• 한국수소및신에너지학회논문집
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• 제32권3호
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• pp.189-195
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• 2021

A compressed hydrogen tank is to be repressurized to 40 bar by being connected to a high-pressure line containing hydrogen at 50 bar and 25℃. Hydrogen filling time and the corresponding hydrogen temperature has been estimated when the filling process stopped according to several thermodynamic models. During the process of cooling the hydrogen tank, hydrogen temperature and pressure vs. time estimation was performed using Aspen Dynamics. Filling time, hydrogen temperature after filling hydrogen gas, cooling time and the final tank pressure after tank filling process have been completed according to the thermodynamic models are almost same.

• Journal of Welding and Joining
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• 제25권3호
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• pp.45-50
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• 2007

The present study is devoted to investigate the transient flow and to estimate the filling time fur underfill process by using the numerical model established on the fluid momentum equation. For optimization of the design and selection of process parameters, this study extensively presents an estimation of the filling time in the view points of some important factors related to underfill materials and flip-chip geometry. From the results, we conclude that the filling time changes with respect to the under fill materials because of different viscosity, surface tension coefficient and contact angle. It reveals that, as the gap height increases, the filling time decreases substantially, and goes to the saturated values.

• 대한기계학회논문집B
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• 제22권1호
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• pp.104-112
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• 1998

The mold filling process has been a central issue in the development of numerical methods to solve the casting processes. A mold filling which is inherently transient free surface fluid flow, is important because the quality of casting highly depends on such phenomenon, Most of the existing numerical schemes to solve mold filling process have severe limitations in time step restrictions or Courant criteria since explicit time integration is used. Therefore, a large computation time is required to analyze casting processes. In this study, the well known SOLA-VOF method has been modified implicitly to simulate the mold filling process. Solutions to example filling problems show that the proposed method is more efficient in computation time than the original SOLA -VOF method.

• 대한기계학회논문집B
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• 제24권1호
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• pp.102-113
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• 2000

In this study, a three-dimensional gravity casting problem has been examined to investigate a coupled phenomenon of the filling and solidification process. This work simultaneously considers the two key phenomena of metal casting : the fluid flow during mold filling, and solidification process. The VOF method is used to analyze the free surface flow during filling and the equivalent specific heat method is employed to model the latent heat release during solidification. The time-implicit filling algorithm is applied to save the computational time for analyzing the mold filling process. The three-dimensional benchmark problem used in the MCWASP VII has been solved using both the implicit and explicit algorithm, and the present results are compared with the benchmark experimental results and the other numerical results.

• Animal Bioscience
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• 제34권11호
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• pp.1776-1783
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• 2021

Objective: This project aimed to evaluate the effects of both different additives and filling methods on nutritive quality, fermentation profile, and in situ digestibility of whole plant corn silage. Methods: Whole plant corn forage harvested at 26.72% dry matter (DM) was chopped and treated with two filling methods, i) fill silos at one time (F1), ii) fill silos at three times (F3), packing samples into one/three silo capacity at the first day, another one/three capacity at the second day, then one/three at the third day, three replicates. For each replicate, samples were treated with three additives, i) control (CTRL, no additive), ii) Sila-Max (MAX, Ralco Nutrition Inc., Marshall, MN, USA), and iii) Sila-Mix (MIX, Ralco Nutrition Inc., USA). With three replicates of each secondary treatment, there were nine silos, 54 silos in total. Each silo had a packing density of 137.61 kg of DM/m3. All silos were weighed and stored in lab at ambient temperature. Results: After 60 d of ensiling, all items showed good silage fermentation under MAX filled one time or three times (p<0.01). Higher silage quality for all additives was obtained at filling one time than that filled three times (p<0.01). The highest DM and lowest DM loss rate (DMLR) occurred to MAX treatment at two filling methods (p<0.01); Digestibility of acid detergent fiber, neutral detergent fiber (NDF), and curde protein had the same results as silage quality (p<0.01). Yield of digestible DM and digestible NDF also showed higher value under MAX especially for filling one time (p<0.05). Conclusion: All corn silages showed good fermentation attributes (pH<4.0). The forage filled one time had higher silage quality than that filled three times (p<0.01). MAX with homofermentative lactic acid bacteria enhanced the lactic acid fermentation, silage quality and nutrient digestibility, and so improved the digestible nutrient yield.

