• Title/Summary/Keyword: Thermal Anomalies

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Analyzing the Evolution of Summer Thermal Anomalies in Busan Using Remote Sensing and Spatial Statistical Tool

  • Njungwi, Nkwain Wilfred;Lee, Daeun;Kim, Minji;Jin, Cheonggil;Choi, Chuluong
    • Korean Journal of Remote Sensing
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    • v.37 no.4
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    • pp.665-685
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    • 2021
  • This study focused on the a 20-year evaluation of the dynamism of critical thermal anomalies in Busan metropolitan area prompted by unusual infrastructural development and demographic growth rate. Archived Landsat thermal data derived-LST was the major input for UTFVI and hot spot analysis (Getis-Ord Gi*). Results revealed that the surface urban heat island-affected area has gradually expanded overtime from 23.32% to 32.36%; while the critical positive thermal anomalies (level-3 hotspots) have also spatially increased from 19.88% in 2000 to 23.56% in 2020, recording a net LST difference of > 5℃ between the maximum level-3 hotspot and minimum level-3 coldspot each year. It is been observed that thermal conditions of Busan have gradually deteriorated with time, which is potentially inherent in the rate of urban expansion. Thus, this work serves as an eye-opener to powers that be, to think and act constructively towards a sustainable thermal conform for city dwellers.

Is Liquid Water a Hot Quantum Fluid? Anomalies of Water in Thin Liquid Films and in Biological Systems

  • Yoon, Byoung-Jip
    • Bulletin of the Korean Chemical Society
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    • v.24 no.8
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    • pp.1211-1214
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    • 2003
  • The anomalies that appear at every multiple of 15 ℃ in the viscosity of a thin liquid film of water and of water near solid interfaces are explained in this paper by comparing the thermal wavelength and molecular free volume of water, and quantum numbers are found. The possibility that these anomalies are related to the preferred and/or lethal temperatures of organisms is considered. The toxicity of heavy water (D₂O) can also be explained with this approach.

Interpretation of Gravity, Magnetic and High-resolution (3.5 kHz) Seismic Data in the Powell Basin, Antarctica (남극 파월분지 지역의 중,자력 및 고해상 (3.5 KHZ) 탄성파 자료 해석)

  • Jin, YoungKeun;Kim, KyuJung;Nam, SangHeon;Kim, YeaDong;Lee, JooHan
    • Journal of the Korean Geophysical Society
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    • v.7 no.1
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    • pp.1-10
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    • 2004
  • Gravity, magnetic and high-resolution seismic surveys were carried out in the Powell Basin to examine tectonic structure and recent sedimentation on Dec. 2002. The trend of negative gravity anomalies along the spreading axis of the Powell Basin changes from northwest to east-west toward south. Both boundaries of the basin with the Antarctic Peninsula and the South Orkey micro-continent show negative magnetic anomalies, which indicates that the boundaries were continental rift areas in the initial stage of spreading. Magnitude of the magnetic anomalies corresponding to the axis of the basin is rather small compared to those of normal spreading axises in other regions. Such small anomalies would be caused by reduction of magnetic strength of oceanic crust below thick sediments due to thermal alternation. High-resolution (3.5 kHz) seismic profiles reveal that top of the South Scotia Ridge is a flat terrain coverd with thin coarse sediments by glacial erosion. Thick oceanic sediments are deposited in the central part of the basin. Little deformation in the oceanic sediments indicates that the Powell Basin has been in stable tectonic environment after spreading of the basin stopped.

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Prediction of SST for Operational Ocean Prediction System

  • Kang, Yong-Quin
    • Ocean and Polar Research
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    • v.23 no.2
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    • pp.189-194
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    • 2001
  • A practical algorithm for prediction of the sea surface temperatures (SST)from the satellite remote sensing data is presented in this paper. The fluctuations of SST consist of deterministic normals and stochastic anomalies. Due to large thermal inertia of sea water, the SST anomalies can be modelled by autoregressive or Markov process, and its near future values can be predicted provided the recent values of SST are available. The actual SST is predicted by superposing the pre-known SST normals and the predicted SST anomalies. We applied this prediction algorithm to the NOAA AVHRR weekly SST data for 18 years (1981-1998) in the seas adjacent to Korea (115-$145^{\circ}E$, 20-$55^{\circ}N$). The algorithm is applicable not only for prediction of SST in near future but also for nowcast of SST in the cloud covered regions.

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A Study on the Heat Generation and Thermal Conductivity of Crustal Rocks (지각 구성 암석의 열생산량과 열전도도에 관한 연구)

  • Han, Uk
    • Economic and Environmental Geology
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    • v.26 no.3
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    • pp.371-382
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    • 1993
  • Compilations of thermal conductivity and radiogenic heat production on 20 typical rock types provide a convenient summary. These compilations allow estimates to be made of the radioactive heat generation for the continental crust and thus heat flow anomalies of tectonic origin to be isolated.

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Characteristics Analysis of Measurement Variables for Detecting Anomaly Signs of Thermal Runaway in Lithium-Ion Batteries (리튬이온 배터리의 열폭주 이상징후 감지를 위한 측정 변수 특성 분석)

  • LIM, BYUNG-JU;CHO, SUNG-HOON;LEE, GA-RAM;CHOI, SEOK-MIN;PARK, CHANG-DAE
    • Transactions of the Korean hydrogen and new energy society
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    • v.33 no.1
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    • pp.85-94
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    • 2022
  • To detect anomaly signs of thermal runaway in advance, this study analyzed the signals from various sensors installed in lithium-ion batteries. The thermal runaway mechanism was analyzed, and measurement variables for anomalies of a battery cell were surface temperature, strain, and gas concentration. The changes and characteristics of three variables during the thermal runaway process were analyzed under the abuse environment: the overheat and the overcharge. In experiment, the thermal runaway of the battery proceeded in the initial developing stage, the outgassing stage, and the ignition stage. Analysis from the measured data indicated that the suitable variable to detect all stages of thermal runaway is the surface temperature of the battery, and surface strain is alternative.

