• Title/Summary/Keyword: Materials science and engineering

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Parents Response for the Therapy Support Services Provided by Center for Special Education - Centered on Parents of Occupational Therapy Support Service - (특수교육지원센터 치료지원서비스에 대한 견해 - 작업치료 서비스를 받는 보호자를 중심으로 -)

  • Song, Min-Ok;Lee, Sung-Ja;Kim, Hun-Ju
    • The Journal of Korean Academy of Sensory Integration
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    • v.8 no.1
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    • pp.51-60
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    • 2010
  • Objective : The purpose of this study is to provide practical guidelines for the better performance of the Occupational therapy services(OT services) in the Supporting Center for Special Education. The study is based upon the quality and satisfaction of the OT services, measured by interviewing parents whose children have taken the services provided by Ulsan Kang-Nam Supporting Center for Special Education. Methods : Five parents for the children having OT services since March, 2010 in the Kang-Nam Supporting Center were interviewed individually. The interview per each person took thirty to fifty minutes and was all audio-recorded. Results : The satisfaction of the qualification for the OT therapists working at the Kang-Nam Supporting Center was high. The quality for treatment facilities and the variety for treatment materials met the expectation for OT to be well-performed. The free OT treatment system was the one of significant features for the OT services provided by the Kang-Nam Supporting Center. However, the perception of the interviewed parents for the OT was very low.

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Distribution Behavior of Ni between CaO-SiO2-Al2O3-MgO Slag and Cu-Ni Alloy (CaO-SiO2-Al2O3-MgO 슬래그와 Cu-Ni합금 사이의 Ni 분배거동)

  • Han, Bo-Ram;Sohn, Ho-Sang
    • Resources Recycling
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    • v.24 no.1
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    • pp.35-42
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    • 2015
  • To obtain the fundamental information on the dissolution of nickel into the slag in the pyrometallurgical processes for treatment of wasted PCB, the distribution ratios of nickel between CaO-$SiO_2-Al_2O_3$-MgO slag and copper-5 wt%Ni alloy were measured at 1623 K to 1823 K under a controlled $CO_2$-CO atmosphere. The distribution ratio of Ni increased linearly with increasing oxygen partial pressure. Therefore, the dissolution reaction of nickel into the slags could be described by the following equation; $$Ni(l)_{metal}+\frac{1}{2}O_2(g)NiO(l)_{slag}$$ The distribution ratio of Ni increased linearly with increasing content of basic oxides(CaO and MgO) in slag. However, the distribution ratio of Ni decreased linearly with increasing temperature. From these results, the empirical equation of distribution ratio of Ni was obtained by the following equation from the analysis of experimental conditions by multiple regression. $${\log}L_{Ni}=0.4000{\log}P_{O2}-5.1{\times}10^{-4}T+0.3375\(\frac{X_{CaO}+X_{MgO}}{X_{SiO2}}\)$$

Succession of Bacterial Populations in Cattle Manure Compost as Determined by Fluorescent In Situ Hybridization (우분 퇴비화에서의 Fluorescent In Situ Hybridization법에 의한 세균군집의 천이)

  • Lee, Young-Ok;Jo, Ik-Hwan;Kim, Kil-Woong
    • Journal of the Korea Organic Resources Recycling Association
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    • v.8 no.2
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    • pp.146-153
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    • 2000
  • To elucidate succession of bacterial populations, especially nitrifying bacteria during the composting of cattle manure with apple pomace, fluorescent in situ hybridization(FISH) using rRNA targeted oligonucleotide probes were applied. The density of ammonia-oxidizing bacteria was ranged from $3,3{\times}10^6cells/g$ dw to $13,4{\times}10^6cells/g$ dw with the peak value after 26 composting days whereas that of nitrite-oxidizing bacteria varied between $6.0{\times}10^6cells/g$ dw and $17.2{\times}10^6cells/g$ dw with the peak value after 7 composting days. And the tendency that the numbers of nitrite-oxidizing bacteria were higher than those of ammonia-oxidizing bacteria, and the peak-time of their densities were the same as that of data determined by the ratio of ammonia-oxidizing bacteria and nitrite-oxidizing bacteria to eubacteria. The peak of ammonia-oxidizing bacteria followed the peak of nitrite-oxidizing bacteria, at the late phase of composting process could be probably caused by the depletion of volatile ammonia of composting materials. Besides these results indicate that FISH method is a useful tool for detection of slow growing nitrifying bacteria.

