• Title/Summary/Keyword: Uniform Temperature

Search Result 1,836, Processing Time 0.034 seconds

Evaluation of Indoor Thermal Environment and Thermal Sensation in Traditional Ondol Room (전통온돌방의 실내온열환경 및 온열감에 관한 연구)

  • 김난행;손장열
    • Journal of the Korean housing association
    • /
    • v.15 no.2
    • /
    • pp.19-25
    • /
    • 2004
  • The aim of the research was to evaluate the characteristics of indoor thermal environment and thermal sensation in the traditional Ondol room. Indoor thermal factors including air temperature, operative temperature, floor surface temperature, relative humidity, PMV, OT were measured, and survey was carried out to understand subjective responses of resident's related to indoor thermal environment in Ondol room. The analysed houses are: the Chung hyo dang(the head house of Ryu family in Andong) and the Pyeung won jung(the traditional house in Yesan). The purpose of the survey was to know the relationship between resident's sensation and thermal environmental indicators such as air temperature, relative humidity, floor surface temperature, OT. The experimental results have pointed out how Ondol room may lead to comfortable and uniform indoor thermal environments.

Distribution of Cathodic Protection Potential for Concrete Slab Specimens at Diverse Environmental Conditions

  • Jin, Chung-Kuk;Jeong, Jin-A
    • International Journal of Ocean System Engineering
    • /
    • v.3 no.2
    • /
    • pp.90-94
    • /
    • 2013
  • This study represents the recent laboratory results from cathodic protection (CP) system with the use of sacrificial anodes at different environmental conditions (temperature of $10^{\circ}C$ and $40^{\circ}C$). Specimens were slab type with a dimension of $500mm{\times}50mm{\times}100mm$, and concrete cover thickness were 25mm. Zinc mesh and/or bulk type anodes were installed at the center of specimen to confirm the distance that CP system has influences on the specimen to distribute uniform CP current to rebar. Two different kinds of temperature condition were applied to verify the effect of temperature. Experiments were conducted for 60 days, and the distribution of potential and current that supplied from anode to rebar was measured. From the results, CP potential was varied with time, and temperature played an important role in CP potential variations. Current was also changed with time, and current distribution could be improved by installing additional bulk type anode.

Characteristics of Dielectries in $SF_6$ Accoding to a change in Temperature (온도변화에 따른 $SF_6$ 가스의 절연특성)

  • Lee, Bok-Hee;Kim, Hoe-Gu;Park, Geon-Hun;Lee, Kyu-Sun;Kim, Dong-Sung
    • Proceedings of the KIEE Conference
    • /
    • 2007.07a
    • /
    • pp.1436-1437
    • /
    • 2007
  • This paper presents the experimental results of the dielectric characteristics with temperature changes under highly non-uniform electric field in $SF_6$ gas. The impulse preliminary breakdown developments were investigated by the measurement of predischarge current and breakdown voltage. As a result, the first stremer corona is initiated at the tip of needle electrode, and bridges the test gap. Also the first stremer corona onset and breakdown voltages the negative polarity was much higher than that in the positive polarity in same temperature. In addition, the varition of temperature have a little effect on the positive polarity. On the other hand, in some cases negative polarity corona onset and breakdown voltages increased with increasing a high temperature.

  • PDF

Breakdown Characteristics of $SF_{6}/N_{2}$ Gas Mixtures According to a change in Temperature (온도변화에 따른 $SF_{6}/N_{2}$ 혼합가스의 절연특성)

  • Lee, Bok-Hee;Li, Feng;Choi, Jong-Hynk;Baek, Young-Hwan;Jeong, Dong-Chul;Kim, Seong-Weon
    • Proceedings of the KIEE Conference
    • /
    • 2007.07a
    • /
    • pp.1455-1456
    • /
    • 2007
  • This paper presents the experimental results on impulse breakdown characteristics under a highly non-uniform electric field in $SF_{6}/N_{2}$ gas mixtures according to a change in temperature. Test temperature ranges from $-25^{\circ}C$ to $25^{\circ}C$. The impulse predischarge breakdown developments are investigated by the measurements of current pulse and discharge luminous events. As a result, the predischarge development mechanisms for both positive and negative polarities are same. When increasing the temperature, breakdown voltage due to lightning impulse voltage is increased in negative polarity. On the other hand, when increasing the temperature, breakdown voltage due to lightning impulse voltage is not changed in positive polarity.

