• International Journal of Naval Architecture and Ocean Engineering
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• 제12권1호
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• pp.178-183
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• 2020

A series of experiments covering lowest three natural frequencies of rolling coupled pitching were conducted to investigate liquid sloshing with low liquid depth. The test results show that the most violent liquid sloshing in rolling and pitching is located in the vicinity of the first order natural frequency (f1). When the excitation frequency of rolling and pitching is located between 0.98f1 and 1.113f1, roof-bursting phenomenon of liquid appeared, and the maximum impact pressure is at 1.09f1. When the external excitation frequency is at 1.113f1, the number of sloshing shocks decreases sharply. Furthermore, the space distribution of the impact pressure on the left bulkhead and the top bulkhead was analyzed. It is concluded that with low liquid filling, the impact load is greater near the free surface and the top of tank, and the impact position of the side bulkhead increases with the increasing of the frequency near the resonant frequency.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1996년도 춘계학술대회
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• pp.119-130
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• 1996

We review the factors which regulate the depth and composition of the human airway surface liquid (ASL). These include secretion from airway submucosal glands, ion and fluid transport across the surface epithelium, goblet cell discharge, surface tension and transepithelial gradients in osmotic and hydrostatic pressure. We describe recent experiments in which we have used low temperature scanning electron microscopy of rapidly frozen specimens to detect changes in depth of ASL in response to submucosal gland stimulation. We also present preliminary data in which X-ray microanalysis of frozen specimens has been used to determine the elemental composition of ASL.

• 한국전산구조공학회논문집
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• 제32권1호
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• pp.29-35
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• 2019

본 논문에서는 건축물 진동저감장치에 적용되는 액체감쇠기 내 유체 자유표면의 동적 거동 계측을 위해 저가형 RGB-depth 센서인 Microsoft사 $Kinect^{(R)}$ v2의 활용과 계측시스템을 구축하는 방법을 제안하였다. $Kinect^{(R)}$ v2의 성능검토 및 실효성 확인, SDK(software development kit)를 사용한 실시간 모니터링, 3D 공간상에서 유체의 표면 정보 취득, 기존 비디오 센싱기법과의 비교를 통해 본 연구에서 제안한 유체의 동적 거동 계측 시스템의 정확성과 우수성을 검증하였다. 제안된 계측시스템을 활용하여 소형 수조 내 액체에 대한 동적 거동 정밀계측을 수행하였으며, 이를 바탕으로 광범위한 가진입력에 대한 유체 자유표면의 동적 거동 특징을 확인하였다. 본 연구의 결과를 바탕으로 RGB-depth센서의 건축물 진동저감 적용을 통해 정밀한 모니터링 시스템을 구축하고 최적화된 액체감쇠기의 설계 및 운용을 기대할 수 있다.

• 한국분무공학회지
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• 제4권3호
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• pp.32-41
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• 1999

In this research, internal-mixing twin-fluid atomizer using sonic energy is designed and manufactured. We are trying to intimate high efficiency twin-fluid atomizer to obtain good liquid atomization in the low pressure region. Define of geometric form of atomizer, characteristics of spray is influenced by position, depth and height variation of cavity resonator, variation of sound intensity and resonant sound frequency with liquid flow rate. The liquid atomization is promoted by multi-stage disintegration of mixing flow of gas with liquid and the optimum condition of position and depth of cavity resonator according to sonic energy is obtained from the condition at a=2.5mm and L=2mm. The velocity distribution of droplets shows negative value due to recirculation region at the center of axial, and as the radial direction distance is far, the velocity distribution of droplets decrease slowly after having a maximum value. However velocity and SMD show nearly uniform distribution at the down stream and as result compared to Nukiyama and Tanasawa's equation. atomization of mixing flow with air and liquid dispersing from the outlet of the nozzle is promoted by the effect of collision at the cavity resonator.

• Bulletin of the Korean Chemical Society
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• 제24권1호
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• pp.99-105
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• 2003

A liquid-liquid extraction followed by evaporative concentration method was used to determine the concentration of normal, or straight chain, saturated hydrocarbons (NSH) $(C_{10}\;to\;C_{24})$ and polycyclic aromatic hydrocarbons (PAH) here defined as: fluorene, anthracene, pyrene, chrysene and perylene, in the Buriganga River water of Bangladesh. Samples were collected from 5 and 25 cm depth of water at the southern, middle and northern parts of the river at Postogolla, Sadarghat and Sowarighat stations. Hydrocarbons were extracted from 450 mL of water into 75 mL n-hexane and then concentrated into 1 or 2 mL solution by evaporation. These solutions were analyzed by gas chromatography. The highest and lowest concentrations were determined as $257\;{\mu}gL^{-1}\;for\;C_{13}\;and \;0.24\;{\mu}g\;L^{-1}\;for\;C_{22}$ at 5 ㎝ depth of water, at the northern part of the Sowarighat and southern part of the Postogolla, respectively. This method could allow the analysis of water for $C_{22}$ as low as $0.24\;{\mu}g\;L^{-1}$.

