• Title/Summary/Keyword: Dry-heating

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Uncertainty Analysis of Test Method for Heat Recovery Ventilators (폐열회수 환기유닛의 인증시험 방법에 대한 오차분석)

  • Han, H.;Choo, Youn-Bok
    • Proceedings of the SAREK Conference
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    • 2006.06a
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    • pp.423-428
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    • 2006
  • Twenty nine HRV models have been tested for last two years since the attestation system has been started by KARSE. It is the objective of the present study to analyze the performance test results. Uncertainty analysis has been conducted to find the effects of measured variables on the uncertainties of test results. The uncertainty of enthalpy is found to be affected by the uncertainty of wet bulb temperature significantly, but not by that of dry bulb temperature for the present range of parameters. The uncertainty of effective enthalpy efficiency is calculated to be 6%P for the cooling condition, and 3%P for the heating condition approximately. In order to reduce the uncertainty of the test results, the uncertainty of wet bulb temperature should be minimized and the indoor/outdoor test conditions should be modified so as to increase the enthalpy difference.

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Effects of Combustor Stages on M501J Gas Turbine Combustion (M501J 가스터빈 연소기 단별 연료비율이 연소상태에 미치는 영향 고찰)

  • Yu, Won-Ju;Chung, Jin-Do
    • Journal of the Korea Safety Management & Science
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    • v.21 no.2
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    • pp.1-8
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    • 2019
  • Most of gas turbine combined cycle power plants are located in urban areas to provide peak load and district heating. However, NOx(nitrogen oxides) of exhaust gas emission from the power plants cause additional fine dust and thus it has negative impact on the urban environment. Although DLN(dry low NOx) and multi-stage combustors have been widely applied to solve this problem, they have another critical problem of damages to combustors and turbine components due to combustion dynamic pressure. In this study, the effect of different fuel ratio on NOx emission and pressure fluctuation was investigated regarding two variable conditions; combustor stages and power output on M501J gas turbine.

Assesment of Impaired Depth due to Fire of Mock-up Concrete with 21MPa Using Drying Method After Water Immersion (수중 침지 건조방법을 이용한 21MPa급 Mock-up부재 콘크리트의 화해피해 깊이진단)

  • Lim, Gun Su;Han, Jun Hui;Hyun, Seung Yong;kim, Jong;Han, Min Cheol;Han, Cheon Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2021.05a
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    • pp.241-242
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    • 2021
  • In this study, we develop the damage depth diagnostic technology of fire damage concrete and propose an method of impaired depth due to fire by drying impaired concrete after immersing. Test results indicated that when assesing impared depth due to fire with the dry method after water immersing, impaired depth was clearly found and furthermore, compared with that by Phenolphthalein method 10 mm of damage depth was additionally identified, which is imposible to asses when Phenolphthalein is applied.

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Assesment of Impaired Depth due to Fire of Mock-up Concrete with 40MPa Using Drying Method After Water Immersion (수중 침지 건조방법을 이용한 40MPa Mock-up부재의 화해피해 깊이진단)

  • Lim, Gun Su;Han, Soo Hwan;Baek, Seung Bok;Kim, Jong;Han, Min Cheol;Han, Cheon Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2021.05a
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    • pp.245-246
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    • 2021
  • In this study, we develop the damage depth diagnostic technology of fire damage concrete and propose an method of impaired depth due to fire by drying impaired concrete after immersing. Test results indicated that when assesing impared depth due to fire with the dry method after water immersing, impaired depth was clearly found and furthermore, compared with that by Phenolphthalein method 15 mm of damage depth was additionally identified, which is imposible to asses when Phenolphthalein is applied.

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Development of an Automatic Liquid Feeder for Early Weaned Piglets (조기이유 자돈용 액상사료 자동급이기 개발)

  • 유용희;정일병;안정대;이덕수;강희설;최희철;전병수;박홍석
    • Journal of Animal Environmental Science
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    • v.7 no.1
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    • pp.1-12
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    • 2001
  • This study was conducted to develope an automatic liquid feeder for early weaning piglets and to test the efficacy of the system. The liquid feeder consists of water heating and discharge unit, dry diet storing and discharge unit, mixing and discharge unit, mixed liquid feed-delivering unit, and the central control part which control each unit, feeding frequency and the amount of feeding. For investigating the possibility of practical use, a feeding trial was carried out using eighteen three way crossbred piglets weaned on 19 days of age for the experimental period of six weeks. Experimental diet was provided in liquid form using the automatic liquid feeder for the first three weeks and in dry form for the later three weeks. The water heating and discharge unit exactly supplied warm water by 27 $m\ell$/s, into the mixing unit. The dry diet storing and discharge unit supplied dry feed by 3.7g/s, into the mixing unit. Being compared with the standard growth rate suggested by NRC, average daily gain of the piglets during the first three weeks of liquid feeding was lower by 10%, while it was higher during three weeks of dry feeding and over the whole experimental period by 24 and 17%, respectively. Feed/gain was 1.09, 2.14 and 1.89 for the first 3 weeks, later 3 weeks, and whole period, respectively. Diarrhea was observed for three days from day 3 to day 7 after feeding liquid diet, but no pig died of it. In conclusion, a preliminary test for the newly developed an automatic liquid feeder using 19 days of age weaning piglets showed that the unit was successfully operated without any major problems. Piglets raised on a liquid diet through the unit developed grew less during the first three weeks, but their growth and feed intake were greatly improved thereafter, indicating the developed automatic liquid feeder may be practically used in swine industry.

