• 제목/요약/키워드: Regional Characterization

검색결과 117건 처리시간 0.026초

Synthesis and Characterization of Methyltriethoxysilyl-Mediated Mesoporous Silicalites

  • Rabbani, Mohammad Mahbub;Oh, Weon-Tae;Nam, Dae-Geun
    • Transactions on Electrical and Electronic Materials
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    • 제12권3호
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    • pp.119-122
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    • 2011
  • A series of mesoporous silicalites was synthesized using different compositions of tetraethylorthosilicate and methyltriethoxysilane (MTES) as the silica source. Cetyltrimethylammonium bromide was used as the organic template. Their detailed pore structures were investigated by transmission electron microscopy, X-ray diffraction, and N2 adsorption method. The thermal properties of these silicalites were studied by thermogravimetric analysis. The increased amount of MTES destroyed mesoporous channels and reduced pore sizes from 3.4 nm to 2.8 nm in calcined silicalites. The calcined silicalite transformed completely into an amorphous state at 30% MTES loading. Methyl pending groups of MTES hindered the structural ordering of ≡Si-O- frameworks, resulting in an amorphous structure. This was caused by the insufficient formation of supramolecular assembly with the organic template. No capillary condensation step was found in MS 7/3 silicalite. The other capillary condensation steps shifted toward the lower relative pressure with increasing MTES content, indicating the reduction of pore sizes.

포도나무 (Vitis vinifero L.) 지상부로부터 분리한 항진균성 활성물질의 특성규명 (Characterization of an Antifungal Substance Isolated from Aerial Parts of Vitis vinifero L.)

  • 임태헌;권순열;최용화
    • 농약과학회지
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    • 제11권2호
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    • pp.82-86
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    • 2007
  • 포도나무 잎의 메탄올 추출물을 n-hexane, ethylacetate, n-butanol $H_2O$으로 순차적으로 용매분획 하였다. Ethylacetate 분획으로부터 silica gel chromatography와 재결정하여 활성물질을 분리 정제하였다. 이 화합물의 화학구조를 EI-MS의 조각 데이터를 근거로 분석한 결과 betulin으로 구조결정 되었다. 이 화합물이 고추 역병균(Phytophthora capsici), 고추 탄저병균(Colletotrichum acutatum)에 대한 항균활성(in vitro)을 측정한 결과, 100 ${\mu}g\;mL^{-1}$에서 각각 52.1%, 40.8%의 균사생육 억제효과를 보였으나, 잔디 마름병(Rhizoctonia solani) 균의 균사생육 억제 효과는 나타나지 않았다.

일본 노인주거시설의 종류와 공급특성에 관한 연구 (A Study on the Types and Supply of Elderly Housing in Japan)

  • 권순정
    • 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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    • 제16권3호
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    • pp.49-56
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    • 2010
  • In Japan, a lot of elderly housing types have been developed in order to meet various needs of the older person and the change of social situations. Elderly housings can be divided into three categories elderly housings for healthy older persons, elderly care homes for the healthy and elderly care facilities for the unhealthy. Elderly housings include public and private rental housings. Sometimes they can be designated only for the elderly. Elderly care homes for the healthy elderly include full fee charging elderly housing, elderly homes, low fee charging elderly homes and care houses. Elderly care facilities for the unhealthy elderly consist of full fee charging elderly care homes, group homes for the dementia, elderly health facilities, nursing homes, elderly hospitals, and so on. However "elderly care facilities" have been proved not to be efficient for the delivery of elderly welfare services nor satisfactory to the frail older person. Therefore, based on the concept of the "Normalization", daily services have been provided for the elderly in order that they can live at their own home in the community for themselves. As a result, Japan aims not only to reduce elderly welfare expenses but also to increase elderly users' satisfaction. Emphasis on non-institutionalization and in-home services, regional characterization, harmony between Hard and Soft, user oriented services, substantiality, universal design and so on are sought for the sake of those goals.