  • PDF

The temperature distributions of the curing space according to blocking the opening of gang-form at the apartment in the cold weather (동절기 공동주택 갱폼 개구부 천막보양에 따른 보양 온도 분포 분석)

  • Cho, Hong-Bum;Song, Jin-Hee;Kim, Young-Sun;Choi, Ji-Su;Lee, Kyu-Nam
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2022.04a
    • /
    • pp.140-141
    • /
    • 2022
  • CFD analysis was performed to analyze the temperature distribution of the inner space of the curing house according to blocking the opening of the gang-form with a tent in case of concrete pouring and heat curing of the apartment house during the winter season. If the gang-form opening is closed with a tent during internal heating using a hot air blower in the winter, the internal temperature rises compared to the non-reserved due to air-tightness of the curing spaces, and uniform temperature distribution can be ensured. In addition, it is possible to increase curing efficiency by reducing the amount of heat supplied and shortening the heating time.

  • PDF

Numerical and experimental investigation on the temperature distribution of steel tubes under solar radiation

  • Liu, Hongbo;Chen, Zhihua;Zhou, Ting
    • Structural Engineering and Mechanics
    • /
    • v.43 no.6
    • /
    • pp.725-737
    • /
    • 2012
  • The temperature on steel structures is larger than the ambient air temperature under solar radiation and the temperature distribution on the affected structure is non-uniform and complicated. The steel tube, as a main structural member, has been investigated through experiment and numerical analysis. In this study, the temperature distribution on a properly designed steel tube under solar radiation is measured. A finite element transient thermal analysis method is presented and verified by the experimental results and a series of parametric studies are carried out to investigate the influence of various geometric properties and orientation on the temperature distribution. Furthermore, a simplified approach is proposed to predict the temperature distribution of steel tube. Based on both the experimental and the numerical results, it is concluded that the solar radiation has a significant effect on the temperature distribution of steel tubes. Under the solar radiation, the temperature of steel tubes is about $20.6^{\circ}C$ higher than the ambient air temperature. The temperature distribution of steel tubes is sensitive to the steel solar radiation absorption, steel tube diameter and orientation, but insensitive to the solar radiation reflectance and thickness of steel tube.

Effect of the Temperature Change on the Cone Tip Resistance (지중의 온도변화가 콘 선단저항력에 미치는 영향)

  • Kim, Rae-Hyun;Lee, Woo-Jin;Yoon, Hyung-Koo;Lee, Jong-Sub
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2009.03a
    • /
    • pp.361-367
    • /
    • 2009
  • The criteria such as ASTM recommends that the zero reading process of CPT must be performed in the same temperature condition with underground in order to reduce the effect of temperature. However, this method can not consider the change of temperature occurred during penetration. In this study, ultra small size temperature sensor with 0.5mm in diameter is manufactured to estimate and compensate the effect of temperature by using FBG sensor. The continuous temperature changes are monitored during cone penetration by using FBG temperature sensor installed in cone penetrometer. The temperature compensated tip resistances show the uniform and similar distributions with depth in different with originally measured tip resistance in cohesive soil. This study verifies that the tip resistances measured by previous zero reading method are affected by the change of underground temperature, and suggests the new temperature compensation technique using by FBG temperature sensor.

