• Title/Summary/Keyword: Sudden Rise

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Cooling and Thermal Histories of Cretaceous-Paleogene Granites from Different Fault-bounded Blocks, SE Korean Peninsula: Fission-track Thermochronological Evidences (한반도 동남부의 주단층대에 의해 구분된 지질블록별 백악기-고제3기 화강암의 차별적 냉각-지열 이력: 피션트랙 열연대학적 증거)

  • Shin, Seong-Cheon
    • The Journal of the Petrological Society of Korea
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    • v.21 no.3
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    • pp.335-365
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    • 2012
  • Fission-track (FT) thermochronological records from SE Korean Cretaceous-Paleogene granitic plutons in different fault-bounded blocks reveal contrasting cooling and later thermal histories. Overall cooling patterns are represented by a monotonous (J-shaped) curve in most plutons except some Cretaceous granites retaining a complicated (N-shaped) path due to post-reset re-cooling. Discriminative cooling rates over different temperature ranges can be explained for individual plutons with respect to relative pluton sizes, differences in initial heat loss depending on country rocks, and the presence and proximity of later igneous activity. Even within a single batholith, cooling times for different isotherms were roughly contemporaneous with respect to positions. Insignificant deviations in cooling ages from two different plutons in succession across the Yangsan fault may suggest their contemporaneity before major horizontal fault movement. The extent of later thermal rise recorded locally along the Yangsan and Dongnae fault zones were reached the Apatite Partial Stability Zone ($70-125^{\circ}C$), but did not exceed $200^{\circ}C$. Thermal alteration from fractured zones in the Yangsan-Ulsan fault junction may suggest a thermal reset above $290^{\circ}C$ resulting a complete reset in FT sphene age (31 Ma), caused by a tectonic subsidence in Early Oligocene. A consistency in FT zircon/apatite ages (24 Ma) may imply a sudden rapid cooling over $200-105^{\circ}C$, plausibly related to the abrupt tectonic uplift of the Pohang-Gampo Block including the fault junction in Late Oligocene. A remarkable trend of lower cooling ages for $300-200-100^{\circ}C$ isotherms (i.e., 19% for FT sphene and K-Ar biotite; 20% for FT zircon; 27% for FT apatite) from the east of the Ulsan fault (Pohang-Gampo Block) comparing to the west of the fault may be attributed to retarded cooling times from the Paleogene granites and also reflected by their partially-reduced apatite ages due to later thermal effects.

BREEDING OF THE PUFFER FUGU RUBRIPES (자주복 Fugu rubripes (Temminck et Schlegel)의 종묘 생산에 관한 연구)

  • PYEN Choong-Byu;RHO Bum
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.3 no.1
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    • pp.52-64
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    • 1970
  • Fingerlings hatched from the eggs of the puffer, Fugu rubripes, which were spawned on May 21, 1969, and were cultivated. The results of their growth during 150 days, until October 25th, are summarized as follows: 1. The eggs began to hatch after 163 hours, at a water temperature of 15.9 to $17.4^{\circ}C$, and the hatching rate was $61.56\%$. 2. They reached the post-larval stage 6 to 7 days after hatching, and at this time a high mortality occurred. The mortality rate was 57.26 to $68.0\%$. 3. Sixteen days after hatching some of the larger fingerlings (6.7mm in total length) began attacking some of the smaller ones (4.6mm in to total length). 4. Twenty five to twenty eight days after hatching, the fish changed their food, and at this time a second high mortality occured. The total mortality rate amounted to 90.7 to $90.9\%$ of the total hatch. 5. After the fingerling stage. cannibalism occurs. The fish usually attack the caudal part of other fingerlings. It occurs regardless of body length and when the food supply is short. 6. The food coeffiicient at the age of 46 days (when body length is 53 to 68 mm) was 5.5 for short-necked clams, 8.5 for earth-worms, and 8.7 for fishes. 7. A third hish mortality occurred 53 to 63 days after hatching, the total mortality amounting to 95.76 to $97.34\%$, and the main cause of the mortality was found to be rickets resulting from nutritional deficiency 8. The growth rates were as follows: 2.68mm just after hatching, 3.84mm at the age of 10 days; 7.96mm after 25 days; 20.96mm or 130mg after 40 days; 73.68mm or 9.06g after 80 days: and 123mm or 31.8g after 150 days. 9. The water temperature during the above period was 15.7 to $28.4^{\circ}C$ with an average of $22.10^{\circ}C$ and the salinity was 25.53 to $34.50\%$ with an average of $32.07\%$, 10. The young of this species could endure well a wide range and sudden rise in salinity, and could survive easily when the salinity suddenly fell to $5\%$, but a considerable mortality occured when it fell to $3\%$. 11. When the fish were tranferred directly to fresh water from normal sea water they died out in 9 hours and 40minutes. However, when transferred from water of $5\%$ salinity at which they were reared for 54 days, they survived for 60 hours and 40 mimutes longer than in the former case.

