• Title/Summary/Keyword: High-volume

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A Study on Soot Formation of Turbulent Premixed Propane Flames in n Constant-Volume Combustor at High Temperatures and High Pressures (고온ㆍ고압 정적 연소기내 난류 프로판 예혼합 화염의 매연생성에 관한 연구)

  • 배명환
    • Transactions of the Korean Society of Automotive Engineers
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    • v.9 no.4
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    • pp.1-9
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    • 2001
  • The soot yield has been studied by a premixed propane-oxygen-inert gas combustion in a specially designed disk-type constant-volume combustion chamber to investigate the effects of pressure, temperature and turbulence on soot formation. Premixtures are simultaneously ignited by eight spark plugs located on the circumference of chamber at 45 degree intervals in order to observe the soot formation under high pressures. The eight flames converged compress the end gases to a high pressure. The laser schlieren and direct flame photographs for observation field with 10 mm in diameter are taken to examine into the behaviors of flame front and gas flow in laminar and turbulent combustion. The soot volume fraction in the chamber center during the final stage of combustion at the highest pressure is measured by the in situ laser extinction technique and simultaneously the corresponding burnt gas temperature by the two-color pyrometry method. The pressure and temperature during soot formation are changed by varying the initial charge pressure and the volume fraction of inert gas compositions, respectively. It is found that the soot yield increases with dropping temperature and rising pressure at constant equivalence ratio, and that the soot yield of turbulent combustion decreases in comparison with that of laminar combustion because the burnt gas temperature increases with the drop of heat loss.

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The Experience Study on the Floating Properties of High Flow Concrete on volum of Coarse Aggregate used Admixture (굵은골재 체적에 따른 고유동콘크리트의 유동특성에 관한 실험적 연구)

  • Choi, Sung-Woo;Kim, Ho-So;Baek, Chul-Woo;Ban, Seong-Soo;Ryu, Deuk-Hyun
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.751-754
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    • 2004
  • There are many factors that affect on the flowing properties of high flowing concrete(HFC), which are fluidity, compactibility, non-segregation ability and fillingability. And because the aggregate which is one of the factors occupies high volume in concrete, it has a much effect on the properties of high flowing concrete according to its size, quality and quantity etc. This is an experimental study to analyze the effect of admixture and volume of coarse aggregate in concrete on the flowing properties of high flowing concrete. For this purpose, the kinds of admixture are fly-ash and blast furnace slag. Also volume of coarse aggregate in concrete are 280, 290, 300, 310, 320 $(\ell/m^3)$. The test of flowablity properties is slump-flow, Air content, V-lot, L-Flow. According to test results, it was found that the compactibility of HFC is more superior to use blast furnace slag than other, and according .to kind of admixture, most compatible volume of coarse are different. Also when used blast furnace slag, the volume of coarse are increased than used fly-ash.

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Difference in Volume Perception according to Cup Shape in Normal Weight and Overweight Female College Students (정상체중과 과체중 여대생을 대상으로 컵의 형태에 따른 인지량의 차이에 관한 연구)

  • Lee, Myung-Ok;Chang, Un-Jae
    • Journal of the Korean Dietetic Association
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    • v.20 no.1
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    • pp.63-69
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    • 2014
  • The volume perception of water according to cup shape was examined in female college students divided into a normal weight group (<23 body mass index, n=51) and an overweight group (${\geq}$23 body mass index, n=48). The perceived water volume was recorded by participants after they observed the water volume in cups with different shape (highball and tumbler) and with different base height (high base and low base), which contained the same amount of water (150 ml). The normal weight group perceived a water volume of 238.5 ml (highball) and 201.6 ml (tumbler) for the high base cups. The overweight group perceived a volume of 245.6 ml (highball) and 188.8 ml (tumbler). For the low base cups, the normal weight group perceived a water volume of 207.8 ml (highball) and 104.1 ml (tumbler). The overweight group perceived a volume of 202.2 ml (highball) and 100.4 ml (tumbler). Both the normal weight and overweight groups perceived significantly more liquid in the highball cups compared to the tumbler cups. In addition, both groups perceived significantly more liquid in the high base cups compared to the low base cups. However, there were no significant differences in the estimated variance of perceived volume between the normal weight and overweight groups according to the cup shape and cup base height. In conclusion, cup shape and base height potentially affects volume perception. Therefore, modifying cup shape may be used in a weight control program to help control caloric beverage consumption.

Comparative Analysis of Forecasted and Measured Traffic Demand for Gyung-bu High Speed Railway (경부고속철도 수송수요의 예측치와 실측치의 비교분석)

  • Oh In-Tack
    • Proceedings of the KSR Conference
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    • 2005.11a
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    • pp.889-896
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    • 2005
  • While a year and a half has been passed since the launch of KTX service, traffic volume of Gyung-bu High Speed Railway is still much lower than the forecasted value. This situation has been badly affecting not only Korail's financial status but also KRNA's general railway construction projects as general public responds negatively to such projects as New Ho-nam Line Construction. This paper outlines traffic volume forecasting methodologies applied to construction of Gyung-bu High Speed Railway, identifies major causes of forecasting deviations. and finally extracts problems through comparison between the forecasted results and actual traffic volume.

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High-Volume Data Processing using Complex Event Processing Engine in the Web of Next Generation (차세대 웹 환경에서 Complex Event Processing 엔진을 이용한 대용량데이터 처리)

  • Kang, Man-Mo;Koo, Ra-Rok;Lee, Dong-Hyung
    • Journal of KIISE:Databases
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    • v.37 no.6
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    • pp.300-307
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    • 2010
  • According to growth of web, data processing technology is developing. In the Web of next generation, high-speed or high-volume data processing technologies for various wire-wireless users, USN and RFID are developing too. In this paper, we propose a high-volume data processing technology using Complex Event Processing(CEP) engine. CEP is the technology to process complex events. CEP Engine is the following characteristics. First it collects a high-volume event(data). Secondly it analyses events. Finally it lets event connect to new actions. In other words, CEP engine collects, analyses, filters high-volume events. Also it extracts events using pattern-matching for registered events and new events. As the results extracted. We use it by an input event of other work, real-time response for demanded event and can trigger to database for only valid data.

