• 한국석유지질학회:학술대회논문집
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• autumn
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• pp.28-46
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• 2001

Natural gas is a mixture of hydrocarbon gases and impurities such as nitrogen, hydrogen sulfide, and carbon dioxide and a clean energy producing no pollution materials for combustion. Currently, the demand of the natural gas is rapidly increasing due to worldwide environmental problems. According to Hubbert's study in the past, the natural gas was predicted as rapidly depleted resources, and then the results led to high gas price and limitation of usage during 1980s. Afterward, the study of natural gas resources based on geology identified the additional natural gas resources that were not considered in Hubbert's study. They are unconventional gas, additional resources in the existed reservoirs, and natural gas in deep subsurface areas. Such additional resouces made the future of natural gas bright and pormised low and stable gas price in the future. Deep natural gas is defined as the gas existing at or below 15,000ft$(4,752{\cal}m)$ in depth from the surface. According to the study from the U.S. Geological Survey(USGS) in 1995, 1,412 TCF of technically recoverable natural gas was remained to be discovered or developed in the onshore of United States. A significant part of that resource base, 114 TCF, exists at deep sedimentary basins, and it shows wide distribution with various geological environments. In 1995, the deep gas contributed to $6.7\% of total supply amount of natural gas in the United States and is expected to be $18.7\% by 201.5. However, the development of the deep gas is a high risky business due to expensive investment and high portion of dry holes, although it is developed. Thus, for developing the deep gas economically, it is necessary to overcome many technical challenges. In this paper, for increasing success rate of the deep gas, 1) geologic and compositional characteristics, and production cost have been analyzed according to depth, 2) technical problems related to deep gas production have been summarized, and 3) finally future study areas for increasing application of the deep gas have been suggested. For reference, this paper was written based on the study results from USGS and Gas Research Institute(GRI), for the United States is doing the most active R&D in the deep gas area, and thus, has many reliable data.

• Journal of the Korean Vacuum Society
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• v.6 no.4
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• pp.348-353
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• 1997

Hydrogenated amorphous carbon(a-C:H) films were deposited on p-type Si(100) by DC saddle-field plasma enhanced CVD to investigate the effect of substrate bias on optical properties and structural changes. They were deposited using pure methane gas at a wide range of substrate bias at room temperature and 90 mtorr. The substrate bias voltage ($V_s$) was employed from $V_s=0 V$ to $V_s=400 V$. The information of optical properties was investigated by photoluminescence and transmitance. Chemical bondings of a-C:H have been explored from FT-IR and Raman spectroscopy. The thickness and relative hydrogen content of the films were measured by Rutherford backscattering spectroscopy (RBS) and elastic recoil detection (ERD) technigue. The growth rate of a-C:H film was decreased with the increase of $V_s$, but the hydrogen content of the film was increased with the increase of $V_s$. The a-C:H films deposited at the lowest $V_s$ contain the smallest amount of hydrogen with most of C-H bonds in the of $CH_2$ configuration, whereas the films produced at higher $V_s$ reveal dominant the $CH_3$ bonding structure. The emission of white photoluminescence from the films were observed even with naked eyes at room temperature and the PL intensity of the film has the maximum value at $V_s$=200 V. With $V_s$ lower than 200 V, the PL intensity of the film increased with V, but for V, higher than 200 V, the PL intensity decreased with the increase of $V_s$. The peak energy of the PL spectra slightly shifted to the higher energy with the increase of $V_s$. The optical bandgap of the film, determined by optical transmittance, was increased from 1.5 eV at $V_s$=0V to 2.3 eV at $V_s$=400 V. But there were no obvious relations between the PL peak and the optical gap which were measured by Tauc process.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.9
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• pp.1013-1019
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• 2007

