• Korean Journal of Food Science and Technology
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• v.51 no.5
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• pp.480-485
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• 2019

The present study was conducted to compare antioxidant capacities of protein hydrolysates from four different edible insects (Protaetia brevitarsis larvae, Allomyrina dichotoma larvae, Gryllus bimaculatus imago, and Tenebrio molitor larvae) which have recently been registered as food varieties in Korea. Protein hydrolysates were prepared from each insect using enzymatic hydrolysis using alcalase, and were then separated into a fraction containing ${\leq}3kDa$. According to $RC_{50}$ values and trolox equivalent antioxidant capacity results obtained from five different antioxidant analyses, the Gryllus bimaculatus (GB) hydrolysate showed relatively high levels of antioxidant capacity and, in particular, the GB hydrolysate showed considerably strong antioxidant activities in 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and in ferric reducing antioxidant power (FRAP) assays. The GB hydrolysate also showed the strongest inhibitory effect on peroxidation of linoleic acid, and its rate of inhibition at $100{\mu}g/mL$ on day 3 of treatment was 60.26%. These results suggest that protein hydrolysates from edible insects including GB represent potential sources of natural antioxidants.

• The Journal of the Petrological Society of Korea
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• v.3 no.1
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• pp.1-19
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• 1994

We present petrography, mode and chemistry data for Fe-Ti oxide minerals from the Mesozoic granitoids in South Korea. Magnetites from the Daebo Uurassic) granites are nearly pure $Fe_3O_4$, while those from the Bulgugsa (Cretaceous) granites contain considerable amounts of Mn and Ti. This is probably related to rapid cooling of the Bulgugsa granites compared with slow cooling of Daebo granites, which is supported by geologic relations and hornblende geobarometry results of Cho and Kwon (1994) on the emplacement depth for these granites. The composition of ilmenite does not shew appreciable difference between the Daebo and Bulgugsa granites. However, $Fe_2O_3$ contents are higher for the ilmenites coexisting with magnetite than for those without magnetite. In the temperature vs. oxygen fugacity diagram, the Bulgugsa granites plot near Ni-NiO and QFM buffer curves, although only two samples show greater than the granite solidus temperature. The mode data suggest that both magnetite- and ilmenite-series exist in Daebo and Bulgusa granites from the Kyonggi massif, Ogcheon belt and Youngnam massif, while only magnetite-series exists in Bulgugsa granites from the Kyongsang basin. Many ilmenite-series granites occur in the Ogcheon belt, which might be related to assimilation of carboniferous sediments in the belt. The proportion (44 : 56) between ilmenite- and magnetite-series for the Daebo granites is significantly different from that of Ishihara et al. (1981) who showed, using magnetic susceptibility data, predominance of ilmenite-series (more than 70%) for the Daebo granites, which can be mainly attributed to preference in sampling and to wrong assignment of age for some plutons. We also found magnetite in weakly-magnetized Kanghwa granite which was formerly classified as ilmenite-series by Ishihara et al. (1981). The proportion of ilmenite-series increases in the order of hornblende biotite granite, biotite granite and two mica granite. We conclude from these observations that the ilmeniteseries granites might have originated from contamination of carboniferous crustal material and/or such source material.

• Food Science and Preservation
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• v.15 no.5
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• pp.711-718
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• 2008

Dombaeki, a traditional salted shark meat, has been widely used as a customary religious food in the Daegu-Gyeongbuk area of Korea. Two different sharks, Sphyrna zygaena (SZ) and Isurus oxyrinchus (IO) are traditionally used to prepare Dombaeki. Chemical components, lipid classes, fatty acid levels, and sterol compositions of meats prepared from the two sharks were investigated. There were no significant differences in chemical composition between the two dried shark meats. Major amino acids in shark meat were leucine, lysine, arginine, proline, isoleucine, valine, phenylalanine, glutamic acid, and asparagine, which together accounted for about 40% of total amino acids. Levels of amino acids in IO meat were higher than in SZ meat. Major fatty acids in the two shark meats were palmitic ($C_{16:0}$), stearic ($C_{18:0}$), oleic ($C_{18:1}$), arachidonic ($C_{20:4}$), and docosahexanoic (DHA, $C_{22:6}$) acids, which accounted for about 80% of total fatty acids. Notably, IO meat showed higher amounts of DHA (31.8%) and eicosapentanoic acid (EPA, 1.8%) than did SZ meat. The two shark meats showed similar dry weight levels of total lipids, with triacylglycerols, free fatty acids, sterols, and phospholipidscomprising on average 5.0, 2.0, 13.0 and 63.0% of total lipids, respectively. The dominant classes of phospholipids were mainly phosphatidylcholine (PC) and phosphatidylethanolamine (PE). PC content in the two shark meats was higher than that of PE, although the differencewas not great. The major fatty acids in phospholipids were myristic, palmitoleic, stearic, and docosanoic acids. Total volatile basic nitrogen content and the pH of SZ meat were lower than those of IO meat, whereas the Hunter's 'a' and 'b' values of SZ meat were higher than those of IO meat. These results suggest that shark meat may be useful as a functional food to prevent several degenerative diseases.

