• Title/Summary/Keyword: Damage spread

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Histopathological Study of Acute Toxicity of Ammonia on Common Carp Cyprinus carpio (잉어, Cyprinus carpio에 미치는 암모니아 급성독성의 조직병리학적 연구)

  • YANG Han Choon;CHUN Seh-Kyu
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.19 no.3
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    • pp.249-256
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    • 1986
  • The carp (Cyprinus carpio) used in the experiment were hatched in the spring this year and reared to 5.96g($4.84{\sim}6.55g$) in mean weight in a nursery pond at Daeyon fish farm, Pusan, Korea. The sample fish were exposed to different conditions of total ammonia (TA-N) concentrations 10, 20 and 30ppm and pH 6.5, 7.0, 7.5 and 8.0 at water temperatures 20, 25 and $30^{\circ}C$ for 24, 48 and 72 hours. After the procedure, the gill, liver and kidney of the fish were examined histopathologically. In this experiment, with the rise of water temperature, increase of pH and ammonia concentration, and the extension of exposure time the three organs showed the tendency of apparent abnormal changes such as hypertrophy and necrosis in their tissues. At $20^{\circ}C$ of water temperature gill tissue did not show any abnormality regardless of the change of pH at 10 ppm of ammonia concentration for 24 hours of exposure, but beyond the conditions given above, there occurred hypertrophy and the epithelium of gill lamellae was detached. The detach of gill lamellae epithelium initiated from the proximal part of the gill lamellae then gradually spread toward the uppermost tip. The heavier vacuolation of the liver was observed with the rise of water temperature and pH, and such morbid state in the liver was considered to be the result of edema in the liver tissue. The kidney showed no damage to the renal tubule epithelium at pH 6.5, but it was damaged at pH 8.0 when exposed to 30 ppm ammonia at $20^{\circ}C$ for 24 hours.

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Experimental and Numerical Studies on the Failure of Curtain Wall Double Glazed for Radiation Effect (커튼월 이중 유리 외장재 파단에 대한 실험 및 수치해석 연구)

  • Nam, Jiwoo;Ryou, Hong-Sun;Kim, Dong-Joon;Kim, Sung-Won;Nam, Jun-Seok;Cho, Seongwook
    • Fire Science and Engineering
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    • v.29 no.6
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    • pp.40-44
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    • 2015
  • National and international standards for curtain wall glass are focused on wind pressure and insulation performance, but disasters such as fires and earthquakes are not considered. Failure of curtain wall glass during a fire in a skyscraper increases the loss of lives and property due to the spread of fire. Therefore, the fire resistance of curtain wall glass should be investigated, and technology to prevent glass failure should be developed to prevent fire damage due to spreading fire. It is important to predict the starting point of cracks and the cause of glass failure to prevent it effectively using the limited water in a skyscraper. In this study, double glazed glass was exposed to a radiator in an experiment performed to analyze the thermal characteristics. The results show that glass that was not directly exposed to high temperature and pressure was broken. To identify this failure case, numerical analysis was performed. Three glass specimens were installed in an ISO 9705 room and exposed to radiation using a radiator, and a thermocouple was used to measure the temperature on the surface of the glass. Widely used double glazed glass was analyzed for weakness to fire.

The Real Scale Fire Test for Fire Safety in Apartment Housing (실물화재실험을 통한 공동주택의 화재안전성 연구)

  • Yoo, Yong-Ho;Kweon, Oh-Sang;Kim, Heung-Youl
    • Fire Science and Engineering
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    • v.23 no.5
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    • pp.57-65
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    • 2009
  • This study was intended to conduct a Real-scale fire test to predict the fire behavior by unit space at the apartment building where a huge casualties and injuries are likely. After setting the inflammables inside the house, the test aimed to identify the fire characteristics to each unit item was carried out. The house was divided into 4 unit space such as kitchen, living room, bedroom and a study for a real scale fire test. As a result, bedroom reached to flashover state in 5minutes after setting the fire, indicating a rapid fire growth such as 7433.3kW of maximum thermal emissivity, 578.6ppm of carbon monoxide, 1.25ppm of carbon dioxide and $1,350^{\circ}C$ of maximum indoor temperature. Particularly, the fire growth was made up to critical temperature which might cause a severe damage to the people within 3minutes, if the fire were not extinguished at inflammable space at the early stage of fire, which stressed the need of early response. The result of a real scale fire test could be compared with the outcome of expanded simulation test and used in predicting the fire spread at the space for different use.

