• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.6
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• pp.718-724
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• 1999

This study was investigated the changes of the properties of matter such as the gel formation of the combined fish based on the mixed rate between the ocean jumbo squid and Alaska pollock surimi, and compared the relationships between the gel formation and water holding capacity. The changes of the gel formation based on 20 min fish grinding time and $2.5\%$ salt concentration according to the mixed rate was thought as the optimal addition limit. There was no significant function of gel product more than $20\%$ Jumbo squid meat. The more squid meat in the mixed meat could make the lower breaking stress but 7:3 rate of pollock : squid could retain breaking strain. The effect of the moisture content on mixed fish meat was studied and the drastic decrease of the gel formation and water holding capacity was indicated in $78\%$.

• Economic and Environmental Geology
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• v.22 no.3
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• pp.221-235
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• 1989

Gold-silver mineralization of the Goryeong-Waegwan area was deposited in three stages of quartz and calcite veins which fill fissures in Cretaceous sedimentary rocks of the Sindong Group. Radiometric dating indicates that mineralization is Late Cretaceous age(98 Ma) likely associated genetically with intrusion of a small biotite granite stock. Fluid inclusion and stable isotope data indicate that Au-Ag ore was deposited at temperatures between $280^{\circ}C$ and $230^{\circ}C$ from fluids with salinities between 1.7 and 8.7 equiv.wt.% NaCl. Evidence of boiling indicates pressures of <100 bars, corresponding to depths of 425 and 1,150m, respectively, assuming lithostatic and hydrostatic loads. Within ore stage I there is an apparent decrease in ${\delta}^{34}S$ values of $H_2S$ with paragenetic time, from +1.4 to -2.5 per mil. This pattern was likely achieved through progressive increases in pH and activity of oxygen accompanying boiling. Measured and calculated hydrogen and oxygen isotope values of ore-forming fluids(${\delta}D$ = -90 to -100 per mil; ${\delta}^{18}O$ = +3.9 to -11.4 per mil) indicate meteoric water dominance, approaching unex-changed meteoric water values. Au-Ag deposition is thought to be the result of cooling and dilution of a boiling fluid through mixing with less evolved meteoric waters.

• Economic and Environmental Geology
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• v.51 no.4
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• pp.323-343
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• 2018

This study defines the mineralogical, micro-textural and geochemical characteristics for the carbonate rocks and discusses the fluids that have affected the depositional environment of the Lower Makgol Formation in Seokgaejae section. Based on analysis of X-ray Diffraction (XRD), Scanning Electron Microscope-Energy Dispersive X-ray Spectrometry (SEM-EDS), Electron Probe Micro Analyzer-Wavelength Dispersive X-ray Spectrometry (EPMA-WDS) and Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS), carbonate miorofacies in the basal and the lower members of the Makgol Formation are distinguished and classified into four types. Type 1 dolomite (xenotopic interlocking texture) and Type 2 dolomite (idiotopic interlocking texture) have relatively high Mg/Ca ratio, flat REE pattern, low Fe and Mn. Extensively interlocking textures in these dolomites indicate constant supply of Mg ion from hypersaline brine. Type 3 and Type 4 dolomite (scattered and loosely-aggregated texture) have relatively moderate Mg/Ca ratio, MREE enriched pattern, low to high Fe and Mn. These partial dolomitization indicate limited supply of Mg ion under the influx of meteoric water with seawater. Also, the evidence of Fe-bearing minerals, recrystallization and relatively high Fe and Mn in Type 4 indicates the influence of secondary diagenetic fluids under suboxic conditions. Integrating geochemical data with mineralogical and micro-textural evidence, the discrepancy between the basal and the lower members of the Makgol Formation indicates different sedimentary environment. It suggest that hypersaline brine have an influence on the basal member, while mixing meteoric water with seawater have an effect on the lower member of the Makgol Formation.

