• International Journal of Ocean System Engineering
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• 제2권4호
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• pp.239-243
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• 2012

The cylinder liner of a low speed engine is one of the most important parts of the marine diesel engines used in merchant ships. However, a sufficient degree of precision in the manufacturing method for these cylinder liners has never existed. Conventional honing stones have always been used for machining large marine cylinder liners. Therefore, it is necessary to develop a honing process that optimizes the honing characteristics. In this study, a CBN honing stone was manufactured to improve the honing performance for a cylinder liner and shorten the processing time, and machining experiments on a practical cylinder liner were carried out. Then, a comparison was made between the CBN honing and honing with a conventional GC stone using parameters such as the honing time, machining quantity, and honing cost. As a result, for a #60 CBN stone, the machining amount was significantly improved compared to the conventional one by about $1.1{\mu}m$/min, and in respect to the machining cost, a reduction of about 57% was achieved. However, an improvement in the process with a #800 CBN stone could not be expected because it did not show a significant difference compared to the case of the existing stone. From the above results, if the liner were honed using a CBN honing stone, the rough machining and intermediate processing during an early stage of the honing process were excellent compared to the conventional one. However, we could not find a significant difference in the case of finish honing.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2004년도 제22회 춘계학술대회논문집
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• pp.453-459
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• 2004

An axially staged combustor equipped with an LPP combustion system and CMC liner walls has been investigated for stable combustion and low NOx emissions for the ESPR project. Several fuel injectors were designed and manufactured for the LPP burner, and single sector combustor tests were conducted to evaluate fundamental combustion characteristics such as emissions, instabilities, auto-ignition, and flash back at typical operating conditions from idle to Mn 2.2 cruise. The latest test results showed that the LPP burner had a good potential for the low NOx target. It was also found that the NOx emission level was greatly affected by a distortion in the air flow velocity field upstream of the LPP burner due to the diffuser and fuel feed arm. The CMC material was investigated to apply for the high temperature and low NOx combustor. Annular combustor liner walls were manufactured with the CMC material, and they have been tested at low pressure conditions to evaluate the soundness of the material and the mounting and seal system. This paper reports the latest research activities on the LPP combustion system and CMC liner walls for the ESPR project.

• Nuclear Engineering and Technology
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• 제54권4호
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• pp.1221-1229
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• 2022

In this work, the guided wave de-bonding area-detecting technique was studied for application to containment liner plates in nuclear power plant areas. To apply this technique, an appropriate Lamb wave mode, symmetric and longitudinal dominance, was verified by the frequency shifting technique. The S0 2.7 MHz mm Lamb wave mode was chosen to realize quantitative experimental results and their visualization. Results of the bulk wave, longitudinal wave mode, and comparison experiments indicate that the wave mode was able to distinguish between the de-bonded and bonded areas. Similar to the bulk wave cases, the bonded region could be distinguished from the de-bonded region using the Lamb wave approach. The Lamb wave technique results showed significant correlation to the de-bonding area. As the de-bonding area increased, the Lamb wave energy attenuation effect decreased, which was a prominent factor in the realization of quantitative tomographic visualization. The feasibility of tomographic visualization was studied via the application of Lamb waves. The reconstruction algorithm for the probabilistic inspection of damage (RAPID) technique was applied to the containment liner plate to verify and visualize the de-bonding condition. The results obtained using the tomography image indicated that the Lamb wave-based RAPID algorithm was capable of delineating debonding areas.

• Journal of Advanced Marine Engineering and Technology
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• 제16권4호
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• pp.78-87
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• 1992

The experimental study and theoretical analysis are made in order to investigate a new refrigeration system, R-22 and R-502 or R-13 cascade compressor with panel type cooler, for tuna long liner. The experimental apparatus consists with the cascade unit, 1.5 HP R-502 compressor in the first stage and 1 HP R-22 compressor in the second stage, and 3 $m^2$ cold storage room with a direct expansion panel type cooler. The main result are as follows: 1. The energy saving and C.O.P. of the R-22 and R-502 or R-22 and R-13 cascade are improved much higher than two stage compressor. 2. For the point of simplicity of design, installation, and running cost, the panel type cooler is much better than traditional hair pin coil type cooler. 3. From the experimental data and analysis, the R-22 and R-502, or R-22 and R-13 cascade compressor with panel type cooler is recommended for a new refrigeration equipment of the tuna long liner.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.1095-1096
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• 2011

• 한국항해항만학회지
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• 제27권3호
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• pp.297-306
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• 2003

As the competition in the liner shipping industry is becoming fiercer, the shipping company is trying to find the way to keep the best competitive position by reducing the cost level as low as possible and offering the best quality of service to their customer. In order to achieve this goal, the selection of port and terminal that have the best quality of service and cost effective structure is essential for the shipping line, where they can only have a chance to save the money. In this context, the paper compares three European container terminals in order to understand the factors that have to be considered in the decision making process for the selection of terminal. And its advantages and disadvantages of each type of container terminal operation system were analyzed from the liner shipping company's point of view in terms of cost, time, flexibility, stability, hinterland connection, geographical position and terminal productivity. It is obvious that the cost factors are very important for liner shipping company to select their terminal. However, there might be even more important factors than the cost factors, such as quality of port and terminal service, mutual trust, and possibility of future development.

