• Title/Summary/Keyword: heating temperature and time

Search Result 1,375, Processing Time 0.027 seconds

Measurement of properties of laser-produced plasmas (레이저플라즈마의 제특성의 계측)

  • 강형부
    • 전기의세계
    • /
    • v.29 no.2
    • /
    • pp.118-128
    • /
    • 1980
  • The properties of plasmas produced by high power glass laser were investigated with various methods of diagnostics. Electron temperature was estimated by measurement of soft X-ray, and ion temperature was estimated by measurement of the time-of-flight of ion. The measurement of incident and reflected laser light, and Schlieren and shadowgragh methods were also used. No influence of laser pulse duration on the temperature was observed in the case of durations 2, 4 and 10 nsecs. The effective heating of plasma occurred in about 2 nsec of beginning of incident laser pulse. The experimental results for fast rising laser pulse were discussed and the influence of resetime of laser pulse on the heating of plasma was described. Neutrons produced by irradiating laser beam to solid deuterium target were detected.

  • PDF

Thermal Energy Characteristics and Simulation Model Development for Greenhouse Heating System Using Solar Energy (태양에너지를 이용한 그린하우스 난방시스템의 열특성과 시뮬레이션 모델개발)

  • Ro, J.G.;Song, H.K.
    • Journal of the Korean Solar Energy Society
    • /
    • v.21 no.2
    • /
    • pp.27-34
    • /
    • 2001
  • The greenhouse heating system using solar energy has been realized in the protective agriculture in this study in order to analyse the thermal energy characteristics of the system the effects of ambient air temperature, solar radiation, relative humidities and water content of ambient air on the greenhouse air temperature were investigated through computer simulation experimental analysis for validation of the simulation. The results from this study are summarized as follows: 1) The expected values of inside air temperature for the system solar energy were very much close to the experimental values. 2) In the system using solar energy, the expected values of daytime surface temperature of soil by computer simulation were very much similar to the measured values, but those of nighttime were higher than the measured value by almost $2.5^{\circ}C$. 3) Heat loss of daytime was found to be larger than that of night time as much as 2.0 to 4.2 times for the system using solar energy. 4) In the system using solar energy. while the ambient air temperature varied between $-7^{\circ}C$ and $-3.8^{\circ}C$, the temperature of the inside air was maintained between $0^{\circ}C$ and $22^{\circ}C$. 5) At the minimum ambient temperature of $-7^{\circ}C$, the temperature of the inside air was $0^{\circ}C$.

  • PDF

A Study on the Characteristics of Inversion Layer Observed at Kimhae (김해에서 관측한 접지역전층의 특성에 관한 연구)

  • 박종길;원경미
    • Journal of Environmental Science International
    • /
    • v.3 no.4
    • /
    • pp.305-315
    • /
    • 1994
  • The field observation was carried out to investigate the characteristics of surface inversion layer at Kimhae using the feild observed date and upper layer meteorological data during 4-5 February 1993. The results of the study can be summarized as follows : The maximum height of surface inversion layer observed at Kimhae is 193m and the height of upper level inversion layer ranges from 2nm to 300m. The surface weather elements was influenced the formation of surface inversion layer. According to the pasquill stability and time variation of temperature with height, both the surface heating from insolation and the disturbance of upper level of inversion layer was influenced the disappearance of inversion layer. And the stability of surface temperature inversion layer generally belongs to the class of F, that of upper level temperature inversion layer commonly to the class of E.

  • PDF

Study on the Improvement of Dyeability of Commercial Indigo Leaf Powder for the Purpose of Utilizing It in Indigo Dyeing (시판 쪽잎 분말의 쪽 염료에의 활용을 위한 염색성 향상 연구)