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Characteristics of Fatty Acid Composition and Properties by Blending of Vegetable Oils (식물성 기름의 혼합을 통한 지방산 조성 및 이화학적 특성 변화)

  • Lee, Tae Sung;Lee, Yong Hwa;Kim, Kwang Soo;Kim, Wook;Kim, Kwan Su;Jang, Young Seok;Park, Kwang Geun
    • Korean Journal of Plant Resources
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    • v.25 no.5
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    • pp.624-632
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    • 2012
  • As there have been lately many worldwide resource challenges such as potential exhaustion of fossil fuels, sudden rise of oil price and ever-rising grain pricing due to global food crisis, there have been more interests focused on recycling vegetable oils and fats into clean natural fuel and producing new resources based on waste cooking oil as a part of reusing waste resources. An Experiment was performed by using ratio of 50:50, 75:25 (w/w) mixture of based rapeseed oil, camellia oil, and olive oil. 50:50, 25:75 (w/w) mixture of based palm oil. The result was that the oleic acid ($C_{18:1}$) got the lowest percentage of 42.8%, when we combined the mixture of rapeseed oil and soybean oil. While the highest percentage of 72.1% was when the mixture of camellia oil and rapeseed oil were combined at 50:50 ratio. In 75:25 (w/w) case, mixture of rapeseed oil and soybean oil got the lowest. The highest ratio was the mixture of camellia oil and olive oil. Based on the component of palm oil, the total saturated fatty acid was decreased. It is expected that stabilizing oxidation through controlling of fatty acid after mixture and that liquidity at a low temperature. The acid value indicated that stabilizing oxidation got a range of highest to lowest. Camellia oil ranked as the highest, followed by olive oil, and the oil seeds as the lowest in rank. Controlling iodine value through mixture and improvement of stabilizing oxidation will provide a good quality. The quality of color has no significant change about mixture in ratio and maintenance. The reduction of the cost of refining process is expected by controling of mixture ratio at biodiesel production in the future.

Numerical Examinations of Damage Process on the Chuteway Slabs of Spillway under Various Flow Conditions (여수로 방류에 따른 여수로 바닥슬래브의 손상 발생원인 수치모의 검토)

  • Yoo, Hyung Ju;Shin, Dong-Hoon;Kim, Dong Hyun;Lee, Seung Oh
    • Journal of Korean Society of Disaster and Security
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    • v.14 no.4
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    • pp.47-60
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    • 2021
  • Recently, as the occurrence frequency of sudden floods due to climate variability increased, the damage of aging chuteway slabs of spillway are on the rise. Accordingly, a wide array of field survey, hydraulic experiment and numerical simulation have been conducted to find the cause of damage on chuteway slabs. However, these studies generally reviewed the flow characteristics and distribution of pressure on chuteway slabs. Therefore the derivation of damage on chuteway slabs was relatively insufficient in the literature. In this study, the cavitation erosion and hydraulic jacking were assumed to be the causes of damage on chuteway slabs, and the phenomena were reproduced using 3D numerical models, FLOW-3D and COMSOL Multiphysics. In addition, the cavitation index was calculated and the von Mises stress by uplift pressure distribution was compared with tensile and bending strength of concrete to evaluate the possibility of cavitation erosion and hydraulic jacking. As a result of numerical simulation on cavitation erosion and hydraulic jacking under various flow conditions with complete opening gate, the cavitation index in the downstream of spillway was less than 0.3, and the von Mises stress on concrete was 4.6 to 5.0 MPa. When von Mises stress was compared with tensile and bending strength of concrete, the fatigue failure caused by continuous pressure fluctuation occurred on chuteway slabs. Therefore, the cavitation erosion and hydraulic jacking caused by high speed flow were one of the main causes of damage to the chuteway slabs in spillway. However, this study has limitations in that the various shape conditions of damage(cavity and crack) and flow conditions were not considered and Fluid-Structure Interaction (FSI) was not simulated. If these limitations are supplemented and reviewed, it is expected to derive more efficient utilization of the maintenance plan on spillway in the future.

