• Proceedings of the Korean Vacuum Society Conference
• /
• 2011.08a
• /
• pp.119-119
• /
• 2011

This study examined the synthesis of large area graphene and the change of its characteristics depending on the ratio of CH4/H2 by using the thermal CVD methods and performed the experiments to control the electron-hole conduction and Dirac-point of graphene by using chemical doping methods. Firstly, with regard to the characteristics of the large area graphene depending on the ratio of CH4/H2, hydrophobic characteristics of the graphene changed to hydrophilic characteristics as the ratio of CH4/H2 reduces. The angle of contact also increased to 78$^{\circ}$ from 58$^{\circ}$. According to the results of Raman spectroscopy showing the degree of defect, the ratio of I(D)/I(G) increases to 0.42% from 0.25% and the surface resistance also increased to 950 ${\Omega}$ from 750 ${\Omega}$/sq. As for the graphene synthesis at the high temperature of 1,000$^{\circ}$ by using CH4/H2 in a Cu-Foil, the possibility of graphene formation was determined as a function of the ratio of H2 included in the fixed quantity of CH4 as per specifications of every equipment. It was observed that the excessive amount of H2 prevented graphene from forming, as extra H-atoms and molecules activated the reaction to C-bond of graphene. Secondly, in the experiment for the electron-hole conduction and the Dirac-point of graphene using the chemical doping method, the shift of Dirac-point and the change in the electron-hole conduction were observed for both the N-type (PEI) and the P-type (Diazonium) dopings. The ID-VG results show that, for the N-type (PEI) doped graphene, Dirac-point shifted to the left (-voltage direction) by 90V at an hour and by 130 V at 2 hours respectively, compared to the pristine graphene. Carrier mobility was also reduced by 1,600 cm2/Vs (1 hour) and 1,100 cm2/Vs (2 hours), compared to the maximum hole mobility of the pristine graphene.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.6 no.2
• /
• pp.127-139
• /
• 2004

Agricultural meteorology has advanced during the last 100 years from a descriptive to a quantitative science using physical and biological principles. The agricultural community is becoming more aware that using climate and weather information will improve their profitability and this will no doubt increase the demand for agrometeorological services. Hence it is timely that the needs and perspectives for agrometeorology in the 21$^{21}$ Century are grouped under two major headings: agrometeorological services for agricultural production and agrometeorological support systems for such services. Emphasis must be placed on the components of such support systems comprising of data, research, policies and training/education/extension. As Monteith (2000) mentioned, food supplies ultimately depend upon the skill with which farmers ran exploit the potential of good weather and minimize the impact of bad weather. Recent developments in instrumentation, data management systems, climate prediction, crop modelling, dissemination of agrometeorological information etc., provide agrometeorologists the tools necessary help the farmers improve such skills. The future for operational applications of agricultural meteorology appears bright and such applications could contribute substantially to promote sustainable agriculture and alleviate poverty.

• Journal of Pharmaceutical Investigation
• /
• v.40 no.2
• /
• pp.125-131
• /
• 2010

A bioequivalence study of LANIDIEM$^{(R)}$ tablet 4 mg (Samil. Co., Ltd.) to Vaxar$^{(R)}$ tablet 4 mg (GlaxoSmithKline Co., Ltd.) was conducted according to the guidelines of Korea Food and Drug Administration (KFDA). Forty healthy male Korean volunteers were enrolled in the study and thirty six volunteers completed the study according to the protocol. Thirty six volunteers received each medicine at the lacidipine dose of 4 mg in a $2{\times}2$ crossover study. There was one week wash-out period between the doses. Plasma concentrations of lacidipine were monitored by a high performance liquid chromatography - tandem mass spectrometry (LC-MS/MS) for over a period of 24 hours after drug administration. $AUC_t$ (the area under the plasma concentration-time curve from time zero to 24 hr) was calculated by the linear trapezoidal rule method. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed $AUC_t$ and $C_{max}$. No significant sequence effect was found for all of the bioavailability parameters indicating that the crossover design was properly performed. The 90% confidence intervals of the $AUC_t$ ratio and the $C_{max}$ ratio for LANIDIEM$^{(R)}$/Vaxar$^{(R)}$ were log 0.8102~log 1.0417 and log 0.8493~log 1.1439, respectively. These values were within the acceptable bioequivalence intervals of log 0.80~log 1.25. Thus, our study demonstrated the bioequivalence of LANIDIEM$^{(R)}$ tablet 4 mg and Vaxar$^{(R)}$ tablet 4 mg with respect to the rate and extent of absorption.

