• Journal of the Korean Society for Heat Treatment
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• v.31 no.3
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• pp.135-142
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• 2018

In this study, we have fabricated n-type $Bi_2Te_{2.85}Se_{0.15}$ compounds by different processing routes such as crushing, milling and mixing respectively. Subsequently, the obtained powders were consolidated by spark plasma sintering (SPS). The phase crystallinity of bulk samples were identified using X-ray diffraction technique. Powder morphology and fracture surface of bulk samples were observed using the scanning electron microscopy (SEM). The Seebeck coefficient and electrical conductivity values were significantly increased for the milling sample than crushing and mixing samples. As a result, the maximum power factor was obtained $2.4mW/mK^2$, which is thrice than that of crushing process. The maximum figure of merit (ZT) of 0.77 was achieved at 400 K for the milling sample. Furthermore, relatively high hardness and density values were noticed for the different processed samples.

• Applied Chemistry for Engineering
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• v.4 no.3
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• pp.497-504
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• 1993

The effect of DCCA (Drying Control Chemical Additives) on the drying of gel was investigated in order to determine an optimum drying condition of mullite precursor through sol-gel process. Aluminium sec-butoxide was synthesized from aluminium foil and then mullite powders were synthesized from Tetra-ethyl-ortho-silicate (TEOS) and the aluminium sec-butoxide. N, N-dimethyl formamide (DMF), Glycerol, 1, 4-Dioxane, and Oxalic acid were used as DCCA. Mullite powders that were calcined at 200, 900, 1100, and $1250^{\circ}C$ for 2hr were analysed by XRD, TG-DTA, FT-IR, and SEM in order to investigate structural change and characteristics of calcined powders. The results of this work showed that the drying time of gel was reduced to about half in the presence of 0.1mol DMF compared with the absence of DCCA and also calcined powders were obtained without remarkable structural change despite of the addition of DCCA.

• Proceedings of the Korean Vacuum Society Conference
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• 2015.08a
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• pp.255-255
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• 2015

국제핵융합실험로(ITER)의 3대 목표 중 하나는 핵융합로 개발을 위한 삼중수소증식블랑켓 개념을 시험하고 검증하는 것이며, 이를 위해 시험증식블랑켓(TBM, Test Blanket Module) 프로그램을 마련, 각국이 참여할 수 있도록 하고 있다. 한국도 2012년 국가핵융합위원회 결정에 따라, EU, 일본, 중국, 인도와 함께 TBM 프로그램에 참여하고 있으며, 2021년 설치를 목표로 헬륨냉각 고체증식재 개념의 HCCR (Helilum Cooled Ceramic Reflector) TBM을 설계, 개발하고 있다. 한국형 TBM은 총 4개의 서브모듈과 하나의 후벽(Back Manifold, BM) 으로 구성되며, 각 서브모듈은 플라즈마와 대면하는 일차벽(First Wall, FW), 증식재와 증배재, 반사재를 담고 있는 증식영역(Breeding Zong, BZ), 냉각재 매니폴드 및 구조물 역할을 하는 측벽(Side Wall, SW) 등의 기능부품으로 구성되어 있다. 냉각재는 8 MPa, $300-500^{\circ}C$의 고온고압헬륨을 사용하고, Li2SiO4 혹은 Li2TiO4 형태의 Li 세라믹 증식재를 사용하며, 중성자 증배를 위해 Be 증배재 및 흑연 반사재를 사용한다 [1-3]. 2015년 2월 개념설계검토(CDR, Conceptual Design Review)를 위해, TBM-shield를 포함한 TBM-set 설계가 완료되었으며, 열수력, 구조, 지진, 전자기, 복합하중에 대한 평가가 진행되었다. 본 논문에서는 이 중 H/He-phase에 시험될 EM-TBM과 D-T phase에 시험될 INT-TBM에 대한 열수력 성능 결과를 소개하였다[5]. 각각의 열부하 조건은 0.17과 $0.3MW/m^2$이며, 중성자 조사는 D-T phase 에서만 고려되었다. 구조재 및 사용된 기능소재별 온도 요건을 정의하고, 성능해석 결과와 비교하였으며, 이를 통해 모든 온도 요건을 만족함을 최종 확인하였다. 이러한 온도 분포는 열응력 평가를 위해 구조해석 입력자료로 활용되었다.