The Efficiency Analysis of using NFC Cadastral Control Point and a Cadastral Information Application (NFC 지적기준점과 지적정보어플리케이션 적용에 대한 효용성 분석)

  • Kim, Sung Jun;Lee, Jong Dal;Kim, Sung Hun;Bae, Jae Yeol
    • Journal of Korean Society for Geospatial Information Science
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    • v.22 no.1
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    • pp.31-39
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    • 2014
  • The trend of information service and its utilization has been gradually evolving due to the technological breakthrough in IT industries and the spread of smart phones. Especially regarding smart phones, a vast array of applications are being developed and employed for the purpose of providing real time information. Recently, numerous studies have been made and applied in regards to the efficient management and the supply of cadastral control point information. This research has developed and applied the NFC Cadastral Control Point, an advanced version of QR code Cadastral Control Point, which is installed and utilized in Dong-gu Ulsan, Korea, and an application that can utilize both the QR code and the NFC. In addition, this research continues on to analyzing the utility of the two methods that the survey use of a General Cadastral Control Point and the NFC Cadastral Control Point. Having implemented both methods, NFC Cadastral Control Point outweighed its counterpart in terms of the damage it gets from the outside influence and availability. Moreover, through developing Cadastral Control Point that could apply both the QR code Cadastral Control Point and NFC Cadastral Control Point, the research saw tremendous improvements compared to the survey method using the previously existing reference point performance. The results conveyed the fact that cadastral information application was time saving, convenient, and efficient in terms of finding information. Henceforth, with government's administration over Cadastral Control Point and with the development of more application for providing information, a nation-wide monitoring of Cadastral Control Point is considered possible and an efficient usage of information service is expected as well.

TREATMENT OF COMPOSITE RESIN RESTORATION WITH THE AIR ABRASIVE TECHNIQUE (Air abrasive technique을 이용한 복합레진 수복 증례)

  • Lee, Chang-Woo;Jang, Ki-Taeg;Lee, Sang-Hoon;Hahn, Se-Hyun
    • Journal of the korean academy of Pediatric Dentistry
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    • v.24 no.4
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    • pp.763-770
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    • 1997
  • The air abrasive technique is a non-mechanical method by which teeth are treated before restoration and stains and calculi are removed from tooth surfaces using the kinetic energy of small particles. The air abrasive technique in dentistry was first introduced in the 1950's with as instrument called 'Airdent'. But, as the main restorative materials of the period were amalgam and gold, and the instrument's inability to control the flow of particles caused the particles to be spread throughout the clinics, widespread use was not possible. In the 1990's, as these techincal problems were solved and more interest in new restorative materials rose in an effort to preserve sound tooth structure, new developements took place in instruments related to the air abrasive technique. The air abrasive technique produces less pressure, vibration and heat that might cause patient discomfort and facilitates the preservation of sound tooth structure. It also reduces the need for anesthesia and is less harmful to the pulp. Other advantages include increase in dentin bonding strength of composite resin, lower possibility of saliva contamination and maintenance of a dry field. But there is not direct contact between the nozzle and the tooth, the operator cannot use his or her tactile sense and must rely solely upon visual input. Other disadvantages are: the tooth preparation depends on the operator's ability; alpha-alumina particles, after bouncing off the tooth surface, cause damage to dental mirrors; the equipment is expensive and takes up a certain amount of space in the clinic. The author conducted case report using the air abrasive technique on patient visiting the Department of Pediatric Dentistry at Seoul National University Dental Hospital and arrived at the following conclusions. 1. The tooth preparation capability of different air abrasive devices varied widely among manufacturers. 2. It was more effective in treating early caries lesions and stains compared to lesions where caries had already progressed to produce soft dentin. 3. The cold stream and noise caused by the evacuation system was a major cause of discomfort to pediatric patients. 4. As there is no direct contact with tooth surface when using the air abrasive technique for tooth preparation, considerable experience and skill is required for proper tooth preparation.