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A Comparative Study of Housing Cultures between Korean-Immigrants and Australians in Melbourne, Australia (호주인과 호주교민의 주공간 사용 및 주생활을 통한 주거문화 비교에 관한 연구 - 멜버른(Melbourne)을 중심으로)

  • Lee Young-Shim
    • Journal of Families and Better Life
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    • v.24 no.1 s.79
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    • pp.159-179
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    • 2006
  • Each ethnic group has different cultural backgrounds and each culture has developed with its own traditions. The interaction between different cultures is getting more active through acculturation and cultural contacts. The purpose of this study was to compare domestic living of Korean immigrants with Australians in the form of a Cross-Cultural study. For this, usage of domestic space and seating style of 52 Korean households and 53 Australian households in Melbourne were analyzed. Ethnographic research with questionnaire was used. The results of the research were as follows. 1. The most popular type of Living-Dining-Kitchen arrangement was L+ K. D for Koreans and L. D . K for Australians. 2. A laundry room was indispensable for both and they all wanted to do ironing in there as well as dry. Both were satisfied with the type which toilet was separated from the bathroom Drain hole on the floor of the bathroom was not indispensable for most Koreans and Australians. 3. Koreans and Australians were doing various activities in living area and both were getting together around kitchen(dining) area. The particular thing of Koreans was that they were using the main bedroom with multiple purpose. 4. The seating style of Koreans and Australians belong to chair-seating style generally. But Koreans were using floor seating style in making bed for the guest and making Kimchi. Koreans and Australians were using mixed style of floor seating and chair-seating in relaxing time with watching TV, treating guest or so. 5. Koreans were not satisfied with using carpet cause of dust but Australians were satisfied with the carpet cause of warmness. 6. Most Koreans and Australians were take off shoes inside of the house. Koreans were organize shoes around the front door of the house usually and Australians were organize shoes in bedroom usually. 7. The most popular heating system was ducted heating for both. The level of satisfaction about ducted heating was low for Koreans because they though that it could contaminate air. Australians were satisfied with ducted heating because they though that this one was fit on the weather of this area. 8. Living room was the most important one for Koreans and Australians and they also thought it should be decorated well for entertaining guests. Most Koreans were estimate that the brightness of the light of the house was not enough but it was estimated to moderate for Australians on the contrary.

The Physico-chemical Characteristics of Municipal Solid Wastes from Four Different Sources in Daegu City (대구시의 지역별 생활쓰레기 성상 및 특성)

  • No, Sook-Hyun;Lee, Dong-Hoon;Choi, Chung-Ryul;Park, Man;Park, Byung-Yoon;Choi, Jung
    • Journal of Environmental Science International
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    • v.12 no.4
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    • pp.461-467
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    • 2003
  • This study was conducted to provide the basic information to know reasonable method f3r the removal and treatment of municipal solid wastes(MSWs). MSWs four different sources(apartment residence, commerce, office/industry) in Daegu city were collected, and bulk density, physical composition, moisture, combustible, ash, elements and heating values were investigated. The values of bulk density were at range of 0.30∼0.41ton/m$^3$. The percentages of foods, papers, vinyls/plastics, textiles, rubbers/leathers, metals and glasses/ceramics of wet muncipal solid wastes from three sources except office/industry were at range of 27.3∼46.4%, 21.2∼38.4%, 10.3∼11.9%, 3.8∼5.2%, 0.5∼1.7%, 6.9∼8.7% and 1.9∼2.6% respectively. The percentages of papers, foods, vinyls/plastics, textiles, rubbers/leathers, metals and glasses/ceramics of dry muncipal solid wastes from three sources except office/industry were at range of 21.1∼40.4%, 14.2∼30.1%, 15.2∼17.8%, 4.0∼6.0%, 0.9∼2.8%, 12.2∼14.1% and 3.1∼3.7% respectively. The moisture contents of foods, woods, textiles and papers in wastes were at range of 65.7∼76.2%, 34.6∼50.0%, 22.2∼44.8 and 30.6∼44.4% respectively. The carbon contents of vinyls/plastics, rubbers/leathers, textiles, woods, papers and foods in wastes were at range of 75.88∼79.87%, 58.24∼70.74%, 45.23∼51.63%, 42.29∼45.58%, 40.19∼48.4% and 25.86∼36.25% respectively. The low heating values of foods, papers, woods, textiles, rubbers/leathers and vinyls/plastics by Dulong's law were at range of 178∼1,353kcal/kg, 770∼1,660kcal/kg, 995∼1,629kcal/kg, 2,133∼2,432kca1/kg, 4,200∼7,275 kcal/kg and 6,384∼8,722kcal/kg respectively, and the high heating values of them were at range of 782∼2,056 kcal/kg, 2,459∼3,314kca1/kg, 3,056∼3,592kcal/kg, 4,381∼5,087kca1/kg, 5,005∼8,066kca1/kg and 10,032∼10,739 kcal/kg respectively.

