• Title/Summary/Keyword: Damage spread

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Evaluation of Rutting Resistance and Moisture Sensitivity of Warm-Mix Asphalt Mixtures Using the Model Mobile Loading Simulator(MMLS3) (소형 포장 가속시험기를 이용한 중온 아스팔트 혼합물의 소성변형저항성 및 수분민감도 평가)

  • Lee, Jae-Jun;Kim, Yong-Joo;Yang, Sung-Lin;Kwon, Soo-Ahn;Hwang, Sung-Do
    • International Journal of Highway Engineering
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    • v.13 no.2
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    • pp.41-48
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    • 2011
  • Warm-mix asphalt(WMA) technology has been developed to allow asphalt mixtures to be produced and compacted at a significantly lower temperature. The WMA technology was identified as one of means to lower emissions for $CO_2$ and has been spread so quickly in the world. Recently, two innovative WMA additives has been developed to reduce mixing and paving temperatures applied in asphalt paving process in Korea. Since the first public demonstration project in 2008, many WMA projects have successfully been constructed in national highways. In 2010, the WMA field trial was conducted on new national highway construction under Dae-Jeon Regional Construction Management Administration. The two different WMA loose mixtures(WMA and WMA-P) and a HMA mixture were collected at the asphalt plant to evaluate their mechanical performance in the laboratory. The Third-scale Model Mobile Loading Simulator(MMLS3) was adopted to evaluate rutting resistance and moisture damage under different traffic and environmental conditions. In this study, plant-produced WMA mixtures using two WMA additives along with the conventional hot mix asphalt(HMA) mixtures were evaluated with respect to their rutting resistance and moisture susceptibility using MMLS3. Based on the limited laboratory test results, plant-produced WMA mixtures are superior to HMA mixtures in rutting resistance and the moisture susceptibility. The WMA additive was effective for producing and compacting the mixture at $30^{\circ}C$ lower than the temperature for the HMA mixture.

Evaluation of Strength Performance of the Fumigation Treated Wood Affected by the Oak Wilt Disease (참나무시들음병 훈증목의 강도 성능 평가)

  • SONG, Dabin;KIM, Keonho
    • Journal of the Korean Wood Science and Technology
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    • v.48 no.6
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    • pp.820-831
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    • 2020
  • Fumigation treatment is mainly used on dead trees affected by the oak wilt disease to prevent the spread of damage. To verify the possibility of intensive use of the damaged Mongolian Oak wood treated by the fumigation treatment, we performed the compression and bending performance evaluation of the fumigation treated wood. The fumigation was done with Nemasect (Metam-sodium) for about 9 months. The dry longitudinal compressive strength of the fumigation treated oak wilt-diseased wood at the ambient temperature and humidity, and the compressive modulus of elasticity were measured to be 58.87MPa, and 5.66GPa, which were similar to the non-treated wood. The strength performance of mature wood of fumigation treated wood was 16% higher than that of juvenile wood. The compression fracture of the non-treated oak wood showed various shapes, however, most of the fumigation treated wood showed shear-type fracture shape. The bending strength of the fumigate treated wood was measured to be 157.43MPa, which was 8% higher than that of the non-treated wood, and the bending modulus of elasticity was measured to be 16.38GPa, which was 16% lower than that of the non-treated wood. However, it was confirmed that the coefficient of variation for the bending strength performance value of the fumigation treated wood was lower than that of the non-treated wood.