• 한국지반신소재학회논문집
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• 제17권1호
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• pp.119-126
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• 2018

도심지에서 발생하고 있는 지반공동은 점차 증가하고 있는 추세이다. 그러나 지하에는 지하철 및 상하수도 관거, 통신시설 등 많은 구조물과 지하매설물이 복잡하게 상존하기 때문에 지반함몰이 발생할 경우 그 피해규모가 크고, 복구를 하는데 있어 시간적 경제적으로 큰 어려움이 따른다. 이에 지반공동을 보다 신속하게 복구하기 위한 새로운 방법으로 수용성 폴리머 기반의 무기질계 혼화재를 개발한 바 있고, 개발 보강재를 효율적으로 공동 내부에 주입할 수 있도록 하는 주입시스템 구축이 필요하다. 구축하고자 하는 주입시스템은 비개착식이고 별도의 플랜트 설치를 필요로 하지 않아 시간적 경제적으로 유리하며 공압을 이용하여 보강재를 공동내부에 빠르게 충전시킬 수 있어 지반함몰 발생 시 긴급복구를 가능하게 해주는 기술이라고 할 수 있다. 주입시스템 구축을 위해 충전속도 및 충전율 등을 실험을 통해 평가하였고 개별요소해석 프로그램(EDEM)을 이용한 시뮬레이션을 통해 지반 및 주변의 다양한 조건에서도 가능한 충전양상을 확인할 수 있었다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.644-647
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• 2009

In this paper, the study is researched for related safety standards having experiments concerning temperature changes in type IV cylinder of the Hydrogen fuel cell vehicle. Experiments were performed to acquire temperature data of type IV cylinder according to filling time. The experimental results are shown that internal temperatures of type Ⅳ vessel are over $85^{\circ}C$ at all measured points after 5 minutes at filling 35 MPa and the highest temperature is getting lower when the residual gases are more remained. Consequently, the safety standards need properly limited value through further study for filling flow rate and filling time.

• Advanced Composite Materials
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• 제16권3호
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• pp.207-221
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• 2007

The filling process of resin injection/compression molding (I/CM) can be divided into injection and compression phases. During the resin injection the mold is kept only partially closed and thus a gap is present between the reinforcements and the upper mold. The gap results in preferential flow path. After the gap is filled with the resin, the compression action initiates and forces the resin to penetrate into the fiber preform. In the present study, the resin flow in the gap is simplified by using the Stokes approximation, while Darcy's law is used to calculate the flow field in the fiber mats. Results show that most of the injected resins enter into the gap during the injection phase. The resin injection time is extremely short so the duration of the filling process is determined by the final closing action of the mold cavity. Compared with resin transfer molding (RTM), I/CM process can reduce the mold filling time or injection pressure significantly.

• Restorative Dentistry and Endodontics
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• 제12권2호
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• pp.17-23
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• 1987

The purpose of this study was to evaluate the sealing properties of endodontic cavity filling materials according to the time intervals after filling. Access cavities were prepared in extracted human premolar or molar teeth and filled with caviton, zinc oxide eugenol cement, zinc oxide eugenol cement with a base of gutta percha stopping and gutta percha stopping. After filling at the intervals of immediate, 2 days and 2 weeks the teeth were immersed for 2 weeks in 1% methylene blue solutions. Longitudinal sections were obtained from approximately center of teeth and the depth of dye penetration into the access cavities were observed by 10${\times}$macrolens. The following results were obtained. I. All the materials experimented showed varying depth of dye penetration. 2. Of the material tested, caviton showed the best marginal sealing qualities regardless of the time intervals after filling and the sealing properties of the gutta percha stopping was the worst. 3. Both in zinc oxide eugenol cement and zinc oxide eugenol cement with a base of gutta percha stopping, the fillings allowed to mature for 2 days in normal saline solution showed the best sealing properties and those with no maturing time revealed the worst sealing qualities. 4. The sealing qualities of zinc oxide eugenol cement with a base of gutta percha stopping revealed slightly lower depth of dye penetration than that of zinc oxide eugenol cements.

• Journal of Welding and Joining
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• 제32권3호
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• pp.19-26
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• 2014

Through Silicon Via (TSV) technology is the shortest interconnection technology which is compared with conventional wire bonding interconnection technology. Recently, this technology has been also noticed for the miniaturization of electronic devices, multi-functional and high performance. The short interconnection length of TSV achieve can implement a high density and power efficiency. Among the TSV technology, TSV filling process is important technology because the cost of TSV technology is depended on the filling process time and reliability. Various filling methods have been developed like as Cu electroplating method, molten solder insert method and Ti/W deposition method. In this paper, various TSV filling methods were introduced and each filling materials were discussed.