• Carbon letters
• /
• v.10 no.3
• /
• pp.202-207
• /
• 2009

Pitch-based carbon fiber tows were prepared from naphtha cracking bottom oil by reforming and carbonization. The relationship between exothermic heat and carbon contents of the fiber was investigated by changing the carbonization conditions. The carbon contents and the crystallinities of isotropic pitch-based carbon fibers were 86.8~93.8 wt% and 33.7~40.1%, respectively, which were linearly proportional to the increase of carbonization temperature from 700 to $1000^{\circ}C$. The exothermic heat (temperature increase) of fiber tows was measured in a short time, which was also linearly proportional to the increase of carbon contents due to the increase of crystallinity, even though the crystallinity was low. Therefore, the carbon contents or carbonization degree of fibers can rapidly and indirectly be estimated by measuring the surface temperature increase of fibers.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.20 no.10
• /
• pp.3282-3292
• /
• 1996

Flow velocity was measured using a hot wire anemometer. Turbulence intensity was in proportion to mean flow velocity regardless of swirl velocity. And integral length scale has proportional relation with swirl velocity regardless of measurement position. Flame speed calculated by radius of visualized flame was increased and then decreased according to lapse of time from spark. Maximum flame speed was increased according to increase of turbulence intensity. Burning speed and flame transport effect increased with increase of swirl velocity, but ratio of burning speed to flame speed decreased with increased of swirl velocity. Mass fraction burned versus volume fraction burned was increased in proportion to the increase of turbulence intensity, caused by increase of combustion promotion effect according to increase of turbulence intensity and scale.

• The Korean Journal of Physiology
• /
• v.3 no.1
• /
• pp.55-58
• /
• 1969

It was studied that which components of the ginseng are related to the effects that accelerate Saccharomyces division by comparing the influences of ginseng powder, alcohol extracts of ginseng, and linoleic and stearic acids which are known as the ginseng components on the division. The addition of ginseng powder and alcohol extracts of ginseng to the glucose agar medium marked the conspicuous increases of the division of Saccharomyces: 44% increase by 0.1% powder, 53% increase by 0.05% alcohol extracts. Also, the addition of the fatty acids of less than 0.0008% marked the considerable increases of the division: 22% increase by 0.0008% linoleic acid, 31% increase by 0. 00016% linoleic acid, 12% increase by 0.0008% stearic acid. Therefore it can be concluded that a proper amount of those fatty acids contained in the ginseng has a definite effect on the acceleration of Saccharomyces division.

• Textile Coloration and Finishing
• /
• v.20 no.1
• /
• pp.28-35
• /
• 2008

Texturing is the process of including a characteristic of a natural fiber in a synthetic fiber. The most common method of it the false twist texturing. Nylon textured yarn is primarily manufactured by the disk type. The major process parameters or the disk type false twist machine ratio, disk/yarn, and heater temperature. This study therefore investigated the effects of false twist texturing, especially speed and draw ratio, on the physical properties of nylon textured yarn. The increase of speed was proportional to the increase of unwinding tension, which could reduce the production efficiency by elevating the tension affecting to fiber during the process. In addition, the increase of speed was inversely proportional to the increase of crimp rigidity of nylon textured yarn. Draw ratio was proportionally increased with the increase of tenacity and the reductions of fineness and elongation, showing the influence or draw ratio to the ultimate physical properties of textured yarn.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.43 no.1
• /
• pp.116-121
• /
• 2001

This study is performed to examine the physical and mechanical properties of eco-concrete with polypropylene fiber. Test results show that the strengths are increased with increase of the content of natural gravel, excellent soil compound and polypropylene fiber. The coefficient of permeability is increased with increase of the content of the polypropylene fiber but it is decreased with increase of the content of natural gravel and excellent soil compound. The lowest coefficient of permeability is achieved by eco-concrete which it is 100 times lower than that of the control. The durability factor is increased with increase of the content of natural gravel and excellent soil compound, and decreased with increase of the content of polypropylene fiber.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2000.10b
• /
• pp.921-924
• /
• 2000

