• 한국정밀공학회지
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• 제17권1호
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• pp.145-152
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• 2000

X-ray diffraction method detects change of crystal lattice distance under material surface using diffraction angle 2$\theta$. This technique can be applied to the behavior on slip band and micro crack due to material degradation. The relation between half-value breadth and number of cycle has three stages which constitute rapid decrease in initial number of cycles, slight decrease in middle number of cycles and rapid decrease in final number of cycles. The ratio of half-value breadth takes a constant value on B/B$_{0}$-N diagram with loading condition except early part of fatigue life. The ratio of half-value breadth B/B$_{0}$ with respect to number of cycle to failure N$_{f}$ has linear behavior on B/B$_{0}$-log N$_{f}$ diagram. Therefore, in this paper the estimation of fatigue life by average gradient method has much less estimated mean error than the estimation of fatigue life by log B/B$_{0}$-log N/N$_{f}$ relation.elation.ation.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 1997년도 International Symposium on Fire Science and Technology
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• pp.138-145
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• 1997

Models of upward flame spread have been attempted in the past, but in the current work an emphasis has been placed on developing a practical model that will be useful across a broad range of materials. Some of the important aspects of the model we: the addition of external radiation to simulate a wall that is a part of an enclosure fire and has flaming walls radiating to it, the use of a correlation for flame heat feedback distribution to the sample surface based on data available in the literature, and the use of an experimentally measured mass loss rate for the sample material, In this paper, the development of the numerical model is presented along with predictions of flame spread for three materials: hardboard, a relatively homogeneous wood-based material; plywood, which is made of laminated wood bonded by adhesives; and a composite material made of fiberglass matrix embedded in epoxy. Predictions are compared with measured data at several levels of external radiation for each material. For the materials tested, the model correctly predicts trends and does a reasonable job predicting flame heights. The need for thermal property data for practical materials, which would be appropriate for flame spread models, is indicated by this work.

• 한국기계기술학회지
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• 제13권2호
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• pp.145-153
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• 2011

The irradiation tests of materials in HANARO have been performed usually at temperatures below $300^{\circ}C$ at which the RPV(Reactor Pressure Vessel) materials of the commercial reactors such as the light water reactor and CANDU are operated. As VHTR(Very High Temperature Reactor) and SFR(Sodium-cooled Fast Reactor) projects are being carried as a part of the present Gen-IV program in Korea, the requirements for irradiation of materials at temperatures higher than $500^{\circ}C$ are recently being gradually increased. To overcome the restriction in the use at high temperature of the existing Al thermal media, a new capsule with double thermal media composed of two kinds of materials such as Al-Ti and Al-graphite was designed and fabricated more advanced than the single thermal media capsule. At the irradiation test of the capsule, the temperature of the specimens successfully reached $700^{\circ}C$ and the integrity of Al, Ti and graphite material was maintained.

• Journal of Magnetics
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• 제18권1호
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• pp.30-33
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• 2013

The magnetocaloric effect and magnetization behavior have been analyzed in the double-perovskite $La_{0.7}Ba_{0.3}Mn_{1-X}Fe_XO_3$ compound with the sintering temperature at 1273 K. Samples were fabricated by the conventional solid-state reaction method. X-ray diffraction measurement revealed that all the samples had a single phase in orthorhombic. Detailed investigations of the magnetic entropy behavior of the samples were discussed with the variation of $T_C$. The magnetic entropy changes, ${\Delta}S_M$ of approximately 0.36-1.14 J/kg K were obtained in the temperature range of 145-350 K for the $La_{0.7}Ba_{0.3}Mn_{1-X}Fe_XO_3$ compound. The enhancement of the magnetic entropy change is believed to be due to changes in the microstructure, which changes the magnetic part of the entropy of a solid around the magnetic ordering temperature.

