• Title/Summary/Keyword: Dry method

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The Study on the Compaction Characteristics of Underground Structural Backfill with Reclaimed Soil (준설토를 이용한 지하구조물 뒷채움 다짐특성에 관한 연구)

  • 김영웅;박기순;손형호;김종국
    • Proceedings of the Korean Geotechical Society Conference
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    • 1999.03a
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    • pp.357-364
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    • 1999
  • The purpose of this study is to analysis the grain distribution and compaction characteristics of structural backfill with reclaimed soil. Five(5) reclaimed soil samples which passed #200 sieve have been used in the test. The study showed that the maximum dry density and the bearing value rate turned out to be becoming smaller when the more the quantity passed #200 sieve, the smaller the soil grain. The maximum dry density value calculated from the compaction md relative density test showed wet method > compaction method > dry method. The correlation coefficient between Rc and Dr based on the grain distribution and the compaction characteristics showed that the maximum dry density value by the wet method is little higher than the compaction method and dry method.

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A Study on the Measurement of Water Content in Hydrogel Contact Lens by Gravimetric Method (중량측정법에 의한 하이드로젤 콘택트렌즈의 함수율 측정에 관한 연구)

  • Kim, Tae-Hun;Ye, Ki-Hun;Sung, A-Young
    • Journal of Korean Ophthalmic Optics Society
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    • v.13 no.4
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    • pp.59-63
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    • 2008
  • Purpose: The purpose of this study is to understand a relation of water content measurement with two different method, water removal method and dry method. Methods: 72 hydrogel contact lens containing various water content (ranged from 47% to 58%) were measured by the gravimetric method at 20$^{\circ}C$and 21% of the humidity. We weighed the dried test specimen at room temperature for 30 min after cooling. Results: In dry blotting method, the water content was measured to 47.43${\pm}$8.48%. The water contents was measured to 48.15${\pm}$8.36% with wet blotting condition. It was found that wet blotting method showed the higher water content of about 7% than dry blotting method. In water content with two dry methods, each of results was measured by 47.89${\pm}$8.06% and 49.56${\pm}$7.06%. In case of microwave method, the water content was measured significantly higher water content of about 1.67% than vacuum oven method. However, no statistical difference was found (p>0.05). Conclusions: In water removal method (Dry blotting method and Wet blotting method) to weigh hydrated test specimen, wet blotting method showed significantly higher water content than dry blotting method. Also in case of dry methods (vacuum oven and microwave) to weigh dry test specimen, water content of microwave method showed higher water content than vacuum oven method, but it should be noted that microwave oven method must be used carefully to measure accurateness on the specimen position and wave power.

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Influence of Dry Methods on Qualities of Artemisia sp. (쑥의 건조 방법에 따른 품질 변화)

  • Park, Sung-Ok;Kim, Choong-Ho
    • Culinary science and hospitality research
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    • v.12 no.3 s.30
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    • pp.108-118
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    • 2006
  • This study is on different dry methods for Artemisia sp. which were not affected by the dry matter percent. Essential oil components such as 1,8-cineol and terpineol were highly affected by the dry method. 1,8-cineol and terpineol components were decreased by adaptation of the heated oven-drying method and the freeze-drying method. Borneol components were increased through shady sun-drying, sun-drying and freeze-drying. Heated oven drying method decreased the vitamin C content. Vitamin C content was decreased in oven-drying about 50% during this period, but only 10% decreased in the freezing dry method. Qualities were changed by different drying methods. Therefore, different dry methods of Artemisia sp. were applied to the flavorgen.

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Estimation of Dry Deposition Velocity for Elements in Atmospheric Aerosols by Low-Pressure Impactor (저압 임팩터를 이용한 대기 에어로졸 중 원소 성분의 건성침착속도 추정에 관한 연구)

