• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.116-116
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• 2018

부식은 재료와 사용 환경과의 상호작용에 의한 결과로서 일반적으로 두께의 감소와 균열의 발생 및 파손 등의 문제로 나타난다. 특히 사용환경 중에서 해수 분위기는 금속의 부식에 가장 유리한 조건이다. 따라서 해양환경 중 항만이나 조선 및 해양 산업 등에 많이 이용되는 강 구조물은 이에 대응하기 위하여 도장방식이나 음극방식을 사용하고 있다. 여기서 음극방식은 피방식체를 일정전위로 음극 분극하는 원리로써 외부전원을 인가하거나 비전위의 금속을 전기적으로 연결하여 방식하는 방법이다[1]. 한편, 해수 중에서 이와 같은 원리로 음극방식 할 경우에는 피방식체인 강재표면에 부분적으로 칼슘 또는 마그네슘 화합물 등의 생성물이 부착하는 현상을 볼 수 있게 된다. 이와 같이 수산화마그네슘($Mg(OH)_2$)및 탄산칼슘($CaCO_3$)을 주성분으로 하여 석출되는 석회질 피막(calcareous deposits)은 피방식체에 유입되는 음극방식 전류밀도를 감소시켜 주거나 물리적 장벽의 역할을 함으로써 외부의 산소와 물 등 부식환경으로부터 소지금속을 보호한다[2]. 그러나 석회질 피막은 소지금속과의 결합력, 막의 균일한 분포, 내식성 및 제작시간의 단축 등 해결해야 할 과제가 있다. 또한 여러 가지 환경 조건 등의 영향을 받아 그 피막의 형성 정도도 가늠하기 어렵기 때문에 음극방식 설계 시 그 정도에 따른 영향을 고려-반영하기가 곤란하다. 따라서 본 연구에서는 석출속도, 밀착성 및 내식특성을 향상시키기 위해 전착프로세스를 통해 해수 중 기체를 용해시켜 석회질 피막을 제작하고 막의 결정구조 제어 및 특성을 분석-평가하였다. 본 연구에 사용된 강 기판(Steel Substrate)은 일반구조용강(KS D 3503, SS400)을 사용하였으며, 외부전원은 정류기(Rectifier, xantrex, XDL 35-5T)를 사용하여 3 및 $5A/m^2$의 조건으로 인가하였다. 양극의 경우에는 해수에 녹아있는 이온 이외에 다른 성분들이 환원되는 것을 방지하기 위해 불용성 양극인 탄소봉(Carbon Rod)을 사용하였다. 이때 석출속도, 밀착성 및 내식특성 향상을 위해 해수에 주입한 기체의 양은 0.5 NL/min였으며, 기판 근처에 고정하여 음극 부근에서의 반응을 유도하였다. 각 조건별로 제작된 막의 표면 모폴로지, 조성원소 및 결정구조 분석을 실시하였으며, 석회질 피막의 밀착성과 내식특성을 평가하기 위해 규격에 따른 테이핑 테스트(Taping Test, ISO 2409)와 3 % NaCl 용액에서 전기화학적 양극 분극 시험을 진행하여 제작된 막의 내구성과 내식성을 분석-평가하였다. 시간에 따른 전착막의 외관관찰 결과 전류밀도의 증가와 함께 상대적으로 많은 피막이 형성되었고, 용해시킨 기체에 의해 더 치밀하고 두터운 피막이 형성됨을 확인할 수 있었다. 성분 및 결정구조 분석 결과 $Mg(OH)_2$ 성분의 Brucite 및 $CaCO_3$ 성분의 Calcite 및 Aragonite 구조를 확인하였으며, 용해시킨 기체의 영향으로 $CaCO_3$ 성분의 Aragonite 구조가 상대적으로 많이 검출되었다. 밀착성 및 내식성 평가를 실시한 결과 해수 중 용해시킨 기체에 의해 제작한 시편의 경우 견고하고 화학적 친화력이 높은 Aragonite 결정이 표면을 치밀하게 덮어 전해질로부터 산소와 물의 침입을 차단하는 역할을 하여 기체를 용해시키지 않은 3 및 $5A/m^2$ 보다 비교적 우수한 밀착성 및 내식 특성을 보이는 것으로 사료된다.

