• Title/Summary/Keyword: Secondary formation

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EFFECTS OF SPLIT INJECTION AND OXYGEN-ENRICHED AIR ON SOOT EMISSIONS IN A DIESEL ENGINE

  • Nguyen, Khai;Sung, Nak-Won;Lee, Sang-Su
    • Proceedings of the KSME Conference
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    • 2008.11b
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    • pp.2965-2970
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    • 2008
  • Effects of split injection and oxygen-enriched air on soot emissions in a DI diesel engine were studied by the KIVA-3V code. When split injection is applied, the second injection of fuel into a cylinder results in two separate stoichiometric zones which increases soot oxidation. As a result, soot emissions are decreased with split injection. When oxygen-enriched air is applied together with split injection, higher concentration of oxygen helps secondary combustion which results in a higher temperature in the cylinder. The increased temperature promotes growth reaction of acetylene with soot but doesn't improve the acetylene formation during the second injection of fuel. As more acetylene is consumed in the growth reaction of acetylene, the net acetylene mass in the cylinder is decreased, which leads to a decrease of soot formation. With an increase of soot oxidation caused by split injection, the soot emissions are decreased significantly. However, to avoid excessive NOx emissions with increased oxygen concentration, the level of oxygen concentration should be lower than 22% in volume.

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Multiple Ascending Aortic Mural Thrombi and Acute Necrotizing Mediastinitis Secondary to Acute Pancreatitis

  • Chong, Byung Kwon;Yun, Jae Kwang;Kim, Joon Bum;Park, Do Hyun
    • Journal of Chest Surgery
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    • v.49 no.5
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    • pp.401-404
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    • 2016
  • The formation of aortic thrombi is an extremely rare complication of acute pancreatitis. Here we report a case of acute pancreatitis complicated by a paraesophageal pseudocyst, necrotizing mediastinitis, and the formation of multiple thrombi in the ascending aorta. The patient was successfully treated by surgical therapy, which included extensive debridement of the mediastinum and removal of the aortic thrombi under cardiopulmonary bypass. Although esophageal resection was not carried out concomitantly, the lesions were resolved and the patient remained free of complications over 2 years of follow-up care.

Effect of Matrix Phase on the Abrasive Wear Behavior of the High Cr White Iron Hardfacing Weld Deposites (고크롬 철계 오버레이용접층의 긁힘마모거동에 미치는 기지상의 영향)

  • 백응률
    • Journal of Welding and Joining
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    • v.16 no.1
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    • pp.114-124
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    • 1998
  • The effect of matrix phase (austenite, pearlite, martensite) on the low stress abrasion resistance in the chromium-carbide-type high Cr white iorn hardfacing weld deposites has been investigated. In order to examine matrix phase, a series of alloys with different matrix phase by changing the ratio of Cr/C system by heat treatment were employed. The alloys were deposited twice on a mild steel plate using self-shielding flux cored arc welding process. The low stress abrasion resistance of the alloys against sands was measured by the Dry Sand/Rubber Wheel Abrasion Test(RWAT). Even though formation of pearlite phase in the matrix showed higher hardness than that of austenite, there was no observable difference in wear resistance between the pearlite and austenite phase for the same amount of chromium-carbide in the matrix. On the other hand, the formation of martensitic phase,, from heat treated austenitic alloys (high content of Cr), enhanced wear resistance due to its fine secondary precipitates.

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Photochemical C$_4$-Cycloadduct Formation between 5(E)-Styryl-1,3-dimethyluracil and Some Olefins-Via Photochemical Diels-Alder Type [4 + 2] Adduct

  • Shim, Sang-Chul;Shin, Eun-Ju
    • Bulletin of the Korean Chemical Society
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    • v.8 no.5
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    • pp.376-380
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    • 1987
  • The cyclobutane forming photocycloaddition reaction of 5(E)-styryl-1,3-dimethyluracil with some olefins occurs on the 5,6-double bond of uracil ring rather than the expected central double bond via an intermediate, probably the photochemical Diels-Alder type adduct. This intermediate formed on short term irradiation of 5(E)-styryl-1,3-dimethyluracil and 2,3-dimethyl-2-butene solution is converted into the $C_4$-cycloadduct on the prolonged irradiation. Quantum yield of the intermediate formation is not linear with the concentration of 2,3-dimethyl-2-butene probably due to the secondary reaction accompanied with the complex reaction kinetics. The intermediate is formed from the lowest excited singlet state.

