• Fashion & Textile Research Journal
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• v.16 no.3
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• pp.446-455
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• 2014

This study revealed the results related to the functionality of outdoor wear required when man and women in their 30s to 50s engage in outdoor activities. Based on the results of the survey, we proposed composition draft for a smart outdoor jacket with main functions of GPS device and light-emitting device using solar cell and EL. Absorption and release of sweat, functionality regarding rain and wind, and lightweightness, etc. from material functionalities of outdoor wear were found to be important. From function required in clothing for outdoor activity, location tracking, night glow, and lighting functions were found to be most important. For results investigating the necessity of the jacket's location tracking function and lighting function using solar cell, high scores of 3.9~4.0 were given. Purchase intentions for smart outdoor jacket with location tracking and lighting functions devised by this study were fairly positive and most responses indicated that the appropriate purchase price was between 200,000 to 300,000 won while possible problems of this smart outdoor jacket were listed in the order of washing inconvenience, high price, device weight, and discomfort in movement. The draft proposal to integrate with wearable devices for smart outdoor jacket prototype is as follows: Solar cell has been attached to the upper arm but placed inside a transparent pocket which has been detachable for washing convenience while the solar cell and controller have been integrated into a single unit. Using frequent movement exhibited by the arms, EL has been attached along the center line of the raglan sleeve for easy spotting when used as an emergency signal or for night lighting function during outdoor activity. GPS has been attached on the left sleeve so that the person can bend the left arm inward and operate the GPS screen with the right hand while walking or running outdoors.

• International Journal of Oral Biology
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• v.33 no.4
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• pp.125-129
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• 2008

Inositol 1,4,5-trisphosphate ($IP_3$) plays an important role in the release of $Ca^{2+}$ from intracellular stores into the cytoplasm in a variety of cell types. $IP_3$ translocation dynamics have been studied in response to many types of cell signals. However, the dynamics of cytosolic $IP_3$ in salivary acinar cells are unclear. A green fluorescent protein (GFP)-tagged pleckstrin homology domain (PHD) was constructed and introduced into a phospholipase C ${\delta}1$ (PLC ${\delta}1$) transgenic mouse, and then the salivary acinar cells were isolated. GFP-PHD was heterogeneously localized at the plasma membrane and intracellular organelles in submandibular gland and parotid gland cells. Application of trypsin, a G protein-coupled receptor activator, to the two types of cells caused an increase in GFP fluorescence in the cell cytoplasm. The observed time course of trypsin-evoked $IP_3$ movement in acinar cells was independent of cell polarity, and the fluorescent label showed an immediate increase throughout the cells. These results suggest that GFP-PHD in many tissues of transgenic mice, including non-cultured primary cells, can be used as a model for examination of $IP_3$ intracellular dynamics.

• International Journal of Stem Cells
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• v.16 no.2
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• pp.202-214
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• 2023

Background and Objectives: To investigate the role of exosomes from periodontal ligament cells (PDLCs) in bone marrow mesenchymal stem cell (BMSC) migration. Methods and Results: Human PDLCs were applied cyclic tension stretching. Exosomes were extracted from cultured PDLCs by ultracentrifugation, then characterized for their size, morphology and protein markers by NTA, TEM and western blotting. The process that PKH26-labeled exosomes taken up by BMSCs was assessed by confocal microscope. BMSC migration was examined by Transwell assay. Exosomes derived from PDLCs were identified. Cyclic tension stretch application on PDLCs can enhance the migration ability of BMSCs through exosomes. The exosomal miRNA expression profiles of unstretched and stretched PDLCs were tested by miRNA microarray. Four miRNAs (miR-4633-5p, miR-30c-5p, miR-371a-3p and let-7b-3p) were upregulated and six (miR-4689, miR-8485, miR-4655-3p, miR-4672, miR-3180-5p and miR-4476) were downregulated in the exosomes after stretching. Sixteen hub proteins were found in the miRNA-mRNA network. Gene Ontology and KEGG pathway analyses demonstrated that the target genes of differentially expressed exosomal miRNAs closely related to the PI3K pathway and vesicle transmission. Conclusions: The exosomes derived from cyclic tension-stretched PDLCs can promote the migration of BMSCs. Alternation of microRNA profiles provides a basis for further research on the regulatory function of the exosomal miRNAs of PDLCs during orthodontic tooth movement.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.10a
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• pp.593-602
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• 2006

대구경 현장타설말뚝에 대한 시험하중의 증가와 함께 적용이 활성화되고 있는 오스터버그 셀(Osterberg cell)방식이 적용된 국외의 4 개소 시험결과에 대하여 소개하였다. 사례연구의 대상이 된 4 개소 시험말뚝은 일반적인 시험보다는 결과상의 특징이 있어 현재 및 향후 동일한 시험방법이 적용될 경우 고려될 수 있는 내용을 중심으로 기술하였다. 이들 말뚝시험에서는 가장 전형적으로 지지력의 균형이 이루어져 말뚝의 극한현상이 발생되지 않아 설계하중을 충분히 확인한 경우뿐 아니라 선단지지력이 부족하여 선단 그라우팅 후 재시험을 한 경우, O-cell을 말뚝의 선단에 가장 근접하여 설치 한 후 시험한 경우, 그리고 다단면(multi-level test)시험이 수행되었던 예 등을 살펴보았다.

