• Title/Summary/Keyword: Micro-content

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Compositional and microstructural analyses of grayish-blue-powdered celadon in Yeongseo Region in Gangwon-do:by Wonju Beopcheon-temple site (강원도 영서지역 출토 분청사기의 조성 및 미세구조 분석: 원주(原州) 법천사지(法泉寺址)를 중심으로)

  • Lee, Byoung-Hoon;So, Myoung-Gi
    • Analytical Science and Technology
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    • v.26 no.3
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    • pp.211-221
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    • 2013
  • This research aims to examine compositional and microstructural properties of grayish-blue-powdered celadon in Wonju Beopcheon-temple site. X-ray fluorescence sequential spectroscopy (XRF) with micro-point analysis, scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) were applied to determine the chemical composition, microstructure and crystallinity of samples, respectively. As a result, the average compositions of bodies were low silica ($RO_2$) and high flux (RO+$R_2O$). Owing to the high content of calcium oxide the glaze is considered lime type between limealkali type. The body of celdon sheard was found quarts, mullite, microcline, albite. Especially, the body's chemical compositions were compared to the results of previous studies by using a Seger formula. The compositional properties of Grayish-blue-powdered celadon in Wonju Beopcheon-temple site showed diffrently from the the other grayish-blue-powdered celadon.

A Study on the Strength Properties of Green Mortar Using Limestone Powder (석회석(石灰石) 미분말(微粉末)을 이용(利用)한 그린모르타르의 강도(强度) 특성(特性)에 관한 연구(硏究))

  • Jo, Byung-Wan;Choi, Ji-Sun;Kim, Kyung-Tae
    • Resources Recycling
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    • v.22 no.3
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    • pp.36-42
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    • 2013
  • According to the recent community-based structures enlargement, specification, and diversification. It needs appropriate construction materials in terms of intensity and environmental aspects. Thus, in manufacturing the cement using micro limestone powder which is main material. It is also expected to save energies and reduces $CO_2$, by using the blast furnace slag and fly ash which are mitigated environmental load construction materials that emerged. In this research, The durability aspect tries to be grasped considering the chemical property according to the coherence of the hydration product. Consequently, The compressive strength was measured over 30 Mpa on 3rd. In addition, according to the content of the limestone powder, the setting time is promoted. It has the feature expanded in the length change. And it is determined because the possibility of replacing the existing for construction material such as it is measured compared with the time to use the portland cement usually that flexural strength is high with the age 7 days ago, so it is sufficient.

Analysis of Mean Deviation in Sliding-wear-rate of Carbon Steel with Various Pearlite Volume Fractions (탄소강의 펄라이트 분율에 따른 미끄럼 마멸속도 편차 분석)

  • Kim, M.G.;Gwon, H.;Hur, H.L.;Kim, Y.-S.
    • Transactions of Materials Processing
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    • v.24 no.3
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    • pp.205-211
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    • 2015
  • The current investigation was performed to study sliding-wear-rate deviation (wear-rate data scatter) in carbon steels with various microstructures. Pure iron, 0.2 wt. % C steel, 0.45 wt. % C steel, and bearing steel (AISI52100) were used for the investigation. These steels possess different microstructures. Microstructures of the pure iron, two carbon steel and the bearing steel were full ferrite, ferrite + pearlite and full pearlite, respectively. Depending on the carbon content, the carbon steel had different pearlite-volume fractions. Dry sliding wear tests of the steel were conducted using a ball-on-disk wear tester at a sliding speed of 0.1 m/s using a bearing ball (AISI52100) as a counterpart. Applied load and sliding distance were 100 N and 300 m, respectively. More than three (up to twelve) tests were conducted for each steel under the same conditions, and the mean deviations in the wear rate of the steel (microstructure) were compared. The wear-rate deviation in the steel with ferrite + pearlite microstructure was higher than that with ferrite microstructure, and the deviation decreased with the increase of pearlite volume fraction. The pure iron and the bearing steel specimens showed much less deviation. The high deviation observed from the ferrite + pearlite steel was attributed to irregular subsurface-crack nucleation and growth at the interface between the two micro constituents (ferrite and pearlite) during the wear test.

Application of Exergy in Aquatic Ecosystems Health Assessment : Experimental Approach and Field Observations (수계 생태계의 건강성 평가 척도로서의 엑서지 적용성에 관한 연구: 실험 및 야외 관찰)

  • Silow, Eugene A.;Oh, In-Hye
    • Korean Journal of Ecology and Environment
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    • v.36 no.2 s.103
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    • pp.117-123
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    • 2003
  • The results of field experiments with mesocosms on Lake Baikal, containing natural plankton assemblage, and laboratory experiments with microcosms containing Daphnia magna and Chlorella vulgaris demonstrated decrease of the structural exergy of the communities after the addition of allochtonous compounds peptone, diesel oil, o-diphenol, $CdCl_2$ to mesocosmsassemblage, phenol, $CoCl_2$ and $CuSO_4$ to micro-cosms. Structural exergy changes were more expressed than changes of components biomasses and total biomass of the community. Comparison of exergy content for benthos in cleanand affected by the discharges of Baikalsk Pulp and Paper Combine also showed sufficient docrease of structural exergy in polluted area. It points to the possibility of the use of structural exergy as ecosystem health reflecting parameter.