Studies on Alternaria and Corynespora Blights of Sesame (참깨 검은무늬병(病) 및 잎마름병(病)에 관한 연구(硏究))

  • Yu, Seung-Heon;Kim, Hong-Gi;Gang, Yeo-Gyu;Park, Jong-Seong
    • The Korean Journal of Mycology
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    • v.9 no.4
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    • pp.169-176
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    • 1981
  • Survey of sesame crop in the cultivators' field in the district of Daejeon, Yuseong, Sintanjin, Nonsan and Keumsan revealed that Alternaria and Corynespora blights of sesame were wide spread and caused severe damage to sesame plants. Symptoms of a new disease of sesame in Korea caused by Alternaria sesami were spreading, dark-brown to black, water-soaked lesions which often could be traced the entire length of the stem. In severe infections, several lesions coalesced together involving a major portion of the blade and the infected leaves dried and usually dropped off. Symptoms of Corynespora blight, caused by Corynespora cassiicola, were irregular shaped, concentrically-zoned, light brown to reddish brown lesions which later coalesced and caused defoliation. Stem lesions were long, reddish brown streaks that often coalesced, blighting the plants. The optimum temperatures for mycelial growth of A. sesami and C. cassiicola were about $27^{\circ}C$ and sporulations of these 2 fungi were stimulated under alternating light and darkness. Mycelial growth and sporulation of A. sesami and C. cassiicola were the greatest on sesame oatmeal agar (SOA) and potato dextrose agar (PDA), respectively.

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The Anti-bacterial Activity of Eco-friendly Farming Material based on Chinese Nut-gall Extraction on Acidovorax citrulli (오배자 추출물 유래 친환경제제의 세균성과실썩음병균에 대한 항세균활성)

  • Seo, Tae-Jin;Yang, Soo-Jeong;Lee, Bong-Choon;Kim, Kang-Min;Lee, Kui-Jae;Ju, Ho-Jong
    • Korean Journal of Organic Agriculture
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    • v.24 no.3
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    • pp.571-582
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    • 2016
  • Bacterial fruit blotch (BFB) is one of most important diseases in Cucurbitaceae due to infection of Acidovorax citrulli, causing huge economic losses damage worldwide. This seedborn disease spread rapidly at period of high temperature and humidity. The eco-friendly farming is getting popular. So far there was no effective agent to control BFB in eco-friendly farming. Therefore, effect of the material based on chinese nut-gall extract with antibacterial activity against BFB to was tested against A. citrulli. Different hosts showed various symptoms of BFB. Liquid formulation among exhibited most effective anti-bacterial activity on A. citrulli. Pot experiment in greenhouse showed the potential as an control agent of BFB in cucurbits. The treatment of material based on chinese nut-gall extract showed the positive effect on survival of the watermelon seedling and on the length of the cucumber seedling treated with A. citrulli. We cautiously conclude that the material based on chinese nut-gall extract used in this study may be good agents against major diseases of cucurbits in the future even though it is require to be tested with more study on field test.

Disaster Prevention Planning through Analysis of Debris Flow Vulnerability Based on Mountain Basin Features (산지유역 기반의 토석류 취약성 분석을 통한 재해방지 계획수립 연구)

  • Kim, Man-Il;Lee, Moon-Se;Hong, Kwan-Pyo
    • The Journal of Engineering Geology
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    • v.27 no.4
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    • pp.393-403
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    • 2017
  • Mountain disasters in Korea have caused massive social and economic damage. During the period 2005-2014 there has been an annual average of 7 deaths and disaster recovery costs of 79.8 billion won in the country's 4393 ha of mountainous areas. The primary mountain disasters are landslides on mountain slopes, and secondary debris flows can spread along mountain streams, damaging facilities and settlements in lower areas. Typhoons and local rainfall can cause such disasters, while anthropogenic factors include development that damages the mountainous terrain. The study area was divided into three basins. For each basin, a debris flow vulnerability assessment method was proposed considering FLO-2D analysis results and the local topography, geology, and forestation. To establish an in situ investigation, analysis, and evaluation plan for potential mountain disasters, we selected mountain basins that are potentially vulnerable to mountain disasters through analysis of their mountain slopes and streams. This work suggests the establishment of a comprehensive plan for disaster prevention based on a mountain basin feature.

