• Title/Summary/Keyword: Water Surrounding

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Investigation of Standard Error Range of Non-Contact Thermometer by Environment (외부 환경 변화에 의한 비 접촉 체온계의 오차 범위 측정)

  • Kim, Jeongeun;Park, Sangwoong;Choi, Heakyung
    • Journal of The Korean Society of Integrative Medicine
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    • v.8 no.4
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    • pp.307-321
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    • 2020
  • Purpose : A person infected by SARS-CoV2 may present various symptoms such as fever, pain in lower respiratory tract, and pneumonia. Measuring body temperature is a simple method to screen patients. However, changes in the surrounding environment may cause errors in infrared measurement. Hence, a non-contact thermometer controls this error by setting a correction value, but it is difficult to correct it for all environments. Therefore, we investigate device error values according to changes in the surrounding environment (temperature and humidity) and propose guidelines for reliable patient detection. Methods : For this study, the temperature was measured using three types of non-contact thermometers. For accurate temperature measurement, we used a water bath kept at a constant temperature. During temperature measurement, we ensured that the temperature and humidity were maintained using a thermo-hygrometer. The conditions of the surrounding environment were changed by an air conditioner, humidifier, warmer, and dehumidifier. Results : The temperature of the water bath was measured using a non-contact thermometer kept at various distances ranging from 3~10 cm. The value measured by the non-contact thermometer was then verified using a mercury thermometer, and the difference between the measured temperatures was compared. It was observed that at normal surrounding temperature (24 ℃), there was no difference between the values when the non-contact thermometer was kept at 3 cm. However, as the distance of the non-contact thermometer was increased from the water bath, the recorded temperature was significantly different compared with that of mercury thermometer. Moreover, temperature measurements were conducted at different surrounding temperatures and the results obtained significantly varied from when the thermometer was kept at 3 cm. Additionally, it was observed that the effect on temperature decreases with an increase in humidity Conclusion : In conclusion, non-contact thermometers are lower in lower temperature and dry weather in winter.

Analysis of Groundwater Conductivity and Water Temperature Changes in Greenhouse Complex by Water Curtain Cultivation (수막용수 사용으로 인한 시설재배지역의 지하수 수온과 전기전도도 변화 특성 분석)

  • Baek, Mi Kyung;Kim, Sang Min
    • Journal of The Korean Society of Agricultural Engineers
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    • v.65 no.6
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    • pp.93-103
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    • 2023
  • This study aimed to analyze the impact of water curtain cultivation in the greenhouse complexes on groundwater's electric conductivity and water temperature. The greenhouse complexes are mainly situated along rivers to secure water resources for water curtain cultivation. We classified the groundwater monitoring well into the greenhouse (riverside) and field cultivation areas (plain) to compare the groundwater impact of water curtain cultivation in the greenhouse complex. The groundwater observation network in Miryang, Gyeongsangnam-do, located downstream of the Nakdong River, was selected for the study area. As a result of analyzing the electric conductivity and water temperature, the following differences were found in the observed characteristics by region. 1) The electric conductivity and water temperature of the riverside area, where the permeability is high and close to rivers, showed a constant pattern of annual changes due to the influence of river flow and precipitation. 2) The flat land in general agricultural areas showed general characteristics of bedrock observation in the case of water temperature. Still, it seemed more affected by the surrounding well's water use and water quality. The electric conductivity did not show any particular trend and was influenced by the surrounding environment according to the location of each point.

To examine the construction plan of the lightening rod equipment for the intake tower of D-dam (D댐의 취수탑 피뢰설비 구축방안 검토)

  • Hong, Sung-Taek;Lee, Eun-Chun;Shin, Gang-Wook;Lee, Nam-Young
    • Proceedings of the KIEE Conference
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    • 2003.07a
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    • pp.290-292
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    • 2003
  • The intake tower of D-dam located in a mountainous area positioned in the left side of the dam and its structure installed alone on the water surface then, can become target of direct lightening. To protect the intake tower from the direct lightening and indirect-lightening, lightening rod installed in the top area of the intake tower and ground pole laid under the surrounding ground. however, because the surrounding ground almost consists of a rock, it is very difficult to obtain the grounding resistance. It is main object to examine the construction plan of the optimum lightening rod equipment and ground pole with measuring the earth specific resistance of the around of the intake tower which is the scheduled area to lay the ground pole with the Wenner's 4-electric pole method and the Schlumberger's method. and using the analysis tool, ESII.

