• Title/Summary/Keyword: Temperature Differences

Search Result 2,998, Processing Time 0.034 seconds

Experimental Study of Natural Convection Due to Combined Buoyancy in a Rectangular Enclosure (직각 밀폐용기내의 복합부력에 의한 자연대류에 관한 실험적 연구)

  • 이진호;현명택
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.10 no.2
    • /
    • pp.247-256
    • /
    • 1986
  • An experimental investigation was conducted to study natural convection due to temperature and concentration differences between the two opposite end walls of a rectangular enclosure of aspect ratio 0.2. Flow motion in the enclosure appears as a uni-cell flow pattern for the relatively lower concentration and higher temperature differences and vice versa, while it appears as a multicell flow pattern for the comparable temperature and concentration differences. In the multi-cell flow regime, when the cellular flow motiion is very slow, vertical temperature differences within the cells are negligible while the vertical concentration differences are large. In addition, both the temperature and concentration differences are negligible across the interface between the slowly moving cells. For the fast moving cellular flow motion, on thel contrary, vertical temperature differences within the cells are large while the vertical concentration differences are negligible. In this case, temperature differences are negligible and the concentration differences are large across the interface between the fase moving cells.

Study on the Effect of Air Circulator on Temperature Distribution in an Oyster Mushroom Farm

  • Jeong, Won Geun;Lim, Hack Kyu;Kim, Tae Han
    • Journal of Biosystems Engineering
    • /
    • v.38 no.2
    • /
    • pp.81-86
    • /
    • 2013
  • Purpose: Recently, domestic and abroad consumption of mushroom has been increasing. Especially, oyster mushroom has been the most consumed product, sharing one third of the mushroom market. The air temperature differences between relative positions of the mushroom farms were needs to be minimal. However, in reality, the air temperature differences ranged from 2 to $5^{\circ}C$. Because of this, the mushrooms are non-uniform growth as well as decrease in both quality and quantity. Although air circulators have been employed by oyster mushroom farms to minimize air temperature differences, no experiments have been performed to illustrate the effect of the air circulators. Methods: This experiment is designed to analyze the effect of the air circulation by constructing a prototype air circulator and measuring the air temperature when the circulator was position at different heights (50 cm, 150 cm, 200 cm) from the floor in the center. Result: The horizontal plane air temperature of the first growing bed when the air circulator was installed 50cm above the floor in the center, once not using the air circulators and the other time using the air circulators, yielded the air temperature differences of $8.6^{\circ}C$ and $1.8^{\circ}C$ and deviations of 2.82 and 0.60, respectively. The third growing bed's air temperature differences were $10.0^{\circ}C$, $1.6^{\circ}C$ and deviations 3.28, 0.64, each respectively. These outcomes proved that the use of air circulators minimized the air temperature difference and deviation. The use of air circulators helped minimize the air temperature differences and the derivations in oyster mushroom farm. Conclusion: The use of air circulators helped balance the air temperature distribution in oyster mushroom farm.

Variation Characteristics of Hourly Atmospheric Temperature Throughout a Winter (동계 시각별 외기온의 변동 특성에 관한 연구)

  • Lee, Seung-Eon;Shon, Jang-Yeul
    • Solar Energy
    • /
    • v.12 no.2
    • /
    • pp.1-8
    • /
    • 1992
  • Identifying characteristics of heating and cooling systems requires estimation of thermal load of specific time interval, especially in cases that its system is operated intermittently, by using thermal storage, of in a partial load condition. Estimating the thermal load, however, needs to forecast hourly weather data variation. Hence, this paper attempts to examine characteristics of hourly ourdoor temperature variation as a preliminary research for the mathematical modeling of the hourly weather variation. Speculating characteristics of daily minimum and maximum temperature occurances, hourly outdoor temperature variation, and daily temperature differences in the increasing range ($07h{\sim}15h$) and decreasing range($15h{\sim}07h$), we were able to analyze changing patterns of daily temperature differences in each range in terms of daily solar amount, cloud ratio, and other weather data. Results from the multiple regression analysis enables us to conclude that daily differences in the increasing range are strongly affected last night temperature itself while the other range's differences are influenced by many weather data, which are solar amount, the variation of cloud, and the maximum temperature of the previous day.

