• Title/Summary/Keyword: Mean Temperature

Search Result 3,908, Processing Time 0.034 seconds

A Study of Low Cycle Fatigue Characteristics of 11.7Cr-1.1Mo Heat Resisting Steel with Mean Stress (Mean Stress를 고려한 11.7Cr-1.1Mo강의 고온저주기 피로특성에 관한 연구)

  • Hong, Sang-Hyuk;Hong, Chun-Hyi;Lee, Hyun-Woo
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.14 no.3
    • /
    • pp.133-141
    • /
    • 2006
  • The Low cycle fatigue behavior of 11.7Cr-1.1Mo heat-resisting steel has been investigated under strain-controlled conditions with mean stresses at room temperature and $300^{\circ}C$. For the tensile mean stress test, the initial high tensile mean stress generally relaxed to zero at room temperature, however, at $300^{\circ}C$ initial tensile mean stress relaxed to compressive mean stress. Low cycle fatigue lives under mean stress conditions are usually correlated using modifications to the strain-life approach. Based on the fatigue test results from different stain ratio of -1, 0, 0.5, and 0.75 at room temperature and $300^{\circ}C$, the fatigue damage of the steel was represented by using cyclic strain energy density. Total strain energy density considering mean stress indicated well better than not considering mean stress at $300^{\circ}C$. Predicted fatigue life using Smith-Watson-Topper's parameter correlated fairly well with the experimental life at $300^{\circ}C$.

Physiological Responses of the Human Body on a Change of the Floor Temperature in Indoor (인공기후실내의 바닥온도 변화에 의한 인체의 생리적 반응)

  • Choi, Young-Sik
    • Journal of the Korean Society of Industry Convergence
    • /
    • v.1 no.1
    • /
    • pp.21-30
    • /
    • 1998
  • The purpose of this study is to clarify the floor temperature on the human body and to estimate thermal comfort zone in a heated room. In order to evaluate the effects of floor heating, a series of experiments were carried out using Korean subjects. The following experiments were conducted: 1) to obtain the effective radiation area and configuration factors of the person in the sitting posture on a floor to get the mean radiant temperature, 2) to measure contacted area of the person to the floor to calculate conduction heat rate, 3) to measure convective heat transfer coefficient of the body and 4) to know the thermal comfort zone of indoor environment heated by ON-DOL. Subjects were exposed to the following conditions: combinations of air temperature $20^{\circ}C$, $22.5^{\circ}C$, $25^{\circ}C$, and floor temperature $20^{\circ}C$, $22.5^{\circ}C$, $25^{\circ}C$, $27.5^{\circ}C$, $30^{\circ}C$, $32.5^{\circ}C$, $35^{\circ}C$, $37.5^{\circ}C$, $40^{\circ}C$ under still air and 50% relative humidity in the controllable artificial climate chamber. To evaluate the effect of heat conduction between the body and a floor modified mean skin temperature was defined. Weighting coefficient to calculate mean skin temperature were modified with the contacted area. The experiments revealed a positive correlation between the modified operative temperature and the modified mean skin temperature. The modified mean skin temperature can indicate the effect of heat conduction between body and a floor surface.

  • PDF

Effectsd of posture on physiological thermal responses with Ondol heating system (온돌난방에서의 자세에 따른 온열생리적 반응의 성차)

  • 신정화;최정화
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.22 no.8
    • /
    • pp.1020-1031
    • /
    • 1998
  • This study was done to investigate thermal reponses and to obtain the basic information of thermal comfort by sex and posture under the Ondol heating system. Six healthy males and females were exposed to Ondol(Room Temp.: 25$\pm$1$^{\circ}C$, 50$\pm$10%R.H, Floor Temp.:30$\pm$1$^{\circ}C$) on the of posture such as sitting, lying aside and supine on the floor for 30 minutes after 30 minutes' control phase. During the experiment, rectal temperature, skin temperature of 10 areas, local sweating rate, clothing microclimate, subjective sensation were measured. Rectal temperature gradually decreased and mean skin temperature grad-ually increased both male and female in any posture. There was not significant difference between male and female in rectal temperature and mean skin temperature. There were significant difference among the postures in rectal temperature(p<0.001) and mean skin temperature(p<0.001). In lying aside and supine on the floor, appearances of change and changes in rectal temperature and mean skin temperature were large, changes of weight were small. In sitting on the floor, appearances of change and changes in rectal temperature and mean skin temperature were small, changes of weight were large. The trunk skin tem-perature was higher in female than in male, but the extremity skin temperature was higher in male than in female. In sitting on the floor, foot skin temperature(p<0.001) was higher than any other local skin temperature. In supine on the floor, back skin temperature(p<0.001) was higher than any other local skin temperature.