  • Yoo, Wansong;Ahn, Cheunsoon;Narantuya, Lkhagva;Li, Longchun
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.38 no.4
    • /
    • pp.540-556
    • /
    • 2014
  • This research investigated the effective conditions to dye cotton with commercial indigo leaf powder. We tested dyeing conditions of: pH of dyebath (6.5, 9-12), heating ($20^{\circ}C$, $50^{\circ}C$, $70^{\circ}C$, $90^{\circ}C$), ageing (0, 0.5, 1, 4, 24 hours), reduction time (0, 30, 60 min), and dyeing temperature ($2^{\circ}C$, $10^{\circ}C$, $20^{\circ}C$, $50^{\circ}C$, $70^{\circ}C$, $80^{\circ}C$), dyeing was conducted for 20 minutes. The highest K/S value was obtained when cotton was dyed using pH 11 dyebath, heated at $50^{\circ}C$ for 30 minutes, aged for 24 hours at room temperature ($20^{\circ}C$), reduction carried out for 30 minutes, and dyed at $50^{\circ}C$. It is proposed that the K/S value is primarily influenced by the dyebath pH and dyeing temperature, followed by the presence or absence of ageing time and reduction time. The color of cotton with high K/S values was B type by Munsell hue value, which was similar to the color obtained in previous studies by freshly made indigo leaf powder and indigo leaf juice. The results indicate that the dyeing conditions established in this research are suitable to maximize the dyeability of commercial indigo leaf powder and that the indigo leaf powder can be used as a substitute for fresh indigo leaf juice.

Physiological Responses and Subjective Sensation of Human Body Wearing OnMapsi in Heating Environment (난방환경에서 온(溫)맵시 착용에 따른 생리적 반응 및 주관적 감각)

  • Na, Young-Joo;Lee, Ji-Yun
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.35 no.1
    • /
    • pp.1-12
    • /
    • 2011
  • This study tests the performance of the recommended winter dress OnMapsi for an office worker through the analysis of skin temperature changes according to the heating environment. We tested and compared the effects of with/without undergarments for 4 male subjects in an artificial-climate chamber with two air temperatures of $19^{\circ}C$ and $22^{\circ}C$, $50{\pm}10%$ R.H. During the 60 minute experiment that simulated office work, the subjective feelings (that included thermal, humidity and comfort sensation, and skin temperature) were measured at equal intervals. The results show that the forehead and chest skin temperatures were not affected by air temperature or clothing type, while the hand and foot skin temperatures were affected at $0.3-0.9^{\circ}C$ depending on clothing type and $1.9-2.2^{\circ}C$ depending on air temperature. The mean skin temperature was decreased by the experimental time pass more with regular formal wear than with OnMapsi. The second experiment located the ambient temperature in which subjects wearing OnMapsi show equal skin temperaturesto those without undergarments at $22^{\circ}C$. Therefore it is possible to decrease heating temperatures to $18-21^{\circ}C$ in the office for winter OnMapsi wear that produces a skin temperature and thermal sensation that is the same as those at $22^{\circ}C$.

Study on Deterioration of Domestic Edible Oils Upon Heating at High Temperatures (시판식용유(市販食用油)의 고온연속가열(高溫連續加熱)에 따르는 경시적(經時的) 변화(變化)에 관(關)한 연구(硏究))

  • Oh, Young-Bok;Kim, Kwang-Ho
    • Journal of Nutrition and Health
    • /
    • v.11 no.3
    • /
    • pp.25-30
    • /
    • 1978
  • A study was planned to evaluate the influence of continual heating at $150{\pm}5^{\circ}C$ and $170{\pm}5^{\circ}C$ respectively upon edible oils for frying the several food. Two kinds of domestic edible oils (Sample A and B) were collected by random sampling from market and in order to estimate deterioration degrees at both temperatures previously mentioned, thiobarbituric acid (TBA) value, acid value (AV), peroxide value (POV) and carbonyl value (CV) were measured at intervals due to its optical density. Those values were examined and compared according to the temperatures and times, and it was concluded as follows: 1) TBA value was rapidly increased until 24 hours in both temperatures and after 1 day its value have shown a slower increase as compared with initial rapid reaction. 2) Acid value and peroxide value of both oils (A & B) used for frying were increased continuously during heating and the changes in these values were dependent on the thermal oxidation, and moreover at low temperature $(150{\pm}5^{\circ}C)$ these values were found to be increased more readily than at high temperature $(170{\pm}5^{\circ}C)$. 3) Carbonyl value of both sample A and B show almost the same increasing rate at either $150{\pm}5^{\circ}C$ or $170{\pm}5^{\circ}C$ in proportion to the heating time. 4) It was found that there were differences between the chemical changes caused by heating sample A and B at high and low temperature.