• Journal of Animal Science and Technology
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• v.51 no.4
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• pp.315-320
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• 2009

This experiment was conducted to investigate the effects of dietary supplementation of fermented apple pomace (FAP) and cinnamon on performance, blood profile and meat quality in broiler chickens. A total of six hundred, day old male broiler chicks (Cobb) were randomly divided into 5 groups with 4 replicates of 30 birds each. The treatment groups were; negative control (antibiotic-free diet), positive control (basal diet with 0.05% antibiotics and 0.03% anticoccidials), FAP 1.0%, cinnamon 0.1% and FAP 1.0% + cinnamon 1.0%. The body weight of the broilers fed the diets containing FAP 1.0% was higher than the other treatments during overall period. No synergistic effect in growth performance (weight gain and feed conversion rate) was found when FAP with cinnamon were fed to broilers. No significant differences were observed on the concentration of serum blood chemical. the TBARS was lower in the chickens fed 1.0% FAP diet compared to those of negative group and positive group. These results suggest the possibility that fermented of apple pomace could be used as an alternative to antibiotic growth promoters to improve the performance and meat quality of broiler chickens.

• Korean Journal of Plant Resources
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• v.17 no.2
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• pp.94-101
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• 2004

Commercial value of soybean sprouts should be affected by their morphology including the lateral roots. This study was carried out to determine the effect of benzyladenopurine (BA) concentration on growth and morphology of soybean sprouts in order to compare them with the selling products collected from the markets. Four cultivars (cv. Eunhakong, Pungsannamulkong, Sowonkong, and Junjery) were cultured for 6 days after imbibed for 5 hours into different BA solutions (0, 1,2,4, and 8 ppm). On the 6th day, hypocotyl length was measured to calculate the composition rate of ＞ 7 cm (A), 4 to 7 cm (B), ＜ 4 cm (C) and non-germination (D), and the ratio of hypocotyl to root length (H/R ratio) on the base of hypocotyl length as well as lateral root, hypocotyl diameter, and fraction fresh and dry weights. The composition rates classified with hypocotyl length showed big differences between 4 cultivars in class A and C; Class A, in which cv. Sowonkong and Junjery had higher rates than cv. Eunhakong and Pungsannamulkong, was decreased with BA concentration of higher than 4 ppm, but class C showed the reverse result to class A. Any lateral root was not formed in higher than 4 ppm BA solutions although fewer in cv. Pungsannamulkong and Junjery than in the two other cultivars. Hypocotyl and root lengths were decreased with increased BA concentrations, and in all BA concentration, hypocotyl length of cv. Junjery was the longest. Hypocotyl diameter, hypocotyl and total fresh weights were thicker and heavier in 2 to 4 ppm BA concentrations than in the other ones, although in case of BA application, cv, Eunhakong and Sowonkong were heavier. The H/R ratios were increased with increased BA concentration. The ratios of nearly all the selling products ranged from 1 to 2 ppm when compared to them from our experiment.

• Korean Journal of Medicinal Crop Science
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• v.5 no.4
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• pp.266-275
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• 1997

Anemarrhena asphodeloides BUNGE is one of important medicinal crops, which has been collected or/and cultivated for its rhizomes. The main medicinal ingredient of the A. asphodeloides Bunge rhizomes is a saponin, which is known to have medical values for diaphoresis, sedatives and biuresis. However, studies on cultural methods and breeding works on this plant have not been made in detail. To increase productivity and to improve quality of crops, it is important to collect cultivated and wild lines, to classify them based on morphological and genetic characteristics, and to select superior pure lines at first. Therefore, total 20 A. asphodeloides lines collected were cultivated at the fieldof Chungnam Provincial Administration of Rural Development in 1995 to study the agronomic characteristics and to classify them based on morphological characteristics. Characteristics related with reproductive organ such as the number of spikes per plant and peduncle length showed greater variations than vegetative organrelated characteristics such as leaf length and rhizome length based on the coefficient of variation. Vigorous shoot growth resulted in better development of reproductive organs such as peduncle length and number of spikes per plant. However, the development of spikes was negatively correlated with chlorophyll content. Characteristics of underground parts were more significantly correlated with spike characteristics than aerial part characteristics. A. asphodeloides tested in this study were classified into 2 groups (group A and group B) based on centroid linkage cluster analysis. Group A showed more vigorous shoot growth with more leaves and spikes per plant, longer peduncle length, thicker peduncle diameter and higher shoot dry weight than group B. Group A could be further classified into 2 sub-groups based on leaf size, spike length and peduncle diameter, while group B also could be classified based on number of leaves, number of spikes and shoot dry weight.

