• 제목/요약/키워드: extreme temperatures

검색결과 162건 처리시간 0.032초

환경 스트레스 조건에 따른 화경버섯 균사의 생물발광 변화 (Changes in Bioluminescence of Omphalotus japonicus Mycelia under Environmental Stress Conditions)

  • 박미정;이효림;유림
    • 한국균학회지
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    • 제48권4호
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    • pp.381-388
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    • 2020
  • 생물발광은 생물체 내에서 빛이 방출되는 현상을 말한다. 이 현상은 루시페라아제(luciferase)에 촉매되는 루시페린(luciferin)의 산화 반응에 의해 나타난다. 생물발광은 균류를 포함하여 다양한 생물 종에서 나타남이 알려져 있다. 현재까지 약 80여 종의 균류에서 생물발광이 관찰됨이 보고 되었다. 화경버섯(Omphalotus japonicus)은 한국에 자생하는 대표적인 생물발광버섯이다. 본 연구에서는 화경버섯 균사의 생물발광에 대하여 조사하였다. 그 결과, 고체 배지에서 자란 화경버섯 균사체의 가장자리 부근에서 중심부에 비해 높은 발광이 관찰되었다. 또한 균사 표면에 상처를 내자 해당 부위에서 강한 생물발광이 관찰되었다. 이러한 생물발광의 증가는 처리 후 3시간에 최대로 나타났다. 다음으로 극단적인 온도 스트레스에 의한 생물 발광의 변화에 대해서도 살펴보았다. 그 결과, 외부 자극에 의한 상처 스트레스와 달리 고온이나 저온 스트레스에 의해 균사의 생물 발광이 억제됨을 확인하였다. 환경 스트레스에 의해 일어나는 생물발광 변화의 생리학적 및 생태학적 의미를 밝히기 위해 더 많은 연구가 필요할 것이다.

아두이노를 활용한 식물재배 시스템에 대한 연구 (Plant Cultivation System using Arduino)

  • 김민주;박진우;장동환;김시현;윤호식;이성진;문상호
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2021년도 춘계학술대회
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    • pp.386-388
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    • 2021
  • 2019년도의 세계기상기구(WMO)의 자료에 따르면, 2015~2019년의 전 지구 평균기온은 산업화 이전 시기(1850~1900년)보다 1.1℃ 상승하였다. 평균기온이 1.5℃가 상승할 경우 극한 고온, 호우 및 가뭄 등 자연재해의 발생이 증가할 것이며 이러한 변화가 온난화 속도와 규모에 따라 더욱 심화할 것으로 전망하였다. 이러한 지구온난화의 영향으로 인해 지구 지표면 기온이 점차 상승하게 되면서 열대지방에서나 재배할 수 있었던 과일을 우리나라에서도 열대과일이 재배되어 수확하는 현상을 볼 수 있게 되었다. 유엔 산하 기후변화에 관한 정부 간 협의체 IPCC가 발표한 5차 보고서에 따르면 지금 추세대로라면 21세기 말(2081~2100년) 세계 평균기온 현재보다 3.7도가 상승할 것으로 전망했다. 점진적으로 기온이 상승하면 우리나라의 현재 좋은 품질의 과일을 생산할 수 있는 재배지역이 미래에는 불리한 지역으로 바뀔 수 있다는 위기에 직면하게 되었다고 판단된다. 본 논문에서는 아두이노를 활용하여 재배자가 원하는 식물의 성장을 위해 맞춤 환경을 제공하는 식물재배 시스템을 개발한다.

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합성형교량의 설계온도하중 (Design Thermal Loads In Composite Box Girder Bridges)

  • 장승필;임창균
    • 한국강구조학회 논문집
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    • 제10권3호통권36호
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    • pp.537-551
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    • 1998
  • 본 논문에서는 장기온도측정자료의 통계해석에 바탕을 두고, 합성박스형교량에 작용하는 설계온도하중의 적절한 값을 제안하고자 한다. 이를 위해, 최근에 건설된 합성박스형교량에서 약 20개월간 온도측정을 수행하였다. 극치해석에 앞서, 온도분포특성을 나타내는 주요 매개변수를 정의하고, 이의 계절별변화에 대해 상세히 검토하였다. 이 온도하중매개변수의 극치분포를 Tail-Equivalence법에 의해 결정하고, 주어진 재현기간에 해당되는 온도하중매개변수의 극치값을 계산하였다. 끝으로, 이 결과들을 현 시방서에서 온도하중에 대해 제안하고있는 규정들과 비교하였다. 비교결과로부터, 현 시방서는 합성박스형교량의 온도응력을 나타내는데 불충분하며, 특별한 경우에 있어서 현 설계규정에 포함되지않은 수평방향온도변화를 고려해야만 된다는 결론에 도달하였다.

