• Title/Summary/Keyword: bearing mechanism

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In vivo Radioprotective Effects of Basic Fibroblast Growth Factor in C3H Mice (Basic Fibroblast Growth Factor (bFGF)의 방사선보호작용에 대한 실험적 연구)

  • Kim, Yeon-Shil;Yoon, Sei-Chul
    • Radiation Oncology Journal
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    • v.20 no.3
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    • pp.253-263
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    • 2002
  • Purpose : In order to understand in vivo radiation damage modifying of bFGF on jejunal mucosa, bone marrow and the effect of bFGF on the growth of transplanted mouse sarcoma 180 tumor in mice. Materials and Methods : Mice were treated with $6\;{\mu}g$ of bFGF at 24 hours and 4 hours before exposing to 600 cGy, 800 cGy and 1,000 cGy total body irradiation (TBI), and then exposed to 3,000 cGy local radiation therapy on the tumor bearing thigh. Survival and tumor growth curve were plotted in radiation alone group and combined group of bFGF and irradiation (RT). Histologic examination was performed in another experimental group. Experimental groups consisted of normal control, tumor control, RT (radiation therapy) alone, $6\;{\mu}g$ bFGF alone, combined group of $3\;{\mu}g$ bFGF and irradiation (RT), combined group of $6\;{\mu}g$ bFGF and irradiation (RT). Histologic examination was peformed with H-E staining in marrow, jejunal mucosa, lung and sarcoma 180 bearing tumor. Radiation induced apoptosis was determined in each group with the DNA terminal transferase nick-end labeling method ($ApopTag^{\circledR}$ S7100-kit, Intergen Co.) Results : The results were as follows 1) $6\;{\mu}g$ bFGF given before TBI significantly improved the survival of lethally irradiated mice. bFGF would protect against lethal bone marrow syndrome. 2) $6\;{\mu}g$ bFGF treated group showed a significant higher crypt depth and microvilli length than RT alone group (p<0.05). 3) The bone marrow of bFGF treated group showed less hypocellularity than radiation alone group on day 7 and 14 after TBI (p<0.05), and this protective effect was more evident in $6\;{\mu}g$ bFGF treated group than that of $3\;{\mu}g$ bFGF treated group. 4) bFGF protected against early radiation induced apoptosis in intestinal crypt cell but might have had no antiapoptotic effect in bone marrow stem cell and pulmonary endothelial cells. 5) There was no significant differences in tumor growth rate between tumor control and bFGF alone groups (p>0.05). 6) There were no significant differences in histopathologic findings of lung and mouse sarcoma 180 tumor between radiation alone group and bFGF treated group. Conclusions : Our results suggest that bFGF protects small bowel and bone marrow from acute radiation damage without promoting the inoculated tumor growth in C3H mice. Improved recovery of early responding normal tissue and reduced number of radiation induced apoptosis may be possible mechanism of radioprotective effect of bFGF.

Contaminant Mechanism and Management of Tracksite of Pterosaurs, Birds, and Dinosaurs in Chungmugong-dong, Jinju, Korea (천연기념물 진주 충무공동 익룡·새·공룡발자국 화석산지의 오염물 형성 메커니즘과 관리방안)

  • Myoungju Choie;Sangho Won;Tea Jong Lee;Seong-Joo Lee;Dal-Yong Kong;Myeong Seong Lee
    • Economic and Environmental Geology
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    • v.56 no.6
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    • pp.715-728
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    • 2023
  • Tracksite of pterosaurs, birds, and dinosaurs in Chungmugong-dong in Jinju was designated as a natural monument in 2011 and is known as the world's largest in terms of the number and density of pterosaur footprints. This site has been managed by installing protection buildings to conserve in 2018. About 17% of the footprints of pterosaur, theropod, and ornithopod in this site under management in the 2nd protection building are of great academic value, but observation of footprints has difficulties due to continuous physical and chemical damage. In particular, the accumulation of milk-white contaminants is formed by the gypsum and air pollutant complex. Gypsum remains evaporated with a plate or columnar shape in the process of water circulation around the 2nd protection building, and the dust is from through the inflow of the gallery windows. The aqueous solution of gypsum, consisting of calcium from the lower bed and sulfur from grass growth, is catchmented into the groundwater from the area behind the protection building. Pollen and a few minerals other constituents of contaminants, go through the gallery window, which makes it difficult to expel dust. To conserve the fossil-bearing beds from two contaminants of different origins, controlling the water and atmospheric circulation of the 2nd protection building and removing the contaminants continuously is necessary. When cleaning contaminants, the steam cleaning method is sufficiently effective for powder-shaped milk-white contaminants. The fossil-bearing bed consists of dark gray shale with high laser absorption power; the laser cleaning method accompanies physical loss to fossils and sedimentary structures; therefore, avoiding it as much as possible is desirable.