Growth and Berry Quality of 'Kyoho' Grapes in Double Cropping System as Affected by Root Zone Heating and CO2 Enrichment in Plastic Greenhouse ('거봉' 포도 2기작 재배 시 근권 가온 및 CO2 시용이 생장 및 과실 품질에 미치는 영향)

  • Oh, Sung Do;Kim, Yong Hyeon;Choi, Dong Geun
    • Horticultural Science & Technology
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    • v.19 no.3
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    • pp.367-372
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    • 2001
  • 'Kyoho' grape (Vitis labruscana L.) has currently cropped twice a year in plastic greenhouses. However, there are problems with low fruit quality in the second cropping owing to low temperatures and short photoperiods. This experiment was conducted to investigate the effect of root zone heating and $CO_2$ enrichment in plastic greenhouse on the vine growth and fruit quality of 'Kyoho' grape in double cropping system. The internode length of shoots, leaf area and leaf dry weight at the treatment of soil heating near root zone was significantly different regardless of $CO_2$ enrichment. There were no significant differences in fruit bunch and berry weight, titratable acidity, coloration degree and berry shattering among the treatments, but the soluble solids significantly increased by root zone heating. Photosynthetic rate increased with increasing $CO_2$ concentration from 300 to $800{\mu}mol{\cdot}mol^{-1}$ in sunny day, whereas it didn't increase in cloudy day regardless of $CO_2$ enrichment.

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Effect of Immersion and High Temperature on Shear Strength of Cemented Sand (수침 및 고온이 고결모래의 전단강도에 미치는 영향)

  • Moon, Hong Duk;Hwang, Keum-Bee;Kim, Tae-hun;Park, Sung-Sik
    • Journal of the Korean Geotechnical Society
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    • v.39 no.7
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    • pp.17-30
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    • 2023
  • This study investigates the impact of water immersion and high temperature on the shear strength of cemented sand through direct shear tests. Standard Jumunjin sand was used and cemented with binders, such as ultra-rapid hardening cement and an epoxy aqueous solution. The binder was mixed at concentrations of 4%, 8%, or 12%. Subsequently, cylindrical cemented specimens with a diameter of 64 mm and height of 25 mm were produced using compaction. The curing period was three days, and the specimens were cured under dry air, immersion, and heating conditions. The heating condition involved subjecting the immersed specimens to a microwave oven three times for three minutes to achieve an internal temperature of approximately 90℃. Regardless of the binder type, the cohesion of the cemented sand increased with higher binder content, whereas the internal friction angle exhibited a slight increase or decrease. Compared with ultra-rapid hardening cemented sand, epoxy-cemented sand displayed an average cohesion that was five times higher and an internal friction angle that was 10° higher. Overall, irrespective of binder type, the shear strength decreased during water immersion and increased during heating. Notably, the epoxy-cemented sand exhibited a three-fold increase in cohesion and a more than 20° increase in the internal friction angle during heating.

Study of Heating Temperature and Quantification Conditions of Standard Water for Evaluating Hair Water Content (모발 수분 함량 평가를 위한 가열 온도와 기준 수분 정량 조건 연구)

  • Sang-Hun Song;Jangho Joo;Hyun Sub Park;Seong Kil Son;Nae-Gyu Kang
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.50 no.1
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    • pp.11-18
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    • 2024
  • Recently, there have been attempts to claim the hair moisturizing effect for a hair care product, however there has not yet been an official evaluation method because heating temperature for hair has not been established. This study was conducted to establish a quantitative evaluation for hair water content. In order to observe the behavior of water inside hair, heat was applied to hair with various temperatures using thermogravimetric dry residue. As the heating temperature increased, the amount of moisture released from the hair increased. As a result of evaluating hair using a differential scanning calorimeter (DSC), a unique phenomenon in which a rapid endothermic reaction occurs around 75 ℃ was observed. This phenomenon was also observed in different ethnic hair. In hair that damaged the hair cuticle barrier with oxidation and heat, this rapidly rising endothermic reaction temperature occurred at 77 ℃, which was slightly higher, and 73 ℃ was observed when this hair was applied with polar oil, conditioning polymer, or keratin protein. To determine how this reaction affects the hair surface, friction test was performed using an atomic force microscope. When heated above 75 ℃, cuticle friction increased, however when heated above 90 ℃, there was no change in hair cuticle friction. Finally, it was confirmed that around 75 ℃ is the critical temperature at which desorption of water bound to the hair occurs. It is suggested that a heating temperature of 75 ℃ is the optimal temperature for detecting and quantifying the moisture content of hair, and that approximately 10% detected at 75 ℃ can be a standard value for hair moisture content.