• Computers and Concrete
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• v.30 no.6
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• pp.421-432
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• 2022

Recently, the interminable ozone depletion and the global warming concerns has led to construction industries to seek for construction materials which are eco-friendly. Regarding this, Geopolymer Concrete (GPC) is getting great interest from researchers and scientists, since it can operate by-product waste to replace cement which can lead to the reduction of greenhouse gas emission through its production. Also, compared to ordinary concrete, geopolymer concrete belongs improved mechanical and durability properties. In spite of its positive properties, the practical use of geopolymer concrete is currently limited. This is primarily owing to the scarce structural, design and application knowledge. This study investigates the Mechanical and Durability of Geopolymer Concrete Containing Fibers and Recycled Aggregate. Mixtures of elastoplastic fiber reinforced geopolymer concrete with partial replacement of recycled coarse aggregate in different proportions of 10, 20, 30, and 40% with natural aggregate were fabricated. On the other hand, geopolymer concrete of 100% natural aggregate was prepared as a control specimen. To consider both strength and durability properties and to evaluate the combined effect of recycled coarse aggregate and elastoplastic fiber, an elastoplastic fiber with the ratio of 0.4% and 0.8% were incorporated. The highest compressive strength achieved was 35 MPa when the incorporation of recycled aggregates was 10% with the inclusion of 0.4% elastoplastic fiber. From the result, it was noticed that incorporation of 10% recycled aggregate with 0.8% of the elastoplastic fiber is the perfect combination that can give a GPC having enhanced tensile strength. When specimens exposed to freezing-thawing condition, the physical appearance, compressive strength, weight loss, and ultrasonic pulse velocity of the samples was investigated. In general, all specimens tested performed resistance to freezing thawing. the obtained results indicated that combination of recycled aggregate and elastoplastic fiber up to some extent could be achieved a geopolymer concrete that can replace conventional concrete.

• Ocean and Polar Research
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• v.45 no.2
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• pp.71-87
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• 2023

Climate change causes ocean warming, ocean acidification, sea-level rise, dynamic coastal risk, change of ecosystem structure and function, and degradation of ecosystem services. Not only that, but it has negatively impacted the well-being of people, society, and culture, including food security, water resources, water quality, livelihood, health, welfare, infrastructure, transport, tourism, recreation, and so on, especially by particularly degrading indigenous communities and generating an inequitable distribution of benefits and costs. As pointed out here, these adverse impacts of climate change on the ocean have been emphasized at the international and national levels. In contrast, the ocean field has been neglected in the climate change conversation for too long. However, since the UNFCCC COP 25, the ocean has been drawn into the discussion as a solution to address climate change. Moreover, the U.S. Congress recently unveiled a bill called the 'Ocean-Based Climate Solution Act, OBCSA' that reflects the new paradigm of the international regime. The comprehensive legislative bill includes elements related to climate inequity, a blue economy, and a community-led bottom-up policy mechanism, which will have a significant bearing on the ocean-climate legal system. Therefore, this study reviews the OBCSA and deduces implications with regard to the ocean-climate legal system in Korea.

• The Journal of the Acoustical Society of Korea
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• v.41 no.6
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• pp.669-679
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• 2022

Lithium-ion battery has been used for lots of electronic devices. With the popularization of batteries, researchers have focused on batteries' electrochemical performances by environmental conditions, such as temperature, vibration, shock and charging state. Meanwhile, due to very serious global warming, car companies have started using lithium-ion batteries even in cars, replacing internal combustion engines. However, batteries have been developed based on non-moving systems which is totally different from vehicles. In the line of the differences, researchers have tried to reveal relationship between variables from dynamic systems and batteries. In this review, we discuss the comprehensive effect of vibration and shock on batteries. We firstly summarize vibration profiles and effect of normal vibration on batteries. We also sum up effect of shock and penetration on batteries and introduce how ultrasound influences on batteries. Lastly, outlook for the battery design as well as dynamic design of EVs are discussed.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.285-285
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• 2022

