• Title/Summary/Keyword: Heating Characteristics

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Study on the Hydration and Strength Properties of Fly-ash Modified Cement Paste and Mortar Using a CSA and Pulp Ash (CSA 및 제지애쉬를 혼합재료 사용한 플라이애쉬 시멘트 모르타르의 수화 및 강도 특성에 관한 연구)

  • Song, Tae-Hyeob;Lee, Sea-Hyun;So, Chee-Ho
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.1 no.1
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    • pp.81-88
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    • 2005
  • The fly ash has been widely used in the latest to complement the performance and economical efficiency of the concrete which uses only a normal portland cement, the pulp ash gained through the incineration of paper sludge is possible to be used as the material of concrete because it contains the properties similar to the previous fly ash in ingredients and physical characteristics. Therefore, this research has tested physical characteristics by replacing 20% of fly ash used with the paper ash to solve the problem which lowers the early strength caused when the fly ash was used. As a result, it showed that the fluidity becomes lower and the compressive strength becomes increased by using paper ash. In addition, after mixing the paper ash with the fly ash, it showed that time and heating amount of the 2nd peak of the minor heat of hydration affecting the revelation of strength was equivalent to the combination for normal portland cement, and also indicated that the compressive strength for 3 days is superior to the combination of the fly ash. Therefore, if the paper ash having a regular fineness is used, it was effective in improving the early strength of concrete used the fly ash.

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Characteristics of Alkaline and Acid Phosphatase in Echinostoma hortense (호르텐스극구흡충에서 Alkaline Phosphatase 및 Acid Phosphatase의 특성)

  • 양용석;김인식;임지애;강성구;박주연
    • Biomedical Science Letters
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    • v.5 no.1
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    • pp.119-129
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    • 1999
  • This study was aimed to investigate the enzyme-histochemical localization and characteristics of alkaline and acid phosphatase extracted from adult of Echinostoma hortense. Using the Gomori calcium stain and the Gomori lead nitrate satin method, we found that the alkaline and acid phosphatases were localized mostly in the intestine, vitellaria and pharynx of Echinostoma hortense. The three isozymes of alkaline phosphatase and two isozymes of acid phosphatase were separated from Echinostoma hortense by electrophoresis. The isozymes of alkaline phosphatase were 145.9, 207.5, 220.8 kDa and the isozymes of acid phosphatase were 179.5 and 209.4 kDa. The activity of alkaline phosphatase was denatured completely after heating at 9$0^{\circ}C$ for 12 seconds. The optimum pH and temperature for activity of alkaline phosphatase were about pH 9 and 4$0^{\circ}C$, while the optimum pH for activity of acid phosphatase was about pH 5. The maximum activity of alkaline phosphatase was at 189 unit, but maximum activity of acid phosphatase was at 71 unit As the result from above, we observed that alkaline and acid phosphatases funtion mainly in the alimentary tract and vitellaria. Echinostoma hortense performs the parasitism in the intestine of host by using proper isozyme of phosphatase.

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Drying Characteristics of High Moisture Low Rank Coal using a Steam Fluidized-bed Dryer (스팀 유동층 건조기를 이용한 고수분 저등급 석탄의 건조 특성)

  • Kim, Gi Yeong;Rhee, Young-Woo;Park, Jae Hyeok;Shun, Dowon;Bae, Dal-Hee;Shin, Jong-Seon;Ryu, Ho-Jung;Park, Jaehyeon
    • Clean Technology
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    • v.20 no.3
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    • pp.321-329
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    • 2014
  • In this study, Indonesia low rank coal, which has moisture content of around 26%, is dried less than 5% by using a laboratory-scale (batch type) steam fluidized-bed dryer in order to produce the low-moisture, high rank coal. Normally, CCS (carbon capture and storage) process discharges $CO_2$ and steam mixture gas around $100-150^{\circ}C$ of temperature after regeneration reactor. The final purpose of this research is to dry low rank coal by using the outlet gas of CCS process. At this stage, steam is used as heat source for drying through the heat exchanger and $CO_2$ is used as fluidizing gas to the dryer. The experimental variables were the steam flow rate ranging from 0.3 to 1.1 kg/hr, steam temperature ranging from 100 to $130^{\circ}C$, and bed height ranging from 9 to 25 cm. The characteristics of the coal, before and after drying, were analyzed by a proximate analysis, the heating value analysis and particle size analysis. In summary, the drying rate of low rank coal was increased as steam flow rate and steam temperature increased and increased as bed height decreased.

