The purpose of this study was to examine whether galvanic corrosion of copper occurs by inserting a third barrier layer with a higher corrosion potential than copper between copper and cast iron when the copper layer is locally perforated by pitting or partial corrosion. A triple layer composed of copper, inserted metal, and carbon steel was manufactured by cold spray coating of inserting metal powders such as Ag, Ni, and Ti on carbon steel plate followed by Cu coating on it. First, the corrosion properties were evaluated electrochemically for each metal coating. As a result of Tafel plot anaylsis in KURT groundwater condition, the corrosion potential of Fe (-567 mV) was much lower than that of Cu (-91 mV), and the corrosion potential of Ni (-150 mV) was also lower than that of Cu. Therefore, Ni was likely to corrode before Cu. However, the corrosion current of Ni was lower than that of the Cu. In the galvanic specimen where the copper and inserting metal were exposed together, Cu-Fe was much lower corrosion potential of -446 mV, and the corrosion potential of Cu-Ti, Cu-Ni, and Cu-Ag were slightly higher than that of Cu. Therefore, it seemed that Ag, Ni, and Ti all might promote galvanic corrosion of surrounding copper when the copper layer was perforated to the inserted metal layer. If the metal insertion presented in this study operates properly, the disposal container does not need to worry about the partial corrosion or non-uniform corrosion of external copper layer.
PURPOSES: In order to evaluate a crack resistance at cold joint, sealing tape was adopted to apply at cold joint instead of typical tack coat material(RSC-4). The sealing tape was made by hot sealing material. The crack resistance as function of environmental and traffic loading was measured with visual observation.
METHODS : In this study, the crack resistance was evaluated as function of environmental and traffic loading. The freeze-thaw method was adopted for environmental loading of asphalt pavement. condition. The damage of cold joint under freeze-thaw action is initiated by ice expansion load and accelerated by the interfacial damage between new and old asphalt pavement. The traffic loading was applied with wheel tracking machine on the cold joint area of the asphalt pavement for 3 hours at 25℃. The evaluation of crack resistance was measured with visual observation. The freeze-thaw results shows that the sealing tape was significantly increased the crack resistance based on.
RESULTS : To estimate the crack resistance at cold joint area due to the environmental loading, the Freeze-thaw test was conducted by exposing the product to freezing temperature(approximately -18℃) for 24 hours, and then allowing it to thaw at 60℃ for 24 hours. The tack coat material(RSC-4) was debonded after 21 cycles of the Freeze-thaw test. The first crack was observed after 14 freeze-thaw cycle with RSC-4 material. But, the sealing tape was not debonded after 24 cycle test. Also, the sealing tape shows the better performance of the crack resistance under the traffic loading with wheel track test. The crack was generated the under traffic loading with RSC-4(tack coating), however, the crack was not shown with sealing tape. It indicates that the sealing tape has a strong resistance of tensile stress due to traffic loading. CONCLUSIONS: Based on limited laboratory test result, a performance of crack resistance using the sealing tape is better than that of general tack coat material(RSC-4). It means that the sealing tape is possible to extend a pavement service life because the crack, one of the main pavement distresses, will be delayed. Keywords Sealing Tape, Crack Resistance, Freeze-Thaw, Tensile Adhesion
포도 신품종 육성에서 내한성 계통의 조기 선발을 위하여, 다양한 품종을 대상으로 randomly amplified polymorphic DNA(RAPD)를 수행하고, 그 결과를 바탕으로‘Campbell Early’x ‘Kaiji’, ‘Golden Muscat’x‘Tamnara’,‘Campbell Early’x‘Neo Muscat’와‘Alden’x‘Kaiji’의 포도교배조합 실생계통을 이용하여 내한성 관련 sequence characterized amplified region(SCAR) 분자표지를 개발하였다. 400여개의 primer를 사용하여 bulk집단에서의 RAPD 분석을 통해서 6개의 UBC random primer를 최종적으로 선발하였고, RAPD 산물을 클로닝한 후 염기서열을 분석하였다. 6개의 SCAR primer (UBC123-428, UBC196-353, UBC221-503, UBC317-800, UBC342-500, UBC344-451)를 제작하고 교배조합 실생에 재검정한 결과 내한성과 관련한 특이밴드를 확인할 수 있었다. 포도나무의 내한성과 관련한 특이적인 밴드출현양상은 수피의 탄수화물함량, 전해질전도도, 포장에서의 신초생존율과 유사한 양상을 보였다. 본 연구에서 개발한 SCAR marker는 포도의 염색체상에서 위치를 확인할 수 있었으며, 그 주변에는 주로 cytochrome P450, glutathione S-transferase, leucine-rich repeat, pleiotropic drug resistance 12, ribosomal protein 등의 유전자가 분포하였다. 본 연구에서 개발된 포도 내한성 관련 SCAR marker는 내한성 포도 품종의 조기선발과 육종효율 증진에 기여할 수 있을 것으로 기대된다.