Improvement of turbid water prediction accuracy using sensor-based monitoring data in Imha Dam reservoir (센서 기반 모니터링 자료를 활용한 임하댐 저수지 탁수 예측 정확도 개선)

  • Kim, Jongmin;Lee, Sang Ung;Kwon, Siyoon;Chung, Se Woong;Kim, Young Do
    • Journal of Korea Water Resources Association
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    • v.55 no.11
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    • pp.931-939
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    • 2022
  • In Korea, about two-thirds of the precipitation is concentrated in the summer season, so the problem of turbidity in the summer flood season varies from year to year. Concentrated rainfall due to abnormal rainfall and extreme weather is on the rise. The inflow of turbidity caused a sudden increase in turbidity in the water, causing a problem of turbidity in the dam reservoir. In particular, in Korea, where rivers and dam reservoirs are used for most of the annual average water consumption, if turbidity problems are prolonged, social and environmental problems such as agriculture, industry, and aquatic ecosystems in downstream areas will occur. In order to cope with such turbidity prediction, research on turbidity modeling is being actively conducted. Flow rate, water temperature, and SS data are required to model turbid water. To this end, the national measurement network measures turbidity by measuring SS in rivers and dam reservoirs, but there is a limitation in that the data resolution is low due to insufficient facilities. However, there is an unmeasured period depending on each dam and weather conditions. As a sensor for measuring turbidity, there are Optical Backscatter Sensor (OBS) and YSI, and a sensor for measuring SS uses equipment such as Laser In-Situ Scattering and Transmissometry (LISST). However, in the case of such a high-tech sensor, there is a limit due to the stability of the equipment. Therefore, there is an unmeasured period through analysis based on the acquired flow rate, water temperature, SS, and turbidity data, so it is necessary to develop a relational expression to calculate the SS used for the input data. In this study, the AEM3D model used in the Water Resources Corporation SURIAN system was used to improve the accuracy of prediction of turbidity through the turbidity-SS relationship developed based on the measurement data near the dam outlet.

A Critical Study of the Legend on the Chinese Ancient Dynasty's Succession before Yao-Shun Era : Focusing on the Rongchengshi in the Shanghai Bowuguan zang Zhanguo Chuzhushu(II) (上海博物館蔵戦国楚竹書 《容成氏》 の古帝王帝位継承説話研究)

  • 李承律
    • Journal of the Daesoon Academy of Sciences
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    • v.17
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    • pp.197-225
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    • 2004
  • The respective history of the Chinese Ancient Dynasties from the era of the ancient Emperors to the revolutionary era of Yin-Zhou殷周 was described in the Rongchengshi容成氏, one of the texts in Shanghai Bowuguan zang Zhanguo Chuzhushu(II)上海博物館藏戰國楚竹書(二) discovered in 1994 at an antique market in Hong Kong. Drawn from the historical explanations expressed in it, the anonymous author's own views on history could be observed as largely being composed of 'resignation'禪讓, 'usurpation'簒奪, and 'banishment/smite'放伐. Following the advent of the recently excavated bamboo slips of Rongchengshi, a careful reconsideration is urgently needed to the established interpretation on the origin of the ritual of resignation in the relevant academic circles. Because it shows us that the ritual of resignation as a way of the succession, judging from my analysis, was already realized by Nine Emperors('Rongchengshi', Zunlushi尊盧氏, Hexushi赫胥氏, Gaoxinshi高辛氏, Cangjieshi倉頡氏, Xuanyuanshi軒轅氏, Shennongshi神農氏, 渾沌氏, and Baoxishi包羲氏 and maybe the more) before the era of 'Yao-Shun'堯舜. Accordingly, the aforementioned fact, which has never been elaborated in the previous texts including the first Chinese historiography Shiji史記, is the only peculiar feature to the Rongchengshi itself. Thus, a simple but empirically important question could be raised here: Was this way of description an exceptional case, even as unaccepted in Warring States Period at that time? If then, the Rongchengshi could not but help being evaluated merely as a buried historical texts, without any influence on the ancient Chinese, along with its author. The Chu bamboo slips Tangyu zhi dao唐虞之道 from Guodian Chujian郭店 excavated in 1993, however, has a very similar content to the Rongchengshi in relevance to the historical existence of the ritual of resignation. From the sentence, expressed in Tangyu zhi dao, that "the sudden rise of 'Six Emperors'六帝 was due to the practice of resignation like the period of Yao-Shun", it could be easily presumed that the 'Six Emperors' was closely connected to the 'Nine Emperors' and maybe the more at that time. Comparing with the related extant literary texts and the excavated materials in a vigorous way, in this paper, I explore four significant questions from a more critical stand to the conventional studies. First of all, I explicate the distinctiveness of the Rongchengshi as an academically very precious materials. Secondly, and closely related to the above, I evaluate its status or significance in the history of the Chinese ancient thoughts. And thirdly, I make an endeavor to trace back to the date of its transcription. Finally, and the most crucially, I attempt to show what Schools it was originated from and what connections it had with the Schools in the acient China. In sum, some concluding remarks, having somewhat insightful and significant implications for the further studies in these issues, could be drawn from my exploration. Viewing from the historical perspective of thoughts, at first, the legend of Ancient Dynasty's Succession before Yao-Shun Era in the Rongchengshi had some interactions directly and closely with Zhangzi莊子, Muzi墨子, Guanzi管子, Xunzi荀子 and Tangyu zhi dao. Also in doing search for the unification in a transitional epoch from the late to the end of the Warring States period, the political stand of Shi士 and Ke客 was reflected in it as well as in the Tangyu zhi dao because they actively wanted to suggest the most appropriate model of the Emperor or the idealistic succession process and political realms.

