• Title, Summary, Keyword: Size Composition

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The Effect of Composition and Molecular Weight of Acrylic Copolymer on the Properties of Acrylic Size (아크릴 공중합체의 조성비와 분자량이 호제 특성에 미치는 영향)

  • 박찬준;김준호
    • Textile Science and Engineering
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    • v.36 no.9
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    • pp.680-686
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    • 1999
  • In order to investigate the controllability of $T_{g}$ in acrylic size within the industry-acceptable range, we synthesized acrylic copolymers of designed composition from ethyl acrylate (EA), methyl methacrylate (MMA) and acrylic acid (AA). Relationship between monomer feed ratio and composition ratio of EA/MMA in acrylic copolymers was confirmed by NMR analysis. The composition of MMA in acrylic copolymer was more abundant than in the monomer feed, and it was confirmed that MMA is much more reactive than EA from the evaluation of monomer reactivity ratios. Also, the reactivity ratio of each monomer was very similar in both polymerization method. The emulsion-polymerized size has a higher degree of polymerization than the solution-polymerized size, and the $T_{g}$ of size film increases with molecular weight at a fixed composition. The physical properties such as size pick-up, tenacity and cohesive property of the yarns sized with the acrylic size designed in this study are good, so it is suggested that the developed copolymer is suitable for practical use as warp size.

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Microstructural Characterization of Gas Atomized Copper-Iron Alloys with Composition and Powder Size

  • Abbas, Sardar Farhat;Kim, Taek-Soo
    • Journal of Korean Powder Metallurgy Institute
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    • v.25 no.1
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    • pp.19-24
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    • 2018
  • Cu-Fe alloys (CFAs) are much anticipated for use in electrical contacts, magnetic recorders, and sensors. The low cost of Fe has inspired the investigation of these alloys as possible replacements for high-cost Cu-Nb and Cu-Ag alloys. Here, alloys of Cu and Fe having compositions of $Cu_{100-x}Fe_x$ (x = 10, 30, and 50 wt.%) are prepared by gas atomization and characterized microstructurally and structurally based on composition and powder size with scanning electron microscopy (SEM) and X-ray diffraction (XRD). Grain sizes and Fe-rich particle sizes are measured and relationships among composition, powder size, and grain size are established. Same-sized powders of different compositions yield different microstructures, as do differently sized powders of equal composition. No atomic-level alloying is observed in the CFAs under the experimental conditions.

Reflectance Characteristics of Al-Si based Alloys according to Powder Size and Composition (Al-Si계 합금의 분말 크기 및 조성에 따른 반사율 변화 특성)

  • Choi, Gwang Mook;Chae, Hong Jun
    • Journal of Korean Powder Metallurgy Institute
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    • v.26 no.1
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    • pp.22-27
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    • 2019
  • In this study, the effects of powder size and composition on the reflectance of Al-Si based alloys are presented. First, the reflectance of Al-Si bulk and powder are analyzed to confirm the effect of powder size. Results show that the bulk has a higher reflectance than that of powder because the bulk has lower surface defects. In addition, the larger the particle size, the higher is the reflectance because the interparticle space decreases. Second, the effect of composition on the reflectance by the changing composition of Al-Si-Mg is confirmed. Consequently, the reflectance of the alloy decreases with the addition of Si and Mg because dendrite Si and $Mg_2Si$ are formed, and these have lower reflectance than pure Al. Finally, the reflectance of the alloy is due to the scattering of free electrons, which is closely related to electrical conductivity. Measurements of the electrical conductivity based on the composition of the Al-Si-Mg alloy confirm the same tendency as the reflectance.

Nanoemulsions containing Vitamin E acetate prepared by PIC(phase inversion composition) methods: Factors affecting droplet sizes