• Restorative Dentistry and Endodontics
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• v.29 no.5
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• pp.454-461
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• 2004

The purpose of this study is to compare and to evaluate the effects of the degree of saturation on the progression of artificial root caries lesion. A total of 8 human premolars without any defects and cracks selected and the cementum were removed and the teeth were cleaned with ultrasonic device and pumice without fluoride. Each tooth was sectioned into 6 pieces and they were ground with #800 sandpaper until they had a thickness of 200pm. Specimens were applied with nail vanish except for the 2-3 mm window area after application of bonding agent. Under the constant pH, the specimens were divided into 6 groups (degree of saturation: 0.1415, 0.1503, 0.1597, 0.1676, 0.1771. 0.1977). Each group was immersed in acid buffer solution for 1. 2, 3, 5 days under controlled temperature ($25^{\circ}C$) and imbibed in water and examined using the polarizing microscope. The results were as follows 1. Although the degree of saturation of demineralization solution decreased, the depth of penetration in the dentin was constant. 2. Erosion was observed on the surface of all the teeth in the group I, II. In the group III, IV, V, surfaces were not changed. The teeth in the group VI showed the more mineralized surface but not the shape of the dentinal tubules distinctively. 3. In all groups, the lesion progressed rapidly at the first day of the experiment, but increased gradually as time elapsed.

• Applied Biological Chemistry
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• v.35 no.3
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• pp.157-164
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• 1992

In order to produce nicotinamide adenine dinucleotide (NAD) which is a pyridine nucleotide coenzyme, Saccharomyces sake KBA No. 6 having high NAD content was selected from 12 strains of yeast and various factors affecting the production of NAD were investigated. For NAD production, 4% of glucose was effective as a carbon source and 2% of bactopeptone was the best nitrogen source. The optimum pH and temperature was 5.0 and $30^{\circ}$, respectively. Also, when 4 mg/ml of nicotinamide and 3 mg/ml adenine were used as precursors simultaneously, NAD production was the best. To increase NAD production, 2 valence metal ions were used during cultivation and $Zn^{2+}$ was very efficient. Among the surface active agents, anionic sodium dodesyl sulfate (SDS) was effective. Under the optimum conditions, the maximum amount of produced NhD was 35 mg/100 ml medium after cultivation of 144 hrs and 89% of total NAD amount, 31 mg of NAD, was leaked into culture broth.

• Korean journal of applied entomology
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• v.22 no.3 s.56
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• pp.198-202
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• 1983

A mosaic disease of gladiolus has been commonly observed with an infection rate of $43.3\%$ in the field. Bean Yellow Mosaic Virus(BYMV) produced veinal spreading lesions on Cheonopodium amaranticolor, veinal necrosis and severe leaf distortion on Phaseolus vulgaris 'Scotia' and mosaic on Vi cia faba. Cucumber Mosaic Virus(CMV) produced local lesions on C. amaranticolor, mosaic symptoms on Nicotiana glutinosa and Cucumis sativus. BYMV and CMV were transmitted by the green peach aphid. Purified BYMV and CMV had a typical maximum absorption at 260nm. In agar gel diffusion test, BYMV and CMV gave positive reaction with their homologous antiserum. The size of BYMV was 750nm in length, and CMV was 30nm in diameter.

