• Title/Summary/Keyword: wet-dry

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Measurement of GPR Direct Wave Velocity by f-k Analysis and Determination of Dielectric Property by Dispersive Guided Wave (f-k 분석에 의한 레이다파 속도 측정 및 레이다파의 분산성 가이드 현상을 이용한 지하 물성 계산)

  • Yi, Myeong-Jong;Endres, Anthony L.;Kim, Jung-Ho
    • Geophysics and Geophysical Exploration
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    • v.9 no.4
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    • pp.304-315
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    • 2006
  • We have examined the applicability of f-k analysis to the GPR direct wave measurement for water content to characterize vadose zone condition. When the vadose zone consists of a dry surface layer over wet substratum, we obtained f-k spectra where most of the energy is bounded by the air and dry soil velocities. In this case, dry soil velocity was successfully estimated by using high frequency data. On the other hands, when wet soil overlies dry substratum, the f-k spectra show a contrasting response where most of the energy travels with the velocity bounded by dry and wet soil velocities. In this case, the radar waves are trapped and guided within wet soil layer, exhibiting velocity dispersion. By adopting modal propagation theory, we could formulae a simple inversion code to find two layer's dielectric constants as well as layer thickness. By inverting the velocity dispersion curve obtained from f-k spectra of synthetic modeling data, we could obtain good estimates of dielectric constants of each layer as well as first layer thickness. Moreover, we could obtain more accurate results by including the higher mode data. We expect this method will be useful to get the quantitative property of real subsurface when the field condition is similar.

Experimental Study on Reduced Amount of Rebound in Wet Process Shotcrete Works by Upon Accelerator Contents (급결제 함유량에 따른 습식 Shotcrete 리바운드 감소량에 대한 실험적 연구)

  • Jeon, Jun Tai;Park, Hong Tae;Lee, Yang Kyu
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.32 no.6D
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    • pp.615-622
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    • 2012
  • The aim of shotcrete is to increase the bearing capacity and to protect the excavated surface from erosion by preventing falling of rock mass. Shotcreting method is divided into two types as dry process and wet process. Since 1997, wet process method has been used more frequently than dry process method in field works. The failure to bond, so called rebound, occurs in many case during shotcrete works. The excess amount of rebound has a significant effect on the total construction cost. For example, material and craft-man cost increases, the shooting time delays due to deceleration of work execution stage, work efficiency of craft-man decreases and additional cost to remove the muck generates. In this study, therefore, the experimental analysis of rebound amount and strength was conducted by analyzing the actual construction data for wet process type of shotcreting method upon accelerator contents. Also, the effective and rational method was suggested, which can be actually implemented in the Korea construction sites.

Analysis of the Dry disease of Yuchang's "Autumn dry theory" (유창(喩昌)의 "추조론(秋燥論)"의 조병(燥病)에 대한 내용 분석)

  • Kim, Nam il
    • The Journal of Korean Medical History
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    • v.15 no.2
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    • pp.11-20
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    • 2002
  • In "EuiMoonBubRyool" chapter 4, Yuchang criticized previous doctors since "damaged by wet in autumn" written in "Somun" must be corrected as "damaged by dry in autumn". The reason why the sentence must be corrected is that dry and damp are different atmosphere. He tried to explain with changes of season and the rapid pulse in autumn is said to be a contraindiction in "Naekyung" and it supports Autumn dry theory. He criticized previous doctors about many incorrect points of dry disease throu호 various aspects. Criticism on Dongwon's treatment, Dangye's medical theory and not having a treatment, and Mujungsoon's treatment and etc. are the examples. Symtoms and treatment of Dry disease that Yuchang commented helped in deepening the contents and widening the general understanding of the disease.

