• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.8
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• pp.1009-1023
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• 1997

The breakup length of a liquid jet with flowrate, formed by releasing through a nozzle of circular cross-section into the atmosphere, was experimented and studied for 3 liquid nozzles of varying diameters. The experimental result was analyzed using the existing theoretical equation for predicting the breakup length. It was found that the breakup length of liquid jet depends on the velocity, and the breakup length increases with increasing of the liquid nozzle diameter. Also, the variation range of the breakup length for the same flowrate of liquid increased rapidly as velocity was increased for laminar flow, but in the turbulent flow region, it leveled off in the range of approximately 0.55-0.7 of the mean breakup length. Furthermore, when the longest smooth liquid jet was applied to the co-axial flow air blast atomizer, the effect of air flow on the flow pattern and breakup length was studied for 6 glass nozzles of different lengths and diameters. It was found that depending on the diameter of the mixing tube and liquid jet, it was possible to observe a wide range of flow patterns, such as liquid jet through flow, partial annular flow and annular flow. The liquid jet breakup length was more sensitive to the change in the length rather than the diameter of the mixing tube. As the length of the mixing tube shortens, the breakup length also shortens rapidly.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.2
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• pp.166-174
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• 2009

The liquid column trajectory and column breakup length characteristics have been experimentally studied in angled jets injected into subsonic crossflow. Pulsed shadowgraph photography and Planar Liquid Laser Induced Fluorescence measurements were used to determine the angled effects. And the main objectives of this research are to get a empirical formula of liquid column trajectory and breakup length with below the $90^{\circ}$ degree injection angle conditions, and were compared with previous results. It was also found that the empirical formula, which reversed injection conditions of air stream. As the result, This has been shown that liquid column trajectories and column breakup length were spatially dependent on various injection angle, normalized injector exit diameter, air-stream and fuel injection velocity. Furthermore, the empirical formula of liquid column trajectories and breakup length has been some different of drag coefficient results between normal angled injection and reversed injection in subsonic crossflow.

• Environmental Analysis Health and Toxicology
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• v.18 no.3
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• pp.225-230
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• 2003

본 연구는 DNA 상해유도기작을 규명하기 위하여 하등 진핵생물인 분열형 효모 Schizosaccharomyces Pombe로부터 subtraction hybridization방법을 이용하여 자외선 유도 유전자인 UVI-180을 분리하고 그 유전자 구조와 발현양상을 조사하였다. UVI-180유전자의 발현양상을 Northern hybridization 방법으로 살펴본 결과 자외선(ultraviolet-light)조사 1시간 후에 최대의 발현 증가를 나타내었다. 반면 알킬화제인 MMS(methyl methanesulfonate)처리에 의해서는 전혀 발현이 증가되지 않았다. 이 결과 UVI-180유전자는 DNA상해에 따라 각기 다른 발현양상을 나타냄을 알 수 있었다. 유전자의 기능을 알기 위하여 null-mutant세포 주를 제조하여 그 특성을 살펴본 결과 이 유전자는 세포의 성장에 필수적인 유전자임을 알 수 있었다.

• Journal of ILASS-Korea
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• v.4 no.4
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• pp.30-37
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• 1999

The breakup characteristics of liquid sheet formed by the liquid rocket injector has a close relation with the combustion efficiency. In this paper, basic characteristics of droplet size and velocity distribution were measured with PDPA for the Like Doublet Impinging Injector. Test variables were the angle of impact, the diameter of orifice and jet velocity. Water was used as test fluid. As a result, for impingement angle less than 90 degree, following correlations were obtained between drop size and design parameters : $D_{32}({\mu}m)=295.0{\times}V^{-0.09}\times(2\theta)^{-0.1}{\times}d^{0.072}$. For impingement angle greater than 100 degree, drop sizes were increased but eventually converged to a certain limiting value.

