• 제목/요약/키워드: Hot plate test

검색결과 163건 처리시간 0.034초

Gasket 방식 판형 열교환기의 고.저온부 유량 및 압력차에 따른 압력강하 특성 (Pressure Drop of a Gasket Sealed Plate Type Heat Exchanger upon its Operating Conditions)

  • 안준;김혁주;최규성;송대석
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2009년도 하계학술발표대회 논문집
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    • pp.189-194
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    • 2009
  • In a gas engine based cogeneration system, heat is recovered from two parts, which are jacket water and exhaust gas. The heat from the jacket water is often recovered by a plate type heat exchanger and used for the room heating and/or hot water supply. Depending on the operating conditions of engine and heat recovery system, there should be imbalance in the flow rate and supply pressure between engine and heat recovery side of the heat exchanger. The imbalance cause the deformation of the plate, which affects the pressure drop characteristics. In the present study, the pressure drop inside the heat exchanger has been investigated in a 1/5 scaled test rig and compare with the experimental correlations, which are used for the design.

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Evaluation of the antinociceptive activities of natural propolis extract derived from stingless bee Trigona thoracica in mice

  • Nurul Alina Muhamad Suhaini;Mohd Faeiz Pauzi;Siti Norazlina Juhari;Noor Azlina Abu Bakar;Jee Youn Moon
    • The Korean Journal of Pain
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    • 제37권2호
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    • pp.141-150
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    • 2024
  • Background: Stingless bee propolis is a popular traditional folk medicine and has been employed since ancient times. This study aimed to evaluate the antinociceptive activities of the chemical constituents of aqueous propolis extract (APE) collected by Trigona thoracica in a nociceptive model in mice. Methods: The identification of chemical constituents of APE was performed using high-performance liquid chromatography (HPLC). Ninety-six male Swiss mice were administered APE (400 mg/kg, 1,000 mg/kg, and 2,000 mg/kg) before developing nociceptive pain models. Then, the antinociceptive properties of each APE dose were evaluated in acetic acid-induced abdominal constriction, hot plate test, and formalin-induced paw licking test. Administration of normal saline, acetylsalicylic acid (ASA, 100 mg/kg, orally), and morphine (5 mg/kg, intraperitoneally) were used for the experiments. Results: HPLC revealed that the APE from Trigona thoracica contained p-coumaric acid (R2 = 0.999) and caffeic acid (R2 = 0.998). Although all APE dosages showed inhibition of acetic acid-induced abdominal constriction, only 2,000 mg/kg was comparable to the result of ASA (68.7% vs. 73.3%, respectively). In the hot plate test, only 2,000 mg/kg of APE increased the latency time significantly compared to the control. In the formalin test, the durations of paw licking were significantly reduced at early and late phases in all APE groups with a decrease from 45.1% to 53.3%. Conclusions: APE from Trigona thoracica, containing p-coumaric acid and caffeic acid, exhibited antinociceptive effects, which supports its potential use in targeting the prevention or reversal of central and peripheral sensitization that may produce clinical pain conditions.

용접 공정 디자인에 따른 클래드강의 기계적 성질 변화 (Change of Mechanical Properties of Clad Steel According to the Welding Process Design)

  • 이정현;박재원
    • 한국생산제조학회지
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    • 제22권3호
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    • pp.372-379
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    • 2013
  • In this study, we investigated the traits of the clad metals used in hot-rolled clad steel plates. We examined the sensitization and mechanical properties of STS 316 steel plate and carbon steel (A516) under the specific circumstances of post heat treatment and whether a weld was multilayered and thick or repeated because of repairs. The test conditions were as follows. The clad steel plates were butt-welded using FCAW/SAW, and the heat treatment was conducted at $625^{\circ}C$, for 80, 160, 320, 640, or 1280 min. The change in the corrosion resistance was evaluated in these specimens. In the case of the carbon steel (A516), as the heat treatment time increased, the annealing effect caused the tensile strength to decrease. The micro- hardness gradually increased and then decreased after 640 min. The elongation and contraction of the area increased gradually. An oxalic acid etch test and EPR test on STS316, a clad metal, showed a STEP structure and no sensitization. From the test results for the multi-layered and repair welds, it could be concluded that there is no effect on the corrosion resistance of clad metals. In summary, the purpose of this study was to suggest some considerations when developing on-site techniques and evaluate the sensitization of stainless steels.