The Study on the improvement of vehicle fuel economy test method according to the characteristics of test fuel (시험용 연료 특성에 따른 자동차 연비측정 방법 개선에 관한 연구)

  • Lee, Minho;Kim, Jeonghwan
    • Journal of Energy Engineering
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    • v.23 no.4
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    • pp.9-18
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    • 2014
  • These test methods, the current domestic vehicles fuel economy calculation method is tested on a dynamometer for vehicles after you have installed the vehicle, given the test mode(FTP-75 & HWFET mode, etc.) are measured by vehicle emissions and fuel economy by seeking to have the results approach, the carbon balance method. At this point, using the carbon balance method is a test method was developed seeking fuel for a standard fuel properties, where the value of the constant and saved test was measured in THC, CO, $CO_2$ has a value calculation. Therefore, use fuel which is changed every time you test the fuel properties characteristics are not considered exactly. In this study, using the carbon balance method and fluid flow rate of the fuel used in the actual test is measured by comparing the results with the flow measurement methods, properties of the fuel used for the test attribute to study ways that can be considered, taking into account the physical attributes of a more diverse fuel line and fuel economy improved measurement methods that can be reviewed.

The Comparative Study on the Characteristics of Thermoacoustic Laser According to Shapes of Resonance Tube (공명 튜브의 기하학적 형상에 따른 열음향 레이저의 특성 비교 연구)

  • Kim, Nam-Jin;An, Eoung-Jin;Oh, Won-Jong;Oh, Seung-Jin;Chun, Wongee
    • Journal of Energy Engineering
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    • v.21 no.2
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    • pp.133-137
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    • 2012
  • Among various clean energy technologies, the solar energy technology has been widely used in various fields such as photovoltaic power generation and solar water/space heating. These days, special attention is drawn on its conversion into acoustic energy along with waste heat as a means to promote clean energy utilization. This work was carried out to investigate the possibility of converting solar energy into acoustic waves, especially, its performance characteristics for a single resonance tube (20.2 mm in ID). Variations are made for the stack length and its position as well as power supply. For a resonance tube of 200mm, an average sound pressure of 114.5 dB was measured with a stack length of 25.6mm at 5cm from the closed end. When the power supply was increased to 35W, an average sound pressure of 117.29 dB was detected with a frequency of 500Hz. There was an increase in frequency, 630 Hz (115.7dB), with a shorter resonance tube of 150mm.

The Quality Characteristics of Beef Sausage with the Addition of Gynura procumbens (명월초 가루를 첨가한 우육 소시지의 최적화 연구)

  • Park, Young Il;Jeong, Hee Sun;Joo, Nami
    • Korean journal of food and cookery science
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    • v.31 no.4
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    • pp.395-404
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    • 2015
  • The aims of this study were to determine the optimal mixing condition for two different amounts of Gynura procumbens powder and olive oil for the preparation of beef sausage. The experiments were designed according to the central composite design of response surface methodology, which showed 10 experimental points including two replicates of Gynura procumbens powder and olive oil. The physicochemical and mechanical characteristics as well as the sensory properties were measured, and these values were applied to the mathematical optimization models. The results of the physiochemical and mechanical analysis of each sample, including chewiness, cohesiveness, color a, color b, moisture content, salinity and heating loss showed significant differences. The sensory measurements were significantly different in color, flavor, tenderness, texture and overall quality. The optimum formulation, which was calculated using the numerical and graphical method, was determined to be 2.1 g Gynura procumbens powder and 7.06 g of olive oil.

Esterase Production and Culture Characteristics of Bacteria Isolated from Acid Hydrolysed Soybean Protein (산분해 대두 단백질로부터 분리된 Esterase 생성균의 생육 및 효소생성 특성)

  • Oh, Nam-Soon
    • Applied Biological Chemistry
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    • v.40 no.6
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    • pp.484-489
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    • 1997
  • The characteristics of growth and esterase activity of bacterial strains isolated from acid hydrolysed soybean protein were examined. All the isolated strains having decomposition activity of p-hydroxybenzoic acid butyl ester and esterase producing activity were identified as Bacillus sp. by morphological and biochemical methods. The specific growth rates, esterase activities and p-hydroxybenzoic acid butyl ester decomposition activities of isolated strains were $0.844{\sim}1.213\;h^{-1}$, $21{\sim}222\;mU/ml$ and $5.4{\sim}8.1\;mU/ml$, respectively. In the fermentation of Bacillus sp. KB8 strain which had the highest esterase producing activity, growth, extracellular excretion and intracellular synthesis of esterase were inhibited by adding NaCl in the culture broth. Esterase producing activity gradually increased after late exponential growth phase, until maximum value of 420 mU/ml reached after 64 hours culture period. Esterase of Bacillus sp. KB8 strain was stable up to $50^{\circ}C$ for 30 minutes, but was inactivated by heating for 30 minutes at $70^{\circ}C$. The enzyme activity exponentially decreased during the incubation time at the temperatures of $60^{\circ}C$ and $65^{\circ}C$.