• Economic and Environmental Geology
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• v.36 no.4
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• pp.257-268
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• 2003

The Cretaceous magmatism in the Gyeongsang Basin, Korea, led to the formation of two contrasting metallogenic provinces: the Haman-Gunbug-Goseong(-Changwon) (HGGC) and the Euiseong (EU). The mineralization in the HGGC metallogenic province represents copper, gold and iron of porphyry-related deposits that display close relationships in time and space with subvolcanic granitoids. Much of copper-gold-forming events in this province are consistently constrained to the period between ca. 89 and 81 Ma. The hydrothermal systems of copper-gold vein deposits in the HGGC province are associated with ore-forming fluids of high to intermediate temperature (300∼50$0^{\circ}C$) with high salinity (20∼55 equiv. wt. % NaCl). The ore-forming fluids become progressively more diluted by the incorporation of decreased quantities of magmatic water further from the nearby intrusion, suggesting significant input and fluid mixing of a meteoric water component to the magmatic fluids during the late stage of geothermal systems. In contrast, the EU metallogenic province is characterized by polymetallic vein deposits that are consistently constrained to a period of 78∼60 Ma. The geothermal systems of polymetallic vein deposits in the EU province are derived from a narrow range of intermediate temperature (200∼40$0^{\circ}C$) with relatively low salinity(1∼7 equiv. wt.% NaCl). It may represent a mixed fluid of magmatic and meteoric waters. The base-metal mineralization in the Gyeongsang Basin shows a close spatial and temporal distinction between the proximal environment derived from shallow-level granitoids in the southwestern HGGC province and the distal condition derived from volcanic environments in the northwestern EU province.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.3
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• pp.332-344
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• 1996

The vertical profiles of the natural $^{210}Po,\;^{210}Pb\;and\;^{234}Th$, activities were measured at the upper 150 m or 200 m of water column from west-east intersection in the east-southern coastal area of the Korea Peninsula during the period from 26 to 29 April 1994 to compare the removal rates (residence time) and removal processes for $^{210}Po\;and\;^{234}Th$. At the inshore stations, the $^{210}Po$ activity was generally higher in the thermocline and its under layer than in the surface mixed layer, while represented the reversed pattern at the offshore stations. However, the $^{210}Pb$ activity decreased generally with depth. Also, the activity of $^{210}Po$ relative to its parent $^{210}Pb$ was deficient in the water column above the main thermocline, but was slightly excess or close to equilibrium in the thermocline and its under layer. The vertical profiles for the activity of $^{210}Pb$ relative to its parent $^{226}Ra$ showed the reversed pattern with the vertical variation of $^{210}Po$ excess (or deficiency). The $^{234}Th$ activity was significantly lower in the surface mixed layer and thermocline than in the deeper layer. The residence time of $^{210}Po$ ranged from 1 to 4 years at the five stations except station E8 that showed yet long residence time (approximately 10 years). The long residence time at the station E8 may resulted from the thicker surface mixed layer and subsequent the vertical mixing of $^{210}Po$ which was recycled in the lower surface mixed layer compared to at the other stations. Also, the residence time of $^{210}Po$ was shorter at the inshore stations than at the offshore stations. However, the residence time of $^{234}Th$ ranged from 52 to 74 days at all station without the significant variation, was very much shorter relative to the residence time of $^{210}Po$. The correlation between the removal rate of dissolved $^{234}Th$ and the concentration of total suspended matter (TSM) was generally positive. Therefore, it seems that the major route of the removal mechanism of $^{234}Th$ from seawater in the surface mixed layer is via adsorption onto suspended particle surfaces (most likely inorganic particles) and subsequent settling to the bottom layer. Between the removal rate of dissolved $^{210}Po$ and the concentration of chlorophyll-a was positively good correlation. Consequently, most likely the removal of $^{210}Po$ may be occurred by uptake to organisms (mainly such as planktonic debris or fecal pellets) and subsequent settling.

