• 제목/요약/키워드: WET

검색결과 6,011건 처리시간 0.031초

실리콘 웨이퍼 습식 식각장치 설계 및 공정개발 (Design of Single-wafer Wet Etching Bath for Silicon Wafer Etching)

  • 김재환;이용일;홍상진
    • 반도체디스플레이기술학회지
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    • 제19권2호
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    • pp.77-81
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    • 2020
  • Silicon wafer etching in micro electro mechanical systems (MEMS) fabrication is challenging to form 3-D structures. Well known Si-wet etch of silicon employs potassium hydroxide (KOH), tetramethylammonium hydroxide (TMAH) and sodium hydroxide (NaOH). However, the existing silicon wet etching process has a fatal disadvantage that etching of the back side of the wafer is hard to avoid. In this study, a wet etching bath for 150 mm wafers was designed to prevent back-side etching of silicon wafer, and we demonstrated the optimized process recipe to have anisotropic wet etching of silicon wafer without any damage on the backside. We also presented the design of wet bath for 300 mm wafer processing as a promising process development.

다공성 수침-평판전극간의 수적 방출 특성 (Water Droplet Ejection Characteristics of a Wet Porous Point-Plate Airgap)

  • 정재승;이우석;문재덕
    • 전기학회논문지
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    • 제58권10호
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    • pp.2005-2010
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    • 2009
  • Water droplet ejection characteristics of a point-to-plate airgap, with a wet porous point as a corona electrode, has been investigated. And the water droplet traces, charge, mass and number were measured experimentally. More particles are observed with wet porous point than metal point because the corona-discharging wet porous point can eject a number of water droplets. The water droplets ejected from the positive-corona-discharging wet porous point showed very fine traces as compared with those from the negative-corona-discharging wet porous point. Moreover, the water droplets ejected from the AC-corona-discharging wet porous point showed granular-like larger traces. It was shown that the weak corona discharge can eject smaller water droplets with larger ratio of mass-to-charge than the intense corona discharge.

FERMENTATION QUALITY AND NUTRITIVE VALUE OF BARLEY STRAW AND WET BREWERS' GRAINS SILAGE

  • Ridla, M.;Uchida, S.
    • Asian-Australasian Journal of Animal Sciences
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    • 제7권4호
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    • pp.517-522
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    • 1994
  • Three experiments were carried out to evaluate the fermentation process and subsequent nutritional quality of silage made from dried and fresh barley straw with and without the addition of wet brewers' grains. The treatments were: 1 kg of dried straw with 600 g of water but no wet brewers' grains (I - 0) as a control, and the same straw mixed with 2 kg (I - 2), 3 kg (I - 3), 4 kg (I - 4), or 5 kg (I - 5) of wet brewers' grains as treatments in Experiment I; and 2 kg of fresh straw without wet brewers' grains (II - 0) as a control, and the same fresh straw mixed with 2 kg (II - 1), 4 kg (II - 2), 6 kg (II - 3), or 8 kg (II - 4) of wet brewers' grains as treatments in Experiment II. Each material prepared was ensiled in 5 L (vinyl) bag silos, and the silos placed in a chamber of $21^{\circ}C$ for 10 (Exp. I) or 7 (Exp. II) months. The fermentation quality and nutritive value of the barley straw silages produced were markedly improved by mixing them with wet brewers' grains. Increasing levels of wet brewers' grains caused on increase in fermentation quality. The in vitro dry matter digestibility of silages was also increased by adding wet brewers' grains. Two semi scale pilot silages, experiment III, prepared from dried and fresh barley straw mixed with wet brewers' grains were fed to wether sheep. These silages, which contained 50% barley straw and 50% wet brewers' grains by dry weight, were moderate apparent digestibility and supplied of about 50% TDN and DCP.

친수성 콘택트렌즈 측정용 Wet Cell 홀더 개발에 관한 연구 (Study on the Development of Wet Cell Holder for the Measurement of Hydrophilic Contact Lens)

  • 송경석;임현선;주석희
    • 한국안광학회지
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    • 제20권4호
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    • pp.455-462
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    • 2015
  • 목적: 친수성 콘택트렌즈 정점굴절력 측정 방식중 하나인 wet cell 측정법을 활용한 국산화 측정 홀더와 프로그램 개발에 관한 연구를 위해 현재 사용되어지고 있는 Poster wet cell 홀더와 함수율별 굴절력의 측정값을 비교 분석하였다. 방법: 안경원에서 사용 중인 기존 제품과 새롭게 개발된 국산제품에 식염수를 채워 넣고 소프트콘택트렌즈의 굴절력을 측정하였다. 실험에 사용한 친수성 콘택트렌즈는 안경원에서 많이 사용되고 있는 국내산 렌즈를 사용하였으며, 함수율별과, 구면굴절력별로 분류하여 각각 실험하였다. 결과: wet cell 방식으로 콘택트렌즈 굴절력 측정 시 새롭게 개발한 홀더의 경우 자동렌즈미터를 사용하여 굴절력을 측정한 결과 -3.00 D에서 함수율 38%는 -3.01 D, 함수율 45%는 -3.00 D, 함수율 58%는 -2.98 D로 측정되었으며, Poster wet cell 홀더를 사용하여 렌즈를 측정한 결과 -3.00 D에서 함수율 38%는 -3.60 D, 45%는 -3.06 D, 58%는 -2.46 D로 각각 측정되었다. 결론 : 고함수율에서 굴절력 측정값은 wet cell 방식의 두 홀더 모두 낮게 나타났으며, 새롭게 개발된 홀더와 프로그램을 통한 자동렌즈미터의 측정값이 기존의 Poster soft contact lens wet cell 측정방식에 비해 더 정확한 굴절력 측정 결과를 나타내었다.

