• 약학회지
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• 제42권4호
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• pp.447-458
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• 1998

Inhibitory activity of pesticide-preventing active carbon fiber mask on the penetrations in pesticide spray and its inhibitory effect on acute inhalation toxicity in rats were s tudied. Pesticides were sprayed into box ($1.O{\times}1.2{\tmies}O.6\;m$) at a dose of 20ml/min of diazinon ($Diatone^{TM}$) suspension (340ppm) and 5g/min of BPMC powder (2.0%) for 4 hours, and then captured the penetrated pesticides into water via mask in box under 8l/sec suction. The pesticides were analysed by A.O.A.C. method and GC/MS. Pesticide-preventing active carbon fiber mask significantly inhibited the penetration of diazinon by 93.4% as compared with control, and cotton mask and pesticide-preventing mask did it by 74.2% and 83.7%,respectively. This result shows that pesticide-preventing active carbon fiber mask has the most prominent inhibitory effect in preventing the penetration of diazinone. In the penetration of BPMC, all of three masks, such as active carbon fiber mask, cotton mask and pesticide-preventing mask, have a similar inhibitory effect, which were 99.3%, 98.6% and 97.0%, respectively. The penetrated pesticides via pesticide-preventmg active carbon fiber mask did not exert acute inhalation toxicity.

• 한국도로학회논문집
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• 제19권2호
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• pp.7-15
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• 2017

PURPOSES : Infiltration of moisture, polluted material, and deicer into concrete, accompanied by freeze and thaw can cause significant deterioration of concrete pavement. In order to protect concrete from deterioration, it is necessary to prevent the infiltration of these concrete external materials. The moisture-repellent agent, which is a surface treatment and maintenance material added to concrete structures to render them water resistant, has advantages such as prevention of water infiltration and security against air permeation. Nano-coat, which is referred to as silicon hydride, is typically used as a moisture-repellent agent. Therefore, in this study, an attempt is made to use penetration-type Nano-coat as an alternative in order to evaluate its applicability through environmental resistance tests. METHODS : This study aimed to evaluate the applicability of penetration-type Nano-coat, which can provide water repellency to concrete, in concrete pavements, through various environmental resistance tests such as freezing and thawing resistance, chloride ion penetration resistance, and surface scaling resistance tests. The applicability of penetration-type Nano-coat was demonstrated based on the specification of KS F 2711, KS F 2456, and ASTM C 672. RESULTS :In the case of penetration-type Nano-coat applied on sound concrete, an increase in concrete durability was demonstrated by the negligible chloride ion penetrability and the absence of scaling, as revealed by visual observation of the surface, after 50 cycles of scaling resistance test. In addition, test result of the application of penetration-type Nano-coat on deteriorated concrete established that concrete surface pretreated by grinding provided improved durability than non-treated concrete. CONCLUSIONS :This study indicates that penetration-type Nano-coat is applicable as an effective alternative, to increase the durability of concrete structures. In addition, it was known that pretreatment of deteriorated concrete surface, such as grinding, is required to improve the long-term performance of concrete pavement.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.313-316
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• 2006

The most serious cause of deterioration in the concrete structures is reinforcing corrosion due to the chloride attack and carbonation. Therefore, it is needed to protect durability and performance according to the appropriate materials and methods in the concrete structures. In general, several types of polymer and silicate are used as protecting deterioration agents of concrete structures, but these agents have many problems because of low durability and properties. The object of this study is to develop a preventing aging technology. The work involves the development of silicate type penetration reinforcing agent.

• Journal of Welding and Joining
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• 제26권4호
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• pp.44-49
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• 2008

Generally, wear plate is steel plate having improved surface contact strength and impact strength by surface hardening which is welded using materials with good corrosion resistance, wear resistance and thermal resistance property. CFP GMAW(Compound Filler Plate Gas Metal Arc Welding) is the cladding method using GMAW with the CFP, which is bound with waterglass, on the substrate. It has advantages of reducing compound powder loss, uniform penetration, and preventing hardness decrease. To develope mass production technique of CFP GMAW process for production of high quality wear plate, the method for controling shallow penetration and increasing productivity is required. In this study, twin torch method applied to CFP GMAW process for increasing productivity. And the method was developed by controling penetration control, CFP dry time, gas formation flux and water glass concentration. As a result, applying twin torch method to CFP GMAW process was possible and high quality wide bead could be made without overlap joint.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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• pp.297-300
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• 2003

A chloride is an important deteriorating factor which governs the durability of the reinforced-concrete structures under marine environments. Also, the main penetration mechanism of chloride ion into concrete is a diffusion phenomenon. In this study, It is evaluated the diffusion coefficient of chloride ion in non-steady state by Fick's second law. Submergence method in salt water carried out in this experiment. Two types of cement which is different in mineral composition were used. In addition, the effect of mineral admixtures of blast-furnace slag and meta-kaolin was studied. In conclusion, the diffusion coefficient of chloride ion is much affected according to cement type and mineral admixtures, also, it is proved that meta-kaolin as well as blast-furnace slag is effective in preventing penetration of chloride ion.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.90-95
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• 2004

In this study, we proposed new method to mitigate tensile welding residual stress for preventing PWSCC in CRDM nozzle. Residual stress analysis using finite element method is performed to confirm benefit of the new method. In case of applying existing method, tensile axial residual stress decrease by about 28% and tensile hoop residual stress decrease by about 33%. In case of applying the new method, tensile axial residual stress decrease by about 32% and tensile hoop residual stress decrease by about 43%. Therefore, we conclude the new proposed method is more effective to prevent PWSCC than existing method.