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The Study on the Combustion and Ash Deposition Characteristics of Ash Free Coal and Residue Coal in a Drop Tube Furnace (DTF를 이용한 무회분 석탄과 잔탄의 연소 및 회 점착 특성에 관한 연구)

  • Moon, Byeung Ho;Kim, Jin Ho;Sh, Lkhagvadorj;Kim, Gyu Bo;Jeon, Chung Hwan
    • Journal of Energy Engineering
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    • v.24 no.4
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    • pp.89-96
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    • 2015
  • Recently, much research has been put into finding the causes and solutions of slagging/fouling problems that occur at the end of the boiler. This slagging/fouling, caused by low-rank coal's ash, disturbs the thermal power and greatly reduces efficiency. In environmental aspects, such as NOx pollution, governments have been implementing restrictions on the quantity of emission gases that can be released into the atmosphere. To solve these problems, research on Ash Free Coal (AFC), which eliminates ash from low-rank coal, is in progress. AFC has advantages over similar high-rank coals because it increases the heating value of the low grade coal, reduces the contaminants that are emitted, and decreases slagging/fouling problems. In this study, using a DTF, the changes of NOx emissions, unburned carbon, and the characteristics of ash deposition were identified. KCH raw coal, AFC extracted from KCH, residue coal, Glencore, and Mixed Coal (Glencore 85wt% and residue coal 15wt%) were studied. Results showed that AFC had a significantly lower emission of NOx compared to that of the raw coal and residue coal. Also, the residue coal showed a higher reactivity compared to raw coal. And finally, In the case of the residue coal and mixed coal, they showed a lower ash deposition than that of low-rank coal.

Effects of Non-combustible moxibustion on Thermography of Healthy Human Beings (비연소식(非燃燒式) 구법(灸法) 재료(材料)를 이용한 온열자극(溫熱刺戟)이 체열방사(體熱放射)에 미치는 효과)

  • Choi, Won-Jong;Kim, Jae-Hyo;Kim, Kyung-Sik;Sohn, In-Chul
    • Korean Journal of Acupuncture
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    • v.21 no.3
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    • pp.21-38
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    • 2004
  • Objectives : Moxibustion has been become very useful tool to prevent and treat various diseases with acupuncture in oriental medicine. Expecially, moxibustion combining the heat stimulation and chemical stimulation of Artemisiae Argyi has a non-invasive characteristics comparing to the other therapeutic tools. However, because the moxibustion makes the patient's skin be burn by the combustible feature of moxibustion, most of people have been scared of being scald. Methods : In this study, we have developed new non-combustible moxibustion tools in collaboration with company (Hana Medical, co. and ICURE, co.) and tested the efficacy through effects of moxibustion of Cheon-chu $(ST_{25})$ on the abdominal thermography of health subject. The non-combustible moxibustion has main characteristics of controlled heating to inhibit being scald and heat stimulation lasting over 1 hrs. Also, to induce the chemical stimulation, the bottom contacting with skin was coated by the extract of artemisiae argyi. The volunteers who participating in this study had taken rest for 20 - 30 mins in room temperature $(23-25^{\circ}C)$ before the examination and informed them what to prohibit smoking, drinking and administration of drug for the previous day The thermography of abdomen including a below part of the chest was taken using Infra-Red Imaging System (IR 2000, MEDI-CORE Co., Korea) by time interval of 15 minutes. Results : The results showed that moxibustion of Cheon-chu $(ST_{25})$ had more potencies of changes on all the ROIs of abdominal thermography than those of control group. Also, it was observed that the quantities of thermal changes following moxibustion of Cheon-chu $(ST_{25})$ been increased significantly comparing that of control group at all the ROIs (region of interest). Observed the thermography classified by ROI, however, moxibustion of Cheon-chu $(ST_{25})$ could modulate ipsilateral specific areas concerning to the abdominal pathway of Stomach Meridian. Conclusion : These results suggest that new non-combustible moxibusion has some similarity as like as the conventional moxibustion and moxibustion of Cheon-chu $(ST_{25})$ may modulate thermal changes of abdominal areas.

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Heat Transfer Characteristics of Water Jet Impinging on Oblique Surface (경사면(傾斜面)에 충돌(衝突) 하는 수분류(水噴流)의 열전달(熱傳達) 특성(特性)에 관(關)한 연구(硏究))

  • Choi, Guk-Gwang;Na, Gi-Dae;Kim, Yeun-Young;Jeon, Sung-Taek;Lee, Jong-Su
    • Solar Energy
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    • v.13 no.1
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    • pp.1-10
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    • 1993
  • The purpose of this research is to investigate the characteristics of heat transfer in the downward axisymmetric free water jet system impinged on a flat oblique plate which has the uniform heat flux. Experimental conditions considered were Reynolds number, distance between nozzle and Bat plate, inclination angle of heater surface and nozzle exit velocity. Local Nusselt number was subjected to the influence of Re number, Pr number, oblique angle of heating surface and local position of flat plate. In the wall region of downward surface, The secondary peak point of heat transfer appeared at the local point of X/D=-8 from the stagnation point. The stagnation heat transfer rate of this experimental study augments 2.4 times than that of laminar theorical solution. The stagnation nusselt number is function of Reynolds number, nozzle-plate spacing Prandtl number and oblique angle of impinging plate.

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