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Study on the Humidity Effect on Gas turbine Engine Performances (습도가 엔진성능에 미치는 영향에 대한 실험적 고찰)

  • Lee, Bo-Hwa;Lee, Kyung-Jae;Yang, Soo-Seok;Kim, Chun-Taek
    • Aerospace Engineering and Technology
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    • v.9 no.2
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    • pp.98-104
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    • 2010
  • The moisture in the atmosphere exerts a lot of influence upon Gas turbine engine performances. There is a noticeable influence of wet air at the summer sea level, high flight mach number and low engine rpm increasingly. An altitude Engine Test Facility is used to accomplish the engine performance tests at dry air condition and wet air condition, through which engine performance results is revealed. Also, Gas turbine Simulation Program is used to predict the variation of engine performance due to inlet humidity. In the result, net thrust and specific fuel consumption measured -2.826% and 1.325%, respectively at wet air condition compared to dry air condition.

Effects of Lift Resistance on Dynamic Load Acting on a Circular Wheel

  • Kishimoto, Tadashi;Taniguchi, Tetsuji;Sakai, Jun;Choe, Jung-Seob;Ohtomo, Koh-Ichi
    • Proceedings of the Korean Society for Agricultural Machinery Conference
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    • 1993.10a
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    • pp.1166-1175
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    • 1993
  • The objective of this study is to measure contra-retractive adhesion and lift resistance acting on the rim section of a circular wheel for analyses of their effects on the dynamic load. A circular iron wheel was used for experiments. A part of the wheel rim was cut off, and transducers which can measure normal and tangential forces were installed in this section. Experiments were conducted on a laboratory soil bin which was filled with clayey soil under wet and dry conditions. The mechanism of generating contra -retractive adhesion on a circular wheel were analyzed by the experiments and motion analyses of the wheel. Effects of lift resistance on dynamic load were analyzed by measured forces under wet soil conditions in comparison in comparison with those under dry conditions. The showed that a part of the lift resistance were transferred to the dynamic load. These results may become basic data and ideas for analyses of tractor dynamic under wet soil conditions.

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Study of Stabilizing 5,6-dihydroxyindole with Coating Process Against Oxidation and Light (코팅프로세스를 사용한 5,6-디하이드록시인돌의 산화 및 광에 대한 안정화 연구)

  • Han, Sang-Keun;Lee, Dong-Kyu
    • Journal of the Korean Applied Science and Technology
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    • v.30 no.3
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    • pp.518-527
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    • 2013
  • 5,6-dihydroxyindole was easily oxidation with air and light Conditions. Availability of 5,6-dihydroxyindole was studied for hair dye as a precursor of melanin. This study used wet and dry coating process to stabilize 5,6-dihydroxyindole. In wet process used dimethicone and cyclometicone, the 5,6-dihydroxyindole had darkened through the drying process at $58^{\circ}C$. Wet coating process was inappropriate to stabilize the coating. In dry coating process, shea butter coating was stable until 3 days. Dextrin palmitate was most efficient ingredient to prevent oxidation by sun light and air until 7days. Oxidation test with 1.0% and 1.5% of dextrin palmitate was not different under conditions of sun light and air and was not dependent on contents. Vitamin E acetate under conditions of sun light and air, there were no significant effect in preventing oxidation.

Genetic Variation in Growth and Body Dimensions of Jersey and Limousin Cross Cattle. 2. Post-Weaning Dry and Wet Season Performance