  • PDF

Numerical Analysis of Laboratory Heating Experiment on Granite Specimen (화강암의 실내 가열실험에 대한 수치해석적 검토)

  • Dong-Joon, Youn;Changlun, Sun;Li, Zhuang
    • Tunnel and Underground Space
    • /
    • v.32 no.6
    • /
    • pp.558-567
    • /
    • 2022
  • The evolution of temperature and thermal stress in a granite specimen is studied via heating experiment in the context of a high-level radioactive waste repository. A heating condition based on the decay-induced heat is applied to a cubic granite specimen to measure the temperature and stress distributions and their evolution over time. The temperature increases quickly due to heat conduction along the heated surfaces, but a significant amount of thermal energy is also lost through other surfaces due to air convection and conduction into the loading machine. A three-dimensional finite element-based model is used to numerically reproduce the experiment, and the thermo-mechanical coupling behavior and modeling conditions are validated with the comparison to the experimental results. The most crucial factors influencing the heating experiment are analyzed and summarized in this paper for future works.

Development of Pipe-Inserted Cast Die for Press Forming Process Using Ansys and LabView (Ansys와 LabView를 이용한 프레스 성형용 파이프 인서트 주조금형 개발)

  • Lho, Tae-Jung;Choi, Hyeon-Chang
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.10 no.12
    • /
    • pp.3559-3566
    • /
    • 2009
  • Heating and cooling plate are separately used for heating and cooling cast dies for footwear parts. However, this has a disadvantage that it takes a long time to manufacture footwear parts etc.. In the present study, the pipe-inserted cast die for press forming process was proposed to substitute heating and cooling plate. The temperature distribution on the pipe-inserted cast die was analyzed by numerical work using a FEM. And its temperature was measured by LabView. A manufacturing by the pipe-inserted cast die for press forming process was effectively verified, especially in a productivity.

Fabrication and Property Evaluation of Cu-Mn Compacts for Sputtering Target Application by a Pulsed Current Activated Sintering Method (펄스전류활성소결법을 이용한 스퍼터링 타겟용 Cu-Mn 소결체 제조 및 특성평가)

  • Jang, Jun-Ho;Oh, Ik-Hyun;Lim, Jae-Won;Park, Hyun-Kuk
    • Journal of Powder Materials
    • /
    • v.23 no.1
    • /
    • pp.1-7
    • /
    • 2016
  • Cu-Mn compacts are fabricated by the pulsed current activated sintering method (PCAS) for sputtering target application. For fabricating the compacts, optimized sintering conditions such as the temperature, pulse ratio, pressure, and heating rate are controlled during the sintering process. The final sintering temperature and heating rate required to fabricate the target materials having high density are $700^{\circ}C$ and $80^{\circ}C/min$, respectively. The heating directly progresses up to $700^{\circ}C$ with a 3 min holding time. The sputtering target materials having high relative density of 100% are fabricated by employing a uniaxial pressure of 60 MPa and a sintering temperature of $700^{\circ}C$ without any significant change in the grain size. Also, the shrinkage displacement of the Cu-Mn target materials considerably increases with an increase in the pressure at sintering temperatures up to $700^{\circ}C$.

Numerical study of double diffusive convection due to lateral heating in a rotating annulus (회전하는 환형용기내의 옆면 가열에 의한 이중확산대류에 관한 수치해석)

  • Gang, Sin-Hyeong;Lee, Gyo-Seung;Lee, Jin-Ho
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.21 no.11
    • /
    • pp.1422-1436
    • /
    • 1997
  • Numerical investigations were conducted to study the convective phenomena of an initially stably stratified salt water solution with lateral heating in a uniformly rotating annulus. The method of investigation is the finite difference analysis of the basic conservation equation for an axisymmetric, unsteady, double-diffusive convection and calculation is made for R $a_{\eta}$=2*10$^{5}$ and Ta=10$^{7}$ ~ 2.5*10$^{8}$ . Formation of layered flow structure, merging process of layers, the corresponding temperature and concentration distributions, Nu variation with time are examined. Numerical results show that in each layer, the temperature profile looks 'S'-shaped and the concentration profile is uniform due to the convective mixing. At the interface between adjacent layers, the temperature changes smoothly but the concentration changes rapidly. As the effect of the rotation increases, the generation of rolls at hot wall, the formation and merging of layers are delayed. The average Nu shows the trend of conduction heat transferees the effect of the rotation increases.n increases.