• Title/Summary/Keyword: Size Composition

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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 Powder Materials
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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 Powder Materials
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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.

Decomposing the Effect of Population Changes on Crime Changes

  • Lee, Soochang;Jang, Cheolyeung
    • International Journal of Advanced Culture Technology
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    • v.9 no.1
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    • pp.1-6
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    • 2021
  • This study aims to test the relationship between the change in population size and population composition and crime changes. The analytical model includes variables representing changes in population size and population composition, three dependent variables for crime changes, and three control variables. Changes in popuvpdllation size and population composition are measured by indicators such as population size, gender, age groups, and immigrants and foreign workers, and crime changes by felonious, burglary, and violent crime volumes. The sample includes 154 cities and counties in South Korea, and the sample period is from 2010 to 2017. As a result of the analysis, I examine that the decrease in the number of young and men are likely to lead to a decline in felonious and violent crimes, but a high rate of the elderly and the increasing racial heterogeneity are likely to accelerate the fear and worries about crimes.

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.

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.

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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Effects of High Dietary Calcium and Fat Levels on the Performance, Intestinal pH, Body Composition and Size and Weight of Organs in Growing Chickens

  • Shafey, T.M.
    • Asian-Australasian Journal of Animal Sciences
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    • v.12 no.1
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    • pp.49-55
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    • 1999
  • The effect of fat supplementation of high calcium (Ca) diets on the performance, intestinal pH, body composition and size and weight of organs in growing chickens were investigated in two experiments. Growing chickens tolerated a high dietary level of Ca (22.5 vs 12.1 g/kg) in the presence of 6.3 g/kg of available phosphorus without any significant effect on performance. Intestinal pH was significantly increased by the addition of excess Ca and fat which probably created the right pH for the formation of insoluble Ca soaps. Excess dietary Ca increased carcass linoleic acid concentration at the expense of palmitic and stearic acid contents, whilst the addition of sunflower oil (80 g/kg diet) to the diet increased carcass linoleic acid concentration at the expense of palmitic acid content of the carcass. Intestinal and visceral organ size and weight were not influenced by excess Ca or fat. However, there was a non significant increase in the intestinal dry weight per unit of length caused by excess dietary Ca. It was concluded that excess dietary Ca of 22.5 g/kg did not significantly influence the performance of meat chickens. However, excess Ca increased intestinal pH and altered carcass fatty acid composition. Fat supplementation did not alter intestinal pH with high Ca diets. Excess dietary fat altered carcass fatty acid composition and reduced protein content. Intestinal and visceral organ size and weights were not influenced by excess dietary levels of Ca of fat.

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.

An Analysis on the Characteristic of the Master-Zone Planning in the Apartment Building (공동주택의 부부 전용공간 분석)

  • Park, So-Yun;Lee, Kyung-A;Lee, Hyun-Soo
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2005.11a
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    • pp.189-192
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    • 2005
  • The purpose of this study is to analyze space composition and size of the Master Zone in the apartment unit plan. For this, we analyzed 435 samples by searching web-sites of the 5 main construction companies. The major results of this study are as follows. 1) Master Zone is organized 4 spaces such as main room, bathroom and make-up & dress room. Six types of Master Zone are classified with the composition of 4 spaces. 2) The size of the Master Zone is increased in proportion to the square meter. But the range of the ratio is small range of fluctuation as 20%${\sim}$30%. 3)The size and ratio of the each spaces of the Master Zone are analyzed. The size of bedroom is increased but the ratio is decreased. The size of bathroom is increased but the ratio is regular as 4%${\sim}$5%. The size of make-up and dressing room is generally increased but the range of the size and ratio is the most extensive. Through this analysis and research, this study would be provied the basic data for actual housing planning and to contribute to future trends of apartment houses.

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