• Korean Journal of Agricultural Science
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• v.6 no.1
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• pp.1-14
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• 1979

Selection index methods were applied to selecting better performing rice varieties with better plant characters from rice yielding trials tested under six different cultural methods. The results obtained were summarized as follows: 1. Varieties such as NO. 3, 4, 5 and 6 were selected as best performing varieties with good plant and grain characters. 2. Selection index I computed from Hazel's method was appeared effective for selecting rice varieties grown under general optimum environmental conditions, while selection index II computed from Pesek and Baker's desired genetic gain were effective for selecting rice varieties grown under rather stressed conditions. 3. The rank of mean yield of each variety was not completely in agreement with that of index values, which indicates the importance of other characters besides yield in selecting varieties. 4. Most characters studied were high in broad sense of heritabilities. 5. No significant interaction was found between varieties and cultural methods.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.5
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• pp.685-703
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• 2017

Recently, as the number of high-rise building and earthquake occurrence are increasing, it is more important to consider horizontal load such as wind and seismic loads, earth pressure, for the pile foundation. Also, development of underground space in urban areas is more demanded to meet various problem induced by growing population. Many studies on pile subjected to horizontal load have been conducted by many researchers. However, research regarding interactive behavior on pile subjected to horizontal load with tunnel are rare, so far. In this study, therefore, study on the behaviors of ground and horizontal and vertical loads applied to single pile was carried out using laboratory model test and numerical analysis. The pile axial force and ground deformation were investigated according to offset between pile and tunnel (0.0D, 1.0D, 2.0D: D = tunnel diameter). At the same time, close range photogrammetry was used to measure displacement of underground due to tunnelling during laboratory model test. The results from numerical analysis were compared to that from laboratory model test.

• Proceedings of the Mineralogical Society of Korea Conference
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• 1996.10a
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• pp.90-103
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• 1996

식물 양분으로서 유황의 중요성에 관심이 증가되고 있으며 더욱이 대기에서 유래된 유황함량이 감소되고 집약적인 농업으로 유황의 수요가 늘어나고 있다. 호주에서 유황 부족 현상이 1915에 확인된 이래 이 문제를 해결하기 위한 장기적이고 지속적인 연구가 수행되었다. 1980년까지 과석 사용으로 유황의 결핍상황은 나타나지 않았으나 작물 재배가 집약화되고 과석이 고농도비료로 대체되어 사용되면서 유황부족 현상이 증가되었다. 호주의 다우 지역에서 수행된 인광석 시험포장 30군데 중$43\%$가 2년 차에서 효과가 있었다. 토양 유황 검정사업을 통해 유황 분포상황을 파악하게 되었고 시기에 맞는 연구를 통하여 유황 비료 시용으로 유황 결핍을 극복할수 있는 비료정책 발전에 기여하게 되었다. 인도네시아에서는 유황 부족 현상은 과석과 유기질 비료 시용에서 중과석과 요소로 대체되면서 진전되었다. 쌀 생산을 위한 국가 계획에 유안을 질소로서 $25\%$ 포함시킨 효과적인 지도 활동으로 좋은 결과를 얻고 있다. 시비관리로 유황 부족 지역에 유황을 시용하는 노력을 지속하고 있다. 쌀 생산을 위한 유황비료 종류, 시용시기 및 위치 등에 관한 연구가 실용적으로 수행되고 있다. 인도네시아에서의 효과적인 종합 양분으로서의 유황 문제 해결은 연구, 지도, 행정 및 산업계의 상호 밀접한 관계를 요구하고 있다. 중국에서는 유황 부족 토양은 대기로의 유황 방출이 감소되고 고농도 비료, 저유황 비료의 시용으로 급격하게 증가되고 있다. 대부분의 중국 토양은 유황 흡수능이 낮아 생산성은 시용 유황 함량에 따라 결정된다. 유황 결핍과 양분으로서의 수지균형 관계를 이해 하므로서 농업에서의 유황 관리 체계 수립이 무엇보다 중요하다.X>$\mu\textrm{g}$ L$^{-1}$에서는 5.4%로서 가장 낮은 성장을 보였다. 성장률의 전체적인 양상은 노출농도가 증가할수록 성장이 떨어지는 결과를 보였으며, 사료효율과 마찬가지로 노출농도 80 $\mu\textrm{g}$ L$^{-1}$ 이상에서 유의한 감소를 나타냈다.circ}C$에서 각각 3.95-28.9개, 2.9-28.95개 및 1.7-13.6개로 제공된 먹이간에 차이가 현저하였다. 따라서 먹이간 성충 포식량의 현저한 차이는 기주선호성에 따른 것으로 생각된다.군에서 높았으며, elongation index(20:4$\omega$6⇒22:4$\omega$6)는 old군에서 낮았다. 대부분의 elongation과 desaturation 단계는 연령에 따라 유의한 차이를 보이지 못하였으나, $\omega$3계 지방산의 전체적 elongation-desaturation 단계를 나타내는 products-fatty acid($\omega$3)/a-LNA($\omega$3) 비율이 old군에서 young군보다 유의하게 높아, 연령에 따른 PUFA 대사의 변화가 관찰되었다. 이 상에서와 같이, 콩 단백질의 섭취로 흰쥐 혈장 인지질의 ∑MUFA조성은 낮고 ∑SFA 조성은 높아 다른 지질 강화성 분의 섭취와 유사한 결과를 나타내었다. 혈중 콜레스테롤 수준이 높은 old군에서 체내 막조직의 유동성을 유지하기 위해 PUFA의 합성 특히 $\omega$3계 지방산의 elongation-desaturation이 증가하여 총 PUFA 조성이

