• Korean Journal of Food Science and Technology
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• v.26 no.5
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• pp.500-506
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• 1994

For comparison of beef quality, four kinds of beef (Korean native cattle beef, dairy cattle beef, imported beef, cross-bred beef) were investigated through tenderness, juiciness and flavor related components measurement and organoleptic tests. Flavor related chemical components such as NPN, IMP, free fatty acid and free amino acids were analyzed, water holding capacity, contents of hydroxyproline and intramuscular fat were measured for evaluation of beef tenderness. Instron was also used for measuring beef tenderness as an objective method. Triangle test and descriptive analysis test were conducted for comparison and evaluation of preference of various beef samples. In hardness analysis using Instron, imported and cross-bred beefs had higher value than that of Korean native cattle or dairy cattle beef. Water holding capacity and pH of Korean cattle beef was higher than that of others. The intramuscular fat content of Korean cattle beef was highest, so it was expected juicier than other beef. In flavor related compound analysis, NPN content of Korean native cattle beef was the lowest, which shows it spent the least time among sample meats after slaughter. IMP, hypoxantine and inosine were most abundant in Korean native cattle beef. In free amino acids analysis showed that the proportion of basic acid and aromatic acid content of Korean native cattle beef was highest, whereas that of sulfur containing amino acid of imported beef was highest. TBA value of Korean native cattle beef was the lowest, and analysis of fatty acid composition revealed that the proportion of unsaturated fatty acid of Korean native cattle beef was higher than imported and dairy cattle beef, but similar to cross-bred beef. Organoleptic test was performed by triangle test and descriptive analysis. In triangle test, most panelist could distinguish Korea native cattle beef from imported beef and cross-bred beef, imported beef from cross-bred beef. In descriptive analysis which relys on subjective standards of panelists, there was no difference among beef in aroma, flavor and tenderness except juiciness. Even though contents of non volatile flavor compounds in Korean native cattle beef were higher than those of other beef samples, there were no significant differences in subjective panel test. The results showed that Korean consumers do not have common standards for beef quality evaluation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.6
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• pp.611-616
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• 2001

The bacteriological and physiochemical analysis of seawater in Tongyeong harbor was conducted to evaluate sanitary conditions, The samples were collected at 6 stations established once a month from January to December, 2000. During the study period, the ranges of temperature, transparency, chemical oxygen demand, dissolved oxygen, dissolved nitrogen, phosphate and chlorophyll-a were $6.8\sim25.2^{\circ}C,\;1.0\sim2.5\;m,\;1.79\sim2.41\;mg/L,\;5.7\sim10.1\;mg/L,\;6.59\sim10.53{\mu}g-at/L,\;0.56\sim1.01{\mu}g-at/L\;and\;1.21\sim9.54\;mg/m^3$, respectively, The viable cell counts of seawater in Tongyeong harbor ranged from $3.0\times10^4CFU/mL\;to\;6.9\times10^6CFU/mL$. The coliform group and fecal coliform MPN's of the samples were ranged $23\~4,600\;MPN/100\;mL$ (means 540 MPN/100 mL) and $11\~1,600\;MPN/100\;mL$ (means 210 MPN/100 mL), respectively, The coliform group was classified with IMViC reactions and pathogenic vibrios were analyzed. Two hundred eighteen strains that were obtained from seawater samples in Tongyeong harbor represented Escherichia coli group, $66.1\%$; Citrobacter freundii group, $11.0\%$; Enterobacter aerogenes, $9.6\%$; and unknown, $13.3\%$, respectively. During the study period, infectious bacteria such as Vibrio cholerae O1, Salmonella sp. and Shigella sp. were not detected from the samples, but detection ratios of V. parahaemolyticus, V cholerae non-O1 and V. vulnificus were $10.0\sim30.1\%$.

