• Nuclear Engineering and Technology
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• 제41권4호
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• pp.493-520
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• 2009

During the last four decades, 16 Pressurized Water Reactors (PWR) and 4 Pressurized Heavy Water Reactors (PHWR) have been constructed and operated in Korea, and nuclear fuel technology has been developed to a self-reliant state. At first, the PWR fuel design and manufacturing technology was acquired through international cooperation with a foreign partner. Then, the PWR fuel R&D by Korea Atomic Energy Research Institute (KAERI) has improved fuel technology to a self-reliant state in terms of fuel elements, which includes a new cladding material, a large-grained $UO_2$ pellet, a high performance spacer grid, a fuel rod performance code, and fuel assembly test facility. The MOX fuel performance analysis code was developed and validated using the in-reactor test data. MOX fuel test rods were fabricated and their irradiation test was completed by an international program. At the same time, the PWR fuel development by Korea Nuclear Fuel (KNF) has produced new fuel assemblies such as PLUS7 and ACE7. During this process, the design and test technology of fuel assemblies was developed to a self-reliant state. The PHWR fuel manufacturing technology was developed and manufacturing facility was set up by KAERI, independently from the foreign technology. Then, the advanced PHWR fuel, CANFLEX(CANDU Flexible Fuelling), was developed, and an irradiation test was completed in a PHWR. The development of the CANFLEX fuel included a new design of fuel rods and bundles.. The nuclear fuel technology in Korea has been steadily developed in many national R&D programs, and this advanced fuel technology is expected to contribute to a worldwide nuclear renaissance that can create solutions to global warming.

• 한국대기환경학회지
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• 제16권5호
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• pp.521-528
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• 2000

Photocatalyzed degradation of trace level trichloroethylene(TCE) and toluene in air was carried out over near UV illuminated titanium doxide(anatase) pellet in a flow reactor. The authors investigaed the effects of humidity and trace contaminant levels on the oxidation rates of toluene. Inlet concentrations of TCE and toluene were 10∼100ppm. TCE photooxidation was very rapid under what conditions, and almost 100% conversion was achieved for TCE(up to 70 ppm) as a single air contaminant. An important finding was that competitive adsorption between humidity and trace contaminants has a significant effect on the oxidation rate of what.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 추계학술대회 논문집
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• pp.609-612
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• 2007

The co-combustion of coal and RPF(Refuse Plastic Fuel) mixture has been experimented in a commercially operating CFB coal boiler and the emissions such as SOx, NOx, TSP and dioxine were measured at the stack. The experimented RPF was supplied by domestic RPF company that is commercially producing RPF pellet from the wasted plastics. Up to 15% of total coal was substituted to RPF and no trouble was happened during normal boiler operation. SOx and NOx concentration was reduced about $15{\sim}20$% and TSP(Total Suspended Particle) was drastically reduced about 30% during co-combustion. Dioxine concentration at mixing ratio of 7.5% was $0.0487ng{\sim}TEQ/Sm^3$ ($O_2$, 12%) that satisfied governmental emission regulation.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.471-472
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• 2006

High aspect ratio of nano hairs on a plastic substrate is molded using thermoplstic materials including COC, PP, PC and PMMA. As a template for molding nano hairs, AAO membrane is adopted, which is 60um thick and 13mm in diameter. This membrane has about 109 of through-holes of which diameter is around 200nm. This AAO membrane and the pellet of materials are stacked in the mold and pressed to mold after heating up to be melted. The AAO membrane is removed using KOH to obtain the molded nano hairs. As a result, the diameter of the molded hairs is around 200nm and the length is $2um{\sim}60um$ depending on the molding conditions and materials.

• 혜화의학회지
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• 제10권1호
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• pp.67-78
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• 2001