Electronic wastes have increased tremendously. However, any reliable treatment methodologies have rarely been established. Electronic wastes have posed serious disposal problem due to their physico-chemical stability. This paper investigated the application possibility of pyrolysis for the purpose of recycling the p-CCL(phenol based Copper Clad Laminate). Thermogravimetric analysis(TGA) was used to investigate the thermal decomposition pattern of p-CCL. We elucidated the characteristics of pyrolysis by-products at operating temperatures of 280, 350 and $600^{\circ}C$. GC/MS and FT-IR were used to characterize the liquid by-products along with general characterization methods such as Ultimate Analysis, Proximate Analysis and Heating Value, whereas general characterization methods were only introduced for the solid by-products. At a heating rate of $5^{\circ}C$/min, TGA curves exhibited three decomposition stages: (1) low-temperature decomposition region$(<280^{\circ}C)$, (2) medium temperature region$(280\sim350^{\circ}C)$ and (3) high-temperature region$(>350^{\circ}C)$. The major compounds of liquid by-products at low- and medium-temperatures were accounted for by water and phenol, whereas branched phenols and furans were major compounds at high-temperatures. As the temperature increases, volatile quantities decreased but the fixed carbon increased. High heating values of solid by-products($7,400\sim7,600$ kcal/kg) would suggest that the solid by-products could be applicable as fuel. In addition, high fixed carbon but low ash content of the solid by-products offered an implication that they are capable of being upgradable for adsorbent after applying appropriate activating process.

• The Korean Journal of Nuclear Medicine Technology
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• v.20 no.1
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• pp.37-41
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• 2016

Purpose The importance of quality control by the error to a minimum, which for the purpose of enhancing the reliability of the examination is not be emphasized excess. Currently, most nuclear medicine laboratory are conducting the internal and external quality control, and they are applying the Levey-Jennings or Westgard Multi-Rules by using the commercialized quality control materials. The reliability of the nuclear medicine blood test which affects the diagnosis of patients and the treatment policy is being secured through this quality control activity. Therefore, researchers will evaluate the utility of the statistic quality control using the population distribution of the nuclear medicine blood test conducted targeting the checkup examinees by the additional technique of the reliability improvement. Materials and Methods A statistic analysis was performed about 12 items of the nuclear medicine blood test targeting 41,341 peoples who used the health screening and promotion center in Asan Medical Center from January, 2014 to December, 2014. The results of 12 items of the nuclear medicine blood test was divided into the monthly percentage of three groups: within reference values, over reference, and under reference to analyze the average value of the population distribution, standard deviation, and standard deviation index (SDI). Results The standard deviation of the population distribution mostly showed a result within ${\pm}2SD$ in all groups. However, When the standard deviation of the population distribution represented a result over ${\pm}2SD$, it was confirmed SDI was showing a result of SDI > -2 or SDI > 2. As a result of analyzing the population distribution of 12 items(AFP, CEA, CA19-9, CA125, PSA, TSH, FT4, Anti-Tg-Ab, Anti-TPO-Ab, Calcitonin, 25-OH-VitD3, Insulin) of the nuclear medicine blood part basic test, when SDI of the monthly percentage which deviated from the reference values was over ${\pm}2.0$, CA19-9 September was 2.2, Anti-Tg-Ab may was 2.2, Insulin January was 2.3, Insulin March was 2.4. It was confirmed these cases were attributed to the abnormality of the test reagent (maximum combination rate of isotope reagent declined) and the decline of the test response time. Conclusion The population distribution includes the entire attribute which becomes the study object. It is expected the statistic quality management using the population distribution which was conducted targeting the checkup examinees by dividing into three groups: within reference values, over reference, and under reference by means of this characteristics will be able to play a role of complementing the internal quality control program which is being carried out in the laboratory.

• The Journal of Korean Society for School & Community Health Education
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• v.10 no.1
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• pp.87-104
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• 2009

Objective: In this study, the dental health care knowledge, dental health behaviors and dental health status of elementary school students were compared and analyzed in the cases of their schools having dental health care center or not one. Methods: The target groups were 167 students of A school (experimental group) where pit-and-fissure sealants, fluoride mouthrinsing, and fluoride gel application were carried out with all grades of students by school dental health care center and 158 students of B school (control group) where fluoride mouthrinsing, for all grades students and pit-and-fissure sealants for the first grade students are carried out but have no the school dental health care center. Results: This study was carried out through the answer sheets and recordings of dental inspection. The findings of this study are as follows: 1. The dental health care knowledge was compared and the results showed that on average 14.2$\pm$2.1 in experimental group and 14.0$\pm$1.9 in the control group were no significantly different (p>0.05). 2. The dental health behaviors were compared and the results showed that the experimental group was significantly different(p<0.05) in terms of the number of times of dental brushing a day, the method of tooth brushing, the time of tooth brushing, the experience of tooth brushing with fluorine, the kinds of snacks and tooth brushing in school after lunch. But there was no significant difference(p>0.05) in the time of tooth brushing and the tooth brushing after eating snacks. 3. The DMF rate was compared and the results showed the significantly difference between the average experimental group and 53.8$\pm$5.0 in the control group(p<0.05). 4. The DMFT index was compared and the results showed the significantly difference between the average 0.6$\pm$2 in the experimental group and 1.4$\pm$1.6 in the control group(p<0.05). 5. The DMFI rate was compared and the results showed the significantly difference between the average 4.2$\pm$8.3 in the experimental group and 9.5$\pm$11.0 in the control group. (p<0.05). 6. The DT rate were compared and the results showed the significantly difference between the average 10.2$\pm$29.5 in the experimental group and 32.4$\pm$44.0 in the control group(p<0.05). 7. The FT rate were compared and the results showed the significantly difference between the average 88.5$\pm$31.0 in the experimental group and 67.5$\pm$44.0 in the control group(p<0.05). Conclusions: Based on the results, above there was no significant difference in dental health care knowledge between both the experimental and the control group. But we discovered that the experimental group is better than the other one in dental health care behaviors and dental health status. Therefore, we could conclude that the school dental health care center efficiently carried out the dental care and treatment. As school dental health care centers did not work out efficiently in terms of their educating on the dental health acre knowledge, the related programs to be developed and supported.