An Experimental Study on the Fluidity Properties of High Flowing Concrete Affected by Size and Volume Ratio of Coarse Aggregate (조골재 크기 및 용적비에 의한 고유동콘크리트의 각종 유동특성에 관한 실험적 연구)

  • 최세진;김완영;김진만;김무한
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10a
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    • pp.258-261
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    • 1998
  • Aggregate is cheaper than cement and confers considerable technical advantages on concrete, which has a higher volume stability and better durability than hydrated cement paste alone. and coarse aggregate is the largest particle size out of concrete and is much affect on the fruidity, compaction and non-segregation ability of high flowing concrete. As the compaction, fillingability and shrinkage of high flowing concrete, the volume ratio of coarse aggregate is prescribed by Japanese Architectural Standard Specificateon (JASS 5) : from 0.500 to 0.500㎥/㎥. It is the aim of this study to compare and analysis the fruidity, fillingability and non-segregation of high flosing concrete according to the volume ratio of coarse aggregate of concrete(G/Glim).

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A Fundamental Study on the Mix Design in High Volume Fly-Ash Concrete (플라이애시를 대량 사용한 콘크리트의 배합설계를 위한 기초적 연구)

  • 심재형;김재환;최희용;강석표;최세진;김무한
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.05a
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    • pp.641-646
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    • 2001
  • Generally, when Fly-Ash was used as replacement material of cement in concrete, it might occur retardation of setting and hardening. So, it is unable to use a large amount of Fly-Ash as replacement for cement. However, if it is used as replacement material of fine aggregate in concrete, we can use a large amount of Fly-Ash and settle a problem of natural-aggregate exhaustion. Furthermore, engineering properties of High Volume Fly-Ash Concrete Is better than that of plain concrete But, the larger Fly-Ash is replaced, the more fluidity of High Volume Fly-Ash Concrete decrease, because porous organization of Fly-Ash adsorb water and Superplasticizer. In this study, after appending additional water to High Volume Fly-Ash Concrete in proportion to weight of Fly-Ash, we intend to find proper ratio which doesn't affect strength and satisfy fluidity As a result of this study, it was found that fluidity of mortar with 25~28 percentage of additional water was satisfied with fluidity of plain mortar, and compressive strength of that was similar to plain mortar's

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Strength Properties by Curing Temperature of High Volume Fly-Ash Concrete (플라이애쉬를 다량 치환한 콘크리트의 양생온도에 따른 강도성상)

  • 이동하;정근호;백민수;김성식;임남기;정상진
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2002.11a
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    • pp.63-66
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    • 2002
  • In this study, it does a high volume flyash substituted concrete experiments in two curing temperature circumstances - 35$^{\circ}C$, 2$0^{\circ}C$. High volume flyash concrete is tested in fresh concrete properties and hardeded concrete properties. In the fresh concrete test items, there is slump, air contents, concrete setting tests. 3, 7, and 28 days water curing compressive strength is measured in the hardened concrete test. The purpose of this study is to submit a various flyash concrete data for application to field. The result of this study is that the best strength is developed at the plain concrete cured 2$0^{\circ}C$ and Mixing F43 shows the best strength among specimens which cured at 35$^{\circ}C$

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Mockup Test of the High Volume Blast Furnace Slag Concrete Using Recycled Aggregates and Incinerator Ash (순환골재 및 소각장 애시를 자극제로 사용한 고로슬래그 미분말 다량치환 콘크리트의 Mock-up 성능평가)

  • Kim, Young-Hee;Kwak, Yong-Jin;Kim, Jun-Ho;Lee, Hyang-Jae;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2012.11a
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    • pp.19-21
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    • 2012
  • This paper was to investigate the effect of incinerator ash on engineering properties of the high volume blast furnace slag concrete through Mock-up test. Test results revealed that the use of recycled aggregates resulted in increase of slump compared with the OPC concrete. But, the use of recycled aggregates did not affect the results of air contents and chloride contents. The use of recycled aggregates showed shortening of setting time of high volume blast furnace slag concrete. When the recycled aggregate was used, delay in strength development at early age happened with high volume blast furnace slag concrete compared with that of OPC concrete.

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Properties of the Combined High Flowing Concrete by Mix Design Factors (병용계 고유동 콘크리트의 배합요인에 따른 특성)

  • Kwon Yeong Ho;Lee Hyun Ho;Lee Hwa Jin;Ha Jae Dam
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.11a
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    • pp.407-410
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    • 2005
  • This research investigates experimentally an effect on the properties of the combined high flowing concrete by mix design factors. The purpose of this study is to determine the optimum mix proportion of the combined high flowing concrete having good flowability, viscosity, no-segregation and design strength(40.0MPa). For this purpose, trial mixings used belite cement+lime stone powder(LSP) are tested by mix design factors including water-cement ratio($47.9\~54.0\%$), fine aggregate volume ratio($41\~45\%$) and coarse aggregate volume ratio($41\~45\%$). As test results of this study, the optimum mix proportion for the combined high flowing concrete is as followings. Water-cement ratio $51.0\%$, fine aggregate volume ratio $43{\pm}1\%$ and coarse aggregate volume ratio $0.30{\pm}0.05m^3/m^3$ and replacement ratio of LSP $42.7\%$.

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