From the study of acupuncture and external diseases on mammary diseases, the following conclusions are obtained. 1. Point Shanzhong, Shaoze and Rugen are often used for galactostasis in acupuncture. 2. Often used vessels for galactostasis in acupuncture are Stomach Meridian, Conception Vessel, Small Intestine Meridian, Bladder Meridian, Liver Meridian and Large Intestine Meridian in order. 3. The direct stimulations are used in external treatment for galactostasis, often accompanied by internal medical treatment, to promote the circulation of Qi and Blood. 4. Point Zuimup, Guangming of Gall bladder Meridian and Zusanli of Stomach Meridian is used for lactation pain in acupuncture. 5. Point Jianjing, Zusanli and Shanzhong are most often used for acuremastitis and breast cancer in acupuncture. 6. Often used vessels for acuremastitis and breast cancer in acupuncture are Stomach Meridian, Gall bladder Meridian, Conception Vessel, Small Intestine Meridian, Bladder Meridian, Pericardium Meridian in order. 7. The external treatment used for acuremastitis and breast cancer can be classed into its pathological period. When lactation is interrupted, Kumhwang Powder, Okro Powder, Robongbang, Allii Radix, Pinelliae Rhizoma, garlic moxibustion and Arusaenatus Rgizoma powder are used. When pus is piled up, Chunghwa Extracts, Dioscoreae Rhizoma, Leonuri Herba, Typa Latifolia, Taraxacum platycarpum, Phaseolus angularis, Manchong, Crvi Cornus latex, and Aucklandiae Radix are used. When pus flows down, Salviae Miltiorrhizae Radix Extract, nine-one pellet, Yongboo extract, eight-dampness extract, Tissue-regeneration Powder, Toad-net treatment, Kitten-hair, Hongseung pellet are used. 8. Stomach Meridian, Conception Vessel, Small Intestine Meridian, Gall Bladder Meridian, Bladder Meridian are most often used vessels for mammary diseases. From the conclusions above, It appears that the medical effect could be maximized by further studying and developing of the acupuncture and external treatment for mammary diseases according to the its nature, while accompanying internal medicine appropriately at the same time.

• 한국양식학회지
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• 제18권1호
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• pp.26-30
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• 2005

본 연구는 부상 건조사료와 습사료의 효능을 비교함과 동시에 이들 사료의 적정 공급률(만복 및 제한 공급)을 조사하기 위해 수행되었다 평균 체중 27 g의 넙치를 각 수조마다 500 마리씩 2반복으로 수용하여 부상 건조사료(EP1과 EP2)와 넙치용 분말사료(우성 사료)와 냉동 전갱이를 1:3의 무게 비율(습중량 기준)로 혼합하여 성형한 moist pellet (MP)을 만복 및 만복의 $85\%$로 공급하면서 10주간 사육하였다. 생존율은 모든 실험구에서 $94\%$ 이상이었으며, 증중량은 EP2를 만복 공급한 실험구가 가장 높았지만, EP1을 만복 공급한 실험구와 MP를 만복 및 제한 공급한 실험구들과는 유의한 차이가 없었다(P>0.05). 사료효율은 EPI과 EP2를 제한으로 공급한 실험구가 가장 높은 결과를 보였으며(P<0.05),동일한 사료 공급률에 있어 MP를 공급한 실험구가 EP1과 EP2를 공급한 실험구에 비해 유의적으로 낮은 결과를 보였다(P<0.05). 일일사료섭취율은 만복 및 제한 공급구 각각에서 MP를 공급한 실험구가 EP1 및 EP2을 공급한 실험구보다 유의하게 높았다(P<0.05). 단백질효율은 만복 및 제한 공급에 관계없이 MP를 공급한 실험구가 EPI 및 EP2를 공급한 실험구보다 유의하게 낮았다(P<0.05). 에너지 축적효율은 사료종류 및 공급률에 영향을 받지 않았다(P>0.05). 전어체의 수분, 단백질 및 회분의 함량은 모든 실험구에서 유의적인 차이를 보이지 않았다. 반면에 지질의 함량은 EP2와 MP의 만복 공급구에서 가장 높았고, EP1의 만복 공급구에서 가장 낮은 값을 보였다. 본 실험의 결과로부터, 본 연구에 사용된 EP 사료들은 현재 양식현장에서 사용하고 있는 생사료를 대체할 수 있을 것으로 생각되며, 사료는 만복으로 공급되는 것이 좋을 것으로 판단된다.

• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
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• pp.110-110
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• 2003

The high incidence of polyspermic fertilization is one of the major causes lowering the overall efficiency of porcine IVF. The common procedure for IVF involves the co-culture of both gametes in the medium drop, which increases sperm concentration and incidence of polyspermy. Therefore, the present study was carried out to increase the efficiency of porcine IVF by reducing polyspermy using a modified swim-up method. This method modifies conventional swim-up washing by placing oocytes directly at the time of washing. Sperm pellet was prepared in the tube and mature oocytes were placed on cell strainer with $70 \mu m$ pore size (Falcon 2350) at the top of the tube. After insemination, the oocytes were stained for examination. Also, the developmental potential of fertilized embryos was measured to evaluate for the feasibility of this method. While having similar penetration rates in both methods ($86.67 \pm 2.36% to 83.33 \pm 1.36%$), there was a significant reduction of polyspermy in modified swim-up method ($17.50 \pm 1.60%$) compare to the control ($44.1 \pm 3.70%$ (p<0.05). Subsequent culture showed higher rate of blastocyst formation in modified swim-up method (20.44$\pm$0.99%) than the control ($15.73 \pm 3.26%$) (P<0.05), even though there was no significant difference. These results suggest that, by controlling the number of spermatozoa reaching the oocytes, porcine oocytes might be protected from polyspermy in vitro. Also, the developmental potential of the fertilized embryos using this method could be improved by increasing the pool of spermatozoa with better quality. Further optimization of the procedure required to implicate this method in routine porcine IVF.

