• 제목/요약/키워드: CWC

검색결과 70건 처리시간 0.022초

지표면 Wetness에 따른 오존의 건성침적속도 특성 (The Characteristics of the Dry Deposition Velocity for O3 regarding Surface Wetness)

  • 이화운;김유근;문난경
    • 한국환경과학회지
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    • 제12권4호
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    • pp.393-397
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    • 2003
  • It has been researched the relationship between deposition velocity and factors which could affect the deposition phenomena and deposition velocity also has been estimated fer several land-use types. The typical deposition velocities are complex functions of surface types, atmospheric stabilities, friction velocities, air pollutants and so on. The canopy resistance is major contribution to the model's total resistance for O₃. Canopy wetness is also an important factor to calculate deposition velocity. We considered the canopy wetness as canopy water content(CWC) in our Model. But, it is not easy to observe CWC over each land-use types. In this study, we use CWC observed by EMEFS(CANADA Environment Service, 1988) to examine the influence of CWC in estimation of 03 dry deposition velocity(V/sub d/) in summertime. The value of O₃ V/sub d/ range 0.2 ∼ 0.7 cm s/sup -1/ on dry surface and 0.01 ∼ 0.35 cm s/sup -1/ on wet surface in daytime.

The effects of the circulating water tunnel wall and support struts on hydrodynamic coefficients estimation for autonomous underwater vehicles

  • Huang, Hai;Zhou, Zexing;Li, Hongwei;Zhou, Hao;Xu, Yang
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제12권1호
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    • pp.1-10
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    • 2020
  • This paper investigates the influence of the Circulating Water Channel (CWC) side wall and support struts on the hydrodynamic coefficient prediction for Autonomous Underwater Vehicles (AUVs) experiments. Computational Fluid Dynamics (CFD) method has been used to model the CWC tests. The hydrodynamic coefficients estimated by CFD are compared with the prediction of experiments to verify the accuracy of simulations. In order to study the effect of side wall on the hydrodynamic characteristics of the AUV in full scale captive model tests, this paper uses the CWC non-dimensional width parameters to quantify the correlation between the CWC width and hydrodynamic coefficients of the chosen model. The result shows that the hydrodynamic coefficients tend to be constant with the CWC width parameters increasing. Moreover, the side wall has a greater effect than the struts.

해양공학용 소형 회류수조 설계 및 성능분석 (Design and Performance Analysis of a Small Circulating Water Channel for Ocean Engineering)

  • 임영배;정우철;박찬원;홍기섭
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2003년도 춘계학술대회 논문집
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    • pp.198-202
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    • 2003
  • A small circulating water channel (CWC) for experiments ocean engineering is designed and made through the co-work of a company, MESTEC, and a college, Inha Technical Research Institute. General function of the elements of CWC are explained. The velocities in the test section are measured and analysed to estimate the performance of the CWC. The result of the velocity distribution is acceptable for experiments of ocean engineering.

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은처리 세라믹과 키틴을 첨가한 LDPE 필름을 이용한 딸기의 저장 (Storage of Strawberries Using Low Density Polyethene Film Filled with Silver-coated Ceramic and/or Chitin)

  • 은종방;김종대
    • 한국식품저장유통학회지
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    • 제4권3호
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    • pp.251-258
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    • 1997
  • The quality changes of strawberries packaged using low density polyethylene (LDPE) film filled with 3% silver-coated ceramic (WC30) and filled with it and 0.1% chitin (CWC) were investigated during storage at 2$0^{\circ}C$ for 5 days. In gas composition within film bag, CWC and WC30 kept higher CO2 concentration than LDPE without silver-coated ceramic and chitin (CO) did during 5 day storage. The weight loss of strawberries during storage was the smallest in WC30 and the largest in CWC in 5 days. Hardness of strawberries was the highest in WC30 and the lowest in CO during 5 day storage. pH of strwberries was increased a little until 1 day and was not changed after 1 day storage, and soluble solid content was not changed during storage. Vitamin C content was decreased significantly until 2 day storage and decreased a little after 2 days. There is no differences in the change of vitamin C content among the packaging materials. In color measurement, lightness was the highest in WC 30 and in sensory evaluation, all characteristics also had the highest scores in WC30. In conclusion, better quality of straberries was shown in WC30 than in CWC and CO during storage.