Power Absorption Measurements during NMR Experiments

  • Felix-Gonzalez, N.;Urbano-Bojorge, A.L.;de Pablo, C. Sanchez-L;Ferro-Llanos, V.;del Pozo-Guerrero, F.;Serrano-Olmedo, J.J.
    • Journal of Magnetics
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    • v.19 no.2
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    • pp.155-160
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    • 2014
  • The heating produced by the absorption of radiofrequency (RF) has been considered a secondary undesirable effect during MRI procedures. In this work, we have measured the power absorbed by distilled water, glycerol and egg-albumin during NMR and non-NMR experiments. The samples are dielectric and examples of different biological materials. The samples were irradiated using the same RF pulse sequence, whilst the magnetic field strength was the variable to be changed in the experiments. The measurements show a smooth increase of the thermal power as the magnetic field grows due to the magnetoresistive effect in the copper antenna, a coil around the probe, which is directly heating the sample. However, in the cases when the magnetic field was the adequate for the NMR to take place, some anomalies in the expected thermal powers were observed: the thermal power was higher in the cases of water and glycerol, and lower in the case of albumin. An ANOVA test demonstrated that the observed differences between the measured power and the expected power are significant.

Interaction among the East Asian Summer and Winter Monsoons, the Tropical Western Pacific and ENSO Cycle

  • Huang, Rong-Hui;Lu, Ri-Yu;Chen, Wen;Chen, Ji-Rong
    • Atmosphere
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    • v.13 no.2
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    • pp.47-68
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    • 2003
  • Recent advances in the studies on the interaction between Asian monsoon and ENSO cycle are reviewed in this paper. Through the recent studies, the East Asian summer monsoon circulation system and the East Asian climate system have proposed. Moreover, different responses of the (winter and summer) monsoon circulation and summer rainfall anomalies in East Asia to ENSO cycle during its different stages have been understood further. Recently, the studies on the dynamical effect of East Asian monsoon on the thermal variability of the tropical western Pacific and ENSO cycle have been greatly advanced. These studies demonstrated further that ENSO cycle originates from the tropical western Pacific, and pointed out that the dynamical effect of East Asian winter and summer monsoons on ENSO cycle may be through the atmospheric circulation and zonal wind anomalies over the tropical western Pacific, which can excite the oceanic Kelvin wave and Rossby waves in the equatorial Pacific. Besides, the scientific problems in the interaction between Asian monsoon and ENSO cycle, which should be studied further in the near future, are also pointed out in this paper.

The Influence of Global Sea Surface Temperature Anomalies on Droughts in the East Asia Monsoon Region

  • Awan, Jehangir Ashraf;Bae, Deg-Hyo
    • Proceedings of the Korea Water Resources Association Conference
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    • 2015.05a
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    • pp.224-224
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    • 2015
  • The East Asia monsoon is one of the most complex atmospheric phenomena caused by Land-Sea thermal contrast. It plays essential role in fulfilling the water needs of the region but also poses stern consequences in terms of flooding and droughts. This study analyzed the influence of Global Sea Surface Temperature Anomalies (SSTA) on occurrence of droughts in the East Asia monsoon region ($20^{\circ}N-50^{\circ}N$, $103^{\circ}E-149^{\circ}E$). Standardized Precipitation Index (SPI) was employed to characterize the droughts over the region using 30-year (1978-2007) gridded rainfall dataset at $0.5^{\circ}$ grid resolution. Due to high variability in intensity and spatial extent of monsoon rainfall the East Asia monsoon region was divided into the homogeneous rainfall zones using cluster analysis method. Seven zones were delineated that showed unique rainfall regimes over the region. The influence of SSTA was assessed by using lagged-correlation between global gridded SSTA ($0.2^{\circ}$ grid resolution) and SPI of each zone. Sea regions with potential influence on droughts in different zones were identified based on significant positive and negative correlation between SSTA and SPI with a lag period of 3-month. The results showed that SSTA have the potential to be used as predictor variables for prediction of droughts with a reasonable lead time. The findings of this study will assist to improve the drought prediction over the region.

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An Analytical Approach to the Flight Safety of Split Yaw Swaged Rod for a Rotor Craft (회전익기 요 스웨지드 로드 분할에 따른 비행 안전성에 대한 해석적 접근)

  • Lim, Hyun-Gyu;Choi, Jae-hyung;Kim, Dae-Han;Jang, Min-Wook;Yoon, Jae-Huy;Yang, Pil-Joo
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.25 no.3
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    • pp.74-80
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    • 2017
  • As for A rotary wing aircraft, the configuration change about split yaw swaged rod was executed to improve hit treat capability for dealing with a long rod. The purpose of this study was to analyze if or not the quality of the split yaw swaged rod was obtained, and so the flight safety was ensured or not. Buckling analysis, Coupling Thread Strength Analysis, Thermal Stress analysis and Rod Natural Frequency Analysis were executed for structural analysis. The results of the analysis were presented that the split rod had the sufficient margin of safety and so there were no anomalies in the limit load and no failures in the ultimate load. And there were no resonances in result of natural frequency analysis. In conclusion, this study showed that the split yaw swaged rod had structural safety, so flight safety of rotary wing aircraft was secured and there was no problem in aircraft operation. It is certain that the technology of splitting the yaw swage rod will contribute to the operational Safety of the rotary wing aircraft in the future.