• KSBB Journal
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• v.22 no.5
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• pp.345-350
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• 2007

Phosphosugars are found in all living organisms and are commercially valuable compounds with possible applications in the development of a wide range of specialty chemicals and medicines. In carbohydrate metabolism, fructose 6-phosphate (F6P) is an essential intermediate formed by phosphorylation of 6' position of fructose in glycolysis, gluconeogenesis, pentose phosphate pathway and Calvin cycle. In glycolysis, F6P lies within the glycolysis metabolic pathway and is produced by isomerisation of glucose 6-phosphate. For large-scale production, F6P could be produced from starch using many enzymes such as pullulanase, starch phosphorylase, isomerase and mutase. In enzymatic reactions carried out at high temperatures, the solubility of starch is increased and microbial contamination is minimized. Thus, thermophile-derived enzymes are preferred over mesophile-derived enzymes for industrial applications using starch. Recently, we reported the production of glucose 1-phosphate (G1P) from starch by Thermus caldophilus GK24 enzymes. Here we report the production of F6P from starch through three steps; from starch to glucose 1-phosphate (glucan phosphorylase, GP), then glucose 6-phosphate (phosphoglucomutase, GM) and then F6P (phosphoglucoisomerase, GI). Using 200 L of 1.2% soluble starch solution in potassium phosphate buffer, 1,253 g of G1P were produced. Then, 30% yields of F6P were attained at the optimum reaction conditions of GM : G1 (1 : 2.3), 63.5$^{\circ}C$, and pH 6.85. The optimum conditions were found by response surface methodology and the theoretical values were confirmed by the experiments. The optimum starch concentrations were 20 g/L under the given conditions.

• Journal of the Korean Geographical Society
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• v.49 no.1
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• pp.45-56
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• 2014

Data composite methods have been typically applied to satellite-based vegetation index(VI) data to continuously acquire vegetation greenness over the land surface. Data composites are useful for construction of long-term archives of vegetation indices by minimizing missing data or contamination from noise. In addition, if multi-sensor vegetation indices that are acquired during the same composite periods are used interchangeably, data stability and continuity may be significantly enhanced. This study evaluated the influences of sensor geometry on MODIS vegetation indices and investigated data compatibility of two difference vegetation indices, the Normalized Difference Vegetation Index(NDVI) and the Enhanced Vegetation Index(EVI), for potential improvement of long-term data construction. Relationships between NDVI and EVI turned out statistically significant with variations among vegetation covers. Due to their curvilinear relationships, NDVI became saturated and leveled off as EVI reached high ranges. Correlation coefficients between Terra- and Aqua-based vegetation indices ranged from 0.747 to 0.963 for EVI, and from 0.641 to 0.880 for NDVI, showing better compatibility for EVI compared to NDVI. In-depth analyses of VI outliers that deviated from regression equations constructed from the two different sensors remain as a future study to improve their compatibility.

• Progress in Medical Physics
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• v.8 no.2
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• pp.45-57
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• 1997

It is mandatory to measure accurately the dose distribution and the total absorbed dose of fast neutron for putting it to the clinical use. At present the methods of measurement of fast neutron are proposed largely by American Associations of Physicists in Medicine, European Clinical Neutron Dosimetry Group, and International Commission on Radiation Units and Measurements. The complexity of measurement, however, induces the methodological differences between them. In our study, therefore, we tried to establish a unique technique of measurement by means of measuring the emitted doses and the dose distribution of fast neutron beam from neutron therapy machine, and to invent a standard method of measurement adequate to our situation. For measuring the absorbed doses and the dose distribution of fast neutron beam, we used IC-17 and IC-18 ion chambers manufactured by A-150 plastic(tissue-equivalent material), IC-17M ion chamber manufactured by magnesium, TE gas and Ar gas, and RDM 2A electrometer. The magnitude of gamma-contamination intermingled with fast neutron beam was about 13％ at 5cm depth of standard irradiated field, and increased as the depth was increased. At the central axis the maximum dose depth and 50％ dose depth were 1.32cm and 14.8cm, respectively. The surface dose rate was 41.6-54.1％ throughout the entire irradiated fields and increased as the irradiated fields were increased. Beam profile was that the horn effect of about 7.5％ appeared at 2.5cm depth and the flattest at 10cm depth.