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대장암 생존자에게 적용한 전문간호사 주도 심리교육 프로그램의 효과 (Effects of the Advanced Practice Nurse-Led Psychoeducational Program for Colorectal Cancer Survivors)

  • 김혜경;유양숙
    • 대한간호학회지
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    • 제52권3호
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    • pp.245-260
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    • 2022
  • Purpose: This study aimed to investigate the effects of an advanced practice nurse-led psychoeducational program on distress, anxiety, depression, coping with cancer (CWC), health promotion behavior (HPB), and quality of life (QOL) among colorectal cancer survivors. Methods: This study was designed as a quasi-experimental study with a non-equivalent control group pretest-posttest. The participants were survivors of colorectal cancer who underwent follow-up care. There were 39 survivors: 19 in the experimental group and 20 in the control group. The experimental group performed a psychoeducational program for 120 minutes per session, once a week for a total of six weeks, while the control group received routine education and counseling. Distress, anxiety, depression, CWC, HPB, and QOL were investigated before, immediately after, and 4 weeks after the intervention. The data were analyzed with SPSS/WIN ver. 24.0, using repeated measures ANOVA. Results: There were significant interactions between time and group for distress and anxiety. In addition, CWC interacted with the total of CWC and interpersonal coping, and QOL interacted with the total of QOL and functional status. However, there were no significant differences in the depression or HPB scores. Conclusion: Based on the results of this study, we expect that this program can be used as an effective intervention for colorectal cancer survivors.

회류수조에서의 ABS에 의한 활주선 후류 기포항적계측 (Bubble Wake Measurement by Acoustic Bubble Spectrometer Generated by Planing Hull at Circulating Water Channel)

  • 신명수;문일성;나영인;박종천
    • 한국군사과학기술학회지
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    • 제14권1호
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    • pp.55-61
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    • 2011
  • This paper presents bubble wake measurement results generated by the planing hull. The bubble was generated by SNAME TMB model(No. 4876) with hard chine at the CWC(Circulating Water Channel). ABS(Acoustic Bubble Spectrometer) was used to measure bubble wake measurement. The manufactured model is one meter in length and uniform velocity to generate the bubble at CWC is 3m/s, relatively higher speed than conventional hull form. Measurements were performed successfully and measured results show well the general characteristics of bubble wake generated by planing hull. Furthermore, experimental equations are proposed for the practical use.

PIV를 사용한 2차원 원형 실린더 주위의 유동해석 (Flow Survey around Two-Dimensional Circular Cylinder using PIV Technique)

  • 박건선;곽영기
    • 한국해양공학회지
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    • 제18권3호
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    • pp.1-7
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    • 2004
  • Flaw visualization and velocity field measurement methods have practical applications in the various fluid engineering fields, such as mechanics, ships, and heat fluids. In this study, the basic principles and theoretical methods are used to establish an application technique of Particle Imae Velocimetry(abbreviated to PIV below). Accordingly, the measured results of velocity field distribution of a section inside the Circulating Water Channel (abbreviated to CWC below) are computed using the PIV is presented. The uniformity of velocity distribution of the section in CWC is confirmed, by comparing this PIV data with the existing current meter data. Also, in order to measure the flaw fields of surroundings of 2-dimensional cylinder in the CWC, the flaw visualization technique using the PIV is applied.

한약재 4종 복합추출물의 해마신경세포 보호를 통한 기억력 개선 (New Four-herb Formula Ameliorates Memory Impairments via Neuroprotective Effects on Hippocampal Cells)