• Ocean and Polar Research
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• 제44권2호
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• pp.139-145
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• 2022

Manganese nodules were recovered within the deep subseafloor sediments (118.22 mbsf) at Site U1371 during International Ocean Discovery Program (IODP) expedition 329 from the South Pacific Gyre (SPG). Because most manganese nodules exist on the seabed surface, nodules present in deep sediments are uncommon. Therefore, the growth origin of manganese nodules was identified through mineralogical and geochemical analyses. The manganese nodule was divided into the concentric layer outside the manganese region and the inner part of the phosphatized region consisting of manganese oxide minerals and carbonate fluorapatite (CFA) minerals, respectively. The two-dimensional element distribution analysis of Mn, Co, Ni, Sr and Cu, Zn with low Mn/Fe ratio confirmed that manganese nodules were formed predominantly by a hydrogenetic process and a biogenic process in certain manganese layers. As a result, the manganese nodule was continuously precipitated in SPG environments of oligotrophic open paleoocean conditions and rapidly buried with siliceous ooze sediments when the SPG changed to a eutrophic environment. It has been confirmed that manganese nodules found within deep subseafloor sediments could be used as a new proxy for the reconstruction of paleooceanographic conditions.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 가을 학술논문 발표대회
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• pp.145-146
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• 2022

The demand for a construction method capable of securing a safety environment and improving quality is increasing. There is a high risk of falling when working at a high place in an environment where it is difficult to secure visibility, such as an underground space, and there is a risk of falling if cement liquid waterproof materials are transferred to the top of the scaffold by manpower. In addition, when working on a high place in a poor environment, the quality uniformity of the upper part of the wall is deteriorated. In addition, as waterproof technicians gradually age and decrease, it is difficult to secure them, so it is urgent to prepare countermeasures against the shortage of waterproof technicians. Therefore, the purpose of this study is to develop cement liquid waterproof spouting construction equipment that can secure uniform quality of construction areas to prevent accidents and ensure safety of workers, improve work efficiency and quality due to improvement of work environment. The adhesion performance of the cement liquid waterproof material could be improved by about 20% in accordance with the use of the equipment.

• Journal of Animal Science and Technology
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• 제53권1호
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• pp.59-66
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• 2011

본 조사연구는 2008년 1년간 우리나라 253개 양봉농가의 설문 조사를 통하여 경영형태를 분석하고 기술 및 기반수준을 평가하여 농가의 생산성 향상을 위한 새로운 경영지표 설정에 필요한 기초적 자료를 얻고자 실시하였다. 그 결과를 요약하면 다음과 같다. 양봉농가의 평균 봉군관리 수는 145.89군으로 조사되었다. 관리자의 연령별로는 통계적 유의성(p<0.05)이 인정되었는데 55세 미만 연령그룹에서 평균 191.68군으로 가장 많이 사육하고 있었으나, 연령이 많을수록 봉군 수는 적게 관리하는 것으로 나타났다. 경력 별로도 고도로 유의한 차이(p<0.01)를 보였는데, 15년 이상 고경력 농가에 평균 175.96군을 사육하고 있었으며, 경력이 높은 농가에서는 더욱 많은 봉군을 관리하고 있었다. 거주지별과 학력별간 모두 각각 유의한 차이가 없었다. 그러나 경영형태별로는 고도로 유의한 차이(p<0.001)가 인정되었는데 고정양봉은 평균 82.99군 이었으나 이동양봉은 220.18군을 경영관리하고 있었다. 양봉장은 농가주변(57.8%)에서 가장 많이 위치하고 있었으며, 그 다음은 산간지(30.3%)에서 양봉하고 있는 것으로 조사되었다. 연령별 양봉장의 위치 분석에서는 유의한 차이(p<0.05)가 있었는데, 산간지는 젊은 연령층(36.9%)에서 많이 사육하는 반면에 농가주변은 노년층(65.4%)에서 주로 많이 사육하는 것으로 나타났다. 거주지별 분석에서도 고도로 유의한 차이(p<0.001)가 인정되었는데 산간지(40.0%)에서는 산간마을 거주자가 많이 사육하고 있는 반면에 농가주변에서는 산간마을이나 중소마을 거주자 서로 모두 비슷하게 사육하고 있었다. 그러나 경력별, 학력별 및 형태별간에는 모두 유의한 차이가 없는 것으로 나타났다. 조사된 양봉농가는 부업고정양봉(35.7%)으로 경영하는 경우가 가장 많았다. 연령층별간에는 고도로 유의한 차이(p<0.01)를 보였는데, 젊은 연령그룹에서는 전업이동양봉(38.8%)을 가장 많이 하는 것으로 나타났으나 노년층에서는 부업고정양봉(43.2%)을 주로 경영하고 있었다. 경력별로도 고도의 유의성(p<0.001)이 인정되었는데, 저경력 층에서는 부업 고정양봉(46.6%) 경영이었으나 고경력 층 그룹은 전업 이동양봉(40.3%)을 하고 있는 것으로 나타났다. 그러나 거주지별간에는 유의한 차이가 없는 것으로 나타났다. 양봉농가는 벌꿀은 물론 프로폴리스, 종봉 분양, 화분, 로열 젤리, 매개봉군 순으로 양봉 생산물을 생산하는 것으로 조사되었다. 15년 이하 저경력 층은 주로 프로폴리스, 화분 등을 생산한 반면에 고경력 층에서는 주로 프로폴리스, 분양 종봉 등을 생산하는 것으로 나타났다. 산간마을 양봉 농가는 주로 프로폴리스, 화분 등을 얻고 있으나, 중소마을 양봉 농가는 프로폴리스, 분양 종봉 등을 생산하는 것으로 나타났다. 그리고 고정과 이동양봉농가 모두 프로폴리스, 화분 등을 주로 많이 생산하는 것으로 조사되었다. 양봉농가 기술보유 수준 및 기반수준은 5점만점 중 각각 평균 3.11점과 2.86점으로 모두 중등수준으로 평가되었다. 경력별간에는 기술수준이나 기반수준 모두 고도로 유의한 차이를 보였는데, 저경력보다 고경력 농가에서 기술수준 평균3.33점과 기반수준 평균 3.02점으로 더 높게 평가되었다. 그러나 연령층간이나 거주지간의 기술수준이나 기반수준평가 모두 서로 비슷한 경향을 보였다.

