• Title/Summary/Keyword: Heat Treatment History

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Measurements of Heat Transfer Distribution in Spray Cooling of Hot Steel Plate . (분무냉각에 의한 강판 열처리과정에 있어서 열전달분포의 측정)

  • 김영찬;유갑종;서태원
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.12 no.10
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    • pp.886-893
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    • 2000
  • A good understanding of the heat transfer distribution is very important to suppress the deformation of steel products. In this study, the local heat transfer coefficients are experimentally investigated to understand the heat transfer distribution of thick steel plates with even flat spray nozzle. The steel slabs are cooled down from the initial temperature of about $1000^{\circ}C$ , and the local heat transfer coefficients and surface temperatures are calculated from the measured temperature-time history. The results show that the local heat transfer coefficients of spray cooling are dominated by the local droplet flow rate, and in proportion to becoming more distant from the center of heat transfer surface, the local heat transfer coefficients decrease with the decrease of the local droplet flow rate.

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Study on Minimum Heat Flux Point in Spray Cooling of Hot Plate (고온 강판의 분무냉각에 있어서 MHF 점에 관한 연구)

  • Kim, Yeung-Chan
    • Proceedings of the KSME Conference
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    • 2001.06d
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    • pp.175-180
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    • 2001
  • In this study, the minimum heat flux conditions are experimentally investigated for the spray cooling of hot plate. The hot plates are cooled down from the initial temperature of about $900^{\circ}C$, and the local heat flux and surface temperatures are calculated from the measured temperature-time history. The results show that the minimum heat flux point temperatures increase linearly resulting from the propagation of wetting front with the increase of the distance from the stagnation point of spray flow. However, in the wall region, the minimum heat flux point temperature becomes independent of the distance. Also, the experimental results show that the velocity of wetting front increases with the increase of the droplet flow rate.

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Study on Minimum Heat Flux Point in Spray Cooling of Hot Plate (고온 평판의 분무냉각에 있어서 MHF점에 관한 연구)

  • 김영찬
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.13 no.10
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    • pp.974-981
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    • 2001
  • In this study, the minimum heat flux conditions are experimentally investigated for the spray cooling of hot plate. The hot plates are cooled down from the initial temperature of about$ 900^{\circ}C$, and the local heat flux and surface temperatures are calculated from the measured temperature-time history. The results show that the minimum heat flux point temperatures increase linearly resulting from the propagation of wetting front with the increase of the distance from the stagnation point of spray flow. However, in the wall region, the minimum heat flux point temperature becomes independent of the distance. Also, the velocity of wetting front increases with the increase of the droplet flow rate.

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Effects of Heat Treatment History of Skim Milk Powder on the Quality Characteristics of RTD Coffee with High Protein (탈지분유의 열처리 공정이 고단백질 RTD 커피의 품질 특성에 미치는 영향)

  • Ko, Bong Soo;Lee, Seok Ryong;Han, Sung Hee
    • Culinary science and hospitality research
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    • v.24 no.1
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    • pp.24-30
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    • 2018
  • This study investigated the quality of characteristics of high-protein RTD coffee using domestic and imported skim milk powder with different heat treatment. Skim milk powders (A, B) had high-heat treatment, C had medium-heat, and D and E had low-heat treatment. The transmittance of A and B were higher than that of C, and that of C were higher than that of D and E (p<0.05). The precipitate attached on bottom of container of RTD coffee using A and B were 2.993~3.053% and higher than those (0.753~0.803%) of RTD coffee using C, D and E (p<0.05), but there was no difference between those of RTD coffee using C, D and E (p<0.05). The centrifuged precipitate of RTD coffee using A and B were 1.987~2.040% and higher than those (0.820~0.830%) of RTD coffee using C, D and E (p<0.05), but there was no difference between those of RTD coffee using C, D and E (p<0.05). The proximate composition of precipitate attached on bottom of container of RTD coffee using A, which showed the highest amount of precipitate, showed 65.7% of carbohydrate, 19.0% of protein, 4.8% of fat and 4.8% of ash in dry basis, that of RTD coffee being 72.7%, 15.1%, 7.9% and 4.3% in dry basis respectively. Protein and fat content of precipitate were lower and protein and ash content were higher than those of RTD coffee. But seeing that the most increased portion was protein, precipitation of RTD coffee appears to be attributed to heat-denatured proteins.

