• Title/Summary/Keyword: boiling effect

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Thermal stabilityof fluorine doped silicon oxide films

  • Lee, Seog-Heong;Yoo, Jae-Yoon;Park, Jong-Wan
    • Journal of Korean Vacuum Science & Technology
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    • v.2 no.1
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    • pp.25-31
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    • 1998
  • The reliability of fluorine doped silicon oxide (SiOF) films for intermetal dielectrics in multilevel interconnections of ultra-large scale integrated circuits (ULSIs) is investigated. SiOF films were deposited by electron cyclotron resonance plasma-enhanced chemical vapor deposition (ECRPECVD) using H-free source gases, i.e., SiF4 and O2. The effect of post plasma treatment on the moisture absorption and dielectric properties of SiOF films was carried out I terms of air exposure time, The reliability test of Cu/TiN/SiOF/Fi specimen was carried out in terms of temperature by rapid thermal annealing (RTA) in N2 ambient. After O2 plasma treatment,, no appreciable peak directly related to moisture absorption was detected. The capacitance-voltage (C-V) characteristics of the O2 plasma treated SiOF film showed that the film remained to hold the sound dielectric properties even after boiling treatment. The Cu/TiN/SiOF/Si system was found to be reliable up to $600^{\circ}C$.

NaOCl produced by electrolysis of seawater using BDD electrode (BDD전극을 이용한 해수에서의 NaOCl 생성)

  • Hong, Kyeong-Mi;Park, Soo-Gil;Okajima, Takeyoshi;Ohsaka, Takeo;Fujishima, Akira
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.373-374
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    • 2005
  • NaOCl (Sodium hydrochlorite) have similar smell of chloride and solution of straw color. And boiling point is $110^{\circ}C$, specific gravity is 1.0(50g/l)/1.1(100g/l), Value of pH is 12. NaOCl playa role as bleach, a oxidizer, a germicide, a decolorant, a deodorant, treatment of water supply and drainage, food addition agent because strong oxidation, bleaching, sterilization effect is had. When NaOCl is produced in electrolysis of seawater, this system is composed of injection system by directly electrolysis of salt water on the spot and sodium hydrochlorite generate a safe low concentration(0.4~0.8 %).

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Additional power conservation in 200W power plant with the application of high thermal profiled cooling liquid & improved deep learning based maximum power point tracking algorithm

  • Raj G. Chauhan;Saurabh K. Rajput;Himmat Singh
    • Advances in Energy Research
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    • v.8 no.3
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    • pp.185-202
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    • 2022
  • This research work focuses to design and simulate a 200W solar power system with electrical power conservation scheme as well as thermal power conservation modeling to improve power extraction from solar power plant. Many researchers have been already designed and developed different methods to extract maximum power while there were very researches are available on improving solar power thermally and mechanically. Thermal parameters are also important while discussing about maximizing power extraction of any power plant. A specific type of coolant which have very high boiling point is proposed to be use at the bottom surface of solar panel to reduce the temperature of panel in summer. A comparison between different maximum power point tracking (MPPT) technique and proposed MPPT technique is performed. Using this proposed Thermo-electrical MPPT (TE-MPPT) with Deep Learning Algorithm model 40% power is conserved as compared to traditional solar power system models.

Transient behavior of cryogenic thermosiphon working with R14 and nitrogen mixture (R14와 질소 혼합유체를 사용하는 극저온 열사이펀의 과도상태 거동)

  • Lee, Ji-Sung;Jeong, Sang-Kwon
    • Progress in Superconductivity and Cryogenics
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    • v.12 no.1
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    • pp.66-70
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    • 2010
  • The operational temperature range of thermosiphon is generally limited from the critical point to the triple point of the working fluid to maintain two-phase state. Thermosiphon with mixed working fluid has a potential to widen the operational temperature range. In this study, the physical behavior of mixed working fluid during the transient operation of thermosiphon was analyzed with temperature-mole fraction diagram. The condenser and the evaporator temperature variations were explained by the dew line and the bubble line of the mixture. It is encouraging that the thermosiphon operation commences early with larger fraction of high boiling point component, but the temperature gap between the condenser and the evaporator due to the separation of two components has a negative effect on the officient cool down process.