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The Status of North Korean Airspace after Reunification (북한 공역의 통일 후 지위)

  • Kwon, Chang-Young
    • The Korean Journal of Air & Space Law and Policy
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    • v.32 no.1
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    • pp.287-325
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    • 2017
  • Considering the development of aerospace, military science and technology since the 20th century, the sky is very important for the nation's existence and prosperity. The proverb "Whosoever commands the space commands the world itself!" emphasizes the need for the command of the air. This essay is the first study on the status of airspace after reunification. First, the territorial airspace is over the territory and territorial sea, and its horizontal extent is determined by the territorial boundary lines. Acceptance of the present order is most reasonable, rather than attempting to reconfigure through historical truths about border issues, and it could be supported by neighboring countries in the reunification period. For peace in Northeast Asia, the reunified Korea needs to respect the existing border agreement between North Korea and China or Russia. However, the North Korean straight baselines established in the East Sea and the Yellow Sea should be discarded because they are not available under United Nations Convention on the Law of the Sea. It is desirable for the reunified Korea to redefine the straight baselines that comply with international law and determine the territorial waters up to and including the 12-nautical mile outside it. Second, the Flight Information Region (hereinafter "FIR") is a region defined by the International Civil Aviation Organization (hereinafter "ICAO") in order to provide information necessary for the safe and efficient flight of aircraft and the search and rescue of aircraft. At present, Korea is divided into Incheon FIR which is under the jurisdiction of South Korea and Pyongyang FIR which is under the jurisdiction of North Korea. If North Korea can not temporarily exercise control of Pyongyang FIR due to a sudden change of circumstances, it is desirable for South Korea to exercise control of Pyongyang FIR, and if it is unavoidable, ICAO should temporarily exercise it. In reunified Korea, it is desirable to abolish Pyongyang FIR and integrate it into Incheon FIR with the approval of ICAO, considering systematic management and control of FIR, establishment of route, and efficiency of management. Third, the Air Defense Identification Zone (hereinafter "ADIZ") is a zone that requires easy identification, positioning, and control of aircraft for national security purposes, and is set up unilaterally by the country concerned. The US unilaterally established the Korea Air Defense Identification Area (KADIZ) by the Declaration of Commitment on March 22, 1951. The Ministry of Defense proclaimed a new KADIZ which extended to the area including IEODO on December 13, 2013. At present, North Korea's military warning zone is set only at maritime boundaries such as the East Sea and the Yellow Sea. But in view of its lack of function as ADIZ in relations with China and Russia, the reunified Korea has no obligation to succeed it. Since the depth of the Korean peninsula is short, it is necessary to set ADIZ boundary on the outskirts of the territorial airspace to achieve the original purpose of ADIZ. Therefore, KADIZ of the reunified Korea should be newly established by the boundary line that coincides with the Incheon FIR of the reunified Korea. However, if there is no buffer zone overlapping with or adjacent to the ADIZs of neighboring countries, military tensions may rise. Therefore, through bilateral negotiations for peace in Northeast Asia, a buffer zone is established between adjacent ADIZs.