• Journal of Wetlands Research
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• v.25 no.2
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• pp.145-158
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• 2023

Constructed wetlands (CWs) are effective technologies for urban wastewater management, utilizing natural physico-chemical and biological processes to remove pollutants. This study employed a bibliometric analysis approach to investigate the progress and future research trends in the field of CWs. A comprehensive review of 100 most-recently published and open-access articles was performed to analyze the performance of CWs in treating wastewater. Spain, China, Italy, and the United States were among the most productive countries in terms of the number of published papers. The most frequently used keywords in publications include water quality (n=19), phytoremediation (n=13), stormwater (n=11), and phosphorus (n=11), suggesting that the efficiency of CWs in improving water quality and removal of nutrients were widely investigated. Among the different types of CWs reviewed, hybrid CWs exhibited the highest removal efficiencies for BOD (88.67%) and TSS (95.67%), whereas VSSF, and HSSF systems also showed high TSS removal efficiencies (83.25%, and 78.83% respectively). VSSF wetland displayed the highest COD removal efficiency (71.82%). Generally, physical processes (e.g., sedimentation, filtration, adsorption) and biological mechanisms (i.e., biodegradation) contributed to the high removal efficiency of TSS, BOD, and COD in CW systems. The hybrid CW system demonstrated highest TN removal efficiency (60.78%) by integrating multiple treatment processes, including aerobic and anaerobic conditions, various vegetation types, and different media configurations, which enhanced microbial activity and allowed for comprehensive nitrogen compound removal. The FWS system showed the highest TP removal efficiency (54.50%) due to combined process of settling sediment-bound phosphorus and plant uptake. Phragmites, Cyperus, Iris, and Typha were commonly used in CWs due to their superior phytoremediation capabilities. The study emphasized the potential of CWs as sustainable alternatives for wastewater management, particularly in urban areas.

• Economic and Environmental Geology
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• v.56 no.2
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• pp.139-153
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• 2023

This study aimed to understand the spatiotemporal variations in nitrogen content in the Gyeongan stream along the main stream and at the discharge points of the sub-basins, and to identify the origin of the nitrogen. Field surveys and laboratory analyses, including chemical compositions and isotope ratios of nitrate and boron, were performed from November 2021 to November 2022. Based on the flow duration curve (FDC) derived for the Gyeongan stream, the dry season (mid-December 2021 to mid-June 2022) and wet season (mid-June to early November 2022) were established. In the dry season, most samples had the highest total nitrogen(T-N) concentrations, specifically in January and February, and the concentrations continued to decrease until May and June. However, after the flood season from July to September, the uppermost subbasin points (Group 1: MS-0, OS-0, GS-0) where T-N concentrations continually decreased were separated from the main stream and lower sub-basin points (Group 2: MS-1~8, OS-1, GS-1) where concentrations increased. Along the main stream, the T-N concentration showed an increasing trend from the upper to the lower reaches. However, it was affected by those of the Osan-cheon and Gonjiamcheon, the tributaries that flow into the main stream, resulting in respective increases or decreases in T-N concentration in the main stream. The nitrate and boron isotope ratios indicated that the nitrogen in all samples originated from manure. Mechanisms for nitrogen inflow from manure-related sources to the stream were suggested, including (1) manure from livestock wastes and rainfall runoff, (2) inflow through the discharge of wastewater treatment plants, and (3) inflow through the groundwater discharge (baseflow) of accumulated nitrogen during agricultural activities. Ultimately, water quality management of the Gyeongan stream basin requires pollution source management at the sub-basin level, including its tributaries, from a regional context. To manage the pollution load effectively, it is necessary to separate the hydrological components of the stream discharge and establish a monitoring system to track the flow and water quality of each component.

• Journal of Animal Science and Technology
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• v.47 no.6
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• pp.1059-1066
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• 2005

The objective of this study was to investigate the physico-chemical characteristics of chicken breast surimi processed by four times washing (C) and adjustment to pH 3.0 (T1) and pH 11.0 (T2). Water, crude protein, myofibrillar protein and yield of the treatment C were lower compared to other two treatments. Crude fat of T2 was higher than other two treatments. pH, WHC, breaking force and deformation were not different among the treatments. Shear force of T2 was the highest, followed by T1 and C. L* of T2 and a* of T1 were lower than other two treatments. b* of C was the highest, while T2 was the lowest. Brittleness and hardness in textural properties were not different among the treatments. Cohesiveness of T1 was the lowest among three treatments. Springiness and chewiness of T1 and T2 were higher than those of treatment C, respectively. Gumminess of T2 were higher compared to C and T1. Appearance and flavor in sensory evaluation were the highest in T1 and the lowest in C among three treatments. Color, aroma, juiciness, tenderness and overall acceptability were not different among the treatments. In conclusion, physico-chemical quality of chicken breast surimi was the highest in T2 among three treatments.