• Geophysics and Geophysical Exploration
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• v.19 no.1
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• pp.37-44
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• 2016

$CO_2$-EOR (Carbon Dioxide-Enhanced Oil Recovery), one of the enhanced oil recovery methods, helps to not only enhance the production of oil, but also store carbon dioxide in underground. However, if micro fractures occur when during the injection of $CO_2$, it is difficult to make permanent storage of $CO_2$ in reservoir and can cause contamination of groundwater and soil. Therefore, in this study, we performed microseismic monitoring to investigate the occurrence of fractures during the $CO_2$ injection at the Meruap oil reservoir, Indonesia. To pick the first arrivals of microseismic events, Improved MER (Modified Energy Ratio) method was used. After picking the first arrivals, hodogram analysis was carried out by using the data recorded at three component geophones to calculate the back azimuth of events. Finally, locations of microseismic events were decided by using the results of first arrival picking and hodogram analysis. Estimated locations showed that all microseismic events were occurred at surface and any fracture did not occur around the reservoir. Moreover, by analyzing noise characteristic, we confirmed that almost of picked first arrivals were due to the repetitive mechanical noise.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.121-121
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• 2004

The groundwater in the Pocheon area occurs from both a fractured bedrock aquifer in igneous and metamorphic rocks and an alluvial aquifer with a thickness of <50 m, and forms a major source of domestic and agricultural water supply. In this study, we performed a hydrogeochemical study in order to identify the control of geochemical processes on groundwater quality. For this study, groundwater level and physicochemical parameters (EC, Eh, pH, alkalinity) were monitored once a month from a total of 150 groundwater wells between June 2003 to August 2004. A total of 153 water samples (13 surface water, 66 alluvial groundwater, 74 bedrock groundwater) were also collected and analyzed in February 2004. Groundwater chemistry in the study area is very complex, depending on a number of major factors such as geology, degree of chemical weathering, and quality of recharge water. Hydrochemical reactions such as the leaching of surficial and near-solace soil salts, dissolution of calcite, cation exchange, and weathering of silicate minerals are proposed to explain the chemistry of natural groundwater. Alluvial groundwaters locally have very high TDS concentrations, which are characterized by their chloride(nitrate)-sulfate-bicabonate facies and low Na/Cl ratio. Their grondwater levels are highly fluctuated according to rainfall event. We suggest that high nitrate content and salinity in such alluvial groundwaters originates from the local recharge of sewage effluents and/or fertilizers. Likewise, high concentrations of nitrate were also locally observed in some bedrock groundwaters, suggesting their effect of anthropogenic contamination. This is possibly due to the bypass flow taking place through macropores. Tile degree of the weathering of silicate minerals seems to be a major control of the distribution of major cations (sodium, calcium, magnesium, potassium) in bedrock groundwaters, which show a general increase with increasing depth of wells. Thermodynamic interpretation of groundwater chemistry shows that the groundwater in the study area is in chemical equilibrium with kaolinite and Na-montmorillonite, which indicates that weathering of plagioclase to those minerals is a major control of hydrochemistry of bedrock groundwater. The interpretation of the molar ratios among major ions, as well as the mass balance calculation, also indicates the role of both dissolution/precipitation of calcite and Ca-Na cationic exchange as bedrock groundwaters evolves progressively.

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.2
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• pp.152-160
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• 1997

In order to monitor the content of heavy metals of soil and vegetable in the plastic film house, five hundred and twenty two soil, and 147 vegetable samples grown under plastic film house were collected for the analysis of heavy metals. The average contents of Cd, Cu, Pb, Zn and As in surface soil were 0.208, 3.69, 2.49, 23.3 and 0.65mg/kg, respectively. Cu and Zn contents of the soil were higher than those values measured for upland soils in 1989, however, these contents were lower than "Countermeasure values" (Cd:4, Cu:125, Pb:300, and As:15mg/kg in soil) for soil contamination indicators described in Soil Environmental Conservation Act of Korea(1996). The contents of Cd, Cu and Zn increased with increasing years of cultivation. The contents of Cd, Cu, and Zn in soils received pig manure compost were higher than those received the poultry or barn yard manure compost. The average contents of Cd, Cu, Pb, Zn and As in fresh vegetable plants ranged from 0.015 to 0.047, 0.341 to 0.802, 0.080 to 0.356, 1.08 to 8.04 and 0.021 to 0.059mg/kg, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.5
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• pp.601-605
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• 2005