• Korean Journal of Community Nutrition
• /
• v.12 no.3
• /
• pp.344-351
• /
• 2007

The purposes of this study were to analyze the consumer inclination to convenience towards HMR in order to verify the structural correlation of the actual state of consumption, and to analyze consequently, the direct or indirect effects among 'frequency of using,' 'preference', 'satisfaction', and 'intention to repurchase'. The subjects were adults in their twenties or older who had used HMRs and lived in Seoul and Gyeonggi Province in Korea. Random sampling of 550 subjects, who were distributed a questionnaire from March 12 to 30, 2005. A total of 451 questionnaires were returned (the return rates were 82%). The main results of this study were as follows : Regarding the types of HMR, 'Ready to eat' had higher preference (3.31), satisfaction (3.33) and 'intention to purchase it again' (3.38) than those of 'Ready to heat' and 'Ready to end-cook.' Consumer inclination to convenience towards HMR was analyzed in order to verify the structural correlation of the actual state of consumption, and consequently, the direct or indirect effects among 'frequency of using,' 'preference', 'satisfaction', and 'intention to repurchase' were analyzed. The gross effect of 'frequency of using' on 'intention to repurchase' was 0.435, the gross effect of preference on 'intention to purchase it again' was 0.659, and the gross effect of satisfaction on 'intention to purchase it again' was 0.772 for 'Ready to eat.' The gross effect of 'frequency of using' on 'intention to repurchase' was 0.448, the gross effect of preference on 'intention to repurchase' was 0.556, and the gross effect of satisfaction on 'intention to repurchase' was 0.654 for 'Ready to heat.' The gross effect of 'frequency of using' on 'intention to repurchase' was 0.432, the gross effect of preference on 'intention to repurchase' was 0.494, and the gross effect of satisfaction on 'intention to repurchase' was 0.608 for 'Ready to end-cook.' To summerize the above results, there was a difference of the structural correlation among component concepts of the actual state of consuming according to the criteria of HMR. Thus, it implied that differentiated sales strategies were needed according to the criteria of HMR.

