• Title/Summary/Keyword: Process Chamber

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Trend in the Developments of Liquid Rocket Engine In Russia and Ukraine (러시아와 우크라이나의 액체로켓엔진 개발 동향)

  • Kim, C.W.;Cho, W.K.;Park, S.Y.;Seol, W.S.
    • Current Industrial and Technological Trends in Aerospace
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    • v.8 no.2
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    • pp.86-97
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    • 2010
  • This paper treats with the history and current trends in the developments of liquid-propellant rocket engine in Russia and Ukraine which are among world leaders in the technology of liquid rocket engine(LRE). In 1960s formerly the Soviet Union accepted the closed cycle engine for increasing the pressure in the combustion chamber and specific impulse to the maximum. However, since financially difficult times after 1990, they have decreased the cost for the development of new rocket engines. It was achieved by using existing units for new developed engines and minimizing the total number of engines and tests through the reasonable planning in the process for the experimental improvement of LRE. In addition, nowadays international cooperation in supplying LRE for commercial rocket and development of next generation LRE, such as 3 components engines and mathane engines, are proceeding.

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Ammonia Emission and Nitrogen and Phosphorous Loss by Rainfall from Cow Manure Pile (우분 야적시 암모니아 휘산량과 강우에 의한 질소 및 인산 유출량 평가)

  • Yun, Hong-Bae;Lee, Youn;Lee, Sang-Min;Kim, Suk-Chul;Hong, Seung-Gil;Lee, Yong-Bok
    • Korean Journal of Environmental Agriculture
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    • v.28 no.4
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    • pp.392-396
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    • 2009
  • For the reduction of ammonia ($NH_3$) volatilization from the cow manure composting process, a cow manure pile was covered with vinyl (white polyethylene) and the ammonia emissions were evaluated using the dynamic chamber system for 47 days. Nitrogen and phosphorus loss from cow manure pile by rainfall was also measured in this study. In the cow manure pile without covering, the amount of $NH_3$ emission was 0.78 N kg/Mg which accounted for 9.4% of total nitrogen contents in the cow manure. Eighty nine percent of the total $NH_3$ emission during experimental period from the cow manure pile without covering was emitted for the first 21 days. The vinyl covering of cow manure pile reduced 91% of $NH_3$ emission compared to the pile without covering. The amounts of nitrogen and phosphorus loss by rainfall from cow manure pile without covering were 1.27 N kg/Mg and 0.23 P kg/Mg for 47 days, respectively. Results from this study demonstrated that vinyl covering of cow manure pile could reduce $NH_3$ emission and loss of nitrogen and phosphorus by rainfall during composting.

A Study on General Principles of the ICC Publication No.645(International Standard Banking Practice) (국제상업회의소 발간물 제645호(국제표준은행관습)에 관한 일고(一考))

  • Kim, Young-Hoon
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.22
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    • pp.3-48
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    • 2004
  • Many presentations of documents are rejected because credits have been incorrectly issued. One reason of rejecting the documents is related with error in application stage of L/C. Errors may take the form of mismatches between the terms of the sales contract and the provisions stipulated in the credit. Thus, Article 5 encourages applicants to make their contribution to the smooth running of the letter of credit process by being unambiguous and brief. Another reason that the banks reject the documents relates to the ambiguity of the term "International Standard Banking Practice" That is to say, UCP500 Art.13 introduced the term "International Standard Banking Practice"(ISBP) without the definition so that one wonder what ISBP is or how ISBP apply in daily work of bankers, examination of documents. From hence, International Chamber of Commerce(ICC) started the work to document ISBP at May 2000, finally approved the result last year and published the publication titled "International Standard Banking Practice for the examination of documents under documentary credits." By applying ISBP in document examination stage, I expect that the freqency of rejecting the documents grow less and bankers' work of examination become easy. On the other hand, ISBP is supplement to UCP500 so that the interpretation of ISBP is made on the basis of understanding of UCP and its underlying principles. So, I reviewed each paragraphs of ISBP on this basis and tried to indicate contradiction between ISBP and UCP500. But because of reading not enough, I failed to search the connotative sense many paragraphs have.

