• Title/Summary/Keyword: CHANGE OF TEMPERATURE

Search Result 9,993, Processing Time 0.036 seconds

A Study on Cooling Characteristics of Low Temperature Thermal Storage Material with Additives (첨가제를 첨가한 저온축열물질의 냉각특성에 대한 연구)

  • Chung, Nak-Kyu;Kim, Jin-Heung;Chung, Jong-Hun;Kim, Chang-Oh;Kang, Seung-Hyun
    • Proceedings of the KSME Conference
    • /
    • 2004.11a
    • /
    • pp.1746-1750
    • /
    • 2004
  • The objective of this study is to investigate the effect of supercooling repression on the clathrate compound by adding additives. For this purpose, phase change temperature and supercooling were measured when additives added to TMA30wt% clathrate for heat source temperature of $-6^{\circ}C$. The experimental results show that the phase change temperature with the chloroform of 0.1wt% is higher by $0.3^{\circ}C$ than TMA30wt% and the supercooling with the surfactant 0.1wt% is reduced by $9.2^{\circ}C$.

  • PDF

Experimental Research Application to each Types of Insulation Materials in Rural Houses (농촌주택의 단열 재료별 현장 적용을 위한 실험 연구)

  • Kwon, Soon-Chan;Kim, Eun-Ja
    • Journal of the Korean Institute of Rural Architecture
    • /
    • v.19 no.4
    • /
    • pp.57-65
    • /
    • 2017
  • Life quality in farming areas is declining these days on account of decrease in population with the outflow of young generations, advent of aging society, and also lack of social and physical infrastructure. To reverse this, the central and local governments have been devising policies in many ways; however, the vulnerable class in farming area suffering from financial difficulty is not supported with that properly. The results of applying insulation materials applicable to rural houses, EPS, e-board, and glass wool, actually to rural houses are summed as follows. EPS is the most inexpensive among the three installations in terms of material cost and expenses. The indoor and outdoor temperature difference increased from $0.9^{\circ}C$ to $2.5^{\circ}C$, and the temperature change reduced as $0.04^{\circ}C$. With e-board, the indoor and outdoor temperature difference increased from $3.3^{\circ}C$ to $7.5^{\circ}C$; however, the temperature change increased as $0.09^{\circ}C$. Unlike the other two methods, glass wool requires the additional installation of wooden frames. The material cost is highest, and the indoor and outdoor temperature difference increased from $1.1^{\circ}C$ to $8.0^{\circ}C$, and the temperature change reduced as $0.01^{\circ}C$. According to the results of measuring temperature, glass wool's temperature difference is measured to be the highest, but temperature change is found to be the most effective in EPS. Among the three insulation methods, EPS is the most economically advantageous as the material supply is easy and the cost is low. The material is easily processible, so ordinary town residents can install it easily, and it is effective at improving insulation performance, too. But this method cannot be applied when the house has walls that are not even. Also, as the insulator is thick, after the installation, the living space may be narrower as a result.

Predicting the high temperature effect on mortar compressive strength by neural network

  • Yuzer, N.;Akbas, B.;Kizilkanat, A.B.
    • Computers and Concrete
    • /
    • v.8 no.5
    • /
    • pp.491-510
    • /
    • 2011
  • Before deciding if structures exposed to high temperature are to be repaired or demolished, their final state should be carefully examined. Destructive and non-destructive testing methods are generally applied for this purpose. Compressive strength and color change in mortars are observed as a result of the effects of high temperature. In this study, ordinary and pozzolan-added mortar samples were produced using different aggregates, and exposed to 100, 200, 300, 600, 900 and $1200^{\circ}C$. The samples were divided into two groups and cooled to room temperature in water and air separately. Compression tests were carried out on these samples, and the color change was evaluated by the Munsell Color System. The relationships between the change in compressive strength and color of mortars were determined by using a multi-layered feed-forward Neural Network model trained with the back-propagation algorithm. The results showed that providing accurate estimates of compressive strength by using the color components and ultrasonic pulse velocity design parameters were possible using the approach adopted in this study.

