• Current Research on Agriculture and Life Sciences
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• v.5
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• pp.81-88
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• 1987

This study was conducted to determine the contents of heavy metals in Jeotkals (salted-fermented fish and shellfishes) and to investigate the major factor of their contamination. The results were as follows : Average contents of heavy metals in Jeotkals were Hg 0.076 ppm, Pb 0.677 ppm, Cd 0.112ppm, As 1.025ppm, Cu 3.540ppm, Zn 11.230ppm and Mn 2.041ppm, those in fish and shellfishes were Hg 0.051ppm, Pb 0.425ppm, Cd 0.071ppm, As 0.632ppm, Cu 2.ppm, Zn 8.052ppm, Mn 1.178ppm and Hg ND, Pb 0.05ppm, Cd 0.01ppm, As 0.02ppm, Cu 0.087ppm, Zn 0.068ppm and Mn 0.044ppm in salts. During the fermentation of the salted anchovy (Engraulis Japonicus) in each containers, the contents of Hg and Cd had little difference with control, but Pb was high in pottery and iron container and As was in iron and regenerated plastic container. During the fermentation of the salted anchovy in iron container, the contents of heavy metals increased and was to determined more at the later stage of fermentation than at the early stage. Most contents of heavy metals increased in elution experiment of containers, but Hg and Cd did not detected. The concentration of salt did not affect to the elution of heavy metals.

• Journal of agriculture & life science
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• v.45 no.5
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• pp.81-89
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• 2011

This study was carried out to investigate changes in physicochemical and sensory properties of cooked sausages replaced sodium chloride (NaCl) to potassium chloride (KCl) or magnesium chloride ($MgCl_2$) during storage for 30 days under $4^{\circ}C$. All sausages were prepared with different combination of salts as follow; CTL (1.5% NaCl), KCL (0.9% NaCl+0.6% KCl), MCL (0.9% NaCl+0.6% $MgCl_2$), KML (0.9% NaCl+0.3% KCl+0.3% $MgCl_2$) and PST (1.5% PanSalt). Among sausages moisture content in KML was the highest (p<0.05). Lightness and redness in CTL were lower than those of other treatments, but MCL and KML containing $MgCl_2$ showed higher CIE $L^*$ and $a^*$ values than CTL. The pH in CTL was the highest during storage, however, no significant difference was determined between two treatments, MCL and KML (p>0.05). Crude fat content and water holding capacity (WHC), hardness and cohesiveness of MCL sausages were higher than those of CTL. In sensory characteristics of cooked sausages, saltness in MCL was the lowest during 10 and 20 days of storage (p<0.05). Yellowness in PST was lower than other treatmeants. Gumminess and chewiness of texture property of sausages from MCL and KML were higher than CTL. The results indicate that the replacement of NaCl by KCl improved texture, but meat color was not improved as expected. In contrast, the replacement of NaCl by $MgCl_2$ enhanced color, texture and WHC, whereas partial replacement of NaCl by $MgCl_2$ must reduce bitter taste as compared to sausages manufactured with a NaCl only. Therefore, $MgCl_2$ may be a salt replacing NaCl in cooked pork sausages.

• Food Science and Preservation
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• v.19 no.6
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• pp.951-956
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• 2012

In this study, the effects of the use of a starter on radish soaked at $4^{\circ}C$ for 28 days using two kinds of domestic sun-dried salt (white and gray salt) were determined. As a result, the moisture contents of the radish soaked with white and gray salt were 7.93 and 4.50%, respectively. The salinity levels were found to be equal (90%). No significant difference was found between the two groups in terms of the mineral contents of the salts therein ($37812.41{\pm}1922.95$ and $39755.13{\pm}1205.70$ mg/100 g, respectively). However, iron and zinc contents of gray salt were higher than those of white salt while the calcium, potassium, and magnesium contents were lower than those of white salt. After the addition of the starter, the sugar content increased, the pH decreased, and the total acidity rapidly decreased compared with the non-starter group during fermentation. The total microorganism count of the two groups increased during the fermentation period of 28 days. From the initial fermentation for 7 days, the lactic acid bacteria in the non-starter group increased while those in the leuconostoc starter group steadily increased within the whole fermentation period. The Leuconostoc spp. in non-starter group increased, but that in the starter group decreased to pH 4.0 on day 14.