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Emerging Electronic Documentary Credit and Electronic Presentation of Documents (전자신용장의 출현과 서류의 전자적 제시에 관한 고찰)

  • Kang, Won-Jin
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.21
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    • pp.73-97
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    • 2003
  • In this paper, I examined the trends of standardization and electronization of trade documents and SWIFT network. Also, I reviewed on emerging electronic documentary credit for electronic payment and electronic presentation of documents. New international trade customs and practices are being established and changed as a result of the growth of the Internet and other on-line networks. At the same time there is increasing pressure to move from existing paper-based documentary credit to electronic documentary credit. Several projects devoted to development of an electronic letter of credit infrastructure have recently been proposed such as Bolero, SWIFTNet, UNeDocs and eUCP, etc. Yet, little can be done until the presentation process is electrified between traders and banks. Also, interbank communication of letters of credit has long been electronic, mainly through the SWIFT. However, it is not functioned between applicant and beneficiary, although the solution of SWIFTNet has recently been developed. The Banking Commission of International Chamber of Commerce established a working group consisting of experts in the related fields to prepare the appropriate rules as a Supplement to UCP 500 for Electronic Presentation: eUCP. The eUCP will provide the necessary rules for the presentation of the electronic equivalents of paper documents under letters of credit. Some problems of electronic presentation under the eUCP, exist such as format, presentation of electronic records and the way of beneficiary's notice for completeness under the Article e5 if more than one record is to be presented electronically by third parties. Therefore, it is encouraged to provide more detailed guide for eUCP Article e5.

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A Experimental Study on the Effects of the Impingement-wall on the Spray and Combustion Characteristics of Direct-Injection LPG (충돌벽면이 직분식 LPG의 분무 및 연소 특성에 미치는 영향에 관한 실험 연구)

  • Hwang, Seong-Ill;Chung, Sung-Sik;Yeom, Jeong-Kuk
    • Journal of Power System Engineering
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    • v.19 no.2
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    • pp.49-56
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    • 2015
  • As an alternative fuel that can be used in SI engine, LPG is one of clean fuels with larger H/C ratio compared to gasoline, low $CO_2$ emission, and small amount of pollutants such as sulfur compounds. When LPG is used in spark ignition engine, volumetric efficiency of the engine can be improved and pumping loss can be reduced by performing direct injection into the combustion chamber instead of port fuel injection. LPG-DI engine allows for lean combustion and stratified combustion under low load. In case of stratified combustion, air fuel ratio can be greatly increased compared to theoretic mixture ratio combustion. Improved thermal efficiency of the engine and reduced pumping loss can be expected from stratified combustion. Accordingly in this study, an experimental apparatus for visualization was designed and manufactured to study the combustion process of LPG after injection and ignition, intended to examine ignition probability and combustion characteristics of spark ignition direct injection(SIDI) LPG fuel. Ambient pressure, ambient temperature and fuel injection pressure were found as important variables that affect ignition probability and flame propagation characteristics of LPG-air mixture. Also, it was verified that the injected LPG fuel can be directly ignited by spark plug under appropriate ambient conditions.

EFFECTS OF CONVERGENT ANGLE OF NOZZLE CONTRACTION ON HIGH-SPEED OPTICAL FIBER COATING FLOW (노즐 축소부 수렴각이 고속 광섬유 피복유동에 미치는 영향)

  • Park, S.;Kim, K.;Kwak, H.S.
    • Journal of computational fluids engineering
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    • v.21 no.4
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    • pp.11-18
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    • 2016
  • A numerical study is conducted on the optical fiber coating flow in a primary coating nozzle consisting of three major parts: a resin chamber, a contraction and a coating die of small diameter. The flow is driven by the optical fiber penetrating the center of the nozzle at a high speed. The axisymmetric two-dimensional flow and heat transfer induced by viscous heating are examined based on the laminar flow assumption. Numerical experiments are performed with varying the convergent angle of nozzle contraction and the optical fiber drawing speed. The numerical results show that for high drawing speed greater than 30 m/s, there is a transition in the essential flow features depending on the convergent angle. For a large convergent angle greater than $30^{\circ}$, unfavorable multicellular flow structures are monitored, which could be associated with wall boundary-layer separation. In the regime of small convergent angle, as the angle increases, the highest resin temperature at the exit of die and the coating thickness decrease but the sensitivity of coating thickness on drawing speed and the maximum shear strain of resin on the optical fiber increase. The effects of the convergent angle are discussed in view of compromise searching for an appropriate angle for high-speed optical fiber coating.