• 한국지반공학회논문집
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• 제19권5호
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• pp.263-272
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• 2003

여러 가지 형식의 지오신세틱스가 개발되고 있는데, 설계 수명에 대한 신뢰성, 화학적 생물학적 내구성, 그리고 천공(꿰뚫림)에 대한 저항성 등에 대한 문제가 있는데도 불구하고 이들의 적용 분야는 증가 추세에 있다. 토공구조물이나 차수구조물에서 천공(꿰뚫림) 저항에 대한 문제는 해결되어야 할 중요한 문제로 드러나고 있다. 본 연구에서는 차수구조에 사용되는 여러 가지의 지오신세틱스의 천공(꿰뚫림) 저항성에 대하여 모형실험을 통하여 비교 분석하였다. 지오신세틱스에 천공(꿰뚫림)을 발생시키는 기구로서 두 가지 형식의 기구와 강자갈 그리고 쇄석을 사용하였다. 연구결과에 따르면, 천공기구의 형태는 재료의 천공(꿰뚫림)저항성에 큰 영향을 끼치고, 천공(꿰뚫림)강도의 크기는 천공(필뚫림) 발생기구의 형태와 재료에 따라 불규칙적인 것으로 나타났다.

• International Journal of Internet, Broadcasting and Communication
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• 제12권3호
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• pp.74-86
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• 2020

This study discussesresearch and development of large-sized 3D printers that can be applied to construction and civil engineering for various designs of protective casing on foam liner for concrete exteriors. The consistent use of concrete represents the current surroundings. However, concrete exteriors in Korea have not considered the regional characteristics, but the concrete has been poured solely for economical aspects for the last decade or two. There are many cases of poor installation and not enough design development projects to correct it. This study was conducted to apply various patterns, regional characteristics, and 3D printing for protective casing design for foam liner to create various designs for the concrete walls. Therefore, we started researching on a large 3D printer, and designed and developed this system. Considering the chronological process, the properties of concrete structures were identified, the application of designs for concrete in Korea and abroad and the 3D printing materials for the protective casing were surveyed and analyzed, and a stereotype was produced in the first year to study designs for the beauty of concrete surfaces. In the second year, images of regional characteristics were gathered, design ideas for regional promotion were derived, virtual images were produced along with design modeling to simulate the appearances, and verify the effect of application and promotion. Finally, in the third year, the 3D printer for concrete foam liner was constantly improved to analyze the 3D printing program and the various library elements to complete an actual large-sized 3D printer.

• The Journal of Advanced Prosthodontics
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• 제8권6호
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• pp.479-488
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• 2016

PURPOSE. The aim of this study was to test the modulus of elasticity (E) across the interfaces of yttria stabilized zirconia (YTZP) / veneer multilayers using nanoindentation. MATERIALS AND METHODS. YTZP core material (KaVo-Everest, Germany) specimens were either coated with a liner (IPS e.max ZirLiner, Ivoclar-Vivadent) (Type-1) or left as-sintered (Type-2) and subsequently veneered with a pressable glass-ceramic (IPS e.max ZirPress, Ivoclar-Vivadent). A $5{\mu}m$ (nominal tip diameter) spherical indenter was used with a UMIS CSIRO 2000 (ASI, Canberra, Australia) nanoindenter system to test E across the exposed and polished interfaces of both specimen types. The multiple point load - partial unload method was used for E determination. All materials used were characterized using Scanning Electron Microscopy (SEM) and X - ray powder diffraction (XRD). E mappings of the areas tested were produced from the nanoindentation data. RESULTS. A significantly (P<.05) lower E value between Type-1 and Type-2 specimens at a distance of $40{\mu}m$ in the veneer material was associated with the liner. XRD and SEM characterization of the zirconia sample showed a fine grained bulk tetragonal phase. IPS e-max ZirPress and IPS e-max ZirLiner materials were characterized as amorphous. CONCLUSION. The liner between the YTZP core and the heat pressed veneer may act as a weak link in this dental multilayer due to its significantly (P<.05) lower E. The present study has shown nanoindentation using spherical indentation and the multiple point load - partial unload method to be reliable predictors of E and useful evaluation tools for layered dental ceramic interfaces.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.453-460
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• 2004

To prevent penetration of rainwater into the landfill site is the main purpose of the final cover in landfill sites. Conventional designs of landfill covers uses geotextiles such as geomembrane and GCL, and clay liners to lower the permeability of final covers of landfill sites. However, differential settlement and the variation of temperature in landfill sites cause the development of cracks or structural damage inside the final cover and it is also difficult to obtain clay - the main material of the compacted clay liner in Korea. Thus the former final cover system that suggests geomembrane and GCL or compacted clay liner has several limitations. Therefore, an alternative method is necessary and one of them is the application of SRSL(self-Recovering Sustainable Liner) material. SRSL is two different layers consist of individual materials that react with each other and form precipitates, and with this process lowers the permeability of the landfill final cover. SRSL generally is made up of two layers, so that when a internal crack occurs the reactants of the two layers migrate towards the crack and heal it by forming another liner. In this study the applicability of SRSL material for landfill final cover was examined by performing; (1) jar test to verify the formation of precipitate in the mixture of each reactants, (2) falling head test considering the field stress in order to confirm the decrease of permeability or prove that the hydraulic condctivity is lower than the regulations, (3) compression tests to judge weather if the strength satisfies the restricts for landfills, (4) freeze/thaw test to check the applicability of SRSL for domestic climate. In addition, the application of waste materials in the environmental and economical aspect was inspected, and finally the possibility of secondary contamination due to the waste materials was examined by performing elution tests.