• Title/Summary/Keyword: Mixed load

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Repair and Rehabilitation of Polymer-Steel Fibrous High Strength Concrete Beams (폴리머-강섬유를 혼입한 고강도 콘크리트 보의 보수·보강)

  • Kwak, Kae-Hwan;Kim, Won-Tae
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.6 no.2
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    • pp.135-143
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    • 2002
  • This study is to investigate its use by applying stainless steel wire mash reinforcement method of construction, which is newly developed, on the high strength concrete beam mixed with polymer-steel fiber. In this test, it is investigated and observed such as follows: the ultimate load, the initial flexure crack load, the initial diagonal tension crack load, the relation between load and deflection, load-strain relation, and also crack growth and fracture aspect by increasing load. The results of this test are; first, the stainless steel wire showed some useful reinforcement effects in multiplying the steel's resisting force of moment to the tensile force of beam or slab: second, the promoting strength and internal force was made in the process of the integration at the same reaction by using the penetrating polymer-mortar with an excellent durability and physical property. On the basis of this results, because such instances in applying stainless steel wire Mash reinforcement method of construction have been few so far, through the experimental investigation such as this test over and over again, the efficient and useful method must be developed for the practice.

Comparative Analysis of Voltage Unbalance Factor on the use of Linear and Non-linear loads in Three-phase Four-wire Low Voltage Distribution Line (3상 4선식 저압 배전선로에서 선형 및 비선형 부하의 사용시 전압 불평형률 비교 분석)

  • Kim, Jong-Gyeum;Kim, Ji-Myeong
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.3
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    • pp.587-592
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    • 2017
  • In the three-phase four-wire low-voltage power distribution equipment, single-phase and three-phase load have been used mainly mixed. Also linear and nonlinear loads have been used together in the same conditions. In a three-phase four-wire distribution line, the current distribution of three-phase linear load is almost constant in each phase during driving or stopping, but the single-phase load is different from each other for each phase in accordance with the operation and stop. So that the voltage unbalance is caused by the current difference of each phase. In the three-phase four-wire distribution system, non-linear load is used with linear load. The presence of single-phase nonlinear loads can produce an increase in harmonic currents in three-phase and neutral line. It can also cause voltage unbalance. In the present study, we analyzed for the voltage unbalance fluctuations by the operation pattern of the single and three-phase linear and non-linear load in three-phase four-wire low voltage distribution system.

Mixed Mode Crack Propagation using the High Strength Concrete Disk (고강도 콘크리트 디스크를 이용한 혼합모드 균열전파)

  • 진치섭;김희성;박현재;김민철
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10a
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    • pp.733-738
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    • 2000
  • It is difficult to obtain accurate fracture toughness values by RILEM committees proposed three point bend test(TPB) because the shape of load-deflection curve is irregular and final crack propagation occurs after some slow stable cracking. However, for disk test, fracture toughness is easily obtained from crack initial load. We examined the cracked high strength concrete disk and the experimental results were compared with the results by finite element analysis(FEA). Also we compared experimental fracture locus with theoretical fracture locus.

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Effect of nutrient composition in a mixed meal on the postprandial glycemic response in healthy people: a preliminary study

  • Kim, Jiyoung S.;Nam, Kisun;Chung, Sang-Jin
    • Nutrition Research and Practice
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    • v.13 no.2
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    • pp.126-133
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    • 2019
  • BACKGROUND/OBJECTIVES: The glycemic index (GI) is a measure of the postprandial glucose response (PPGR) to food items, and glycemic load (GL) is a measure of the PPGR to the diet. For those who need to maintain a healthy diet, it is beneficial to regulate appropriate levels of blood glucose. In reality, what influences the meal GI or GL depends on the macronutrient composition and the physical chemistry reactions in vivo. Thus, we investigated whether different macronutrients in a meal significantly affect the PPGR and the validity of calculated GI and GL values for mixed meals. SUBJECTS/METHODS: 12 healthy subjects (6 male, 6 female) were recruited at a campus setting, and subjects consumed a total of 6 test meals one by one, each morning between 8:00 and 8:30 am after 12 h of fasting. PPGR was measured after each consumed meal and serial finger pricks were performed at indicated times. Test meals included 1) 68 g oral glucose, 2) 210 g rice, 3) rice plus 170 g egg white (RE), 4) rice plus 200 g bean sprouts (RS), 5) rice plus 10 g oil (RO), and 6) rice plus, egg white, bean sprouts, and oil (RESO). The incremental area under the curve (iAUC) was calculated to assess the PPGR. Mixed meal GI and GL values were calculated based on the nutrients the subjects consumed in each of the test meals. RESULTS: The iAUC for all meals containing two macronutrients (RS, RO, or RE) were not significantly different from the rice iAUC, whereas, the RESO iAUC ($2,237.5{\pm}264.9$) was significantly lower (P < 0.05). The RESO meal's calculated GI and GL values were different from the actual GI and GL values measured from the study subjects (P < 0.05). CONCLUSIONS: The mixed meal containing three macronutrients (RESO) decreased the PPGR in healthy individuals, leading to significantly lower actual GI and GL values than those derived by nutrient-based calculations. Thus, consuming various macronutrient containing meals is beneficial in regulating PPGR.