• 한국제4기학회지
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• 제17권2호
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• pp.145-148
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• 2003

The Kunang cave paleolithic site is located at Tanyang [$N37^{\circ}2'$, $128^{\circ}21'E$], Chungbuk Province, which is in the Central part of the Korean peninsula. The cave is developed at 312 amsl in a karstic mountainous area. The South Han River flows across this region and other caves can also be found near the river. The site was discovered in 1986 and excavated 3 times by the Chungbuk National University Museum until now. The cave was wellpreserved from modem human activities until the first discovery. The full length of the cave is estimated to be ca. 140 m. However, a spacious part up to 11 m from the entrance has been excavated. Eight lithological units are divided over the vertical profile at a depth of 5 m. Each unit is deposited in ascending order as follow: mud layer (Unit 9), lower complex (Unit 8) which is composed of angular blocks and fragments with a muddy matrix, lower travertine layer (Unit 7； flowstone), middle complex (Unit 6; cultural layer) which is composed of fragments with a muddy matrix, middle travertine layer (Unit 5； flowstone), yellowish muddy layer (Unit 4), upper complex (Unit 3； cultural layer) which has a similar composition to Unit 8. the upper travertine layer (Unit 2； flowstone), and finally surface soil layer (Unit 1). The most abundant vestiges in the cultural layers are the animal bones. They are small fractured pieces and mostly less than 3 cm in length. About 3,800 bone pieces from 25 animal species have been collected so far, 90 percent of them belonging to young deers. Previous archaeological study of these bone pieces shows thatprehistoric people occupied the cavenot for permanent dwelling but for temporary shelter during their seasonal hunting activity. More extensive studies of these bones together with pollen analysis are in progress to reconstruct the paleoenvironment of this cave. Only a single date (12,500 BP) obtained from a U-Th measurement of the upper travertine layer was previously available. In spite of the importance of the cave stratigraphy, there was no detail chronological investigation to establish the depositional process of the cultural layers and to understand the periodic structure of the cave strata, alternating travertine floor and complex layers. We have measured five 14C age dating (38900+/-1000, 36400+/-900, 40600+/-1600, more than 51000 and 52000 14C BP) using Seoul National University 14C AMS facility, conducted systematic process of the collagen extraction from bone fragments samples. From the result, we estimate that sedimentation rate of the cave earth is constant, and that the travertine layers, Unit 2 and Unit 3, was formed during MIS 5a(ca. 80 kBP) and MIS 5c (ca. 100 kBP) respectively. The Kunang Cave site is located at Yochonli of the region of Danyang in the mid-eastern part of Korea. This region is compased of limestones in which many caves were found and the Nam-han river flows meanderingly. The excavations were carried out three times in 1986, 1988, and 1998.