• Korean Journal of Heritage: History & Science
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• v.50 no.2
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• pp.116-139
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• 2017

Naksansa Temple was famous for a miracle temple where Lee Haeng-ri(李行里), King Ikjo(翼祖), had prayed for offspring and soon begat King Dojo(度祖). According to the First King's Annals("太祖實錄"), King Dojo was the person who directly received prophecy of founding a Joseon. For these reasons, Naksansa Temple received attention concerning the foundation of Joseon. The birth story of King Dojo and his father's prayer at the Avalokitesvara Bodhisattva cave(觀音窟), Naksansa Temple, was well known among the noblemen and royal families until the Late Joseon period. Lee Seoung gye(李成桂) paid particular attention to the Naksansa Temple, and King Sejo(世祖) also made people rebuild the temple when he went for a royal tour in Gangwon-do. Naksansa Temple was built during the time when King Sejo made many temples in order to strengthen the royal authority. King Sejo made people extensively rebuild the temple, praying for health and longevity of King Yejong(his son). King Sejo's will of rebuilding the Naksansa Temple was very strong. The residents of the area had to pay a huge cost because the rebuilding of the Naksansa Temple was a big construction. Hak-yeol(學悅), who had a responsibility of rebuilding the Naksansa Temple, forcedly obtained supplies as he received protection from the royal family. Naksansa Temple thrived with the protection of the royal family after rebuilding. King Yejong and Seongjong gave Naksansa Temple slaves and fields(田地). He also bestowed upon the temple the salts which was the tribute paid by Gangwon-do. In order to protect the precincts of the Naksansa Temple, the government closed the Yang Yang Main Street near Naksansa Temple and built a new road. And the signs of preventing fishing(捕漁) was built along the coast of Naksan in four kilometers in order to keep people out. Although the Naksansa Temple declined in the late Joseon period, it still received support under the protection policy and maintained its reputation as an original Buddhist shrine.

• Journal of Dairy Science and Biotechnology
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• v.37 no.2
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• pp.115-128
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• 2019

Lactic acid bacteria obtained from traditional Kimchi were selected on the basis of their caseinolytic activity and lactose usability and examined for availability as a starter in probiotic activity. Thirty-two strains were selected as lactic acid producing bacteria in BCP agar, and two strains (KC23 and KF26) with more than 90% resistance for both acid and bile salts were selected. The two strains were identified as L. plantarum (KC23) and L. paracasei (KF26) by API 50 CHL system and 16S rRNA sequence analysis. L. plantarum (KC23) was finally selected based on its biochemical characteristics for lactose and raffinose usability. Free tyrosine content increased rapidly in 10% skimmed milk medium, from $24.1{\mu}g/mL$ after 8 h to $43.9{\mu}g/mL$ after 16 h. Additionally, the caseinolytic clear zone of 12 mm of L. plantarum (KC23) was greater than the 9 mm zone of commercial L. acidophilus CSLA. The bacterium exhibited mesophilic growth and yielded $8.9{\times}10^8CFU/mL$ when incubated at $37^{\circ}C$ for 12 h at pH 4.25. Moreover, L. plantarum KC23 exhibited antibacterial activity as it formed a clear zone of 8-13 mm for the 5 pathogens. Adherent activity was 2.23 fold higher than that of LGG. The acidity of 10% skimmed milk fermented for 12 h was 0.74%.