Research Methods on Scalp and Hair Management through the Pass of Time (시대적 흐름에 따른 두피와 모발관리에 대한 연구방법)

  • Kim Myung-Joo;Baek Seung-Hwa
    • Journal of Society of Preventive Korean Medicine
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    • v.7 no.1
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    • pp.123-132
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    • 2003
  • It is considered to be important to create aesthetically beautiful style through the change of external shape, however for the hair stylists, whose beauty expression is through hair, the role of hair doctor is becoming even more important with focus to improve the hair healthiness. Hair clinic is management of hair and scalp. It is the management process of preventing damages, while improving and cultivating healthy and shiny hair. The current concept in hair management is moving from simple hair styling to emphasis at hair management. As far as hair management is concerned, it usually includes treatment tools such as shampoo, conditioner, hair treatment and scalp scaling system, which is used for diagnosis of hair condition in order to treat the scalp. As the interest of hair healthiness becoming more wide spread, so does the breadth of clinic menu. The wide choice is to fulfill the profound desire of people, whose demands are simply to have variety in their choice. This is resulting in faucets of new value-added and differentiated products. The values that make-up the hair styles consist of mainly design (trend, preference), function(styling, management convenience) and clinic(hair quality improvement, damage repair). Shampoo and conditioner have gone beyond their original function of cleansing to providing combinational functions of treatment, to care and remedy, and advanced massage effectiveness. These are, to name a few that seem to go beyond their original function to satisfy the mental healthiness in people, the King Kong shampoo of shampooings in forward-backward manner, 5-minute shampoo massage that applies sports and relaxation massage, scalp acupunctural message and aural(ear) massage. More and more people are complaining about the damaged hair and hair loss problems due to perms, dyeing and bleaching of hair, in addition to natural scalp and hair damaging factors. Such complaints have stimulated many beauty products and various hair treatment systems being introduced with focus to provide nutrition and prevent damages to scalp and hair. As the living standards improve and the desire of people is to pursue differentiated lives, their demand also increases in hair styling products to fulfill the needs of healthy and aesthetical aspects of their lives.

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Development of Emergency Restoration Scenarios for Railway Accident using Analytic Network Process (네트워크분석적 의사결정기법을 이용한 철도사고 임시복구시나리오 개발)

  • Sung, Deok-Yong;Park, Yong-Gul
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.5D
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    • pp.727-737
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    • 2011
  • The emergency restoration scenarios for efficient railway accident management and restoration were developed. The emergency restoration procedures defined by the worst case of emergency restoration and the important events was proposed based on questionnaires from specialists and the result of survey. Via these studies, the railway accident in the tunnel could be the worst case among all railway accident types. Therefore, educations for a restoration team in confined area condition should be planned and performed to recover the worst case accident. In order for the emergency restoration, when a railway accident is occurred, the restoration should be performed in orders of handing collapse of facilities, burying track, and derailment of vehicle in tunnel based on the statistical analysis. The result of priorities were established by the period of restoration. The standard operation system for efficient railway accident management was developed by synthesizing the worst case for rapid emergency restoration, and important events for the standard operation procedures according to each emergency restoration type. Through this study, the restoration operation system of railway accident are recommended. This paper suggests to develop emergency restoration scenarios for the efficient railway accident management and recovery system. The study results will contribute not only for insuring punctuality, but also for minimizing delays from accidents. Therefore, emergency restoration scenarios will play a major role in the SOP for the damage limitation and the prevention of accident spread.

