• Journal of Hydrogen and New Energy
• /
• v.21 no.5
• /
• pp.442-451
• /
• 2010

This paper describes the calculation method to obtain the product composition of coal pyrolysis at high pressure and high temperature. The products of coal pyrolysis should be determined for the coal gasifier simulation, and this is the first step of the coal gasifier simulation. The pyrolysis product distribution greatly affects the coal gasifier efficiency such as carbon conversion, cold gas efficiency and the syngas composition at the outlet of the gasifier. The present calculation method is based on the coal ultimate/proximate analysis and several correlations among gasifier pressure, coal properties and pyrolysis products. The calculated products for 5 coals have been compared with those from the commercial pyrolysis model.

• Proceedings of the Korean Powder Metallurgy Institute Conference
• /
• 2006.09a
• /
• pp.627-628
• /
• 2006

The present work is a study on the argon gas pressure effects of Sinter/HIP sintering on microstructure and strength of different grades of TiC-NiMo cermets. Titanium carbide in the composition of different grades of TiC-NiMo cermets was ranged from 40 to 80 wt.% and the ratio of nickel to molybdenum in the initial powder composition was 1:1, 2:1 and 4:1 respectively. On the sintered alloys, the main strength characteristic, transverse rupture strength (TRS) was measured. Furthermore, the microstructure parameters of some alloys were measured and the pressure effect on pore elimination was evaluated. All the results were compared with common, vacuum sintered alloys. The TRS values of TiC-NiMo cermets could be considerably improved by using Sinter/HIP technique, for high-carbide fraction alloys and for alloys sintered at elevated temperatures.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.15 no.5
• /
• pp.455-459
• /
• 2002

I have investigated the effects of annealing on a polymeric $\alpha-C_3N_{4.2}$ at high pressure and temperature in the presence of seeds of crystalline carbon nitride films prepared by a high voltage discharge plasma. The samples were evaluated by x-ray photoelectron spectroscopy (XPS), infrared spectroscopy, Auger electron spectroscopy and x-ray diffraction(XRD). Notably, XPS studies of the film composition before and after annealing demonstrate that the nitrogen composition in $\alpha-C_3N_{4.2}$ material initially containing more than 58% nitrogen decreases during the annealing process and reaches a common, stable composition of ~43%. XPS analysis also shows that the nitrogen composition in the annealed films without polymeric $\alpha-C_3N_{4.2}$ was reduced from 35% to 17%. Furthermore the concentration of the sp$^3$bonded phase increased with the increment of the annealing temperature.

• Transactions of the KSME C: Technology and Education
• /
• v.2 no.2
• /
• pp.105-111
• /
• 2014

Generally the lower part of the Earth's atmosphere, which is 20km above the ground, is called "air." The composition of this area is almost consistent consisting of nitrogen, oxygen, and other gases. Air density refers to the mass per unit volume of earth atmosphere. Though air is made of the mixed gases in a constant composition, the water vapor is one of the very changeable components. The density of moist air is lower than the dry one at the same temperature and pressure. As the density varies according to the pressure and temperature, this paper attempts to explore the main factors in the air quantity calculation by examining first the density calculation process according to the air property, and second the relation between the actual and standard air flow.

• Journal of the Korean Wood Science and Technology
• /
• v.17 no.2
• /
• pp.65-73
• /
• 1989

Steam explosion process is an efficient pretreatment method for sparating and utilizing wood main components has attracted attention in utilization of ligno-cellulosic biomass. In order to obtain the effective pretreatment condition. this study was made explosion apparatus. examined the composition. extraction of exploded wood. Wood chips of pine(Pinus densiflora oak (Quercus serrata) and birch wood (Belula platyphylla var. japonica) were treated with a high pressure steam(20-30 kg/$cm^2$, 2-6 minutes). The results can be summarized as follow; In analysis of exploded wood(EXW). It was found arabinose residues rapidly decreased with increasing of steaming time and pressure. Extractives of EXW with sodium hydroxide increased with increasing of steaming-time and- pressure especially extractives 1% sodium hydroxide has higher than other extracted method extractives of hard wood(oak, birch) has higher than pine wood. In EXW extracted with sodium hydroxide and methanol lignin was partially delignified alkali extraction was more delignified than methanol extraction hardwood than pine wood.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.5 no.4
• /
• pp.1-20
• /
• 1997