• 한국건축시공학회지
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• 제15권2호
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• pp.185-192
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• 2015

기존 교량의 신축이음장치는 각종 노후화로 인해 제설제를 포함한 노면수의 누수사례가 빈번히 발생하여 교량의 수명을 감소시켜 유지관리 비용을 가중시킨다. 이러한 문제점을 해결하기 위해 신축이음장치를 사용하지 않는 고인성 연결조인트 공법을 개발하였으며, 본 연구에서는 개발된 고인성 연결조인트공법의 균열제어성능 균열 후 누수방지성능 및 염해저항성을 실험적으로 검토하였다. 그 결과, 연결조인트 소재에서 PCM, FRC를 사용한 경우에는 균열 분산성이 불량해서 누수 및 염해가 쉽게 발생하였다. 반면, 고인성 콘크리트를 사용한 연결조인트는 인장변형량이 최대 7.5mm까지 균열을 무해한 마이크로 크랙으로 안정적으로 분산시켰으며, 가혹한 조건에서도 누수를 방지할 수 있었다. 또한, 균열 후에도 염화물 이온의 침투를 방지하여 염해저항성을 확보할 수 있었다.

• 한국지역지리학회지
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• 제16권1호
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• pp.34-47
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• 2010

본 연구는 택지개발지구 내 단독주택용지의 상업용도의 침투 실태를 파악하고, 상업용도 침투요소의 영향력을 분석함으로써 향후 단독주택용지의 효율적인 개발방안을 도출하는데 목적이 있다. 분석결과 첫째, 도로특성 중 개별필지와 접하고 있는 도로의 폭원이 클수록 상업용도 침투에 영향을 미치는 것으로 나타났다. 이는 비주거시설이 교통접근성이 양호한 지역을 선호하여 이용객의 이용빈도가 높아지는 도로와 접해있는 지역에 입지하려는 성향이 있음을 보여준다. 둘째, 주변용도특성 중 단독주택용지, 공동주택, 근련생활시설, 학교와외 거리는 단독주택용지와 가까울수록 상업용도 침투비율의 상승 요인으로 작용하는 것으로 분석되었다. 이와 반대로 공원과의 거리는 멀수록 상업용도 침투비율이 높아지는 것으로 나타났다. 이는 곧 순수단독주택이 쾌적한 환경의 조건아라 할 수 있는 공원과 가까운 곳에 인접하여 조성되어 있고, 상업용도의 침투를 밀어내는 요소로 분석된다. 셋째, 지가특성온 양의 행태를 나타냈는데 이는 곧 공시지가의 가격이 높을수록 상업용도의 침투비율을 상승시키는 요인으로 작용하는 것으로 분석되었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.2020-2022
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• 2000

The cross-linked polyethylene(herein after XLPE) insulated power cable emit the methane($CH_4$)gas in the course of chemical cross-linking process. The general stranded conductor easily discharge this methane gas through the gap of each stranded wires. But the special stranded conductor that filled with semi-conducting rubber compound to prevent water penetration which is applied to water proof type of cable(22.9kV CN/CV-W), disturb the methane gas emission. The pre-mold type cable joint shall be expanded gradually by emit of gas left in XLPE insulation. For example, sometimes the corona problem outbreak on a new power distribution line, resulted from the gap between the sleeve and semi-conductive layer of cable joint. If above mentioned problem especially happened on the way of operating. We have to shut down the line and try to discharge the methane gas in cable joint. In this point, we would like to explain the mechanism of methane gas & cable joint and our test result briefly. At last, we are pleased to introduce the solution for preventing reoccurrence of this problem.

• 한국환경농학회지
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• 제42권2호
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• pp.104-111
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• 2023

As apple trees mature, it is important to maintain good light distribution within the canopy to produce marketable fruits. Tree thinning is the selective removal of a proportion of trees growing in the orchard to provide more growing space and a good light environment for the remaining trees. This study was conducted over 3 years (14-16 years after planting) to investigate the influence of tree thinning on vegetative growth, yield, fruit quality, and blooming in the 14 years old slender spindle 'Fuji'/M.9 apple trees planted with the tree space of 3.2×1.2 m. The trees were placed in a control group (no thinning; 260 trees per 10 a) or a tree thinning group (thinned 50% of the control; 130 trees per 10 a). The tree thinning successfully improved light penetration, yield per tree, fruit red color, and yield efficiency for 3 years, and the tree thinning controlled the occurrence of biennial bearing. However, tree thinning significantly decreased accumulated yield per 10 a compared with the control. The vegetative growth, yield per tree, soluble solid contents, and blooming were not clear by the occurrence of biennial bearing in the control. These results indicated that tree thinning was a good method for improving light penetration and preventing biennial bearing in the old 'Fuji'/M.9 high-density apple orchards.