Synthesis of ultra-thin tellurium nanoflakes on textiles for high-performance flexible and wearable nanogenerators

He, W.,Van Ngoc, H.,Qian, Y.T.,Hwang, J.S.,Yan, Y.P.,Choi, H.,Kang, D.J. New York] ; North-Holland 2017 APPLIED SURFACE SCIENCE - Vol.392 No.-

We report that ultra-thin tellurium (Te) nanoflakes were successfully grown on a sample of a gold-coated textile, which then was used as an active piezoelectric material. An output voltage of 4V and a current of 300nA were obtained from the bending test under a driving frequency of 10Hz. To test the practical applications, Te nanoflake nanogenerator (TFNG) device was attached to the subject's arm, and mechanical energy was converted to electrical energy by means of periodic arm-bending motions. The optimized open-circuit voltage and short-circuit current density of approximately 125V and 17μA/cm<SUP>2</SUP>, respectively, were observed when a TFNG device underwent a compression test with a compressive force of 8N and driving frequency of 10Hz. This high-power generation enabled the instantaneous powering of 10 green light-emitting diodes that shone without any assistance from an external power source.

Differences in spectroscopic characteristics between dissolved and particulate organic matters in sediments: Insight into distribution behavior of sediment organic matter

He, W.,Jung, H.,Lee, J.H.,Hur, J. Elsevier Pub.Co 2016 Science of the Total Environment Vol.547 No.-

In this study, we examined the distribution behavior of sediment organic matter (SOM) between dissolved and particulate phases and the potential influencing factors by comparing the spectroscopic features of pore water organic matter (PWOM) and alkaline-extractable organic matter (AEOM) of river sediments. The characteristics of SOM were described by several selected spectral indicators and fluorescence excitation emission matrix (EEM)-parallel factor analysis (PARAFAC). The spectral indicators showed that larger sized SOM molecules with a higher aromatic content were more enriched in sediment particles than in pore water. The relative ratios of humification index between dissolved and particulate phases revealed that the SOM constituents with a higher degree of structural condensation were preferentially distributed onto sediment particles. EEM-PARAFAC demonstrated different distribution behaviors of protein-like (tyrosine-like and tryptophan-like) and humic-like substances in sediments. The relative abundance of tyrosine-like component was much higher in PWOM than in AEOM, whereas the other three components tended to be more abundant in AEOM. The predominant presence of tyrosine-like component suggests its potential operation as a discriminant indicator between PWOM and AEOM. Spearman correlations and non-metric multidimensional scaling further revealed that distribution of protein-like components onto sediment particles might be associated with reductive environments, aluminum minerals, and anthropogenic activities of upstream watersheds. This study demonstrated a successful application of using EEM-PARAFAC to examine the distribution behavior of different SOM constitutes between dissolved and solid phases.

Effects of high soil CO₂ concentrations on seed germination and soil microbial activities

He, W.,Moonis, M.,Chung, H.,Yoo, G. Elsevier BV 2016 INTERNATIONAL JOURNAL OF GREENHOUSE GAS CONTROL Vol.53 No.-

To ensure the safety of carbon capture and storage (CCS) technology, we assessed the impacts of potential CO<SUB>2</SUB> leakage on the soil and ecosystem by performing laboratory experiments. In particular, we investigated the effects of high soil CO<SUB>2</SUB> concentration on germination rates of four different plant species and soil physicochemical/microbial parameters. Cabbage, corn, bean, and wheat were exposed to different soil CO<SUB>2</SUB> concentrations (LOW: 3.5%, MEDIUM: 12.0%, HIGH: 29.4%, EXTREME: 52.9%). Soil pH and O<SUB>2</SUB> concentration decreased sharply immediately after the gases were injected. Final germination rates were not affected by LOW CO<SUB>2</SUB> treatment, but the germination of cabbage, corn, and bean was delayed. Germination of all plants was retarded by MEDIUM CO<SUB>2</SUB> treatment. No seeds were germinated when exposed to HIGH or EXTREME CO<SUB>2</SUB>. The contents of soil total C, total N, and soil microbial activities were not affected by CO<SUB>2</SUB> injection. Our results suggest that a soil CO<SUB>2</SUB> concentration of 3-4% does not inhibit germination. Wheat was the most resistant plant of those exposed to high CO<SUB>2</SUB> concentrations. Soil microbial parameters were tolerant to short-term CO<SUB>2</SUB> injection. We conclude that CO<SUB>2</SUB> leakage with high concentration (>30%) can have a severe effect on seed germination, but soil microbial activity was not affected by short-term exposure.