EFFECTS OF WATERY VAPOR CONCENTRATION ON DROPLET EVAPORATION IN HOT ENVIRONMENT

  • Lee, M.J.;Kim, Y.W.;Ha, J.Y.;Chung, S.S.
    • International Journal of Automotive Technology
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    • v.2 no.3
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    • pp.109-115
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    • 2001
  • A study has been conducted to clarify the effect of watery vapor concentration in hot ambient on droplet evaporation. Droplets of water, ethanol, n-hexadecaneand n-heptane were used in this experimental study. Ambient conditions are fixed at 470 K in temperature, 0.1 MPa in pressure and 2 m/s in velocity of ambient air. Watery vapor concentration was changed 0%~40% by 10% by add water to air. To obtain the time histories of droplet diameter after exposed in ambient, a suspended droplet in hot and humid ambient stream was synchronized with a back flash light, and enlarged droplet images were taken by a CCD camera. The evaporation rate constant of water droplet decreases slightly with the vapor concentration because diffusion velocity reduction of droplet vapor occurs on the surface. The values of ethanol and n-heptane droplet actively increase by effect that water from condensation of vapor flows into the droplet. The evaporation rate constant of n-hexadecane which has higher boiling point than water increases within around 30% of the concentration.

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The Effect of Sodium dithionite in Dyeing with Indigo Pulverata Levis (청대 염색에서 sodium dithionite의 영향)

  • Cho, Kyung-Rae
    • Textile Coloration and Finishing
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    • v.27 no.2
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    • pp.155-163
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    • 2015
  • In dyeing cotton fabric with the Indigo Pulverata Levis, this research examined the effect of the sodium dithionite($Na_2S_2O_4$). For the separation of the Indigo-calcium hydroxide complex in the alkaline solution of the Indigo Pulverata Levis, the reduction with the $Na_2S_2O_4$ at $25^{\circ}C$ was more effective than the solution boiling. The concentration of Indigo in the cotton fabric increased with the increase of Indigo Pulverata Levis, but the concentration of indirubin did not increase particularly. The optimum temperature for the reduction was $60^{\circ}C$, and K/S value of dyed fabric decreased at over $60^{\circ}C$. The concentration of indigo and indirubin in the cotton fabric decreased as $Na_2S_2O_4$ concentration increased. In treating cotton fabric dyed with the Indigo Pulverata Levis by the $Na_2S_2O_4$, the concentration of indirubin decreased and the surface color of dyed cotton changed from purple blue to blue while the treatment temperature was getting higher.

Effect of Carbon Content on the Shape of WC Grains during Liquid Phase Sintering of WC-Co Hard Metals (WC-Co 초경합금의 액상소결시 WC 입자형상에 미치는 탄소량의 영향)

  • 한석희;박종구;허무영
    • Journal of Powder Materials
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    • v.6 no.4
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    • pp.307-313
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    • 1999
  • The effect of carbon content on the shape of WC grains dispersed in the Co-rich matrix during liquid phase sintering of WC-35%Co hard metals has been determined. The shape of WC grains was observed using SEM stereography after removing cobalt matrix with boiling hydrochloric acid solution. The WC grains changed from hexagonal to trigonal prism as the carbon content increased in the two-phase region of(WC + $\beta$ - Co), while the morphology of WC grains changed from trigonal to hexagonal shape as the carbon content decreased. The morphology of WC grains changes reversibly along with carbon loss or carbon pick-up. Morphology change of WC grains is attributed to crystal structure of WC, which has an asymmetric array of carbon atoms. There are two types of prismatic planes having different numbers of broken W-C bonds in WC grains. It is scrutinized that as the carbon content increases, the high energy prism planes grow fast and the crystals change from hexagonal to trigonal shape. On the other hand, when the carbon content decreases, the high energy prism planes are dissolved accompanying split of (100) plane into (101) and (101) planes.