• Journal of Environmental Science International
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• v.11 no.6
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• pp.489-496
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• 2002

The purpose of this study was to investigate spatial distributions of total deposition. A total number 79 samples were collected at 17 sampling sites from September 1999 to January 2000. Total (=wet+dry) atmospheric depositions were collected by filtered deposition sampler at sampling site (the Western Part of Kyongsangnam Province). In addition, the deposition of soluble and insoluble fraction was also investigated to find a suitable simplified collection method for a long-term monitoring of total deposition. The total depositions were measured soluble amount(mm/month), insoluble amount(kg/km$^2$/month), pH, conductivity(E.C.) and eight ionic components. The spatial distribution of deposition flux was to estimated by using a kringing analysis. The 17 sites mean fluxes of water soluble ionic components; SO$_4$$\^$2-/, Cl$\^$-/, NO$_3$$\^$-/, Na$\^$+/, NH$_4$$\^$+/, K$\^$+/, Mg$\^$2+/, Ca$\^$2+/ were 100.7∼315.6kg/km$^2$/month, 30.1∼234.3kg/km$^2$/month, 64.4∼ 139.4kg/km$^2$/month, 7.5∼68.3kg/km$^2$/month, 10.7∼48.7kg/km$^2$/month, 5.6∼27.9kg/km$^2$/month, 4.5∼17.5kg/km$^2$/month, 27.6∼81.7kg/km$^2$/month, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.3
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• pp.587-592
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• 2004

This research was aimed to manufacture the cholesterol free Mozzarella cheese with corn oil that contains high unsaturated fatty acid helping the reduction of serum cholesterol. Cheese stored at 1$0^{\circ}C$ was evaluated with general analysis, volatile free fatty acid, cholesterol, meltability, stretchability, color, rheological properties, and sensory evaluation. Moisture contents decreased during cheese storage period, whereas protein contents and pH value increased significantly (P < 0.05), but fat contents did not show any significant change. Linoleic acid was tile main volatile free fatty acid in a fat of cheese, and cholesterol contents were measured 4.34$\pm$ 0.04 mg/100 g in cheese. The meltability of cheese gradually increased during ripening, while the stretchability decreased. The color of cheese showed translucent yellow. Hardness, springiness, and cohesiveness increased significantly up to 21 days of storage. Compared to control cheese made by conventional way, QDA scores of shiny, oiling off, and melting of cholesterol free cheese were significantly different. These results suggested that health-oriented cholesterol free Mozzarella cheese would be made by addition of the corn oil.

• Korean Journal of Organic Agriculture
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• v.26 no.3
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• pp.489-500
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• 2018

Rural Development Administration (RDA) is promoting the AFACI IPM (Asian Food & Agricultural Cooperation Initiative program). AFACI consist of 12 countries including Bangladesh, Cambodia, Thailand, Vietnam and so on. The main goal of the AFACI IPM project is 'Establishment of an international cooperative network for the best management of migratory rice planthoppers and setting data-base of pests occurrence information. As a result of the suvey, Planthoppers were increasing all the way from tillering stage to ripe stage and do not appear to be peak of one or two like korea case. In detail, 1,673 of BPH (Nilaparvata lugens) occurred in survey site of Svay Reang, Cambodia, followed by 1.237 at Dobila, Bangladesh. In the case of White backed planthopper (Sogatella furcifera), 1,163 of WBPH occurred in survey site of Dobila, Bangladesh and 849 WBPH were collected at Hamkuria, Bangladesh. It is expected to verify the occurrence and movement patterns of hoppers among member countries in the future.

• Korean Journal of Materials Research
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• v.4 no.1
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• pp.117-124
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• 1994

The reduction of saturation magnetization in the Mg-Mn microwave ferrites was achieved by substituting the non-magnetic A1 ion for Fe ion. It is necessary for extending the operation frequencies that there is no change in other properties of the microwave ferrites. The electrical and magnetic properties are characterized where the composition of the ferrites studied was given by the general formula $(MgO)_{1.0}(MnO)_{0.1}(Al_xFe_{1.9-x}O_{2.85}$ with x ranging from 0.1 to 0.4. The saturation magnetization and the ferromagnetic resonance linewidth was decreased by the substituting amount of $Al_2O_3$. The value of coercive field was low enough over the composition of x=O.2 and the high squareness ratio was obtained all over the amount of substitution. It is feasible to select the proper application area with the combination of various properties ; that is, low coercive field, high squareness ratio, optimum saturation magnetization and ferromagnetic resonance linewidth.