• Korean Journal of Food Science and Technology
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• v.53 no.3
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• pp.278-289
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• 2021

The rapid aging of society has led to a surge in cognitive dysfunction in the elderly. As there is limited evidence for the development of dementia in medicine, a shift in focus on prevention strategies using bioactive compounds in food is required. This systematic review evaluated the effects of various bioactive compounds on age-associated cognitive decline. The literature was searched for terms related to bioactive compounds in cognitive decline and article selection was limited to clinical randomized controlled trials for a single bioactive compound. We identified 21 studies that evaluated the strength of the evidence. ω-3 fatty acids and vitamin B presented a strong evidence level, whereas vitamin D and E, anserine/carnosine, and chromium were defined as having moderate levels of evidence. ω-3 fatty acids relieved cognitive decline and reduced amyloid β-related protein accumulation. Vitamin B decreased homocysteine levels, which is accompanied by alleviation of cognitive function. In conclusion, ω-3 and vitamin B have the potential to improve age-associated cognitive decline.

• Applied Chemistry for Engineering
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• v.33 no.2
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• pp.173-178
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• 2022

A lateral flow immunoassay (LFIA) method using carbon nanodot@silica as a signaling material was developed for analyzing the concentration of retinol-binding protein 4 (RBP4), one of the lung cancer biomarkers. Instead of antibodies mainly used as bioreceptors in nitrocellulose membranes in LFIA for protein detection, aptamers that are more economical, easy to store for a long time, and have strong affinities toward specific target proteins were used. A 5' terminal of biotin-modified aptamer specific to RBP4 was first reacted with neutravidin followed by spraying the mixture on the membrane in order to immobilize the aptamer in a porous membrane by the strong binding affinity between biotin and neutravidin. Carbon nanodot@silica nanoparticles with blue fluorescent signal covalently conjugated to the RBP4 antibody, and RBP4 were injected in a lateral flow manner on to the surface bound aptamer to form a sandwich complex. Surfactant concentrations, ionic strength, and additional blocking reagents were added to the running buffer solution to optimize the fluorescent signal off from the sandwich complex which was correlated to the concentration of RBP4. A 10 mM Tris (pH 7.4) running buffer containing 150 mM NaCl and 0.05% Tween-20 with 0.6 M ethanolamine as a blocking agent showed the optimum assay condition for carbon nanodot@silica-based LFIA. The results indicate that an aptamer, more economical and easier to store for a long time can be used as an alternative immobilizing probe for antibody in a LFIA device which can be used as a point-of-care diagnosis kit for lung cancer diseases.

• Journal of Christian Education in Korea
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• v.70
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• pp.37-74
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• 2022

COVID-19, which occurred in Wuhan, China, made it difficult for Korean churches to face to face worship, therefore metaverse emerged as an alternative to solving these problems. metaverse is forming various platforms through technology expressed in 3I(Immersion, Interactive, virtual Image). The purpose of this study is to analyze the application plan of Christian education by applying metaverse technologies to Christian education. In order to achieve the purpose of this study, first, the definition, type, platform, and technology of the metaverse are presented to examine the key of the metaverse, second, in order to analyze the church from the theological educational aspect, the essence of the church, the mission of the church, and the metaverse church are examined, third in order to apply the metaverse to Christian education, it is classified into worship through the metaverse, education through the metaverse, service through the metaverse, the christian relationship through the metaverse, and missions through the metaverse. The application plan of the metaverse for Christian education is that first, worship can be held through metaverse. Second, education can be performed through the metaverse. Third, the metaverse can be used to fulfill the mission of service. Fourth, through the metaverse, christian can fellowship through the metaverse. Fifth, the missionary mission can be carried out through the metaverse. In conclusion, metaverse is still in the development stage, but various programs should be developed to achieve the purpose of Christian education by utilizing various platforms developed so far and utilizing the advantages of the platform. In particular, the Korean church will be able to utilize various programs such as Sunday worship, Sunday school, youth retreat, QT, Bible school, and pilgrimage through the metaverse to make good use of the characteristics of the metaverse. In addition, metaverse is an extended reality(XR) that integrates VR, AR, and MR, and its strength is an engagement in creative Christian educational activities out of the original Christian education. In the future, metaverse technology can be applied to Christian education in various ways as the fourth industrial technology is developing.