내고장 학교급식의 운영모형 개발

최휴종 한국관광정책학회 2001 觀光政策學硏究 Vol.7 No.3

Recently, the school catering is attracting public attention as its level of menu, nutrition, sanitation, plays an important part of our national health. The objective of this study is to to build a model for appropriate school catering system and its fund raising. The principal finding of this study are summarized as follows. First, the selection of catering management method among self-managing method, consignment managing method, facility consignment managing method, buying-meal method depends on the financial conditions, volume of one time-catering, etc.. Second, the enlarging of educational grant, budget convertion, the revision of relative laws and regulations are needed to raise the fund for the school catering facilities. Third, purching-meals method with outdoor private food service company is better to small size school.

공항 리무진버스 운행의 성과측정 방안

최휴종 한국관광정책학회 2000 觀光政策學硏究 Vol.6 No.3

The transportation work from airport to hotel in the Seoul and neighboring districts plays very important role in foreign tourists' image on the Korea. The deficit-ridden line of airport limousine bus causes the dispute of deficit covering intervened by public institutions. But the intervention of public institutions should be done caustiously and based on the objective performance evaluation. The objective performance evaluation of airport limousine bus may be obtained to use Customer Utilization Indicator (CUI) and Transit Performance Inclicutor(TPI) proposed by this paper.

관광정책의 개발모형에 관한 연구

최휴종 한국관광정책학회 1999 觀光政策學硏究 Vol.5 No.2

The development of tourism raises substantial policy issues. Four reasons for this are market failure, dependency on externalities, significant impact on environment, conflict of interests in tourism industry. The economic approach assumes a policy making framework. operated by selfless individuals pursing public interest and appraises budgeting programs by economic method as follows : the expenditure macro-model, the input-output model, the linear programming model. A new approach based on exchange theory applies the concepts of self-interest and exchange theory to the tourism policy development. The groups interested in tourism policies are assumed to try to influence tourism policies in their favor and purse their own self-interests by lobbying political parties and making a compromise.

항공레저·스포츠 산업의 구조분석과 진흥모형

최휴종 경희대학교 산업관계연구소 2009 産硏論叢 Vol.34 No.-

본 연구는 최근 증가되는 우리나라 항공 레저·스포츠 산업의 수요증가 추세에 따라 항공 레저․스포츠 산업의 구조 분석과 발전전략의 틀을 제시하고자 하였다. 우선 주제에 따라 노정되는 문제의 제기를 하였으며 제기된 문제를 해결하고자 이론적인 연구와 현장자료의 수집을 동시에 진행 하였다. 연구결과 산업의 산업경쟁력 요인은 안전 시스템, 교육․훈련, 시설, 가격, 접근 편리성, 조망․경치 등 6가지 요인으로 정리 되었으며 종목별로 위험과 이용면에서 다양한 스펙트럼을 보이는 것으로 파악 되었다. 항공 레저․스포츠 산업의 산업 수요는 크게 증가되어 2020년에는 약 1,400억원에 이를 것으로 전망 되었으며 수요를 충족 시키기 위하여 스포츠형과 유람형의 균형잡힌 발전 모형을 제시 하였다. 일본 , 호주, 중국 등의 산업 현황을 비교 분석하여 우리나라에 적용할 수 있는 세부적인 계획을 고안 하였다. Air- leisure&sports is nowadays getting popular as most people prefer experience activity. Ultra light airline, sky diving, paragliding, motor paragliding, hang gliding, air balloon, sports kite, model airplane are examples for air- leisure&sports and at this stage a few sector are developed except Paragliding and Hanggliding in South Korea. This study reveals that the market volume will be one hundred million dollars in 2020 years and suggests that balanced development strategies for air sports and air leisure will be required.

내고장 관광지 탐방프로그램 개발 및 실행방안

최휴종 한국관광정책학회 2001 觀光政策學硏究 Vol.7 No.1

Recently, The introduction of the tourism trail program about residential areas to elementary school curriculum is needed as the tourism become a part of daily life. The tourism trail program is designed to guide elementary school students in knowing and feeling proud about their living places. The conclusion and implications of this paper are as follows: First, The structure of trail, resources, sign, subsidiary facilities, operation method are important in developing the tourism trail of living places. Second, The reciprocal education method and learning attitudes through inquiry activities improve students' understanding of and their taking pride in their living places. Third, The matching funding system between provincial government communities is required for The effective introduction of the tourism trail program.

관광기업의 성과측정 모형 개발

최휴종 한국관광정책학회 2003 觀光政策學硏究 Vol.9 No.2

Recertly, the regional government offices are planning to make incentive system for travel agents to take package tourists their regional areas as the importance of their regional tourism revenue increases. The objective of this study is to build a model for evaluating the performance of travel agents on regional areas. The evaluation of travel agents performance on regional areas should be based on performance criteria such as Sales Increase Indicator(SII), Companies' Satisfation Indicator(CSI), etc.,