A study on sensing for abnormality of BUS BAR in motor control center (모터컨트롤센터의 BUS BAR 이상 감지를 위한 실험적 연구)

  • Kim, Sung-Dae
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.12 no.12
    • /
    • pp.5838-5842
    • /
    • 2011
  • The study mainly aims to explore how deterioration of motor control center, namely MCC, and vibration put impact on temperature of bus bar as well as temperature change of bolt-nut joint. The motor control center consists of three internal parts (i.e. R, S, T) which are for motor operation of high capacity. Two dimensional mechanism for measuring temperature was designed and manufactured with infrared temperature sensor. Installing it in inner motor control center enabled researcher to monitor temperature of bus bar as well as amount of change of current regularly. Temperature change of bus bar according to load was primarily examined based on a bolted joint in the experiment. It was clearly verified that temperature change of bus bar was proportional to current consumption. Therefore, installing non-contact two dimensional mechanism for measuring temperature in motor control center would be expected to prevent temperature rise owing to overload current and power outage as well as fire accident which can be triggered by poor electrical contact.

Forecasting Prices of Major Agricultural Products by Temperature and Precipitation (기온과 강수량에 따른 주요 농산물 가격 예측)

  • Kun-Hee Han;Won-Shik Na
    • Journal of Advanced Technology Convergence
    • /
    • v.3 no.2
    • /
    • pp.17-23
    • /
    • 2024
  • In this paper, we analyzed the impact of temperature and precipitation on agricultural product prices and predicted the prices of major agricultural products using TensorFlow. As a result of the analysis, the rise in temperature and precipitation had a significant effect on the rise in prices of cabbage, radish, green onion, lettuce, and onion. In particular, prices rose sharply when temperature and precipitation increased simultaneously. The prediction model was useful in predicting agricultural product price changes due to climate change. Through this, agricultural producers and consumers can prepare for climate change and prepare response strategies to price fluctuations. The paper can contribute to understanding the impact of climate change on agricultural product prices and exploring ways to increase the stability and sustainability of agricultural product markets. In addition, it provides important data to increase agricultural sustainability and ensure economic stability in the era of climate change. The research results will also provide useful insights to policy makers and can contribute to establishing effective agricultural policies in response to climate change.

Temperature Change Analysis for Land Use Zoning Using Landsat Satellite Imagery (Landsat위성영상에 의한 용도지역 온도변화분석)

  • Jung, Gil-Sub;Koo, Seul;Yoo, Hwan-Hee
    • Journal of Korean Society for Geospatial Information Science
    • /
    • v.19 no.2
    • /
    • pp.55-61
    • /
    • 2011
  • The land use has been changed artificially and caused the result of temperature increase of city compared with the outside of city or region of park and forest. The purpose of this research is to analyze the change of the urban surface temperature with land use zoning in Jinju using Landsat TM/$ETM^+$ imagery and to provide the correlation between NDVI(Normalized Difference Vegetation Index) and urban surface temperature change. The results presented that the spatial distribution of urban surface temperature was depending on the change of NDVI values on land use zoning. Considering to the average temperature by land use zoning, industrial area was the highest temperature but green area was the lowest temperature. Also as a result of comparing the correlation between surface temperature and NDVI, the green and residential area had higher correlation values than the commercial and industrial area. These results will be played a part as one of the major factors for implementing the sustainable urban planning considering the urban heat island effect problem.

A study on the Fabrication and Characteristics of SAW Temperature Sensor using piezoelectric material (압전재료를 이용한 SAW 온도센서의 제작 및 특성에 대한 연구)

  • 박재홍;김재환
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2004.05a
    • /
    • pp.563-567
    • /
    • 2004
  • In this paper, a remote temperature sensor based on surface acoustic wave is introduced and the issues on design, manufacturing, and test of the sensor are addressed. SAW sensors having single and double electrode are prepared on the 128$^{\circ}$ YX-LiNbO$_3$ Substrate. The frequency responses of SAW sensors on the temperature change are compared. To measure the change of center frequency, two center frequencies on the 3dB and 20dB are measured and compared. Since the center frequency on the temperature change from -30$^{\circ}C$ to 80$^{\circ}C$ is linearly changed, the SAW sensor is applicable to the temperature sensor.

