• Title/Summary/Keyword: Filling ability

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A study on Resin Filling Analysis and Experiment by VAP and VaRTM Processes (VaRTM과 VAP 공정의 수지 충진실험 및 해석에 관한 연구)

  • Dong-Hwan Yoon;Kyeong-Ho Seo;Yu-Jung Kwon;Jin-Ho Choi
    • Composites Research
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    • v.36 no.5
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    • pp.310-314
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    • 2023
  • VaRTM(Vacuum assisted resin transfer molding) and VAP(Vacuum assisted process) processes are a type of RTM(Resin transfer molding) process, and are typical out-of-autoclave (OOA) processes that can manufacture large structures at low cost. In this paper, a resin filling test was conducted to compare the VaRTM and VAP processes, and the filling process and dimensional stability were compared. In addition, an analysis method to simulate the filling process was developed, and a dielectric sensor was used to detect the flow front of the resin, which was compared with the analysis results. From the resin filling test, the total filling time of the composite plate was measured to be 48 minutes for the VAP process and 145 minutes for the VaRTM process, and the filling time by the VAP process was reduced by about 67%. In addition, it was confirmed that the VAP process was superior to the VaRTM process in the thickness control ability and uniformity of the composite plate.

An Experimental Comparison of the Fluidity of G-class cement with Portland cement (지열발전을 위한 지열정 시멘트용 G-class시멘트와 일반 포틀랜드시멘트와의 유동성 비교실험)

  • Jeon, Jong-Ug;Won, Jong-Muk;Choi, Hang-Seok
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.8 no.2
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    • pp.1-8
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    • 2012
  • The G-class cement is usually used for geothermal well grouting to protect a steel casing which is equipped in a geothermal well to transfer geothermal water from deep subsurface to ground surface. In geothermal grouting process, obtaining appropriate fluidity is extremely important in order to fill cement grout flawlessly. In this paper, a series of the V-funnel and Slump Flow test was performed on both of the Portland cement and the G-class cement in order to compare fluidity and filling ability of those kind of cements. In the result of V-funnel test, the fluidity of G-class cement was evaluated much better than the Portland cement at the water/cement ratio of 0.8. In the case of Slump Flow test, the fluidity of G- class cement was estimated slightly better than the Portland cement at both the water/cement ratio of 0.55 and 0.8. Even though the initial fluidity and filling ability of G-class cement were relatively higher than the Portland cement, the results could be considerably changed with time. The results show that the fluidity and filling ability for geothermal well cementation can be properly controlled with water content and additives for adverse geothermal well environment.

Determination of Initial Billet using The Artificial Neural Networks and The Finite Element Method for The Forged Products (신경망과 유한요소법을 이용한 단조품의 초기 소재 결정)

  • 김동진;고대철;김병민;강범수;최재찬
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1994.10a
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    • pp.133-140
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    • 1994
  • In this paper, we have proposed a new method to determine the initial billet for the forged products using a function approximation in neural networks. the architecture of neural network is a three-layer neural network and the back propagation algorithm is employed to train the network. By utilizing the ability of function approximation of neural network, an optimal billet is determined by applying nonlinear mathematical relationship between shape ratio in the initial billet and the final products. A volume of incomplete filling in the die is measured by the rigid-plastic finite element method. The neural network is trained with the initial billet shape ratio and that of the un-filled volume. After learning, the system is able to predict the filling region which are exactly the same or slightly different to results of finite element method. It is found that the prediction of the filling shape ratio region can be made successfully and the finite element method results are represented better by the neural network.

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Guideline for Filling Performance of Concrete for Modular LNG Storage Tanks (모듈형 LNG 저장탱크용 콘크리트 충전성능 가이드라인 제시)

  • Lee, Dong Kyu;Lee, Keon Woo;Park, Gi Joon;Kim, Sung Wook;Park, Jung Jun;Kim, Young Jin;Choi, Myoung Sung
    • Journal of the Korean Society of Safety
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    • v.33 no.2
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    • pp.86-93
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    • 2018
  • Recently, the use of composite steel plate concrete structural modules filled with concrete between steel plates of complex internal structure, in which a large amount of studs are installed, is increasing in order to reduce the weight and to increase workability of structures such as LNG storage tanks. However, in Korea, there is no systematic criterion for evaluating the construction performance of composite steel plate concrete structural modules. Therefore, in this study, we propose a filling guideline of concrete for composite steel plate structural module. For this purpose, high filling performance concrete with general strength range was formulated and tested for filling ability and permeability for each formulation. Rheology analysis was performed to quantitatively evaluate the flow characteristics of concrete. The reliability of $T_{500}$ and plastic viscosity was evaluated to reflect the results of each test, and a guideline for high filling concrete satisfying the reliability of 0.9 or more was derived by reflecting the results of the study on the relationship between the $T_{500}$ and plastic viscosity. Through final fill-box test, filling performance was verified and guidelines were suggested.

