• Journal of the Korea Institute of Building Construction
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• v.16 no.5
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• pp.421-428
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• 2016

In this work, pozzolanic activities of various waste materials were compared with those of well-known by-product pozzolanic materials. Undensified and densified silica fume, ASTM class F and class C fly ash, and metakaolin were chosen as well-known pozzolanic materials, and bentonite powder, ceramic powder obtained from wash basin, and waste glass wool, which can possibly possess pozzolanic property, were chosen for comparison. Drop in electrical conductivity at $40^{\circ}C$ saturated lime solution was measured for each materials. The amount of Ca(OH)2 decomposed from cement paste at $450{\sim}500^{\circ}C$ was also measured to evaluate pozzolanic activity. The 28 day compressive strength were used to observe the mechanical property enhanced by incorporation of various waste materials. According to the experimental results, using "difference between maximum conductivity value and conductivity value at 4 hour" was found to be a reasonable approach to determine pozzolanic activity of a material. Pozzolanic activity measured using electrical conductivity correlates very well with that measured using the amount of Ca(OH)2 remained in the cement paste. Relatively good agreement was also found with electrical conductivity and 28 day compressive strength. It was found that electrical conductivity measurement can be used to evaluate pozzolanic activity of unknown materials.

• Korean journal of applied entomology
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• v.59 no.4
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• pp.341-348
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• 2020

The ATP-binding cassette (ABC) transporter superfamily represents the largest transmembrane protein that transports a variety of substrates across extra- and intra-cellular membranes. In insects, the ABC transporter proteins play crucial roles in insecticide resistance. To date, no studies have investigated the involvement of ABC transporter gene for cross-resistance to insecticide chemistries. Here, we studied such possible mechanisms against six conventional insecticides using transgenic Drosophila melanogaster strains carrying Mdr49 transcript variant A. For the 91-R and 91-C strains of Drosophila melanogaster, although they have a common origin, 91-R has been intensely selected with DDT for over 60 years, while 91-C has received no insecticide selection. Our transgenic analyses showed that overexpression of 91-R-MDR49 transcript variant A along with three amino acid variations can yield a relatively low degree of cross-resistance to carbofuran (2.0~6.7-fold) and permethrin (2.5~10.5-fold) but did not show cross-resistance to abamectin, imidacloprid, methoxychlor, and prothiofos as compared to the Gal4-driver control strain without transgene expression. These results indicate that the overexpression of Mdr49A in itself leads to a cross-resistance and three amino acid changes have additional effects on positive cross-resistance to carbofuran and permethrin.

• Biomedical Science Letters
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• v.28 no.3
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• pp.170-177
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• 2022

In mountainous regions, wild herbs which can also be edible in nature for humans and animals possess a wide array of biologically diversified properties. It is because of the fact that due to the cold weather of mountains; they are enriched in certain kinds of phytochemicals such as anti-oxidants, anti-inflammatory and many more. One such kind of an herb is Aster scaber (AS) in Korean. It is a widely cultivated culinary herb in Korean peninsula and used as a side dish in Korean culinary cuisine. In view of its extensive use in cuisine, we geared to unravel the anti-oxidant and anti-inflammatory effects of AS in murine alveolar macrophage cell line (MH-S). 2,2'-Azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) assays revealed a dose dependent (7.8~1,000 ㎍/mL) inhibition of oxidation by AS 70% ethanol (ASE) extract as compared to Trolox and Ascorbic acid respectively. Nitric oxide assay (NO) showed a dose dependent decrease (5~40 ㎍/mL) in MH-S cells with ASE when stimulated with Coal Fly Ash (CFA). Moreover, this dose for NO reduction was also found to be least cytotoxic for cells as determined by cellular viability (MTT) assay. The gene expression of pro-inflammatory mediators (iNOS and COX-2) and cytokines (IL-6 and IL-1β) and were also dose dependently inhibited by ASE in MH-S cells through RT-PCR. Therefore, in light of these findings, AS exhibited a strong anti-oxidant and anti-inflammatory agent. These results also justify the extensive use of this mountainous herb in culinary practices for beneficial effects on human health.