A study on the efficiency advancement for evacuation of the crews by ship structural improvement (선박 구조 개선을 통한 승무원의 피난 효율 향상을 위한 연구)

  • Kim, Wonouk;Lee, Myoungho;Kim, Jongsu
    • Journal of Advanced Marine Engineering and Technology
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    • v.38 no.3
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    • pp.342-348
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    • 2014
  • Onshore great fires can normally be extinguished by firefighters using special firefighting equipment and its suitable method. However, offshore fires on the ships are to be extinguished by the crew without any supports from the onshore. Also, crews working on board are exposed to high risk of emergency evacuation due to the complicated structure arrangement of the ships and different accident types such as fire and ship collisions. As most of damage and loss of life in fire are associated with suffocation, shortening of evacuation time is an important factor to improve a survival rate. In this study, visibility in the accommodation area is analyzed by using the temperature and smoke flow which are obtained by the Fire Dynamic Simulator(FDS) as a Three-Dimensional Fire Analysis program to understand the survival rate of the crew upon the fire. The fire doors for most of ships are designed to close automatically when the fire alarm is activated. These automatic closing of the fire doors is a very effective system to delay the spread of flame and smoke flow for the unmanned spaces of the fire protected area. However, if the crew cannot escape within the estimated time, the crew inside the fire protected area will be damaged a lot. In this paper, the comparative analysis between the evacuations by using the fire door from the fire protected area and the suggested fire shielding structure in this study is carried out by the smoke flow rate and the temperature rise rate.

A Study on the Disaster Prevention of the Royal Tomb Eureung in the Mountain Cheonjang - Estimation on Forest Fire Risk Considering Forest Type and Topography - (천장산 의릉의 방재대책에 관한 연구 - 임상과 지형인자를 고려한 산불위험성 평가 -)

  • Won, Myoung-Soo;Lee, Woo-Kyun;Choi, Jong-Hee
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.28 no.1
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    • pp.59-65
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    • 2010
  • The purpose of this study is to analyze the risk of the forest fire, considering the topography and the forest, for establishing disaster prevention measures of cultural heritage, Uireung, over in Cheonjang-mountain. To do that, we estimate the occurrence and spread of the forest fire over in Cheonjang-mountain through a forest fire probability model(logistic regression), using the space characteristic data($100m{\times}100m$). The factor, occurrence of the forest fire, are diameter class, southeast, southwest, south, coniferous, deciduous, and mixed forest. We assume the probability of the fire forest in each point as follow : [1+exp{-(-4.8081-(0.02453*diameter class)+(0.6608*southeast)+(0.507*southwest)+(0.7943*south)+(0.29498*coniferous forest)+(0.28897*deciduous forest)+(0.17788*mixed forest))}]$^{-1}$. To divide dangerous zone of the big forest fire, we make the basic materials for disaster prevention measures, through the map of coniferous forests, deciduous forests, and mixed forest. The damage of cultural heritage caused by a forest fire will be reduced through the effective preventive measures, by forecast a forest fire to using this study.

Dangerous Area Prediction Technique for Preventing Disaster based on Outside Sensor Network (실외 센서네트워크 기반 재해방지 시스템을 위한 위험지역 예측기법)

  • Jung, Young-Jin;Kim, Hak-Cheol;Ryu, Keun-Ho
    • The KIPS Transactions:PartD
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    • v.13D no.6 s.109
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    • pp.775-788
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    • 2006
  • Many disaster monitoring systems are constantly studied to prevent disasters such as environmental pollution, the breaking of a tunnel and a building, flooding, storm earthquake according to the progress of wireless telecommunication, the miniaturization of terminal devices, and the spread of sensor network. A disaster monitoring system can extract information of a remote place, process sensor data with rules to recognize disaster situation, and provide work for preventing disaster. However existing monitoring systems are not enough to predict and prevent disaster, because they can only process current sensor data through utilizing simple aggregation function and operators. In this paper, we design and implement a disaster prevention system to predict near future dangerous area through using outside sensor network and spatial Information. The provided prediction technique considers the change of spatial information over time with current sensor data, and indicates the place that could be dangerous in near future. The system can recognize which place would be dangerous and prepare the disaster prevention. Therefore, damage of disaster and cost of recovery would be reduced. The provided disaster prevention system and prediction technique could be applied to various disaster prevention systems and be utilized for preventing disaster and reducing damages.