• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2007년도 춘계학술대회B
• /
• pp.3329-3334
• /
• 2007

The purpose of the research is to investigate of diesel spray combustion for simultaneously reduce way NOx and PM. The pressure diesel injection were done into intermediates that are generated by very lean DME HCCI combustion using a RCM. The concentration of intermediate could not be directly measured; we estimated it by CHEMKIN calculation. DME HCCI characteristic is surveyed. Validations of the CHEMKIN calculation were confirmed pressure rise of an experiment and pressure rise of a calculation. Using a framing streak camera captured two dimensional spontaneous luminescence images from chemical species at low temperature reaction(LTR) and high temperature reaction (HTR). Also, the combustion events were observed by high-speed direct photography, the ignition and combustion were analyzed by the combustion chamber pressure profiles.

• Biomolecules & Therapeutics
• /
• 제21권2호
• /
• pp.89-96
• /
• 2013

Atherosclerotic vascular dysfunction is a chronic inflammatory process that spreads from the fatty streak and foam cells through lesion progression. Therefore, its early diagnosis and prevention is unfeasible. Reactive oxygen species (ROS) play important roles in the pathogenesis of atherosclerotic vascular disease. Intracellular redox status is tightly regulated by oxidant and antioxidant systems. Imbalance in these systems causes oxidative or reductive stress which triggers cellular damage or aberrant signaling, and leads to dysregulation. Paradoxically, large clinical trials have shown that non-specific ROS scavenging by antioxidant vitamins is ineffective or sometimes harmful. ROS production can be locally regulated by cellular antioxidant enzymes, such as superoxide dismutases, catalase, glutathione peroxidases and peroxiredoxins. Therapeutic approach targeting these antioxidant enzymes might prove beneficial for prevention of ROS-related atherosclerotic vascular disease. Conversely, the development of specific antioxidant enzyme-mimetics could contribute to the clinical effectiveness.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
• /
• pp.1302-1305
• /
• 1997

A new approach to the three-dimensional measurement of the object surface and moving particles is introduced. A single TV camera with an apparatus to add the circular bias to the image enables us to record the three-dimensional information of measuring points as streaks on a single image. Every shaped of the streak on the image plane is related to the position of the measuring point. the information is extracted form the image using an image processign technique.

• 오토저널
• /
• 제14권6호
• /
• pp.81-90
• /
• 1992

This paper deals with an experimental study on the initial condition of liquid film surface waves disintegration and investigation on the behavior of liquid film surface waves formed by the high speed air flow on the solid plane surface. The authors conducted the qualitative and quantitative study to in vestigate the liquid film flow phenomena, the liquid film disintegration mechanism, and droplet formation process with breaking the liquid film surface wave. The newly devised transparent rectangular test section which has semi-two-dimensional flow at the center of the bottom was introduced to perform the experimental study, and it can generate the uniform thickness liquid film at the bottom. The strobo streak camera was used to obtain the instantaneously transformed photographs. The electronic measuring device was also used to measure the liquid film thickness variation in order to perform the easy and effective analysis of complex flow phenomena in the air-water cocurrent flow.

• Asian-Australasian Journal of Animal Sciences
• /
• 제7권4호
• /
• pp.459-466
• /
• 1994

Primordial germ cells (PGCs) in aves are the progenitor cells for the gametes. These cells first appear in the epiblast (Eyal-Giladi et al.. 1981). Then translocate and concentrate to endoderm of germinal crescent area in the junction of the area opaca and area pellucida lateral to the primitive streak in stage 4 through 7. They separate from the endoderm, temporarily circulate via the blood vascular system, leave the blood vessels, and finally settle down in the gonadal anlagen at stage 20-24 where they rapidly proliferate to form germ cells. Recently, several attempts have been made to introduce foreign gene into the avian genome to form a transgenic chicken. The stem cells most readily available as vehicles for genetic manipulation of germline in avian species are the PGCs. PGCs have recently been manipulated genetically and used successfully as a vector for gene transfer.

• 대한기계학회논문집
• /
• 제17권2호
• /
• pp.426-437
• /
• 1993

The flowfield of Weis-Fogh type ship's Propulsion is visualized by numerical simulations using the discrete vortex method and by the hydrogen bubble technique. The simulations are performed by assuming that the separations occur at the trailing edge of the wing. The streak lines and time lines are calculated by introducing the tracers at adequate intervals. They agree well with experimental results. The flowfield is unsteady and complex, but the properties of the flow are clarified by numerical and experimental visualization.

• Journal of Mechanical Science and Technology
• /
• 제15권12호
• /
• pp.1853-1859
• /
• 2001

An experimental study is presented for a flow field in a two dimensional wavy channels by PIV. This flow has two major applications such as a blood flow simulation and the enhancement of heat transfer in a heat exchanger. While the numerical flow visualization results have been limited to the fully developed cases, existing experimental results of this flow were simple qualitative ones by smoke or dye streak test. Therefore, the main purpose of this study is to produce quantitative flow data for fully developed and developing flow regimes by the Correlation Based Correction PIV (CBC PIV) and to conjecture the analogy between flow characteristics and heat transfer enhancement with low pumping power. Another purpose of this paper is to examine the onset position of the transition and the global mixing, which results in transfer enhancement. PIV results on the Fully developed and developing flow in a wavy channel at Re=500, 1000 and 2000 are obtained. for the case Reynolds Number equals 500, the PIV results are compared with the finite difference numerical solution.

• 한국마린엔지니어링학회:학술대회논문집
• /
• 한국마린엔지니어링학회 2006년도 전기학술대회논문집
• /
• pp.291-292
• /
• 2006

This experimental study investigates the wake flow behind the flow characteristics around staggered tube arrays. In this experiment, the principal aim is to investigate the transition mechanism of the large vortex generating process in the wake having unique vortex shedding pattern. The detailed visualization is carried out using the PIV measurement. The transition mechanism of the large generating vortex is clarified by showing the streak lines. the vorticity and the statistical fluctuating velocity distributions.

• The Plant Pathology Journal
• /
• 제26권3호
• /
• pp.271-272
• /
• 2010

Burkholderia glumae causes bacterial rice grain rot and bacterial wilt on many field crops. We developed a simple diagnostic streak method for the isolation of B. glumae from diseased plant material. The geographical distribution of 178 Korean isolates shows that B. glumae is widely spread in South Korea.

• 설비공학논문집
• /
• 제16권4호
• /
• pp.368-373
• /
• 2004

A flow field in a passage with periodically converging-diverging cross-section is investigated experimentally by PIV measurement. A tube with a sinusoidally wavy cross section is one of several devices employed for enhancing the heat and mass transfer efficiency due to turbulence promotion and unsteady vortical motion. While the numerical flow visualization results have been limited to the fully developed cases, existing experimental results of this flow were simple qualitative ones by smoke or dye streak test. Therefore, the main purpose of this study is to produce quantitative flow data for fully developed and transient flow regime by the Correlation Based Correction PIV (CBC PIV) and to conjecture the analogy between flow characteristics and heat transfer enhancement with low pumping power. Another purpose of this paper is to examine the onset position of the transition and the global mixing, which results in transfer enhancement. At Re=2000, evidences of the global mixing are captured at 2.5 wavy module through the variation of RMS values and instantaneous velocity plot.