• Explosives and Blasting
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• v.35 no.1
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• pp.43-52
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• 2017

Mountain and hill areas occupy by more than 70% in South Korea and Rock drilling should be applied in order to reduce noisy & vibration from massive civil engineering business such as road expansion, high-way construction, subway construction and construction of site renovation such as a newly-built & re-development of apartment, newly-built of high-rising building in downtown area. As Blasting noise & vibration such as vibration, noise, fly rock etc caused by blasting operation from large small scale construction occurs, neighboring residents who demand the compensation file a civil complaint so that the business reach a deadlock. As the excavation method for these areas, There are blasting of micro-vibration, mechanical excavation method(Rock splitter, Breaker etc), similar blasting method(plasma, gel fragmentation etc) to date. In this study, we are trying to find the feature & performance which get improved economic feasibility & construct ability through improving sympathetic detonation of New KINECKER-I used in blasting of micro-vibration & formulation and would provide convenience for use by introducing standard blasting pattern & construction method. Also, checked and confirmed all the blasting with connecting cap has been cleary detonated.

• Journal of the Korean GEO-environmental Society
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• v.15 no.3
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• pp.33-40
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• 2014

In this paper, mechanical and germination characteristics of stabilized dredged soils were investigated to recycle dredged soil in eco-friendly manner such as waterfront construction. Non sintering binder (NSB), which was developed by using interchemical reactions between slag, high-calcium fly ash, alkali activator on the dredged marine clay, was added to dredged soil. Ordinary portland cement was also used for the comparison of two binders. Experimental tests such as flow test and unconfined compressive test were carried out to evaluate characteristics of stabilized dredged soil. Leaching test, pH measure, vegetation germination test were also conducted to consider environmental applicability. The unconfined compressive tests shows that unconfined compressive strength (UCS) also increases with the increase of curing time and mixed ratio. UCS of NSB mixtures were higher than those of OPC mixtures. Germination tests showed that germination and sprouting date are better in NSB mixture than OPC mixture. It can be explained that germination decreased as pH and 7-day strength increased.

• The Korean Journal of Air & Space Law and Policy
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• v.35 no.2
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• pp.3-40
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• 2020

The term "accident" in the Warsaw Convention of 1929 and the Montreal Convention of 1999, which govern carrier liability in international air transport, is an important criterion for determining carrier liability. However, because there is no explicit definition of the term in the treaty provisions, the term is largely subjected to the judgment and interpretation of the courts. Although there have been numerous changes in purpose and circumstance in the transition from the Warsaw regime to the conclusion of the Montreal Convention, there was no discussion on the concept of "accident" therefore, even after the adoption of the Montreal Convention, there is no doubt that the term is to be interpreted in the same manner as before. On this point, the United States Supreme Court's Air France v. Saks clarified the concept of "accident" and is still cited as an important precedent. Recently, the CJEU, in GN v. ZU, presented a new concept of "accident" introduced in the Montreal Convention: that "reference must be made to the ordinary meaning" in interpreting "accident" and that the term "covers all situations occurring on aboard an aircraft." Furthermore, the CJEU ruled that the term does not include the applicability of "hazards typically associated with aviation," which was controversial in previous cases. Such an interpretation can be reasonably seen as the court's expansion of the concept of "accident," with a focus on "protecting consumer interests," a core tenet of both the Montreal convention and the European Union Regulations(EC: No 889/2002). The CJEU's independent interpretation of "accident" is a departure from the Warsaw Convention and the Saks case, with their focus on "carrier protection," and instead focuses on the "passenger protection" standard of the Montreal Convention. Consequently, this expands both the court's discretion and the carrier's risk management liability. Such an interpretation by the CJEU can be said to be in line with the purpose of the Montreal Convention in terms of "passenger protection." However, there are problems to be considered in tandem with an expanded interpretation of "accident." First, there may be controversy concerning "balance" in that it focused on "passenger protection" in relation to the "equitable balance of interests" between air carriers and passengers, which is the basic purpose of the agreement. Second, huge losses are expected as many airlines fly to countries within the European Union. Third, there is now a gap in the interpretation of "accident" in Europe and the United States, which raises a question on the "unity of rules," another basic tenet of the Convention. Fourth, this interpretation of "accident" by the CJEU raises questions regarding its scope of application, as it only refers to the "hazards typically associated with aviation" and "situations occurring aboard an aircraft." In this case, the CJEU newly proposed a novel criterion for the interpretation of "accident" under the Montreal Convention. As this presents food for thought on the interpretation of "accident," it is necessary to pay close attention to any changes in court rulings in the future. In addition, it suggests that active measures be taken for passenger safety by recognizing air carriers' unlimited liability and conducting systematic reforms.