• Journal of the Korean GEO-environmental Society
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• v.20 no.5
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• pp.13-21
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• 2019

There are many cuts or natural rock slopes that remain stable for a long time in the natural environment with steep slopes ($65^{\circ}$ to $85^{\circ}$). In terms of design practice, the rock mass consisting of similar rock condition and geological structures is defined as a good continuum rock slope, and during the process of decision making angle of this rock slope, it will be important to establish the geotechnical properties estimating method of the continuum rock on the process of stability analysis in the early stages of design and construction. In this study, the stability analysis of a good continuum rock slope that can be designed as a steep slope proposed a practical method of estimating the shear strength by induced from the Hoek-Brown failure criterion, and in addition, the design applicability was evaluated through the stability analysis of steep rock slope. The existing method of estimating the shear strength was inadequate for practical use in the design, as the equivalent M-C shear strength corresponding to the H-B envelope changes sensitively, even with small variations in confining stress. To compensate for this problem, it was proposed to estimate equivalent M-C shear strength by iso-angle division method. To verify the design applicability of the iso-angle division method, the results of the safety factor and the displacement according to the change in angle of the cut slope constructed at the existing working design site were reviewed. The safety factor is FS=16~59 on the 1:0.5 slope, FS=12~52 on the 1:0.3 slope, most of which show a 10~12 percent reduction. Displacement is 0.126 to 0.975 mm on the 1:0.5 slope, 0.152 to 1.158 mm on the 1:0.3 slope, and represents an increase of 10 to 15%. This is a slightly change in normal proportion and is in good condition in terms of stability. In terms practical the working design, it was confirmed that applying the shear strength estimated by Iso-angle division method derived from the H-B failure criterion as a universal shear strength for a good continuum rock mass slope was also able to produce stable and economic results. The procedure for stability analysis using LEM (Limit Equilibrium Analysis Method) and FEM (Finite Element Analysis Method) will also be practical in the rock slope where is not distributed fault. The study was conducted by selecting the slope of study area as a good rock condition, establishing a verification for which it can be applied universal to a various rock conditions will be a research subject later on.

• Korean Journal of Heritage: History & Science
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• v.50 no.4
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• pp.122-147
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• 2017

The Jungsandong sites are distributed across quartz and mica schist formations in Precambrian, and weathering layers include large amounts of non-plastic minerals such as mica, quartz, felspar, amphibole, chlorite and so on, which form the ground of the site. Neolithic pottery from Jungsandong exhibits various brown colors, and black core is developed along the inner part for some samples, and sharp comb-pattern and hand pressure marks can be observed. Their non-plastic particles have various composition, size distribution, sorting and roundness, so they are classified into four types by their characteristic mineral compositions. I-type (feldspar pottery) is including feldspar as the pain component or mica and quartz. II-type (mica pottery) is the combination of chloritized mica, talc, tremolite and diopside. III-type (talc pottery) is with a very small amount of quartz and mica. IV-type (asbestos pottery) is containing tremolite and a very small amount of talc. The inner and outer colors of Jungsandong pottery are somewhat heterogeneous. I-type pottery group shows differences in red and yellow degree, depending on the content of feldspar, and is similar to III-type pottery. II-type is similar to IV-type, because its red degree is somewhat high. The soil of the site is higher in red and yellow degree than pottery from it. The magnetic susceptibility has very wide range of 0.088 to 7.360(${\times}10^{-3}$ SI unit), but is differentiated according to minerals, main components in each type. The ranges of bulk density and absorption ratio of pottery seem to be 1.6 to 1.7 and 13.1 to 26.0%, respectively. Each type of pottery shows distinct section difference, as porosity and absorption ratio increase in the order as follows: I-type (organic matter fixed sample) < III-type and IV-type < I-type < II-type (including IV-type of IJP-15). The reason is that differences in physical property occur according to kind and size of non-plastic particles. Although Jungsandong pottery consists of mixtures of various materials, the site pottery has a geological condition on which all mineral composition of Jungsandong pottery can be provided. There, it is thought that raw materials can be supplied from weathered zone of quartz and mica schist, around the site. However, different constituent minerals, size and rock fragments are shown, suggesting the possibility that there can be more raw material pits. Thus, it is estimated that there may be difference in clay and weathering degree.

