• Title/Summary/Keyword: Liquid back

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A Study on Refrigeration Performance of Vehicle HVAC System for Sub-Cooling Improvement (서브쿨링향상을 위한 차량공조 시스템의 냉방성능에 관한 연구)

  • 박만재
    • Transactions of the Korean Society of Automotive Engineers
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    • v.12 no.1
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    • pp.1-9
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    • 2004
  • The general method which changes sub-cooling of refrigerant is to control the expansion valve in the state of mixing with liquid and gas phase. In this study, the performance of vehicle air conditioning system is to control either changing the expansion valve or adding the sub condenser. Therefore, this research finally is tested in case of the fourth test procedure, the second test was suitable for a valve opening area due to adjusting valve slope in comparison with the other test. The other test except for the second test happened to do liquid back due to the excessively liquified refrigerant into the system. In conclusion, the second test was appeared not to be influenced upon liquid back, and it is to expect positive performance by controlling an expansion valve. Therefore, it will be also useful to research for an increase of compressor efficiency Performance improvement of an air conditioner is to reinforce the suction performance of the evaporator and increase the sub-cooling, which make use of the sub-cooling system.

A Study on the Visualization of Electrohydrodynamic Spray Flow in High DC Voltages (고전압 직류전기장에서 전기수력학적 분무 유동 가시화에 관한 연구)

  • Sung, K.A.
    • Journal of ILASS-Korea
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    • v.11 no.3
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    • pp.131-139
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    • 2006
  • An experimental study was performed to investigate the liquid breakup and atomization characteristics in electrohydrodynamic atomization according to the changing of experimental parameters such as nozzle size, fluid flow, and electrical intensity. An original electrohydrodynamic atomizer equipment was designed and manufactured for the analysis of spray visualization and the exploration of relationship between applied power and the behavior of liquid atomization. The image processing technique by using the back-illumination method was applied to visualize the distilled liquid breakup process and to examine the variation of the droplet size distribution. The results show that the spray modes of electrohydrodynamic atomization are closelyconnected by the strength of the electric stresses at the surface of the liquid film and the kinetic energy of the liquid jet leaving the needle tip.

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Back Light Unit using a Micro-lens Fabricated by the Modified LIGA Process (LIGA 방식을 적용시킨 Microlens 적용 Back Light Unit 개발)

  • Park, Jung-Ho;Sung, Ki-Sung;Yun, Suk-Joo;Ha, Soo-Yong;Lee, Kyu-Hyun;Hwang, Chul-Jin;Jeon, Suk-Hee
    • Proceedings of the Optical Society of Korea Conference
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    • 2004.07a
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    • pp.70-71
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    • 2004
  • Back light unit(BLU) using a microlens fabricated by the modified LIGA process for the liquid crystal display(LCD) is proposed, and some experimental results are presented. To realize the back light unit using microlens pattern, LIGA and reflow process are used.

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Experimental study on modified low liquid limit silt for abutment backfill in bridge-embankment transition section

  • Shu-jian Wang;Yong Sun;Zhen-bao Li;Kai Xiao;Wei Cui
    • Geomechanics and Engineering
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    • v.32 no.6
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    • pp.601-613
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    • 2023
  • Low liquid limit silt, widely distributed in the middle and down reaches of Yellow River, has the disadvantages of poor grading, less clay content and poor colloidal activity. It is very easy to cause vehicle jumping at the bridge-embankment transition section when the low liquid limit silt used as the backfill at the abutment back. In this paper, a series of laboratory tests were carried out to study the physical and mechanical properties of the low liquid limit silt used as back filling. Ground granulated blast furnace slag (GGBFS) was excited by active MgO and hydrated lime to solidify silt as abutment backfill. The optimum ratio of firming agent and the compaction and mechanical properties of reinforced soil were revealed through compaction test and unconfined compressive strength (UCS) test. Scanning electron microscope (SEM) test was used to study the pore characteristics and hydration products of reinforced soil. 6% hydrated lime and alkali activated slag were used to solidify silt and fill the model of subgrade respectively. The pavement settlement regulation and soil internal stress-strain regulation of subgrade with different materials under uniformly distributed load were studied by model experiment. The effect of alkali activated slag curing agent on curing silt was verified. The research results can provide technical support for highway construction in silt area of the Yellow River alluvial plain.

Design Using Bent Wood Plasticized with Liquid Ammonia (액체암모니아 휨가공 소재를 응용한 디자인)

  • 강호양;강형구
    • Journal of the Korea Furniture Society
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    • v.12 no.2
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    • pp.11-18
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    • 2001
  • Steaming has been used for bending wood for a long time, but the steam-bent wood is subject to spring-back and a relatively large radius of curvature. Liquid ammonia is known as an excellent wood plasticizer swelling both crystal and amorphous cellulose. Liquid ammonia technique for wood plasticization was developed and applied for bending alder and padauk pieces, which were used as parts of wooden furniture. The study confirmed that liquid ammonia bent wood can be used for various wood working design.