• Journal of the Korea Concrete Institute
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• v.16 no.6 s.84
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• pp.805-811
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• 2004

In this paper, effects of mixture proportion and material condition on both fundamental properties, drying and autogenous shrinkage of high performance concrete are discussed. According to the results, for the effect of mixture proportion on the fundamental properties, decrease in W/B and unit water content results in reduction of fluidity, while air content has no variation. Compressive strength exhibits an decreasing tendency with an increase in W/B and unit water content do not remarkable affect the compressive strength. For the effect of materials on the fluidity, the fluidity of low heat portland cement(LPC) is smaller than that of ordinary portland cement(OPC). The use of Polycarbonic acid based superplasticizer(PS) has more favorable effect on enhancing fluidity than Naphtalene based superplasticlzer(NS) and Melamine based superplasticizer(MS). Air content of concrete using LPC is larger than that using OPC. The effects of superplasticizer type on the air content is larger in order of MS, PS and NS. The use of LPC exhibited lower strength development at early age than OPC, whereas after 91days, similar level of compressive strength is achieved regardless of cement type. Compressive strength of concrete is not affected by SP type. For the effect of mixture proportion and materials on drying and autogenous shrinkage, an increase in W/B results in reduction of drying shrinkage and an decrease in water content leads to reduce drying shrinkage. Autogenous shrinkage is not observed until 49 days with the concrete mixture with $35\%$ of W/B and $145 kg/m^3$ of water content. This is due to the combination effects of expansion admixture and shrinkage reducing admixture, which causes an offset of autogenous shrinkage. The use of LPC results in a reduction in autogenous shrinkage compared with OPC. SP type has little influence on the autogenous shrinkage. It is found from the results that mixture proportioning of high performance concrete incorporating fly ash, silica fume, expansion admixture and shrinkage reducing admixture is need to focus on the increase in W/B and the reduction in water content and the use of LPC and MS is also required to use to secure the stability against shrinkage properties.

• Journal of Food Hygiene and Safety
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• v.32 no.1
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• pp.8-13
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• 2017

This study was conducted to develop an agent-based computing platform enabling simulation of on-farm produce contamination by enteric foodborne pathogens, which is herein called PPMCS (Preharvest Produce Microbial Contamination Simulator). Also, fecal contamination of preharvest produce was simulated using PPMCS. Although Agent-based Modeling and Simulation, the tool applied in this study, is rather popular in where socio-economical human behaviors or ecological fate of animals in their niche are to be predicted, the incidence of on-farm produce contamination which are thought to be sporadic has never been simulated using this tool. The agents in PPMCS including crop, animal as a source of fecal contamination, and fly as a vector spreading the fecal contamination are given their intrinsic behaviors that are set to be executed at certain probability. Once all these agents are on-set following the intrinsic behavioral rules, consequences as the sum of all the behaviors in the system can be monitored real-time. When fecal contamination of preharvest produce was simulated in PPMCS as numbers of animals, flies, and initially contaminated plants change, the number of animals intruding cropping area affected most on the number of contaminated plants at harvest. For further application, the behaviors and variables of the agents are adjustable depending on user's own scenario of interest. This feature allows PPMCS to be utilized in where different simulating conditions are tested.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.34 no.1
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• pp.71-82
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• 2016