• Korean Journal of Heritage: History & Science
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• v.39
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• pp.219-242
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• 2006

Quantitative analysis and provenance interpretation of the raw materials for the jade (amazonite) excavated from the Asan Sijeonri site were studied. Geology of the Sijeonri site composed mainly of Precambrian metasedimentary rocks and the alluvium ranges extensively. In the site, amazonite jade was excavated in the Bronze Age No. 4 circular-shaped resident site. The jade has a comma-shaped and shows light green color with so much cracks. The jade is silicate mineral of columnar habits that is shown white streak, and has fine cleavages with vitreous luster. As the analytical results, this jade was identified as a feldspar-group mineral gemologically called amazonite that is mineralogically microcline formed to intergrowth of albite and orthoclase. Internal textures of the amazonite present Na-end member of albite coexisting with K-end member of orthoclase that are replaced each other along the cleavages and twin planes with several ${\mu}m$ scales. Therefore, the amazonite is one mineral phase combined with albite and orthoclase by substitution of $Na_2O$ and $K_2O$, respectively. The Danyang are is an unique producing site of amazonite in South Korea, and Gongju Janggimyeon was known as microcline provenance to the utmost area from the Sijeonri site. In the marginal area of southern coast in Korean Peninsula, Bronze Age amazonite has been excavated in several sites, where original provenance of the raw amazonite is not identified. The Sijeonri site does not show any facilities of producing and processing traces for amazonite jade. Also, only one jade was collected in the Sijeonri site. Therefore, there is not possibility that the provenance of raw jade is the Sijeonri area. To explain original provenance of the amazonite jade, migration path, manufacturing process and archaeological interpretation are required.

• Korean Journal of Heritage: History & Science
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• v.38
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• pp.129-156
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• 2005

Increasing discovery cases of underground storage facilities made of earth, wood, or stone are being reported from the recent excavation survey of the Baekje relics. Accordingly, the purpose of this study is to examine the structure and function of the underground storage facilities of Baekje following a classification made by the type and building method as follows: plask shape, wooden box shape, and stone box shape. The plask shape storage is the most representative underground storage of Baekje that has been found in numerous relics more than 600 sets around Hangang(Han River) and Geumgang(Geum River) from the Hansung period to Sabi period in Baekje Dynasty. It is a historical artefact as a part of the unique storage culture of Baekje around Hangang and Geumgang from the 3rd to 7th Century. Considering its structure and the example of Chinese one, it might had been used for a long-term storage of grains and various other items including earth wares. The storage facility in wooden box shape and stone box shape are found mostly in the relics Of Sabi period. Thus it might had taken some functions of the storage in traditional pouch shape which had decreased after the 6th Century. In particular, the wooden box shape and stone box shape storage required enormous labor force to build owing to their structure and building method. Thus, they were considered to had been used for official purposes in province fortress and citadel artefact. The wooden box shape storage facility is classified into flat rectangular type and square type based on the structure, and into Gagu type(架構式) and Juheol type(柱穴式) based on the building method. It might had been decided according to the geography and geological feature of the place where the storage was to be built. Considering the examples of Gwanbuk-ri relics and Weolpyong-dong relics, the wooden box shape storage facility might had been used for various items depending on the needs, including foods such as fruits and essential provisions at the military base. Considering the long-term food storage, the examples in Japan, and the functional characteristics of the underground storage facility, there is a possibility that the wooden and stone box shape storage facilities had been built so as to safely store important items in case of fire. This study is only a rudimentary examination for the storage facility in Baekje. Thus further studies are to be made specifically and comprehensively on the comparison with other regions, distribution pattern, discovered relics and artefacts, and functions.

• Korean Journal of Heritage: History & Science
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• v.53 no.4
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• pp.250-273
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• 2020