Pullout Characteristics of MC Anchor in Shale Layer (셰일지반에 설치된 MC앵커의 인발특성)

  • Lee, Bongjik;Kim, Josoon;Lee, Jongkyu
    • Journal of the Korean GEO-environmental Society
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    • v.13 no.1
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    • pp.53-61
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    • 2012
  • In this study, the research on MC anchor has been developed as composite type has done. MC anchor exerts bearing pressure on pre-bored hole where the end fixing device is expanded. Therefore, the uplift capacity is to be increased and it has the characteristics that the anchor body is not eliminated from the ground even if the grouting is not carried out properly. Furthermore, it reduces the loss of tension and raises the construction availability by inserting the reinforced bar as well as the anchor cable, while it can improve the long-term stability because the nail is expected to play the role when the loss of the anchor cable is occurred in a long-term. However, because the resistance mechanism of the compound anchor such as MC anchor is different from friction anchor, the estimation method of the uplift capacity by the frictional force of the ground and the grout is not proper. Particularly, in domestic cases, the problem to overestimate or underestimate the uplift capacity is expected because the design method considering the soil characteristics about the compound anchor has not been developed. Therefore, in this study, in order to evaluate the characteristics of MC anchor and a kind of compound anchor, we measured the uplift, the tension and the creep by nine anchors tests in shale ground that the fluctuation of the strength is great. In addition, we analyzed the test result comparing to the result of the general friction anchor and evaluated the characteristics of MC anchor movement to gather the results. As a result of the test, we found the effect that the uplift capacity is increased in shale ground comparing to the general friction anchor.

An Analysis on Contents of Health-Concerned Editorials in Korean Neswspapers (주요일간지(主要日刊紙)의 보건의료관계사설(保健醫療關係社說) 내용분석(內容分析))

  • Kim, Byoung-Yik
    • Journal of Preventive Medicine and Public Health
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    • v.13 no.1
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    • pp.53-66
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    • 1980
  • The editorials of the leading newspapers may reflect as well as help formulate the public opinions to a significant degree. Bearing this in mind, this study was carried out to provide information useful in formulating such public health policies that could practically meet the social interests and demands in health appearing in the editorials of the newspapers. This analysis covered the editorials of 5 leading newspapers such as Donga Ilbo, Chungang Ilbo, Hankook Ilto, Chosun Ilbo and Seoul Shinmoon for about 10 years from Jan. 1st, 1970 through Oct. 31th, 1979. The major findings are as follows: 1. The total number of health-concerned editorials in the five daily papers for the period was 1,768 or occupied 6.4% of the total editorials of the same sources. The increasing trend of frequnecy of the health-concerned editorials since 1976 indicates the increment of social interests and demands in health. Analysing the contents, environmental pollution received the greatest attention in those editorials, which was followed by medical affairs, environmental sanitation, and disease control in order in terms of frequency of appearance. However, there was a tendency that the interests in the environmental pollution, medical affairs and social welfare tended to increase year by year, whereas those in environmental hygiene and disease control comparatively decreased. 2. Motives of dealing with the health-concerned editorials were provided by announcement of the governmental policies and implementation for 25.6% and by out-breaks of the relevant events for 23.9%. This tendency coincides with the general characteristics of the editorials that reflect the timely issues. Closely analysing, however, the fact that the motives engendered by the out-breaks of the relevant events or by the season concerned comparatively tended to decrease as years pass by, indicates that the editorials tend more to seek the future-oriented demands in health rather than the current issue-oriented. 3. The editorials appeared to be more concerned with the governmental policies. 95.7% of all the editorials analysed were addressed to the government. This signifies the role of government in the field of public health and medical affairs. Their attitudes toward health-related policies of the government were much more negative than the other editorials that were addressed to the government in other fields. This suggests that the governmental interests in health were neither sufficient nor fair. 4. What the editorials most stressed were; (1) increment of governmental interests in health, (2) improvement of the governmental health administration, (3) enriching the basic statistics, and (4) development of various technologies pertinent to health affairs and disease control, and so forth. However, must of their suggestions were not concrete but rather abstract and conceptual. 5. The editorials also expressed strong interests in research area. The areas of the needed research most suggested by items are; (1) development of effective health care delivery system, (2) establishment of more practical system of calculating medical cost, (3) implementation of effective policies to control degenerative diseases, (4) division of medical care services and pharmaceutical services systems, (5) effective ways to prevent Co poisoning accidents, (6) changing status of environmental pollution and its effects upon health, and (7) status of occupational diseases, and so forth. 6. There were some editorials -not small in quantity -that have risk to mislead the public opinions as well as the health policies due to lack of professional knowledge of the writers. It is desirable to establish some kind of mechanism that screens the erroneous contents of the editorials to help prevent misleading opinions.

