due to the optimal expansion by moisture contained in the fuel. The particulate matter is also reduced. When DME fuel is used, it reduces the particulate matter by more than 97% in comparison with the existing MDO fuel and the emulsified fuel. The conditions are believed to be suitable for combustion and they can be satisfied by supplying oxygen during post-combustion. [ABSTRACT FROM AUTHOR]

As concerns regarding environmental pollution, energy security and future oil supply continue to grow, communities around the world are looking for non-petroleum-based alternative fuels along with advanced energy technologies (e.g., fuel cells) to increase energy use efficiency. Compared with the main alternative fuel candidates (e.g., methane, methanol, ethanol and Fischer–Tropsch fuels), dimethyl ether (DME) seems to have a significant potential to solve the aforementioned problems and can be used as a clean, high-efficiency compressed ignition fuel with reduced nitrogen oxide, sulphur oxide and particulate matter (PM) emissions. In this study, the results of experiments using a ship engine and numerical analysis were verified using AVL BOOST software. Based on these verifications, nitrogen oxide and PM reduction characteristics were numerically analysed by controlling the diameter and spraying time of the fuel nozzle, which is the fuel injection system of a marine engine. When DME fuel was used, nitrogen oxide and PM emissions were reduced by 40% and 90%, respectively, compared with marine diesel oil fuel. To prove the viability of DME as an alternative fuel, combustion and exhaust characteristics were analysed in accordance with injection timing and the variation of nozzle hole. [ABSTRACT FROM AUTHOR]

In this study, the exhaust gas characteristics of marine diesel oil (MDO) and emulsion fuels, which are currently used to reduce nitrogen oxides and particulate matters emitted from ship engines, were investigated through experimental and numerical analyses. The moisture included in the emulsion fuel primarily promotes the atomization of fuel due to microexplosion, and lowers the combustion temperature due to the latent heat of evaporation from the evaporation of moisture, thus reducing nitrogen oxides and particulate matter. In the case of emulsion fuel containing a water content of 16%, the combustion temperature was lowered, and the reduction rate of nitrogen oxide and black carbon was about 60% and 15%, respectively. The proposed method is a combustion control technology that can reduce particulate matter as well as nitrogen oxides by using emulsion fuel. [ABSTRACT FROM AUTHOR]