• Title/Summary/Keyword: 비정상 유체력

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Suspension of Sediment over Swash Zone (Swash대역에서의 해빈표사 부유거동에 관한 연구)

  • Cho, Yong Jun;Kim, Kwon Soo;Ryu, Ha Sang
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.1B
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    • pp.95-109
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    • 2008
  • We numerically analyzed the nonlinear shoaling, a plunging breaker and its accompanying energetic suspension of sediment at a bed, and a redistribution of suspended sediments by a down rush of preceding waves and the following plunger using SPH with a Gaussian kernel function, Lagrangian Dynamic Smagorinsky model (LDS), Van Rijn's pick up function. In that process, we came to the conclusion that the conventional model for the tractive force at a bottom like a quadratic law can not accurately describe the rapidly accelerating flow over a swash zone, and propose new methodology to accurately estimate the bottom tractive force. Using newly proposed wave model in this study, we can successfully duplicate severely deformed water surface profile, free falling water particles, a queuing splash after the landing of water particles on the free surface and a wave finger due to the structured vortex on a rear side of wave crest (Narayanaswamy and Dalrymple, 2002), a circulation of suspended sediments over a swash zone, net transfer of sediments clouds suspended over a swash zone toward the offshore, which so far have been regarded very difficult features to mimic in the computational fluid mechanics.

DNA Ploidy as a Predictive Index of Therapeutic Response in Lung Cancer (폐암환자에서 치료에 대한 반응 예측지표로서의 DNA Ploidy)

  • Choi, In-Seon;Lee, Shin-Seok;Yang, Jae-Beom;Park, Kyung-Ok;Jung, Sang-Woo
    • Tuberculosis and Respiratory Diseases
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    • v.39 no.2
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    • pp.150-158
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    • 1992
  • Background: Although many authors have reported that the median survival time of surgically resected non-small cell lung cancer (NSCLC) was shorter in aneuploid than in diploid determined by flow cytometry, there are few reports about DNA ploidy using bronchial brushing material in all types of lung cancer. Method: The DNA ploidy test results of 109 consecutive patients with lung cancer were analyzed to find the relationship of DNA ploidy and anatomic or physiologic stage. And the differences of the response to various therapeutic modalities according to DNA ploidy were evaluated at least 8 weeks after the begining of the therapy. Results: Numbers of patients with DNA aneuploid pattern or high proliferative activity (S+G2M>22%) were not different among the various cell types of lung cancer. The relationship of DNA ploidy and anatomic or physiologic stage was not significant. However, NSCLC patients with high proliferative activity showed more advanced anatomic stage than those without that (p<0.05). The short-term response rate to therapy depended on the anatomic (p<0.005) or physiologic stages (p<0.05) in patients with NSCLC, and not on DNA ploidy or proliferative activity. Conclusion: DNA ploidy test using bronchial brushing material revealed that high proliferative activity means advanced anatomic stage, but it was not useful to predict the therapeutic response.

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A numerical study on the unsteady agglomeration behavior of algae in the ultrasonic wave pressure field (초음파 압력장에서 미세조류 응집 거동에 관한 비정상상태 수치해석 연구)

  • Ha, Ji Soo;Shim, Sung Hun;Jung, Sang Hyun
    • Journal of Energy Engineering
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    • v.26 no.4
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    • pp.67-73
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    • 2017
  • For the bio-fuel conversion of algae, several processes are needed including cultivating, agglomeration, extracting and conversion to the bio-fuel. The production cost for each process makes the total production cost of algae bio-fuel conversion. The production cost of algae bio-fuel has still higher than that of the other commercial bio-fuel. The reduction of production cost for each process enables the competitive price as a bio-fuel. It is difficult to separate the algae from water because of the similar magnitude of density each other. The agglomeration and extracting of algae using ultrasonic wave is rare effect of environmental hazard and also it is appropriate technology for the next generation energy resources. The present research is investigated for the elucidation of algae behavior in the water with the ultrasonics wave. For this purpose, the unsteady computational fluid dynamic analysis has been conducted in the ultrasonic pressure field. The velocity, pressure and algae concentration changes with time have been analysed to clarify the mechanism of algae separation by ultrasonic wave.