• Journal of the Mineralogical Society of Korea
• /
• v.30 no.4
• /
• pp.179-186
• /
• 2017

This study investigated the mineralogical characteristics of lime mortars used in pointing of Namhansanseon Yeojang from Joseon dynasty. Polarization microscopy revealed quartz, feldspar, mica, pyroxene and opaque minerals in the lime mortars. XRD analysis also confirmed clay minerals chlorite and kaolin. As a result of particle size analysis of lime mortars, the particle size distribution was wide and size was not uniform. 60% of samples were corresponded to the sand area. The chemical components detected from XRF analysis, 8.71-11.18 % of Ca as the main component of lime and $SiO_2$, $Al_2O_3$, and $Fe_2O_3$ in soil minerals were main components. The lime mortars showed an endothermic peak due to decarbonization reaction of $CaCO_3$ at $750^{\circ}C$ and weight reduction rate of 10%. The microstructures were agglomerated amorphous and observed rhombohedral calcite crystals by scanning electron microscope. It is considered that the pointing of Yeojang is a mortar mixed with lime and soil. In addition the Hanbongseong Yeojang was constructed using the same materials and construction technique because the minerals composition is not different according to the Yeojang location and use.

• Korean Journal of Microbiology
• /
• v.40 no.1
• /
• pp.37-42
• /
• 2004

To differentiate commercial bifidobacteia for Bifidobacterium lactis Bb-12, Bif. longum Bb-536 and Bif. infantis Maeil-K9, we studied the various carbon source, the nitrogen sources and antibiotics. Amygdalin and fructose were good candidates for carbon sources, and tryptone was suitable for nitrogen sources to design a new selective media for three commercial bifidobacteria. In the case of the amygdalin-containing medium as carbon sources, Bif. lactis Bb-12 and Bif. infantis Maeil-K9 showed good growth, and in fructose-containing medium, Bif. longum Bb-536 showed good growth. In antibiotics resistance study, the addition of 1 mg/L doxycyclin was very effective for differentiation of each bifidobacteria. Doxycyclin did not affect the growth of Bif. lactis Bb-12 and Bif. infantis Maeil-K9, but Bif. longum Bb-536 was completely inhibited by doxycyclin. Finally to confirm the selection capability of newly designed selective media, temperature-shocked bifidobacteria were cultured on them. As the results, fructose or doxycyclin containing medium showed for high growth for temperature-shocked bifidobacteria, but amygdalin containing medium showed low growth of temperature-shocked bifidobacteria.

• Korean Journal of Materials Research
• /
• v.9 no.12
• /
• pp.1252-1262
• /
• 1999

The effect of microstructures on the strength-flangeability of Nb bearing hot-rolled high strength steel was investigated in order to improve the strength-flangeability of conventional TS 580MPa grades HSLA steel for the automotive wheel disc. The low temperature coiling method using 3-step controlled cooling pattern after hot rolling was effective to produce the Nb-bearing high strength steel with the polygonal ferrite and bainite duplex microstructures. It was suggested that the suppressed precipitation of grain boundary cementites and the decreased hardness difference between ferrite matrix and bainite cause the excellent stretch-flangeability of ferrite-bainite duplex microstructure steel. Therefore, the formation and propagation of microcracks were suppressed relative to the conventional HSLA steel with ferrite and pearlite microstructure. In addition, the elongation was improved as compared with that of hot-rolled steel sheets using conventional early cooling pattern because the volume fraction of polygonal ferrite was increased.

• Korean Journal of Materials Research
• /
• v.2 no.5
• /
• pp.353-359
• /
• 1992

Thermal oxidation and plasma enhanced chemical vapor deposition of tantalum oxide thin films on p-type (100) Si substrates were studied to examine the dielectric nature of T$a_2O_5$ as a Al/T$a_2O_5$/p-Si capacitor. Microstructure and dielectric properties of the capacitors were investigated by XRD, AES, high frequency C-V analyzer, I-V meter and TEM. XRD analysis showed that the structure of T$a_2O_5$ films were amorphous, but the films were crystallized to hexagonal $\delta$-T$a_2O_5$ by 65$0^{\circ}C$ thermal oxidation treatment. It was found that the stoichiometry of the films was more or less close to 2 : 5. Leakage current density and relative dielectric constant of thermal oxidation T$a_2O_5$ film at 60$0^{\circ}C$ was 5.0${ imes}10^{-6}$/A/c$m^2 and 31.5, respectively. In the case of PECVD T$a_2O_5$film deposited at 0.47W/c$m^2 they were 2.5${ imes}10^{-5}$/A/$ extrm{cm}^2$ and 24.0, respectively. The morphology of the films and interfaces were investigated by TEM.