• E2M - 전기 전자와 첨단 소재
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• 제8권5호
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• pp.564-571
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• 1995

This paper deals with the arc discharge characteristics of kerosene oil as a basic study on electrical discharge machine. Using needle electrode the discharge voltage, discharge current, discharge energy and the shape of discharge crater are measured. In consequence, it becomes clear that the discharge crater(depth, height, diameter) is depending on the discharge energy. Rapid increase in depth, height and diameter of discharge crater was observed during initial discharge, where discharge energy is large. However, rather slow decrease of those values was found when discharge energy is low or N is more than 3. As the ratio of $I_p$$T_on$ increase, the shape of discharge crater gets near circle. The protuberances of the discharge crater were not formed by the melted needle electrode but by the that of work piece.

• 한국토양비료학회지
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• 제34권3호
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• pp.153-157
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• 2001

To evaluate the effect of liquid pig manure application, the growth and yield of rice and the quality of infiltration water were investigated with application of different amounts of liquid manure. At this study, liquid pig manure was treated with 100, 200, 300 and 400% of recommending nitrogen fertilizer level, respectively. Liquid manure with application rate more than 200% of recommending N fertilizer level (11kg) caused to increase of plant height and number of tiller at panicle formation stage, but it caused the plant disease and pest and plant lodging. In those treatment, number of panicles per hill and number of spikelets per panicle were increased, but yield of rice was less than chemical fertilizer treatment due to low rate of ripeness and 1,000 grain weight. $NO_3-N$ concentration in infiltration water sample collected at 90 cm of soil depth was increased with increasing application amount of liquid manure. With liquid manure application more than 200% of recommending N fertilizer level, it affected negatively on yield and environment such as groundwater quality.

• 한국해양공학회지
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• 제33권2호
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• pp.106-115
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• 2019

The interaction between a sloshing liquid damper (SLD) tank and a rectangular pontoon was investigated under the assumption of the linear potential theory. The eigenfunction expansion method was used not only for the sloshing problem in the SLD tank but also for analyzing the motion responses of a rectangular pontoon in waves. If the frictional damping due to the viscosity of the SLD tank was ignored, the effect of the SLD appeared to be an added mass in the coupled equation of motion. The installation of the SLD tank had a greater effect on the roll motion response than the sway and heave motion of the pontoon. One resonance peak for rolling motion showed up in the case of a frozen liquid in the SLD tank. However, if liquid motion in the SLD tank was allowed, two peaks appeared around the first natural frequency of the fluid in the SLD tank. In particular, the peak value located in the low-frequency region had a relatively large value, and the peak frequency located in the high-frequency region moved into the high-frequency region as the depth of the liquid in the tank increased.

• Genomics & Informatics
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• 제15권1호
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• pp.48-50
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• 2017

Tumor tissues from biopsies or surgery are major sources for the next generation sequencing (NGS) study, but these procedures are invasive and have limitation to overcome intratumor heterogeneity. Recent studies have shown that driver alterations in tumor tissues can be detected by liquid biopsy which is a less invasive technique capable of both capturing the tumor heterogeneity and overcoming the difficulty in tissue sampling. However, it is still unclear whether the driver alterations in liquid biopsy can be detected by targeted NGS and how those related to the tissue biopsy. In this study, we performed whole-exome sequencing for a breast cancer tissue and identified PTEN p.H259fs*7 frameshift mutation. In the plasma DNA (liquid biopsy) analysis by targeted NGS, the same variant initially identified in the tumor tissue was also detected with low variant allele frequency. This mutation was subsequently validated by digital polymerase chain reaction in liquid biopsy. Our result confirm that driver alterations identified in the tumor tissue were detected in liquid biopsy by targeted NGS as well, and suggest that a higher depth of sequencing coverage is needed for detection of genomic alterations in a liquid biopsy.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제34회 춘계학술대회논문집
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• pp.165-169
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• 2010

케로신과 액체산소를 사용하는 액체로켓엔진은 극저온 영역과 고온의 연소가스 영역이 공존하게 된다. 전기부품을 포함한 엔진의 각 부품의 원활한 작동을 위해서는 단열재가 적절하게 엔진에 적용되어야 한다. 본 연구에서는 이러한 액체로켓엔진의 단열재 적용방안에 대해 세단계로 나누어 고찰하였다. 첫 번째로 고온및 극저온 부품을 정의하고 영역의 온도장을 해석하는 것이다. 두 번째는 각 부품 간을 연결해주는 배관 등의 연결부품에 대한 열전달 해석을 수행한다. 세 번째로 이러한 열전달 해석을 근거로 단열기준을 설정하여 적절한 온도분포가 형성되도록 단열재를 선정하고 적용하는 것이다. 본 논문에서는 이러한 적용방안에 대한 해외사례를 고찰하고 각 단계별로 단열재 적용방안을 마련해 본다.