• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.252-257
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• 2005

Injection molding is a very important industrial process for the manufacturing of plastics objects. During an injection molding process of composites, the fiber-matrix separation and fiber orientation are caused by the flow of molten polymer/fiber mixture. As a result, the product tends to be nonhomogeneous and anisotropic. Hence, it is very important to clarify the relations between separation' orientation and injection molding conditions. So far, there is no research on the measurement of fiber orientation using image processing. In this study, the effects of fiber content ratio and molding condition on the fiber orientation-angle distributions are studied experimentally. Using the image processing method, the fiber orientation distribution of weld-line in injection-molded products is assessed. And the effects of fiber content and injection mold-gate conditions on the fiber orientation are also discussed.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.7
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• pp.76-85
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• 1999

GDI(Gasoline Direct Injection( engine technology is well known as a new technology since it can improve fuel consumption and meet future emission regulations. But the GDI has many difficulties to be solved, such as complexity of injection control mode, unburned hydrocarbon, and restricted power. A 2-D shape combustion chamber was adopted to investigate mixture formation and combustion characteristics of GDI engine. Spray and combustion experiments were performed by changing the injection timing. injection pressure an din-cylinder flow in Rapid Compression and Expansion Machine(RCEM).Through the experiments, the detailed characteristics of fuel spray and combustion was analyzed by visualizing the in-cylinder phenomena according to the change of injection condition, and the optimal fuel injection timing and fuel injection pressure were obtained.

• Journal of Korean Society for Quality Management
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• v.30 no.2
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• pp.86-98
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• 2002

Defining the relationship between the quality of injection molded parts and the process condition is very complicate because of lots of factor are involved and each factor has a non-linearity. With the development of CAE(Computer Aided Engineering) technology, the estimation of volumetric shrinkage of injection mold parts is possible by computer simulation even though restricted application. In this research, Neural Network applied for finding optimal processing condition. The percent of volumetric shrinkage compared on each case and show neural network can be successfully applied selecting optimum condition not only within factor level but also between factor level.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.481-484
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• 2004

A form of measured temperature distribution to estimate condition of a electrical apparatus is a absolute reference for condition of the apparatus, time rate of transition, and difference between reference and currently temperature. Because passive thermography which has not injection of external thermal stimulation shows difference of temperature being on surface of a structure and temperature difference between the structure and back ground, the result could apply only to estimation or monitor for condition of terminal relaxation and overload related with temperature rising. However, a thermal flow in active thermography is differently generated by structure and condition of surface and subsurface. This paper presents the nondestructive testing using the properties and includes the results by heat injection and cooling to the apparatus. The buried discontinuity of subsurface could be detected by these techniques.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.6
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• pp.30-37
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• 2007

The injection and spray characteristics of top-feed type injector was investigated under liquid phase injection fueled with liquefied petroleum gas (LPG). Different pressures and temperatures of fuel injection system were tested to identify the injection characteristics after hot soaking. MIE-scattering technique was used for verification of successful liquid phase injection after hot soaking. In case of bottom-feed type injector, the injection was accomplished at every experimental condition. In case of top-feed type injector, when the pressure of LPG was over 1.2 MPa, the injection was not executed. However, under the pressure were 1.2 MPa, the liquid phase injection after hot soaking was accomplished. The engine with top-feed type fuel injection equipment was restarted successfully after hot soaking.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.7
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• pp.80-87
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• 2002

Liquefied petroleum gas (LPG) is used in spark ignition (SI) engines. Fuel injection rate of an injector is affected by fuel temperature and pressure in LPG liquid injection systems for either a multi-point-injection (MPI) or a direct injection (DI) engine. Even fuel injection conditions are varied, the air-fuel ratio should be accurately controlled to reduce exhaust emissions. In this study, a correction factor fur the fuel injection rate of an injector is derived from density ratio and pressure difference ratio. A compensation method of injected fuel amount is proposed for a fuel injection control system. The experimental results for the LPG liquid injection system in a SI engine show that this system works well fur a full range of engine speed and load condition, and the air-fuel ratio is accurately controlled by the proposed correction factor.