• 분석과학
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• 제19권5호
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• pp.407-414
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• 2006

An X-ray diffractometer for spatially resolved X-ray diffraction measurements was developed to identify phase in the narrow (micron-scaled) region of high burn-up fuels and some nuclear materials. The micro-XRD was composed of an X-ray microbeam alignment system and a sample micro translation system instead of a normal slit and a fixed sample stage in a commercial XRD. The X-ray microbeam alignment system was fabricated with a microbeam concentrator having two Ni deposited mirrors, a vertical positioner, and a tilt table for the generation of a concentrated microbeam. The sample micro translation system was made with a sample holder and a horizontal translator, allowing movement of a specimen at $5{\mu}m$ steps. The angular intensity profile of the microbeam generated through a concentrator was symmetric and not distorted. The size of the microbeam was $4,000{\times}20{\mu}m$ and the spatial resolution of the beam was $47{\mu}m$ at the sample position. When the diffraction peaks were measured for a $UO_2$ pellet specimen by this system, the reproducibility ($2{\Theta}={\pm}0.01^{\circ}$) of the peaks was as good as a conventional X-ray diffractometer. For the cross section of oxidized titanium metal, not only $TiO_2$ in an outer layer but also TiO near an oxide-metal interface was observed.

• 한국분말재료학회지
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• 제28권3호
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• pp.201-207
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• 2021

Ni-Cr-Al metal-foam-supported catalysts for steam methane reforming (SMR) are manufactured by applying a catalytic Ni/Al₂O₃ sol-gel coating to powder alloyed metallic foam. The structure, microstructure, mechanical stability, and hydrogen yield efficiency of the obtained catalysts are evaluated. The structural and microstructural characteristics show that the catalyst is well coated on the open-pore Ni-Cr-Al foam without cracks or spallation. The measured compressive yield strengths are 2-3 MPa at room temperature and 1.5-2.2 MPa at 750℃ regardless of sample size. The specimens exhibit a weight loss of up to 9-10% at elevated temperature owing to the spallation of the Ni/Al₂O₃ catalyst. However, the metal-foam-supported catalyst appears to have higher mechanical stability than ceramic pellet catalysts. In SMR simulations tests, a methane conversion ratio of up to 96% is obtained with a high hydrogen yield efficiency of 82%.

• 한국양식학회지
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• 제18권1호
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• pp.31-36
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• 2005

본 연구는 겨울철 넙치 사육시 부상 배합사료의 적정 공급횟수와 공급률을 조사하기 위해 평균 체중 45.0 g의 넙치를 각 수조마다 20마리씩 3반복으로 수용하여 60일간 사육하였다. 사료 공급횟수는 1일 3회, 1일 2회, 1일 1회 및 2일 1회로 설정하였으며 사료 공급량은 만복 및 만복의 $80\%$로 설정하였다. 생존율은 모든 실험구에서 $96\%$이상이었으며, 증중량은 1일 2회 만복 공급구가 1일 3회 공급구와 통계적인 차이는 없었지만 가장 높았고. 2일 1회 제한 공급구가 가장 낮은 결과를 보였다. (P<0.05). 그리고 동일한 공급횟수에서 만복 공급구가 제한 공급구보다 높은 성장을 보였다. 일일사료섭취율은 만복 공급구와 제한 공급구 모두 공급횟수가 증가할수록 증가하다가 1일 2회 공급구 이상에서는 유의한 차이가 없었다. 사료효율과 단백질효율은 1일 3회 제한 공급구가 가장 높았고 2일 1회 제한 공급구가 낮은 값을 보였으며(P<0.05), 나머지 실험구들 사이에는 유의한 차이를 보이지 않았다. 사육 실험 종료시 전어체의 수분, 단백질, 지질 및 회분함량은 모든 실험구간에 유의한 차이가 없었다. 이상의 결과로부터, 평균체중 45-53 g의 넙치치어를 겨울철에 사육할 때는 부상배합사료를 1일 2회 만복으로 공급하는 것이 바람직 할 것이라 판단된다.