• Title/Summary/Keyword: Temperature

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Characteristics of soil respiration temperature sensitivity in a Pinus/Betula mixed forest during periods of rising and falling temperatures under the Japanese monsoon climate

  • Oe, Yusuke;Yamamoto, Akinori;Mariko, Shigeru
    • Journal of Ecology and Environment
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    • v.34 no.2
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    • pp.193-202
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    • 2011
  • We studied temperature sensitivity characteristics of soil respiration during periods of rising and falling temperatures within a common temperature range. We measured soil respiration continuously through two periods (a period of falling temperature, from August 7, 2003 to October 13, 2003; and a period of rising temperature from May 2, 2004 to July 2, 2004) using an open-top chamber technique. A clear exponential relationship was observed between soil temperature and soil respiration rate during both periods. However, the effects of soil water content were not significant, because the humid monsoon climate prevented soil drought, which would otherwise have limited soil respiration. We analyzed temperature sensitivity using the $Q_{10}$ value and $R_{ref}$ (reference respiration at the average temperature for the observation period) and found that these values tended to be higher during the period of rising temperature than during the period of falling temperature. In the absence of an effect on soil water content, several other factors could explain this phenomenon. Here, we discuss the factors that control temperature sensitivity of soil respiration during periods of rising and falling temperature, such as root respiration, root growth, root exudates, and litter supply. We also discuss how the contribution of these factors may vary due to different growth states or due to the effects of the previous season, despite a similar temperature range.

The Relationships between Temperature Changes and Mortality in Seoul, Korea (서울시의 기온변화와 사망자수 간의 관련성 연구)

  • Lee, Sa-Ra;Kim, Ho;Yi, Seung-Muk
    • Journal of Environmental Health Sciences
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    • v.36 no.1
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    • pp.20-26
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    • 2010
  • Temperature change has been shown to affect daily mortality even though different analytical methods produce different results. The effect of air pollution on the relationship between the temperature and the mortality is not large, although differences exist between temperature models. The aim of this study was to examine how the temperature change affected the daily mortality in Seoul by comparing the results from the temperature model using two study periods: one from 1994 to 2007 and the other from 1997 to 2007. Generally mean temperature, minimum temperature and Q10 temperature was derived as an optimal model, even though there are differences between age and cause of death. The analysis of threshold using total mortalities in all ages from 1994 to 2007 and from 1997 to 2007 showed that the number of the deaths increased 7.02% (95% CI: 6.06~7.98) and 2.51% (95% CI: 1.83~3.19), respectively as the mean temperature increased $1^{\circ}C$ from a threshold temperature of $27.5^{\circ}C$ and $25.7^{\circ}C$ respectively. These results indicated that the temperature has less effect on the number of death than does an extreme heat wave period.

Temperature Control Improvement of Pressure Heating Roller for Flexible Flat Cable Production (Flexible Flat Cable 생산성 향상을 위한 가압용 히팅롤러의 온도제어개선)

  • Kim Jae Hak;Lee Ho Jung;Chun Keyoung Jin
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.7 s.172
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    • pp.155-163
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    • 2005
  • Pressure heating rollers with temperature control were mounted to a flat cable laminating machine (FCLM). Pressure heating rollers should be heated up to the setting temperature $(175^{\circ}C)$ and kept on to producing good quality flexible flat cables (FFC). Existing Pressure heating rollers took more than 70minutes to the setting temperature and did not keep on the setting temperature in production. Temperature controller, electric power controller, material and diameter of rollers and heat capacities were changed to improve the temperature control of the pressure heat rollers for better production of the FFC. Thus, the reaching time to the setting temperature (RT), temperature stability time (TST) and temperature hunting (TH) were measured and compared with the existing pressure rollers case. The RT of A roller was shortened by 50minutes, and B roller was shortened by 15minutes. The TST of A roller was shortened by 13minutes, and B roller was shortened by 15minutes. The THs of both A and B rollers were settled up to ${\pm}5^{\circ}C$. Finally, the productivity of the FCLM and the quality of the FFC were increased.

The Development of the Temperature Compensation Equipment to minimize Error in the Wireless Transmission System at 60GHz Band (60GHz대역 무선통신장애 해결을 위한 온도보상장치 개발)