  • PDF

An Environmental Effect on Productivity of Flounder Culture Farms (넙치양식장 환경에 따른 생산성에 관한 연구)

  • Eh, Youn-Yang
    • The Journal of Fisheries Business Administration
    • /
    • v.42 no.3
    • /
    • pp.79-93
    • /
    • 2011
  • Water temperature of Oliver flounder farm affects Oliver flounder growth and mortality rate. In laboratory experimental tanks, optimal water temperature was $22.5^{\circ}C$($21{\sim}24^{\circ}C$) and cultivatable water temperature was $12{\sim}28^{\circ}C$. The purpose of this study is to identify applicable and useful water temperature of Oliver flounder farm in case of actual farming. The data applied in the analysis was collected from Jeju island. In the study, various analytical methods including productivity analysis, regression analysis, statistical analysis were conducted for 13 Oliver flounder culture farms. The result of analysis can be summarized as follows : First, growth rate on the Oliver flounder culture farms was related to mean of water temperature, variation of water temperature and low water temperature. Second, survival rate on the Oliver flounder culture farms was related to mean of water temperature. In case of including Oliver flounder stocking density, defined as the surface area of Oliver flounder per $m^2$ of water surface area, survival rate strongly related to mean of water temperature, variation of water temperature, cultivating capability and stocking density. Third, production weight per $m^2$ of water surface area was strongly related to mean of water temperature, low water temperature and cultivating capability. Growth rate and survival rate was analyzed into mediate variable character.

Comparison of the Meteorological Factors on the Forestland and Weather Station in the Middle Area of Korea

  • Chae, Hee Mun;Yun, Young Jo
    • Journal of Forest and Environmental Science
    • /
    • v.34 no.3
    • /
    • pp.249-252
    • /
    • 2018
  • Climate is one of most important environmental factors on the forest ecosystem. This study was conducted to analyze the characteristics of meteorological factors in the forest area and weather stations from July 2015 to June 2016 in Cheuncheon and Hongcheon of Kangwon Province in Korea. The HOBO data logger was installed for meteorological analysis in forests area (site 1 and site 2). The meteorological data from the HOBO data logger compared with meteorological data of the weather station. The meteorological data used for the analysis was monthly mean temperature ($^{\circ}C$), monthly mean minimum temperature ($^{\circ}C$), monthly mean maximum average temperature ($^{\circ}C$), and monthly mean relative humidity (%). As a result of this study, the mean temperature ($^{\circ}C$) of forest area was relatively lower than weather station which is the outside the forest area, and the mean maximum temperature ($^{\circ}C$) of weather station was relatively higher than that of forest area. The mean relative humidity (%) was higher in forest area than weather station.

Clinical Studies for the Development of Non-contact Thermometer to Take Easily the Body Temperature of Domestic Animals (가축에서 간이 체온측정 비접촉성 체온계 개발을 위한 임상적 연구)

  • 김용준;이대영;한경호
    • Journal of Veterinary Clinics
    • /
    • v.20 no.3
    • /
    • pp.357-363
    • /
    • 2003
  • These studies were carried out to develop non-contact thermometer to take easily the body temperature of domestic animals instead of taking rectal temperature. For the studies, 86 cattle, 57 horses, 72 pigs, 43 goats, and 42 dogs were used and body parts as neck, flank, axilla, lateral abdomen, gluteus, inguinal region, or jugular groove were chosen for taking temperature according to different species. Two types of commercial non-contact thermometers were used to take the temperature of certain body part and at the same time the rectal temperature using digital thermo-meter was taken to compare the difference of temperature between rectum and certain body part. The difference of mean temperature in cattle between rectum and axilla and flank were 0.52 and $2.41^{\circ}C$, respectively, using non-contact thermometer I, whereas $3.02^{\circ}C$ between rectum and flank using thermometer II. The difference of mean temperature in horses between rectum and axilla, gluteus, and jugular groove were 0.52, 1.49, and $0.26^{\circ}C$, respectively, using thermometer I, whereas 2.28 ane $0.92^{\circ}C$ between rectum and gluteus or jugular groove using thermometer II. The difference of mean temperature in swine between rectum and flank, inguinal region, and neck were 1.23, 0.21, and $0.8^{\circ}C$, respectively, using thermometer I, whereas 1.42, 0.711, and $1.25^{\circ}C$ using thermometer II The difference of mean temperature in goats between rectum and lateral abdomen and inguinal region were 1.02 and $0.12^{\circ}C$, respectively, using thermometer I, whereas 1.96 and $1.01^{\circ}C$ using thermometer II. The difference of mean temperature in dogs between rectum and lateral abdomen, inguinal region, and neck were 3.26, 0.24, and $2.37^{\circ}C$, respectively, using thermometer I, whereas 3.45, 0.56, and $2.61^{\circ}C$ using thermometer II.