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다양한 주행모드 및 시험 조건에 따른 전기자동차 효율 특성 (The Efficiency Characteristics of Electric Vehicle (EV) According to the Diverse Driving Modes and Test Conditions)

  • 이민호;김성우;김기호
    • 한국수소및신에너지학회논문집
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    • 제28권1호
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    • pp.56-62
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    • 2017
  • Although most electricity production contributes to air pollution, the vehicle organizations and environmental agency categorizes all EVs as zero-emission vehicles because they produce no direct exhaust or emissions. Currently available EVs have a shorter range per charge than most conventional vehicles have per tank of gas. EVs manufacturers typically target a range of 160 km over on a fully charged battery. The energy efficiency and driving range of EVs varies substantially based on driving conditions and driving habits. Extreme outside temperatures tend to reduce range, because more energy must be used to heat or cool the cabin. High driving speeds reduce range because of the energy required to overcome increased drag. Compared with gradual acceleration, rapid acceleration reduces range. Additional devices significant inclines also reduces range. Based on these driving modes and climate conditions, this paper discusses the performance characteristics of EVs on energy efficiency and driving range. Test vehicles were divided by low / high-speed EVs. The difference of test vehicles are on the vehicle speed and size. Low-speed EVs is a denomination for battery EVs that are legally limited to roads with posted speed limits as high as 72 km/h depending on the particular laws, usually are built to have a top speed of 60 km/h, and have a maximum loaded weight of 1,400 kg. Each vehicle test was performed according to the driving modes and test temperature ($-25^{\circ}C{\sim}35^{\circ}C$). It has a great influence on fuel efficiency amd driving distance according to test temperature conditions.

Early age behavior analysis for reinforced concrete bridge pier

  • Wang, Xianfeng;Li, Dawang;Han, Ningxu;Xing, Feng
    • Computers and Concrete
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    • 제18권5호
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    • pp.1041-1051
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    • 2016
  • In this study, the construction of a reinforced concrete bridge pier was analyzed from durability point of view. The goal of the study is to analyze the crack iniation condition due to construction and present some recommendations for construction conditions of the reinforced concrete bridge pier. The bridge is located at the western port area of Shenzhen, where the climate is high temperature and humidity. To control the cracking of concrete, a construction simulation was carried out for a heat transfer problem as well as a thermal stress problem. A shrinkage model for heat produced due to cement hydration and a Burger constitutive model to simulate the creep effect are used. The modelling based on Femmasse(C) is verified by comparing with the testing results of a real underground abutment. For the bridge pier, the temperature and stress distribution, as well as their evolution with time are shown. To simulate the construction condition, four initial concrete temperatures ($5^{\circ}C$, $10^{\circ}C$, $15^{\circ}C$, $20^{\circ}C$) and three demoulding time tips (48h, 72h, 96h) are investigated. From the results, it is concluded that a high initial concrete temperature could result in a high extreme internal temperature, which causes the early peak temperature and the larger principle stresses. The demoulding time seems to be less important for the chosen study cases. Currently used 72 hours in the construction practice may be a reasonable choice.