  • 박정호;최금찬
    • Journal of Korean Society for Atmospheric Environment
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    • v.16 no.5
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    • pp.445-451
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    • 2000
  • To estimate dry deposition flux of 12 elements in aerosols, aerosol particles were sampled by a low-pressure impactor(LPI) and a dust jar. The concentrations of 12 elements in aerosol particle and dry deposition were analyzed by a PIXE analysis using as a 2.0 MeV-proton beam. The mean dry deposition velocities of 12 elements were estimated by ranges of 0.74∼2.62 cm/sec. The results showed that the highest value was 3.26 cm/sec for Ca and the lowest value 0.74 cm/sec for Fe. The dry deposition flux for elements was calculated as a function of particle size by 1-step method and 12-step method. In this work, dry deposition velocities were computed with the two existing models; the coarse-particle fraction(4∼30 mm diameter) using the dry deposition velocity model of the Noll and Fang(1998) and the fine-particle fraction (0.05∼4mm diameter) using the Shemel and Hodgson(1980) model. The ratios of the mean calculated/measured fluxes were 3.59 for 1-step method and 0.60 for 12-step method respectively.

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Development of Dry/Wet Algorithm for 2-Dimensional Flow Analysis (2차원 흐름해석을 위한 마름/젖음 알고리듬의 개발)

  • Kim, Sang-Ho;Han, Kun-Yeun;Choi, Seung-Yong;Oh, Hyun-Uk
    • Proceedings of the Korea Water Resources Association Conference
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    • 2008.05a
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    • pp.624-628
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    • 2008
  • Two-dimensional flow analysis is a way to provide good estimates for complex flow features in flow around islands and obstructions, flow at confluence and flow in braided channel. One of difficult problems to develop a two-dimensional hydraulic model is to analyze dry and wet area in river channel. Dry/wet problem can be encountered in river and coastal engineering problems, such as flood propagation, dam break analysis, tidal processes and so on. The objective of this study is to develop an accurate and robust two-dimensional finite element method with dry/wet technique in complex natural rivers. The dry/wet technique with Deforming Grid Method was developed in this study. The Deforming Grid Method was used to construct new mesh by eliminating of dry nodes and elements. The eliminated nodes and elements were decided by considering of the rising/descending velocity of water surface elevation. Several numerical simulations were carried out to examine the performance of the Deforming Grid Method for the purpose of validation and verification of the model in rectangular and trapezoidal channel with partly dry side. The application results of the model were displayed reasonable flow distribution.

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Feasibility Study of Dry Forming with Dry Forming Mould (원주형 건식초지기를 이용한 건식초지 가능성 평가)

  • Kim, Jong-Min;Lee, Hak-Lae
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.41 no.1
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    • pp.9-16
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    • 2009
  • Cylindrical dry forming mould was developed to carry out a feasibility study of dry forming of papers. The effect of disintegration, forming, humidification and pressing on dry formed papers was examined. Dry disintegrated fibers showed the similar fiber length distribution to wet disintegrated fibers, but they showed distorsion and damaged appearance on the surface. Process parameters required to form a uniform fiber pad was investigated. A proper screening and air dispersion method was selected that gives proper formation. Humidification and pressing conditions were examined to get a good dry formed papers in dry forming. Results showed that dry forming method can be used to make a sheets with reasonable formation and properties.

Dry Cleaning of Si Contact Hole using$UV/O_3$ Method ($UV/O_3$을 이용한 Si contact hole 건식세정에 관한 연구)

  • 최진식;고용득;구경완;김성일;천희곤
    • Electrical & Electronic Materials
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    • v.10 no.1
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    • pp.8-14
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    • 1997
  • The UV/O$_{3}$ dry cleaning has been well known in removing organic molecules. The UV/O$_{3}$ dry cleaning method was performed to clean the Si wafer surfaces and contact holes contaminated by organic molecules such as residual PR. During the cleaning process, the Si surfaces were analyzed with X-ray photoelectron spectroscopy (XPS), atomic force microscope (AFM) and ellipsometer. When the UV/O$_{3}$ dry cleaning at 200'C was performed for 3 minutes, the residual photoresist was almost removed on Si wafer surfaces, but Si surfaces were oxidized. For UV/O$_{3}$ application of contact hole cleaning, the contact string were formed using the equipment of ISRC (Inter-university Semiconductor Research Center). Before Al deposition, UV/O$_{3}$ (at 200.deg. C) dry cleaning was performed for 3 minutes. After metal annealing, the specific contact resistivity was measured. Because UV/O$_{3}$ dry cleaning removed organic contaminants in contact holes, the specific contact resistivity decreased. Each contact hole size was different, but the specific contact resistivities were all much the same. Thus, it is expected that the UV/O$_{3}$ dry cleaning method will be useful method of removal of the organic contaminants at smaller contact hole cleaning.