• Journal of the Korean Wood Science and Technology
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• v.40 no.3
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• pp.194-203
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• 2012

1-Ethyl-3-methylimidazolium acetate known as efficient biomass pretreatment reagent was used for the extraction of lignin from rigida pine wood (pitch pine), which was called to ionic liquid lignin (ILL), and chemical structural features of ILL were compared with the corresponding milled wood lignin (MWL). The amounts of phenolic hydroxyl groups (Phe-OH) was determined to 10.0% for ILL and 7.2% for MWL, respectively, where those of methoxyl groups (OMe) were 4.9% for ILL and 11.0% for MWL, respectively. The weight average molecular weight (Mw) of ILL (3,995) were determined to ca. 1/2 of that of MWL (8,438) and polydispersity index (PDI: Mw/Mn) suggested that the lignin fragments were more uniform in the ILL (PDI 1.36) than in the MWL (PDI 2.64). The temperature (Tm) corresponding to maximum decomposition rate (Vm) of ILL ($306.6^{\circ}C$) was ca. $35^{\circ}C$ lower than that of MWL ($341.9^{\circ}C$), suggesting that ILL was thermally unstable than MWL, as evidence from the lower Tm for ILL. Moreover, the structural characteristics of ILL and MWL were confirmed by spectroscopic analyses (FT-IR and $^{13}C$-NMR), and these results indicated ionic liquid (1-ethyl-3-methylimidazolium acetate) was chemically or physically bound to ILL.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.24.1-24.1
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• 2009

Tantalum carbo-nitride($T_aC_xN_y$) films were deposited with chemical vapor deposition(CVD) using tert-butylimido tris-diethylamido tantalum (TBTDET, $^tBu-N=Ta-(NEt_2)_3$, $Et=C_2H_5$, $^tBu=C(CH_3)_3$) between $350^{\circ}C$ and $600^{\circ}C$ with argon as a carrier gas. Fourier transform infrared (FT-IR)spectroscopy was used to study the thermal decomposition behavior of TBTDET in the gas phase. When the temperature was increased, C-H and C-N bonding of TBTDET disappeared and the peaks of ethylene appeared above $450^{\circ}C$ in the gas phase. The growth rate and film density of $T_aC_xN_y$ film were in the range of 0.1nm/min to 1.30nm/min and of $8.92g/cm^3$ to $10.6g/cm^3$ depending on the deposition temperature. $T_aC_xN_y$ films deposited below $400^{\circ}C$ were amorphous and became polycrystal line above $500^{\circ}C$. It was confirmed that the $T_aC_xN_y$ film was a mixture of TaC, graphite, $Ta_3N_5$, TaN, and $Ta_2O_5$ phases and the oxide phase was formed from the post deposition oxygen uptake. With the increase of the deposition temperature, the TaN phase was increased over TaC and $Ta_3N_5$ and crystallinity, work function, conductivity and density of the film were increased. Also the oxygen uptake was decreased due to the increase of the film density. With the increase of the TaC phase in $T_aC_xN_y$ film, the work function was decreased to 4.25eV and with the increase of the TaN phase in $T_aC_xN_y$ film,it was increased to 4.48eV.