A Study on the Physiological Properties of Skating Players : Skin Temperature and Clothing Temperature in Body Parts

  • Jeon, Hyang-ran
    • Fashion & Textile Research Journal
    • /
    • v.2 no.5
    • /
    • pp.423-429
    • /
    • 2000
  • This study was conducted to find out the relationship between skin temperature and clothing temperature in body parts. Four different kinds of fabrics were used in this experiment. These fabrics were a (Ny/Spun, 81.8/18.2%), b (Wool/Poly/span, 50/45/5%), (Wool/Ny/Span70/25/5) and d (Wool/Poly/Span 45/45/10%). The subjects skated at indoor ice rink where the length was 111.12 m, the temperature was $11{\pm}1^{\circ}C$ and the humidity was $70{\pm}10%$. The four an male professional skaters speed was $17{\pm}1$ seclm/lap. Physiological parameters were skin temperature at 4 body points (chest, upper arm, thigh, leg) and clothing temperature at chest was measured every 15 second. Experiment protocol was as follows: resting before skating (5 min.), skating (5 min.), and resting after skating (10 min.). The results were as follows; The mean skin temperature by fabrics shows b > a > d > c. The mean skin temperature began to decline little by little as soon as the subjects entered the indoor ice rink. After they rested for five minutes, they started skating and the mean skin temperature declined widely. After skating, the mean skin temperature increased step by step. It maintained the similar temperature. The value of skin temperature at body points shows Leg > Chest > Upper arm > Thigh. Because of the characteristics of skating uniforms, the skin temperature of the leg is the highest. The skating uniform was designed to have a protective portion in the leg. The chest produces the highest temperature in the body. The comparison of difference values in skin temperature show Thigh > Upper arm > Chest > Leg. While skating in a cold atmosphere, the largest difference value is clothing temperature. The clothing temperature is lower than the skin temperature during skating. The difference value of clothing temperature is larger than the skin temperature of the chest.

  • PDF

Evaluation of Thermal Comfort in Ceiling Cooling System (천장복사냉방의 온열쾌적성 평가에 관한 연구)

  • Lee, Ju-Youn
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.20 no.4
    • /
    • pp.287-293
    • /
    • 2008
  • The purpose of this study was to clarify the effects of air and ceiling temperatures on a type of ceiling cooling system that involves cool water circulation. The experiment is conducted in summer. The subjects (11 young females) are exposed to the following conditions: combinations of air temperatures $(27^{\circ}C,\;29^{\circ}C,\;31^{\circ}C)$ and ceiling temperature of $(22.7^{\circ}C,\;23.7^{\circ}C,\;24.7^{\circ}C)$ in still air and RH 50%. The following results were obtained; the thermal sensation vote is neutral at a mean skin temperature of $34.5^{\circ}C$. The ceiling temperature affected different parts of the body. For example, the forehead, scapula and abdomen produced different skin temperatures. Thermal comfort vote was rated as comfortable at high temperature environment. The satisfaction from the ceiling temperature was valued comfortable zone in this experiment. Mean skin temperature showing higher thermal neutrality temperature than existing studies for floor and wall radiation cooling results.

Metabolic Heat Production and Rectal Temperature of Newborn Calves

  • Mundia, C.M.;Yamamoto, S.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.10 no.3
    • /
    • pp.304-307
    • /
    • 1997
  • Rectal temperature (Tr), skin surface temperatures (Ts), and heart rate (HR) were measured continuously from birth (day 1) till day 7, while resting heat production (HP) was measured in a chamber on days 1, 3, 5 and 7, in order to study the characteristic variation of Tr in newborn calves by heat balance methods. Despite constant levels of milk being given to the newborn calves each day, daily mean resting HP was lowest on the day of birth, then increased to peak on day 3 and then decreased slightly thereafter. Daily mean HR was higher on days 2, 3 and 4, than on other days. Tr exhibited diurnal rhythms and daily mean Tr was low on day 1, high on day 3, and then decreased slightly after day 3. Daily average mean skin temperature (mTs) was similar on all days. Mean body temperature (Tb) exhibited diurnal rhythms and had a similar range between days, suggesting that heat balance and thermoregulation were carried out effectively on each day. The variation of Tb appeared to be synchronized with that of HP and suggested that newborn calves might use variations in the levels of Tb to facilitate the body's required levels of heart loss.

The relationship of mean temperature and 9 collected butterfly species' wingspan as the response of global warming

  • Na, Sumi;Lee, Eunyoung;Kim, Hyunjung;Choi, Seiwoong;Yi, Hoonbok
    • Journal of Ecology and Environment
    • /
    • v.45 no.4
    • /
    • pp.182-189
    • /
    • 2021
  • Background: Organism body size is a basic characteristic in ecology; it is related to temperature according to temperature-size rule. Butterflies are affected in various aspects by climate change because they are sensitive to temperature. Therefore, this study was conducted to understand the effect of an increase in temperature due to global warming on the wing of butterflies. Results: A total of 671 butterflies belonging to 9 species were collected from 1990 to 2016 in Seoul (336 specimens) and Mokpo (335 specimens). Consequently, as the mean temperature increased, the wing length of the species increased. However, there are exceptions that the Parnassius stubbendorfii, Pieridae canidia, and Pieris rapae wing length of Seoul increased, but the butterfly wing length of Mokpo decreased. Conclusions: The positive correlations between the butterfly wing length and mean temperature showed that the change of mean temperature for about 26 years affects the wing length of butterfly species. The exception is deemed to have been influenced by the limited research environment, and further studies are needed. We would expect that it can be provided as basic data for studying effect of climate change.