• Title/Summary/Keyword: Temperature Sensitivity

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SIMULATION OF SOIL MOISTURE VARIABILITY DUE TO CLIMATE ORANGE IN NORTHEAST POND RIVER WATERSHED, NEWFOUNDLAND, CANADA

  • A. Ghosh Bobba;Vijay P. Singh
    • Water Engineering Research
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    • v.4 no.1
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    • pp.31-43
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    • 2003
  • The impacts of climate change on soil moisture in sub - Arctic watershed simulated by using the hydrologic model. A range of arbitrary changes in temperature and precipitation are applied to the runoff model to study the sensitivity of soil moisture due to potential changes in precipitation and temperature. The sensitivity analysis indicates that changes in precipitation are always amplified in soil moisture with the amplification factor for flow. The change in precipitation has effect on the soil moisture in the catchment. The percentage change in soil moisture levels can be greater than the percentage change in precipitation. Compared to precipitation, temperature increases or decreases alone have impacts on the soil moisture. These results show the potential for climate change to bring about soil moisture that may require a significant planning response. They are also indicative of the fact that hydrological impacts affecting water supply may be important in consider-ing the cost and benefits of potential climate change.

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High Temperature Silicon Pressure Sensor of SDB Structure (SDB 구조의 고온용 실리콘 압력센서)

  • Park, Jae-Sung;Choi, Deuk-Sung;Kim, Mi-Mok
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.6
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    • pp.305-310
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    • 2013
  • In this paper, the pressure sensor usable in a high temperature, using a SDB(silicon-direct-bonding) wafer of Si/$SiO_2$/Si-sub structure was provided and studied the characteristic thereof. The pressure sensor produces a piezoresistor by using a single crystal silicon as a first layer of SDB wafer, to thus provide a prominent sensitivity, and dielectrically isolates the piezoresistor from a silicon substrate by using a silicon dioxide layer as a second layer thereof, to be thus usable even under the high temperature over $120^{\circ}C$ as a limited temperature of a general silicon sensor. The measured result for a pressure sensitivity of the pressure sensor has a characteristic of high sensitivity, and its tested result for an output of the sensor further has a very prominent linearity and hysteresis characteristic.

Impact of Urban Canopy and High Horizontal Resolution on Summer Convective Rainfall in Urban Area: A case Study of Rainfall Events on 16 August 2015 (도시 캐노피와 수평 고해상도가 여름철 대류성 도시 강수에 미치는 영향: 2015년 8월 16일 서울 강수 사례 분석)

  • Lee, Young-Hee;Min, Ki-Hong
    • Atmosphere
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    • v.26 no.1
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    • pp.141-158
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    • 2016
  • The objective of this study is to examine the impact of urban canopy and the horizontal resolution on simulated meteorological variables such as 10-m wind speed, 2-m temperature and precipitation using WRF model for a local, convective rainfall case. We performed four sensitivity tests by varying the use of urban canopy model (UCM) and the horizontal resolution, then compared the model results with observations of AWS network. The focus of our study is over the Seoul metropolitan area for a convective rainfall that occurred on 16 August 16 2015. The analysis shows that mean diurnal variation of temperature is better simulated by the model runs with UCM before the convective rainfall. However, after rainfall, model shows significant difference in air temperature among sensitivity tests depending on the simulated rainfall amount. The rainfall amount is significantly underestimated in 0.5 km resolution model run compared to 1.5 km resolution, particularly over the urban areas. This is due to earlier occurrence of light rainfall in 0.5 km resolution model. Earlier light rainfall in the afternoon eliminates convective instability significantly, which prevents occurrence of rainfall later in the evening. The use of UCM results in a higher maximum rainfall in the domain, which is due to higher temperature in model runs with urban canopy. Earlier occurrence of rainfall in 0.5 km resolution model is related to rapid growth of PBL. Enhanced mixing and higher temperature result in rapid growth of PBL, which provides more favorable conditions for convection in the 0.5 km resolution run with urban canopy. All sensitivity tests show dry bias, which also contributes to the occurrence of light precipitation throughout the simulation period.