A Study on the Vibration Characteristics of Collecting Plate in the Electrostatic Precipitator Using Holograpy (홀로그래피를 이용한 정전집진기 집진판의 진동 특성 연구)

  • 나종문;이기백;양장식
    • Journal of Advanced Marine Engineering and Technology
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    • v.20 no.1
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    • pp.56-66
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    • 1996
  • In this study, the characteristics of generation and propagarion of transient wave induced in the assembly of four collecting plate upon the propagation of waves are analyzed. Also double exposure holographic inteferometry using ruby pulse laser is built in order to investigate the propagation of transient waves generated by impact load. When impact load was applied at edge of connecting band, the vibration of collecting plates was generated from the contact points between collecting plate and band which connects four collecting plates. Waves generated from the lower part and those reflected from the upper part were mixed as time went on and then formed very complex shapes. Also, when impact load was aplied at center of collecting plate, the waves propagating across the convexo-concave plane were reflected partly at curved section. Therefore the vibration amplitude was decreased as the transiet waves were propagated through the convexo-concave plane.

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A Study for the Performance Improvement by Fumigation LPG on Diesel Engine using a Used Frying Oil (폐식용유를 사용한 디젤기관에서의 LPG 공급에 의한 성능개선에 관한 연구)

  • 조기현;황의현;백태실;정형길
    • Journal of Advanced Marine Engineering and Technology
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    • v.24 no.5
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    • pp.16-24
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    • 2000
  • In this study, using frying oil, performance of engine and emission concentration were compared with the case of using diesel oil. And results are as follows. 1. Engine torque and brake horse power indicate nearly same value as the case of using diesel fuel. 2. Temperature of exhaust gas was increased with as high engine speed and load. 3. To reduce concentration of hydrocarbon, it is effective to operate using used frying oil in low engine speed and load, and adding LPG in high engine speed and load. 4. Concerning with concentration of carbon mono oxide and smoke emission, it was assured, that as engine load increased, lower concentration emitted in case of utilizing mixed fuel than that of utilizing pure diesel fuel.

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An Allocation Strategy for Direct Load Control Program Resources in Power Systems (전력계통운전상황을 고려한 직접부하제어자원의 배분전략)

  • Cho, K.S.;Lee, C.J.;Park, J.B.;Shin, J.R.;Kim, H.C.
    • Proceedings of the KIEE Conference
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    • 2003.11a
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    • pp.444-446
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    • 2003
  • This paper deals with an allocation strategy for the resources of direct load control program, which is considered the operating states in power systems. The existing approaches, load shedding priority algorithm, curtailment payback based algorithm and mixed curtailment algorithm, are based on the uniform allocation strategy. These approaches are not taken into account the operating states in power systems. So, under the critical operating condition, direct load control resource is evaluated by introducing the congestion factor.

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A Study on the Estimation of Zoysia matrella's Evaporation Using Makkink Model (인공지반에서 금잔디의 증발산량 예측에 관한 연구 -퍼라이트 배합토에서 Makkink의 일사법을 이용하여-)