• Journal of the Korean earth science society
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• v.44 no.1
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• pp.13-35
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• 2023

Ocean currents play the most important role in causing and controlling global climate change. The water depth of the Yellow Sea is very shallow compared to the East Sea, and the circulation and currents of seawater are quite complicated owing to the influence of various wind fields, ocean currents, and river discharge with low-salinity seawater. The Yellow Sea Warm Current (YSWC) is one of the most representative currents of the Yellow Sea in winter and is closely related to the weather of the southwest coast of the Korean Peninsula, so it needs to be treated as important in secondary-school textbooks. Based on the 2015 revised national educational curriculum, secondary-school science and earth science textbooks were analyzed for content related to the YSWC. In addition, a questionnaire survey of secondary-school science teachers was conducted to investigate their perceptions of the temporal variability of ocean currents. Most teachers appeared to have the incorrect knowledge that the YSWC moves north all year round to the west coast of the Korean Peninsula and is strong in the summer like a general warm current. The YSWC does not have strong seasonal variability in current strength, unlike the North Korean Cold Current (NKCC), but does not exist all year round and appears only in winter. These errors in teachers' subject knowledge had a background similar to why they had a misconception that the NKCC was strong in winter. Therefore, errors in textbook contents on the YSWC were analyzed and presented. In addition, to develop students' and teachers' data literacy, class materials on the YSWC that can be used in inquiry activities were developed. A graphical user interface (GUI) program that can visualize the sea surface temperature of the Yellow Sea was introduced, and a program displaying the spatial distribution of water temperature and salinity was developed using World Ocean Atlas (WOA) 2018 oceanic in-situ measurements of water temperature and salinity data and ocean numerical model reanalysis field data. This data visualization materials using oceanic data is expected to improve teachers' misunderstandings and serve as an opportunity to cultivate both students and teachers' ocean and data literacy.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6C
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• pp.395-406
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• 2006

Drilled shafts are a common foundation solution for large concentrated loads. Such piles are generally constructed by drilling through softer soils into rock and the section of the shaft which is drilled through rock contributes most of the load bearing capacity. Drilled shafts derive their bearing capacity from both shaft and base resistance components. The length and diameter of the rock socket must be sufficient to carry the loads imposed on the pile safely without excessive settlements. The base resistance component can contribute significantly to the ultimate capacity of the pile. However, the shaft resistance is typically mobilized at considerably smaller pile movements than that of the base. In addition, the base response can be adversely affected by any debris that is left in the bottom of the socket. The reliability of base response therefore depends on the use of a construction and inspection technique which leaves the socket free of debris. This may be difficult and costly to achieve, particularly in deep sockets, which are often drilled under water or drilling slurry. As a consequence of these factors, shaft resistance generally dominates pile performance at working loads. The efforts to improve the prediction of drilled shaft performance are therefore primarily concerned with the complex mechanisms of shaft resistance development. The shaft resistance only is concerned in this study. The nature of the interface between the concrete pile shaft and the surrounding rock is critically important to the performance of the pile, and is heavily influenced by the construction practices. In this study, the influences of asperity characteristics such as the heights and angles, the strength characteristics and elastic constants of surrounding rock masses and the depth and length of rock socket, et. al. on the shaft resistance of drilled shafts are investigated from elasto-plastic analyses( FLAC). Through the parametric studies, among the parameters, the vertical stress on the top layer of socket, the height of asperity and cohesion and poison's ratio of rock masses are major influence factors on the unit peak shaft resistance.

• Journal of Korean Society of Disaster and Security
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• v.16 no.4
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• pp.45-59
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• 2023