A Study on Joule Heating Simulation Method to Prevent Sensitivity Current Trip of Electric Vehicle Charger (전기자동차 충전기의 누전차단기 감도 전류 Trip 방지를 위한 Joule Heating 시뮬레이션 방안연구)

  • Lee, Beoung-Kug;Eo, Ik-soo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.4
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    • pp.150-159
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    • 2021
  • This study aimed to prevent inconvenience to electric vehicle users caused by an interruption of charging by the earth leakage breaker trip that occurs during charging. As a field case study, it was confirmed that during the battery charger failure type, leakage current measurement experiment by vehicle type, and leakage current breaker operation experiment, the internal temperature of the charger rose to more than 60 ℃ in summer, and the earth leakage circuit breaker stopped charging by tripping at 80% of the rated sensitivity current. Through Joule heating modeling, 32A is energized at the reference temperature of 30 ℃ at the initial time t=0 (s). After t=3000 (s), the heat generated around the charging part of the earth leakage breaker increased to 32.4 ℃. The temperature and time factors correlated with the amount of heat generated according to the statistical verification tool with a correlation coefficient of 0.97. Overall, it is possible to prevent the leakage breaker sensitivity current trip due to an increase in temperature inside the charger in summer by performing a Joule heating simulation according to the material of the charging case, the arrangement of the internal wiring, and the dielectric medium when developing the charger device.

Preliminary Analysis on IASCC Sensitivity of Core Shroud in Reactor Pressure Vessel (원자로 노심 쉬라우드의 조사유기응력부식균열 민감도 예비 분석)

  • Kim, Jong-Sung;Park, Chang Je
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.15 no.2
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    • pp.58-63
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    • 2019
  • This paper presents preliminary analysis and results on IASCC sensitivity of a core shroud in the reactor pressure vessel. First, neutron irradiation flux distribution of the reactor internals was calculated by using the Monte Carlo simulation code, MCNP6.1 and the nuclear data library, ENDF/B-VII.1. Second, based on the neutron irradiation flux distribution, temperature and stress distributions of the core shroud during normal operation were determined by performing finite element analysis using the commercial finite element analysis program, ABAQUS, considering irradiation aging-related degradation mechanisms. Last, IASCC sensitivity of the core shroud was assessed by using the IASCC sensitivity definition of EPRI MRP-211 and the finite element analysis results. As a result of the preliminary analysis, it was found that the point at which the maximum IASCC sensitivity is derived varies over operating time, initially moving from the shroud plate located in the center of the core to the top shroud plate-ring connection brace over operating time. In addition, it was concluded that IASCC will not occur on the core shroud even after 60 years of operation (40EFPYs) because the maximum IASCC sensitivity is less than 0.5.

Gas sensing characteristics of $TiO_{2}/WO_{3}$ thick film for hydrocarbon gas (후막형 $TiO_{2}/WO_{3}$ 소자의 탄화수소계가스에 대한 감도 특성)

  • Chang, Dong-Hyuck;Choi, Dong-Han
    • Journal of Sensor Science and Technology
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    • v.5 no.2
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    • pp.21-27
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    • 1996
  • Thick film $TiO_{2}/WO_{3}$ butane gas sensors were fabricated by the screen printing method and their gas sensing characteristics were investigated. The sensitivity of $TiO_{2}/WO_{3}$ thick film was higher than that of pure $WO_{3}$ film to butane. The $WO_{3}$ film with 2wt.% $TiO_{2}$ showed the highest sensitivity to butane. And the optimum heat treatment temperature was $650^{\circ}C$. That film showed the highest sensitivity to butane at the operating temperature of $350^{\circ}C$. The sensitivity of the film to 20000ppm butane in air was 80% at the operating temperature of $350^{\circ}C$.

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Fiber Interferometers Based on Low Loss Fusion Splicing of Photonic Crystal Fibers (저손실 융착접속을 이용한 광자결정 광섬유 간섭계)

  • Ahn, Jin-Soo;Kim, Gil-Hwan;Lee, Kwan-Il;Lee, Kyung-Shik;Lee, Sang-Bae
    • Korean Journal of Optics and Photonics
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    • v.21 no.5
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    • pp.200-205
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    • 2010
  • We report temperature and strain sensing characteristics of two kinds of in-line fiber interferometers. One interferometer consists of a section of Hollow Optical Fiber(HOF) spliced between two Photonic Bandgap Fibers(PBGF) and the other is built by splicing a section of HOF between two Large Mode Area-Photonic Crystal Fibers(LMA-PCF). To minimize the splice losses, we carefully optimized the heating time and arc current of the splicer so as not to collapse the air holes of the fiber. It is found that the first interferometer has a temperature sensitivity of 15.4 pm/$^{\circ}C$ and a strain sensitivity of 0.24 pm/${\mu}\varepsilon$. The other interferometer exhibits a temperature sensitivity of 17.4 pm/$^{\circ}C$ and a strain sensitivity of 0.2 pm/${\mu}\varepsilon$.