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Analysis of Endcap Effect for MRI Birdcage RF Coil by FDTD Method (FDTD 방법을 이용한 MRI Birdcage RF Coil의 Endcap 효과 분석)

  • Chung Sung-Taek;Park Bu-Sik;Shin Yoon-Mi;Kwak June-Sik;Cho Jong-Woon;Kim Kyoung-Nam
    • Investigative Magnetic Resonance Imaging
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    • v.7 no.2
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    • pp.137-143
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    • 2003
  • Purpose : B1 field of birdcage RF (radiofrequency) coil that is used most for brain imaging in magnetic resonance imaging (MRI) decreases toward endring from the coil center. We investigated how much RE B1 homogeneity effect the endcap shield brings form the coil center as it towards to endcap region. Materials and Methods : We compared RF B1 field distribution by each finite difference time domain (EDTD) simulations for lowpass, highpass and hybrid birdcage RF coils. We selected the highpass birdcage RF coil that was the highest RF B1 field condition as simulation result, and studied how much RF B1 homogeneity effect was occurred when endcap shield was applied to endring area. Results : B1 field of the highpass birdcage RF coil was higher than other birdcage RF coil types as simulation result. However, the RF B1 homogeneity was lower than other coil types. RE B1 field of highpass birdcage RF coil with endcap shield is similar with RF B1 field of hybrid birdcage RF coil and the overall RE B1 homogeneity in sagittal direction was better. Conclusion In this paper, proposed method can apply improving RF B1 homogeneity of RF coil in clinical examination.

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Study on Formation Mechanism of Iron Oxide Nanoparticles (산화철 나노입자의 형성 메커니즘에 대한 연구)

  • Kim, Dong-Young;Yoon, Seok-Soo;Takahashi, Migaku
    • Journal of the Korean Magnetics Society
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    • v.22 no.5
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    • pp.167-172
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    • 2012
  • In order to analyze the formation mechanism of iron oxide nanoparticles, we measured the heat flow of $Fe(OL)_3$ precursor with temperature, and TEM images and AC susceptibility of aliquots samples sequentially taken from the reaction solution, respectively. The thermal decomposition of two OL-chain from $Fe(OL)_3$ produced the Fe-OL monomer, which were contributed to the formation of iron oxide nanoparticles. In the initial stage of nanoparticles formation, the small iron oxide nanoparticles had ${\gamma}-Fe_2O_3$ structure. However, as the iron oxide nanoparticles were rapidly growth, the iron oxide nanoparticles showed ${\gamma}-Fe_2O_3$-FeO core-shell structure which the FeO layer was formed on the surface of ${\gamma}-Fe_2O_3$ nanoparticles by insufficient oxygen supply from the reaction solution. These nanoparticles were transformed to $Fe_3O_4$ structure by oxidation during long aging time at high temperature. Finally, the $Fe_3O_4$ nanoparticles with high saturation magnetization and stable in the air could be easily synthesized by the thermal decomposition method.

Effect of Working Pressure on the Electrical and Optical Properties of ITZO Thin Films Deposited on PES Substrate with SiO2 Buffer Layer (공정압력이 SiO2 버퍼층을 갖는 PES 기판위에 증착한 ITZO 박막의 전기적 및 광학적 특성에 미치는 영향)

  • Joung, Yang-Hee;Choi, Byeong-Kyun;Kang, Seong-Jun
    • The Journal of the Korea institute of electronic communication sciences
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    • v.14 no.5
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    • pp.887-892
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    • 2019
  • In this study, after 20nm-thick $SiO_2$ thin film was deposited by PECVD method on the PES substrate, which is known to have the highest heat resistance among plastic substrates, as a buffer layer, ITZO thin films were deposited by RF magnetron sputtering method to investigate the electrical and optical properties according to the working pressure. The ITZO thin film deposited at the working pressure of 3mTorr showed the best electrical properties with a resistivity of $8.02{\times}10^{-4}{\Omega}-cm$ and a sheet resistance of $50.13{\Omega}/sq.$. The average transmittance in the visible region (400-800nm) of all ITZO films was over 80% regardless of working pressure. The Figure of merit showed the largest value of $23.90{\times}10^{-4}{\Omega}^{-1}$ in the ITZO thin film deposited at 3mTorr. This study found that ITZO thin films are very promising materials to replace ITO thin films in next-generation flexible display devices.