  • Myung, Byung-Soo;Ku, Seong-Deag
    • Journal of the Korean Society of Industry Convergence
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    • v.8 no.2
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    • pp.97-104
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    • 2005
  • Usually, propagation attenuation of millimeter wave occurs by rainfall, snowfall, temperature, effect of pressure of air. In 60GHz wave band wireless communication network, temperature change becomes big factor of propagation loss department. Also, temperature change causes disturbance of 60GHz frequency at transceiver. In this study, we used 60GHz transceiver and found propagation loss of wireless path and operating frequency disturbance characteristics. In transceiver that there is no temperature compensated device, operating frequency of TX changed by 60.865GHz at temperature of $-5^{\circ}C$, and appeared by 60.730GHz when is $50^{\circ}C$. Therefore, operating frequency change width by temperature change are about 100MHz, greatly. But, in transceiver that there is temperature compensated device, operating frequency of TX changed by 60.830GHz at temperature of $-5^{\circ}C$, and appeared by 60.710GHz when is $50^{\circ}C$. Therefore, operating frequency change width by temperature change are about 20MHz. According to these result, we constructed between buildings examination wireless site for point to point wireless communication using 60GHz band transceivers who have do temperature compensated device, and investigated data transmission characteristics about ambient temperature change. Therefore, if use transceiver that have temperature compensated device, may overcome the wireless transmission error in 60GHz band wireless communication LAN networks despite of ambient temperature change.

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Factors Influencing Body Temperature in Elderly Surgical Patients (가온요법을 받은 노인 수술 환자의 체온과 영향요인)

  • Kwon, Mi Hee;Byeon, Young Soon
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.20 no.2
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    • pp.108-117
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    • 2013
  • Purpose: The purpose of this study was to identify the factors that affect body temperature in elderly operation patients using a warming method and to examine differences in post operative body temperature by characteristics of the patients. Methods: Data were collected from 200 patients, aged 65 years or more undergoing surgery with a warming method. The data were analyzed using descriptive statistics, t-test, ANOVA, Scheffe's test and multiple regression with the SPSS 18.0 Program. Results: The mean score for body temperature of elderly operation patients using a warming method after surgery was $36.1{\pm}0.6^{\circ}C$ including 74 patients with hypothermia and 126 patients with normal body temperature. The body temperature according to general characteristics differed by age and whether the surgery was emergency surgery or not. The body temperature according to surgery-related factors differed by anesthesia type, length of operation, anesthesia time, magnitude of surgical procedure, amount of fluid, transfusion requirements, and preoperative body temperature. Factors influencing body temperature were age, BMI, transfusion requirements and preoperative body temperature. Conclusion: The results indicate that age, BMI, transfusion requirements and preoperative body temperature significantly influenced on body temperature after surgery. Thus preoperative body temperature needs to be maintained through pre-warming as a nursing intervention.

Particle Size Analysis of Lead Aerosol with the use of 2730ppm Lead Nebulizing Solution for Inhalation Toxicology Study (흡입독성 연구를 위한 2730ppm 납 네뷸라이징 용액에서 발생된 에어로졸의 입경분석)

  • Jeung Jae Yeal;Kang Sung Ho;Kim Sam Tae;Lee Eun Kyoung;Song Young Sun;Lee Ki Nam
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.17 no.2
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    • pp.518-524
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    • 2003
  • Ultrasonic nebulizer with the application of new engineering methodology and the design of electronic circuit was made for lead inhalation toxicology study and 2730ppm lead nebulizing solution was used to generate lead aerosol. After modification of source and inlet temperatures, the results of particle size analysis for lead aerosol were as following. The highest particle counting for source temperature 20℃ was 39933.66 in inlet temperature 100℃ and particle diameter 0.75tLm. The highest particle counting for source temperature 50℃ was 39992.71 in inlet temperature 250℃ and particle diameter 0.75μm. The highest particle counting for source temperature 70℃ was 37569.55 in inlet temperature 50℃ and particle diameter 0.75μm. The ranges of geometric mean diameter(GMD) were 0.754-0.784μm for source temperature 2℃, 0.758-0.852μm for source temperature 50℃, and 0.869-1.060μm for source temperature 70℃. The smallest GMD was 0.754μm in source temperature 20℃ and inlet temperature 20℃, and the largest GMD was 1.060μm in source temperature 70℃ and inlet temperature 250℃. The ranges of geometric standard deviation(GSD) were 1.730-1.782 for source temperature 20℃, 1.734-1.894 for source temperature 50℃, and 1.921-2.148 for source temperature 70℃. The lowest GSD was 1.730 in source temperature 20℃ and inlet temperature 20℃, and the highest GSD was 2.148 in source temperature 70℃ and inlet temperature 250℃. Lead aerosol generated in this study was polydisperse. The ranges of mass median diameter(MMD) were 1.856-2.133μm for source temperature 20℃, 1.877-2.894μm for source temperature 50℃, and 3.120-6.109μm for source temperature 70℃. The smallest MMD was 1.856μm in source temperature 20℃ and inlet temperature 20℃, and the largest MMD was 6.109μm in source temperature 70℃ and inlet temperature 250℃. Slight increases for GMD, GSD, and MMD values were observed with same source temperature and increase of inlet temperature. MMD for inhalation toxicology testing in EPA guidance is less than 4μm. In this study, source temperature 20℃ and 50℃ with inlet temperature from 20℃ to 250℃ were conformed to the EPA guidance, but inlet temperature 20℃ and 50℃ for source temperature 70℃ were conformed EPA guidance. MMD for inhalation toxicology testing in OECD and EU is less than 3μm. In this study, source temperature 20℃ and 50℃ with inlet temperature from 20℃ to 250℃ were conformed to the EPA guidance, but none for source temperature 70℃.