The automotive industry as the major industry of the nation has affected both society and economy since the automobile was invented, and the main technique that help to performance improvement of the automobile has been developed. But, the painting technique lags behind the main technique of the automobile because that was neglected. Specially, we can say that in case of the painting technique of the automobile of our nation is so weak situation. After we changed the injecting pressure, the composition ratio (paint, hardener, thinner) and the injecting flow rate from spray-gun by PDPA, we studied the character of the injecting velocity and droplet size, and found the fittest condition. So, we got the following result to help mending paint technique of automobile surface. We could know the following fact from the experiment result. When it does mending paint of automobile, there is most suitable that to inject the paint as injecting pressure 200∼300 kPa and to inject the ratio of paint 10 : 1 : 1 when the fluid adjective knob valve spay-gun is open full.

• Research in Community and Public Health Nursing
• /
• v.19 no.4
• /
• pp.545-553
• /
• 2008

Purpose: This study was conducted to test the effect of a 12-week exercise program on body composition. blood pressure, blood glucose, blood lipid and bone mineral density for middle-aged and aged women in rural areas. Methods: The subjects were 33 women at the age of 40-75. For statistical analysis, descriptive statistics and paired t-test were used with SPSSWIN 16.0. Results: The results were summarized as follows. First, body weight, BMI. % body fat. abdominal adipose, and waist circumference of the women decreased significantly after implementing the 12-week exercise program. Second, diastolic blood pressure, serum cholesterol, triglyceride, and LDL decreased significantly, and the HDL level increased significantly after the 12-week exercise program. Third, bone mineral density did not increase significantly after the program. Conclusion: These results suggest that the exercise program has an effect in decreasing body composition, and improving blood pressure, blood glucose, and blood lipid in middle-aged and aged women.

• Bulletin of the Korean Chemical Society
• /
• v.18 no.1
• /
• pp.56-61
• /
• 1997

Lead zirconate titanate (PZT) thin fills were deposited onto the Pt/Ti/SiO2/Si substrate by the pulsed laser deposition with the second harmonic wavelength (532 nm) of Nd:YAG laser. In order to determine the optimum conditions for the film deposition, the phase of the films were investigated as functions of ambient oxygen pressure, substrate temperature, and laser fluence. Also the chemical composition analysis was conducted for the PZT films deposited under various ambient oxygen pressure. When the distance between substrate and bulk PZT target is set to 20 mm, the optimum conditions have been determined to be 3 torr of oxygen pressure, 1.5 J/cm2 of laser fluence, and 823-848(±10) K range of substrate temperature. At these conditions, perovskite phase PZT films were obtained on platinized silicon. The chemical composition of the films is very similar to that of PZT bulk target. The physical structure of the deposited films analyzed by scanning electron microscopy shows a columnar morphology perpendicular to the substrate surface. Capacitance-Voltage hysteresis loop measurements show also a typical characteristics of ferroelectric thin film. The dielectric constant is found to be 528 for the 0.48 μm thickness of PZT thin film.

• The Journal of Korean Obstetrics and Gynecology
• /
• v.36 no.2
• /
• pp.1-19
• /
• 2023

Objectives: The purpose of this health promotion project for Korean medicine is to promote the health of climacteric women in Boeun-gun. Methods: During the project, pressure needle acupuncture treatment, herbal medicine treatment, meditation pore therapy, and health education were conducted. To evaluate the results, basic health surveys (body height, body composition test, blood pressure etc.), female hormone tests, Kupperman's index (KI), Menopause-specific quality of life questionnaire (MENQOL), and Perceived stress scales (PSS) were conducted. Results: No significant change was observed in the body composition test and blood pressure after the project. Follicle stimulating hormone (FSH) was significantly increased after the project, but Luteinizing Hormone (LH) and total estrogen levels were not significantly changed. KI and MENQOL scores significantly decreased after the project, and significantly decreased in 4 out of 11 items of KI and 3 out of 4 domains of MEMQOL. No significant change was observed in the PSS score after the project. Conclusions: From the results of this project, it can be seen that the Korean medicine health promotion project can help alleviate symptoms of climacteric syndrome and postmenopausal syndrome.

• 순환기질환의공학회:학술대회논문집
• /
• 2005.12a
• /
• pp.21-22
• /
• 2005