Photomixotrophic Growth of Solanum tuberosum L. in vitro with Addition and Omission of Organic Materials at Thee Initial Sucrose Levels in the Medium (세 수준의 자당이 첨가된 배지에서 유기물의 첨가 유무에 따른 Solanum tuberosum L.의 기내 광혼합영양생장)

  • Jeong, Byoung-Ryong;Yang, Chan-Suk;Kim, Gyeong-Hee;Park, Young-Hoon;Kozai, Toyoki
    • Journal of Bio-Environment Control
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    • v.13 no.1
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    • pp.51-55
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    • 2004
  • The most commonly used inorganic nutrient compositions such as Murashige & Skoog medium have been optimized for heterotrophic growth. Therefore, they may not be optimal for photomixotrophic and photoautotrophic growth of plantlets. In photomixotrophic micropropagation, emdium sugar level is often lowered, while light and $CO_2$ levels in vessel are raised, and chlorophyllous explants are used to facilitate photosynthetic carbon acquisition. In a factorial experiment effect of addition (+) and omission(_) of organic materials (OM, 0.5 g ${\cdot}$ $m^{-3}$ each of thiamine, nicotinic acid and pyridoxine and 100 ${\cdot}$ $m^{-3}$ myo-inositiol) combined with three sucrose levels (0, 15, and 30 kg ${\cdot}$ $m^{-3}$) was tested on the growth of potato plantlets. Each of nodal cuttings with a leaf was cultured on 0.1${\times}$$10^{-4}m^{-3}$) MS agar ( 8 kg ${\cdot}$ $m^{-3}$) medium (pH 5.80 before autoclave) in glass test tubes (100 mm${\times}$25mm) capped with a sheet of transparent film with a 6 mm diameter gas permeable filter (5.1 air exchanges ${\cdot}$$h^{-1}$). Cultures were maintained in a room for 27 days at $23^{\circ}C$, 50% RH, 350-450${\mu}mol\;{\codt}\;mol^{-1}CO_2$, 16 h ${\cdot}$ $d^{-1}$ photoperiod at 13${\mu}mol\;{\codt}\;m\;{\codt}\;s^{-1}$ PPFD provided by white cool fluorescent lamps. Growth of potato plantlet in the +OM and -OM treatments were similar, while medium pH was 0.2 scale lower in the latter. Dry weight, % dry matter, and stem diameter enhanced, while shoot to root dry weight ratio, leaf area, chlorophyll concentration per gram dry weight, and medium pH decreased with increasing initial sucrose level. Interaction between OM and sucrose levels was observed in shoot length and medium pH. Results indicate that OM can be omitted from the medium without detrimental effect while addition of sucrose was beneficial for the photomixotrophic growth of potato plantlets under raised light and $CO_2$.

Effect of Steam-Treated Zeolite BEA Catalyst in NH3-SCR Reaction (NH3-SCR 반응에서 스팀 처리된 zeolite BEA 촉매의 영향)

  • Park, Ji Hye;Cho, Gwang Hee;Hwang, Ra Hyun;Baek, Jeong Hun;Yi, Kwang Bok
    • Clean Technology
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    • v.26 no.2
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    • pp.145-150
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    • 2020
  • Nitrous oxide (N2O) is one of the six greenhouse gases, and it is essential to reduce N2O by showing a global warming potential (GWP) equivalent to 310 times that of carbon dioxide (CO2). Selective catalytic reduction (SCR) is a technology that converts ammonia into harmless N2 and H2O by using ammonia as a reducing agent to remove NOx, one of the air pollutants; the process also produces high denitrification efficiency. In this study, the Fe-BEA catalyst was steam-treated at 100 ℃ for 2 h before Fe ion exchange in the fixed bed reactor in order to investigate the effect of the steam-treated Fe-BEA catalyst on the NH3-SCR reaction. NH3-SCR reaction test of synthesized catalysts was performed at WHSV = 180 h-1, 370 to 400 ℃ in the fixed bed reactor. The Fe-BEA(100) catalyst steam-treated at 100 ℃ showed a somewhat higher activity than the Fe-BEA catalyst at 370 to 390 ℃. The catalysts were characterized by BET, ICP, NH3-TPD, H2-TPR, and 27Al MAS NMR in order to determine the cause affecting NH3-SCR activity. The H2-TPR result confirmed that the Fe-BEA(100) catalyst had a higher reduction of isolated Fe3+ than the Fe-BEA catalyst, and that the steam treatment increased the amount of isolated Fe3+ as an active species, thus increasing the activity.