The Study on the "Sanghanron(傷寒論)"'s Mahanggamsuktang(麻杏甘石湯) ("상한론(傷寒論)"의 마행감석탕(麻杏甘石湯)에 대한 연구(硏究))

  • Bang, Jung-Kyun
    • Journal of Korean Medical classics
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    • v.25 no.1
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    • pp.163-171
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    • 2012
  • Objective : There are lots of wrong treatment cases in the "Sanghanron". Therefore, search the symptoms that before performed the wrong treatment is important, and that can be a another way to study "Sanghanron". Method : I'll have to figure out "Sanghanron" related publications. Result : The symptoms of Mahanggamsuktang already had the symptoms of Mahwantang(麻黃湯) and the fever of Lung before performed the wrong treatment. Because pathogenic heat is blockaged in the Lung, so we use the Mahanggamsuktang. Conclusion : The efficacies of this drug are disseminating Lung Gi(肺氣) and clearing heat. However, as the rise and fall of fever, the amount of HERBA EPHEDRAE(麻黃) and GYPSUM FIBROSUM(石膏) can be adjusted.

Study on evolution in smallpox therapy until 17th century in Europe (17세기이전 유럽에서 -시두 대처방법의 변천 과정에 대한 고찰)

  • Yun, Suk-Hyun;Kim, Yong-Jin
    • Journal of Haehwa Medicine
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    • v.19 no.2
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    • pp.1-12
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    • 2011
  • 21th century is a era of new pandemic. We are facing a new challenge and need a new way of approach. But eastern medicine and western medicine is clinging to their own way and have no intention to hear other one's opinion. Before the invention of the vaccination, smallpox has always been a major problem. Intellectuals in every country tried their best to find the treatment for the smallpox, and for Europian, didn't hesitate to borrow some knowledge of the pagon. Romans adopted the Galens concept, running away from the epidemic lesion. Christianity made smallpox Saints, and later adopted Razes heat therapy. But in the 17th century, these methods didn't turn out well, so they needed a new way of approach. By this movement, they had adopted the Chinese inoculation concept and invented a vaccination, By studying the effort of the Europian intellectuals who had tried their best to find the treatment for the smallpox until 17th century, we might get a glimps of wisdom which they had shown us. By this paper we can feel the passion to learn new techniques and their open mind and courage, which might be also needed in the 21th century, era of new pandemic.

Effect of Thermal History on Pitting Corrosion of High Nitrogen and Low Molybdenum Stainless Steels

  • Kim, Kwangsik;Chang, Hyunyoung;Kim, Youngsik
    • Corrosion Science and Technology
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    • v.2 no.2
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    • pp.75-81
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    • 2003
  • Chromium, molybdenum. and nitrogen are very important alloying elements in stainless steels and its effect was approved in pitting resistance equivalent (PRE) equations and many experimental results. However, Cr can improve the corrosion resistance, but facilitate the formation of sigma phase. Also. Mo has the same effect in stainless steels. If Cr and Mo are added at high amount to increase the corrosion resistance of stainless steel, corrosion resistance in annealed alloys can be improved, but in case of welding or aging heat treatment. its resistance will be drastically decreased. In this work, increasing Cr and N contents but decreasing Mo than the commercial alloys made the experimental alloys. Typical alloys are 25Cr-4.5Mo-0.43N alloy, 27Cr-4.7Mo-0.4N alloy, 27Cr-5.3Mo-0.25N alloy, 32Cr-2.6Mo-0.36N alloy. After annealing and aging heat treatment, microstructures, anodic polarization test, and pitting corrosion test were performed. Annealed alloys showed $100^{\circ}C$ of CPT and aged alloys showed the different tendency depending upon Cr and Mo contents(SFI)