The global focus on mitigating climate change has traditionally centered on carbon dioxide, but recent attention has shifted towards methane as a crucial factor in climate change adaptation. Natural settings, particularly aquatic environments such as wetlands, reservoirs, and lakes, play a significant role as sources of greenhouse gases. The accumulation of organic contaminants on the lake and reservoir beds can lead to the microbial decomposition of sedimentary material, generating greenhouse gases, notably methane, under anaerobic conditions. The escalation of methane emissions in freshwater is attributed to the growing impact of non-point sources, alterations in water bodies for diverse purposes, and the introduction of structures such as river crossings that disrupt natural flow patterns. Furthermore, the effects of climate change, including rising water temperatures and ensuing hydrological and water quality challenges, contribute to an acceleration in methane emissions into the atmosphere. Methane emissions occur through various pathways, with ebullition fluxes-where methane bubbles are formed and released from bed sediments-recognized as a major mechanism. This study employs Biochemical Methane Potential (BMP) tests to analyze and quantify the factors influencing methane gas emissions. Methane production rates are measured under diverse conditions, including temperature, substrate type (glucose), shear velocity, and sediment properties. Additionally, numerical simulations are conducted to analyze the relationship between fluid shear stress on the sand bed and methane ebullition rates. The findings reveal that biochemical factors significantly influence methane production, whereas shear velocity primarily affects methane ebullition. Sediment properties are identified as influential factors impacting both methane production and ebullition. Overall, this study establishes empirical relationships between bubble dynamics, the Weber number, and methane emissions, presenting a formula to estimate methane ebullition flux. Future research, incorporating specific conditions such as water depth, effective shear stress beneath the sediment's tensile strength, and organic matter, is expected to contribute to the development of biogeochemical and hydro-environmental impact assessment methods suitable for in-situ applications.

• Journal of Nutrition and Health
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• v.6 no.1
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• pp.71-76
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• 1973

1. This survey is somewhat different from that conducted by Yonsei University, although being in many respects, very similar. We found the average per capita caloric intake to be 7 or 8% of what it should be. Of that caloric intake, 84.5% in the model village here and 82.2% in the compared village Bupyong, by and large depends on cereal grains. Since such grains tend to distend the stomach, the farmers, it seems,should substitute fat for a part of their diet so as to dimish digestive pain and still receive the necessary calories. 2. Protein is the most important nutrient for the development of physical strength and improvement of health, but the average daily intake is only 68.3% of the necessary amount. It is desirable that the ratio of vegetable protein to that of animal be one to three for maintaining one's health. Most of the villager's protein, however, comes from plants: the intake of animal protein, at a level of only 13.6 g, is far below such a one to three ratio. 3. In the model village, 497.6 mg, of inorganic calcium is the daily intake level. In the compared village it is 505.5 mg, making a difference of only 8mg. This, however, is 35% less than the recommended intake. More than 50% of this calcium comes from cereals and other plants. Moreover, plant calcium which has much oxakuc acud us not as nutritional as animal calcium, so their calcium diet is less than it would appear. We must, therefore, make efforts to receive as good nutritional calcium as possible. 4. Among the vitamin group, the daily average intake of vitamin A and vitamin $B_{2}$ are respectively 40% and 32% less than the desired intake, while vitamin $B_{1}$ happens to be taken in sufficient quantities and more niacin is taken than which is even necessary. The intake of vitamin C is much more than the necessary quantity. However, this figure was calculated from uncooked food; if the loss from cooking were to be considered, the real intake might well be a little less. Also, as this survey was carried out in May, some of these results were influenced by the fact that lettuce and spinach are seasonally popular. In conclusion, except for a few nutrients which are in abundance, the normal food intake in a day is, on the whole, less than the average recommended. Furthermore despite the fact that both of these places are model villages in the development of nutrition, it seems that they have not gotten out of such conventional eating habiys as the almost dependancy on cereal grains. Cow's milk, sheep's milk, eggs and so on produced by each farmhouse are not used for their own families but are taken to the market for the purpose of making money. Accordingly, I think from now we must seek to improve, guide and enlighten the farmers as to how to correct their eating habits and implement changes in their lives so that our firm purpose may be achieved.

• Korean Journal of Agricultural Science
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• v.7 no.2
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• pp.87-102
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• 1980