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Current and Future Water Demand in Communes Surrounding Kibira National Park in Burundi (아프리카 부룬디의 Kibira 국립공원 인근 지역의 물수요 예측)

  • Bankuwiha, Melchiade;Kang, Daeseok;Sung, Kijune
    • Journal of Environmental Impact Assessment
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    • v.24 no.1
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    • pp.78-86
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    • 2015
  • Water plays the fundamental role in sustaining the living system. Water scarcity is mostly experienced dramatically by people living in poverty, most of them in rural areas and often in the poorest countries. Burundi has been identified as one of those countries. This study aimed to analyze and estimate the current and future water demands in the seven communes surrounding Kibira National Park (KNP) in Burundi. Sectors such as households, livestock, agricultural production and industry as the key water users in the study area were considered. The results showed an alarming increase in future water demand. Water demand by food crops increased to $288,779,060m^3/yr$ in 2020 and $306,018,348m^3/yr$ in 2050. Agricultural sector will be demanding the major available water in the seven communes surrounding Kibira National Park except Muruta and Bukeye which showed that water demand for tea industry was the highest in 2050. The water resources could be the greatest challenges for the overall development of the communities surrounding Kibira National Park. The current water resources may not be enough and therefore may not be able to meet the needs of those seven communities around KNP.

The tunnel model tests of material development in different surrounding rock grades and the force laws in whole excavation-support processes

  • Jian Zhou;Zhi Ding;Jinkun Huang;Xinan Yang;Mingjie Ma
    • Geomechanics and Engineering
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    • v.36 no.1
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    • pp.51-69
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    • 2024
  • Currently, composite lining mountain tunnels in China are generally classified based on the [BQ] method for the surrounding rock grade. Increasingly, tunnel field construction is replicated indoors for scale down model tests. However, the development of analogous materials for model tests of composite lining tunnels with different surrounding rock grades is still unclear. In this study, typical Class III and V surrounding rock analogous materials and corresponding composite lining support materials were developed. The whole processes of excavation-support dynamics of the mountain tunnels were simulated. Data on the variation of deformations, contact pressures and strains on the surrounding rock were obtained. Finally, a comparative analysis between model tests and numerical simulations was performed to verify the rationality of analogous material development. The following useful conclusions were obtained by analyzing the data from the tests. The main analogous materials of Class III surrounding rock are barite powder, high-strength gypsum and quartz sand with fly ash, quartz sand, anhydrous ethanol and rosin for Class V surrounding rock. Analogous materials for rockbolts, steel arches are replaced by aluminum bar and iron bar respectively with both shotcrete and secondary lining corresponding to gypsum and water. In addition, load release rate of Class V surrounding rock should be less than Class III surrounding rock. The fenestration level had large influence on the load sharing ratio of the secondary lining, with a difference of more than 30%, while the influence of the support time was smaller. The Sharing ratios of secondary lining in Class III surrounding rock do not exceed 12%, while those of Class V surrounding rock exceed 40%. The overall difference between the results of model tests and numerical simulations is small, which verifies the feasibility of similar material development in this study.

Investigation on Water Leakage-Induced Tunnel Structure and Ground Responses Using Coupled Hydro-Mechanical Analysis (수리역학 연계해석을 이용한 누수로 인한 터널 구조물 및 지반 거동의 분석)

  • Dohyun Park
    • Tunnel and Underground Space
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    • v.33 no.4
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    • pp.265-280
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    • 2023
  • Water leakage in tunnels is a defect that can affect tunnel stability and the ground movement by changing the stress and pore water pressure of the surrounding ground. Long-term or large-scale water leaks may lead to damage of tunnel structure and the surrounding environment, such as tunnel lining instability and ground surface settlement. The present study numerically investigated the effects of water leakage on the structural stability of a tunnel and the ground behavior. The tunnel was assumed to be under undrained conditions for preventing the inflow of the surrounding water and leaks occurred in the concrete lining after completion of the tunnel construction. A coupled hydro-mechanical analysis using a TOUGH-FLAC simulator developed in Python was conducted for assessing the leakage induced-behavior of the tunnel structure and ground under different conditions of the amount and location of water leak. Additionally, the effect of hydro-mechanical coupling terms on the results of coupled response was investigated and discussed.