• Food Science and Preservation
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• v.21 no.2
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• pp.193-198
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• 2014

The quality and antioxidative characteristics of drinks prepared with different mixing ratios of black garlic and Oenanthe javanica DC., BD-1 (black garlic only), BD-2 (black garlic:Oenanthe javanica DC.=2:1), BD-3 (black garlic:Oenanthe javanica DC.=1:1), and BD-4 (black garlic:Oenanthe javanica DC.=1:2), were studied. The pH increased with the increasing concentration of Oenanthe javanica DC. extract in all the tested drinks, but the sugar contents decreased. The total polyphenol contents of the drinks were 28.48 ${\mu}g/mL$ (BD-1), 41.91 ${\mu}g/mL$ (BD-2), 42.36 ${\mu}g/mL$ (BD-3), and 46.96 ${\mu}g/mL$ (BD-4). The SOD-like activity was highest for BD-4 (18.60%), followed by BD-3 (15.53%), BD-2 (12.53%), and BD-1 (10.27%). The thiobarbituric acid reactive substances (TBARS) was highest for BD-4 (52.51%), followed by BD-3 (45.70%), BD-2 (39.44%), and BD-1 (28.72%). The ferrous ion chelating activity increased with the increasing concentration of Oenanthe javanica DC extract, and BD-4 showed the best activities among all the tested drinks. The water-soluble vitamin content (vitamins B1, B2, B6, and C) of BD-4 (1197.77 ${\mu}g/mL$) was higher than those of the other drinks (BD-1, 213.02 ${\mu}g/mL$; BD-2, 477.87 ${\mu}g/mL$; BD-3, 914.72 ${\mu}g/mL$), and the vitamin C (806.21 ${\mu}g/mL$) content of the water-soluble vitamins at BD-4 was higher than those of vitamins B1 (68.04 ${\mu}g/mL$), B2 (312.51 ${\mu}g/mL$), and B6 (11.01 ${\mu}g/mL$). BD-4 showed the best score in the sensory evaluations, such as in the evaluation of the color, flavor, taste, and overall acceptability.

• Korean Journal of Ecology and Environment
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• v.48 no.3
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• pp.147-152
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• 2015

Nitrogen (N) loading from domestic, agricultural and industrial sources can lead to excessive growth of macrophytes or phytoplankton in aquatic environment. Many studies have used nitrogen stable isotope ratios to identify anthropogenic nitrogen in aquatic systems as a useful method for studying nitrogen cycle. In this study to evaluate the precision and accuracy of Kjeldahl processes, two reference materials (IAEA-NO-3, N-1) were analyzed repeatedly. Measured the ${\delta}^{15}N-NO_3$ and ${\delta}^{15}N-NH_4$ values of IAEA-NO-3 and IAEA-N-1 were $4.7{\pm}0.2$‰ and $0.4{\pm}0.3$‰, respectively, which are within recommended values of analytical uncertainties. Also, we investigated spatial patterns of ${\delta}^{15}N-NO_3$ and ${\delta}^{15}N-NH_4$ in effluent plumes from a waste water treatment plant in Han River, Korea. ${\delta}^{15}N-NO_3$ and ${\delta}^{15}N-NH_4$ values are enriched at downstream areas of water treatment plant suggesting that dissolved nitrogen in effluent plumes should be one of the main N sources in those areas. The current study clarifies the reliability of Kjeldahl analytical method and the usefulness of stable isotopic techniques to trace the contamination source of dissolved nitrogen such as nitrate and ammonia.

• The Korean Journal of Nuclear Medicine Technology
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• v.22 no.2
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• pp.97-100
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• 2018

Purpose The glomerular filtration rate (GFR) test is an important indicator of glomerular filtration and has been used to test renal function and the extent of its function. The GFR test is performed by intravenous injection of radioactive medicines made of $^{51}Cr$-EDTA, and blood concentration is measured by taking blood according to the elapsed time. also, PET-CT, bone scan, transfusion and so on will affect the outcome. Therefore, we will improve the quality of the test by providing guidelines for the GFR test for more accurate testing. Materials and Methods 5 mL of physiological saline solution and 2 mL of $^{51}Cr$-EDTA solution are used to make 5 mL of the radiopharmaceutical solution to be injected into the patient. First, the syringe weight is measured before the injection, and then the radioactive medicine is injected into the patient's vein and the syringe weight is measured after the injection. Blood sampling is performed twice in total. In adults, blood is collected 3 hours / 5 hours after injection and in children 2 hours / 5 hours after injection. The blood sample is centrifuged at 3300 rpm for 5 minutes. Standard solution is prepared by filling diluent water up to the scale indicated in the 200-mL volumetric flask, discarding $500{\mu}L$, injecting $500{\mu}L$ of GFR reagent and mixing well. $500{\mu}L$ each of the standard solution is dispensed into two test tubes, and $500{\mu}L$ of each of the plasma samples collected in time is dispensed into two test tubes and measured with a Cobra Counter. Results At present, the reference range applied in this study is $119.5{\pm}30.3ml/min/1.73m2$ for males and $125.2{\pm}28.2ml/min/1.73m^2$ for females. Conclusion The GFR test is conducted using radioactive medical products. GFR testing is performed as a scheduled test, but PET-CT, dialysis and transfusion, which may affect GFR testing, may be scheduled during GFR testing. Therefore, we could get accurate GFR test results by notifying the ward and department beforehand when booking.