  • 안성민;최영완;신화경;최병태
    • 생명과학회지
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    • 제26권4호
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    • pp.475-483
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    • 2016
  • 본 연구는 동의보감을 근거로 선별된 백수오, 지황, 원지 및 석창포로 구성된 복합추출물의 해마신경세포에 대한 보호 및 기억력의 개선효과를 살펴보았다. 복합추출물의 신경보호효과를 검증하기 위해 HT22해마신경세포의 생존율, 세포독성 및 활성산소를 분석하였으며, 허혈성 뇌손상 마우스모델을 이용하여 기억에 대한 동물행동학적 변화와 단백질 발현을 측정하였다. 해마신경세포에서 복합추출물의 전 처리는 glutamate에 의해 유도된 활성산소의 축적을 억제하였으며 세포사멸을 감소시켰다. 허혈성 뇌손상 마우스모델에서 복합추출물은 동물행동학적으로 공간 및 단기 기억능력을 개선시켰다. 뇌허혈로 인해 증가된 p38 MAPK의 인산화는 복합추출물에 의해 현저히 감소하는 반면, 감소된 PI3K와 CREB의 인산화는 현저히 증가하였다. 이를 면역조직화학분석을 통해 복합추출물을 투여한 그룹이 해마에서 발현되는 CREB의 인산화가 현저히 증가되는 것을 확인하였다. 이상의 결과는 복합추출물이 CREB 단백질과 관련된 신경보호 신호기전을 조절함으로써 인지기능을 개선시키는 것으로 사료된다.

금속 밀링과 직접 금속 레이저 소결 방식으로 제작한 3본 코발트-크롬 구조물의 변연 및 내부 적합도 비교 평가 (Comparative evaluation of marginal and internal fit of three-unit Co-Cr frameworks fabricated by metal milling and direct metal laser sintering methods)

  • 안재석;이정환
    • 대한치과기공학회지
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    • 제42권2호
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    • pp.81-89
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    • 2020
  • Purpose: This in vitro study was conducted to evaluate the marginal and internal fit of three-unit Co-Cr frameworks fabricated by computer-aided metal milling and direct metal laser sintering(DMLS) systems in comparison to conventional casting method. Methods: Three-unit Co-Cr frameworks were fabricated by conventional wax up with casting(CWC), computer-aided metal milling(MM) and direct metal laser sintering(DMLS)(n=10 each). The marginal and internal fit of specimens were examined using a light-body silicone impression material. The thickness of light-body silicone was measured at eight reference points each, divided in the mesio distal and bucco lingual directions. All measurements were conducted by a stereomicroscope. Digital photos were taken at 150× magnification and then analyzed using a measurement software. The Kruskal-Wallis test and Bonferroni correction were used for analyzing the results. Results: The mean(SD) is ㎛ for fabrication methods, the mean marginal fit were recorded respectively, DMLS 39(27), followed by CWC 63(38), MM 220(128). and the mean internal fit CWC 95(47), DMLS 116(49), MM 210(152). In addition, the largest gap was found in the occlusal surface area among the internal measurement areas of all groups. Conclusion: As a result, the direct metal laser sintering method showed better marginal and internal fit than the metal milling method. The marginal and internal fit were statistically different according to the three fabrication methods(p<0.001). Except the MM group, the marginal fit of the CWC and DMLS groups was below the clinical standard of 120 ㎛. Based on the results of this study, it can be applied to clinical use in the future.

왁스 밀링 방법 및 디지털 광 프로젝션 방법으로 제작된 3본 금속 구조물의 적합도 비교 (Comparison the fit of three-unit metal framework fabricated by wax milling method and digital light projection method)

  • 이정환;안재석
    • 대한치과기공학회지
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    • 제41권1호
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    • pp.9-19
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    • 2019
  • Purpose: This study was conducted to comparative evaluate the marginal and internal gap of three-unit metal frameworks(Co-Cr) fabricated by wax milling method and digital light projection method of CAD/CAM systems. Methods: All the specimens were fabricated by three different fabrication methods: conventional wax up with casting(CWC), milled wax block with casting(MWC), digital light projection with casting(DLPC) (n=10 each). The marginal and internal fits of specimens were examined using a replica technique. The light-body silicone thickness was measured at 8 reference points(each abutment: 16 measurements). All measurements were conducted by a stereomicroscope. Digital photo were taken at $150{\times}$ magnification and then analyzed using a measurement software. The Mann-Whitney test was used for analyzing the results. Results: Statistically significant differences were found between the fabrication methods(p<0.001). The mean(SD) is ${\mu}m$ for fabrication methods, the mean marginal fit were recorded respectively, CWC 63(38), MWC group 50(33), DLPC 103(54) and the mean internal fit CWC 96(47), MWC group 116(41), DLPC 138(66). Conclusion : The marginal and internal fit were statistically different according to the fabrication methods(p<0.001). In all fabrication methods, the greatest misfit was found the occlusal area of all specimens.