An Algorithm for Leak Locating using Coupled Vibration of Pipe-Water (배관-유체 연성진동을 이용한 누수지점 탐지알고리듬 개발연구)

  • Lee, Yeong-Seop;Yun, Dong-Jin
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.985-990
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    • 2004
  • Leak noise is a good source to identify the exact location of a leak point of underground water pipelines. Water leak generates broadband noise from a leak location and can be propagated to both directions of water pipes. This sound propagation due to leak in water pipelines is not a non-dispersive wave any more because of the surrounding pipes and soil. However, the necessity of long-range detection of this leak location makes to identify low-frequency acoustic waves rather than high frequency ones. Acoustic wave propagation coupled with surrounding boundaries including cast iron pipes is theoretically analyzed and the wave velocity was confirmed with experiment. The leak locations were identified both by the acoustic emission (AE) method and the cross-correlation method. In a short-range distance, both the AE method and cross-correlation method are effective to detect leak position. However, the detection for a long-range distance required a lower frequency range accelerometers only because higher frequency waves were attenuated very quickly with the increase of propagation paths. Two algorithms for the cross-correlation function were suggested, and a long-range detection has been achieved at real underground water pipelines longer than 300m.

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Damping Effects of a Flexible Structure Interacting with Surrounding Acoustic Fluid (주변 음장과 연동하는 탄성 구조체의 감쇠 효과)

  • Lee, Moon-Seok;Park, Youn-Sik;Park, Young-Jin
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.04a
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    • pp.101-105
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    • 2008
  • A flexible structure submerged in acoustic fluid is affected by its surrounding fluid. In transient response of a submerged structure, the coupled effect between structures and surrounding fluid emerges as damping and added mass at early and late time, respectively. Therefore, the characteristics of submerged structure such as natural frequencies and damping coefficients are changed by its surrounding fluid. In this paper, the analytic modal equation of a spherical shell surrounded by water and air is dealt with. Through the example, the damping coefficients and natural frequencies of flexible structures are studied for various external acoustic fluid and structures.

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Damping Effects of a Flexible Structure Interacting with Surrounding Acoustic Fluid (주변 음장과 연동하는 탄성 구조체의 감쇠 효과)

  • Lee, Moon-Seok;Park, Youn-Sik;Park, Young-Jin
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.18 no.7
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    • pp.718-724
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    • 2008
  • A flexible structure submerged in acoustic fluid is affected by its surrounding fluid. In this case, the coupling effects between structures and surrounding fluid have an effect on the submerged structure as external force and change impedance of acoustic domain. Therefore, the coupling effects by its surrounding fluid complicatedly change the characteristics of a submerged structure such as natural frequencies and damping coefficients. In this paper, using the analytic modal equation of a spherical shell surrounded by water and air, the complex changes of damping coefficients and natural frequencies of submerged structures are studied for various external acoustic fluid and structures.

Time Delay Estimation for the Identification of Leak Location (시간지연 추정을 통한 누수위치 식별 연구)

  • Lee, Young-Sup;Yoon, Dong-Jin;Kim, Chi-Yup
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.11a
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    • pp.327-332
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    • 2004
  • Leak noise is a good source to identify the exact location of a leak point of underground water pipelines. Water leak generates broadband noise from a leak location and can be propagated to both directions of water pipes. This sound propagation due to leak in water pipelines is not a non-dispersive wave any more because of the surrounding pipes and soil. However, the necessity of long-range detection of this leak location makes to identify low-frequency acoustic waves rather than high frequency ones. Acoustic wave propagation coupled with surrounding boundaries including cast iron pipes is theoretically analyzed and the wave velocity was confirmed with experiment. The leak locations were identified both by the acoustic emission (AE) method and the cross-correlation method. In a short-range distance, both the AE method and cross-correlation method are effective to detect leak position. However, the detection for a long-range distance required a lower frequency range accelerometers only because higher frequency waves were attenuated very quickly with the increase of propagation paths. Two algorithms for the cross-correlation function were suggested, and a long-range detection has been achieved at real underground water pipelines longer than loom.

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