• Journal of the Korean Solar Energy Society
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• v.30 no.6
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• pp.16-21
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• 2010

It is well-known that Boron-doped Cz Si solar cells suffer light-induced degradation due to boron-oxygen defect which is responsible of a reduction in lifetime and hence efficiency. In this paper, we assume that PV solar cell has been connected with variable load to account the real operating condition and it shows different light-induced degradation of Si solar cell. To evaluate the effect of light-induced degradation for solar cell with various load, Single crystalline solar cells are connected with open and short circuits during light exposure. Isc-Voc curve evaluate light induced degradation of solar cells and the reason is explained as a change for serial resistance. From the results, Electrical characteristics of solar cells show better performance under short circuit conditions, after light exposure.

• Nuclear Engineering and Technology
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• v.34 no.3
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• pp.187-201
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• 2002

The KN-12 cask is designed to transport 12 PWR spent nuclear fuels and to comply with the requirements of Korea Atomic Energy Act, IAEA Safety Standards Series No.57-1 and US 10 CFR Part 71 for a Type B(U)F package. It provides containment, radiation shielding, structural integrity, criticality control and heat removal for normal transport and hypothetical accident conditions. W.H 14$\times$14, 16$\times$16 and 17$\times$17 fuel assemblies with maximum allowable initial enrichment of 5.0 wt.%, maximum average burn-up of 50,000 MWD/MTU and minimum cooling time of 7 years being used in Korea will be loaded and subsequently transported under dry and wet conditions. A forged cylindrical cask body which constitutes the containment vessel is closed by a cask lid. Polyethylene rods for neutron shielding are arranged in two rows of longitudinal bore holes in the cask body wall. A fuel basket to accommodate up to 12 PWR fuel assemblies provides support of the fuels, control of criticality and a path to dissipate heat. Impact limiters to absorb the impact energy under the hypothetical accident conditions are attacked at the top and at the bottom side of the cask during transport. Handling weight loaded with water is 74.8 tons and transport weight loaded with water with the impact limiters is 84.3 tons. The cask will be licensed in accordance with Korea Atomic Energy Act 3nd fabricated in Korea in accordance with ASME B&PV Code Section 111, Division 3.

• Conservation Science in Museum
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• v.4
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• pp.57-61
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• 2003

From the stupa of Sujongsa-Temple, located in Yangpyeong, Gyeonggi-do province, was excavated a celadon jar with lid, a gilt-bronze nine-storied miniature pagoda and a silver-plate hexagonal miniature shrine, etc. Among them, the gilt-bronze miniature pagoda has been known as a gilt-bronze product since most of its surface has copper tint and the base part has bronze corrosion. Its formal title registered on the Cultural Properties Administration also begins with "a gilt-bronze". However, it was supposed to be a gold product in many aspects: the color and status of the surface, degree of the bronze corrosion creation and the metal thread joining the wind bell. So the necessity to prove its material by a scientific analysis was raised. We examined it with nondestructive method. The results were traces of open-working on many parts of the surface, but no traces of gilding. Moreover, as we perform an XRF analysis, the main component were gold and silver(16%) and some impurities such as copper and iron were found. Therefore, it could be inferred that this miniature pagoda is a gold product.

• Microbiology and Biotechnology Letters
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• v.31 no.4
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• pp.311-321
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• 2003

Bacteria produce lipases, which can catalyze both the hydrolysis and the synthesis of long chain triglycerides. These reactions usually proceed with high regioselectivity and enantioselectivity, and, therefore, lipases have become very important biocatalysts used in organic chemistry. 3D lipase structures were solved from several bacterial lipases. They have an $\alpha/\beta$ hydrolase fold and a catalytic triad consisting of a nucleophilic serine, and an aspartate or glutamate residue that is hydrogen bonded to a histindine. Active sites are covered with $\alpha$-helical lid structure, of which movement is involved in the enzyme's activation at oil/water interface. Four substrate binding pockets were identified for triglycerides: an oxyanion hole and three pockets accommodating the fatty acids bound at positions sn-1, sn-2, and sn-3. These pockets determine the enantiopreference of a lipase. The understanding of structure-function relationships as well as the development of molecular evolution techniques will enable researchers to tailor new lipases for biotechnological applications.

• Resources Recycling
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• v.19 no.1
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• pp.13-20
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• 2010

Much energy is consumed up when making a concrete. And especially, because lots of $CO_2$ is discharged for combination material, cement, we are making efforts in order to get lid of this negative thought. Recently, much interest is given to manufacturing eco concrete which is environment friendly and its' application. We should study manufacturing of the concrete whose environment friendly performance should be improved as consistent development concept in order for various approaches to be settled down our country such as lowering of environmental load, utilization of industry wastes and improvement of environment related performance. This study inquired into utilization possibility through from various tests results after manufacturing eco type mixed concrete whose purpose is to lower environmental load in which cement and aggregates can be replaced with metakaolin which is natural material and copper slag which is industry by product.