  • PDF

Effects of Somatotype Characteristics on Body Temperature Control Reaction & Thermal Sensation (체형특성(體型特性)이 체온조절반응(體溫調節反應) 및 온열쾌적감(溫熱快適感)에 미치는 영향(影響))

  • Shim, Boo-Ja;Yoo, Hyun
    • Journal of Fashion Business
    • /
    • v.7 no.1
    • /
    • pp.27-37
    • /
    • 2003
  • This study is the first part of the research to reveal the effects of somatotype characteristics on body temperature control reaction as well as thermal sensation. Nine healthy female collegians (classified into 3 body types of thin, normal, and obese according to Rohrer index) living in Busan were chosen as the subjects. The following are the results: Significant differences of skin temperature appeared in the parts of epigastrium (thin/normal>obese), anterior forearm (normal>thin/obese), and anterior leg (obese > thin/normal) as well as mean skin temperature. Mean skin temperature temporarily dropped owing to the exercise but tended to recover as time went by. Skin temperature of normal/thin shows higher than obese type. The change of skin temperature was noticed in the order of forehead > epigastrium > anterior forearm > anterior leg > anterior thigh (obese type) ; epigastrium > forehead > anterior forearm > anterior thigh > anterior leg (normal type) ; epigastrium > forehead > anterior forearm > anterior thigh > anterior leg (thin type, before and after exercise); epigastrium > forehead > anterior forearm > anterior leg > anterior thigh (thin type, during exercise). Significant differences were shown in the temperature change inside clothes according to somatotypes. No significant differences were revealed in thermal sensation, moisture sensation, and comfortable sensation according to body types and time.

An Experimental Study on the Characteristics of Moxa Combustion in the Moxa Materials (재료(材料)에 따른 뜸의 연소(燃燒) 특성(特性)에 대한 연구(硏究))

  • Park, Young-Bae;Kang, Sung-Keel;Kim, Chang-Hwan;Koh, Hyung-Kyun;Oh, Hwan-Sup;Huh, Wung
    • The Journal of Korean Medicine
    • /
    • v.17 no.1 s.31
    • /
    • pp.222-233
    • /
    • 1996
  • In order to understand the stimulation quality of Artemisine Vulgaris Folium(Bong), Mori Ramulus(Sangi) and Persicae Ramulus(Dogi) combustion, and get the basic data for the development of electric moxibustion apparatus, the average temperature, peak temperature, average gradient temperature, maximum gradient temperature and combustion time of heating period on the three moxa materials were measured. 1. The average combustion temperature was high in order of Dogi, Sangi and Bong, and these were acknowledged to have a significant difference each other in the average temperature. 2. The peak combustion temperature among those was high in order of Dogi, Sangi and Bong, and Bong was acknowledged to have significant differences with Dogi and Sangi. Sangi and Dogi however were not acknowledged to have difference each other. 3. The average gradient temperature among those was high in order of Dogi, Sangi and Bong, and Bong was proved to have significant differences with Dogi and Sangi. Sangi and Dogi however were not proved to have difference each other. 4. The maximum temperature among those was high in order of Dogi, Sangi and Bong, bong was acknowledged to have signigicant differences with Dogi and Sangi, but Sangi and Dogi were not proved to have difference each other. 5. The combustion time was short in order of Dogi, Sangi and Bong. Bong was acknowledged to have significant differences with Dogi and Sangi, but Sangi and Dogi were not. In order to understand well the characteristics of combustion, it is required to have a quantitative interpretation of combustion calory, and, in the future, we expect it is required to have a consistent study for the clinical effectiveness and the mutual relationship according to the combustion characteristics.