• Journal of the Korean Electrochemical Society
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• v.22 no.3
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• pp.128-137
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• 2019

A lithium is the lightest metal on the earth. It has some attractive characteristics as a negative electrode material such as a low reduction potential (-3.04 V vs. SHE) and a high theoretical capacity ($3,860mAh\;g^{-1}$). Therefore, it has been studied as a next generation anode material for high energy lithium batteries. The thin lithium electrode is required to maximize the efficiency and energy density of the battery, but the physical roll-press method has a limitation in manufacturing thin lithium. In this study, thin lithium electrode was fabricated by electrodeposition under various conditions such as compositions of electrolytes and the current density. Deposited lithium showed strong relationship between process condition and its characteristics. The concentration of electrolyte affects to the shape of deposited lithium particle. As the concentration increases, the shape of particle changes from a sharp edged long one to a rounded lump. The former shape is favorable for suppressing dendrite formation and the elec-trode shows good stripping efficiency of 92.68% (3M LiFSI in DME, $0.4mA\;cm^{-2}$). The shape of deposited particle also affected by the applied current density. When the amount of current applied gets larger the shape changes to the sharp edged long one like the case of the low concentration electrolyte. The combination of salts and solvents, 1.5M LiFSI + 1.5M LiTFSI in DME : DOL [1 : 1 vol%] (Du-Co), was applied to the electrolyte for the lithium deposition. The lithium electrode obtained from this electrolyte composition shows the best stripping efficiency (97.26%) and the stable reversibility. This is presumed to be due to the stability of the surface film induced by the Li-F component and the DOL effect of providing film flexibility.

• Clean Technology
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• v.28 no.4
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• pp.269-277
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• 2022

With the recent development of the biological enzymatic reaction industry, lactic acid (LA) can be mass-produced from biomass sources. In particular, a catalytic process that converts LA into acrylic acid (AA) is receiving much attention because AA is used widely in the petrochemical industry as a monomer for superabsorbent polymers (SAP) and as an adhesive for displays. In the LA conversion process, NaY zeolites have been previously shown to be a high-activity catalyst, which improves AA selectivity and long-term stability. However, NaY zeolites suffer from fast deactivation due to severe coking. Therefore, the aim of this study is to modify the acid-base properties of the NaY zeolite to address this shortcoming. First, base promoters, Ca ions, were introduced to the NaY zeolites to tune their acidity and basicity via ion exchange (IE) and incipient wetness impregnation (IWI). The IWI method showed superior catalyst selectivity and stability compared to the IE method, maintaining a high AA yield of approximately 40% during the 16 h reaction. Based on the NH₃- and CO₂-TPD results, the calcium salts that impregnated into the NaY zeolites were proposed to exit as an oxide form mainly at the exterior surface of NaY and act as additional base sites to promote the dehydration of LA to AA. The NaY zeolites were further treated with KOH before calcium impregnation to reduce the total acidity and improve the dispersion of calcium through the mesopores formed by KOH-induced desilication. However, this KOH treatment did not lead to enhanced AA selectivity. Finally, calcium loading was increased from 1wt% to 5wt% to maximize the amount of base sites. The increased basicity improved the AA selectivity substantially to 65% at 100% conversion while maintaining high activity during a 24 h reaction. Our results suggest that controlling the basicity of the catalyst is key to obtaining high AA selectivity and high catalyst stability.

• Korean Journal of Plant Resources
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• v.35 no.4
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• pp.435-444
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• 2022

Hibiscus hamabo Sieb. et Zucc. (yellow hibiscus) is a deciduous semi-shrub plant and mainly growing in Jeju Island. This is known the unique wild hibiscus genus and classified as an 2nd grade of endangered plant for Korean Red List. In previous studies, properties of germination, ecological, genetical and salt resistance have been reported. In this study, we investigated mass-proliferated adventitious root using bioreactor, antioxidant and whitening effects to conduct functional ingredients. Yellow hibiscus were collected from Gujwa, Jeju by prior permission and they were introduced by explant type and various medium composition after surface sterilization. As a result, seed response rates were evaluated at range of 51.17~51.83%, in terms of comprehensive efficiency of shoot and root formation. In the case of adventitious root propagation condition was confirmed in half strength Murashige and Skoog medium salts, 30 mg/L sucrose, and 2 mg/L indole-3-butyric acid for 8 weeks in 5,000 mL bioreactor. We also compared between relationship with biomass and secondary metabolites accumulation by total phenolics content, the flavonoid content, DPPH free radical scavenging activity and melanin content. The results indicated that adventitious root mass proliferation, antioxidant and whitening effect could develop value of the high-quality cosmeceutical ingredient and further metabolite studies.