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Shear Behavior of Reinforced Concrete Deep Beams with Web Openings (개구부를 갖는 철근콘크리트 깊은 보의 전단거동)

  • 이진섭;김상식
    • Journal of the Korea Concrete Institute
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    • v.13 no.6
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    • pp.619-628
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    • 2001
  • In building construction, openings of the story-height deep beams are usually required for accessibility and service lines such as air conditioning ducts, drain pipes and electric units. It is known that the main parameters affecting the load bearing capacity of deep beams with web openings are size, shape, location and reinforcements of openings. However, there have been no pertinent theories and national design codes for predicting ultimate shear strength of reinforced concrete deep beams with web openings. In this study, the shear behavior of simply supported reinforced concrete deep beams with web openings subject to concentrated loads has been scrutinized experimentally. A total of 34 specimens, the geometry of openings, its reinforcements and shear span to depth ratio, being taken as the experimental variables, has been cast and tested in the laboratory. The effects of these structural parameters on the shear strength and crack initiation and propagation have been carefully checked and analyzed. From the tests, it has been observed that the failures of all specimens were due to shear mechanism and the ultimate strength of specimens varies according to the location of openings, by which the formation of compression struts between the loading points and supports are deterred. All of the test results of specimens have been compared with the formulas proposed by previous researchers. The results were closely coincident with the formulas given by Ray and Kong's equation except for some X series specimens having a larger dimension of openings beyond the geometric limits of proposed equations.

Effects of Phytol and Small Water Dropwort Extract on the T Subset in the Sarcoma 180-Transplanted Mice (Phytol과 들미나리추출물이 Sarcoma 180마우스의 T Subset에 미치는 효과)

  • 김광혁;장명웅;박건영;이숙희;류태형;선우양일
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.22 no.4
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    • pp.405-411
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    • 1993
  • Several studies have shown that phytol isolated from perilla leaf and small water dropwort (Oenanthe javanica (BL) D.C., wild type) extract reveal antirumor activities. In the present study we investigated the effect of phytol and the small water dropwort extract on the T subset in the sarcoma 180-transplanted mice in order to elucidate the immunological mechanism of antiturmor activity of these substances. The results obtained from the experiment were as follows : When phytol was injected into the sarcoma-180 transplanted mice (control), the levels of T cell and T subset by inoculation of the tumor cells were enhanced, but that of T cells in case of small water dropwort extract was similar to the control. Asialo GM1$^{+}$ cells were increased when phytol or small water dropwort extract with injected into tumor-transplanted mice. In normal mice the number of asialo GM1$^{+}$ cells increased with phytol injection and decreased with small water dropwort extract injection. L3T4$^{+}$/Lyt-2$^{+}$cell ratios were decreased when phytol was injected into tumor-transplanted mire, but increased in case of small water dropwort extract injection. In normal mice the ratios showed large decreases with phytol or small water dropwort extract injection. These results indicate that phytol or small water dropwort extract ran activate the proliferation of natural killer cells that are effector cells in tumor-bearing mice.

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Root cause analysis of the abnormal wear on diesel engine crankpin and lubricant contamination (윤활유 오염과 디젤엔진의 크랭크핀 이상마모에 대한 원인 규명)

  • Seo, Jeongwoo;Park, Donghee
    • Journal of Advanced Marine Engineering and Technology
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    • v.38 no.7
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    • pp.854-867
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    • 2014
  • In the circumstance that high oil price state is continued over the world, the investment in crude oil development by oil major is a trend of increasing. Recently the number of delivered drill-ship for 5 years has been sharply increased all over the world and about twice than that of past 30 years. As addition to the increase of the drill-ship demand, the operation of drill-ships which is delivered recently is about 3,000 meters, ultra deep sea, on average and the work area is expending. Accordingly the drilling system including the size and length of pipe for drilling has been bigger and bigger and the power supply equipment for operation system also has large capacity. Unlike merchant vessel, high power and high voltage of diesel generators are required for drill-ship for which the demand for V-type 320 bore of diesel generator has increased. It is on the raised that the importance of lubrication oil cleaning for diesel generator on drill-ship which has longer time for construction, and also long term low load operation is unavoidable during commissioning of equipments. Recently it was reported that engine crankpin was damaged due to the hard contact caused by the abnormal wear down(Cam wear) on crankpin and bearing. The same pattern of wear down was found through the inspection on series vessels and the other vessel under commissioning. The purpose of this paper is to analyze of the wear mechanism based on the observation and theories and objective research from actual cases and to prepare the counter measures to avoid foreseeable damage when the lubricating oil is not properly cleaned.