  • PDF

Analysis of Sensitivity and Vulnerability of Endangered Wild Animals to Global Warming (지구 온난화에 따른 국내 멸종위기 야생동물의 민감도 및 취약성 분석)

  • Kim, Jin-Yong;Hong, Seongbum;Shin, Man-Seok
    • Journal of Climate Change Research
    • /
    • v.9 no.3
    • /
    • pp.235-243
    • /
    • 2018
  • Loss of favorable habitats for species due to temperature increase is one of the main concerns of climate change on the ecosystem, and endangered species might be much more sensitive to such unfavorable changes. This study aimed to analyze the impact of future climate change on endangered wild animals in South Korea by investigating thermal sensitivity and vulnerability to temperature increase. We determined thermal sensitivity by testing normality in species distribution according to temperature. Then, we defined the vulnerability when the future temperature range of South Korea completely deviate from the current temperature range of species distribution. We identified 13 species with higher thermal sensitivity. Based on IPCC future scenarios RCP 4.5 and RCP 8.5, the number of species vulnerable to future warming doubled from 3 under RCP4.5 to 7 under the RCP8.5 scenario. The species anticipated to be at risk under RCP 8.5 are flying squirrel (Pteromys volans aluco), ural owl (Pteromys volans aluco), black woodpecker (Dryocopus martius), tawny owl (Strix aluco), watercock (Gallicrex cinerea), schrenck?s bittern (Ixobrychus eurhythmus), and fairy pitta (Pitta nympha). The other 10 species showing very narrow temperature ranges even without normal distributions and out of the future temperature range may also need to be treated as vulnerable species, considering the inevitable observation scarcity of such endangered species.

A Study of Physiology Signal Change by Air Conditioner Temperature Change (에어컨 온도변동에 따른 생리신호 변화에 관한 연구)

  • Kum, Jong-Soo;Kim, Dong-Gyu;Kim, Hyung-Chul
    • Journal of Fisheries and Marine Sciences Education
    • /
    • v.19 no.3
    • /
    • pp.502-509
    • /
    • 2007
  • This study evaluates thermal comfort by air conditioner temperature raising at the point of time that human body begins to adapt. Thermal comfort according to change of time enters by uncomfortable area gradually at general cold room temperature that magnetic pole is in human body. However, can know that keep continuous thermal comfort in case raise temperature in human body adaptation visual point. Experiments were performed in environmental chamber. Subjects were selected 4 men and 4 women whose life cycle were proved that are similar. The subjects stay in the pretesting room during the 30 minutes and enter the testing room under each experiment conditions. During the experiment, brain wave, electrocardiogram, blood pressure and thermal comfort and sensation responses were measured. In this study, physiological and psychological responses correspond under temperature raising at human body adaptation.

A study on the Fabrication and characterization of temperature Sensor using surface acoustic wave (표면 탄성파를 이용한 온도센서의 제작 및 특성에 대한 연구)

  • Park Jae-Hong;Kim Jae-Hwan
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.23 no.4 s.181
    • /
    • pp.139-145
    • /
    • 2006
  • This paper presents the design and manufacturing of a sensor using SAW and delay line in order to measure temperature. SAW sensors having single and double electrodes are manufactured on the $128^{\circ}YX-LiNbO_3$ substrate, and its process is addressed. Before manufacturing, the device is simulated using a commercial finite element program. The frequency responses of the saw sensor on the temperature change is measured. Since the center frequency on the temperature change from $-30^{\circ}C$ to $80^{\circ}C$ is linearly changed, the saw sensor is applicable to measure the temperature change or strain variation.