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The Electropalatographic Evidence of the Korean Flap: An Intervocalic Korean Liquid Sound

  • Ahn, Soo-Woong
    • Speech Sciences
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    • v.9 no.3
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    • pp.155-168
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    • 2002
  • The intervocalic Korean liquid sound has been recognized as a flap in the studies of the Korean language. But there has been very little experimental data corroborating it. The electropalatographic (EPG) experiment was conducted to test this. The subjects were one Korean speaker and one native English speaker who had a pseudopalate and did the EPG experiment at the UCLA phonetics laboratory. The spectrographic evidence of the flaps in both the English t-flap and the Korean liquid flap was also sought. The English and Korean flaps were between mid/low back vowels so that the vowels themselves would not affect palatal contacts of the tongue. The results confirmed that the Korean liquid is realized as a flap in intervocallical position with many similar properties to English flap in both EPG and spectrographic data. The Korean initial liquid sound in borrowed words such as 'rotary' and 'radio' was also a flap. But the Korean liquid in the word-final and geminate positions was a lateral as in words 'dol ' (stone), 'dollo' (with stone), 'nal' (day) and 'nallara' (carry). The intuitive theory of the Korean liquid flap was proved by the EPG and spectrographic data.

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Correlation of Liquid-Liquid Equilibrium of Four Binary Hydrocarbon-Water Systems, Using an Improved Artificial Neural Network Model

  • Lv, Hui-Chao;Shen, Yan-Hong
    • Journal of the Korean Chemical Society
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    • v.57 no.3
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    • pp.370-376
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    • 2013
  • A back propagation artificial neural network model with one hidden layer is established to correlate the liquid-liquid equilibrium data of hydrocarbon-water systems. The model has four inputs and two outputs. The network is systematically trained with 48 data points in the range of 283.15 to 405.37K. Statistical analyses show that the optimised neural network model can yield excellent agreement with experimental data(the average absolute deviations equal to 0.037% and 0.0012% for the correlated mole fractions of hydrocarbon in two coexisting liquid phases respectively). The comparison in terms of average absolute deviation between the correlated mole fractions for each binary system and literature results indicates that the artificial neural network model gives far better results. This study also shows that artificial neural network model could be developed for the phase equilibria for a family of hydrocarbon-water binaries.

Nutritional Approaches for Improving Neonatal Piglet Performance: Is There a Place for Liquid Diets in Commercial Production? - Review -

  • Odle, J.;Harrell, R.J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.11 no.6
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    • pp.774-780
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    • 1998
  • This report includes an extensive bibliography of research articles investigating various facets of rearing neonatal piglets using liquid diets, and includes historical publications dating back to the 1940's. However, in order to provide concise and timely focus for application in modem swine production, only a selected number of recent findings are reviewed in detail. Collectively, the data presented illustrate that growth of piglets fed liquid diets can greatly exceed that of littermates fed dry diets and can even exceed growth rates of sow-reared controls (by up to 160%). The central questions that remain unanswered are: 1) Can this improved performance be obtained routinely and economically under applied farm conditions? and if so, 2) Does improved growth during the early-weaning period translate into improved net economic returns overall? Unfortunately, due to the current practical management constraints related to liquid-diet feeding (i.e., lack of an easy-to-manage feed delivery system), limited data are available which examine the efficacy of liquid-diet feeding under practical, commercial farm conditions.

Spring Back in Amorphous Sheet Forming at High Temperature (아몰퍼스 고온 판재성형시 스프링백)

  • Lee Y-S
    • Transactions of Materials Processing
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    • v.14 no.9 s.81
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    • pp.751-755
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    • 2005
  • This paper is concerned with spring back after sheet forming of bulk amorphous alloys in the super cooled liquid state. The temperature-dependence and strain-rate dependence of Newtonian/non-Newtonian viscosities as well as the stress overshoot/undershoot behavior of amorphous alloys are reflected in the thermo-mechanical Finite Element simulations. Hemispherical deep drawing operations are simulated for various forming conditions such as punch velocity, die comer radius, friction, blank holder force, clearance and initial funning temperature. Here, spring back by an instantaneous elastic unloading was followed by thermal deformation during cooling, and two modes of spring back are examined in detail. It could be concluded that the superior sheet formability of an amorphous alloy can be obtained by taking the proper forming conditions for loading/unloading.