• Korean Journal of Materials Research
• /
• v.22 no.7
• /
• pp.346-351
• /
• 2012

$Li_{1+x}Al_xTi_{2-x}(PO_4)_3$(LATP) is a promising solid electrolyte for all-solid-state Li ion batteries. In this study, LATP is prepared through a sol-gel method using relatively the inexpensive reagents $TiCl_4$. The thermal behavior, structural characteristics, fractured surface morphology, ion conductivity, and activation energy of the LATP sintered bodies are investigated by TG-DTA, X-ray diffraction, FE-SEM, and by an impedance method. A gelation powder was calcined at $500^{\circ}C$. A single crystalline phase of the $LiTi_2(PO_4)_3$(LTP) system was obtained at a calcination temperature above $650^{\circ}C$. The obtained powder was pelletized and sintered at $900^{\circ}C$ and $1000^{\circ}C$. The LTP sintered at $900{\sim}1000^{\circ}C$ for 6 h had a relatively low apparent density of 75~80%. The LATP(x = 0.3) pellet sintered at $900^{\circ}C$ for 6 h was denser than those sintered under other conditions and showed the highest ion conductivity of $4.50{\times}10^{-5}$ S/cm at room temperature. However, the ion conductivity of LATP (x = 0.3) sintered at $1000^{\circ}C$ decreased to $1.81{\times}10^{-5}$ S/cm, leading to Li volatilization and abnormal grain growth. For LATP sintered at $900^{\circ}C$ for 6 h, x = 0.3 shows the lowest activation energy of 0.42 eV in the temperature range of room temperature to $300^{\circ}C$.

• Journal of the Korean Wood Science and Technology
• /
• v.33 no.1 s.129
• /
• pp.63-76
• /
• 2005

Wood-culture is new paradigm which is substituted for the cement culture, and the study of wood-culture should keep pace with not only the study of a engineering science but also a sociological study to form a theory system. The purpose of this study is to suggest the method of sociological approach of the wood culture which have not yet tried at home and abroad; in view of structural-functionalism, systemical-functionalism, conflict theory, social-change theory by analyzing cases in Korea. In view of structural-functionalism, social system consists of cognition system, institution system, life system and technology system. These sub-systems fulfill the function of what-should-be, reasonability, reality and development. In view of systemical-functionalism, according to the acknowledgment and spreading proccess of the wood usefulness, wood culture system consists of the individual system, organizational system and the social system. In view of conflict theory, the society which has the wood culture can be classified into three types. The one is society which the traditional wood culture is declining and the cement culture is spreading. The other one is society which the cement culture is declining and the traditional wood culture is spreading. Another is Finally the society which the two type balance with. In view of social-change theory, the society can be classified into three types. The one is society which the wood culture is proceeding to the cement culture. The other is society which the cement culture is proceeding to the wood culture. Another is society which the wood culture changes itself. Finally, from a view of changing level, the society can be classified into three types: the micro-change, the middle-level-change, and the macro-change. It's need to study wood culture systemically in view of engineering and sociological science. And then it will be possible to make 'wood culture theory system'.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.29 no.1
• /
• pp.46-50
• /
• 2015

Both Portulaca oleracea (PO) and Glechoma hederacea (GH) have been used as traditional medicine due to the multiple pharmacological activities. However, the effects of PO and GH in the pathology of periodontitis is still elusive. In this study, we examined anti-microbial activity of PO ethanol extract (POEE) and GH ethanol extract (GHEE) in vitro, and physiological effects of POEE and GHEE on the cell inflammatory responses and the severity of periodontitis were determined using the rat periodontitis model. Our results indicate that POEE and GHEE had no effects on the proliferation of streptococcus mutans and on LPS-mediated inflammatory responses in gingival fibroblast cells. Notably, ingestion of POEE and GHEE resulted in attenuating the severity of periodontitis and population change of immune cells. These data suggests that PO and GH should be considered as candidates for relieving the severity of periondontitis.