• Applied Biological Chemistry
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• v.32 no.4
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• pp.350-356
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• 1989

The determinabilities of several lignan compounds by capillary-GC (F1D) were studied. The lignan compounds used were deoxyschizandrin, gomisin N, schizandrin, wuweizisu C, gomisin A, angeloylgomisin H and tigloylgomisin H which were isolated from fruits of Schisandra chinensis BAILLON and identified with GC/MS(EI, 70eV), 1H-NMR(300MHz) and IR. The GC column used was SPB-1 fused silica capillary$(0.25mm\;ID{\times}30m,\;Supelco)$, and the column oven temperature was programmed from $200^{\circ}C$ to $300^{\circ}C$ at the rate of $4^{\circ}C$ per minute. The linearities between concentration and FID response were maintained in $2{\sim}500ppm$ of deoxyschizandrin and wuweizisu C and in $5{\sim}500ppm$ of gomisin N, schizandrin, gomisin A, angeloylgomisin H and tigloylgomisin H. The contents of lignan compounds in fruits of S. chinensis BAILLON produced at Moo-ju area were analyzed by the GC method: the values obtained of schizandrin and gomisin N were 6.5 and 5.9mg/g respectively, and those of gomisin A, wuweizisu C, angeloylgomisin H, deoxyschizandrin and tigloylgomisin H were $0.5{\sim}1.6mg/g$.

• The Plant Pathology Journal
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• v.33 no.5
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• pp.499-507
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• 2017

In an attempt to develop a biological control agent against mycotoxigenic Fusarium species, we isolated Bacillus amyloliquefaciens strain DA12 from soil and explored its antimicrobial activities. DA12 was active against the growth of mycotoxigenic F. asiaticum, F. graminearum, F. proliferatum, and F. verticillioides both in vitro and in planta (maize). Further screening using dual culture extended the activity range of strain DA12 against other fungal pathogens including Botrytis cinerea, Colletotrichum coccodes, Endothia parasitica, Fusarium oxysporum, Raffaelea quercus-mongolicae, and Rhizoctonia solani. The butanol extract of the culture filtrate of B. amyloliquefaciens DA12 highly inhibited the germination of F. graminearum macroconidia with inhibition rate 83% at a concentration of $31.3{\mu}g/ml$ and 100% at a concentration of $250{\mu}g/ml$. The antifungal metabolite from the butanol extract was identified as iturin A by thin layer chromatography-bioautography. In addition, volatile organic compounds produced by DA12 were able to inhibit mycelial growth of various phytopathogenic fungi. The volatile compounds were identified as 2-heptanone, 5-methyl heptanone and 6-methyl heptanone by gas chromatography-mass spectrometry (GC-MS) analysis. These results indicate that the antagonistic activity of Bacillus amyloliquefaciens DA12 was attributable to iturin A and volatile heptanones, and the strain could be used as a biocontrol agent to reduce the development of Fusarium diseases and mycotoxin contamination of crops.

• Korean Journal of Materials Research
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• v.24 no.12
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• pp.671-676
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• 2014

It is known that bones get damaged by accidents and aging. Since the discovery of Bioglass, various kinds of ceramics have been also found to bond to living bone; some of these ceramics are already being clinically used as bone-repairing materials. In the present study, antibacterial calcium silicate gel ($Ag-30CaO{\cdot}70SiO_2$ gel) was prepared by sol-gel method in order to control the microstructure, which is related to the dissolution rate and induction period of apatite formation in body environment. In addition, biological $Ag-30CaO{\cdot}70SiO_2$ is tested. This was done to impart antimicrobial activity to the $30CaO{\cdot}70SiO_2$. Ag ion was added during sol-gel synthesis to replace the $H_2O$ added during the making of the $30CaO{\cdot}70SiO_2$ gel, which has silver solutions of various concentration. After the sol-gel process, 1N-$HNO_3$ solution was used to wash the gel when synthesizing the gel, in order to maintain the porous structure and remove PEG, water soluble polymers. Then, the apatite forming ability of the sol-gel derived CaO-$SiO_2$ gels was investigated using simulated body fluid (SBF), which had almost the same ion concentration as that of human blood plasma. The gels were analyzed by FT-IR spectroscopy, SEM observation, XRD, and fluorescent microscopy. The apatite was successfully created even after washing the gel; apatite is present in an amorphous state, and was found to affect the concentration of the Ag ion in cells in MC3T3 live & dead assay results. From these results, it is suggested that a good material that can be used to repair defects of nature bone is $Ag-30CaO{\cdot}70SiO_2$ gel.