• Title/Summary/Keyword: density character

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Strategic design for oxide-based anode materials and the dependence of their electrochemical properties on morphology and architecture

  • Gang, Yong-Muk
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2012.05a
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    • pp.73-73
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    • 2012
  • Modern technology-driven society largely relies on hybrid electric vehicles or electric vehicles for eco-friendly transportation and the use of high technology devices. Lithium rechargeable batteries are the most promising power sources because of its high energy density but still have a challenge. Graphite is the most widely used anode material in the field of lithium rechargeable batteries due to its many advantages such as good cyclic performances, and high charge/discharge efficiency in the initial cycle. However, it has an important safety issue associated with the dendritic lithium growth on the anode surface at high charging current because the conventional graphite approaches almost 0 V vs $Li/Li^+$ at the end of lithium insertion. Therefore, a fundamental solution is to use an electrochemical redox couple with higher equilibrium potentials, which suppresses lithium metal formation on the anode surface. Among the candidates, $Li_4Ti_5O_{12}$ is a very interesting intercalation compound with safe operation, high rate capability, no volume change, and excellent cycleability. But the insulating character of $Li_4Ti_5O_{12}$ has raised concerns about its electrochemical performance. The initial insulating character associated with Ti4+ in $Li_4Ti_5O_{12}$ limits the electronic transfer between particles and to the external circuit, thereby worsening its high rate performance. In order to overcome these weak points, several alternative synthetic methods are highly required. Hence, in this presentation, novel ways using a synergetic strategy based on 1D architecture and surface coating will be introduced to enhance the kinetic property of Ti-based electrode. In addition, first-principle calculation will prove its significance to design Ti-based electrode for the most optimized electrochemical performance.

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Surface Electronic Structures and Magnetism of a Full-Heusler Alloy Co2CrGa(001): A First-principles Study

  • Jin, Ying-Jiu;Lee, Jae-Il
    • Journal of Magnetics
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    • v.12 no.3
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    • pp.97-102
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    • 2007
  • We have investigated the electronic structures and magnetism of a full Heusler alloy $Co_2CrGa(001)$ surface by using the all-electron full-potential linearized augmented plane wave (FLAPW) method within the generalized gradient approximation (GGA). We considered two types of different terminations: the Co-terminated (Co-Term) and the CrGa-terminated (CrGa-Term) surfaces. From the calculated layer-projected density of states (LDOS), we found that the surface of the CrGa-Term shows nearly half-metallic character while that of the Co-Term is far from the half-metallic. For the Co-Term, the surface Co atom moves down to the bulk region by $0.05{\AA}A$, while the subsurface Cr and Ga atoms move up to the surface layer by 0.05 and $0.01{\AA}$, respectively. For the CrGa-Term, there is a large inward relaxation of the surface Ga atom $(0.07{\AA})$, but the relaxation of the surface Cr atom is very small $(0.01{\AA})$. The relaxations affect not much to the overall shapes of DOS for both terminations, but make the surface states of the surface Cr and Ga atoms for the CrGa-Term shift to higher energy that enhances the nearly half-metallic character of the CrGa-Term. The magnetic moments of the surface $Cr(2.98{\mu}_B)$ in the CrGa-Term and the surface $Co(1.17{\mu}_B)$ in the Co-Term were much increased compared to those of the inner-layers $(1.79\;and\;0.77{\mu}_B)$, respectively, while that of the subsurface Cr atom in the Co-Term was decreased to $1.19{\mu}_B$.