  • Kim, Eun-Hee;Cho, Wan-Goo
    • Journal of the Korean Applied Science and Technology
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    • v.30 no.4
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    • pp.602-611
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    • 2013
  • We have investigated the influence of system composition and preparation conditions on the particle size of vitamin E acetate (VE)-loaded nanoemulsions prepared by PIC(phase inversion composition) emulsification. This method relies on the formation of very fine oil droplets when water is added to oil/surfactant mixture. The oil-to-emulsion ratio content was kept constant (5 wt.%) while the surfactant-to-oil ratio (%SOR) was varied from 50 to 200 %. Oil phase composition (vitamin E to medium chain ester ratio, %VOR) had an effect on particle size, with the smallest droplets being formed below 60 % of VOR. Food-grade non-ionic surfactants (Tween 80 and Span 80) were used as an emulsifier. The effect of f on the droplet size distribution has been studied. In our system, the droplet volume fraction, given by the oil volume fraction plus the surfactant volume fraction, was varied from 0.1 to 0.3. The droplet diameter remains less than 350 nm when O/S is fixed at 1:1. The droplet size increases gradually as the increasing the volume fraction. Particle size could also be reduced by increasing the temperature when water was added to oil/surfactant mixture. By optimizing system composition and homogenization conditions we were able to form VE-loaded nanoemulsions with small mean droplet diameters (d < 50 nm). The PIC emulsification method therefore has great potential for forming nanoemulsion-based delivery systems for food, personal care, and pharmaceutical applications.

Diet composition and feeding strategy of John Dory, Zeus faber, in the coastal waters of Korea

  • Kim, Han Ju;Kim, Hyeong-Gi;Oh, Chul-Woong
    • Journal of Ecology and Environment
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    • v.44 no.1
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    • pp.54-61
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    • 2020
  • Background: Most fish undergo prey switch from juvenile to adult. It is thought that slightly different feeding habits occur among adult fishes due to growth, spawning, habitat change, and so on. Therefore, the diet of the John Dory Zeus faber (≥ 24 cm TL) was studied in the coastal waters of Korea by analysis of stomach contents, with comparison by season and size class of diet composition and prey diversity. Monthly samples were taken from February 2017 to January 2018. Results: The results showed that the John Dory was a piscivorous predator, and pisces had occupied 82.3% of IRI%. Trichiurus lepturus and Trachurus japonicus were important preys in all size classes and seasons. Diet composition differed among the size classes and seasons (Chi-square test, P < 0.05). As body size of Z. faber increased, the occurrence of benthic fish (Glyptocephalus stelleri) tended to increase. The seasonal prey composition also changed depending on the abundant species of each season. Conclusions: Z. faber is a piscivorous predator. The consumption habits of Z. faber appear to different results by their size and seasons. This study suggests that Z. faber could be considered an opportunistic predator.

A Study on the shrine plan composition from the Ungjindan excavation works (웅진단 발굴에 따른 사당의 평면구성에 관한 연구)

  • Kim, Sang-Tae
    • Korean Institute of Interior Design Journal
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    • v.21 no.6
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    • pp.186-193
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    • 2012
  • This study is to reveal the periodical form of the 4 staged building sites with the size and the site composition of the master plan and floor plan of the Ungjindan (altar) from the Ungjindan excavation works in 2011. In order to project the research results aiming to the purpose of the study, the basic study was done with collecting data about shrine architecture for its architectural characteristics and case studies with ancestral facilities such as the Ak hae dok (national-level ancestral ritual to the big mountain, ocean and river) to understand the exact form of the site plan and architectural composition elements through the general information and excavation status. In addition, with the current situation and information from the excavation works the planned measurement scale will be calculated in inference for the size of the construction by stages and speculate the floor plan composition of the shrine architecture.

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Catch per Unit Effort and Size Composition of Crayfish, Astacus leptodactylus Eschscholtz 1823, in Lake İznik

  • Balik, Ismet;Ozkok, Ergun;Ozkok, Remziye
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.6
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    • pp.884-889
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    • 2002
  • This paper was carried out from 15 June to 24 December in 2000 in Lake İznik of Turkey, to determine catch per unit effort (CPUE) and size composition of crayfish, Astacus leptodactylus Eschscholtz 1823, captured by fyke-nets of local fishermen. The average CPUE of all size groups was found as 1.65 crayfish/fyke-net/night for fishing season in 2000, but 26.4% of which was below the legal minimum size (crayfish<90 mm). The average CPUE of legal-sized (crayfish$\geq$90 mm) crayfish was 1.10 crayfish/fykenet/night. The annual catch of crayfish was estimated as 2990 tonnes. The length and weight compositions of crayfish captured in the fyke-nets have varied between 60 and 130 mm, and 6 and 71 g, respectively. The mean length and weight were found as 95.5 mm and 28.8 g for all size groups and 100.1 mm and 33.0 g for legal-sized individuals.