The root crown of forage legume is an important organ which connects underground root system and aboveground branches. And its morphological characteristic is closely related to yield of grass, overwintering ability, regeneration in spring and sustainable productivity of Medicago sativa L. Therefore, in order to understand the morphological mechanism on cold resistance of the root of Melilotoides ruthenica (L.) Sojak t㏊t is a relative species of M sativa, the root morphology of different growth years' M ruthenica had been observed and analyzed. It aims to provide theoretical basis to M. sativa genetic improvement.
In this study, we determinated the dynamic changing of soluble sugar, total nitrogen and malondialdehyde, so t㏊t found out their relationships with cold resistance. The result indicates: the content of soluble sugar and total nitrogen increased from late autumn and early winter, and kept higher level during the entire winter, then decreased in regreen time in the next spring. The content of malondialdehyde was high in Sep., then decreased gradually and reached the minimum in Jan., thereafter the content of malondialdehyde represented increasing trend.
In this study, Analyzed characteristic about permeability cold-mixed recycled asphalt concrete using waste asphalt concrete and MMA. As a result, porosity was 20.4%, Water permeability coefficient was 0.94cm/sec and Skid Resistance test was 50BPN
“Baechal”, a winter wheat (Triticum aestivum L.) cultivar was developed by the National Institute of Crop Science, RDA, Iksan, Korea, during the period from 2006 to 2012. The heading and maturing dates of this variety were May 1 and June 5 in upland, and May 2 and June 8 in paddy field, respectively. It is an It is an awned, semi-dwarf and hard white wheat. Culm and spike length of “Baekchal” were 75cm and 8.7cm. It had lower test weight (794g/ℓ) and 1,000 grain weight (35.7g) than “Keumkang”. It showed moderate to pre-harvest sprouting, which lower rate of pre-harvest sprouting (13.7%) than “Keumkang”. “Baekchal” had similar ash content (0.47%) and protein content (13.1%) to “Keumkang”. It showed lower gluten content (9.6%), SDS-sedimentation volume (38.2㎖) and amylose content (6.5%) than “Keumkang”. It showed higher high viscosity (643BU), water absorption (213%), expansibility of cooking (357%). It showed different composition in HMW-GS compositios (2*), PPO18 (876bp), GBSS (waxy type) and Puroindolines composition compared th “Keumkang”. Average yield of “Baekchal” in the regional adaptation yield trial test was 4.89 ton/ha in upland and 4.83 ton/ha in paddy field. “Baekchal” would be suitable for the area above –10℃ of daily minimun temperature in January in Korean peninsula
CAX1 유전자가 도입된 형질전환 벼는 T3 세대까지 34계통을 모식물인 일품벼와 공시하였고, 그 외 종자 내 칼슘함량 조사를 비롯한 5가지 실험에서 이전에 실시한 Southern 분석 결과 CAX1 prove의 band 양상이 뚜렷이 나타난 7계 통(T-14, T-15, T-17, T-18, T-19, T-20, T-24)을 T4~T6 계통에서 공시하였다. 앞으로 T7 세대에 대한 특성조사를 거쳐 Ca2+함량이 안정적으로 높게 유지되는 계통을 선발하여 세대육성하면 칼슘과 관련된 유전자의 내재해성 작물의 기초자료 이용뿐만 아니라 농산물의 품질 고급화 및 안정성 향상 그리고 병충해에 의한 농작물 피해를 줄일 수 있는 효과를 가져 오고자 수행한 결과는 다음과 같다. T4 세대에서 형질이 안정적으로 발현되면서 모품종과 유사하고 농업적 형질이 우수한 5 계통을 선발하여 T6 세대까지 농업적인 생육 안정성(수장, 수수, 간장)은 15, 17, 18, 24 계통들은 출수기가 모품종인 일품벼와 비슷한 경향이었고 14, 19, 20계통들은 일품벼보다 6~11일까지 늦어지는 경향이었다. 형질전환체 7 계통의 간장을 조사한 결과 14 계통을 제외하고는 대부분 모품종인 일품벼와 유사하게 나타났다. CAX1 형질전환체인 T5~T6 세대에서 병저항성은 일품 모품종보다 벼도열병(blast)과 벼잎집무늬마름병(sheath blight)의 방제가가 낮게 나왔으며, 벼도열병은 2 년간 모두 모품종에 대비해 T-14, 17, 18, 19, 20은 방제가가 높게 나타나 병저항성이 있는 것으로 나타났다. 그러나 벼잎집무늬마름병은 T-14, 19, 20, 24 계통이 방제가가 높게 나타났으며, 벼도열병과 벼잎집무늬마름병 모두 방제가가 높은 계통은 T-14, 19, 20 으로 조사되었다. 저온처리 된 벼의 초장 조사에서 각각 온실과 17℃ 의 두 조건에 있어서 온실에서의 초장 조사와 생존 개체수를 대비해 볼 때 일품벼와 형질전환체 모두 정상적인 발육상태를 보였으나, 저온조건에서 초장 조사는 일품벼에 비해 T6 -19을 제외한 형질전환 계통들이 양호하였으며 T6 -18, 24 계통은 내한성 품종인 상주벼와 유사하거나 조금 차이가 났다. 종자내의 캄슘함량을 분석하기 위하여 T3~T7 종자를 이용하여 얻어진 결과는 T3 종자에서 452.2~1,376.2%로 칼슘함량이 증가되었고 분자 marker에 의해 선발하여 된 T7종자까지 분석한바 13.4~68.0%로 나타남을 확인할 수 있었다.