태양열 집열기 성능실험을 통한 공동주택 효율적 설치방안 연구 (A Study on the Effective Installation to the Apartment Through Solar Collector Performance Test)

  • 김미연;최병도;김형근;박진철
    • 한국태양에너지학회:학술대회논문집
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    • 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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    • pp.480-487
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    • 2012
  • The application of solar energy in residential building is general and natural in today. And application methods of solar thermal energy is divided in two kind of form, single evacuated tube and flat-plate form. Then in this study, the efficiency of single evacuated tube and flat-plate system is compared by total and effective area considering the time receiving the solar radiation between 24 hours and the specific time(10:00~15:00). As a result of the experiment, single evacuated tube and flat-plate collector's efficiency is varied by the quantity of solar radiation. And especially, the flat-plate system is more affected by outdoor temperature. Therefore the application of solar thermal system should be considered the solar radiation and outdoor temperature.

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적외선 램프 및 핫 플레이트 온도 제어를 통한 4 Bus Bar 결정질 실리콘 태양전지 솔더링 특성에 관한 연구 (A Study on the Soldering Characteristic of 4 Bus Bar Crystalline Silicon Solar Cell on Infrared Lamp and Hot Plate Temperature Control)

  • 이정진;손형진;김성현
    • Current Photovoltaic Research
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    • 제5권3호
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    • pp.83-88
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    • 2017
  • The growth of intermetallic compounds is an important factor in the reliability of solar cells. Especially, the temperature change in the soldering process greatly affects the thickness of the intermetallic compound layer. In this study, we investigated the intermetallic compound growth by Sn-diffusion in solder joints of solar cells. The thickness of the intermetallic compound layer was analyzed by IR lamp power and hot plate temperature control, and the correlation between the intermetallic compound layer and the adhesive strength was confirmed by a $90^{\circ}$ peel test. In order to investigate the growth of the intermetallic compound layer during isothermal aging, the growth of the intermetallic compound layer was analyzed at $85^{\circ}C$ and 85% for 500 h. In addition, the activation energy of Sn was calculated. The diffusion coefficient of the intermetallic compound layer was simulated and compared with experimental results to predict the long-term reliability.

헬륨 -네온 레이저자극으로 유발된 흰쥐 진통작용의 날록손 반전 (Naloxone Reversal of He-Ne Laser Stimulation Induced Analgesia in Rat)

  • 이재형;송인영;최은영
    • The Journal of Korean Physical Therapy
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    • 제8권1호
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    • pp.15-20
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    • 1996
  • The purpose of this study were to 1) determine the analgesic effect of 632.8 nm of helium-neon (He-Ne) laser stimulation on acupuncture point in rat and 2) determine the reversal of analgesic effect by naloxone injection. Eighteen Sprague-Dawley rats were devided into three groups : control (n=6) : laser (n=6), laser stimulation at $3.58\;J/cm^2$ ; and naloxone (n=6), 1 mg/kg of naloxone chloride inject into peritoneum before laser stimulation at $3.63J/cm^2$. Tail-flick latency were measured pretreat and posttreat with hot plate $(55^{\circ}C)$. Data were analyzed using one-way ANOVA and paired t-teat for tail-flick latency. No significant change was noted in the tail-flick latency in either control or naloxone groups. But significant increased in tail-flick latency in taller group. The results suggest that He-Ne laser induced analgesic effect, and endogenous opioids may be involved in He-Ne laser induced analgesia.