A SCANNING ELECTRON MICROSCOPIC EVALUATION OF THE ROOT CANAL FILLING WITH ULTRASONIC ENDODONTIC INSTRUMENT (초음파 근관기구를 이용한 근관충전법의 근관폐쇄능에 관한 주사 전자현미경적 연구)

  • Choi, La-Young;Lee, In-Sook
    • Restorative Dentistry and Endodontics
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    • v.15 no.2
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    • pp.104-114
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    • 1990
  • The purpose of this study was to evaluate the adaptation of root canal filling material to the dentinal wall of root canal and to compare the sealing ability of the root canal filling materials using ultrasonic endodontic instrument with injection-molded thermoplasticized gutta-percha filling method and lateral condensation method. Fifty fresh human single root exlracted for orthodontic treatment, were randomly selected, and instrumented by step-back technique. And then, the teeth were divided into 5 groups according to each root canal filling methods. In the experimental group 1 and group 2, the root canals were filled with gutta perdia cases using ultrasonic instrument with and without sealer. In the experimental group 3 and 4, using jection-moldeed thermoplasticized gutta-percha method by obtul$^{(R)}$ canals were filled with and without sealer. In the control group, the canals were filled with sealer by lateral candensation. And then, 5 teeth of each group were immersed in black Indian ink, decalcified and cleared. The depth of dye penetration into the root canal were evaluated with stereoscope (Reichert Ltd., USA). Among the 5 teeth remaining in each group, the single longituding grooves were made on the labial and lingual root surfaces and then immersed in the liquid nitrogen to fracture the teeth spontaneously without any distortions of gutta-percha. Each specimens were examined with X-650 Scanning Electron Microscope(Hitachi ltd, Japan) to show the adaptation to the canal wall, void, homogenicity of filling material and location of gutta-percha or sealer in the dentinal tubules of the root canal. The observations were as follows : 1. The experimental group 1 showed smaller mean dye penetration than control group, and showed the penetraton of sealer in the dentinal tubules of apical third of the root canal. 2. The experimental group 2 and group 4 showed the penetration of gutta-percha in the dentinal tubules of root canals. 3. The experimental group 1 and group 3 showed less mean dye penetration than the experimental group 2 and group 4. 4. The experimental group 1 and group 2 showed better adaptation of filling materials than control group.

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A COMPARISON OF THE APICAL SEAL PRODUCED BY EASY FILLING SYSTEM AND QUICK OBTURATION SYSTEM (Easy Filling 및 Quick Obturation System을 이용한 열연화 충전법의 치근단 밀폐도 평가)

  • Shin, Jung-In;Kum, Kee-Yeon;Lee, Sung-Jong
    • Restorative Dentistry and Endodontics
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    • v.25 no.2
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    • pp.202-211
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    • 2000
  • The aim of this study was to compare the apical sealing ability of a new thermoplasticized gutta-percha filling technique, the Easy Filling and the Quick Obturation system with lateral condensation technique and Thermafil system to evaluate their clinical acceptabilities. Fifty-two extracted single-rooted teeth were instrumented to #35 using the .04 taper ProFile system. Four groups of 12 teeth were obturated by lateral condensation technique. Thermafil system and two new thermoplasticized gutta-percha techniques, the Easy Filling system and Quick Obturation system (Meta Dental co. Ltd. Korea), respectively. Four teeth served as controls. After the teeth were immersed in 2% methylene blue dye for 48 hours, they were resected horizontally at 1mm to 5mm level from the anatomical apex using a low-speed microtome. Each section was examined under a stereomicroscope at ${\times40}$ magnification and photographed. After each image was scanned, the leakage area was measured at each level using Brain 3 (Nosdia Tech., Korea) software. Leakage ratio was calculated for each group and was analyzed statistically to come up with the following results: 1. At 1mm level, the Quick Obturation system had the largest amount of apical leakage and it was statistically significant when compared with the lateral condensation group and the Thermafil group (p<0.05). 2. At 2mm and 3mm level, there were no significant difference of apical leakage among all four groups (p>0.05), and from 4mm level, no apical dye penetration was observed in all the groups. In conclusion, the apical seal produced by Easy Filling system and the Quick Obturation system was comparable to lateral condensation technique and Thermafil system except for the 1mm level. More improvement of the apical seal can be expected as the operator becomes skillful with the new techniques.