Quantitative EC Signal Analysis on the Axial Notch Cracks of the SG Tubes (SG Tube 축방향 노치 균열의 정량적 EC 신호평가)

  • Min, Kyong-Mahn;Park, Jung-Am;Shin, Ki-Seok;Kim, In-Chul
    • Journal of the Korean Society for Nondestructive Testing
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    • v.29 no.4
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    • pp.374-382
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    • 2009
  • Steam generator(SG) tube, as a barrier isolating primary to the secondary coolant system of nuclear power plants(NPP), must maintain the structural integrity far the public safety and its efficient power generation capacity. And SG tubes bearing defects must be timely detected and taken repair measures if needed. For the accomplishment of these objectives, SG tubes have been periodically examined by eddy current testing(ECT) on the basis of administrative notices and intensified SG management program(SGMP). Stress corrosion cracking(SCC) on the SG tubes is not easily detected and even missed since it has lower signal amplitude and other disturbing factors against its detection. However once SCC is developed, that can cause detrimental affects to the SG tubes due to its rapid propagation rate. Accordingly SCC is categorized as prime damage mechanism challenging the soundness of the SG tubes. In this study, reproduced EDM notch specimens are examined for the detectability and quantitative characterization of the axial ODSCC by +PT MRPC probe, containing pancake, +PT and shielded pancake coils apart in a single plane around the circumference. The results of this study are assumed to be applicable fur providing key information of engineering evaluation of SCC and improvement of confidence level of ECT on SG tubes.

Remote Sensing Applications for Malaria Research : Emerging Agenda of Medical Geography (원격탐사 자료를 이용한 말라리아 연구 : 보건지리학적 과제와 전망)

  • Park, Sunyurp
    • Journal of the Korean association of regional geographers
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    • v.18 no.4
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    • pp.473-493
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    • 2012
  • Malaria infection is sensitively influenced by regional meteorological conditions along with global climate change. Remote sensing techniques have become an important tool for extraction of climatic and environmental factors, including rainfall, temperature, surface water, soil moisture, and land use, which are directly linked to the habitat qualities of malaria mosquitoes. Improvement of sensor fidelity with higher spatial and spectral resolution, new multinational sensor development, and decreased data cost have nurtured diverse remote sensing applications in malaria research. In 1984, eradication of endemic malaria was declared in Korea, but reemergence of malaria was reported in mid-1990s. Considering constant changes in malaria cases since 2000, the epidemiological management of the disease needs careful monitoring. Geographically, northmost counties neighboring North Korea have been ranked high in the number of malaria cases. High infection rates in these areas drew special attention and led to a hypothesis that malaria dispersion in these border counties might be caused by north-origin, malaria-bearing adult mosquitoes. Habitat conditions of malaria mosquitoes are important parameters for prediction of the vector abundance. However, it should be realized that malaria infection and transmission is a complex mechanism, where non-environmental factors, including human behavior, demographic structure, landscape structure, and spatial relationships between human residence and the vector habitats, are also significant considerations in the framework of medical geography.

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A Framework of Recognition and Tracking for Underwater Objects based on Sonar Images : Part 2. Design and Implementation of Realtime Framework using Probabilistic Candidate Selection (소나 영상 기반의 수중 물체 인식과 추종을 위한 구조 : Part 2. 확률적 후보 선택을 통한 실시간 프레임워크의 설계 및 구현)

  • Lee, Yeongjun;Kim, Tae Gyun;Lee, Jihong;Choi, Hyun-Taek
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.3
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    • pp.164-173
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    • 2014
  • In underwater robotics, vision would be a key element for recognition in underwater environments. However, due to turbidity an underwater optical camera is rarely available. An underwater imaging sonar, as an alternative, delivers low quality sonar images which are not stable and accurate enough to find out natural objects by image processing. For this, artificial landmarks based on the characteristics of ultrasonic waves and their recognition method by a shape matrix transformation were proposed and were proven in Part 1. But, this is not working properly in undulating and dynamically noisy sea-bottom. To solve this, we propose a framework providing a selection phase of likelihood candidates, a selection phase for final candidates, recognition phase and tracking phase in sequence images, where a particle filter based selection mechanism to eliminate fake candidates and a mean shift based tracking algorithm are also proposed. All 4 steps are running in parallel and real-time processing. The proposed framework is flexible to add and to modify internal algorithms. A pool test and sea trial are carried out to prove the performance, and detail analysis of experimental results are done. Information is obtained from tracking phase such as relative distance, bearing will be expected to be used for control and navigation of underwater robots.