• Korean Journal of Psychosomatic Medicine
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• v.13 no.1
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• pp.32-40
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• 2005

Objectives : This study looked at the symptoms of alexithymia in schizophrenia and their association with clinical variables and schizophrenic symptomatology. Methods Consecutive fifty eight inpatients with DSM-IV diagnoses of schizophrenia completed 26item version of Toronto Alexithymia Scale (TAS), Symptom Checklist-90-Revised(SCL-90-R), and Positive and Negative Syndrome Scale(PANSS). Results : Authors did not find any correlation between scores of PANSS and TAS. However, all the subscale scores of SCL-90-R were significantly correlated with total score of TAS. Also, 'difficulty identifying and deistinguishing between feelings and bodily sensations' and 'difficulty describing feelings' significantly correlated with SCL-90-R subscale scores. 'Reduced daydreaming' had mixed findings and 'externally oriented thinking' did not correlate. Multiple regression model included Global Severity Index of SCL-90-R accounting 28.2% of variance for TAS scores. Conclusion : These findings together with discrepancy in results between objective and subjective tests suggest that alexithymia in schizophrenia may have two constructs, 'difficulty to describe and communicate feelings(state)' and 'externally oriented thinking(trait)' Authors suggest further study needs to confirm construct validity of TAS in this population.

• The Korean Journal of Mycology
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• v.26 no.2 s.85
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• pp.187-193
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• 1998

The effects of medium, incubation temperature, incubation period, pH of medium and $CO_2$ ondition during mycelial growth were investigated to study the factors associated with the formation of oidia in Flammulina velutipes. Oidia formation was increased when mycelial growth was poor, while oidia formation was inhibited in optimum condition of mycelial growth. Mating type of oidia was investigated to examine the effect of oidia formation on dikaryotic strain. Di-mon matings between oidia strains and original dikaryotic strain were carried out. Monokaryotic strains derived from oidia showed only one genotype. Seventy percent among Dimon mating strains showed slow mycelial growth and low yield of fruit-body, but others showed similar or high mycelial growth and yields in comparision with original dikaryon strain. One strain from di-mon mating demonstrated some differences in isozyme band pattern.

• Journal of the Korean Society of Propulsion Engineers
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• v.10 no.3
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• pp.1-8
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• 2006

The influences of injection conditions and recess configuration of liquid-liquid swirl coaxial injectors on spray characteristics were investigated. The characteristics of the coaxial spray in internal mixing injection region were mainly controlled by the merging phenomenon and momentum balance between two liquid sheets, but those in internal mixing injection region were influenced by the impingement phenomenon as well as momentum balance between two liquid sheets.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.12
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• pp.48-58
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• 2006

The spray and combustion characteristics of liquid jet in cross flow with variation of injection angle are numerically studied. Numerical analysis was carried out using KIVA code, which may be used to generate numerical solutions to spray and chemical reactive fluid problem in three space dimensions and modified to be suitable for simulating liquid jet ejected into the cross flow. Wave model and Kelvin- Helmholtz(KH) /Rayleigh-Taylor(RT) hybrid model were used for the purpose of analyzing liquid column, ligament, and the breakup of droplet. Penetration length increases as flow velocity decreases and injection velocity increases. Numerical error increases as inflow velocity increases. The results of flame propagation contour in combustion chamber and local temperature distribution, combustion emissions were obtained.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.05a
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• pp.147-150
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• 2006

The influences of injection conditions and recess configuration of liquid-liquid swirl coaxial injector on spray characteristics were investigated. The characteristics of the coaxial spray in internal mixing injection region were mai y controlled by the merging phenomenon and momentum balance between two liquid sheets, but those in internal mixing injection region were influenced by the impingement phenomenon as well as momentum balance between two liquid sheets.

• Applied Biological Chemistry
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• v.30 no.4
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• pp.300-304
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• 1987

Effects of benzyladenine (BA) on viability, cell wall regeneration and division of soybean (Glycine max, Var. Acme) protoplasts isolated from suspension cells of cotyledonary callus were investigated. The uptake of BA by the protoplasts was also studied. BA increased protoplast viability, and promoted cell wall regeneration and cell division. The level of BA in protoplasts was increased to a maximum at about 20 hour incubation and 2/3 of the total amount of BA accumulated in protoplast was absorbed within 6 hours.