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The oriental-western literatural study of Delirious speech and Fading murmuring (섬어(語語)와 정성(鄭聲)에 대한 동서의학적(東西醫學的) 고찰(考察))

  • Choi, Byong Man;Lee, Sang Ryong
    • Journal of Haehwa Medicine
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    • v.9 no.1
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    • pp.745-761
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    • 2000
  • Literatural study for Delirious speech and Fading murmuring, the results were as follows. 1. Delirious speech and Fading murmuring are given at the speech impediment. Derious speech to be out of language's order and slur the end of his words, and Fading murmuring is to repeat in losing conscious. 2. In constrast with Delirious speech and Fading murmuring, Maniac speech is induced by a general term for manic-depressive psychosis. Luoyan is to say in a feeble voice and mumble in a sleeping condition, and Paraphasia and Solioquy are appeared in a clear mental condition. The speech impediment is caused by damages of the nervous system and speech organ, and Yuyancuoluan is appeared in a feverless condition. 3. The symptoms of Delirious speech are to utter ravings and have a loud and heavy voice, and these resemble the delirium which specially has a speech impediment and muddle in the western medical world. The symptoms of Fading murmuring are to speak ambigously, repeatedly, and illogically and so are similar to the Wernicke dysphasia which is caused by a incomprehensible conversation. 4. The causes of Delirious speech are to spread a stomach heat and the lungs pathogenic qi into heart, not to sweat in cold damage, the Three Yang Combination of syndrome, stomach repletion, yang collapse due to excessive sweat, diarrhea, after diarrhea, heat to enter the blood chamer, feces to remain in the stomach, stasis blood to enter the viscera, to carry anger to extremity, and to be constipated. the cause of Fading murmuring is to despair vacuity desertion of vital essence and energy after a serious illness. 5. The causes of delirium are general infection, postoperative states, and metabolism disorders and those of Wernicke dysphasia are disorders of the blood vessel, brain tumors and traumas. 6. Delirious speech is cured with the discrimination of vacuity and repletion. Baitong Tang(白通湯), Chaihu Guizhi Tang(柴胡桂枝湯), Chaihu Jia Longgu Muli Tang(柴胡加龍骨牡蠣湯) are prescribed in case of vacuity, while Chengqi Tang(承氣湯), Baihu Tang(白虎湯), Liangge San(凉膈散) are in case of repletion. Fading murmuring is treated with Xiao Chaihu Tang(小柴胡湯), Fuzi Tang Jiawei(附子湯加味), Shengmai San(生脈散), and Renshen Sanbai Tang(人蔘三白湯). 7. To acupunture Qimen-Xue(期門穴) is required when it is late to prescribe a medical decoction or the hyperactive liver qi attacking the spleen.

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A Design on Information Security Core Knowledge for Security Experts by Occupational Classification Framework (보안전문인력 양성을 위한 직업분류체계별 정보보호 핵심지식 설계)

  • Lee, Hyojik;Na, Onechul;Sung, Soyoung;Chang, Hangbae
    • The Journal of Society for e-Business Studies
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    • v.20 no.3
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    • pp.113-125
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    • 2015
  • Information Security Incidents that have recently happen rapidly spread and the scale of that incidents' damage is large. In addition, as it proceeds to the era of converged industry in the future environment and the virtual cyber world expands to the physical world, new types of security threats have occurred. Now, it is time to supply security professionals who have a multi-dimensional security capabilities that can manage the strategies of technological security and physical security from the management point of view, rather than the ones who primarily focus on the traditional technologic-centered strategies to solve new types of security threats. In conclusion, in this paper we try to produce the curriculum of information security featured in the occupational classification system and analyze the subjects that are additionally required for those who move to other occupations to cultivate security professionals who suited to the converged-industrial environment. It is expected that multi-dimensional security professionals who suited to the converged-industrial environment will be cultivated by harmoniously integrating information security subjects from technological and business/managerial perspectives, and education training courses will be developed that effectively provide core knowledges per occupational classification when people moves to other occupations in the areas of information security.