To investigate genes related to vernalization and cold- resistance in barley (Hordeum vulgare L. cv. Nagaoka), differentially expressed genes were identified from cold-resistant barley leaves with suppression subtractive hybridization (SSH) and Northern blot analyses. The nucleotide and the deduced amino acid sequences of the putative gene products were compared. The bvrn-7 showed high homology(84%) with gene related to vernalization, and the bvrn-3, bvrn-12, bvrn-28, bvrn-29 and bvrn-36 related to cold-resistant genes had high identity of 88~98% with low temperature-induced genes. The results indicate that the 6 genes were closely related to vernalization and cold-resistance during low temperature treatment.
Freezing-resistant plants can survive subzero temperatures by withstanding extracellular ice formation. During cold acclimation, their leaves accumulate antifreeze proteins (AFPs) that are secreted into the apoplast and have the ability to modify the normal growth of ice crystals. Three barley, two wheat and two rye cultivars were grown under two different temperature regimes (20/16~circC and 5/2~circC , day/night). Apoplastic proteins from winter cereals were separated by SDS-PAGE and detected with antisera to AFPs from winter rye. Apoplastic proteins accumulated to much higher levels in cold-acclimated (CA) leaves compared with nonacclimated (NA) ones in winter cereals. After cold acclimation, the protein concentration of apoplastic extracts increased significantly from 0.088 mgmL-1 to 0.448 mgmL-1 , with about 5-fold increment. Also, the apoplastic protein content per gram leaf fresh weight in CA leaves ranged from 31 ~mu~textrmg (gFW)-1 to 120 ~mu~textrmg (gFW)-1 with an averaged value of 77 ~mu~textrmg (gFW)-1 , and coefficients of variation of 54.9%. The CA leaves in Musketeer (a Canadian winter rye cultivar) showed the greatest AFPs and antifreeze activity followed by 'Geurumil' (a Korean winter wheat cultivar), and 'Dongbori l' (Korean facultative barley cultivar). The proteins secreted into the wheat leaf apoplast at CA condition were more numerous than those observed in winter rye, where two β -1,3-glucanase-like proteins (GLPs), two chitinase-like proteins (CLPs) and two thaumatin-like proteins (TLPs) accumulated during cold acclimation. The proteins in barley leaf apoplast at CA conditions were a little different from those in wheat leaves. The AFPs were various among and within species. More freezing-resistant cultivars had more clear and numerous bands than less freezing-resistant ones. The high determination coefficient (R2 =91 %) between freezing resistance and AFPs per gram leaf fresh weight indicated that the amount of AFPs was highly related to freezing resistance in winter cereal crops.
There are several meterorolgical stresses in the winter cereal crops. Among these stresses, cold injury is one of the most important stresses for wheat and barley production in Korea. The reduction in grain yield of the wheat and barley due to cold injury has occurred almost every year in Korea. The objective of the study was to get the basic information in relation to the cold injury and to detect the method minimizing the damage of cold injury. When the air temperature was the ranges of -13~circC to -15~circC , the soil temperature at the crown part of the plant was very stable, whereas in the ranges of -2~circC to -3~circC the soil surface temperature was more unstable and cold than air and subterranean temperatures. The different parts of the plant in wheat and barley possess the different levels of cold hardiness. In comparison to the cold hardiness of plant parts, the leaf and crown are the less sensitive to cold injury than root and vascular transitional zone. The type and extent of stress is determined by the redistribution pattern of water during freezing. These types from freezing processes were three types: a) Equilibrium freezing pattern b) Non -equilibrium freezing pattern, c) Non-equilibrium freezing pattern typical of tender tissues. Cold hardiness in wheat plants were more harder than barley plants at vegitative stage, but inverted at the reproductive stage. Injuries by low temperature during the seasons of barley cultivation in Korea were occured mainly in four stage; in the first and third stage, frost injury occurs, the second stage, freezing injury, and the fourth stage, chilling injury.