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태양에너지 해수담수화시스템에의 적용을 위한 판형 해수담수기의 열성능에 관한 실험적 연구 (Experimental Study on Thermal Performance of Palte-type Fresh Water Generator for applying Solar Energy Desalination System)

  • 김정배;곽희열
    • 한국태양에너지학회 논문집
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    • 제27권4호
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    • pp.35-41
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    • 2007
  • To demonstrate the desalination system, the demo-plant was scheduled to be installed. The system was planned to use solar thermal collector as heat source and PV as electricity source. For the design of the desalination demonstration system, firstly the solar thermal system would be well designed from the result between the supplied heat into the fresh water generator and the fresh water yield. The generator for demonstration system was chosen as the fresh water generator of the single stage and effect with plate-type heat exchanger using low pressure evaporation method. The test facility for the tests to reveal the relationship between the fresh water yield and the supplied heat flow rate was designed and manufactured. The maximum fresh water yield of two fresh water generators applied in this study was designed as 1.5 Ton/day. The parameters relating with the performance of fresh water generator are known as sea water inlet temperature, hot water inlet temperature, and hot water flow rate. Through the experiments, this study firstly showed detail operation characteristics of the generator and designed the solar thermal system for the demonstration system.

자연대류형 태양열 온수 급탕 시스템의 열성능 및 실증실험 (An Experimental and Field Study on Thermal Performance of Thermosyphon Solar Hot Water System)

  • 강용혁;곽희열;전홍석
    • 태양에너지
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    • 제11권1호
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    • pp.16-26
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    • 1991
  • 주거용 온수급탕에 소비되는 에너지를 절약하기 위하여 국내기후와 생활환경에 적합한 자연대류형 태양열 온수 급탕 시스템의 개발에 관한 연구이다. 비교분석을 위해 집열기와 열교환 형태에 따른 여러형태의 축열조를 제작하여 실험을 수행하였다. 또한, 열성능 분석결과를 토대로 시스템 최적화를 통한 모범도면을 작성하였고, 지역별, 기후별 실증실험을 위하여 전국7개도시(서올, 부산, 대구, 광주, 대전, 강릉, 제주)에 시범 설치하여 열성능 및 실용화 가능성을 검토하였다.

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Adjustment of Roll Gap for the Dimension Accuracy of Bar in Hot Bar Rolling Process

  • Kim, Dong-Hwan;Kim, Byung-Min;Lee, Youngseog
    • International Journal of Precision Engineering and Manufacturing
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    • 제4권1호
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    • pp.56-62
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    • 2003
  • The objective of this study is to adjust the roll gap for the dimension accuracy of bar in hot bar rolling process considering roll wear. In this study hot bar rolling processes for round and oval passes have been investigated. In order to predict the roll wear, the wear model is reformulated as an incremental form and then wear depth of roll is calculated at each deformation step on contact area using the results of finite element analysis, such as relative sliding velocity and normal pressure at contact area. Archard's wear model was applied to predict the roll wear. To know the effects of thermal softening of DCI (Ductile Cast Iron) roll material according to operating conditions, high temperature micro hardness test is executed and a new wear model has been proposed by considering the thermal softening of DCI roll expressed in terms of the main tempering curve. The new technique developed in this study for adjusting roll gap can give more systematically and economically feasible means to improve the dimension accuracy of bar with full usefulness and generality.

Neuropharmacological study of hot water extract of the seeds of Vernonia anthelmintica Kuntze

  • Rahman, Mahbubur;Choudhuri, M Shahabuddin Kabir;Khan, Mahmud Tareq Hassan;Jabbar, Shaila;Alamgir, Mahiuddin
    • Advances in Traditional Medicine
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    • 제6권1호
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    • pp.34-38
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    • 2006
  • The hot water extract of the seeds of Vernonia anthelmintica Kuntze (Compositae) in a dose of 10 ml/kg body weight of mice, showed significant analgesic activity on the hot plate analgesic method throughout the 4 h experimental period. The hole cross scores and the climbing out scores are of lower than the control animals. The hot water extract reduced the defecation in hole board study and significantly reduces the exploratory ambulation and head dipping behaviour. The seed also showed significant depressant activity on the exploratory ambulation of the open field scores. The drug decreased the spontaneous locomotion activity on brick-chip displacement method up to 45 min and also showed the ability to lessen the amphetamine induced hyperactivity up to 20 min. But it didn't show any effect on pentobarbital induced sleeping time test. The extract reduced gastrointestinal motility.