Effects of Wet Feeding of Diets with or without Food Waste on Growth Performance and Carcass Characteristics in Finishing Pigs

  • Moon, J.S.;Kwon, I.K.;Chae, B.J.
    • Asian-Australasian Journal of Animal Sciences
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    • 제17권4호
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    • pp.504-510
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    • 2004
  • Two experiments were conducted. In expt. 1, a total of fifty-four pigs (L$\times$Y$\times$D, 56.14$\pm$1.7 kg) were used for a feeding trial to determine the effect of wet feeding of a commercial-type diet without food waste (FW). Treatments were dry (Control), wet (WF) and wet+dry feeding (WDF). For wet feeding, the diet was mixed with water at a ratio of 1:2.5 (feed:water). A wet feed was given during the whole experimental period for the WF group, but the dry feed was given during the finisher period for the WDF group. In expt. 2, a total of fifty-four pigs(L$\times$Y$\times$D, 55.7$\pm$1.8 kg) were used for a feeding trial to determine the effect of wet feeding of FW. Treatments were a commercial-type dry (Control), wet fermented food waste (WFFW) and WFFW+dry feeding (WFFW+DF). For wet feeding of fermented food waste, however, some ingredients (concentrate) were added to make nutrient contents comparable to the control diet. The FW collected was ground ($\leq$5 mm), heated with a steam jacket (140$\pm$3$^{\circ}C$) and fermented with probiotics for one day in a steel container at 30-40$^{\circ}C$. For the WFFW group, the wet feed was given during the whole experimental period, but a dry feed was given during finisher period for the WFFW+DF group. In expt. 1, during the grower period, pigs fed wet feed showed higher average daily gain (ADG) and feed conversion ratio (FCR) than those fed only dry feed (p<0.05). During the finisher period, pigs in the WDF group showed better ADG and FCR than the control group. During the entire experimental period, pigs in the WDF group grew faster (p<0.05) than those in the control group, and the same trend was found in FCR. Also, dressing percentage, backfat thickness, lean %, and pork color were not affected by the wet feeding of diets in this study. In expt. 2, during the grower period, pigs fed diets containing FW showed lower (p<0.05) ADG than those fed the control diet. But FCR was better (p<0.05) in pigs fed FW than in the control group. During the finisher period, pigs in the WFFW+DF group grew faster (p<0.05) than those in the control and WFFW groups. During the entire experimental period, pigs fed the control diet showed better ADG (p<0.05) than those fed FW, but feed intake and FCR were vice versa. Dressing percentage was lower (p<0.05) in the WFFW than in the control group, but backfat was thinner in the WFFW group than in the control group. In summary, it can be concluded that wet feeding of formula feed can improve daily gain, however, feeding fermented wet food waste may reduce daily gain of finishing pigs, even though it was fermented and the nutrient was fortified with concentrates. In addition, dry feeding of a formula feed during the finishing period can improve daily gain in pigs fed a wet feed with or without food waste during the grower period.

Comparison of Meat Quality Characteristics of Wet- and Dry-aging Pork Belly and Shoulder Blade

  • Hwang, Young-Hwa;Sabikun, Nahar;Ismail, Ishamri;Joo, Seon-Tea
    • 한국축산식품학회지
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    • 제38권5호
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    • pp.950-958
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    • 2018
  • The physicochemical characteristics and oxidative stability of wet-aged and dry-aged pork cuts were investigated at different aging periods (1, 7, 14 and 21 d). Samples were assigned into four groups in terms of shoulder blade-wet aging (SW), shoulder blade-dry aging (SD), belly-wet aging (BW), and belly-dry aging (BD). SD showed significantly higher pH at 21 d of aging than the other samples. Wet-aged cuts had significantly higher released water (RW) %, lightness ($L^*$) and shear force compared to the dry-aged meats. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed greater degradation of proteins for dry-aged cuts than the wet-aged cuts. At the end of aging, wet-aged cuts showed significantly lower thiobarbituric acid-reactive substances (TBARS) value than the dry-aged samples, indicating higher oxidative stability for wet-aged pork cuts. However, dry-aging led to higher degradation of proteins resulting in increased water-holding capacity (WHC) and decreased shear force value.