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Evaluation on the buffer temperature by thermal conductivity of gap-filling material in a high-level radioactive waste repository

  • Seok Yoon;Min-Jun Kim ;Seeun Chang ;Gi-Jun Lee
    • Nuclear Engineering and Technology
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    • v.54 no.11
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    • pp.4005-4012
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    • 2022
  • As high-level radioactive waste (HLW) generated from nuclear power plants is harmful to the human body, it must be safely disposed of by an engineered barrier system consisting of disposal canisters and buffer and backfill materials. A gap exists between the canister and buffer material in a HLW repository and between the buffer material and natural rock-this gap may reduce the water-blocking ability and heat transfer efficiency of the engineered barrier materials. Herein, the basic characteristics and thermal properties of granular bentonite, a candidate gap-filling material, were investigated, and their effects on the temperature change of the buffer material were analyzed numerically. Heat transfer by air conduction and convection in the gap were considered simultaneously. Moreover, by applying the Korean reference disposal system, changes in the properties of the buffer material were derived, and the basic design of the engineered barrier system was presented according to the gap filling material (GFM). The findings showed that a GFM with high initial thermal conductivity must be filled in the space between the buffer material and rock. Moreover, the target dry density of the buffer material varied according to the initial wet density, specific gravity, and water content values of the GFM.

Relationship between the Photosynthetic Ability and Grain Filling of Japonica and Indica ${\times}$ Japonica Rice Varieties under Different Ripening Climates. Experiment I. Changes in Photosynthetic Ability of Leaf blade and Yield Components (등숙시기를 달리한 경우 Japonica 품종과 Indica ${\times}$ Japonica 품종의 광합성능력과 등숙과의 관계 - 실험 I. 수량구성요소와 엽신의 광합성능력 변화 -)

  • Lee Sok Young;Kwon Yong Woong
    • Proceedings of the Korean Society of Crop Science Conference
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    • 1986.06a
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    • pp.22-23
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    • 1986
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Study on the Relationship between Concentration of JGB and Current Density in TSV Copper filling (TSV 구리 필링 공정에서 JGB의 농도와 전류밀도의 상관 관계에 관한 연구)

  • Jang, Se-Hyun;Choi, Kwang-Seong;Lee, Jae-Ho
    • Journal of the Microelectronics and Packaging Society
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    • v.22 no.4
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    • pp.99-104
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    • 2015
  • The requirement for success of via filling is its ability to fill via holes completely without producing voids or seams. Defect free via filling was obtained by optimizing plating conditions such as current mode, current density and additives. However, byproducts stemming from the breakdown of these organic additives reduce the lifetime of the devices and plating solutions. In this study, the relationship between JGB and current density on the copper via filling was investigated without the addition of other additives to minimize the contamination of copper via. AR 4 with $15{\mu}m$ diameter via were used for this study. The pulse current was used for the electroplating of copper and the current densities were varied from 10 to $20mA/cm^2$ and the concentrations of JGB were varied from 0 to 25 ppm. The map for the JGB concentration and current density was developed. And the optimum conditions for the AR 4 via filling with $15{\mu}m$ diameter were obtained.

EVALUATION OF APICAL SEAL ACCORDING TO TYPES OF SPREADER AND COMPATIBILITY OF ACCESSORY CONE USED IN LATERAL CONDENSATION METHOD WITHOUT SEALER (Spreader의 종류와 Accessory cone의 접합성에 따른 근단폐쇄성에 관한 실험적 연구)

  • Ahn, Young-Mi;Choi, Gi-Woon
    • Restorative Dentistry and Endodontics
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    • v.19 no.2
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    • pp.461-472
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    • 1994
  • The purpose of this study was to evaluate the sealing ability according to types of spreader and compatibility of accessory cone used in lateral condensation method. 120 plastic blocks with canal preformed were instrumented with K-,H-files and Gates-Gllidden bur. Shaped plastic blocks were divided into six experimental groups according to spreader and accessory cone used in lateral condensation. Then they were obturated by lateral condensation method without -sealer. Six experimental groups were as follows: Group 1 : Filling with #30 spreader & #25 gutta-percha cone Group 2 : Filling with #30 spreader & Fine accessory cone Group 3 : Filling with #3 spreader & #25 gutta-percha cone Group 4 : Filling with #3 spreader & Fine accessory cone Group 5 : Filling with #20,#30 spreader & #25 gutta-percha cone Group 6 : Filling with #2, #3 spreader & Fine accessory cone All the blocks were stored in 100% humidor at room temperature for 2 days. Each block was placed in centrifuged for 20 minutes at 3,000 rpm. Apical leakage was mesured from the apical foramen to the most coronal level of- dye leakage in millimeter under a stereoscope. The data were analysed by ANOVA. The obtained results were as follows; 1. In groups using two spreaders(Group 5,6), the linear leakage was less than one spreader using groups(Group 1-4). 2. Tn groups using two spreaders(Group 5,6), there was no significant difference in linear leakage between standardized -spreader group and non standardized group (p>0.01). 3. When one spreader was used(Group 1-4), standardized-spreader groups showed less linear leakage than nonstandardized spreader groups(P<0.01). 4. In case of using same spreader(Groupl,2 & Group 3,4), there was no significant difference in linear leakage according to accessory cone type. 5. It needs to use one more spreaders to increase apical sealability.

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