An Analytical Study on Characteristics of a Diesel Injection System (디젤분사계의 특성에 관한 해석적 연구)

  • 장영준;박호준;전충환
    • Journal of Advanced Marine Engineering and Technology
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    • v.13 no.4
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    • pp.63-74
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    • 1989
  • It is well-known that the fuel injection system if a diesel engine has taken a more important place in understanding of diesel combustion process with combustion chamber. But a diesel fuel injection system has an assembly of many complex and intricate problems such as the desired rate of injection, secondary injection and injection pump etc., in addition to the atomization for ignition and combustion, the penetration and diestribution for proper utilization of air. The analysis is carried out by simplifing and modeling the injection phenomena and dividing into three parts comprising of fuel injection pump, high pressure pipe and fuel injection nozzle. The purpose of this paper is to describe an analytical simulation of the injection system and to speed up the work of developing injection systems for new engines. The effects of important injection parameters as predicted by the present model are found to be in good agreement with experiment. It can be seen that there is an optimal pipe diameter for maximum quantity injected.

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Production of Reuterin by Batch and Continuous Reactor and Antimicrobial Characteristics of Reuterin (회분식과 연속식에 의한 루테린 생산 및 루테린의 항균 특성)

  • Yum, Eun-Mi;Kim, Ji-Yeun;Shin, Hyun-Kyung;Ji, Geun-Eog
    • Korean Journal of Food Science and Technology
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    • v.36 no.1
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    • pp.111-115
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    • 2004
  • Reuterin production efficiency of Lactobacillus reuteri, which converts glycerol into reuterin (antimicrobial substance) under anaerobic condition, was examined. When compared at $32,\;37,\;and\;42^{\circ}C$, production rate and total amount produced increased with increasing incubation temperature. Reuterin production terminated earlier at $42^{\circ}C$ than at $32\;and\;37^{\circ}C$. Presence of various amino acids in the reaction mixture generally decreased reuterin production, whereas proline did not inhibit reuterin production. A continuous-type reactor in which glycerol was passed through the chamber containing L. reuteri cells produced greater amount of reuterin than when batch-type process was used.

Anatomical and physiological changes in the aging eye (노인성 변화에 따른 안구와 해부생리학적 고찰)

  • Kim, Jai-Min;Seong, Jeong-Sub;Seo, Eun-Sun;Kho, Eun-Kyung;Lee, Seok-Ju;Yoo, Geun-Chang
    • Journal of Korean Ophthalmic Optics Society
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    • v.9 no.1
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    • pp.135-143
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    • 2004
  • The Human body is subject to two patterns of senescence, both of which are represented in the eye and vision. This article discusses the anatomical and physiological changes in anterior and posterior segments which occur with age. The areas covered include the globe, lids, tears, conjunctiva, cornea, sclera, anterior chamber angle, iris, lens, choroid, vitreous and retina. A sample of 219 individuals between the ages of 50 and 79 years was tested with case history, slit lamp examination, palpebral fissure, horizontal visible iris diameter(HVID) and pupil size. The palpebral fissure decreases with age while HVID remains constant in all age classes. This study suggests that an understanding of anatomical and physiological changes which occur with age is helpful to all eye clinicians because the aging process affects all of the ocular tissues.

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A Study on the Provisions of the CIP·DDP·CIF in the Incoterms 2010 Coping with Their Problems and Alternatives (Incoterms 2010 CIP·DDP·CIF 규정상의 문제점과 대안에 관한 연구)

  • OH, Se-Chang;PARK, Sung-Ho
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.65
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    • pp.1-20
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    • 2015
  • International Commercial Terms, known as "Incoterms", are internationally accepted terms defining the responsibilities of exporters and importers in the arrangement of shipments and the transfer of liability involved at various stages of the transaction. The latest version of Incoterms rules were revised in 2010, so called Incoterms$^{(R)}$ 2010 which is the eighth set of pre-defined commercial terms published by the International Chamber of Commerce(ICC) in 1936. It has been already past 5 years since Incoterms$^{(R)}$ 2010 became effective January 1, 2011. At this point, we should examine the latest version of Incoterms whether the rules are not satisfied with the practical commerce because the customs and practices of commerce change constantly. The main purpose of this article is to seek a difference between the present commercial customs and practice and the rules of Incoterms$^{(R)}$ 2010. In addition, if there is any difference between them, an alternative resolution would be suggested. This article exercises the process of transition of the Incoterms rules, especially CIP, DDP, and CIF among 11 rules of Incoterms$^{(R)}$ 2010. Then this article provides some feasible alternatives to attempting to resolve some regulation problems of CIP, DDP, and CIF in the Incoterms$^{(R)}$ 2010. For examples, the practical meaning is different between "if customary or at the buyer's request" and "if agreed or customary" in CIF and CIP, especially a negotiable documentary being used. Furthermore, the interpretation of transfer of risks on the afloat goods in string sales in CIF term.

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