  • 김도경;황지환
    • Journal of the Korean Institute of Landscape Architecture
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    • v.29 no.1
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    • pp.161-167
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    • 2001
  • The purpose of this study is to find out the difference of Zoysia matrella's evaporation in between 100 percent soil and mixed soil with 50 percent of perlite to create green spaces on the artificial ground. It is believed that the weight against the artificial ground will be reduced, provided the vegetation is possible in the circumstance of the mixed sol with 50 percent of perlite. The study employed a modified Makkink's model by Iwasa who had developed the model for estimating Zoysia matrella's evaporation in the natural ground using the Makkink's formula in 1997 at Chiba University, Japan. The parameter of Makkink's formula is the solar radiation. For that reason, the Makkink's formula is simple and easy to measure the parameter and has a high utility. If the outcomes from mixed soil are close to modified Makkinks formula, the modified Makkink's formula will be applied to estimate in the artificial ground with mixed soil with 50 percent of perlite. Weather observation and actual amount of evaporation of Zoysia matrella have been measured, and the relation between weather condition and actual amount of evaporation had been also investigated. In line with this, we found out that there is a relevant relationship between daily average temperature, the modified Makkink's model by Iwasa, and the actual amount of evaporation. As the results of the experiment, the outcomes from mixed soil with 50 percent of perlite have very high relation to 100 percent soil. In addition, mixed soil has more adhesion with water than natural soil. However, it needs to be adequately maintained in terms of fertilization and damage from disease and harmful insects until the gras fastens its roots into the soil. By using mixed soil with 50 percent of perlite, the load from soil on the artificial ground can be reduced. The study on the growth of the grass throughout the plant vegetation and the actual amount of evaporation in the mixed soil with 50 percent of perlite should be performed in the future.

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An Analysis of Factors Affecting Environmental Load in Earthwork Type of Road Project (도로건설공사 토공작업부에 대한 환경부하 영향인자 분석)

  • Park, Jin-Young;Im, Je-Gyu;Kim, Byung-Soo
    • Korean Journal of Construction Engineering and Management
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    • v.19 no.4
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    • pp.52-60
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    • 2018
  • In the construction industry, attempts to evaluate the environmental impact of products through life cycle assessment (LCA) approach has been on the rise. However, the domestic construction industry needs to make rapid decisions due to limited budget and schedule, so it is difficult to carry out a review of the environmental load on all resources. The decision-making process requires information on the major influence factors that should be focused on to reduce environmental load. And this information should be quantified so that it can be linked to environmental impact assessment. In this study, the LCA results of road construction cases were analyzed to provide such information. As a result, diesel, ready-mixed concrete, urethane-based paint, aggregate, and asphalt concrete were found to be the main factors that generated 93.17% of the environmental load in the earthwork type of road project. The total environmental cost caused by these affecting factors when constructing 1 km of earthwork type of road project is 242 million won. The analysis also shows that a 10% reduction in the amount of ready-mixed and asphalt concretes can reduce carbon emissions by 5.02% and 2.28% while reducing environmental costs by 11 million won per kilometer. In order to reduce carbon emissions of the earthwork type of road project, it is necessary to actively develop and introduce new methods and eco-friendly materials to reduce the overall use of ready-mixed concrete and asphalt concrete.

Structural Behavior of Holed RC Beam mixed with Sawdust (폐톱밥 혼입 RC 유공보의 구조거동에 관한 실험적 연구)

  • Son, Ki-Sang;Lee, Jae-Hyeong
    • Journal of the Korean Society of Safety
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    • v.21 no.1 s.73
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    • pp.96-104
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    • 2006
  • This study is to find out how the sawdust-mixed RC beam with holes acts compared to two case of normal one with sawdust without hole, without sawdust. variables are ED3H1, ED3H2, ED3H1UB, ED3H2L, ED5H1, ED5H1UB, ED5H2, ED5H2L, Normal with sawdust PLA without sawdust. All sand, aggregate, cement are in accordance with KS. mixing design is also in accordance with KS and done at D remicon company in order to decrease any error in mixing manually. ED3H1 showed 7tone of maximum load capacity having only minor tensile deformation around hole, compared to the center of the beam. ED5H2L showed almost same shape of tensile strain between hole area and center of two beam length, while having 9.5 tone load capacity, incase of two holes being in the longitudinal axis. But ED5H2 in case of two holes being in same forcing direction showed 8.4tone of load capacity while having minor tensile chape around hole and normal tensile shape in the center of beam length. Two diameter 3cm hole in longitudinal axis give more effective behavior than the other case, practically. Capacity decrease between 5cm and 3cm in eccentric position form the longitudinal axis is less than percents. There is minor capacity difference between hole diameter 3cm hole, but 13tone difference of load capacity between hole diameter 5cm.