황산법을 이용한 루틸형 TiO2 분말의 제조 및 특성 평가 (Synthesis and Characterization of Rutile TiO2 Powder by the Sulfuric Acid Method)

  • 최순옥;조지희;김원용;임성환
    • 대한금속재료학회지
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    • 제50권7호
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    • pp.523-530
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    • 2012
  • We investigated the experimental method that uses the homogeneous precipitation method to prepare mica flakes-coated rutile-type titania pearlescent pigment with urea as a precipitant. $TiO_2$ particles exhibit a high reflection of lights and optical properties with chemical stabilities, so they are appropriate for coating on luminescent pigments (mica). The coating principle of mi ca coated titania with various thicknesses was analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and tested by spectrophotometer. Mica with a particle size in the range of $40-60{\mu}m$ was suspended in water, and metal sulphates and urea were added to the mixture, which was heated to boiling. The change in pH was continuously followed. The metal oxide and crystal structure were affected by the conditions of $TiOSO_4$ concentration and reaction time with a sintering temperature the range of $800-1100^{\circ}C$.

Morphological and molecular analysis of indigenous Myanmar mango (Mangifera indica L.) landraces around Kyaukse district

  • Kyaing, May Sandar;Soe, April Nwet Yee;Myint, Moe Moe;Htway, Honey Thet Paing;Yi, Khin Pyone;Phyo, Seinn Sandar May;Hlaing, Nwe Nwe Soe
    • Journal of Plant Biotechnology
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    • 제46권2호
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    • pp.61-70
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    • 2019
  • There is vast genetic diversity of Myanmar Mangoes. This study mainly focused on indigenous thirteen different mango landraces cultivated in central area of Myanmar, Kyauk-se District and their fruit characteristics by 18 descriptors together with genetic relationship among them by 12 SSR markers. Based on the morpho-physical characters, a wide variation among accessions was found. Genetic characterization of thirteen mango genotypes resulted in the detection of 302 scorable polymorphic bands with an average of 4.33 alleles per locus and an average polymorphism information content (PIC) of 0.7. All the genotypes were grouped into two major clusters by UPGMA cluster analysis and a genetic similarity was observed in a range of 61 ~ 85%. This study may somehow contribute insights into the identification of regional mango diversity in Myanmar and would be useful for future mango breeding program.

Clear cell odontogenic carcinoma: a mini review

  • Kim, Young Hwan;Seo, Eun Jin;Park, Jae Kyung;Jang, Il Ho
    • International Journal of Oral Biology
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    • 제44권3호
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    • pp.77-80
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    • 2019
  • Clear cell odontogenic carcinoma (CCOC), a very rare neoplasm located mostly in the mandible, has been regarded as a benign tumor. However, due to the accumulation of case reports, CCOC has been reclassified as a malignant entity by the World Health Organization. Patients with CCOC present with regional swelling and periodontal indications with variable pain, often remaining misdiagnosed for a long period. CCOC has slow growth but aggressive behavior, requiring radical resection. Histologic analysis revealed the monophasic, biphasic, and ameloblastic types of CCOC with clear cells and a mixed combination of polygonal and palisading cells. At the molecular level, CCOC shows the expression of cytokeratin and epithelial membrane antigen, along with markers that assign CCOC to the sarcoma family. At the genetic level, Ewing sarcoma breakpoint region 1-activating transcription factor 1 fusion is regarded as the key feature for identification. Nevertheless, the scarcity of cases and dependence on histological data delay the development of an efficient therapy. Regarding the high recurrence rate and the potential of distant metastasis, further characterization of CCOC is necessary for an early and accurate diagnosis.

High resolution size characterization of particulate contaminants for radioactive metal waste treatment

  • Lee, Min-Ho;Yang, Wonseok;Chae, Nakkyu;Choi, Sungyeol
    • Nuclear Engineering and Technology
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    • 제53권7호
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    • pp.2277-2288
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    • 2021
  • To regulate the safety protocols in nuclear facilities, radioactive aerosols have been extensively researched to understand their health impacts. However, most measured particle-size distributions remain at low resolutions, with the particle sizes ranging from nanometer to micrometer. This study combines the high-resolution detection of 500 size classes, ranging from 6 nm to 10 ㎛, for aerodynamic diameter distributions, with a regional lung deposition calculation. We applied the new approach to characterize particle-size distributions of aerosols generated during the plasma arc cutting of simulated non-radioactive steel alloy wastes. The high-resolution measured data were used to calculate the deposition ratios of the aerosols in different lung regions. The deposition ratios in the alveolar sacs contained the dominant particle sizes ranging from 0.01 to 0.1 ㎛. We determined the distribution of various metals using different vapor pressures of the alloying components and analyzed the uncertainties of lung deposition calculations using the low-resolution aerodynamic diameter data simultaneously. In high-resolution data, the changes in aerosols that can penetrate the blood system were better captured, correcting their potential risks by a maximum of 42%. The combined calculations can aid the enhancement of high-resolution measuring equipment to effectively manage radiation safety in nuclear facilities.