• Journal of the Mineralogical Society of Korea
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• v.15 no.4
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• pp.329-344
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• 2002

Mineralogical and chemical characterization of some domestic bentonites, such as quantitative XRD analysis, chemical leaching experiments, pH and CEC determinations, were done without any separation procedures to understand their relationships among mineral composition, characteristics, and cation exchange properties. XRD quantification results based on Rietveld method reveal that the bentonites contain totally more than 25 wt% of impurities, such as zeolites, opal-CT, and feldspars, in addition to montmorillonite ranging 30～75 wt%. Cation exchange properties of the zeolitic bentonites are deeply affected by the content of zeolites identified as clinoptilolite-heulandite series. Clinoptilolite is common in the silicic bentonites with lighter color. and occurs closely in association with opal-CT. Ca is mostly the dominant exchangeable cation, but some zeolitic bentonites have K as a major exchangeable cation, The values of cation exchange capacity (CEC) determined by Methylene Blue method are comparatively low and have roughly a linear relationship with the montmorillonite content of the bentonite, though the correlated data tend to be rather dispersed. Compared to this, the CEC determined by Ammonium Acetate method, i.e.‘Total CEC’, has much higher values (50～115 meq/100 g). The differences between those CEC values are much greater in zeolitic bentonites, which obviously indicates the CEC increase affected by zeolite. Other impurities such as opal-CT and feldspars seem to affect insignificantly on the CEC of bentonites. When dispersed in distilled water, the pH of bentonites roughly tends to increase up to 9.3 with increasing the alkali abundance, especially Na, in exchangeable cation composition. However, some bentonites exhibit lower pH (5～6) so as to regard as ‘acid clay’. This may be due to the presence of $H^{＋}$ in part as an exchangeable cation in the layer site of montmorillonite. All the works of this study ultimately suggest that an assesment of domestic bentonites in grade and quality should be accomplished through the quantitative XRD analysis and the ‘Total CEC’measurement.

• Korean Journal of Soil Science and Fertilizer
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• v.26 no.3
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• pp.172-180
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• 1993

Chemical properties of the soils were surveyed in the field of vinyl houses concentrated in the area of Bunpyong-dong and Shinchon-dong of Cheongju, Chilgeum-dong of Chungju and Gageum-myeon of Jungweon-gun. Chungcheongbuk-do province. 1. Content of chemical component of the soil in the vinyl house was higher than in open field. In more than half of the vinyl house soils surveyed, electric conductivity was more than 4.0 mmhos/cm and available phosphate was more than 1,000ppm. 2. Contents of availble phosphate and exchangeable potassium were increased with years of cultivation and their content of accumulation in soil were in the order of Bunpyong-dong>Shinchon-dong>Gageum-myeon>Chilgeum-dong. While their mobility was comparatively low. 3. $NO_3$-N content was remarkably higher in vinyl house soil and the older in cultivation made $NO_3$-N content higher same as the case of available phosphate content. However easy leaching of $NO_3$-N through soil profile is expected due to the fact that $NO_3$-N content was rapidly decreased by removal of polyethylene film cover from the frame of house after harvest of crops. 4. It is a tendency that various chemical contents of vinyl house soils wer higher in 1992 than in 1988~1990, especially much higher from the area of Bunpyong-dong and Shinchon-dong of Cheongju. 5. Salt accumulation in vinyl house soil has been increased with continuing cultivation. Therefore amount of fertilizer application should be controlled in order to avoid salt toxicity, quality deterioration for crop and salt contamination of ground water.