Stress distribution of molars restored with minimal invasive and conventional technique: a 3-D finite element analysis (최소 침습적 충진 및 통상적 인레이 법으로 수복한 대구치의 응력 분포: 3-D 유한 요소 해석)

  • Yang, Sunmi;Kim, Seon-mi;Choi, Namki;Kim, Jae-hwan;Yang, Sung-Pyo;Yang, Hongso
    • Journal of Dental Rehabilitation and Applied Science
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    • v.34 no.4
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    • pp.297-305
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    • 2018
  • Purpose: This study aimed to analyze stress distribution and maximum von Mises stress generated in intracoronal restorations and in tooth structures of mandibular molars with various types of cavity designs and materials. Materials and Methods: Three-dimensional solid models of mandible molar such as O inlay cavity with composite and gold (OR-C, OG-C), MO inlay cavity with composite and gold (MR-C, MG-C), and minimal invasive cavity on occlusal and proximal surfaces (OR-M, MR-M) were designed. To simulate masticatory force, static axial load with total force of 200 N was applied on the tooth at 10 occlusal contact points. A finite element analysis was performed to predict stress distribution generated by occlusal loading. Results: Restorations with minimal cavity design generated significantly lower values of von Mises stress (OR-M model: 26.8 MPa; MR-M model: 72.7 MPa) compared to those with conventional cavity design (341.9 MPa to 397.2 MPa). In tooth structure, magnitudes of maximum von Mises stresses were similar among models with conventional design (372.8 - 412.9 MPa) and models with minimal cavity design (361.1 - 384.4 MPa). Conclusion: Minimal invasive models generated smaller maximum von Mises stresses within restorations. Within the enamel, similar maximum von Mises stresses were observed for models with minimal cavity design and those with conventional design.

Comparative proteome profiling in the storage root of sweet potato during curing-mediated wound healing (큐어링 후 저장에 따른 고구마 저장뿌리 단백질체의 비교분석)

  • Ho Yong Shin;Chang Yoon Ji;Ho Soo Kim;Jung-Sung Chung;Sung Hwan Choi;Sang-Soo Kwak;Yun-Hee Kim;Jeung Joo Lee
    • Journal of Plant Biotechnology
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    • v.50
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    • pp.1-10
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    • 2023
  • Sweet potato (Ipomoea batatas L. Lam) is an economically important root crop and a valuable source of nutrients, processed foods, animal feeds, and pigment materials. However, during post-harvest storage, storage roots of sweet potatoes are susceptible to decay caused by various microorganisms and diseases. Post-harvest curing is the most effective means of healing wounds and preventing spoilage by microorganisms during storage. In this study, we aimed to identify proteins involved in the molecular mechanisms related to curing and study proteomic changes during the post-curing storage period. For this purpose, changes in protein spots were analyzed through 2D-electrophoresis after treatment at 33℃ (curing) and 15℃ (control) for three days, followed by a storage period of eight weeks. As a result, we observed 31 differentially expressed protein spots between curing and control groups, among which 15 were identified. Among the identified proteins, the expression level of 'alpha-amylase (spot 1)' increased only after the curing treatment, whereas the expression levels of 'probable aldo-keto reductase 2-like (spot 3)' and 'hypothetical protein CHGG_01724 (spot 4)' increased in both the curing and control groups. However, the expression level of 'sporamin A (spot 10)' decreased in both the curing and control treatments. In the control treatment, the expression level of 'enolase (spot 14)' increased, but the expression levels of 'chain A of actinidin-E-64 complex+ (spot 19)', 'ascorbate peroxidase (spot 22)', and several 'sporamin proteins (spot 20, 21, 23, 24, 27, 29, 30, and 31)' decreased. These results are expected to help identify proteins related to the curing process in sweet potato storage roots, understand the mechanisms related to disease resistance during post-harvest storage, and derive candidate genes to develop new varieties with improved low-temperature storage capabilities in the future.