Effect of Composition Size of Sintered Body and Electrode on Resonant Characteristics of $Pb(Mn_{1/3}Nb_{2/3})O_3 PbTiO_3-PbZrO_3$ Piezoelectric Ceramics (소결체 및 전극의 크기와 조성이 $Pb(Mn_{1/3}Nb_{2/3})O_3 PbTiO_3-PbZrO_3$계 압전세라믹스의 공진특성에 미치는 영향)

  • 류영대;조상희
    • Journal of the Korean Ceramic Society
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    • v.23 no.1
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    • pp.60-66
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    • 1986
  • The effect of composition size of sintered body and electrode on resonant characteristics of the system $Pb(Mn_{1/3}Nb_{2/3})O_3 PbTiO_3-PbZrO_3$ has been decribed. Composition ranged from X=40 to X=55 diameter of sintered body ranged from D=6.5 to D=12.5(mm) and diameter of electrode ranged from De=5.5 to De=11 (mm) In the composition of morphotropic phase boundary antiresonant frequency (fa) dcreased slowly whereas resonant frequency (fr) decreased rapidly on the ground of this Δf(fa-fr) and electromechanical coupling fractor Kp increased and Qm showed low value. On the contrary in toward the composition of tetragonal and rhombo-hedral fa increased slowly whereas fr increased rapidly on the ground of this Δf and Kp decreased and Qm increased abruptly. Substance of the above statements have no concern with size of sintered body and ele-ctrode. The other side as the size of electrode decreased Qm fr, fa and Δf increased. Cm and Co dominantly affect the resonant frequency and antiresonant frequency.

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The Board Size and Board Composition Impact on Financial Performance: An Evidence from the Pakistani and Chinese's Listed Banking Sector

  • MAJEED, Muhammad Kashif;JUN, Ji Cheng;ZIA-UR-REHMAN, Muhammad;MOHSIN, Muhammad;RAFIQ, Muhammad Zeeshan
    • The Journal of Asian Finance, Economics, and Business
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    • v.7 no.4
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    • pp.81-95
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    • 2020
  • The main objective of this research is to investigate the impact of board size and board composition on financial performance of banks. The sample of this study consists on two countries listed bank sector Pakistan and China. The annul data is used from 2009-2018 to find the objective of this study. The Panel regression model is used to check the relationship between dependent and independent variables. Return on Asset and Return on Equity is used as performance checker dependent variables. The results of this study confirm board size coefficient value positive for ROA and negative for ROE but shows insignificant behavior for Pakistani banking sector while in Chinese banking sector the coefficient value of board size positively for ROA and ROE at 10% level. The board composition coefficient shows the negatively significant with ROA but insignificantly related to ROE for Pakistani banking sector. However, in Chinese banking sector the coefficient value of board composition is insignificant for both ROA and ROE. This study is helpful for banks, management of banks, policy makers, researcher as well as Government.

Effects of Several Factors on the Characteristics of Fe-Al Alloy Preform Manufactured by Reactive Sintering Process (반응소결법에 의해 제조된 Fe-Al합금 예비성형체의 특성에 미치는 제인자의 영향)

  • Joo, Hyung-Gon;Park, Sung-Hyuk;Joo, Sung-Min;Choi, Dap-Chun
    • Journal of Korea Foundry Society
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    • v.17 no.1
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    • pp.58-66
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    • 1997
  • The main aim of the present study is to investigate the effects of several processing parameters on the characteristics of Fe-Al alloy preform manufactured by reactive sintering process. The processing parameters include preform composition of 25, 40, 50, 60 and 75at.%Al, compacting pressure of 10, 20 and $30kg/cm^2$, and mean Al particle size of 29, 66 and $187{\mu}m$. Mean Fe particle size was $39{\mu}m$. The density of preform processed under same compacting pressure was not affected by changing Al composition. The preform with Al compositions of 25, 40, 50 and 60at.% Al swelled after reactive sintering process, thus having lower density than the green compacts. The preform with Al compositions of 75at.%Al, however, shrinked after reactive sintering process, thus having higher density than the green compacts. Ignition temperature increased with increasing compacting pressure, and increased with increasing Al composition at the fixed compacting pressure. And adiabatic temperature decreased with increasing compacting pressure at the fixed Al composition, and increased with increasing Al composition at the fixed compacting pressure. The size of compound particles increased with increasing Al composition. Especially, The size of compound particles increased largely in the case of 75at.%Al. It was observed that 50at.%Al preform have three dimentional network structure having a homogeneous and fine decreasing Al particle size.

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