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Drill Shape and Cutting Conditions for Environmentally Conscious Drilling (환경친화적 건식 드릴링을 위한 드릴형상 및 절삭조건)

  • 고태조
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.9 no.2
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    • pp.36-44
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    • 2000
  • In this paper drill shape and cutting conditions for environmentally conscious dry drilling of A319 Al-alloy are studied by experimental method. The experiment is planned with Taguchi's method that is based on the orthogonal array of design factors. The result is summarized as follows (1) Drill geometry optimization can increase the number of holes in dry drilling and also large helix angle and large point angle are desirable in dry drilling. (2) It is found that cutting conditions that is cutting speed and feed rate are closely related to the drill geometry(3) For dry drilling of Al-alloys drill shape and cutting conditions are selected and tested by experimental method. But it is found that the perfect dry drilling is difficult because of the machining characteristics of Al-alloys and so new machining method such as minimal lubricant application is required.

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Preparation of High Permeability Mn-Zn Ferrites by the Wet Method (습식법에 의한 고투자율 Mn-Zn Ferrite의 제조에 관한 연구)

  • 이경희;이병하;허원도;황우연
    • Journal of the Korean Ceramic Society
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    • v.31 no.1
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    • pp.55-61
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    • 1994
  • Mn-Zn ferrite powder was obtained by wet method that was to be coprecipitated the metal ions of Fe2+, Mn2+ and Zn2+ with alkali solution. The target composition of the ferrite powder was 52 mol% Fe2O3, 24 mol% MnO, and 24 mol% ZnO, that was based on the region of high permeability. And the other ferrite powder was prepared by the dry method that was to be mixed the metal oxides as the above chemical composition. The wet method was compared with dry method for the powder properties and the electromagnetic characteristics of sintered cores. The synthesized powder by wet method was smaller particle size, narrower particle distribution, and higher purity than that of dry method. The initial permeability of sintered sample prepared by the wet method was 14000~28000, on the other side, 9000~15500 in case of the dry method.

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Evaluation of dry feeding and liquid feeding to lactating sows under high temperature environment

  • Hong, J.S.;Jin, S.S.;Jung, S.W.;Fang, L.H.;Kim, Y.Y.
    • Journal of Animal Science and Technology
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    • v.58 no.10
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    • pp.36.1-36.5
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    • 2016
  • Background: Liquid feeding system has been introduced to domestic swine farms, but negative cognition about liquid feeding system has been remained for feed waste decay related with poor management and microbial contamination. For these reasons, this study was conducted to evaluate the effects of feeding method in lactating sows. Methods: A total of 30 mixed-parity (average 4.13) lactating sows (Yorkshire ${\times}$ Landrace) with an initial BW of $218.8{\pm}19.5kg$ was used in a 3 week trial. Sows were allotted to 1 of 2 treatments in a completely randomized design by their body weight, backfat thickness, parity and alive litter weight. One of treatments was dry feeding and the other was liquid feeding (water to feed ratio, 1:1). Experimental diets contained 3265 kcal ME/kg, 12.6 % CP, 5.76 % EE, 1.09 % total lysine, 0.25 % total methionine, as fed basis. Results: Dry feeding treatment had high body weight loss rather than liquid feeding treatment (P = 0.04). Dry feeding treatment had tendency to increase litter weight at 21d of lactation (P = 0.06) and litter weight gain (P = 0.04) during lactation period (0-3 week). Sows fed dry feeding method made milk containing high content of casein and total solid rather than sows fed liquid feeding method (P = 0.04). In addition, dry feeding treatment had tendency to higher content of milk fat, protein and solid not fat on 21d of lactation (P = 0.07). Sows fed dry feeding type also showed higher milk energy content in milk of 21d lactation (P = 0.05). Furthermore, liquid feeding treatment showed high occurrence in feed waste during lactation period (P <0.01). Conclusion: Dry feeding method was more suitable feeding method to lactating sows under high temperature environment like lactating barn.