Population Fluctuation, Developmental Character of Panonychus citri and Damage Degree as its Control Density on Young Yuzu (Citrus junos) (유자에서 귤응애의 발생소장, 온도별 발육특성 및 방제밀도별 피해정도)

  • 최덕수;김규진
    • Korean journal of applied entomology
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    • v.37 no.2
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    • pp.193-198
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    • 1998
  • Experiments were conducted to investigate the population fluctuation, developmental periods, fecundity, hatching rate and demage of Citrus red mite (Panonychus citri M.) on Yuzu trees (citrus junos T.) from 1996 to 1997. Citrus red mite occurred from May to November and made two peaks. The first peak was in July to August and the secondary peak was in October. Density of the second peak was higher (9.5 miteslleaf) than that of the first peak. In the constitution rate of each developmental stage of citrus red mite on Yuzu leaves, egg stage occupied 85%. At the four constant temperature (15, 20, 25, 30 + 1$^{\circ}$C, RH 60 + lo%, 14L- IOD) conditions, the developmental period from egg to adult was 41 .l, 15.5, 11.0 and 9.4 days ; Mean longevity of adult was 23.3, 8.3, 6.3, and 6.1 days; Mean number of egg laid per female per day was 1.6, 3.2, 4.5, 4.0 eggs; Mean hatching rate was 66.6, 85.7, 90.7 and 94.7% at above temperature, respectively. When sprayed acaricide at different density of Citrus red mite, the growth of young Yuzu tree were better at low density. Defoliation rate during winter was 13.5, 20.6, 53.1, 72.6% at 4 control density 1 , 3, 6 mites per leaf and uncontrolled (10 ( ). When every time spray acaricide under 3 mites per leaf, defoliation rate during winter suppressed above 50% compare to uncontrol 72.6%.

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Theoretical Studies on the Structure and Aromaticity of 1H-Indene and Mono-sila-1H-Indene (1H-Indene과 Mono-sila-1H-Indene의 구조와 방향족성에 대한 이론적 연구)

  • Ghiasi, Reza;Monnajemi, Majid
    • Journal of the Korean Chemical Society
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    • v.50 no.4
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    • pp.281-290
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    • 2006
  • The electronic structure and properties of the 1H-indene and mono-sila-1H-indene series have been investigated using basis set of 6-31G(d, p) and hybrid density functional theory. Basic measures of aromatic character derived from structure, molecular orbitals, a variety of magnetic criteria (magnetic isotropic and anisotropic susceptibilities) are considered. Energetic criteria suggest that In(Si7) enjoy conspicuous stabilization. However, by magnetic susceptibility isotropic this system are among the least aromatic of the family: Within their isomer series, In(Si4) is the most aromatic using this criteria. Natural bond orbital (NBO) analysis method was performed for the investigation of the relative stability and the nature of the 8-9 bonds in 1H-indene and mono-sila-1H-indene compounds. The results explained that how the p character of natural atomic hybrid orbital on X8 and X9 (central bond) is increased by the substitution of the C8 and C9 by Si. Actually, the results suggested that in these compounds, the X8-X9 bond lengths are closely controlled by the p character of these hybrid orbitals and also by the nature of C-Si bonds. The magnitude of the molecular stabilization energy associated to delocalization from X8-X9 and to * X8-X9 bond orbital were also quantitatively determined. Molecular orbital (MO) analysis further reveal that all structure has three delocalized MOs and two delocalized MOs and therefore exhibit the aromaticity.

A Study on the Social Network Characteristics in Press Organizations of Korea (국내 언론사 조직에 내재한 사회적 네트워크 특성 연구 -국민정부에서 실용정부까지 신문사와 방송사 조직에서의 밀도 및 위치 분석을 중심으로)

  • Kwon, Jang-Won
    • Korean journal of communication and information
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    • v.67
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    • pp.7-34
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    • 2014
  • This study analyzes the characteristics, implications, and problems of Social Network of Press Organizations from the Kim Dae-jung administration to the Lee Myung-bak administration in Korea. For analyzing these issues, this study attempts to investigate the traits of social network structure based on the density analysis, distribution character analysis and correspondence analysis in each and among regimes. To answer these questions, this study utilizes human relationship data which related to personal network aspects (place of birth, affiliated college) and expertise aspects (types of major field), and which data has been gathered from the biographical web-site of Press Organizations in Korea. The results showed that the membership format of each Press Organizations depends on the connection with political environment directly and indirectly. Especially, the network traits of Broadcasting Press Organizations stands out a place of birth aspect. This findings indicate that the broadcasting policy reality that the path of decision making is connected with the political environment is more effective.