• Economic and Environmental Geology
• /
• v.30 no.3
• /
• pp.209-222
• /
• 1997

The Hoenam area, up the Taecheong lake, composed mainly of low grade coal-bearing metapelites within the Ogcheon Supergroup. These coal formations are developed discontinuously several hundred meters and swelling from 10 to 300 cm along the host metapelites. Although the formations have been mined for coal, but already mined out, and the formations were higher content (mean value of 42 samples) of environmental toxic elements as As (13 ppm). Ba (1.81 wt. %), Cd (2 ppm), Cr (188 ppm), Cu (87 ppm), Mo (214 ppm), Pb (25 ppm), Sb (3 ppm), Se (12 ppm), U (55 ppm), V (2124 ppm) and Zn (234 ppm) than the host metapelites and the NASC. The Al, Ti, Mg, K and Na contents in stream sediments derived from the Hando and Bugook mine area were highly concentrations than the samples from the Samseongjeil mine area. The mean value (wt. %) of Fe (10.07), Mn (0.15), Ca (0.84), P (0.18) and Ba (0.77) influenced by the Samseongjeil mine were higher than the other mine drainage sediments. The mean content (ppm) of environmental toxic elements in drainage sediments from the Samseongjeil mine were taken As (2083), Cu (447), Mo (202), Ni (720), Pb (42), U (250), V (1070) and Zn (2632), which are extremely high concentrations against NASC and EPA. Characteristics of elemental behavior and dispersion of the all toxic elements are the same as increased with increasing U, V, and Cu. Rare earth elements in the sediments are enriched with LREE (La, Ce and Nd) from the drainage on strong concentration of toxic elements. The pH of stream water is neutral, but pH of the sediments ranged from 4.92 to 6.93 (mean 6.22), those are slightly acid in the Hando mine area. Major elements in the host rocks at the Hoenam area are mostly depleted especially Ca, excepting Ti and Ba, normalized with NASC. The sediments were highly enriched of Ti, Fe, Mg, Mn and Ba, but depleted of Al, K, Ca, Na and P on the basis of host rocks and NASC. Minor and environmental toxic elements in the host rocks were strongly enriched all elements (As, Cd, Mo, Se, D, V and Zn), excepting Co, Ni and Sr. Enrichment index (mean value) about toxic elements (As, Cr, Cu, Fe, Ni, Pb and Zn) of the sediments in this area have taken 41.35 (Hando mine drainage; 2.73, Samseongjeil mine drainage; 113.14 and Bugook mine drainage; 8.19), those are seriously contaminated by environmental toxic elements.

• Economic and Environmental Geology
• /
• v.53 no.4
• /
• pp.397-411
• /
• 2020

The Cretaceous Yucheon Group is volcano-sedimentary successions that are formed by volcanic activities of the Gyeongsang Volcanic Arc. Lack of the detailed field researches on the Yucheon Group results in poor understanding of the formation time and the tempo-spatial development of the volcanic arc. Also, this causes difficulties to reconstruct the depositional history from the Sindong and Hayang groups to the Yucheon Group. In this study, we conducted field research targeting to the interface between topmost part of the Hayang Group and the lowermost part of the Yucheon Group from Hyeonpoong to Bugok areas. We also identified depositional timing of the lowermost part of the Yucheon Group using SHRIMP U-Pb zircon age dating. This Yucheon Group is composed of tuff and lapilli tuff, conformably overlying the Jindong Formation. The results of SHRIMP U-Pb zircon age are 97 to 96 Ma, indicating cessation of deposition of the Hayang Group at 97 to 96 Ma by input of pyroclastic materials into the Jinju Subbasin during the explosive volcanic eruptions from the Gyeongsang Volcanic Arc. In comparison with field researches and results of LA-ICP-MS zircon U-Pb age dating (88-85 Ma) of the lowermost part of the Yucheon Group in Gyeongju areas, the volcanic activities that formed Yucheon Group and their influence ranges varied tempo-spatially. This is probably due to distance difference from the volcanic arc or establishment of the paleo-drainage system from the Gyeongsang Volcanic Arc to nearby lowlands.

• Journal of Food Hygiene and Safety
• /
• v.22 no.2
• /
• pp.77-81
• /
• 2007

Antimicrobial activity of both fresh Prunus mume and Prunus mume liqueur byproduct (PLB), generated after producing Prunus mume liqueur were examined against various pathogeinc bacteria such as Listeria monocytogenes Scott A, Listeria monocytogenes ATCC 19115, Bacillus cereus KCCM 11341, Staphylococcus aureus KCCM 12255, Pseudomonas fluorescens ATCC 21541, Escherichia coli O157:H7, Salmonella Typhimurium ATCC 14028, and Shigella sonnei. PLB showed strong antibacterial effects against tested pathogenic bacteria.L. monocytogenes ATCC 19115, B. cereus KCCM 11341, S. sonnei, and E. coli O157:H7 were not detected in trytpic soy broth containing 1% of prunus mume or PLB after 24-hour incubation at $37^{\circ}C$, respectively. Prunus mume showed higher antimicrobial activities than that of PLB against tested pathogens.