In order to investigate the utilization probability of two years old laying hen for W.L. and R.I.R. breeds, carcass weight and percentage were examined and dried old chicken meat products were manufactured for experiments. The results obtained are as follows. 1. Average living body weight were 1,635.40g for the W.L. breeds and 2,289.29g for the R.I.R. breeds and percentage carcass and lean meat for the W.L. were 58.73% and 43.95%, for the R.I.R. 60.34%, 41.98%, respectively. 2. In constitution percentage of carcass on different parts for W.L. and R.I.R. breeds, head were 4.13% and 3.94%, wing 9.97% and 8.62%, breast 32.54% and 20.94%, back 11.35% and 9.75%, thigh 30.75% and 31.34%, hypordermic fat 11.37% and 17.34%, respectively. 3. In constitution percentage of lean meat on different parts for W.L. and R.I.R. breeds, head were 4.03% and 3.95%, wing 9.47% and 9.79%, breast 39.37% and 38.14%, back 11.24% and 9.40%, thigh 36.16% and 38.74%, respectively. 4. In chemical composition of old chicken meat for W.L. breed, moisture was 68.18%, crude protein 22.80%, crude fat 2.70%, extract 5.15% and crude ash 1.18% and for R.I.R. breed, moisture was 68.04%, crude protein 22.18%, crude fat 3.13%, extract 5.45% and crude ash 1.21%. 5. Weight loss in steaming for W.L. at $121^{\circ}C$ for 30min., 60min., and 90min. were 54.91, 56.43 and 58.42%, respectively, and for R.I.R. were 45.23, 47.68 and 49.68%, respectively. 6. The yield of old chicken meat product per a hen were 253.01g for W.L. and 368.64g for R.I.R., the ratio for fresh meat weight and for carcass weight were 35.47% and 26.34% for W.L. breed and 38.25 and 26.83% for R.I.R. breed. 7. In chemical composition of old chicken meat product for W.L., moisture was 16.69%, crude protein 66.16%, crude fat 12.81%, crude ash 4.35%, and R.I.R., moisture 16.11%, crude protein 65.95%, crude fat 13.78% and crude ash 4.57%. 8. To investigate the physical properties which was main factor affecting the product quality, tensile strength, tear strength and elongation rate were measured. The adhesive force of the product made under pressure of $70kg/cm^2$ was similar to those of chipo which was the control product. 9. When measured the color of each protein product, lightness of the product pressed at $70kg/cm^2$ was better than that at $35kg/cm^2$, and the lightness of breast muscle product at $70kg/cm^2$ and chipo was not significant as 16.7% and 16.4%, respectively. Dominant wavelength of product pressed at $70kg/cm^2$ was very similar to chipo which was yellowish orange. 10. In the results of sensory evaluation test containing taste, color, chewing texture and oder of the meat product, when index of chipo as control product was 100, index of breast meat product was higher than that as 118.4, but miscellaneous product was 99.7 and thigh product was 96.2. 11. Summing up the results written above, the meat product utilizing two years old laying hen was compared favorably with its similar food such as chipo on the point of nutrition and physical properties as high protein food, therefore, it was thought that industrialization must be highly appropriate.

• Economic and Environmental Geology
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• v.45 no.6
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• pp.643-659
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• 2012

The Chungju Fe-REE deposit is located in the Kyemyeongsan Formation of the Ogcheon Group. The Kyemyeongsan Formation includes meta-volcanic rocks and pegmatite hosted REE deposit which show different kind of REE-containing minerals. The meta-volcanic rocks hosted REE deposits' main REE minerals are allanite, zircon, apatite, and sphene, whereas the pegmatite hosted REE deposits is mainly composed of fergusonite, and karnasurtite, zircon, thorite. The meta-volcanic rock hosted major REE mineral is allanite as the form of aggregation and contains 23.89-29.19 wt% TREO (Total Rare Earth Oxide), 4.71-9.92 wt% $La_2O_3$, 11.30-14.33 wt% $Ce_2O_3$, 0.11-0.29 wt% $Y_2O_3$, 0.15-0.94 wt% $ThO_2$, as a formula of (Ca, Y, REE, Th)$_{2.095}$(Mg, Al, Ti, Mn, $Fe^{3+})_{2.770}(SiO_4)_{2.975}(OH)$. Accompanying REE in a coupled substitution for $Ca^{2+}$ (M1 site) and $Al^{3+}-Fe^{2+}$ (M2 site) leads to a large chemical variety. Due to the allanite's high contents of Fe, it belongs to Ferrialanite. The pegmatite hosted deposit's domi-nant REE mineral is fergusonite as prismatic or subhedral grains associated with zircon, fluorite and karnasurtite. Geochemical composition of the fergusonite($YNbO_4$) suggests substitution of Y-REE and Y-Th in A-site, and Nb-Ta-Ti in B-site, furthermore the proportion of $Y_2O_3$ and $Nb_2O_5$ is oddly 1:1.5 comparing to the ideal ratio 1:1 and Nb is higher than Y, also A-site Y actively substitutes with REE. Karnasurtite in pegmatite variously ranges 9.16-22.88 wt% $Ce_2O_3$, 2.15-9.16 wt% and $La_2O_3$, 0.44-10.8 wt% $ThO_2$, as a calculated formula (Y, REE, Th, K, Na, Ca)$_{1.478}(Ti, Nb)_{1.304}$(Mg, Al, Mn, $Fe^{3+})_{0.988}$(Si, P)$_{1.431}O_7(OH)_4{\cdot}3H_2O$. Firstly the 870-860 Ma is the initial age of the supercontinent Rhodinia dispersal and subsequent A-1 type volcanism, which contains Fe, REE, and HFS(High Field Strength elements; Nb, Zr, Y etc.) elements in Fe-rich meta-volcanic rocks dominant Kyemyeongsan Formation, might mineralized allanite. Another synthesis is that regional metamorphism at late Paleozoic 300-280 Ma(Cho et al., 2002) might cause allanite mineralization. Also pegmatite REE mineralization highly related to the granite intrusion over the Chungju area in Jurassic(190 Ma; Koh et al., 2012). Otherwise above all, A-1 type volcanism at the same time of the Kyemyeongsan Formation development, regional metamorphism and pegmatite, might have caused REE mineralization. Although REE ore bodies display a close spatial association, each ore bodies display temporal distinction, different mineral assemblage and environment of ore formation.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.3
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• pp.196-213
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• 2001

