• 제목/요약/키워드: International School

검색결과 9,266건 처리시간 0.05초

Performance predictions and acoustic analysis of the HVAB rotor in hover

  • Mali, Hajar;Benmansour, Kawtar;Elsayed, Omer;Qaissi, Khaoula
    • Advances in aircraft and spacecraft science
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    • 제9권4호
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    • pp.319-333
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    • 2022
  • This work presents a numerical investigation of the aerodynamics and aero acoustics of the HVAB rotor in hover conditions. Two fully turbulent models are employed, the one-equation Spalart-Allmaras model and the two-equation k-ω SST model. Transition effects are investigated as well using the Langtry-Menter γ-Re θt transition transport model. The noise generation and propagation are being investigated using the Ffows-Williams Hawking model for far-field noise and the broadband model for near-field noise. Comparisons with other numerical solvers and with the PSP rotor test data are presented. The results are presented in terms of thrust and power coefficients, the figure of merit, surface pressure distribution, and Sound pressure level. Velocity, pressure, and vortex structures generated by the rotor are also shown in this work. In addition, this work investigates the contribution of different blade regions to the overall noise levels and emphasizes the importance of considering specific areas for future improvements.

Molecular Cloning and Characterization of a Novel Stem-specific Gene from Camptotheca acuminata

  • Pi, Yan;Liao, Zhihua;Chai, Yourong;Zeng, Hainian;Wang, Peng;Gong, Yifu;Pang, Yongzhen;Sun, Xiaofen;Tang, Kexuan
    • BMB Reports
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    • 제39권1호
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    • pp.68-75
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    • 2006
  • In higher plants, P450s participate in the biosynthesis of many important secondary metabolites. Here we reported for the first time the isolation of a new cytochrome P450 cDNA that expressed in a stem-specific manner from Camptotheca acuminata (designated as CaSS), a native medicinal plant species in China, using RACE-PCR. The full-length cDNA of CaSS was 1735 bp long containing a 1530 bp open reading frame (ORF) encoding a polypeptide of 509 amino acids. Bioinformatic analysis revealed that CASS contained a heme-binding domain PFGXGRRXCX and showed homology to other plant cytochrome P450 monooxygenases and hydroxylases. Southern blotting analysis revealed that there was only one copy of the CaSS present in the genome of Camptotheca acuminata. Northern blotting analysis revealed that CaSS expressed, in a tissue-specific manner, highly in stem and lowly in root, leaf and flower. Our study suggests that CaSS is likely to be involved in the phenylpropanoid pathway.

국내공립학교의 국제인증기준과 단위공간구성에 관한 연구 (A Study on the International Accreditation Standard and Unit Spatial Organization of Public School in Korea)

  • 이을규;전유창
    • 교육시설 논문지
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    • 제23권1호
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    • pp.13-22
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    • 2016
  • Recently, Korea has been established and operated International Schools manifesting to improve the nation's capacity of the foreign languages skill and to cultivate internationally trained professional manpower. In order to achieve the vision of a world-class educational organization, it has to be designed for the facility standards to meet the international accreditation standards. Therefore, the main purpose of this study is to research about basic resources through comparison of facility conditions between public schools in Korea and international accredited schools. By comparing those two different plan drawings are found the following things. First, Schools which established with International Accreditation Standard are prepared detailed criteria for the facility, Furthermore information about the furnishings included, in addition to specific equipments for classes are stated to be prepared. Secondly, it is more effective when special classrooms such as music and science are equipped with various spatial elements, enough educational equipment storage, teacher's study rooms, practical training rooms and student's activity rooms to support various teaching programs and learning efficiently. Lastly, there was a clear tendency that not only hardware but also software standards for the audiovisual room and library have been more enhanced to enable multidisciplinary educational approaches with the recent education training trend.

Evaluating the Competitiveness of Cargo Airports using Best-Worst Method

  • Sara Shishani;Young-Joon Seo;Seok-Joon Hwang;Young-Ran Shin;A-Rom Kim
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2022년도 춘계학술대회
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    • pp.204-206
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    • 2022
  • The global economy and the air transport business have been affected since the spread of the COVID-19 pandemic. As countries tighten restrictions on international movements, the growing emphasis on air cargo puts pressure on airports to maintain and upgrade their cargo policies, facilities, and operations. Hence, ensuring the competitiveness of cargo airports becomes pivotal for airports survival under the volatile global demand. The study aims to evaluate the importance of the competitiveness factors for cargo airports and identify areas for further improvement. The study applies the Best-Worst Method (BWM) to assess the cargo airports' competitiveness factors: 'Transport Capacity,' 'Airport Operations and Facility Capacity,' 'Economic Growth,' 'Financial Performance,' and 'Airport Brand Value.' The selected airports include Heathrow Airport, Aéroport de Paris-Charles de Gaulle, Hong Kong International Airport, and Incheon International Airport. The results identify 'Transport Capacity' as the most significant competitiveness factor, and Hong Kong International Airport the best performing cargo airport. This research forms a reference framework for evaluating cargo airports' competitive position, which may help identify airports' relative strengths and weaknesses. Moreover, this framework can also serve as a tool facilitating the strategic design of airports that may accommodate both air cargo and passenger demand flexibly under the demand uncertainty.

