• Journal of ILASS-Korea
• /
• v.24 no.4
• /
• pp.194-202
• /
• 2019

A mixture preparation strategy was proposed and evaluated in a diesel-natural gas dual-fuel engine to reduce hydrocarbon (HC) and carbon monoxide (CO) emissions under low load conditions. An experimental investigation was conducted in a single-cylinder compression-ignition engine. Natural gas was supplied with air during the intake stroke, and diesel was injected directly into the combustion chamber during the compression stroke. First, effects of diesel start of energizing (SOE) and natural gas substitution ratio on the combustion and exhaust gas emissions were analyzed. Based on the results, the mixture preparation strategy was established. A low natural gas substitution ratio and a high exhaust gas recirculation (EGR) rate were effective in reducing the HC and CO emissions.

• Proceedings of the Polymer Society of Korea Conference
• /
• 2006.10a
• /
• pp.375-375
• /
• 2006

The preparation methods are to be used as "melting method" and "absorption method", respectively. The reaction mixture in the reaction container was heating up the reaction mixture to $200^{\circ}C$ for 2 hour. The mixing time of lab scale preparation should be provided quit long, instead of the short working time in a compounder vessel. And The PP-PCM mixture in the reaction container was heating up the mixture around $60-80^{\circ}C$ for 2 hour. A melting method of frozen gel with 50/50 weight ratio of polypropylene-normal octadecane was prepared by adding PP chip and normal octadecane. An absorption method of frozen gel with 70/30 weight ratio of PP 4.8-normal n-octadecane was prepared by adding PP powder and normal octadecnae.

• Korean journal of food and cookery science
• /
• v.23 no.5
• /
• pp.644-649
• /
• 2007

In this study a purified protein was prepared from pork meat. The product consisted of 0.5% moisture, 3.0% ash, 5.5% ether extract and 88.7% crude protein. Also, a meat oligopeptide mixture was prepared from a pepsin digest of the protein preparation. The two preparations were colorless and odorless powders with low fat contents. The nutritive values of the pork meat protein and oligopeptide mixture were estimated by two methods, one using biological value(BV) and the other employing net protein utilization(NPU) by the nitrogen balance method. The meat oligopeptide mixture showed an excellent nutritive value by both methods. The true digestibilites of both the pork meat protein and the oligopeptide mixture were more than 98%. The above results indicate that the oligopeptide mixture is an excellent material as a dietary nitrogen source for many purposes.

• Korean Journal of Food Science and Technology
• /
• v.26 no.3
• /
• pp.231-238
• /
• 1994

The brined Chinese cabbages and kimchi seasoning mixture were separately stored and used for preparation of kimchi and the alternative method of conventional kimchi-manufacturing process was investigated. Chinese cabbages brined with 3% and 7% salt contents were stored at $0^{\circ}C$ and $10^{\circ}C$, and kimchi seasoning mixture without salt was stored at $4^{\circ}C$ and $10^{\circ}C$. The changes in pH and total acid of the cabbages were significantly slowly for the brined cabbage of 7% salt and storage at $0^{\circ}C$. Microbial growth including lactic acid bacteria were also increased slowly at $0^{\circ}C$. But, pH and total acid content of the kimchi seasoning mixture were not changed significantly at both temperatures during storage. Sensory evaluation on the kimchi samples showed that the modified method of kimchi preparation with separately stored seasoning mixture and brined cabbages is useful industrially or at home.

• Journal of Periodontal and Implant Science
• /
• v.28 no.2
• /
• pp.377-388
• /
• 1998

This double-blind controlled clinical and microbiological study was carried out to determine the effects of mouthwash preparation containing the mixture of herbal extract on developing plaque and gingivitis in the experimental gingivitis model. Following a 2-week normalization period, 34 dental students were distributed randomly into 1 of 3 treatment groups. They rinsed, under supervision, two times daily for 3 weeks with either normal saline(CT), 0.1% chlorhexidine(CH), or the mixture of herbal extract (HT), but refrained from any oral hygiene measures. The Plaque Index(PlI), the Gingival Index(GI), and the amount of Gingival Crevicular Fluid(GCF) were measured at week 0,1,2, and 3 of the experimental period, while the assessment of total wet weight of plaque and the phase contrast microscopic examination of plaque were performed at the end of experimental period(3 weeks). Subjects using mouthrinse preparation containing the mixture of herbal extract demonstrated negligible, if any, changes in the accumulation and microbial composition of plaque compared to those using normal saline, while the reduction of gingival inflammation by this mixture was highly significant and comparable to that of chlorhexidine. The results of this study indicate that the preparation containing the mixture of herbal extract do not provide any antiplaque benefits but is very effective in inhibiting the development of and in reducing existing experimental gingivitis when used as mouthrinse. Further research is needed to determine whether a significant reduction of gingival inflammation without a concomitant decrease in plaque accumulation is of clinical importance.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.10 no.4
• /
• pp.15-22
• /
• 2002

