• Geotechnical Engineering
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• v.10 no.2
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• pp.69-84
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• 1994

In the present study, the application of a method of anchored or waste tyre wall in reinforcing the unstable slope is investigated. For design purposes a method of external stability analysis of the reinforced slope, together with a method of internal stability analysis of a wall itself, is presented. In order to predict the passive resistance expected in the anchor or waste tyre Meyerhof's bearing capacity theory is moapaed and experimental results of stress distribution of a pile section under lateral loading is used. Hurray's pull-out teat results are compared with the passive resistances of anchors predicted by the proposed method, and alto the advantages in design are compared with a method of reinforced earth wall with steel strips. Finally a design example of reinforced slope using anchored or caste tyre wall is presented and the overall stability is analyzed in detail by the proposed method of analysis. The efficiency of a method of anchored or waste tyre wall is further analyzed, comparing with a method of changing geometry of the origin리 unstable slope.

• Journal of the Korean Geotechnical Society
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• v.29 no.9
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• pp.31-41
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• 2013

The use of energy pile foundation has increased for economic utilization of geothermal energy. In particular, coil-shaped ground heat exchanger (GHE) is preferred to the conventional U-shaped exchanger to ensure better efficiency of heat exchange rate. This paper presents a numerical and experimental study on the heat transfer behavior of PHC energy piles. Field thermal performance tests (TPTs) were conducted for the PHC energy piles installed in a partially saturated weathered granite soil deposit, in which two types of GHEs were considered: W and coil shaped GHEs. Besides, three-dimensional finite element analyses were also conducted, and the results were compared with the experimental results. According to the results of TPT and numerical analyses, the coil shaped GHE showed 10~15% higher heat exchange rate than the W type GHE in the PHC energy piles.

• Journal of the Korean Geotechnical Society
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• v.22 no.5
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• pp.69-81
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• 2006

The micropile, which is a kind of the in-situ manufactured pile with small diameter of $150\sim300mm$, is constructed by installing a steel bar or pipe and injecting grout into a borehole. The application fields of micropile are being gradually expanded in a limited space of down-town area, because the micropile has various advantages with low vibration and noise in method and compact size in machine, etc. Mostly, the micropile has been applied to secure the safety of structures, depending on the increment of bearing capacity and the restraint of displacement. The micropile is expected to be used in various fields due to its effectiveness and potentiality in the future. The model test, focused on the interaction between micropile and soil in this study, was carried out. The micropile is installed in a soil adjacent to footing (concept of 'soil reinforcement'). With the test results and soil deformation analysis, the reinforcement effect (relating to bearing capacity and settlement) was analysed in a qualitative and quantitative manner, respectively. Consequently, it is expected that we nay demonstrate the improvement of an efficiency and application in the design and construction of micropile.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.3C
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• pp.191-200
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• 2006

The micropile, which is a kind of the in-situ manufactured pile with small diameter of 100~300mm, is constructed by installing a steel bar or pipe and injecting grout into a borehole. The application fields of micropile are being gradually expanded in a limited space of down-town area, because the micropile has various advantages with low vibration and noise in method and compact size in machine, etc. Mostly, the micropile has been applied to secure the safety of structures, depending on the increment of bearing capacity and the restraint of displacement. The micropile is expected to be used in various fields due to its effectiveness and potentiality in the future. The model test, focused on the interaction between micropile and soil in this study, was carried out. The micropile is installed under footing(concept of "structure supporting"). With the test results and soil deformation analysis, the reinforcement effect(relating to bearing capacity and settlement) was analysed in a qualitative and quantitative manner, respectively. Consequently, it is hoped to demonstrate the improvement of an efficiency and application in the design and construction of micropile.

• Journal of the Korea Organic Resources Recycling Association
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• v.2 no.2
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• pp.19-29
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• 1994

A large volume of paper mill sludge(PMS) is produced every day from paper industries after treatments of waste water and it costs too much to dispose of the sludge. Since PMS consists mostly of biodegradable organic matter, cellulose, it is desirable to recycle it by proper treatments such as composting. In this study, experiments were conducted using a small scale reactor(12l) to establish optimum conditions for efficient composting of PMS of which initial pH, C/N ratio, and moisture content were 7.1, 28~30, and 60~65%, respectively. No heavy metals such as mercury, cadmimum, and lead were not detected in the PMS. Various levels of forced aeration, 1 minute aeration per every 30, 60, 120, 240, and 480 minutes were applied and 1 minute aeration per 60 and 120 minutes found to be proper for composting of 8l PMS in this system. Relationship between $CO_2$ production and temperatures was positively correlated with r> 0.82 suggesting that the normal decomposition of PMS by microorganisms occurred. However, under the condition of aeration interval over than 240 minutes, a negative relationship between two parameters was found indicating the occurrence of abnormal(maybe anaerobic) degradation. The amount of added nitrogen also affected composting of PMS resulting in the increase of $CO_2$ production and temperature. Semi-field tests using 100kg PMS in a static pile sysem showed that PMS could be composted efficiently under optimal environmental conditions. The parameters determining efficiency of composting such as C/N ratio, aeration, moisture content, and pH need to be monitored.