Through literature review and on-site survey of Gimcheon Bangcho pavilion(芳草亭), the features of garden design(庭園意匠) including geographic conditions, landscape modeling of Nujeong(樓亭) and Jidang(池塘, Pond), and scenic interpretations in Nujeong Jeiyoung poetry(樓亭題詠詩) have been carefully researched and the findings are presented below. Bangcho pavilion is located in a village called Wonteomaeul, which belongs to the feng shui state of golden hairpin and floating lotus. It has long been the cultural hub of communication and social interactions among the villagers. The Head House of Jeongyanggong(靖襄公宗宅), the main house(本第) of the Yeonan Yi Clan(延安李氏), is about 150m away from Bangcho pavilion, an artistic space whose landscape modeling is of the form called Nujeong. The name 'Bangcho' reflects the noble man(君子)'s determination: "I yearn for the place where honey parrots fly and the fragrant grass grow." From the two story structure of the pavilion where there is an additional floor installed to the central ondol room by a four-sided subdivision door, one can detect the aspiration of the men for pursuing an open view. One can also observe the efforts in designing the room to be used for multiple purposes from a private place to an office for periodic publication of a family lineage document called "Garyejunghae(家禮增解)". Bangcho pavilion's main sight of interest is Mrs Choi's Pond(崔氏潭), the one and only garden structure that comprises the twin round island of square pond(方池雙圓島) among the existing Jidangs in Korea. In this special Jidang, there are two coexisting islands that represent a well thought out garden facility for symbolizing conjugal affection and unyielding fidelity between master and servent(主從). In addition, the three inflows and one outflow facing the Ramcheon valley is regarded as an ideal garden design optimized for performing the function of a village bangjuk which is the site for undercurrent creation and ecological reprocessing. At present, Giant pussy willow is the only circular vegetation identified in the area of Bangcho pavilion, although this plant species is about to wither away judging from the signs of decrepitude that seems to persist for two out of three weeks. The old pine tree that appears in the 1872 Jeiyoung poetry of Byeongseon Song(宋秉璿) no longer exists. Anjae(安齋) Jang Yoo(張瑠)'s "Eight Scenary on Bangcho pavilion(芳草亭八詠)" and its expansive reproduction "Ten Scenary on Bangcho pavilion(芳草亭十景)" from Gwagang(守岡) Lee Manyoung(李晩永) depict vividly the pastoric scenery of an idyll(田園景) that stretches throughout the natural and cultural landscape of the province of Gimcheon and Guseong surrounding the Bangcho pavilion. The Bangcho pavilion sutra aims to establish Bangcho pavilion and the village of Wonteomaeul as the centre of microcosmos by dividing and allocating its scenic features according to the four seasons and times(四季四時), the eight courses(八方) and the meteorological phenomena, and it is the incarnation(顯現) of landscape perception upon the Byeol-seo Scenic site of Bangcho pavilion, the cultural hub of the region.

• Economic and Environmental Geology
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• v.54 no.2
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• pp.285-297
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• 2021

Globally, nuclear-decommissioning facilities have been increased in number, and thereby hundreds of thousands of wastes, such as concrete, soil, and metal, have been generated. For this reason, there have been numerous efforts and researches on the development of technology for volume reduction and recycling of solid radioactive wastes, and this study reviewed and examined thoroughly such previous studies. The waste concrete powder is rehydrated by other processes such as grinding and sintering, and the processes rendered aluminate (C3A), C4AF, C3S, and ��-C2S, which are the significant compounds controlling the hydration reaction of concrete and the compressive strength of the solidified matrix. The review of the previous studies confirmed that waste concretes could be used as recycling cement, but there remain problems with the decreasing strength of solidified matrix due to mingling with aggregates. There have been further efforts to improve the performance of recycling concrete via mixing with reactive agents using industrial by-products, such as blast furnace slag and fly ash. As a result, the compressive strength of the solidified matrix was proved to be enhanced. On the contrary, there have been few kinds of researches on manufacturing recycled concretes using soil wastes. Illite and zeolite in soil waste show the high adsorption capacity on radioactive nuclides, and they can be recycled as solidification agents. If the soil wastes are recycled as much as possible, the volume of wastes generated from the decommissioning of nuclear power plants (NPPs) is not only significantly reduced, but collateral benefits also are received because radioactive wastes are safely disposed of by solidification agents made from such soil wastes. Thus, it is required to study the production of non-sintered cement using clay minerals in soil wastes. This paper reviewed related domestic and foreign researches to consider the sustainable recycling of concrete waste from NPPs as recycling cement and utilizing clay minerals in soil waste to produce unsintered cement.