Recent unpredictable climate change is a major cause of rice yield loss. In particular, methane is a key factor in global warming. Therefore rice breeders are trying to breed the reducing-methane gas emission rice using the crossbreeding method. However, the traditional crossbreeding method takes 8 to 10 years to breed a cultivar, and the anther culture method developed to shorten the breeding cycle also takes 6 to 7 years. On the other hand, CRISPR/Cas9 accurately edits the target trait and can rapidly breed rice cultivars by editing the target trait as a homozygous in 2-3 years. In addition, exogenous genetic elements such as Cas9 can be isolated from the G₁ generation. Therefore, the flowering time was regulated by applying CRISPR/Cas9 technology, and OsCKq1 genome-editing (OsCKq1-G) rice with early flowered and high yield was bred in the field. Genome-editing of OsCKq1 applied CRISPR/Cas9 technology up-regulates the expression of the flowering promotion gene Ehd1 under long-day conditions induces early flowering and increases the yield by increasing the 1,000-grain weight. And as the generations advanced, each agricultural trait indicated a low coefficient of variation. As a result, indicated that OsCKq1 plays an important role in regulating the flowering time and is related to the trait determining yield. Therefore, OsCKq1-G can suggest a breeding strategy for the Net-Zero national policy for reducing-methane gas emission rice by shortening the breeding cycle with the early flowered, and high-yield rice. CRISPR/Cas9 technology is a rapid and accurate breeding technology for breeding rice cultivars with important characteristics.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.3
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• pp.239-243
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• 2007

Presence of bottom water nitrite in the Ulleung Basin was remarkable because it is totally unexpected phenomenon at such an oxygen-rich environment. Yet no scientific explanation was set forward. Of several plausible explanations, following the Ockham's suggestion, a leaching of nitrite as an intermediate product of denitrification in the top sediment at the slope is most agreeable to given environmental settings. There seems no complementary process to make up the loss of N in the Ulleung Basin, which seems contribute to the characteristically low N:P ratio in the deep waters. If warming proceeds that weakens the thermohaline circulation, a current biological pump may stall and the phytoplankton assemblage might replaced drastically. If so this will pause an utmost challenge to the ecosystem of the East/Japan Sea. Still there remains a contradictory sedimentary signature that requests further explanation regarding the N (or organic C)-cycle such as extraordinarily high organic carbon content despite abundant oxidants in the overlying waters.

• Journal of the Korean Institute of Gas
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• v.28 no.1
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• pp.53-58
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• 2024

Due to the development of industry and improvement of living standards, the amount of natural gas used in the world is constantly increasing, and related industrial facilities such as power plants, storage facilities, and supply pipelines are constantly increasing. Natural gas is a convenient and clean fuel that does not pollute the environment, but in the event of an accident due to leakage, it can cause human casualties, large-scale property damage, and negative effects on the global warming effect. In addition to the severe penalties under the Severe Disaster Punishment Act, it is necessary to ensure safety. Therefore, by applying the principle of laser-based absorption spectroscopy, we developed a long-range portable methane leakage gas detection system that can detect the concentration of methane leaking from a distance of up to 30 meters and verified its effectiveness.

• Journal of the Korean earth science society
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• v.36 no.2
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• pp.139-157
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• 2015

We investigated the relative errors of satellite-observed Surface Skin Temperature (SST) data caused by sea ice in the northern hemispheric ocean ($30-90^{\circ}N$) during April 16-24, 2003-2014 by intercomparing MODerate Resolution Imaging Spectroradiometer (MODIS) Ice Surface Temperature (IST) data with two types of Atmospheric Infrared Sounder (AIRS) SST data including one with the AIRS/Advanced Microwave Sounding Unit-A (AMSU) and the other with 'AIRS only'. The MODIS temperatures, compared to the AIRS/AMSU, were systematically up to ~1.6 K high near the sea ice boundaries but up to ~2 K low in the sea ice regions. The main reason of the difference of skin temperatures is that the MODIS algorithm used infrared channels for the sea ice detection (i.e., surface classification), while microwave channels were additionally utilized in the AIRS/AMSU. The 'AIRS only' algorithm has been developed from NASA's Goddard Space Flight Center (NASA/GSFC) to prepare for the degradation of AMSU-A by revising part of the AIRS/AMSU algorithm. The SST of 'AIRS only' compared to AIRS/AMSU showed a bias of 0.13 K with RMSE of 0.55 K over the $30-90^{\circ}N$ region. The difference between AIRS/AMSU and 'AIRS only' was larger over the sea ice boundary than in other regions because the 'AIRS only' algorithm utilized the GCM temperature product (NOAA Global Forecast System) over seasonally-varying frozen oceans instead of the AMSU microwave data. Three kinds of the skin temperatures consistently showed significant warming trends ($0.23-0.28Kyr^{-1}$) in the latitude band of $70-80^{\circ}N$. The systematic disagreement among the skin temperatures could affect the discrepancies of their trends in the same direction of either warming or cooling.