The three-story stone pagodas in Hyeon-ri and Hwacheon-ri,Yeongyang Gyeongsangbuk-do are stone pagodas that exhibit the typical style of Unified Silla. The two pagodas are believed to have been built in the mid- and late 9th centuries at the latest, considering the style of the three-story roof stone on top of the double-tier base. This is also confirmed by the reliefs carved at the base and the first-story of the pagoda. The Four Heavenly Kings and the Twelve Zodiacal Animal Deities were first combined in the late 8th century in the stone pagoda at the Wonwonsa Temple Site, and the Eight Classes of Divine Beings was also the most popular carved pagoda reliefs in the 9th century. However, the two Yeongyang stone pagodas are characterized by a combination of the Four Heavenly Kings (1st story), the Eight Classes (top base), and the Twelve Zodiacal Animals (lower base), and the stone used for the pagoda consists of sedimentary rocks of the sandstone family, which comprise most of the geological strata in the Yeongyang area, rather than ordinary granite. The new combinations of the three types of guardian deities and the Eight Classes changed from seated to standing poses is interpreted as an attempt to enhance the Buddhist faith and cultural status of the Yeongyang area, along with the fact that the stone pagoda was built using local natural materials. The Eight Classes of the Yeongyang stone pagoda does not follow the two types of arrangement of the pagodas with the Eight Classes, but some of the deities have been relocated to a new location. Composed of AsuraGandharva on the east side, Naga-Mahoraga on the south, Deva-Garuda on the west, and Kimnara-Yaksa on the north, this form can be classified as a unique 'third layout of the Eight Classes' in the Yeongyang area. Such changes in the shape and posture of the reliefs reflect a new perception of the pagodas. The reason why the Gandharva and Yaksa statues were carved on the east and north sides, respectively, was because they were deemed subordinate to the Four Heavenly Kings, and the fact that the Naga and the Mahoraga were carved on the south side was presumed to have influenced the geographical location of the two pagodas on the northern side of Banbyeoncheon Stream. The Hyeon-ri and Hwacheon-ri three-story stone pagodas inherited the tradition of typical Unified Silla-period pagodas, while also bearing their own new regional characteristics.

• Journal of Applied Biological Chemistry
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• v.64 no.2
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• pp.113-119
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• 2021

Olive (Olea europaea L.) leaves, a raw material for health functional foods and cosmetics have abundant polyphenols including oleuropein (major bioactive compound) with various biological activities: antioxidant, antibacterial, antiviral, anticancer activity, and inhibit platelet activation. Oleuropein has been reported as skin protectant, antioxidant, anti-ageing, anti-cancer, anti-inflammation, anti-atherogenic, anti-viral, and anti-microbial activity. Despite oleuropein is the important compound in olive leaves, there is still no quantitative approach to reveal oleuropein content in commercial products. Therefore, a validated method of analysis has to develop for oleuropein. In this study, the components and oleuropein content in 10 types of products were analyzed using a developed method with ultra-performance liquid chromatography to quadrupole time-of-flight mass spectrometry, charge of aerosol detector, and photodiode array. The total of 18 compounds including iridoids (1, 3, 4, 14, and 16-18), coumarin (2), phenylethanoids (5, 9, and 11), flavonoids (6-8, 10, 12, and 13), lignan (15), were tentatively identified in the leaves extract based high resolution mass spectrometry data, and the content of oleuropein in each product was almost identical between two detection methods. The oleuropein in three commercial product (A, G, H) was contained more over the suggested content, and it of five products (B, E, H, I, J) were analyzed within 5-10% error range. However, the two products (C, D) were found far lower than suggested contents. This study provides that analytical results of oleuropein could be a potential information for the quality control of leaf extract for a manufactured functional food.

• Korean Journal of Remote Sensing
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• v.38 no.2
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• pp.139-151
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• 2022

SAGD (Steam-Assisted Gravity Drainage) method is widely used for oil recovery in oil sands regions. The SAGD operation causes surface displacement, which can affect the stability of oil recovery plants and trigger various geological disasters. Therefore, it isimportant to monitor the surface displacement due to SAGD in the oil sands region. In this study, the surface displacement due to SAGD operations of the Athabasca oil sands region in Alberta, Canada, was observed by applying Permanent Scatterer Interferometric Synthetic Aperture Radar (PSInSAR) technique to the Sentinel-1 time series SAR data acquired from 2016 to 2021. We also investigated the construction and expansion of SAGD facilitiesfrom Landsat-7/8 time seriesimages, from which the characteristics of the surface displacement according to the oil production activity of SAGD were analyzed. Uplift rates of 0.3-2.5 cm/yr in the direction of line of sight were observed over the SAGDs and their vicinity, whereas subsidence rates of -0.3--0.6 cm/yr were observed in areas more than several kilometers away from the SAGDs and not affected by oil recovery activities. Through the analysis of Landsat-7/8 images, we could confirm that the SAGDs operating after 2012 and showing high oil production activity caused uplift rates greater than 1.6 cm/yr due to the subsurface steam injection. Meanwhile, very small uplift rates of several mm per year occurred over SAGDs which have been operated for a longer period of time and show relatively low oil production activity. This was probably due to the compression of reservoir sandstone due to continuous oil recovery. The subsidence observed in areas except for the SAGDs and their vicinity estimated to be a gradual land subsidence caused by melting of the permafrost. Considering the subsidence, it was expected that the uplift due to SAGD operation would be greater than that observed by the PSInSAR. The results of this study confirm that the PSInSAR can be used as an effective means for evaluating productivity and stability of SAGD in the extreme cold regions.