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A Study on the Character and Walking Velocity of Crowd Going up Stairs (계단에서 올라가는 군집보행의 속도에 관한 조사 및 특성에 관한 연구)

  • Park, Jae-Sung
    • Fire Science and Engineering
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    • v.25 no.1
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    • pp.72-77
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    • 2011
  • The effort of transferring some parts of urban functions to the underground space is growing trend among modem cities because of the limit of horizontal land use, the rise of land value, the diversification of human desire, etc. Thus, the basement of building and the subway station have deepened. It calls our attention to safety about evacuation from the underground space to the ground. Until now, the study about crowding walk in stairs has been progressed, focusing on the crowding walk that is going down the stairs, and there is no study about crowding walk that is going up the stairs. This study measured walking pace by crowd density that is going up the stairs in the subway station stairs making one-way movement of crowd. The actual survey showed that the mathematical relation 'V=0.638-0.0949p' determines going up walking velocity at a gradient of $23^{\circ}$, and the mathematical relation will be 'V=0.597-0.1067p' at a gradient of $30^{\circ}$, when it is converted, based on the average walking velocity of crowd by the slope of the stairs which is recommended by Architectural Institute of Japan.

Clinicopathologic Features of Breast Carcinomas Classified by Biomarkers and Correlation with Microvessel Density and VEGF Expression: A Study from Thailand

  • Chuangsuwanich, Tuenjai;Pongpruttipan, Tawatchai;O-charoenrat, Pornchai;Komoltri, Chulaluk;Watcharahirun, Suwapee;Sa-nguanraksa, Doonyapat
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.3
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    • pp.1187-1192
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    • 2014
  • Background: To correlate breast cancer subtypes with prognostic factors, microvessel density (MVD), vascular endothelial growth factor (VEGF) expression and clinical features. Materials and Methods: One hundred cases of primary breast carcinoma were classified using biomarkers on tissue microarray as: luminal A [estrogen receptor (ER)+, HER2-, $Ki-67{\leq}14%$], luminal B [ER+, HER2+ or ER+, HER2-, Ki-67>14%], HER2, triple negative basal-like (TNB) [any basal cytokeratins (CKs, 5, 14, 17) and/or endothelial growth factor receptor (EGFR) expression], and TN without such markers [TNN, null], and assessed for p53, vimentin, VEGF and CD31 immunoperoxidase. Results: Of the 100 cases (mean age, 51 years; mean tumor size, 3.2cm; 56% with nodal metastasis; 89 invasive ductal carcinomas, not otherwise specified, 4 invasive lobular carcinomas, 3 metaplastic carcinomas, and 4 other types) there were 39 luminal A, 18 luminal B, 18 HER2, 15 TNB and 10 TNN. The positivities of basal-like markers in the basal-like subtype were 78.3% for CK5, 40% for CK14, 20% for CK17, 46.7% for EGFR. There was no significant difference in age distribution, tumor size, degree of tubular formation, pleomorphism, lymphovascular invasion, nodal metastasis, MVD, VEGF expression and survival among subgroups. TNs demonstrated significantly higher tumor grade, mitotic count, Ki-67 index, p53 and vimentin and decreased overall survival compared with nonTN. Conclusions: The distribution of breast cancer subtypes in this study was similar to other Asian countries with a high prevalence of TN. The high grade character of TN was confirmed and CK5 expression was found to be common in our basal-like subtype. No significant elevation of MVD or VEGF expression was apparent.