The purpose of this paper is to investigate the effects of admixture such as AE water reducing agent and Flyash on properties of cement mortar for floor. As for the effects of AE water reducing agent kinds, fluidity and air content increase in order for melamine type, lignine type and naphtalene type. As Flyash contents increase, fluidity shows high, but air content shows decline tendency. compressive strength according to AE water reducing agent kinds increase in order for melamine type, lignine type and naphtalene type. As AE water reducing agent content increases, it shows to be decreased. As for the effects of Flyash, it retards at early age but at later age it gains high with increase of Flyash contents due to pozzanic reaction. Drying shrinkage shows to be docreased slightly with increase of AE water reducing agent.

• YAKHAK HOEJI
• /
• v.56 no.1
• /
• pp.66-69
• /
• 2012

This study aims to assess the aggregate contribution of new drugs to the increase in life expectancy. We constructed a panel data combining mortality data in KOSIS and a drug dataset generated by assigning new drugs listed in 2000~2009 to their respective ICD codes. We found that 10% increase in stock of new drug led to 0.13~0.27% increase in the probability of survival to age 65. Due to lack of disease-specific life table, we used indirect approach to estimate the effect of new drugs on longevity. Using ordinary least squares, the estimate of the probability of survival to age 65 (logarithm) on life expectancy for all ages was 24.92. In conclusion, the increase in life expectancy of the entire population in Korea between 2000 and 2009 resulting from NMEs is 1.95 years, which explains 46.6% of real increase in life expectancy.

• Proceedings of the Safety Management and Science Conference
• /
• 2003.05a
• /
• pp.211-222
• /
• 2003

The health industry is highly value-added, compared to other industries. The reason is that increase of income growth and the expanded human life expectancy bring about positively needs of products at health industry. This is related with increase in expenses of health care and R&D investment of health industry. After 1995, the share of GDP at drug & biomedical industry is increased. Especially, the share of GDP at biomedical is 0.12% in 1995 1$^{st}$ quarter, but 0.17% in 2002 3$^{rd}$ quarter, 0.24% in 2008. Biomedical's contribution about GDP growth is to jump into 6.01% in 2008. The share of GDP at drug will continuously expand, compared to other manufacture industries. Also, drug's contribution about GDP growth will increase, compared with before. Conclusionally, total shares of GDP at drug St biomedical industry are to increase, compared with before. Also, this health industry's contribution is to expand as value-added industry and increase of sales.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2010.04a
• /
• pp.459-464
• /
• 2010

The dynamic propagation of an interface crack between two dissimilar functionally graded layers under anti-plane shear is analyzed using the integral transform method. The properties of the functionally graded layers vary continuously along the thickness. A constant velocity Yoffe-type moving crack is considered. Fourier transform is used to reduce the problem to a dual integral equation, which is then expressed to a Fredholm integral equation of the second kind. Numerical values on the dynamic energy release rate (DERR) are presented. Followings are helpful to increase of the resistance of the interface crack propagation of FGM: a) increase of the gradient of material properties; b) increase of the material properties from the interface to the upper and lower free surface; c) increase of the thickness of FGM layer. The DERR increases or decreases with increase of the crack moving velocity.

• Proceedings of the KOSOMBE Conference
• /
• v.1996 no.11
• /
• pp.327-330
• /
• 1996

Poly(L-leucine)(PLL)/poly(ethylene oxide)(PEO)/poly (L-leucine)(PLL) block copolymers were synthsized by polymerization of L-leucine N-carboxyanhydride with diamine-terminated PEO for possibility of wound dressing which may have several advantages such as 1) increase of solubility, 2) control of biodegradation, 3) absorption of body fluid. 4) non-immunogenic effect than PLL homopolymer wound dressing aleady commercialized. Water content increased with an increase of PEO content in the block copolymer due to the hydrophilicity of PEO. Release of silver sulfadiazine(AgSD) from AgSD loaded wound dressing increased with an increase of PEO content in the block copolymer. It was found that the number of Pseudomonas aeruginosa decrease with an increase of PEO content due to the fast release of antibacterial agents with an increase of PEO content in the block copolymer.