• The Journal of Internal Korean Medicine
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• v.16 no.2
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• pp.146-177
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• 1995

The purpose of this study was to investigate the relationship between the teeth and Zhang-Fu(臟腑), dental diseases, and the hygiene of the mouth through the literature of oriental medicine. First, the relatonship between the teeth and Zhang-Fu is reviewed as follows: The teeth are influenced by Shen(腎) because they are the end of bone and Biao(標) of Shen. Gingiva is related to Wei(胃) and Da-Chang(大腸) because it is passed by Yangming-Channel(陽明經). The growth and nutrition of teeth depends on Shen. The pathological condition of Shen causes the gingival atrophy, the loose of teeth, dedentition due to aging, withering of teeth, and tartar: whereas the pathological condition of Wei and Da-Chang causes toothache, gingivitis, inflamed gums, bad breath, and gingival hemorrhage. Second, the causes and therapies of dental diseases through the literature can be summarized as follows: The major causes of toothache are the pathogenic condition of wind-heat and wind-cold, the heat syndrome of Wei, the damp-heat of intestine, flaring-up of fire of deficiency type, rotten tooth, etc... The principal causes of dedentition and the shaking and loose of teeth are the deficiency of Shen, and the rest of causes are the damp-heat of Yangming. Gingival atrophy is caused by the deficiency of Shen, whereas the gingival hemorrhage comes from the factors in the pathogenic factor of wind-heat of Yangming-Channel, the heat syndrome of stomach, and the deficiency of Shen. The causes of grinding of teeth during sleeping are stomach-heat, and the delayed dentition and the withering result from the deficiency of Shen-Jing.(腎精) The principal therapies of toothache are removing wind and heat, clearing away heat and prompting diuresis, clearing away the stomach-heat, replenishing vital essence to tonify the Shen, relieving superficial syndrome by wind-cold, and alleviating pain by destroying parasites. For the prescription of the principal therapies, there are Xijio Dihuang Tang, Jiajian Ganlu Yin, Qufeng Wan, Qingwei San, Tiaowei Chenggi Tang Shengong Wan, Liangge San Qingwei Tang Yunu Jian, Liuwei Dihuang Wan Zuogui Yin Bawei Wan Wanshao Dan, Xixin San Badou Wan Gianghuo Fuzi Tang, Jiuzi Tang Badou Wan, etc... The therapies of dedentition and the shaking and loose of teeth are replenishing vital essence to tonify the Shen, and warming and recuperating the Shen-Yang: as the prescription, there are Liuwei Dihuang Wana Zuogui Yin, and Bawei Wan Anshen Wan Wanshao Dan Yougui Wan etc... The therapies of gingival hemorrhage are clearing away the stomach-heat, replenishing vital essence to tonify the Shen, warming and recuperating the Shen-Yang(腎陽), and moisturing and purging intence heat with the prescription of Tiaowei Chenggi Tang Xijiao Dihuang Tang, Liuwei Dihuang Wan Zuogui Yin, Bawei Wan Anshen Wan, and Yunu Jian. The therapy of gingival atrophy is replenishing vital essence to tonify the Shen in the prescription of Liuwei Wan Bawei Wan Ziyin Dabu Wan. The therapies of grinding of teeth during sleeping are clearing away the stomach-heat and purging intense heat, and invigorating the spleen through eliminating dampness in the prescription of Qingwei San, Wumei Wan, etc... The therapy of delaed dentition is replenishing vital essence to tonify the Shen with the prescription of Liuwei Wan Buyin Jian, etc... Third, clinical treatment reports of dental diseases are reviewed as follows: The toothache due to stomach-heat was treated by medical herbs like Gypsum, Natrir Sulfas, Rehmanniae, Schizonepetal Herba, Menthae Folium, Cimicifugae Rhizoma, and Scrophulariae Radix. The therapies of toothache due to flaring-up of fire in deficiency type from deficiency of Shen provided with replenishment of vital essence to tonify the Shen and clean ministerial fire, and the prescription was the kind of Liuwei Wan, which worked very well. The therapy of dedentition and loose of teeth due to deficiency of Shen was done to stablize the teeth as tonifing the Shen with the prescription of Guchi Wan. The rate of imrovement was over 90%. The destruction of periodontal tissue due to periodonititis was cured of dispelling wind, reducing heat, and alleviating pain, It was improved by taking Zizhi Xingiong Tang, Guchi Xiaotong San, Yunii Jian, and Qingwei San about 3-7 days, and the rate of improvement was over 80%. Fourth, the prevention and regimens are reviewed as follows: As a physical and breathing exercise of the teeth, tapping teeth which stimulates the circulation of Qi(氣) and Xue(血) had been used. The tapping time of 14, 17, 36, etc... has been reported, and it should be applied based on the body condition. The medical herbs for gargling and brushing teeth have been used. Specifically, Cimicifugae Rhizoma, Gypsum, Gypsum Fibrosum, and Indigo pulrelrata Lereis have been used to reduce heat, Coptidis Rhizama and Yang Jinggu to eliminate damp-heat, Amomi Semen, Cyperi Rhizoma, Flos Caryophylli, Asari Radix, Piperis Longi Fructus, Santali Albae Lignum, Meliae Fructus, Moschus, Aquillaiae Lignum, and Borneol to promote the circulation of Qi and to relieve pain, Ligustici Radix, Angelice Radix, Rhizoma Nardostachydis, Tribuli Semen to relieve superficial syndrome by means of diaphiresis, and Cnidii Rhizoma, Angelicae sinensis Radix, and Olibanum to promote blood circulation to stop pain.