• Pediatric Infection and Vaccine
• /
• v.22 no.3
• /
• pp.136-142
• /
• 2015

The Korean Society of Pediatric Infectious Diseases (KSPID) has participated in the task force team consisting of government authorities as well as civil medical experts and facilities to block the spread of Middle East Respiratory Syndrome in 2015. KSPID posted the "Middle East Respiratory Syndrome (MERS) Pop-up" in the homepage of The Korean Pediatric Society and The Korean Society of Pediatric Infectious Diseases. KSPID also released the "Guidelines for testing for MERS in children and adolescents" and the "Instructions for the Operation of National Safe Hospital" for children and adolescents in a timely manner. Such actions were aimed to prevent unnecessary anxieties, studies and isolation of pediatric patients with respiratory symptoms and signs caused by other common microbial etiologies as being suspected for MERS patients. This strategy relieved the doctors and parents from unnecessary fear and prevented the loss of unnecessary health care costs, and has proven to be a well-judged guideline and management protocol as evaluated after the final end of MERS outbreak. KSPID and its members should support the presence of pediatric infectious disease (PID) specialists in every medium size hospitals in Korea by developing the need for consultation fees for PID consultation in the hospital based practice and promoting the potential for cost savings related to prevention of health care associated infections and optimal prescription of antimicrobial agents. KSPID and its members need to approach and develop a communication plan to political decision makers to demonstrate and convince them of the importance of a PID specialist service.

• Journal of Preventive Medicine and Public Health
• /
• v.19 no.2 s.20
• /
• pp.244-251
• /
• 1986

Sister chromatid exchanges(SCEs) and cell cycle kinetics were proposed as a sensitive and quantitative assay for mutagenicity and cytotoxicity in short-term cultures of phytohema-gglutinin(PHA)-stimu1ated human 1ymphocytes. Therefore, this study was performed to investigate the relation between the cytotoxic effects and sister chromatid exchanges. The resultes are summarized as follows: 1) The frequency of SCEs per cell are $13.1{\pm}2.8$ in the lower concentration of $6.25{\times}10^{-9}M\;and\;75.8{\pm}8.2$ in the highest concentration of $1.00{\pm}10^{-7}M$. Mitotic index is decreased in the higher concentration of mitomycin C. The result indicates that mitomycin C led to a dose dependent increase in SCE frequency, but decease in mitotic index. 2) Chromosomal analysis was performed on metaphase cells that have divided one, two, and three or more times for cell cycle kinetics by fluorescence-plus-Giemsa(FPG) technique. According to the increased concentration of mitomycin C, the proportion of metaphase cells in the first are profoundly increased but the cells of third division are greatly decreased. 3) The frequency of SCEs per chromosome by chromosomal group are decreased gradually from A group to G group. But relationships between specific chromosomal group and SCE frequency are not found.

• Journal of Preventive Medicine and Public Health
• /
• v.22 no.3 s.27
• /
• pp.313-322
• /
• 1989

The present status of the traffic accident rate in Korea shows that it is the highest in the world with a continuously increasing trend. Human factors account for 90% of the causes of traffic accidents. Therefore, the purpose of this study was to determine some human factors related to traffic accidents by studying the relationship between health status and traffic accidents. To accomplish this purpose, all taxi companies located in the Seoul area were divided in three groups according to the number of taxi possessed, then some companies in each ?roup were randomly selected for study, and a total of 222 drivers in those selected companies were questioned and examined from April 15 to April 22, 1989. Seventy drivers among 222 had experienced a traffic accident. A $x^2$-test was performed on the data, then, factor analysis and discrminant analysis were executed with the following results: 1. The drivers complaining of gastroenteric symptoms numbered 110(49.5%), which was the major symptom among all drivers complaining of poor health. 2. In the primary analysis, variables related to traffic accidents were divided into general, occupational, and health characteristics. Drivers having no traffic accident experience and drivers having that experience were subjected to question about age, educational level, residential status, monthly average income, working hours and days, degree of satisfaction with their profession and homelife, degree of worry about health. degree of fatigue, medication, drunken driving, and illness, but there were no statistical significances. 3. In the factor analysis, the 8 health variables which cause traffic accidents were classified into 3 common factors which were perceived health factor, sleeping and drunken driving, and visual acuity and smoking factor. Perceived health was the factor which contributed most to explaining accidents. 4. In the discriminant analysis, a correct prediction rate of 68.0% was obtained in the factors of all the characteristics. 5. Degree of sttisfaction with their homelife and educational and economic factor in the general characteristics, degree of satisfaction with their profession in the occupational characteristics, and sleeping and drunken driving in the health characteristics were selected as statistically significant factors to discriminant the traffic accident. 6. Among the factors of the general, occupational, and health characteristics, degree of satisfaction with their homelife, driving experience, family factor, perceived factor were selected as the statistically significant factors.