Three lines of White Leghorn (WL) chickens (IWJ, IWG and IWC) maintained at Central Avian Research Institute, Izatnagar (UP), were used for chorioallantoic membrane (CAM) and liver tumour (LT) assay. Eleven-day-old embryos of each line were partitioned into three groups and inoculated with 0.2 ml of subgroup A, subgroup C and an equal mixture of subgroup A and C Rous sarcoma virus (RSV). Subgroup virus receptor on the cell surface membrane for subgroup A is coded for by tumour virus a (tva) locus and for subgroup C by tumour virus c (tvc) locus. The random association of the genes at the tva and tvc loci in IWJ and IWC line was assessed and the $x^2$-values for phenotypic classes were found to be significant, indicating the linkage between the tva and tvc loci. The linkage value was estimated to be 0.09 on pooled sex and pooled line basis. On the basis of four subclass tumour phenotypes a 4-allele model was proposed for tva locus having $a^{s1}$, $a^{s2}$, $a^{r1}$ and $a^{r2}$ alleles and the frequencies were calculated as 0.47, 0.13, 0.13 and 0.27 for IWJ line, 0.31, 0.33, 0.14 and 0.22 for IWG line and 0.44, 0.11, 0.21 and 0.24 for IWC line, respectively. Similarly, for tvc locus the frequencies of four alleles i.e. $c^{s1}$, $c^{s2}$, $c^{r1}$ and $c^{r2}$ were calculated as 0.42, 0.20, 0.21 and 0.17 for IWJ line, 0.42, 0.17, 0.27 and 0.14 for IWG line and 0.30, 0.21, 0.16 and 0.33 for IWC line, respectively. The $x^2$-values for all classes of observations were not significant (p>0.05), indicating a good fit to the 4-allele model for the occurrence of 4-subclass tumour phenotypes for tva and tvc loci. On the basis of the 2-allele model both tva and tvc locus carries three genotypes each. But, on the basis of the 4-allele model tva and tvc locus carries 10 genotypes each. The interaction between A-resistance and C-resistance (both CAM and LT death) was ascertained by taking the 10 genotypes of tva locus and 3 genotypes of tvc locus by pooling the lines and partitioning the observations into 3 classes. The $x^2$-values for the genotypic classes of CAM (-) LT (+) and CAM (-) LT (-) phenotypes to mixed virus (A+C) infection were found to be highly significant (p<0.01), indicating increased resistance, which indicates the joint segregation of $a^r$ and $c^r$ genes, suggesting the existence of close linkage between the tva and tvc loci. Therefore, an indirect selection approach using subgroup C viruses can be employed to generate stocks resistant to subgroup A LLV, obviating contamination with the most common agent causing LL in field condition.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.11
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• pp.1660-1666
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• 2017

Objective: Burial is associated with environmental effects such as the contamination of ground or surface water with biological materials generated during the decomposition process. Therefore, bacterial communities in leachates originating from the decomposing bovine carcasses were investigated. Methods: To understand the process of bovine (Hanwoo) carcass decomposition, we simulated burial using a lab-scale reactor with a volume of $5.15m^3$. Leachate samples from 3 carcasses were collected using a peristaltic pump once a month for a period of 5 months, and bacterial communities in samples were identified by pyrosequencing of the 16S rRNA gene. Results: We obtained a total of 110,442 reads from the triplicate samples of various sampling time points (total of 15 samples), and found that the phylum Firmicutes was dominant at most sampling times. Differences in the bacterial communities at the various time points were observed among the triplicate samples. The bacterial communities sampled at 4 months showed the most different compositions. The genera Pseudomonas and Psychrobacter in the phylum Proteobacteria were dominant in all of the samples obtained after 3 months. Bacillaceae, Clostridium, and Clostridiales were found to be predominant after 4 months in the leachate from one carcass, whereas Planococcaceae was found to be a dominant in samples obtained at the first and second months from the other two carcasses. The results showed that potentially pathogenic microbes such as Clostridium derived from bovine leachate could dominate the soil environment of a burial site. Conclusion: Our results indicated that the composition of bacterial communities in leachates of a decomposing bovine shifted continuously during the experimental period, with significant changes detected after 4 months of burial.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.344-344
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• 2014