  • PDF

A Survey on the Actual Conditions of Summer Working Uniforms for Contracted Foodservice Workers (위탁급식업체 종사자의 하절기 작업복 착용 실태에 관한 연구)

  • Lee, Hyo-Hyeon;Yeom, Jeong-Ha;Choi, Jeong-Wha
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.34 no.4
    • /
    • pp.553-562
    • /
    • 2010
  • This survey investigates the conditions of summer working uniforms for contracted foodservice workers. The data were obtained from 67 workers through in-depth interviews (July 2005~October 2005). The results of study are as follows: The working environment changed to menu and cooking method (air temperature $28\sim37^{\circ}C$, humidity 72~86 %RH, radiant temperature $27\sim37^{\circ}C$, air velocity 0.14~0.37m/sec). They answered that the working environment has high temperatures, humidity, excessive noise, and liability to slide. The typical accidents were burns, cuts, slide, and ligament injuries in the workplace. Work duties consisted of cooking, serving food, washing, and cleaning up leftover food. All the employees carried out multi tasks. The primary working postures and motions were standing, crouching, and lifting. The female workers usually wore underwear (panty and brassiere), upper and lower work wear, aprons, waterproof-aprons, cotton-gloves, rubber-gloves, socks, and rubber-boots. The satisfaction of the uniform was relatively low for trousers and waterproof-aprons. The answer about the fit was generally "comfortable." They answered "back," "chest," and "head" were wet with perspiration during work. The uncomfortable parts were the crotch and neck. Questions concerning their satisfaction with the material of uniforms indicated a high rate of dissatisfaction, particularly for ventilation and absorbency. In case of the colors of the working uniform, workers preferred white color for the upper part, and black color for the lower part.

Molybdeum Oxide Film Preparation by a Magnetic Null Discharge Sputtering and its Application (자기 중성방전 스퍼터링에 의한 산화몰리브덴 박막의 제작 및 그 응용)

  • Kim, Doo-Hwan;Park, Cha-Soo;Sung, Youl-Moon
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
    • /
    • v.23 no.1
    • /
    • pp.169-175
    • /
    • 2009
  • In this experiment molybdeum oxide($MoO_3$) films were prepared by a magnetic null discharge(MND) sputtering system and fundamental properties by XRD, XPS and SEM analysis were investigated. The initial and mean insulation resistance of the same with $MoO_3$ film were about 1.4[$M{\Omega}$] and 800[$k{\Omega}$] under the condition of applied voltage of 400[V]. The preferred orientation in the films changed from(100) to (210) with substrate temperature. Two XPS peaks of the $MoO_3$ photoelectron were detected at the binding energies of 228.9[eV] and 232.4[eV], while the binding energy of the O1s peak was 532.6[eV]. The substrate temperature and reactivity gives large effects to the structure and growth of the film and system is also very useful for performing the uniform reactive deposition. It can be found from the result of a $MoO_3$ film deposition that the system is very useful for performing the uniform reactive sputtering.

Free Vibration Characteristics of Rectangular Plates under Uniform Thermal Loading Part II. Experimental Modal Test (균일 열부가 하중을 받는 사각판의 자유 진동특성 연구 Part II. 고유진동 실험)

  • Jeon, Byoung-Hee;Kang, Hui-Won;Lee, Young-Shin
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.39 no.2
    • /
    • pp.106-113
    • /
    • 2011
  • This paper was conducted on experimental analysis in the free vibration analysis of rectangular plates under uniform thermal loading. Materials of three rectangular plates were aluminum, steel and stainless-steel respectively. The dimension of rectangular plates was 0.1 $\times$ 0.1 $\times$ 0.002 m. Infrared quartz lamps were used for thermal loading. The PCS(Power Control System) electric control system was applied for control and scanning vibrometer (Poly Tech) was used for acquisition of frequency response function. Applied temperature was increased from room temperature to $300^{\circ}C$ by $50^{\circ}C$. Boundary condition was free-free condition using bungee cord. Front face of rectangular plate was heated uniformly.