• Korean Journal of Ecology and Environment
• /
• v.46 no.1
• /
• pp.86-93
• /
• 2013

We monitored 32 wetlands in order to investigate the influence of aquatic plants on zooplankton density and diversity in the littoral zone in Gyeongsangnam-do from May to June in 2011. A total of 65 zooplankton species were identified in the study sites. Among them, the diversity of epiphytic zooplankton were higher (40 species) than planktonic zooplankton. Littoral zones of all wetlands were covered by various aquatic plants, and influenced the epiphytic zooplankton assemblages. Based on the data from $1{\times}1$ (m) quadrat sampling, epiphytic and planktonic rotifer density showed no significant relationships with macrophyte cover. However, the epiphytic cladocerans density significantly increased under high aquatic plant cover ($r^2=0.39$, p<0.05, n=32). Types of aquatic plants strongly influenced epiphytic zooplankton density. Upo and Jangcheok are locations which have well developed Phragmites communis and Ceratophyllum demersum communities in the littoral zone, and a higher density of epiphytic zooplankton was recorded on the surface of C. demersum. Especially, rotifers such as Lepadella, Monostyla and Testudinella showed obvious differences (One-way ANOVA, p<0.05 for all three species). This result suggests that epiphytic zooplankton have a substrate preference for larger surface areas, likely for adherence, on C. dimersum. In conclusion, the complex structure of the littoral plant community is expected to provide diverse refuge and microhabitats to epiphytic zooplankton.

• Korean Journal of Food Science and Technology
• /
• v.40 no.5
• /
• pp.562-567
• /
• 2008

The primary objective of this study was to select a probiotic starter for cheonggukjang using 60 strains isolated from rice straw. Among isolated strains, only 8 strains including strain B-59 evidenced proteolytic, amylolytic and soybean activity. These 8 strains were all gram-positive, spore-forming rods. The B-59 strain evidenced antimicrobial activity against Staphylococcus aureus, Listeria monocytogenes, Pseudomonas fluorescens, and Vibrio parahaemolyticus. The antimicrobial activity of isolated B-59 was verified by its ability to inhibit the growth of S. aureus, L. monocytogenes, P. fluorescens, and V. parahaemolyticus. The selected B-59 strain was indentified as Bacillus licheniformis, as shown by a result of 99.0% homology upon API kit analysis. The selected B-59 strain also displayed viability in pH 2.5 artificial gastric juice, artificial bile acid, NaCl (2, 4, 8, 16, 32%), and ethanol (4, 8, 16, 32%). The antioxidative activity of the strain B-59 culture was assessed via a DPPH free radical scavenging activity assay. The activity increased with an increasing in the fermentation time of strain B-59 for 20 hours.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.4
• /
• pp.464-473
• /
• 2016

The air temperatures of the coast and inland are rising due to an increase in carbon dioxide emissions and abnormal climate phenomena caused by global warming, El Nino, La Nina and so on. The sea levels of the Earth are rising by approximately 2.0 mm per year (global average value) due to the thermal expansion of sea water, melting of glaciers and other causes by global warming. On the other hand, when it comes to designing a hydraulic structure or coastal hydraulic structure, the standard of the design water level is decided by analyzing four largeness tide values and a harmonic constant with the observed tidal water level or simulating numerical model. Therefore, the design tidal water level needs to consider an increasing speed of the seawater level, which corresponds to the design frequency. In the present study, the observed tidal water levels targeting 46 tidal stations operated by the Korea Hydrographic and Oceanographic Administration (KHOA) from the beginning of observations to 2015 per hour were collected. The variation of the monthly and yearly and increasing ratio were performed and divided into 7 seas, such as east and west part of the Southern Sea, south part and middle of the East Sea, south part and middle of the Western Sea, and Jeju Sea. The current study could be used to determine the cause of local seawater rises and reflect the design tidal water level as basic data.