Transparent amorphous oxide semiconductors such as a In-Ga-Zn-O (a-IGZO) have advantages for large area electronic devices; e.g., uniform deposition at a large area, optical transparency, a smooth surface, and large electron mobility >10 cm2/Vs, which is more than an order of magnitude larger than that of hydrogen amorphous silicon (a-Si;H).1) Thin film transistors (TFTs) that employ amorphous oxide semiconductors such as ZnO, In-Ga-Zn-O, or Hf-In-Zn-O (HIZO) are currently subject of intensive study owing to their high potential for application in flat panel displays. The device fabrication process involves a series of thin film deposition and photolithographic patterning steps. In order to minimize contamination, the substrates usually undergo a cleaning procedure using deionized water, before and after the growth of thin films by sputtering methods. The devices structure were fabricated top-contact gate TFTs using the a-IGZO films on the plastic substrates. The channel width and length were 80 and 20 um, respectively. The source and drain electrode regions were defined by photolithography and wet etching process. The electrodes consisting of Ti(15 nm)/Al(120 nm)/Ti(15nm) trilayers were deposited by direct current sputtering. The 30 nm thickness active IGZO layer deposited by rf magnetron sputtering at room temperature. The deposition condition is as follows: a rf power 200 W, a pressure of 5 mtorr, 10% of oxygen [O2/(O2+Ar)=0.1], and room temperature. A 9-nm-thick Al2O3 layer was formed as a first, third gate insulator by ALD deposition. A 290-nm-thick SS6908 organic dielectrics formed as second gate insulator by spin-coating. The schematic structure of the IGZO TFT is top gate contact geometry device structure for typical TFTs fabricated in this study. Drain current (IDS) versus drain-source voltage (VDS) output characteristics curve of a IGZO TFTs fabricated using the 3-layer gate insulator on a plastic substrate and log(IDS)-gate voltage (VG) characteristics for typical IGZO TFTs. The TFTs device has a channel width (W) of $80{\mu}m$ and a channel length (L) of $20{\mu}m$. The IDS-VDS curves showed well-defined transistor characteristics with saturation effects at VG>-10 V and VDS>-20 V for the inkjet printing IGZO device. The carrier charge mobility was determined to be 15.18 cm^2 V-1s-1 with FET threshold voltage of -3 V and on/off current ratio 10^9.

• Journal of Wetlands Research
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• v.14 no.4
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• pp.489-502
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• 2012

Biogeochemical processes in groundwater-stream water mixing zone are recently of great interest because biodegradation and natural attenuation of aquatic contaminants may occur through the processes. The objectives of this study are to investigate the hydrologic and biogeochemical processes at the groundwater-stream water mixing zone through which surface water-driven nitrate may be naturally attenuated, and to examine the effect of the vertical flow exchange flux on biogeochemical processes using correlation analysis. To examine the direction of vertical water flow in the zone, vertical hydraulic gradients were measured at several depths using mini-piezometers. Microbial populations in soil samples of the zone were also analyzed by means of the polymerase chain reaction (PCR) and Cloning methods. In addition, partial correlations among vertical flow exchange, nitrate concentration and microbial activity was investigated to examine their mutual interaction. The results showed the significant interaction among the three parameters, resulting in natural attenuation of nitrate. This study showed an example of the biogeochemical fuction of groundwater-stream water mixing zone, which can be predictable from the examination of the interaction among microbial activities, concentration of contamination and vertical flow exchange flux. temperature show a significant difference in adjacent streambed, Also, the results shows that distribution of temperature was more affected by groundwater direction than intensity of flux.