• Clean Technology
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• v.13 no.4
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• pp.300-307
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• 2007

The combustion characteristics of diffusion flame formed in the wake of a cylindrical stabilizer with varying fuel injection angle were studied. This study was performed by measuring the flame stability limits, lengths and temperatures of recirculation zones of flames, turbulence intensity in the wake of stabilizer, and concentration distribution of combustion gas, and by taking photographs of flames. The flame stability limits are dependent on fuel injection angle and main air velocity. The length and temperature of recirculation zone are dependent on fuel injection angle. As the length of the recirculation zone is decreased, the flame shows more stable behavior. The temperature of recirculation zone has a maximum value at the condition of theoretical mixture. The flame stability is enhanced when the temperature in the recirculation zone decreases. The turbulence intensity in the wake of stabilizer is independent of the fuel injection angle, but it is affected by stabilizer itself and main air flow condition. If the stabilization characteristics of flame is good, the concentration of $C_3H_8$ is high, but the concentration of $CO_2$ is low at the boundary of recirculation zone. The combustion characteristics of diffusion flame can be controlled by changing the fuel injection angles. The appropriate fuel injection angle should be selected to get high combustion efficiency, high load power, low environmental pollution, and clean combustion condition of fuel.

• Journal of Pharmacopuncture
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• v.7 no.1 s.12
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• pp.15-26
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• 2004

Background : This study was conducted to evaluate the effects of wild ginseng herbal acupuncture developed for the intravenous use. Healthy male and female volunteers(n=57) went through Randomized Control Trials(RCT). Methods : For those who are under a medication due to common cold or other illnesses were excluded in the primary stage and the subjects with possible abnormalities in the pre-screening process were also excluded in the secondary stage. Then the examination groups were determined by random sampling. Experiment groups were divided into Normal saline injection group(control group), cultivated wild ginseng herbal acupuncture group(experiment group 1) and natural wild ginseng herbal acupuncture group(experiment group 2) Blood tension, body temperature, pulse, and other criteria were measured and analyzed. Results : 1. Intravenous injection of cultivated wild ginseng herbal acupuncture and natural wild ginseng herbal acupuncture didn't cause significant changes in the blood tension, pulse, body temperature, and etc. 2. No significant differences were witnessed in CBC, ESR, biochemistry of blood test and UA between the experiment groups. 3. No significant changes were noted in the thermography before and after the test in the experiment groups. 4. Some of the common physical changes occurring during and after the administration were fatigue, chest distension, and headache in all of the experiment groups. 5. Comparing general condition after one week from the termination of administration, the control group showed worst condition while as the natural wild ginseng herbal acupuncture group displayed best condition. Conclusion : From the above results, we can carefully deduce that the intravenous injection of the wild ginseng herbal acupuncture didn't show significant differences compared to injection of the normal saline. We can infer it is safe on the human body and further studies and reports must be followed.

• Korean Journal of Clinical Pharmacy
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• v.9 no.1
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• pp.71-76
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• 1999

The stability of penicillin G potassium injection after reconstitution was evaluated in two different diluents of sodium chloride $0.9\%$ and dextrose $5\%$ in water stored at room temperature or refrigerated condition. The concentrations of penicillin G, stored for 24 hours at room temperature or for 10 days at refrigerated condition, were determined by HPLC. Also the pHs of the reconstituted solutions were monitored. The concentrations and pHs of penicillin G potassium 500,000 U/ml injection after reconstitution gradually decreased in all conditions. Stored at room temperature after reconstitution, a new peak which suspected as degradation products of penicillin G was detected in 5 hours in sodium chloride $0.9\%$, 4 hours in dextrose $5\%$ in water. At refrigerated condition, the new peak was detected in 4 days in both sodium chloride $0.9\%$ and dextrose $5\%$ in water. The degradation products of penicillin G allergy have been thought to be one of the substances responsible for evoking allergic reactions. In conclusion, the penicillin G potassium 500,000 U/ml injection after reconstitution was stable for 4 hours in sodium chloride $0.9\%$ 3 hours in dextrose $5\%$ in water solution at room temperature. At refrigerated condition, both solutions were stable for 3 days after reconstitution.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.3
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• pp.249-256
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• 2000

In order to investigate the effectiveness of methanol, which has high latent heat of evaporation and oxygen contents, for DI diesel engine performance and exhaust emission, the methanol was injected at the suction port of DI diesel engine. The injector used for test was conventional gasoline engine injector and controlled the quantity of methanol per cycle by the power supply controller which designed specially for injector. The results shown that the maximum pressure point was delayed, the value of maximum pressure was decreased, and the concentrations of both NOx and Soot were decreased, as the methanol injection quantity increased, and also the thermal efficiency of engine injected methanol under the high load condition was similar to no methanol injection but under the medium load condition was decreased within the experimental conditions.