• Journal of Biosystems Engineering
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• v.30 no.5 s.112
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• pp.261-267
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• 2005

In order to save labor and cost, direct seeding has been considered as an important alternative to the machine transplanting in rice cultivation. As current seeders for direct seeding of rice seeds drill irregular amount of seeds under various operating conditions, conventional drilling should be turned to precision planting which enables accurate placement of proper amount of rice seeds at equal intervals within rows. In this study, design, construction and performance evaluation of a precision seed metering device for planting of rice seeds were carried out. As prototype, the conventional roller type seed metering device was modified for planting: increasing diameter of metering roller, setting 2 or 4 seed cells on metering roller, adding seed discharging lid and its driving cam mechanism. Through performance tests for prototype and the current seed metering device, number of seeds in a hill, planting space and its error ratio, coefficient of variation of planting space (planting accuracy), and seeding length of $90\%$ of seeds in a hill divided by planting space (planting precision) at setting planting spaces of 15, and 20cm, seeding heights of 10, and 20cm, and seeding speeds of 0.1, 0.2, and 0.5m/s were investigated. Prototype showed better seed planting performance than the current seed metering devices. When setting planting space of 15 cm and seeding height of 10cm, prototype with 2 seed cells showed that variations of planting space and seeding lengths of $90\%$ of seeds in a hill at up to seeding speed of 0.5m/s were within 0.9cm, and 3.6cm, respectively.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1326-1330
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• 2000

Kimchi, made from seasonal baechu (Chinese cabbage), was sealed in PP trays with a Nylon/CPP lid film and stored at various temperatures (0, 10, $20^{\circ}C$) to investigate the feasibility of detecting its fermentation degree by measuring gas composition inside the packages. The gas composition inside the kimchi package continuously changed due to $CO_2$ evolution during fermentation. Regardless of temperature, the fermentative gas accumulation in the package caused $CO_2$ concentration to increase by two-stepwise pattern, but $O_2$ concentration to decrease exponentially. As $CO_2$ concentration increased secondarily, the pH values of kimchi decreased proportionally (r>0.968). The production of $CO_2$ during kimchi fermentation was stimulated at higher temperatures and affected by seasonal factor. Kimchi made from winter baechu produced more fermentative gas than that from summer baechu. It was suggested that the changes in $CO_2$ concentration could be used as a characteristic index for indicating the fermentation course of packaged kimchi products.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.654-661
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• 2017

Recently, a low-impact development (LID) technic such as a wetland has been proposed as a Nature-friendly process for reducing pollutants caused by livestock wastewater. Therefore, the Daphnia magna toxicity was analyzed for livestock wastewater samples, to determine if a wetland system would also be effective in reducing this ecotoxicity. In the present study, acute D. magna toxicity was not significantly dependent on the presence and type of reed, nor type of media. However, when treated with construction wetlands, ecotoxicities decreased as well as TN, TP and COD concentrations. Therefore, it is considered that a construction wetland system with bio reeds and bio-media as well as general reeds would be effective to reduce the ecotoxicity of livestock wastewater. To apply a wetland system as the subsequent treatment process to a livestock waste water treatment facility, it is necessary to perform an integrated evaluation such as treatment efficiency and the ecotoxicity test for various characteristics of livestock wastewater.

• Journal of Biomedical Engineering Research
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• v.27 no.4
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• pp.154-163
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• 2006

A 64-channel magnetocardiogram (MCG) system using low-noise superconducting quantum interference device (SQUID) planar gradiometers was developed for the measurements of cardiac magnetic fields generated by the heart electric activity. Owing to high flux-to-voltage transfers of double relaxation oscillation SQUID (DROS) sensors, the flux-locked loop electronics for SQUID operation could be made simpler than that of conventional DC SQUIDs, and the SQUID control was done automatically through a fiber-optic cable. The pickup coils are first-order planar gradiometers with a baseline of 4 em. The insert has 64 planar gradiometers as the sensing channels and were arranged to measure MCG field components tangential to the chest surface. When the 64-channel insert was in operation everyday, the average boil-off rate of the dewar was 3.6 Lid. The noise spectrum of the SQUID planar gradiometer system was about 5 fT$_{rms}$/$\checkmark$Hz at 100 Hz, operated inside a moderately shielded room. The MCG measurements were done at a sampling rate of 500 Hz or 1 kHz, and realtime display of MCG traces and heart rate were displayed. After the acquisition, magnetic field mapping and current mapping could be done. From the magnetic and current information, parameters for the diagnosis of myocardial ischemia were evaluated to be compared with other diagnostic methods.

• Aerospace Engineering and Technology
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• v.7 no.1
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• pp.83-90
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• 2008

The next generation LID satellite has 64KB PROM which contains the boot loader and the monitor software, and two 4MB NVMEMs which are used for flight software storage. The boot loader has two operation modes which are the flight software mode and the monitor mode. In the flight software mode, it checks CRC checksum of selected NVMEM and copies flight software image from NVMEM to RAM And then it starts VxWorks RTOS in RAM, creates flight software tasks, and starts execution of flight software. In the monitor mode, it activates monitor software which performs NVMEM reprogramming and board-level testing on the ground. This paper is to present the design of Boot ROM software and verification method using simulator.