  • Afolayan, R.A.;Pitchford, W.S.;Weatherly, A.W.;Bottema, C.D.K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.10
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    • pp.1378-1385
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    • 2002
  • The importance of direct genetic, maternal, heterosis and epistatic effects were examined on post-weaning weight, height, length, girth, fat depth and muscle (ratio of stifle to hip width) with dry and wet season gains in these traits. The breeds used were two pure breeds (Jersey and Limousin), the Limousin${\times}$Jersey $F_1$, and two backcrosses ($F_1{\times}$Jersey dams and $F_1{\times}$Limousin dams). Direct genetic effects were large (p<0.001) for all traits except for length. Jersey maternal effects were large for weight, girth, fat depth and muscle in the post-weaning wet season gains which is an evidence of the impact of Jersey dam on progeny beyond weaning. There were large heterosis effects on fat depth and muscle relative to other traits. Epistatic effects were observed for post-weaning performance in weight, girth, fat depth and muscle. There are indications that there were different genetic effects for post-weaning compared to preweaning growth traits. Thus, it could be hypothesized from this study that different quantitative trait loci (QTL) affect early and late growth in Jersey and Limousin cross cattle breeds. The follow up work will examine the different chromosomal gene effects on pre- and post-weaning growth.

Effect of inlet structure of filtration system on the removal characteristics of iron particles by ceramic candle filters (집진장치의 유입구조에 따른 세라믹필터의 철입자 제거특성에 미치는 영향)

  • Park, Young-Ok;Jeong, Ju-Yeong;Seo, Yong-Chil
    • Particle and aerosol research
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    • v.5 no.4
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    • pp.189-197
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    • 2009
  • Wet-type particulate removal system is employed in most of ironmaking processes. These de-dusting systems require additional downstream aggregates for treatment of water and for drying of the collected slurry. Thus dried slurry can be pressed in shape of briquettes and recycled in the steelmaking process. Different from the wet-type, the dry-type particulate removal systems generate no slurry. A high-temperature, high-pressure de-dusting system with inertial inlet was developed. The target application of this system was to remove particulate matter generated from the novel ironmaking process and other steelmaking processes. In this study we conducted tests with this newly developed system to evaluate the performance of the silica-carbide (SiC) ceramic filters. In addition, for purpose of comparison, we also conducted tests with a unit which has conventional direct inlet. Fe-Particles collected from the novel ironmaking process were used in our tests as test dusts. The temperature and the pressure were kept constant at their respective values $800^{\circ}C$ and $3kg_f/cm^2$.

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The introduction of Engine Performance Test for Miniature Turbojet Engine considering humidity effects (습도 영향을 고려한 초소형 터보제트 엔진 성능시험 소개)

  • Lee, Bo-Hwa;Lee, Kyung-Jae;Yang, Soo-Seok;Kim, Yu-Il
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2010.11a
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    • pp.335-338
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    • 2010
  • The moisture in the atmosphere exerts a lot of influence upon Gas turbine engine performances. There is a noticeable influence of wet air at the summer sea level, high flight mach number and low engine rpm increasingly. An altitude Engine Test Facility is used to accomplish the engine performance tests at dry air condition and wet air condition, through which engine performance results is revealed. In the result, net thrust and specific fuel consumption measured -2.826% and 1.325%, respectively at wet air condition compared to dry air condition.

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Evaluation of Machinability by various cutting conditions in high machining using ball nose-end mills -Effects of cutting orientation and cutting environments- (볼엔드밀을 이용한 고속가공에서 가공경로와 가공환경에 따른 가공성 평가)

  • 이채문;김석원;이득우
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2002.10a
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    • pp.297-301
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    • 2002
  • High-speed machining generates concenter thermal/frictional damage at the cutting ed rapidly decreases the tool life. This paper I at determining the effect of cutter orienter the cutting environment on tool life, tool mechanism when down milling. In this paper, experiments were carried out in various tool and cutting environments, such as dry, wet compressed chilled air, tool life were measu evaluate machinability in high-speed milli difficult-to-cut material and die steel, Tool measured in horizontal upwards, horiz downwards, vertical upwards and vert downwards. In addition, tool life was measur dry, wet and compressed chilled air. For this a compressed chi1led-air system was manufact The results show that a horizontal cutter ori provided a longer tool life than a vertical orientation. With respect to the cutting envi compressed chilled air increased tool life. H the wet condition decreased tool life due thermal shock caused by excessive cooling high-speed mill ins and the compressed chilled had little effect.

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