As the emission regulations on the automobiles have been increasingly stringent, precise control of air/fuel ration is one of the most important issues on the gasoline engines. Although many researches have been carried out to identify the fuel transport phenomena in the port fuel injection gasolines, mixture preparation in the cylinder has not been fully understood due to the complexity of fuel film behavior, In this paper, the mixture preparation during cold engine start is studied by using a Fast Response Flame ionization Detector.(FRFID) In order to estimate the transportation of injected fuel from the intake port into cylinder, the wall wetting fuel model was used. The two coefficient($\alpha$,$\beta$) of the wall-wetting fuel model was determined from the measured fuel mass that was inducted into the cylinder at the first cycle after injection cut-in. $\alpha$( ratio of directly inducted fuel mass into cylinder from injected fuel mass) and $\beta$ (ratio of indirectly inducted fuel mass into cylinder from wall wetted fuel film on the wall) was increased with increasing cooling water temperature. To reduce a air/fuel ratio fluctuation during cold engine start, the appropriate fuel injection rate was obtained from the wall wetting fuel model. Result of air/fuel ratio control, air/fuel excursion was reduced.

• Elastomers and Composites
• /
• v.41 no.1
• /
• pp.3-9
• /
• 2006

Optimal conditions for preparation of starch/PVA blends were investigated with the consideration of factors that may influence mechanical properties of the blends. Multiplex mixture optimal method as a statistical method were performed and then tensile strength, strain at break, Young's modulus and tear strength of films of the blends were measured to determine the optimal conditions for preparation. The mechanical properties needed for the degradable agricultural mulch were the target of this experiment. Results showed that although the strain at break was a little insufficient, the other properties were very close to the target. This means that the mechanical properties of the film from this blend as a whole are very compatible with those of the reference mulch.

• Journal of the Korean Ceramic Society
• /
• v.41 no.9
• /
• pp.703-708
• /
• 2004

The variation of the reaction pressure and reaction product during the reaction was investigated according to the total mass of the reaction mixture at the optimum composition for the preparation of u-Si3N4 powder which had been confirmed in the former investigation; 'Preparation of $\alpha$-Si$_3$N$_4$ powder in reaction system containing molten salt by SHS - part 1. synthesizing of powder'. When the total mass of the reaction mixture was 100g, the minimum pressure for a complete reaction was 60atm in 5L reactor, whereas the reaction was incomplete in the case that the mass exceeded 200g because of pressure increase. Also, as the mass of the reaction mixture increased, the reactivity linearly decreased. Hence, the complete reaction was realized by decreasing an initial $N_2$ pressure, and thus obtained minimum initial pressure was recorded 20 atm for the initial mixture of 500g. The reason of the incomplete reaction with pressure Increase was found to be that NH$_4$Cl vapour which was suppressed by the gas pressure acted as a diluent.

• Journal of the Korean Ceramic Society
• /
• v.40 no.2
• /
• pp.132-138
• /
• 2003

The effect of synthesis condition, type of starting materials, mole ratio, mixing. aging, and crystallization temperature and time, on the size of FAU-type zeolite has been studied. Different mixing route may lead to the different phase of zeolite even with the same starting materials. In general, the size of particles is smaller after aging, especially at lower aging temperature. Two step mixture gel preparation method resulted to not only the reduction of crystallization time but also that of particle size, but without the aging of two mixture gels before the preparation of the overall gel in the second step, only the crystallization time was reduced, not the particle size. The FAU-type zeolite with average particle size 0.4$\mu$m and BET surface area 838 $m^2$/g was obtained from starting materials of liquid sodium silicate, sodium aluminate, and sodium hydroxide with two step preparation of mixture gel, aging of the mixture gels in two steps, which effectively reduced the crystallization time and particle size.

• Journal of ILASS-Korea
• /
• v.1 no.3
• /
• pp.60-66
• /
• 1996

Finely atomized fuel droplet and good mixed mixture plays very important in improving combustion efficiency in an spark ignition engine. And combustion efficiency has influence directly on the engine power, fuel consumption rate and pollutant emission. In this study, perforated throttle valve which has relatively low value of PR has been developed and studied for the purpose of improving those aims. As a result of this study, it has been verified that the perforated throttle valve makes droplet more finely, and also proved that has a function of contributing to form good mixed mixture, especially in mixture preparation system of carburetor or SPI type spark ignition engine.