Spatial Physicochemical and Metagenomic Analysis of Desert Environment

  • Sivakala, Kunjukrishnan Kamalakshi;Jose, Polpass Arul;Anandham, Rangasamy;Thinesh, Thangathurai;Jebakumar, Solomon Robinson David;Samaddar, Sandipan;Chatterjee, Poulami;Sivakumar, Natesan;Sa, Tongmin
    • Journal of Microbiology and Biotechnology
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    • 제28권9호
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    • pp.1517-1526
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    • 2018
  • Investigating bacterial diversity and its metabolic capabilities is crucial for interpreting the ecological patterns in a desert environment and assessing the presence of exploitable microbial resources. In this study, we evaluated the spatial heterogeneity of physicochemical parameters, soil bacterial diversity and metabolic adaptation at meter scale. Soil samples were collected from two quadrats of a desert (Thar Desert, India) with a hot, arid climate, very little rainfall and extreme temperatures. Analysis of physico-chemical parameters and subsequent variance analysis (p-values < 0.05) revealed that sulfate, potassium and magnesium ions were the most variable between the quadrats. Microbial diversity of the two quadrats was studied using Illumina bar-coded sequencing by targeting V3-V4 regions of 16S rDNA. As for the results, 702504 high-quality sequence reads, assigned to 173 operational taxonomic units (OTUs) at species level, were examined. The most abundant phyla in both quadrats were Actinobacteria (38.72%), Proteobacteria (32.94%), and Acidobacteria (9.24%). At genus level, Gaiella represented highest prevalence, followed by Streptomyces, Solirubrobacter, Aciditerrimonas, Geminicoccus, Geodermatophilus, Microvirga, and Rubrobacter. Between the quadrats, significant difference (p-values < 0.05) was found in the abundance of Aciditerrimonas, Geodermatophilus, Geminicoccus, Ilumatobacter, Marmoricola, Nakamurella, and Solirubrobacter. Metabolic functional mapping revealed diverse biological activities, and was significantly correlated with physicochemical parameters. The results revealed spatial variation of ions, microbial abundance and functional attributes in the studied quadrats, and patchy nature in local scale. Interestingly, abundance of the biotechnologically important phylum Actinobacteria, with large proposition of unclassified species in the desert, suggested that this arid environment is a promising site for bioprospection.

Potential Influence of Climate Change on Shellfish Aquaculture System in the Temperate Region

  • Jo, Qtae;Hur, Young Baek;Cho, Kee Chae;Jeon, Chang Young;Lee, Deok Chan
    • 한국패류학회지
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    • 제28권3호
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    • pp.277-291
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    • 2012
  • Aquaculture is challenged by a number of constraints with future efforts towards sustainable production. Global climate change has a potential damage to the sustainability by changing environmental surroundings unfavorably. The damaging parameters identified are water temperature, sea level, surface physical energy, precipitation, solar radiation, ocean acidification, and so on. Of them, temperature, mostly temperature elevation, occupies significant concern among marine ecologists and aquaculturists. Ocean acidification particularly draws shellfish aquaculturists' attention as it alters the marine chemistry, shifting the equilibrium towards more dissolved CO2 and hydrogen ions ($H^+$) and thus influencing signaling pathways on shell formation, immune system, and other biological processes. Temperature elevation by climate change is of double-sidedness: it can be an opportunistic parameter besides being a generally known damaging parameter in aquaculture. It can provide better environments for faster and longer growth for aquaculture species. It is also somehow advantageous for alleviation of aquaculture expansion pressure in a given location by opening a gate for new species and aquaculture zone expansion northward in the northern hemisphere, otherwise unavailable due to temperature limit. But in the science of climate change, the ways of influence on aquaculture are complex and ambiguous, and hence are still hard to identify and quantify. At the same time considerable parts of our knowledge on climate change effects on aquaculture are from the estimates from data of fisheries and agriculture. The consequences may be different from what they really are, particularly in the temperature region. In reality, bivalves and tunicates hung or caged in the longline system are often exposed to temperatures higher than those they encounter in nature, locally driving the farmed shellfish into an upper tolerable temperature extreme. We review recent climate change and following environment changes which can be factors or potential factors affecting shellfish aquaculture production in the temperate region.