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Herbicidal Phytotoxicity under Adverse Environments and Countermeasures (불량환경하(不良環境下)에서의 제초제(除草劑) 약해(藥害)와 경감기술(輕減技術))

  • Kwon, Y.W.;Hwang, H.S.;Kang, B.H.
    • Korean Journal of Weed Science
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    • v.13 no.4
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    • pp.210-233
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    • 1993
  • The herbicide has become indispensable as much as nitrogen fertilizer in Korean agriculture from 1970 onwards. It is estimated that in 1991 more than 40 herbicides were registered for rice crop and treated to an area 1.41 times the rice acreage ; more than 30 herbicides were registered for field crops and treated to 89% of the crop area ; the treatment acreage of 3 non-selective foliar-applied herbicides reached 2,555 thousand hectares. During the last 25 years herbicides have benefited the Korean farmers substantially in labor, cost and time of farming. Any herbicide which causes crop injury in ordinary uses is not allowed to register in most country. Herbicides, however, can cause crop injury more or less when they are misused, abused or used under adverse environments. The herbicide use more than 100% of crop acreage means an increased probability of which herbicides are used wrong or under adverse situation. This is true as evidenced by that about 25% of farmers have experienced the herbicide caused crop injury more than once during last 10 years on authors' nationwide surveys in 1992 and 1993 ; one-half of the injury incidences were with crop yield loss greater than 10%. Crop injury caused by herbicide had not occurred to a serious extent in the 1960s when the herbicides fewer than 5 were used by farmers to the field less than 12% of total acreage. Farmers ascribed about 53% of the herbicidal injury incidences at their fields to their misuses such as overdose, careless or improper application, off-time application or wrong choice of the herbicide, etc. While 47% of the incidences were mainly due to adverse natural conditions. Such misuses can be reduced to a minimum through enhanced education/extension services for right uses and, although undesirable, increased farmers' experiences of phytotoxicity. The most difficult primary problem arises from lack of countermeasures for farmers to cope with various adverse environmental conditions. At present almost all the herbicides have"Do not use!" instructions on label to avoid crop injury under adverse environments. These "Do not use!" situations Include sandy, highly percolating, or infertile soils, cool water gushing paddy, poorly draining paddy, terraced paddy, too wet or dry soils, days of abnormally cool or high air temperature, etc. Meanwhile, the cultivated lands are under poor conditions : the average organic matter content ranges 2.5 to 2.8% in paddy soil and 2.0 to 2.6% in upland soil ; the canon exchange capacity ranges 8 to 12 m.e. ; approximately 43% of paddy and 56% of upland are of sandy to sandy gravel soil ; only 42% of paddy and 16% of upland fields are on flat land. The present situation would mean that about 40 to 50% of soil applied herbicides are used on the field where the label instructs "Do not use!". Yet no positive effort has been made for 25 years long by government or companies to develop countermeasures. It is a really sophisticated social problem. In the 1960s and 1970s a subside program to incoporate hillside red clayish soil into sandy paddy as well as campaign for increased application of compost to the field had been operating. Yet majority of the sandy soils remains sandy and the program and campaign had been stopped. With regard to this sandy soil problem the authors have developed a method of "split application of a herbicide onto sandy soil field". A model case study has been carried out with success and is introduced with key procedure in this paper. Climate is variable in its nature. Among the climatic components sudden fall or rise in temperature is hardly avoidable for a crop plant. Our spring air temperature fluctuates so much ; for example, the daily mean air temperature of Inchon city varied from 6.31 to $16.81^{\circ}C$ on April 20, early seeding time of crops, within${\times}$2Sd range of 30 year records. Seeding early in season means an increased liability to phytotoxicity, and this will be more evident in direct water-seeding of rice. About 20% of farmers depend on the cold underground-water pumped for rice irrigation. If the well is deep over 70m, the fresh water may be about $10^{\circ}C$ cold. The water should be warmed to about $20^{\circ}C$ before irrigation. This is not so practiced well by farmers. In addition to the forementioned adverse conditions there exist many other aspects to be amended. Among them the worst for liquid spray type herbicides is almost total lacking in proper knowledge of nozzle types and concern with even spray by the administrative, rural extension officers, company and farmers. Even not available in the market are the nozzles and sprayers appropriate for herbicides spray. Most people perceive all the pesticide sprayers same and concern much with the speed and easiness of spray, not with correct spray. There exist many points to be improved to minimize herbicidal phytotoxicity in Korea and many ways to achieve the goal. First of all it is suggested that 1) the present evaluation of a new herbicide at standard and double doses in registration trials is to be an evaluation for standard, double and triple doses to exploit the response slope in making decision for approval and recommendation of different dose for different situation on label, 2) the government is to recognize the facts and nature of the present problem to correct the present misperceptions and to develop an appropriate national program for improvement of soil conditions, spray equipment, extention manpower and services, 3) the researchers are to enhance researches on the countermeasures and 4) the herbicide makers/dealers are to correct their misperceptions and policy for sales, to develop database on the detailed use conditions of consumer one by one and to serve the consumers with direct counsel based on the database.

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