The value of artistic expression and the effect application of human education and therapy (예술적 표현의 가치와 인성교육 및 치료의 효과와 적용)

  • Jung, Kil- Young
    • Philosophy of Education
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    • no.49
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    • pp.235-270
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    • 2013
  • The aim of this study is to make clear the significance of art education for solving problem in elementary and secondary school. These days, our students have so many negative problems in school and society, for example, school violence, group teasing, group outcasts, arrogate teacher's authority, school collapse, dehumanization get soused excessive and such like. We must support to make humanization through a normal art education and art class. Art, music, physical and literature education is a good methods for human education and mental therapy. The best art education is enlightening the children's imagination and curiosity. To enlighten. in art class at the school, teachers must think about enlightening the children's imagination and curiosity. Aesthetic experience includes creative activities and appreciative activities for human formation. The school must expend effort to increase the art class in each week, because students can change positively in aesthetic experience and aesthetic environment.

Potential of Cells and Cytokines/Chemokines to Regulate Tertiary Lymphoid Structures in Human Diseases

  • Feifeng Jing;Eun Young Choi
    • IMMUNE NETWORK
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    • v.16 no.5
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    • pp.271-280
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    • 2016
  • Tertiary lymphoid structures (TLS) are ectopic lymphoid tissues involved in chronic inflammation, autoimmune diseases, transplant rejection and cancer. They exhibit almost all the characteristics of secondary lymphoid organs (SLO), which are associated with adaptive immune responses; as such, they contain organized B-cell follicles with germinal centers, distinct areas containing T cells and dendritic cells, high endothelial venules, and lymphatics. In this review, we briefly describe the formation of SLO, and describe the cellular subsets and molecular cues involved in the formation and maintenance of TLS. Finally, we discuss the associations of TLS with human diseases, especially autoimmune diseases, and the potential for therapeutic targeting.

A Study on the Placeness Formation of Elementary and Secondary School Students in School Libraries (학교도서관에 대한 초·중등 학생의 장소성 형성구조에 관한 연구)

  • Lee, Byeong-Kee
    • Journal of Korean Library and Information Science Society
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    • v.48 no.2
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    • pp.73-97
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    • 2017
  • School Library is both a space and a place. The difference between space and place is the same as in the difference between house and home. Space may be described in terms of physical shape. Place is concept that formulated by personal experience. The social and cognitive developmental stages of elementary, middle and high school students are different, so the placeness or sense of place may be different. The purpose of this study is to figure out the differences in elementary and secondary school student's formative factors of placeness and examine the process that those factors are connected to the results of the user behavioral intentions through the medium of place attachment, place value perception. The data are collected from 590 students and analyzed by SPSS 19 and AMOS 19. The results of this study are as follows. The physical, active behavioral and psychological factors affect on placeness formation of elementary and secondary school students in school libraries. Elementary school students are significantly affected more by physical factors, active behavioral factors than middle and high school students. This study confirmed the process that those factors are connected to the results of the user behavior through the medium of place attachment, place value perception.

A study on Ultrashallow PN junction formation by boron implantation in Silicon (실리콘에 Boron 이온 주입에 의한 Ultrashallow PN접합 형성에 관한 연구)

  • 김동수;정원채
    • Proceedings of the IEEK Conference
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    • 2000.06b
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    • pp.56-59
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    • 2000
  • In this paper, we have made a comparison between secondary ion mass spectroscopy(SIMS) data by the 5kcV-15keV boron implantation and computer simulation results. In order to make electrical activation of implanted carriers, thermal annealing are carried out by RTP method for 30s at 1000$^{\circ}C$ Two dimensional doping concentration distribution from different mask dimensions under inert gas annealing, dry-, and wet-oxidation condition were calculated and simulated with microtec simulator.

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