Importance and production of chilli pepper; heat tolerance and efficient nutrient use under climate change conditions

  • Khaitov, Botir;Umurzokov, Mirjalol;Cho, Kwang-Min;Lee, Ye-Jin;Park, Kee Woong;Sung, JwaKyung
    • 농업과학연구
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    • 제46권4호
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    • pp.769-779
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    • 2019
  • Chilli peppers are predominantly cultivated in open field systems under abiotic and biotic stress conditions. Abiotic and biotic factors have a considerable effect on plant performance, fruit quantity, and quality. Chilli peppers grow well in a tropical climate due to their adaptation to warm and humid regions with temperatures ranging from 18 to 30℃. Nowadays, chilli peppers are cultivated all around the world under different climatic conditions, and their production is gradually expanding. Expected climate changes will likely cause huge and complex ecological consequences; high temperature, heavy rainfall, and drought have adverse effects on the vegetative and generative development of all agricultural crops including chilli peppers. To gain better insight into the effect of climate change, the growth, photosynthetic traits, morphological and physiological characteristics, yield, and fruit parameters of chilli peppers need to be studied under simulated climate change conditions. Moreover, it is important to develop alternative agrotechnologies to maintain the sustainability of pepper production. There are many conceivable ideas and concepts to sustain crop production under the extreme conditions of future climate change scenarios. Therefore, this review provides an overview of the adverse impacts of climate change and discusses how to find the best solutions to obtain a stable chilli pepper yield.

영동지역 대설 사례의 대기 하층 안정도 분석 (An Analysis of Low-level Stability in the Heavy Snowfall Event Observed in the Yeongdong Region)

  • 이진화;은승희;김병곤;한상옥
    • 대기
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    • 제22권2호
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    • pp.209-219
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    • 2012
  • Extreme heavy snowfall episodes have been investigated in case of accumulated snowfall amount larger than 50 cm during the past ten years, in order to understand the association of low-level stability with heavy snowfall in the Yeongdong region. In general, the selected 4 events have similar synoptic setting such as the Siberian High extended to East Sea along with the Low passing by the southern Korean Peninsula, eventually inducing easterly in the Yeongdong region. Specifically moist-adiabatically neutral layer has been observed during the heavy snowfall period, which was easily identified using vertical profiles of equivalent potential temperature observed at Sokcho, whereas convective unstable layer has been formed over the East sea due to relatively warm sea surface temperature (SST) about $8{\sim}10^{\circ}C$ and lower temperature around 1~2 km above the surface, obtained from RDAPS. Difference of equivalent potential temperature between 850 hPa and surface as well as difference between air and sea temperatures altogether gradually increased before the snowfall period. Instability-induced moisture supply to the atmosphere from the East sea, being cooled and saturated by the upper cold surge, would make low-level ice cloud, and eventually move inland by the easterly flow. Heavy snowfall will be enhanced in association with low-level convergence by surface friction and upslope wind against Taebaek mountains. This study emphasizes the importance of low level stability in the Yeongdong region using the radiosonde sounding and RDAPS data, which should quantitatively be examined through numerical model as well as heat and moisture supply from the ocean.

Variability of Stem-Base Infestation and Coexistence of Fusarium spp. Causing Crown Rot of Winter Wheat in Serbia

  • Jevtic, Radivoje;Stosic, Nemanja;Zupunski, Vesna;Lalosevic, Mirjana;Orbovic, Branka
    • The Plant Pathology Journal
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    • 제35권6호
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    • pp.553-563
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    • 2019
  • Investigations related with factors influencing root and crown rot are rare and mainly related to farming practice and soil management. The main objective of this study was to examine broader range of factors influencing stem-base infestation of winter wheat in the field conditions. The effect of spatial distribution of infected plants on disease index (DIs) assessments was also investigated. Analysis of factors influencing DIs of crown rot of wheat demonstrated significant influence of the growing seasons (P < 0.001) and extreme fluctuations in winter temperatures (P < 0.001). In addition to that, localities together with their interaction with the growing season also significantly influenced DIs (P < 0.001). Aggregation of infected plants influenced variability of DI estimations, and it was pointed out that more extensive investigation should be conducted on broad range of DI in order to establish sampling method giving uniform sampling precision. Fusarium graminearum was shown to be predominant Fusarium species in Serbia (72.6%) using sequence-characterized amplified region analysis. Interestingly F. oxysporum was isolated in higher frequencies (27.4%) than it was reported in the literature. Given that there were no reports on the diversity of Fusarium species causing crown rot of wheat in Serbia, this study presents first report on this important subject. It also indicated that more attention should be focused on combined effects of abiotic and biotic factors influencing stem-base infestation of winter wheat. This knowledge will contribute to better understanding of factors influencing root and crown rot of wheat which would ensure sustainable disease management in the future.