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Diesel exhaust contains a lower level of hydrocarbons, which serve as the reductant for the NOx catalyst, than gasoline engine exhaust. An investigation was made of several methods for maximizing the performance of NOx catalysts for direct-injection diesel engines. First, the catalysts were given an HC adsorption capability and then their characteristics were tailored to the HC species contained in diesel exhaust. This HC adsorption capability is designed to achieve better utilization of the HC species in diesel exhaust as a reductant. Second, catalyst performance was examined under passive and active conditions. Excellent catalyst performance was obtained under a passive condition, because at high engine loads, NOx catalysts with an HC adsorption capability can utilize HCs adsorbed under low engine load conditions to reduce NOx.

Experimental investigations were conducted with a direct-injection diesel engine to improve exhaust emission, especially nitrogen oxide (NOx) and particulate matter (PM), without increasing fuel consumption. As a result of this work, a new combustion concept, called Modulated Kinetics (MK) combustion, has been developed that reduces NOx and smoke simultaneously through low-temperature combustion and premixed combustion, respectively. The characteristics of a new combustion concept were investigated using a single cylinder DI diesel engine and combustion photographs. The low compression ratio, EGR cooling and high injection pressure was applied with a multi-cylinder test engine to accomplish premixed combustion at high load region. Combustion chamber specifications have been optimized to avoid the increase of cold-start HC emissions due to a low compression ratio.

Thermo plastic olefin(TPO) for automotive bumper has poor paintability and 1.1.1-trichloroethane vapor treatment is applied in order to improve the paintability. 1.1.1-trichloroethane has the function of not only degreasing, but also it etches and swells the substrate. This paper introduces an alternative technology of modified TPO substrate with functional group which was newly developed. Also developed were a waterborne primer and aqueous based cleaning to show effect on specially TPO without the use of 1.1.1-trichlororthane which will be phased out by the end of 1995 to meet the Montreal Protocol.

An electrically regenerable diesel particulate filter particularly suitable for small (less than 4.0 liters) diesel engines has been developed. The cartridge consists of a unique tubular heater which is wrapped with ceramic fibers. Two or more of these cartridges with integral heaters are used in building a diesel particulate filter system. The features of this cartridge are described along with performance results. Performance and durability data are presented under both steady state and transient operating conditions. System design using these cartridges in a forklift truck application is presented in this paper. Performance and durability data of the system is discussed.

From the viewpoint of waste treatment and natural resources conservation,there is a strong demand for the study of the technology whereby automotive coated bumpers collected from the market can be recycled into brand-new bumpers. One of the major subject matters for recycling bumper material is to retain the impact resistance of the substrate by separating out the flaky coating film. This is to report “Sandwich Injection Molding Technology” to fill the core layer with granulated polypropylene(PP) of used bumpers and the skin layer with virgin PP resin,eliminating the separation process of coated film from the substrate. Core layer material contains high-density-polyethylene(HDPE) additive which improves the impact resistance that may have been deteriorated by coating film residue. Also,the function of HDPE and mechanism to improve the characteristics of molded material are analyzed.

Nitrogen oxide (NOx) and particulate matter (PM) emissions of diesel vehicles are regarded as a source of air pollution, and there is a global trend to enforce more stringent regulations on these exhaust gas constituents in the early years of the 21st century. On the other hand, the excellent thermal efficiency of diesel engines is certainly a welcome attribute from the standpoints of conserving energy and curbing global warming. Recently, many research institutes around the world have been using high-efficiency direct-injection (DI) diesel engines to research emission control technologies. The authors have also been engaged in such research [1,2]. As a result of this work, we have developed a new combustion concept, called Modulated Kinetics (MK), that reduces NOx and smoke simultaneously due to low-temperature and premixed combustion characteristics, respectively, without increasing fuel consumption [3,4].

Coating the heat insulation materials on the combustion chamber walls is one of the solutions to reduce the cooling loss of internal combustion engines. In order to examine the coatings, the evaluation of the heat transfer coefficient and the analysis of the heat transfer phenomena on the heat insulated walls are important. Firstly, the highly-responsive wall temperature sensor is developed, and the instantaneous wall heat flux is measured to evaluate the heat transfer coefficient on the heat insulated walls. The results show that the Nusselt number on the heat insulated walls is less influenced by the Reynolds number variation than that on the metal walls. Secondly, the high speed µ-PIV is employed to analyze the various turbulent flow characteristics. The results show that the turbulent dissipation on the heat insulated walls is smaller than that on the metal walls.