• Microbiology and Biotechnology Letters
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• v.48 no.1
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• pp.57-63
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• 2020

Over the past 20 years, global warming has transformed the marine ecosystem of the Jeju Island into a subtropical zone making it conducive to the production of tropical fishes. Recently, the balloon fish (Diodon holoanthus) has been found off the coast of the Jeju Island. In this study, we analyzed the diversity of its intestinal microorganisms as a representative for the surrounding environment. In addition, the isolates were evaluated for their antibacterial activity. A total of 161 strains of various species were identified and isolated using 16S ribosomal RNA gene sequence analysis. They were separated into three groups, of which Phylum Proteobacteria was found to be the most dominant with 91% sequence similarity. This includes the class γ-proteobacteria that is made up of twelve genera and twenty-four hundred species. The second group comprised strains of the genus Vibrio, made up of 35% Photobacteria, 32% Shewanella, and 6% Psychrobacter. It was also determined that 4% of the isolates were Acinetobacter, 3% were Enterovibrio, while Moraxella_g2 accounted for 1% of the total isolates. Class α-proteobactera includes five genera and five species; Brevundimonas, Allorhizobium, Pseudoceanicola and Erythrobcter, each accounting for 1% of the total isolates. The Firmicute strains belonged to six genera and ten species. 5% of the strains were Terribacillus, while Paenibacillus, Salinicoccus, Staphylococcus and Streptococcus accounted for 1% each of the total isolates. Actinobacteria accounted for the final phylum with strains belonging to three genera and ten species with Janibacter, Micrococcus and Isoptericola each accounting for 1% of the total isolates.

• Ocean and Polar Research
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• v.27 no.3
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• pp.251-263
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• 2005

In order to study changes in the marine ecosystem of the East China Sea derived by the global warming and construction of the Three Gorges Dam in the middle of the Changjiang, temperature, salinity, nutrients, and chlorophyll-a were studied intensively in the northern part of the East China Sea during the summer of 2003 and spring of 2004. According to the previous studies, the upwelling of the Kuroshio Current and the Changjiang resulted in a major inputs of nutrients in the East China Sea, but these two inputs may not contribute gently to a build up of nutrients in the northern East China Sea. In spring, relatively high concentrations of nitrates and phosphates were observed in the western part of the study area, which resulted from the supply of high concentrations of nutrients showing up in the surface waters as a result of vertical mixing from the ocean bottom. The concentrations of nitrates and phosphates observed in summer were lower than those in spring, since the surface waters were well stratified by the larger discharge of fresh water from the Changjiang in summer. The surface nitrate/phosphate ratios ranged from 1.3 to 16 in spring and from 1.1 to 15 in summer and were lower than the Redfield ratio of 16, indicating that the growth of phytoplankton is limited by nitrogen. This results are contrary to the previous results, in which the growth of phytoplankton was limited by phosphate in the East China Sea. The reason for this contrary result is that most nutrients in the surface waters are supplied by vertical mixing from the bottom waters with low nitrate/phosphate ratios, not directly influenced by the Changjiang with high nitrate/phosphate ratios. The depth-integrated chlorophyll observed in summer was similar to the previous results, but those measured in spring were almost twice as high as those found in previous results. The depth-integrated chlorophyll in spring was higher than that of summer, which results from high concentrations of nitrates and phosphates in the surface waters in spring due to active vertical mixing.