A split beam ultrasonic transducer operating at a frequency of 70 kHz to use in the fish sizing echo sounder was developed and the acoustic radiation characteristics were experimentally analyzed. The amplitude shading method utilizing the properties of the Chebyshev polynomials was used to obtain side lobe levels below -20 dB and to optimize the relationship between main beam width and side lobe level of the transducer, and the amplitude shading coefficient to each of the elements was achieved by changing the amplitude contribution of elements with 4 weighting transformers embodied in the planar array transducer assembly. The planar array split beam transducer assembly was composed of 36 piezoelectric ceramics (NEPEC N-21, Tokin) of rod type of 10 mm in diameter and 18.7 mm in length of 70 kHz arranged in the rectangular configuration, and the 4 electrical inputs were supplied to the beamformer. A series of impedance measurements were conducted to check the uniformity of the individual quadrants, and also in the configurations of reception and transmission, resonant frequency, and the transmitting and receiving characteristics were measured in the water tank and analyzed, respectively. The results obtained are summarized as follows : 1. Average resonant and antiresonant frequencies of electrical impedance for four quadrants of the split beam transducer in water were 69.8 kHz and 83.0 kHz, respectively. Average electrical impedance for each individual transducer quadrant was 49.2$\Omega$ at resonant frequency and 704.7$\Omega$ at antiresonant frequency. 2. The resonance peak in the transmitting voltage response (TVR) for four quadrants of the split beam transducer was observed all at 70.0 kHz and the value of TVR was all about 165.5 dB re 1 $\mu$Pa/V at 1 m at 70.0 kHz with bandwidth of 10.0 kHz between -3 dB down points. The resonance peak in the receiving sensitivity (SRT) for four combined quadrants (quad LU+LL, quad RU+RL, quad LU+RU, quad LL+RL) of the split beam transducer was observed all at 75.0 kHz and the value of SRT was all about -177.7 dB re 1 V/$\mu$Pa at 75.0 kHz with bandwidth of 10.0 kHz between -3 dB down points. The sum beam transmitting voltage response and receiving senstivity was 175.0 dB re 1$\mu$Pa/V at 1 m at 75.0 kHz with bandwidth of 10.0 kHz, respectively. 3. The sum beam of split beam transducer was approximately circular with a half beam angle of $9.0^\circ$ at -3 dB points all in both axis of the horizontal plane and the vertical plane. The first measured side lobe levels for the sum beam of split beam transducer were -19.7 dB at $22^\circ$ and -19.4 dB at $-26^\circ$ in the horizontal plane, respectively and -20.1 dB at $22^\circ$ and -22.0 dB at $-26^\circ$ in the vertical plane, respectively. 4. The developed split beam transducer was tested to estimate the angular position of the target in the beam through split beam phase measurements, and the beam pattern loss for target strength corrections was measured and analyzed.