Investigation of Pohang Earthquake Liquefaction Using 1D Effective-Stress Site Response Analysis (1차원 유효응력개념의 지반응답해석을 통한 포항지진의 액상화 현상 규명)

  • Ahn, Jae-Kwang;Baek, Woo-Hyun;Choi, Jae-Soon;Kwak, Dong Youp
    • Journal of the Korean Geotechnical Society
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    • v.34 no.8
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    • pp.37-49
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    • 2018
  • Since the observation of ground motions in South Korea, liquefaction manifestation was the first to be observed in Pohang earthquake in 2017 with $M_L$ 5.4. Because liquefaction causes ground settlement and lateral spread damaging in-ground or super structures, various researchers have been analyzing the Pohang liquefaction case history to better understand and predict liquefaction consequence and to prevent future disasters. In prior research at the 2018 EESK conference, a map of Liquefaction Potential Index (LPI), indicating the severity of liquefaction, in Pohang was created and compared with damage observations. The LPI correlated well with the observations, but the severity categorized by LPI range was significantly higher than the actual observations in most regions. The prior LPI map was created evaluating ground motions using the simplified approach. In this research, we perform the effective site response analyses with porewater pressure generation model for the detailed evaluation of liquefaction on the liquefied sites in Pohang. We found that the simplified approach for LPI evaluation can overestimate the severity.

Study on Consideration of Artificial Rain Technology in Aspect of National Security (국가안보측면으로서의 인공강우기술 고찰)

  • Choi, Kee-Nam;Lee, Sun-Je
    • Convergence Security Journal
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    • v.12 no.2
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    • pp.99-106
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    • 2012
  • March 11, 2010, in Japan located over East Sea of Korea, due to the strong earthquake tsunami, Fukushima Nuclear Power Plant was ceased and exploded resulting in leaking radioactive substances. Even though it was an accident happened in a nation, leaked radioactive substances were spread across the world moving along ocean currents and air current. Our nation also had terror and confusion about radioactive rain after the accident, and even though a year has been passed by after the accident, the problem on the radioactive contamination isn't solved. So to speak, nuclear accident of neighboring country is a threat to our nation but not only Japan but also Chinese ocean across the West Sea has nuclear power plants. Beside threat of nuclear accident of neighboring countries, North Korea in military confrontation is the world 3rd country holding chemical and biological weapons and can spray the biological weapons to South Korea at any time like Yeonpyeong-do bombard provocation in November, 2010. The study is the strategy confronting such threats and grafted artificial rain technology which is weather control technology. Since radioactive substances on radioactive accidents and North Korean biological weapons can differ in the density by the weather condition, only artificial rain technology can remove the threat perfectly but it is worth to try as the method to reduce damage and in the aspect of psychology. To use the artificial rain technology in the aspect of national security to acquire the public safety, research institutes such ADD should fulfill active and symbolic technology research development.

A Study on Improvement of Legal System for Harmful Chemical Substance Response Management System (유해화학물질 대응시스템 적용을 위한 제도 개선 연구)

  • Oak, Young-Suk;Lee, Young-Sub
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.4
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    • pp.216-223
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    • 2017
  • Chemicals are an indispensable element of modern society to the extent that more than 15 million species are commercially available worldwide. However, among them are chemicals whose toxicityposes a threat to public health and the environment, as illustrated by past cases of chemical accidents, which revealed their danger to human life. Chemical accidents can spread and cause huge damage in a short time because of their characteristics. Therefore, it is important to do as much as possible to prevent them in advance and to respond promptly after an accident. The legal system pertaining to domestic chemical substances is the "Toxic Chemical Control Act", which is made up of the "Act on the Registration and Evaluation of Chemicals" and the "Chemical Control Act" since 2015. Under this law, the Comprehensive Chemical Information System and Chemical Substance Data Processing system were established and are still operating;however, chemical accidents are still occurring. These systems are comprehensive information systems aimed at providing chemical information rather than acting as chemical response systems, which has limited the effectiveness of accident response. This study is intended to analyze the information management systems, response management systems and the basis of chemical substance management support for hazardous chemicals and suggest ways to improve the legal system for developing and operating chemical response systemswithin a municipality.