• Journal of the Korean Geotechnical Society
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• v.29 no.9
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• pp.43-54
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• 2013

This study proposed a new embankment stability control method to analyze the measurement data on the slope activities of the soft ground, using the Stability Control Index (SCI) obtained from the p-q stress paths. In order to validate this new technique, the data from triaxial compression tests (CU) and field measurement were compared. SCI is calculated from the current path of the effective stress points ($p^{\prime}=p-{\Delta}u$) using the relative position between the Total Stress Path $p_{max}$ and the point of $k_f$ line $p_f$. From this result, the point of effective stress $p^{\prime}(=p-{\Delta}u)$ will have access to the point $p_f$ of $k_f$ line when the pore water pressure occurs or the point of total stress pass $p^{\prime}_{max}$ when the pore pressure dissipates. Thus, the Stability Control Index (SCI) can evaluate quantitatively the safety of embankment from the relative position of the effective stress path.

• Journal of the Korean Society of Hazard Mitigation
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• v.2 no.4 s.7
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• pp.131-141
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• 2002

Precast concrete (PC) panels are often used as retaining walls to support soil pressure. In such a case, the panels should be connected at the location where PC panels meet with a buttress. However, it is not easy to provide enough development length for the reinforcing steels due to the limited width of the buttress. If it happens, the width of buttress should be increased as large enough although it is not desirable. The critical section required for providing the development length is always located where the flexural moment is maximum. Thus it is the place the buttress width ends. Also it is the place that the reinforcing steels stressed to maximum. However, it is possible to make differentiate between the maximum moment location and the most stressed location of reinforcing steels. It means that the most stressed location of reinforcing steels, the critical section, can be moved to the other place where the moment is not maximum. New critical location will have less moment than that of buttress width ends. In consequence, the development length would be longer than that of the typical way of construction. Debonding or cutting technique make it possible to reduce the moment strength of a section. Therefore reinforcing steels are debonded or cut to have a desired flexural strength at a desired place. In this study, five test specimens in full scale were erected to examine the effects of critical section movement in PC panel joints. Test parameters were the length variations of debonded and cut reinforcing steels. The test results showed that the debonding or cutting technique could be used to lengthen the development length in the joint of PC panels.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.3
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• pp.808-814
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• 2010

In this paper we executed a SBL(Short Baseline) underwater acoustic positioning system that is a kind of underwater position estimation system to estimates the 3-dimensional position of ROV(Remotely Operated Vehicle) using hydrophones and DAQ(Data Acquisition) system in the basin which dimensions are $3{\times}3{\times}1.7(m)$. For this experiment, we let 4 hydrophones in different positions of the basin for receiver and 1 hydrophone is fixed on the underwater vehicle for transmitting sensor(pinger). These five hydrophones are communicated with each other to find the 3-D positions of the moving ROV in the basin. The measured signals are collected by DAQ system and the positions of the ROV are plotted by LabView program in real-time. To estimate the position of the ROV we used a trigonometric method. In X and Y plane the estimated data has a small errors but in Z plane the estimated data has large errors so we cannot use this data for position control. One solution of this problem is using depth sensor that implemented of the underwater vehicle. Hereafter, we will test in the ocean using designed SBL system.