  • PDF

Rewarming Intervention Program for Abdominal Surgery Patients (복부 수술 환자의 저체온 예방 중재 프로그램)

  • Ahn, Hye-Young;Eom, Mi-Ran
    • Journal of Korean Academy of Fundamentals of Nursing
    • /
    • v.17 no.2
    • /
    • pp.220-230
    • /
    • 2010
  • Purpose: This study was done to identify differences in three groups of operative patients (Forced Air Warming, Electrical Blanketrol, Control) for discomfort and pattern of body temperature during surgery and post operatively. Methods: The sample consisted of 3 randomized 3 groups of abdominal surgery patients admitted to an university hospital in D-city : The Bair Hugger and upper body blanket were used with the first group, electrical blanketrol with PVC Film with the second, and the third group was the control. ANOVA was used with the WIN SPSS 17.0 program to analyze the data. Results: Significant differences were found among the three groups for tympanic and esophageal body temperature at 1 hour after starting surgery. There was significant difference in tympanic body temperature during the 15 minute stay in the post anesthetic room. There were no significant differences in thermal discomfort while in the post anesthetic room. or There among the three groups for serum cortisol during surgery. Conclusion: According to the results of this study, application of a Bair Hugger or electrical blanketrol improves maintenance of body temperature of operative patients as well as body temperature of post operative patients, and is a clinically significant warming method providing a more consistent body temperature.

Influence of Heat Stress Temperature on Sympathetic Nerve Activities (Heat-stress 온도 적용이 교감신경활동에 미치는 영향)

  • Lim, Young-Eun;Yang, Eun-Young;Kim, Tae-Youl
    • Journal of the Korean Academy of Clinical Electrophysiology
    • /
    • v.5 no.2
    • /
    • pp.11-21
    • /
    • 2007
  • The purpose of this study were to investigate influence of heat stress temperature on sympathetic nerve activities. Subjects were 8 normal adults (4 men, 4 women, 21.36 years old). First sympathetic nerve activities were measured at the point that increase of core temperature stops at the state of applying normal thermic temperature (NIT; $34^{\circ}C$). After measurement, temperature of bathtub was increased to heat stress temperature (HST; $46^{\circ}C$) and sympathetic nerve activities were remeasured at the point that temperature increase stops. Sympathetic skin response (SSR) were analyzed using EMG, IR thermometer, and auto stethoscope. SSR latency showed significant differences at both palms by electrical stimulation to median nerve (p<.05). Electrical stimulation to forehead showed significant difference at left palm (p<.05) and electrical stimulation to navel showed significant difference at right palm (p<.05). Median nerve in changes of SSR amplitude showed significant differences at both palms in HST (p<.01). Electrical stimulation to navel showed significant difference at left palm (p<.05). Ts of forehead and xiphoid process showed significant differences (p<0.01). Tc of oral (p<0.05) and inner ear (p<0.01) showed significant differences. Pulse rate showed significant difference (<0.05). This study showed that immersion in HST had significant decrease of excitability in sympathetic nervous system compared to immersion in NTT.

  • PDF

Differences Between Facial Skin Temperature of the Paralyzed Side and Those of the Normal side in Essential Blepharospasm patients. (포륜진도 환자의 건측-환측 안면부 피부온도차이에 관한 연구)

  • Gang, Eun-Gyo;Seo, Hyeong-Sik
    • Journal of Pharmacopuncture
    • /
    • v.10 no.3
    • /
    • pp.113-119
    • /
    • 2007
  • Objectives Benign essential blepharospasm is a progressive neurological disorder characterized by involuntary muscle contractions and spasms of the eyelid muscles. The aim of this study is to provide evidence of differences between facial skin temperaure of the paralyzed side and normal side in Essential Blepharospasm patients. Methods The author studied 13 patients with Essential Blepharospasm. We measured skin temperature of the forehead, zygoma area of the paralyzed side and those of the normal side with The Digital Infrared thermal image. Results There were no significant facial skin temperature differences between the paralyzed side and normal side. Conclusions Thermography is a useful diagnostic tool. But we expect that it is essential to diagnose a disease correctly at an early stage and to find a prompt treatment by introducing and utilizing a simple nonivading diagnofic method other than Thermography.