• Journal of the Korean earth science society
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• v.43 no.1
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• pp.91-109
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• 2022

The ocean is a significant sink for atmospheric anthropogenic CO₂, absorbing one-third of the total CO₂ emitted by human activities. In return, oceans have experienced significant declines in seawater pH and the aragonite saturation state also called ocean acidification. This study evaluates the distribution of aragonite saturation state, an indicator to assess the potential threat from ocean acidification, by combining newly obtained data from the west coast of South Korea with previous datasets covering the Yellow Sea, East Sea, northern South China Sea, and southeast coast of South Korea. In general, offshore waters absorb atmospheric CO₂; however, most of the collected water samples show aragonite oversaturation. On the southeast coast, the aragonite saturation state was significantly affected by river discharge and associated variables, such as freshwater input with nutrients, seasonal stratification, biological carbon fixation, and bacterial remineralization. In summer, hypoxia and mixing with relatively acidic freshwater made the Jinhae and Gwangyang Bays undersaturated with respect to aragonite, possibly threatening marine organisms with CaCO₃ shells. However, widespread aragonite undersaturation was not observed on the west coast, which receives considerable river water discharge. In addition, occasional upwelling events may have worsened the ocean acidification in the southwestern part of the East Sea. These results highlight the importance of investigating site-specific ocean acidification processes in coastal waters. Along with the above-mentioned seasonal factors, the dissolution of atmospheric CO₂ and the deposition of atmospheric acidic substances will continue to reduce the aragonite saturation state in Korean waters. To protect marine ecosystems and resources, an ocean acidification monitoring program should be established for Korean waters.

• Journal of Practical Agriculture & Fisheries Research
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• v.17 no.1
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• pp.57-71
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• 2015

This study was conducted to develop the fertigation system with a peristaltic hose pump and brushless DC motor. The fertigation system was consisted of sensor, main controller, motor control unit, peristaltic pump, water supply pump, control panel, and filter. The peristaltic pump discharges liquid by squeezing the tube with rollers. Rollers attached to the external circumference of the rotor compresses the flexible tube. The fluid is contained within a flexible tube fitted inside a circular pump casing. The developed fertigation system has no mixing tank but instead injects directly a concentrated nutrient solution into a water supply pipe. The revolution speed of the peristaltic pump is controlled by PWM (Pulse width modulation) method. When the revolution speed of the peristaltic pump was 300rpm, the flow rate of the 3.2, 4.8, 6.3mm diameter tube was 202, 530, 857mL/min, respectively. As increasing revolution speed, the flow rate of the peristaltic pump linearly increased. As the inner diameter of a tube larger, a slope of graph is more steep. Flow rate of three roller was more than that of four roller. Flow rate of a norprene tube with good restoring force was more than that of a pharmed tube. As EC sensor probe was installed in direct piping in comparison with bypass piping showed good performance. After starting the system, it took 16~17 seconds to stabilize EC. The maximum value of EC was 1.44~1.7dS/m at a setting value of 1.4dS/m. The developed fertigation system showed ±0.06dS/m deviation from the setting value of EC. In field test, Cucumber plants generally showed good growth. From these findings, this fertigation system can be appropriately suitable for fertigation culture for crops.