STUDY ON PREDICTION OF THE INDUCED TEMPERATURE IN ENVIRONMENTAL TEST (얇은 평판의 환경시험에서 유도온도 예측에 대한 연구)

  • Lee, J.Y.;Baek, S.H.;Park, S.J.
    • Journal of computational fluids engineering
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    • v.13 no.4
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    • pp.24-32
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    • 2008
  • Environmental test is divided into operation test and storage test. The temperature of storage test is induced temperature which is considered with all sort of the heat source. Induced temperature is the temperature to be adapted to each item and platform and can be induced by computer simulation, laboratory, and real field test. We considered the induced temperature to be associated with solar heat source. In this research. First, we compared the induced temperature which be occurred by one experiment for thin plate in solar test chamber with the other one which be occurred by computer simulation to be SolidWorks 2007 COSMOS FloWorks. After this verification, we showed induced temperature which can be occurred when the test item is stored. Especially, we bring out the induced temperature by applying the ambient temperatures which is presented by MIL-STD-810F and brought out in preceding research.

Diode Temperature Sensor Array for Measuring and Controlling Micro Scale Surface Temperature (미소구조물의 표면온도 측정 및 제어를 위한 다이오드 온도 센서 어레이 설계)

  • Han, Il-Young;Kim, Sung-Jin
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.1231-1235
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    • 2004
  • The needs of micro scale thermal detecting technique are increasing in biology and chemical industry. For example, Thermal finger print, Micro PCR(polymer chain reaction), ${\mu}TAS$ and so on. To satisfy these needs, we developed a DTSA(Diode Temperature Sensor Array) for detecting and controlling the temperature on small surface. The DTSA is fabricated by using VLSI technique. It consists of 32 ${\times}$ 32 array of diodes (1,024 diodes) for temperature detection and 8 heaters for temperature control on a 8mm ${\times}$ 8mm surface area. The working principle of temperature detection is that the forward voltage drop across a silicon diode is approximately proportional to the inverse of the absolute temperature of diode. And eight heaters ($1K{\Omega}$) made of poly-silicon are added onto a silicon wafer and controlled individually to maintain a uniform temperature distribution across the DTSA. Flip chip packaging used for easy connection of the DTSA. The circuitry for scanning and controlling DTSA are also developed

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A Study on Autoignition of Granulated Activated Carbon with Change of Ambient Temperature (주위온도 변화에 따른 입상활성탄의 자연발화에 관한 연구)

  • 목연수;최재욱
    • Journal of the Korean Society of Safety
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    • v.7 no.4
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    • pp.45-53
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    • 1992
  • Sponataneous ignition characteristics for granulated activated carbon were observed by performing experiments at constant ambient temperature and varying the ambient temperature sinusoidally. In case of varying the ambient temperature sinusoidally, the amplitudes of temperature were 5$^{\circ}C$, 1$0^{\circ}C$ and 15$^{\circ}C$ respectively, and the period in each amplitude was varied at an interval of 30minutes from zero to 3hours. As the results of experiments at a constant ambient temperature, the critical spontaneous ignition temperature of the sample decreased as the sample vessel size increased. Apparent activation energy of the sample calculated from the Frank-Kamenetskii's thermal Ignition theory was 38.82[kca1/mo1] In case of varying the ambient temperature sinusoidally, the critical spontaneous ignition tempera-ture was lower than that at the constant ambient temperature, and the minimum critical spontaneous ignition temperature decreased with the amplitude of heating sinusoidal curve. At the same amplitude, the critical spontaneous ignition temperature decreased until it reached the minimum point and then in-creased as the period increased.

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Over-Temperature Protection Circuit Modeling Using MOSFET Rds(on) Temperature-Resistance Characteristics (MOSFET Rds(on) 온도-저항 특성을 이용한 과열보호회로 모델링)

  • Choi, Nak-Gwon;Lee, Sang-Hoon;Kim, Hyoung-Woo;Kim, Ki-Hyun;Seo, Kil-Soo;Kim, Nam-Kyun
    • Proceedings of the KIEE Conference
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    • 2005.07d
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    • pp.3019-3021
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    • 2005
  • In this paper we suggest a novel temperature detection method utilized in direct over-temperature protection circuit modeling. The suggested model detects temperature variation using Rds(on) characteristics of MOSFET, while the conventional methods are using extra devices such as a temperature sensor or an over-temperature detection transistor. The temperature-dependant MOSFET model is implemented using Spice ABM(Spice Analog Behavior Model). The direct over-temperature protection circuit was designed including it. We verified effectiveness of the temperature dependant Rds(on) model characteristics and performance of the direct over-temperature protection circuit on PSpice simulation

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