• Economic and Environmental Geology
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• v.56 no.1
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• pp.103-114
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• 2023

The Christian Museum of Gongju Jeil Church was first built in 1931 and was largely damaged during the Korean War, but the walls and chimneys have been preserved. This building has a high architectural values in that the chapel was reconstructed in 1956, and maintains its original form through repair of damaged parts rather than new construction. The stained glass windows were as installed in 1979 and has a great significance in the Dalle de Verre method using lump glass. However, some of the stained glass damaged partially, such as various cracks and splits, and vertical and horizontal cracks in the joint fillers of supporting the colored glass. As the structural materials of the stained glass window, an iron frame and cement mortar filled with it were used, and corrosion of iron, cracking of mortar and granular decomposition appear partially due to weathering. In the joint fillers, the content of Ca and S is very high, indicating that gypsum were used as admixtures, and the gypsums grow in a rhombohedral and forms a bundle, which is investigated to have undergone recrystallization. As a result of modeling the ultrasonic velocity at the joint fillers, the left and right windows at the entrance show relatively weak in the range of 800 to 1,600m/s, and the lower right corner of the altar window and the upper left corner of the center window were also 1,000 to 1,800m/s, showing relatively low physical properties. And gypsums produced during the neutralization of lime mortar were detected in the joint fillers and contaminants on the surface. Such salts may cause damage to the joint material due to freezing and thawing, so appropriate preventive conservation is required. Also, since various damage types are complexly appearing in stained glass window and joint filler, customized conservation treatment should be reviewed through clinical tests.

• Korean Journal of Soil Science and Fertilizer
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• v.2 no.1
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• pp.15-26
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• 1969

The study on physico-chemical characteristics of the acid sulfate soil present in Kimhae plain was carried out with 28 surface and subsoils from lower and higher produtive area and two representative profile samples from the areas reclaimed a few decades ago and around 10 years ago respectively. 1. There are no differences in soil texture between lower and higher productive soils being mostly silty clay loam and silty clay. 2. Very significant differences in pH, degree of base saturation and extractable aluminium content are observed; lower pH, lower degree of base saturation and higher aluminium in the lower productive soils and subsoils. The pH and degree of base saturation of these soils are extremely low whereas aluminium content is very high compared to ordinary paddy soil. 3. Cation exchange capacity of these soils are slightly higher than ordinary paddy soils. In higher productive soils, exchangeable calcium and magnesium are of same order, whereas in lower productive soils magnesium content is appreciably higher than calcium. 4. Though the soil is derived from marine and estuarine sediment, the soluble salt content is not high. There are only few lower productive surface soils and subsoils having Ec values of the saturation extracts higher than 4 mmhos but lower than 9 mmhos/cm. 5. Organic matter content of these soils is a bit higher compared to ordinary paddy soils, but, nitrogen content is comparatively low. C/N ratio of these soils is around 12. 6. Sulfur content is considerably higher but oxidizable sulfur is found to be very low. Total sulfur is generally high in subsoils and lower productive soils. 7. Active iron and available silica are slightly higher than ordinary paddy soils but easily reducible manganese is very low. Almost no differences are also observed between lower and higher productive soils. 8. Available phosphorus content is extremely low in particular, regardless of higher or lower productive soils. 9. The two representative profiles from the area of earlier reclamation and recent one show that samples from earlier reclaimed area contain less amount of free acids, sulfur compounds, toxic aluminium and soluble salts etc. than the other. This indicate greater leaching and possible addition of lime for a longer period of time. 10. From the results obtained, it can be concluded the higher productivity of group I soils is due to the greater leaching and neutralisation of acidity by liming materials, It can also be concluded that the productivity of both types can be increased by addition of liming materials and improvement of drainage facilities.