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A Study on the Drag Reduction by Shear-thinning Fluid in Turbulent Flow Fields (난류유동장에서 Shear - thinning 유체에 의한 마찰저항 감소에 관한 연구)

  • 차경옥;김재근;오율권
    • Journal of Advanced Marine Engineering and Technology
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    • v.21 no.2
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    • pp.126-135
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    • 1997
  • Drag reduction in polymer solutions is the phenomenon where by extremely dilute solutions of high molecular weight polymers exhibit frictional resistance to flow much lower than the pure solvent. This effect, largely unexplained as yet, has attracted the attention of polymer scientists and fluid flow specialists. Although applications are beginning to appear, the principle interest to data has been in attempting to relate the effect to the fluid mechanics of turbulent flow. Drag reduction in two phase flow can be applied to the transport of crude oil, phase change system such as chemical reactor, and pool and boiling flow. But the research on drag reduction in two phase flow is not intensively investigated. Therefore, experimental investigations have been carried out to analyze the drag reduction produced by polymer addition in the single phase and two phase flow system. The objectives of the proposed investigation are primarily in identifying and developing high performance polymer additives for fluid transportations with the benefits of turbulent drag. Also we want to is to evaluate the drag reduction in horizontal flow by measuring pressure drop and mean velocity. Experimental results show higher drag reduction using co - polymer(A611P) then using polyacrylamide (PAAM) and faster degradation using PAAM than using A611P under the same superficial velocity.

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Extingushiment by the Colling Effect of the Fuel Surface with Pool Fires (Pool 화재에서의 표면 냉각에 의한 소화)

  • 한용식;김명배;신현동
    • Fire Science and Engineering
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    • v.11 no.4
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    • pp.15-23
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    • 1997
  • A series of measurements and visualization to investigate the extingushiment of water sprays with pool fires is presented. Fire source is a small-scale pool burner with methanol, ethanol and gasoline. Measurements of temperature, O2, CO2, and CO concentrations along the plume centerline are carried out to observe pool structures without water sprays. Visualization by the Ar-ion laser sheet flow pattern of droplets of the sprays above the pool fires. It is observed than in the case of methanol and ethanol, water sprays continuously penetrate into the center of fuel surfaces. The gasoline pool fire allows intermittent penetration of water sprays because of pulsating characteristics of the gasoline flame. To evaluate the cooling effect of the fuel surface by the sprays, the temperature was measured at the fuel surface. As soon as the mists reach the fuel surface of methanol and ethanol, the temperatures of the fuel surface decrease rapidly below the boiling point, and then the fires are extinguished. Due to the application of mist upon the gasoline fire, though the fuel temperature decrease abruptly at the time of the injection, such a repid decrease do not continue till the extinction point.

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Effect of Ganoderma lueidum Water- Extracted Solution on Fat Contents in Plasma, Liver and Adipose, and Feccal Steroids of Fatted Rats Induced by High Fat Dietary (영지의 열수 추출액이 고지방식이에 의한 흰쥐의 혈장, 간 및 지방조직의 지질함량과 분변 Steroids에 미치는 영향)

  • Seong, Tae-Su;Son, Gyu-Mok;Bae, Man-Jong
    • The Korean Journal of Food And Nutrition
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    • v.9 no.1
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    • pp.76-84
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    • 1996
  • This study was carried out to evaluate the effect of Ganoderma lueuidum (GL) water extract on fat accumulation in the fatted rats Induced by the oral high fat administration for six weeks. Total cholesterol, neutral fat and epididymal fat pad of GL groups were lower than the control group. On the other hand, high density lipoprotein(HDL) -cholesterol was somewhat higher in GL than In the control group. In addition, the same result as the above case was obtained when examining adipose for liver and epididymal fat components. During the feeding experiment, level of low density lipoprotein(LDL) and very low density lipoprotein (VLDL) increased while HDL was decreased in the control group as compared with normal group. The decree of LDL and VLDL was decreased, but HDL was increased in GL group as compared with the control group. Experiment group showed the Increased excretion as compared with the control group, in the excretion. Based on the above results, It was shown that it is possible to improve fat accumulation induced by high fat dietary through using the oral administration of Ganoderma lueidum boiling extract solutions.

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