• Journal of Digital Convergence
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• v.13 no.8
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• pp.281-288
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• 2015

The container terminals use convergence technology that exchange information for cargo work, using wireless communication between the TOS(Terminal Operations System) and the handling equipments(CC, TC, YT). But if the container cargoes pile up high in the container yard, delayed cargo work and cargo working list information error happen because of communication dead spots(the worker can not receive the information) which wireless communication is disconnected. At this time the driver of the yard tractor(YT) must be able to recognize the communication state. If then, delayed cargo work and cargo working list information errors that occur in the shaded communication area can be avoided, and can process the delayed work due to wireless communication break. In this project, we have built wireless communication environment to increase the efficiency of the loading and unloading operations which the operator can respond actively, when the work is delayed and work orders result in errors. That is, the flow of the wireless communication module has been changed.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.4
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• pp.112-117
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• 2002

This study was conducted to induce the optimal composting conditions of pig manure mixed with sawdust and dried paper-mill sludge in the composting for production of high quality compost. Pig manure contains high water content and How C/N ratio because of comparatively high nitrogen content than sawdust and dried paper-mill sludge. Therefore the addition of dried paper-mill sludge and sawdust to the raw materials helps controlling the C/N and the water content of compost pile. The composting system used in the experiment was agitated static bed system. The physical properties of the mixed raw materials was not good at the working conditions in the early stage of composting. The temperature of compost heap reaches at $60^{\circ}C$within 5 day after starting composting in P-2 treatment mixed with pig manure and sawdust(56.6 : 43.4). Then the water content of P-2 was 58%. The pH in all treatments were slowly decreased as the composting was proceeded. Although the changes of T-C and T-N were not extended because of the short composting experiment period. Reduction rates of T-C in treatments were 5-12% without special difference. By considering the efficiency of composting in each of five treatments with pig manure the optimal water contents was about 57% level. Mixing a sawdust as a bulking agent was more positive than dried paper-mill sludge from a viewpoint of compost quality.

• Applied Biological Chemistry
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• v.26 no.2
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• pp.75-81
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• 1983

The performance of the flat-plate solar collector with rock-pile thermal storage medium and the drying characteristics of rough rice and red pepper by use of natural air and of supplementary heated air by the solar drier were studied. The thermal efficiency of the flat-plate solar collector was average 25.4 percent and the overall heattransfer coefficient of the collector was approximately $38.13kJ/hr.m^2^{\circ}C$. The flat-plate collector was able to supply the supplementary heated air which was about $7^{\circ}C$ higher than the ambient air temperature during the daytime and about $3^{\circ}C$ higher than during the night. For rough rice drying of grain moisture content front 24.5 to 14.5%, it took 18 days in the natural air system, 12 days in the tubular solar collector and 10 days in the flat-plate solar collector. For red pepper drying from it's moisture from 81.0 to 15.0%, 68 hrs required under conventional sun drying system, but 38 hrs in tubular solar collector and 36 hrs in the flateplate solar collector. The changes of capsanthin and capsaicine content were investigated at various drying system, and little difference was found among the drying system.

• Nuclear Engineering and Technology
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• v.49 no.5
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• pp.1044-1062
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• 2017

The construction project of the Kijang research reactor (KJRR), which is the second research reactor in Korea, has been launched. The KJRR was designed to use, for the first time, U-Mo fuel. Plate-type U-7 wt.% Mo/Al-5 wt.% Si, referred to as U-7Mo/Ale5Si, dispersion fuel with a uranium loading of $8.0gU/cm^3$, was selected to achieve higher fuel efficiency and performance than are possible when using $U_3Si_2/Al$ dispersion fuel. To qualify the U-Mo fuel in terms of plate geometry, the first miniplates [HANARO Miniplate (HAMP-1)], containing U-7Mo/Al-5Si dispersion fuel ($8gU/cm^3$), were fabricated at the Korea Atomic Energy Research Institute and recently irradiated at HANARO. The PIE (Post-irradiation Examination) results of the HAMP-1 irradiation test were analyzed in depth in order to verify the safe in-pile performance of the U-7Mo/Al-5Si dispersion fuel under the KJRR irradiation conditions. Nondestructive analyses included visual inspection, gamma spectrometric mapping, and two-dimensional measurements of the plate thickness and oxide thickness. Destructive PIE work was also carried out, focusing on characterization of the microstructural behavior using optical microscopy and scanning electron microscopy. Electron probe microanalysis was also used to measure the elemental concentrations in the interaction layer formed between the U-Mo kernels and the matrix. A blistering threshold test and a bending test were performed on the irradiated HAMP-1 miniplates that were saved from the destructive tests. Swelling evaluation of the U-Mo fuel was also conducted using two methods: plate thickness measurement and meat thickness measurement.