Effect of Ondol Environment on Physiological Regponseg during Sleeping (II) The Actual Conditions of Bedclimate in Spring - (온돌환경이 수면시의 생리반응엔 미치는 영향 -봄철 수면시 침실내 온열환경과 침상기후-)

  • 이순원;권수애
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.21 no.3
    • /
    • pp.516-523
    • /
    • 1997
  • The actual conditions of bedclimate are investigated depending on the regions and housing styles used on ondol in spring. Sixty healthy men and women (30 of them live in apartment and 30 of them live in detached house, 20 of them live in Wonju, 20 of them live in Cheongiu and 20 of them live in Pusan). The results are as follows: 1) The differences of bedclothes thickness between spring and autumn were not significant. weight of sleep-wear in spring was less than those in the autumn. 2) In the spring, the temperature and humidity of bedroom, floor, on/under the mattress, were lower and the temperature inside the sleep-wear was higher than those in the autumn. 3) The differences of the temperature and humidity of bedroom, the bed climate, and the clothing microclimate were significant by the regions and housing styles in spring. The temperature of bedroom and inside sleep-wear, the humidity of bedroom and inside sleep- wear in the apartment were higher than those in the detached house. 4) The differences of comfort sensation on the bedroom conditions was significant by the regions, and the differences of thermal sensation was significant by the housing styles. Most subjects perceived warm and dry but comfortable.

  • PDF

Effect of Temperature on the Development of the Ash-gray Leaf Bug, Piesma maculata (Insecta, Hemiptera, Piesmatidae) (온도가 두줄명아주노린재의 발육에 미치는 영향 (곤충망, 매미목, 명아주노린재과))

  • Park, Pil Ryoun;Sang Ock Park
    • The Korean Journal of Ecology
    • /
    • v.6 no.1
    • /
    • pp.55-65
    • /
    • 1983
  • The authors reared the ash-gray leaf bug, Piesma maculata in the growth cabinet controlled as temperature groups of $15, 20, 25, 30, 40^{\circ}C$under condition of photoperiod 16L:8D, light intensity $510{\pm}240$ lus, relative humidity $65{\pm}3%$, and analyzed the effects of temperature on the development of the insect. The results are summarized as follow: There are highly significant differences the developmental periods for the temperature groups, and between the developmental periods for the developmental stages. The egg in the temperature of 15 and $40^{\circ}C$ was hatched, but the ecdysis was impossible. The thermal threshold was $12.34^{\circ}C$and the upper lethal temperature $40.39^{\circ}C$. The total developmental periods of egg to adulate in the temperature of 20, 25, 30 and $35^{\circ}C$are 40.52, 22.37, 15.91 and 13.00 days, respectively. That is, the developmental period was decreased, as the temperature was increased. In the developmental period for the developmental stages, the developmental period of egg stage was longer than that of 25, 30 and $35^{\circ}C$, and that of 25。C was longer than that of $35^{\circ}C$. But ther was not significant differences between the developmental periods for the other temperature group. The rate of hatch at$20^{\circ}C$is the greater value as 90%, and the rates of 25, 30 and $35^{\circ}C$ are 79, 79 and 67%, respectively. That is the rate of hatch was decreased, as the temperature was increased. The mortality in the temperature of $35^{\circ}C$ is the greatest value as 68%, and those of 30, 25 and $20^{\circ}C$are 59, 59 and 41%, respectively. That is, the mortality was increased, as the temperature was increased. There was not significantly differences between the developmental period of female and male.

  • PDF