다단 습식 신선공정 해석 및 적용 (Analysis of Multi-Pass Wet Wire Drawing Process and Its Application)

  • 이상곤;김병민
    • 소성∙가공
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    • 제14권8호통권80호
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    • pp.689-695
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    • 2005
  • Multi-pass wet wire drawing process is used to produce fine wire in the industrial field. The production of fine wire through multi-pass wet wire drawing process with appropriate dies pass schedule would be impossible without understanding the relationship among many process parameters such as material properties, dies reduction, friction conditions, drawing speed etc However, in the industrial field, dies pass schedule of multi-pass wet wire drawing process has been executed by trial and error of experts. This study investigated the relationship among many process parameters quantitatively to obtain the important process information fur the appropriate pass schedule of multi-pass wet wire drawing process. Therefore, it is possible to predict the many important process parameters of multi-pass wet wire drawing process such as dies reduction, machine reduction, drawing force, backtension force, slip rate, slip velocity rate, power etc. The validity of the analyzed drawing force was verified by FE simulation and multi-pass wet wire drawing experiment. Also, pass redesign was performed based on the analyzed results, and the wire breakage between the original pass schedule and the redesigned pass schedule was compared through experiment.

반송제어모드를 이용한 인라인 식각/세정장치의 ITO 전극형성기술 (ITO Patterning of an In-line Wet Etch/Cleaning System by using a Reverse Moving Control System)

  • 홍성재;임승혁;한형석;권상직;조의식
    • 제어로봇시스템학회논문지
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    • 제14권4호
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    • pp.327-331
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    • 2008
  • An in-line wet etch/cleaning system was established for the research and development in wet etch process as a formation of electrode such as metal or transparent conductive oxide layer. A reverse moving system was equipped in the in-line wet etch/cleaning system for the alternating motion of glass substrate in a wet etch bath of the system. Therefore, it was possible for the glass substrate to be moved back and forth and it was possible to reduce the size of the system by using the reversing moving system. For the effect of the alternating motion of substrate on the etch rate in the in-line wet etch bath, indium tin oxide(ITO) patterns were obtained through wet etch process in the in-line system in which the substrate was moved back and forth. From the CD(critical dimension) skews resulted from the ADI CD and ACI CD of the ITO patterns, it was concluded that the alternating motion of glass substrate are possible to be applied to the mass production of wet etch process.

Traffic-induced vibrations at the wet joint during the widening of concrete bridges and non-interruption traffic control strategies

  • Junyong Zhou;Zunian Zhou;Liwen Zhang;Junping Zhang;Xuefei Shi
    • Computers and Concrete
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    • 제32권4호
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    • pp.411-423
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    • 2023
  • The rapid development of road transport has increased the number of bridges that require widening. A critical issue in the construction of bridge widening is the influence of vibrations of the old bridge on the casting of wet joint concrete between the old and new bridges owing to the running traffic. Typically, the bridge is closed to traffic during the pouring of wet joint concrete, which negatively affects the existing transportation network. In this study, a newly developed microscopic traffic load modeling approach and the vehicle-bridge interaction theory are incorporated to develop a refined numerical framework for the analysis of random traffic-bridge coupled dynamics. This framework was used to investigate traffic-induced vibrations at the wet joint of a widened bridge. Based on an experimental study on the vibration resistance of wet joint concrete, traffic control strategies were proposed to ensure the construction performance of cast-in-site wet joint concrete under random traffic without interruption. The results show that the vibration displacement and frequency of the old bridge, estimated by the proposed framework, were comparable with those obtained from field measurements. Based on the target peak particle velocity and vibration amplitude of the wet joint concrete, it was found that traffic control measures, such as limiting vehicle gross weight and limiting traffic volume by closing an additional traffic lane, could ensure the construction performance of the wet joint concrete.

한국산 희귀조류 수 종에 대한 중금속 축적 (Heavy Metal Accumulation in Some Korean Rare Bird Species)

  • 이두표
    • The Korean Journal of Ecology
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    • 제27권3호
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    • pp.141-146
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    • 2004
  • 본 연구는 여러 가지 원인으로 사망한 한국산 희귀조류 4목 16종 76개체를 이용하여 납과 카드뮴의 조직 축적레벨을 밝히고 오염수준을 비교 검토하였다. 남의 경우 전반적으로 간보다 신장과 뼈에서 높은 농도를 나타냈다. 간조직에는 평균농도는 0.47 ㎍/wet g(큰고니 Cygnus cygnus)∼3.74 ㎍/et g(쇠부엉이 Asio flammeus)의 범위를 나타냈고, 납의 독성 여부를 수준별로 보면 비오염수준인 2 ㎍/wet g 이하에 해당하는 개체가 51.3%(39개체), 오염수준이 10 ㎍/wet g 이상에 해당하는 개체가 2.6%(2개체)로 나타났다. 따라서 상당수의 한국산 희귀조류가 만성적인 납 오염에 노출되어 있는 것으로 판단된다. 카드뮴의 경우 신장조직에서 가장 높게 나타났으며 간과 뼈에서는 비슷한 경향을 보였다. 신장조직에서의 평균농도는 0.06 ㎍/wet g(수리부엉이)∼1.75 ㎍/wet g(새홀리기 Falco subbuteo)의 범위를 나타냈고 소쩍새 1개체를 제외하고 모두 비오염 수준에 해당하였다.