Low-Molecular-Weight Collagen Peptide Ameliorates Osteoarthritis Progression through Promoting Extracellular Matrix Synthesis by Chondrocytes in a Rabbit Anterior Cruciate Ligament Transection Model

  • Lee, Mun-Hoe;Kim, Hyeong-Min;Chung, Hee-Chul;Kim, Do-Un;Lee, Jin-Hee
    • Journal of Microbiology and Biotechnology
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    • v.31 no.10
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    • pp.1401-1408
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    • 2021
  • This study examined whether the oral administration of low-molecular-weight collagen peptide (LMCP) containing 3% Gly-Pro-Hyp with >15% tripeptide (Gly-X-Y) content could ameliorate osteoarthritis (OA) progression using a rabbit anterior cruciate ligament transection (ACLT) model of induced OA and chondrocytes isolated from a patient with OA. Oral LMCP administration (100 or 200 mg/kg/day) for 12 weeks ameliorated cartilage damage and reduced the loss of proteoglycan compared to the findings in the ACLT control group, resulting in dose-dependent (p < 0.05) improvements of the OARSI score in hematoxylin & eosin (H&E) and Safranin O staining. In micro-computed tomography analysis, LMCP also significantly (p < 0.05) suppressed the deterioration of the microstructure in tibial subchondral bone during OA progression. The elevation of IL-1β and IL-6 concentrations in synovial fluid following OA induction was dose-dependently (p < 0.05) reduced by LMCP treatment. Furthermore, immunohistochemistry illustrated that LMCP significantly (p < 0.05) upregulated type II collagen and downregulated matrix metalloproteinase-13 in cartilage tissue. Consistent with the in vivo results, LMCP significantly (p < 0.05) increased the mRNA expression of COL2A1 and ACAN in chondrocytes isolated from a patient with OA regardless of the conditions for IL-1β induction. These findings suggest that LMCP has potential as a therapeutic treatment for OA that stimulates cartilage regeneration.

European Integration Processes for the Development of Future Foreign Language Specialists in the Information Society

  • Lazarenko, Natalia;Zadorozhna, Olga;Prybora, Tetiana;Shevchuk, Аndrii;Sulym, Volodymyr;Rudnytska, Nataliya
    • International Journal of Computer Science & Network Security
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    • v.21 no.12spc
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    • pp.427-436
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    • 2021
  • The article reveals and theoretically substantiates the trends of foreign language teachers' professional training in universities of Ukraine in terms of European integration, which are systematized in three areas: macro-level (system of education), meso-level (universities) and micro-level (subjects of educational process). The article aims to substantiate the trends of foreign language teacher training in the context of European integration and the main directions of creative use of constructive ideas of European experience in the innovative development of education. The article lights up the system for improving foreign language teacher training in universities, which is based on updated goals, content and approaches to the implementation of basic concepts, principles and features of teacher training in European experience, enable us to improve the quality of teacher training, its competitiveness in the European labor market. In the article developed the conceptual model of strategic development of the university in the conditions of European integration. It is emphasized that information technologies provide great opportunities for the development of professional skills and intellectual potential of future professionals. At present, the computerization of the educational process in higher education institutions is considered as one of the first and most promising areas for improving the quality of education. The article offered directions of internationalization of educational activity of university in the conditions of European integration. Diagnostic tools for the development of the university in terms of integration into the European educational space, individual rating and ranking of structural units of the university have been developed; main directions of activity of the laboratory of the skill of the teacher of higher school and methodical recommendations on the creation and the organization of work of scientific laboratories.

Crosstalk of Zn in Combination with Other Fertilizers Underpins Interactive Effects and Induces Resistance in Tomato Plant against Early Blight Disease