Scene Arrangement Analyzed through Data Visualization of Climax Patterns of Films (영화 클라이맥스 패턴의 데이터시각화를 통해 분석한 장면 배열)

  • Lim, Yang-Mi;Eom, Ju-Eon
    • Journal of Digital Contents Society
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    • v.18 no.8
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    • pp.1621-1626
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    • 2017
  • This study conducts data visualization of common climax patterns of Korean blockbuster films to analyze shots and evaluate scene (subplot unit) arrangement. For this purpose, a model of editing patterns is used to analyze how many climax patterns a film contains. Moreover, a system, which automatically collects shot images and classifies shot sizes of collected data, is designed to demonstrate that a single scene is composed based on a climax pattern. As a scene is a subplot and thus its arrangement cannot fully be analyzed only by climax patterns, dialogues of starring actors are also used to identify scenes, and the result is compared with data visualization results. It detects dialogues between particular actors and visualizes dialogue formation in a network form. Such network visualization enables the arrangement of main subplots to be analyzed, and the box office performance of a film can be explained by the density of subplots. The study of two types comparison analysis is expected to contribute to planning, plotting, and producing films.

Case Study of the Anti-Cholesterol Effects on the Prescription of Red Onion (적색 양파 함유 식품의 항고지혈증 효능에 대한 임상사례 보고)

  • Kim, Gyeong-Cheol;Kim, Yi-Soon
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.16 no.3
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    • pp.1-10
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    • 2012
  • Objectives: The purpose of this study is to observe clinically the anti-cholesterol effects on the prescription of red onion. Materials and methods: The subject of study were middle-aged people. We measured clinically physiological index, body composition, radial arterial pulse wave after 2 month by taking medicine (the prescription of red onion) Results: The study results were as follows. 1. Systolic and diastolic blood pressure of subjects were decreased significantly in the statistics. 2. Total cholesterol and low-density lipoprotein were decreased significantly after 2 month taking medicine. Triglyceride was decreased after 2 month but there was no significant difference and high density lipoprotein was increased after 2 month but there was no significant difference. 3. Waist-Hip ratio, body mass index and body fat percentage were decreased significantly in the statistics, after 2 month taking medicine. 4. HR was increased significantly in the statistics after 2 month but ESV and ECO were decreased signficantly in the statistics after 2 month taking medicine. 5. Pulse wave energy was increased after 2 month but there was no significant difference in the statistics. 6. RAI was decreased significantly in the statistics after 2 month taking medicine. Conclusion: The prescription of purple onion was showed significant change in physiological index, character of body composition, blood circulation index, pulse wave energy and RAI. Therefore it was showed the effect of anti-cholesterol blood circulation clinically. In the future, with diversified study on effect of prescription of purple onion, Oriental medicinal herbs will be used extensively.

Testing and evaluation of the corrosion behavior of Aluminum/Alumina bulk composites fabricated via combined stir casting and APB process

  • Abdalkareem Jasim;Ghassan Fadhil Smaisim;Abduladheem Turki Jalil;Surendar Aravindhan;Abdullah Hasan Jabbar;Shaymaa Abed Hussein;Muneam Hussein Ali;Muataz S. Alhassan;Yasser Fakri Mustafa
    • Advances in materials Research
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    • v.12 no.4
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    • pp.263-271
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    • 2023
  • In this study, AA1060/Alumina composites were fabricated by combined stir casting and accumulative press bonding (APB). The APB process was repeated up to six press bonding steps at 300Ċ. As the novelty, potential dynamic polarization in 3.5Wt% NaCl solution was used to study the corrosion properties of these composites. The corrosion behavior of these samples was compared and studied with that of the annealed aluminum alloy 1060 and versus the number of APB steps. So, as a result of enhancing influence on the number of APB process, this experimental investigation showed a significant enhancement in the main electrochemical parameters and the inert character of the Alumina particles. Together with Reducing the active zones of the material surfaces could delay the corrosion process. Also, at higher number of steps, the corrosion resistance of composites improved. The sample produced after six number of steps had a low corrosion density in comparison with high corrosion density of annealed specimens. Also, the scanning electron microscopy (SEM), was used to study the corrosion surface of samples.