• Journal of Korean Society of Forest Science
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• v.88 no.2
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• pp.149-156
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• 1999

This research was carried out to investigate the effects of the different tree species(Q. spp., L. leptolepis and P. koraiensis) about the chemical properties of throughfall and stemflow, to purify the acid rain at Kyung Hee Univ. experimental forest, Gwangju-gun, Kyunggi-do. The water quality of the precipitation, throughfall and stemflow in each forest stands were analyzed chemically. The throughfall pH ranges were Q. spp.(pH 4.96-6.34), L. leptolepis(pH 3.96-6.41) and P. koraiensis(pH 4.11-6.36), and the stemflow pH ranged Q. spp.(pH 4.33-6.05), L. leptolepis(pH 3.59-6.09) and P. koraiensis(pH 3.60-6.13). pH values of throughfall and stemflow to the precipitation were Q. spp. higer than L. leptolepis and P. koraiensis, while distribution range was small. Therefore, buffering capacity about the precipitation in the tree species trended Q. spp. bigger than L. leptolepis and P. koraiensis. Nearly all concentration of dissolved elements were precipitation${\leq}$throughfall${\leq}$stemflow. The cation ($Ca^{2+}$, $Mg^{2+}$, $K^+$ and $NH_4{^+}$), and anion($Cl^-$ and $NO_3{^-}$) were increased. Especially the concentration of $Mg^{2+}$, $K^+$, $NH_4{^+}$ and $Cl^-$ were noticeable. In comparing concentration of dissolved elements of throughfall with each tree species, $Ca^{2+}$ concentration was Q. spp.$NH_4{^+}$ was Q. spp.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.3
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• pp.426-434
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• 2011

In order to increase the use of rice, ginseng Garaedduks and Topokki were made and the physicochemical and sensory properties were investigated. Topokki and Garaedduks were added with 0, 1, 3 and 5% ginseng powder and stored at $20^{\circ}C$ for 48 hours. The moisture contents were not different to the increasing amount of ginseng powder and increasing storage time for 48 hours. The moisture content of Garaedduks for control and 5% added ginseng powder were 48.08% and 49.62%, respectively. The L value in color of uncooked ginseng Garaedduk decreased according to the added amount of ginseng powder, and the b value in color increased significantly according to the added amount of ginseng powder and during 48 hours storage at $20^{\circ}C$. Textural analysis, measured using a texture analyzer, of Garaedduk revealed that hardness, cohesiveness, chewiness decreased significantly and adhesiveness increased according to the added amount of ginseng powder. In sensory evaluation, 5% ginseng Garaedduk (uncooked, cooked) scored higher in overall acceptability than those of the other samples. In cooking properties, water absorption and solid contents increased according to the added amount of ginseng powder. Therefore, Garaedduk containing 5% ginseng powder was the most preferable. These results implied that the degree of retrogradation of ginseng Garaedduk might be low due to its high dietary fiber content.

• Applied Biological Chemistry
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• v.22 no.3
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• pp.160-165
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• 1979

This study was carried out to investigate effects of iron content on the quality of soy sauce, bean paste and red pepper paste, and to elucidate the origin of iron and change of the contents during production processes. For the first step, the iron contents in commercial soy sauce and changes of the contents during brewing process were determined. The results obtained were as follows. 1, Iron contents of raw materials were 108 ppm in soy bean, 133ppm in defatted soy bean, 79 ppm in wheat, 5 ppm in sodium chloride, 58 ppm in seed koji, 300-2000 ppm in spore of Aspergillus oryzae, 240 ppm in wheat gluten, 20 ppm in sodium carbonate (above figures were of dry weight basis), 6 ppm in hydrochloric acid, 18 ppm in caramel and 0.3ppm in brewing water respectively. 2, Iron contents in koji were 200-240 ppm (as dry weight basis) and increased, more or less, in progress of koji-making period. 3. Iron contents in the mashes during fermentation were 40 rpm after 1 month, 43-47 ppm after 3 months and 49-62ppm after 6 months. 4. In chemical soy sauce, the iron content was 159 ppm after hydrolysis of wheat gluten with hydrochloric acid, and 184 ppm after neutralization. 5. Higher iron contents were detected both in fermented and chemical soy sauce when the concentration of total nitrogen increased, but the levels were higher in chemical soy sauce than in fermented one at the same concentration of total nitrogen. 6. In the case of fermented soy sauce, the iron content in the filtrate was decreased by press-filtration, but no significant change was found between before and after heat-sterilization. 7. Iron contents in commercial soy sauce were varied with the producers, however, the average value was 62.7 ppm as calculated as 1.0 percent of total nitrogen. And the average level of iron in home-made soy sauce produced by conventional method was 37.68 ppm.