  • Awan, Zoia Arshad;Shoaib, Amna;Khan, Kashif Ali
    • The Plant Pathology Journal
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    • v.35 no.4
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    • pp.330-340
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    • 2019
  • The present study was undertaken to evaluate the integrated effect of zinc (Zn) with other nutrients in managing early blight (EB) disease in tomato. A pot experiment was carried out with basal application of the recommended level of macronutrients [nitrogen, phosphorus and potassium (NPK)] and micronutrients [magnesium (Mg) and boron (B)] in bilateral combination with Zn (2.5 and 5.0 mg/kg) in a completely randomized deigned in replicates. Results revealed that interactive effect of Zn with Mg or B was often futile and in some cases synergistic. Zn with NPK yield synergistic outcome, therefore EB disease was managed significantly (disease incidence: 25% and percent severity index: 13%), which resulted in an efficient signaling network that reciprocally controls nutrient acquisition and uses with improved growth and development in a tomato plant. Thus, crosstalk and convergence of mechanisms in metabolic pathways resulted in induction of resistance in tomato plant against a pathogen which significantly improved photosynthetic pigment, total phenolics, total protein content and defense-related enzymes [superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), polyphenol oxidase (PPO) and phenylalanine ammonia-lyase (PAL)]. The tremendous increase in total phenolics and PAL activity suggesting their additive effect on salicylic acid which may help the plant to systemically induce resistance against pathogen attack. It was concluded that interactive effect of Zn (5.0 mg/kg) with NPK significantly managed EB disease and showed positive effect on growth, physiological and biochemical attributes therefor use of Zn + NPK is simple and credible efforts to combat Alternaria stress in tomato plants.

A Study on the NOx Reduction According to the Space Velocity Variation and Binder Content of Metal foam SCR Catalyst for Cogeneration Power Plant Application (열병합발전소 적용을 위한 Metal foam SCR촉매의 공간속도와 바인더 함량에 따른 NOx 저감에 관한 연구)

  • Na, Woo-Jin;Park, Hea-Kyung
    • Journal of the Korean Applied Science and Technology
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    • v.36 no.1
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    • pp.153-164
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    • 2019
  • To develop a high performance SCR catalyst which has better specific surface area, lightness of weight and fast temperature response than those of existing commercial SCR catalyst, metal foam type SCR catalysts were prepared by washcoating with vanadium, tungsten and binder. The de-NOx performance test of the prepared catalysts was carried out on atmospheric micro-test unit at lab. scale according to space velocity variation and temperature change, and the characteristics of them were analyzed by Porosimeter, SEM(scanning electron microscope), EDX(energy dispersive x-ray spectrometer), ICP(inductively coupled plasma) and Stereomicroscope. The NOx reduction performance decreased as the space velocity increased and was found to be the best at 3.5 wt.% contents of the vanadium and tungsten. It was found that the larger amount of binder was added, the worse the NOx reduction performance was, which was considered to be that the number of active sites of the prepared catalyst surface was occupied by the binder. We found that the amount of binder to be added to prepare the catalyst should be properly controlled by the condition of coated catalyt surface.

Monochromatic Amber Light Emitting Diode with YAG and CaAlSiN3 Phosphor in Glass for Automotive Applications

  • Lee, Jeong Woo;Cha, Jae Min;Kim, Jinmo;Lee, Hee Chul;Yoon, Chang-Bun
    • Journal of the Korean Ceramic Society
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    • v.56 no.1
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    • pp.71-76
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    • 2019
  • Monochromatic amber phosphor in glasses (PiGs) for automotive LED applications were fabricated with $YAG:Ce^{3+}$, $CaAlSiN_3:Eu^{2+}$ phosphors and Pb-free silicate glass. After synthesis and thickness-thinning process, PiGs were mounted on high-power blue LED to make monochromatic amber LEDs. PiGs were simple mixtures of 566 nm yellow YAG, 615 nm red $CaAlSiN_3:Eu^{2+}$ phosphor and transparent glass frit. The powders were uniaxially pressed and treated again through CIP (cold isostatic pressing) at 200 MPa for 20 min to increase packing density. After conventional thermal treatment at $550^{\circ}C$ for 30 min, PiGs were applied by using GPS (gas pressure sintering) to obtain a fully dense PiG plate. As the phosphor content increased, the density of the sintered body decreased and PiGs containing 30 wt% phosphor had full sintered density. Changes in photoluminescence spectra and color coordination were investigated by varying the ratio of $YAG/CaAlSiN_3$ and the thickness of the plates. Considering the optical spectrum and color coordinates, PiG plates with $240{\mu}m$ thickness showed a color purity of 98% and a wavelength of about 605 nm. Plates exhibit suitable optical characteristics as amber light-converting material for automotive LED applications.

Particle Dissolution Effects on Soluble Geo-Mixtures (용해성 지반혼합재의 입자 용해 영향)

  • Tran, M. Khoa;Cho, Se-Hyun;Byun, Yong-Hoon;Shin, Ho-Sung;Lee, Jong-Sub
    • Journal of the Korean GEO-environmental Society
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    • v.12 no.12
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    • pp.5-12
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    • 2011
  • Macro- and micro-behaviors of soluble granular media during dissolution process is investigated by numerical analysis. Soluble media are represented by assemblies of non-soluble particles and soluble particles with the different soluble particles contents. Dissolutions of particles are implemented by reducing sizes of soluble particles. The numerical simulations results exhibit that the vertical displacements increase to certain times and become constant while the porosities still increase until no soluble particles are present. However, the porosities and vertical displacements increase with the increase of soluble particles content. The microscopic views show that the fabrics of media change during dissolution process until the certain times, the higher soluble particles contents, and the larger change in fabric.