A Literature study about comparison of Eastern-Weatern medicine on the Atopic dermatitis (아토피 皮膚炎의 洋.韓方的 考察)

  • Gong, Nam-mi;Jee, Seon-Young
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.12 no.1
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    • pp.241-253
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    • 1999
  • The results of the study about comparison of Eastern-Western medicine on the Atopic dermatitis were as follows. 1. Atopic dermatitis is chronic eczematous dermatosis which have severe itching, characteristic eruption, easily occur region and pass on chronic relapsing progress and have family history of Atopic disease and hereditary disposition. 2. Atopic dermatitis assume an remarkable clinical aspect and it's diagnosis depends on family history and clinical symptom. 3. In all cases of Western medical treatment is nothing but a symptomatic treatment because can not find out certainly the cause of Atopic dermatitis. 4. Atopic dermatitis is belong to the category of the 'Naesun(내癬)', 'Taeryumchang(胎斂瘡)', 'Samanpoong(四灣風)' etc. in Oriental medicine. 5. The etiology and pathogenesis of Atopic dermatitis in oriental medicine are congenital defect(稟賦不足), internal accumulation of damp and heat(濕熱內鬱), improper diet(飮食不節), exogenous pathogenic factors(外邪侵襲), etc.. 6. The treatments of Atopic dermatitis in oriental medicine are thought effective clear up heat and remove dampness with febrifugal arld diuretic drug(淸熱利濕), invigorate the spleen to resolve dampness(健脾燥濕), nourish Um and blood to relave dryness(滋陰養血潤燥), etc..

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Material Properties of Structural Steel used in Modern Historical Heritage of Busan and Gyeongsang in the 1930-1940s (1930-40년대 부산·경상지역의 근대 역사문화유산에 사용된 강재의 재료적 특성)

  • Ahn, Jae-Cheol;Song, Jong-Mok
    • Journal of architectural history
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    • v.23 no.6
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    • pp.39-46
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    • 2014
  • In this study, we evaluated the chemical and physical properties of structural steel, which is the most basic material for steel structures and reinforcement concrete structures in modern period. We theorized the technical data for the research of technical history of modern heritage structures by analyzing the product system and its quality control of structural steel used in modern historical heritages. The results of this study are as follow; first, the rounded bars were used in most of modern heritage structures. But in the case of Waegwan railroad bridge, the deformed bars were used in spit of not using in Japan after the great earthquake of Kantou. Second, the structural steel was good in terms of quality control, but It has brittle properties because it was not manufactured by heat treatment process.

Thermal Stability of TiN/Ti Barrier Metals with Al Overlayers and Si Substrates Modified under Different Annealing Histories (형성조건에 따른 TiN/Ti Barrier Metal의 Al 및 Si 과의 열적 안정성)

  • 신두식;오재응;유성룡;최진석;백수현;이상인;이정규;이종길
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.30A no.7
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    • pp.47-59
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    • 1993
  • The thermal stability of "stuffed" TiN/Ti barrier matals with different annealing history has been studied to improve the contact reliability of Al/Si contacts in 16M DRAM. The annealing conditions before the Al deposition such as film thickness, the annealing temperature and the annealing ambient have been varied. For TiN(900A)/Ti(300A) annealed at 450 in nitrogen ambient to form a "stuffed barrier" by inducing oxygen atoms into grain boundaries, there is no observation of Al penetrations into Si substrates after the post heat treatment of up to 700 even though there are massive amounts of Al found in TiN film after the post heat treatment of 600 indicating that TiN has a "sponge-like" function due to its ability to absorb several amounts of aluminum at elevated temperature. The TiN/Ti diffusion barrier annealed at 550 has, however, failed after the post heat treatment at 600. The thinner diffusion barriers with TiN(300A)/Ti(100A) failed after the post heat treatment at 600.he post heat treatment at 600.

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