자발적 환원반응에 의한 음이온 교환막 수전해용 Pt-Ni 나노 촉매 제조 및 특성 (Preparation and Characterization of Pt-Ni Nanocatalyst for Anion Exchange Membrane in Alkaline Electrolysis by Spontaneous Reduction Reaction)

  • 장붕비;이재영;이홍기
    • 한국수소및신에너지학회논문집
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    • 제33권3호
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    • pp.202-208
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    • 2022
  • Pt-Ni nanocatalysts were loaded on carbon black by spontaneous reduction reaction of platinum (II) acetylacetonate and nickel (II) acetylacetonate, and they were characterized by transmission electron microscopy (TEM), thermogravimetric analyzer (TGA), energy dispersive x-ray analyzer (EDS), BET surface area and fuel cell test station. The distribution of the Pt and Ni nanoparticles was observed by TEM, and the loading weight of Pt-Ni nanocatalysts on the carbon black was measured by TGA. The elemental ratio of Pt and Ni was estimated by EDS. It was found that the loading weight of Pt-Ni nanoparticles was 5.54 wt%, and the elemental ratio of Pt and Ni was 0.48:0.35. Specific surface area was measured by BET analysis instrument and I-V characteristics were estimated.

PVD CrN 코팅 금형의 TRIP1180 판재 성형 시 금형의 표면상태에 따른 제품 표면특성 평가 (Characterization of Product Surface according to Tool Surface Conditions when Forming TRIP1180 Steel Sheets with PVD CrN-coated Tools)

  • 방준호;배기현;김민기;이명규;김홍기;송정한
    • 소성∙가공
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    • 제32권5호
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    • pp.247-254
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    • 2023
  • This study conducted the wear tests on bending punches coated with PVD CrN and examined the surface quality of the product formed by each punch in the forming of uncoated TRIP1180 sheets. The study quantitatively estimated the surface quality of the product by measuring the roughness and imaging the product surface. The correlation between the punch wear depth and the product surface roughness was quantitatively analyzed. The results showed that before failure occurs, the product roughness was comparable with that of the as-received, and the product surface was smooth without scratches and defects. However, after failure, the punch wear is caused by fretting wear mechanism, and a punch whose coating is not completely peeled plows the product surface, resulting in severe scratches with grooves and ridges on the product surface. Severe wear on the punch surface caused by fretting wear can rapidly degrade the product surface quality as it is directly affected by the punch surface condition, and the product surface quality accurately reflects the punch wear condition.

음이온 교환막 수전해용 Pt-Fe/카본블랙 나노 촉매 제조 및 특성 (Preparation and Characterization of Pt-Fe/Carbon Black Nanocatalyst for Anion Exchange Membrane in Alkaline Electrolysis)

  • 조성국;이재영;이홍기
    • 한국수소및신에너지학회논문집
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    • 제33권6호
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    • pp.715-722
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    • 2022
  • Pt-Fe/carbon black nanocatalysts were prepared by spontaneous reduction reaction of Platinum(II) acetylacetonate and Iron(II) acetylacetonate in a nucleophilic solvent and they were characterized by scanning electron microscopy (SEM), energy dispersive X-ray analyzer (EDS), thermogravimetric analyzer (TGA), transmission electron microscopy (TEM), Brunauer, Emmett and Teller (BET) surface area analysis and anion exchange membrane (AEM) water electrolysis test station. The distribution of the Pt and Fe nanoparticles on carbon black was observed by TEM, and the loading weight of Pt-Fe nanocatalysts on the carbon black was measured by TGA. Elemental ratio of Fe:Pt was estimated by EDS and it was found that elemental ratio of Pt and Fe was changed in the range of 1:0 to 0:1, and the loading weight of Pt-Fe nanoparticles on the carbon black was 5.95-6.78 wt%. Specific surface area was greatly reduced because Pt-Fe nanocatalysts blocked the pores. I-V characteristics were estimated.