User's Voluntary Heating Behavior for the Programming of the Efficient Heating Mode of Smart Base Layer Clothing (스마트 베이스 레이어 의복의 효과적인 발열모드 설정을 위한 사용자의 자율적 가열행동 연구)

  • Lee, Heeran;Hong, Kyunghi;Lee, Yejin;Kim, Soyoung
    • Journal of the Korean Society of Clothing and Textiles
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    • v.41 no.5
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    • pp.872-882
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    • 2017
  • There are no specific guidelines on how to control the heat input for the heat generating smart base layer. This study investigated the mode of actuating heat pad attached to the base layer by performing a human wear test in a cold environment. Subjects participating in the test wore T-shirts, jumper and pants on the base layer with heating pads. Skin temperature, total time of heating and the number of switching for the heating mode were observed as the subject controlled the heating mode voluntarily. The comfortable range of skin temperature on the abdomen was larger than on the lower back. The subject felt hot and turned off the switch when the mean skin temperature of the abdomen was $48.8^{\circ}C$ and the lower back was $40.1^{\circ}C$. The total heating time and the number of actuating switching were larger for women than men. The voluntary action of heating for men with high cold sensitivity was significantly different from men with low cold sensitivity. Therefore, it is necessary (depending on gender and cold sensitivity) to set the heating mode differently for the automatic heat control of a future smart base layer.

Genetic variation of sensitivity to photoperiod and accumulated temperature in soybean mini core collection lines

  • Islam, Md Rasadul;Fujita, Daisuke;Zheng, Shao-Hui
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.77-77
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    • 2017
  • The sensitivities to photoperiod and temperature give guidance to choose an adaptable genotype for specific area in soybean production. However, there is insufficient information about the variation of sensitivities to photoperiod and temperature with wide genetic background. We investigated the sensitivities to photoperiod and temperature using 82 soybean mini core collection lines provided by NIAS gene bank of Japan. The seeds were sown on 28 May and 4 August in 2015, 24 May and 5 August in 2016 at field in Saga, Japan ($33^{\circ}$ 14' 32'' N, $130^{\circ}$ 17' 28'' E) for the early (average photoperiod and temperature: 15.2 h and $25.1^{\circ}C$) and late (13.6 h and $27.2^{\circ}C$) sowing respectively. The plants were also grown in the growth chamber under 12 h photoperiod with three temperature regimes (day/night temperature: $25/18^{\circ}C$, $28/22^{\circ}C$ and $33/28^{\circ}C$). Emergence date, days to first flower were recorded with 10 plants in the field and 2 plants in the growth chamber for each line. The data for daily average temperatures and photoperiodic hours were collected from weather station. The days from emergence to first flower open (DEF) were varied from 23-92 (2015 and 2016) in early sowing whereas 18-68 (2015) and 18-59 (2016) in late sowing. The shortened DEF in late sowing could be caused by both short photoperiod and high temperature in late sowing. However, the accumulated temperatures during emergence to first flower open (ATEF) were less variable in comparison with DEF, suggesting the ATEF is dependent mostly on the photoperiod. The ATEF were found same between early and late sowing in some early flowering lines (e.g. $686.7^{\circ}C$ and $687.6^{\circ}C$ in HEUKDAELIPS, $728.8^{\circ}C$ and $706.3^{\circ}C$ in WILLIAMS'82) which indicated that these would be insensitive to day length. In the growth chamber experiment, the variation in both DEF and ATEF was a little greater at low temperature ($25/18^{\circ}C$) but almost same at middle ($28/22^{\circ}C$) and high ($33/28^{\circ}C$) temperatures. Since the less differences in ATEF were found between the three temperatures, it is suggested that the temperature plays only a quantitative effect on the flower initiation, and the large ATEF in some lines may indicate the stronger photosensitivity even at 12 h or longer juvenile phase. Some lines with the lowest ATEF regardless of growth conditions, such as FISKEBY V, KE 32 (ATEF: 559.6-666.5, 587.7-709.5) might lack the sensitivities to both photoperiod and temperature. The results suggested that soybean genotypes has wider variation in sensitivity to photoperiod, whereas less variation to temperature.

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Origami inspired Temperature Sensor based on Stimuli-Responsive Hydrogel (종이접기 기반 자극 반응성 하이드젤 온도 센서 연구)

  • Na, Jun-Hee
    • Journal of Sensor Science and Technology
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    • v.26 no.1
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    • pp.35-38
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    • 2017
  • A thermally responsive hydrogel has reversibility with temperature during swelling. Here, we proposed origami inspired temperature sensor by using multi-layered hydrogel film. The formation of patterned stripes on microscale film drives bending to an angle that can be controlled linearly. Although temperature range was not wide, measured sensitivity of sensors has high resolution and accuracy. It providing a powerful platform for the design of sensitive sensors and that easily adapt other type of sensors in microscale.