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Photocatalytic Systems of Pt Nanoparticles and Molecular Co Complexes for NADH Regeneration and Enzyme-coupled CO2 Conversion

  • Kim, Ellen;Jeon, Minkyung;Kim, Soojin;Yadav, Paras Nath;Jeong, Kwang-Duk;Kim, Jinheung
    • Rapid Communication in Photoscience
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    • 제2권2호
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    • pp.42-45
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    • 2013
  • Natural photosynthesis utilizes solar energy to convert carbon dioxide and water to energy-rich carbohydrates. Substantial use of sunlight to meet world energy demands requires energy storage in useful fuels via chemical bonds because sunlight is intermittent. Artificial photosynthesis research focuses the fundamental natural process to design solar energy conversion systems. Nicotinamide adenine dinucleotide ($NAD^+$) and $NADP^+$ are ubiquitous as electron transporters in biological systems. Enzymatic, chemical, and electrochemical methods have been reported for NADH regeneration. As photochemical systems, visible light-driven catalytic activity of NADH regeneration was carried out using platinum nanoparticles, molecular rhodium and cobalt complexes in the presence of triethanolamine as a sacrificial electron donor. Pt nanoparticles showed photochemical NADH regeneration activity without additional visible light collector molecules, demonstrating that both photoactivating and catalytic activities exist together in Pt nanoparticles. The NADH regeneration of the Pt nanoparticle system was not interfered with the reduction of $O_2$. Molecular cobalt complexes containing dimethylglyoxime ligands also transfer their hydrides to $NAD^+$ with photoactivation of eosin Y in the presence of TEOA. In this photocatalytic reaction, the $NAD^+$ reduction process competed with a proton reduction.

Root canal irrigants influence the hydrophobicity and adherence of Staphylococcus epidermidis to root canal dentin: an in vitro study

  • Nagendrababu, Venkateshbabu;Sultan, Omer Sheriff;Kannathasan, Sreedharan;Patel, Amir Shahreza;Chitra, Ebenezer;Neelakantan, Prasanna;Davamani, Fabian
    • Restorative Dentistry and Endodontics
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    • 제43권1호
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    • pp.1.1-1.8
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    • 2018
  • Objectives: To determine the effect of root canal irrigants on the hydrophobicity and adherence of Staphylococcus epidermidis (S. epidermidis) to root canal dentin in vitro. Materials and Methods: Root dentin blocks (n = 60) were randomly divided into 4 groups based on the irrigation regimen: group 1, saline; group 2, 5.25% sodium hypochlorite (NaOCl); group 3, 5.25% NaOCl followed by 17% ethylenediaminetetraacetic acid (EDTA); group 4, same as group 3 followed by 2% chlorhexidine (CHX). The hydrophobicity of S. epidermidis to root dentin was calculated by cell surface hydrophobicity while the adherence was observed by fluorescence microscopy, and bacteria were quantified using ImageJ software (National Institutes of Health). Statistical analysis of the data was done using Kruskal-Wallis test and Mann-Whitney U test (p = 0.05). Results: The hydrophobicity and adherence of S. epidermidis to dentin were significantly increased after irrigating with group 3 (NaOCl-EDTA) (p < 0.05), whereas in group 4 (NaOCl-EDTA-CHX) both hydrophobicity and adherence were significantly reduced (p < 0.05). Conclusions: The adherence of S. epidermidis to dentin was influenced differently by root canal irrigants. Final irrigation with CHX reduces the bacterial adherence and may impact biofilm formation.

Factors Affecting Logistics Capabilities for Logistics Service Providers: A Case Study in Vietnam

  • DANG, Dinh Dao;HA, Dieu Linh;TRAN, Van Bao;NGUYEN, Van Tuan;NGUYEN, Thi Lien Huong;DANG, Thuy Hong;LE, Thi Thai Ha
    • The Journal of Asian Finance, Economics and Business
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    • 제8권5호
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    • pp.81-89
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    • 2021
  • This study aimed to investigate the factors affecting Logistics capabilities for Logistics Service Providers in Vietnam. Researchers inherited and developed based on previous research to focus on analyzing and evaluating dynamics, measuring Logistics capabilities, and the factors affecting Logistics capabilities for Logistics Service Providers. The logistics capabilities Model is used based on three factors: customer demand management capability, innovation capability, and information management capability. The empirical analysis used data from the survey data of l90 managers of Logistics Service Providers in Hai Phong, Ho Chi Minh City, Da Nang, Hue, Hanoi with reliable tools (SPSS 26.0 software). The data were analyzed by frequencies, percentages, means, Pearson's Linear Correlation Coefficient, exploratory factor analysis, and multi-linear regression model based on the survey data. The research results identified the following factors affecting Logistics capabilities for Logistics Service Providers: innovation capability has the strongest impact on Logistics capabilities; customer demand management capability has the following strong effects on Logistics capabilities; and finally, information management capability that affects Logistics capabilities. There is also a positive relationship between all factors and Logistics capabilities. Several recommendations are further suggested to enhance to improve Logistics capabilities for Logistics Service Providers in Vietnam.