• 대한정형도수물리치료학회지
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• 제10권1호
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• pp.129-145
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• 2004

Many physical therapy who graduate department of physical therapy interested in physical therapy specialist. The boundary of physical therapy specialist is consist of 7 parts; CCS(Cardiopulmonary Certified Specialist), ECS(Clinical Electrophysiologic Certified Specialist), GCS(Geriatric Certified Specialist), NCS(Neurologic Certified Specialist), NCS(Neurologic Certified Specialist), OCS(Orthopaedic Certified Specialist), PCS(Pediatric Certified Specialist), SCS(Sports Certified Specialist). So the purpose of this study was to investigate of undergraduate student's interest about the area of special physical therapy and its academy. The data were collected from May 17 to 24, 2004 and 158 valid questionnaires were obtained and analyzed. It was for undergraduate students who major in physical therapy in college and university which are located in Busan, Ulsan and Kyoungnam province. The result is follows: 1. The research about the study of physical therapy after graduation was that 45.5% of female thought that they going to study as possible as they can was the best. In the case of men, 54.3% of male thought that they going to study was the best. 2. The result about recognition of special physical therapy was that 62.0% of people answered CCS, 69.6% of people answered GCS. The most familiar part of special physical therapy at course of school curriculum was that 88.0% of people answered OCS, and 84.2% of people answered NCS. 3. The result about the most interesting part of special physical therapy was that 68.6% of male and 36.1% of female answered OCS. On the other hand, the least part that people doesn't care was that 41.2% of male answered PCS, and 41.0% of female answered CCS. 4. About educational matters of special physical therapy and its academy was that 60% of answered 'Not enough'. An answer to question of special physical therapy and its academy's educational necessity. At the a course of faculty and clinical practice was that 58.9% of answered 'somewhat necessary'. After graduation, study a plan of special physical therapy was that 59.5% of answered 'immediate academy'. 5. Recognize scale in alternation physical therapy, think of extend physical therapy's territory is 'necessary of extend territory' was 78% the highest answer. 57.6% of answered was concerned about alternating physical therapy, and want to study.

• Journal of Pharmaceutical Investigation
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• 제33권2호
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• pp.145-149
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• 2003

Manufacturing facilities of the pharmaceuticals must meet certain level of the cleanness required so that foreign substances such as dust, moisture, heat, microorganism, or virus do not contaminate the product. In case of radiopharmaceuticals for medical treatment and diagnosis, not only should the operators and environment be protected from radiation but also need to be isolated from the foreign contaminant. Therefore, manufacturing facilities for radiopharmaceuticals must satisfy the design standards of both hot cell and clean room which are specified by GMP. However, standards of maintaining negative pressure for preventing spread of radioactive contaminant in isolated facilities conflict with the standards of maintaining positive pressure for keeping cleanness. To solve this problem, air pressure of hot cell was designed lower than in the adjacent area to meet standards of the radiation safety. To keep higher cleanness in certain part of the hot cell for filling, minimal relative positive pressure allows. In order to effectively maintain the cleanness that is required for production of Tc-99m generator, which takes 70% of whole demand of radiopharmaceuticals, the rooms placed in each side of production room are used as a buffer area and three lead hot cells are installed in production room. In this research, we established the appropriate engineered design concept for Tc-99m generator manufacturing facility, which satisfies both GMP cleanness standard for preventing particles, bacteria, other contaminants and the regulations of radiation safety for supervising and controlling the amount of radiation exposure and exhausted radioactivity. And the concept of multi-barrier buffer zones is introduced to apply negative air pressure for hot cell with first priority and to continue relative positive air pressure for clean room.