Methicillin-내성 황색포도상구균의 각종 항균제에 대한 내성양상과 Plasmid DNA의 특성

정선식,신종희,류필열,안태휴,양동욱,김영일,이준행,김영휴 대한감염학회 1995 감염 Vol.27 No.1

광주지역의 A병원과 B병원에 입원한 환자의 각종 임상가검물로 부터 분리동정한 황색포도상구균 251주를 19종의 항균제에 대한 감수성 검사를 실시하고 내성인자를 조사하여 다음과 같은 결과를 얻었다. Oxacillin에 대한 내성빈도는 A병원에서 74.2%로 B병원의 46.1% 보다 약 30% 정도가 높았다. 또한 cephalosporine계 항균제와 aminoglycoside계 약제에 대한 내성빈도는 A 병원 분리균주에서 높은 경향을 보였으며, ampicillin(Amc), tetracycline(Tc), chloram-phenicol(Chp), ciprofloxacin(Cpfx)등의 항균제에 대한 내성빈도는 A병원와 B병원에서 분리된 균주간에 유사하였다. 그러나 fosfomycin(Fom)에 대한 내성빈도는 오히려 B병원 분리균주에서 높았다. 10가지 이상의 약제에 내성을 갖는 다제내성균의 출현율은 B병원에서 보다 A병원에서 높았다. A병원와 B병원에서 분리된 MRSA 대부분이 cefamandole(Cmdl)을 제외한 cephalosporin계 약제와 aminoglycoside제제에 대해 내성을 나타내었으며, netilmicin(Net) 과 rifampin(Rfp)에 대한 내성빈도는 A병원에서 분리된 균주에서 높았으며 Fom, Tc, Chp에 대한 내성빈도는 오히려 B병원에서 분리된 MRSA 에서 높았다. 다제내성균의 출현율은 두 병원간에 큰차이가 없었다. MRSA 의 다제내성양상은 Fom, Net, Chp 및 Rfp에 대한 내성에 따라 A병원와 B병원에 서 분리된 균주간의 차이가 관찰되었는데, A병원에서 가장 많이 나타난 내성유형은 AmcCtxCzolLmoxGmTobLcmAmkNetTcEmRfp 및 AmcCtxCzolCmdlLmoxFomGmTobLcmAmkNetTcEmRfp에 중복내성을 갖는 균주가 각각 12균주로 가장 많았으며 B병원에서 분리된 균주에서 많이보이는 내성유형은 AmcCtxCzolLmoxFomGmTobLcmAmkChpTcEm에 중복내성은 갖는 균주가 11주로 가장 많았다. 두 병원에서 분리된 균주 모두 β-lactam계 약제와 aminoglycoside계 약제간의 교차내성을 가지고 있었다. MRSA균주에서 분리한 plasmid DNA profile은 A병원와 B병원에서 분리된 균주에서 약제에 대한 다제내성양상에 따라 차이가 있었으며, A병원 분리균주에서는 108kb, B병원 분리균주에서는 2.8kb의 plasmid를 보유하는 차이가 있었다. Background: Increased isolation of methicillin-resistant Straphylococcus aureus has become one of the important problem in treating staphylococcal infections. The aim of the study was to investigate the epidemiological characteristics of antimicrobial resistance of MRSA's isolated in the Kwangju area. Methods: 251 strains of S. aureus were isolated from various specimens from A-hospital and B-hospital and there resistance patterns against 19 antimicrobial agents and plasmid profiles studied. Results: Methicillin resistance was detected in 74.2% and 46.1% of A-hospital and B-hospital isolates, respectively. Resistance to cephalosporins and aminoglycosides was more frequent in the A-hospital isolates than in the B-hospital isolates, whereas fosfomycin resistance was more frequent in the B-hospital isolates than in the A-hospital isolates. Frequency of resistance to ampicillin, tetracycline, chloramphenicol, ciprofloxacin in A-hospital isolates was similar to B-hospital isolates. Strains with multiple resistance to more than 10 drugs were more frequent in the A-hospital isolates than that in the B-hospital isolates. Among MRSA strains, resistance to netilmicin and rifampin was more frequently encountered in A-hospital isolates, while resistance to fosfomycin, tetracyclin, and chloramphenicol was more frequent in B-hospital isolates. No differences in resistance patterns against other cephalosporins and aminoglycosides were observed between the two hospitals. Fosfomycin, netilmicin, chloramphenicol and rifampin resistances were different between the hospitals in strains with multiple resistance. The most frequently observed multiple resistance patterns observed among A-hospital isolates were AmcCtxCzoILmoxGmTobLcmAmkNetTcEmRfp and AmcCtxCzolCmdlLmoxFomGmTobLcmAmkNetTcEmRfp. Among B-hospital isolates, AmcCtxCzolLmoxGmTobLcmAmkChpTcEm pattern was the most frequent. Conclusion: MRSA strains from both hospitals showed cross-resistance to β-lactams and aminoglycosides. Plasmid profiles from MRSA strains were different, according to the multiple resistance patterns. Characteristically, 108 kb plasmid was detected only in A-hospital-MRSA strains, while 2.8 kb plasmid was detected only in B-hospital-MRSA strains.