• Journal of Sensor Science and Technology
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• v.17 no.4
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• pp.245-249
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• 2008

This paper presents a microfluidic cell sizing method using hydrophoretic size-based separation. By exploiting slanted obstacles in a microchannel, we can generate a lateral pressure gradient so that microparticles can be deflected and arranged along lateral flows induced by the gradient. Using such movement of particles, we discriminated 8 to 15 μm-sized beads. We measured the size of U937 cells by comparing the hydrophoretic response of the cells to those of the size-standard beads whose diameters are known. Due to its simple design and fabrication, the sizing method can be easily integrated with other microfluidic components such as cell culture chambers conducting on-chip sizing and sorting.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.13 no.2
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• pp.123-140
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• 2009

The effect of a solute concentration difference on the osmotic transport of water through the semi-permeable membrane of a simple cell model is investigated. So far, most studies on osmotic phenomena are described by simple diffusion-type equations ignoring all fluid motion or described by Stokes flow. In our work, as the governing equations, we consider the coupled full Navier-Stokes equations which describe the fluid motion and the full transport equation that takes into account of convection and diffusion effects. A two dimensional finite difference model has been developed to simulate the velocity field, concentration field, and semi-permeable membrane movement. It is shown that the cell swells to regions of lower solute concentration due to the uneven water flux through the semi-permeable membrane. The simulation is applied on a red blood cell geometry and the relevant results are presented.

• Nuclear Engineering and Technology
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• v.38 no.5
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• pp.449-454
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• 2006

Neutron imaging technique was used to investigate the water distribution and movement in Polymer Electrolyte Membrane Fuel Cell (PEMFC) at HANARO, KAERI. The Feasibility tests were performed in the first and second exposure rooms at the neutron radiography facility (NRF) at HANARO in order to check the ability of each exposure room, respectively. The feasibility test apparatus was composed of water and pressurized air before making up the actual test apparatus. Due to the low neutron intensity in the second exposure room, the exposure time was too long to investigate the transient phenomena of PEMFC. Although the exposure time was improved to 0.1 sec in the first exposure room, it was difficult to discriminate detail water movement at the channel due to the high noise level. Therefore, the experimental setup must be optimized according to the test conditions. Water discharge characteristics were investigated under different flow field geometries by using feasibility test apparatus and the neutron imaging technique. The water discharge characteristics of a 3-parallel serpentine are superior to those of a 1-parallel serpentine, but water at Membrane Electrode Assembly (MEA) was not removed, regardless of the flow field type.

• Journal of Electrochemical Science and Technology
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• v.10 no.2
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• pp.104-114
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• 2019

Energy is an essential driving force for modern society. In particular, electricity has become the standard source of power for almost every aspect of life. Electric power runs lights, televisions, cell phones, laptops, etc. However, it has become apparent that the current methods of producing this most valuable commodity combustion of fossil fuels are of limited supply and has become detrimental for the Earth's environment. It is also self-evident, given the fact that these resources are non-renewable, that these sources of energy will eventually run out. One of the most promising alternatives to the burning of fossil fuel in the production of electric power is the proton exchange membrane (PEM) fuel cell. The PEM fuel cell is environmentally friendly and achieves much higher efficiencies than a combustion engine. Water management is an important issue of PEM fuel cell operation. Water is the product of the electrochemical reactions inside fuel cell. If liquid water accumulation becomes excessive in a fuel cell, water columns will clog the gas flow channel. This condition is referred to as flooding. A number of researchers have examined the water removal methods in order to improve the performance. In this paper, a new water removal method that investigates the use of vibro-acoustic methods is presented. Piezo-actuators are devices to generate the flexural wave and are attached at end of a cathode bipolar plate. The "flexural wave" is used to impart energy to resting droplets and thus cause movement of the droplets in the direction of the traveling wave.

• The Korean Journal of Physiology
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• v.1 no.2
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• pp.151-156
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• 1967

Outward movement of hemoglobin and $K^+$ ion across rabbit erythrocyte membrane after heating, cooling and in acid medium was studied. One milliliter of rabbit blood was centrifuged and packed red cells were obtained. Packed red cells were resuspended by addition of 4 ml of 0.9% NaCl solution and were subjected to heating $(57^{\circ}C\;for\;5\;minutes)$ or cooling $(-4^{\circ}C{\sim}-8^{\circ}C\;of\;-10^{\circ}C{\sim}-11^{\circ}C\;for\;10\;minutes) $. For acid medium experiment packed ref cells were resuspended by addition of 4 ml of acid medium of PH 4.5 consisting of 0.01% glacial acetic acid in 0.85% NaCl solution and kept standing for 10 minutes. All red cell suspensions were centrifuged again and packed red cells were separated. This packed red cells were again suspended in 4 ml of NaCl solution of 0.8%, 0.7%, 0.6%, and 0.5% concentration respectively and kept standing for 20 minutes. The concentration of hemoglobin and $K^+$ in the supernatant of the above red cell suspensions were measured and the following results were obtained. 1. Outward movement of hemoglobin and $K^+$ was greatest in red cells subjected to heating. The movement paralled to the osmolal concentration gradient between extra- and intra-cellular phase of red cells. 2. In acid medium the outflux of hemoglobin and $K^+$ increased as compared to the control. 3. In red cells subjected to the cold of $-10^{\circ}C{\sim}-11^{\circ}C$ the outflux of hemoglobin and $K^+$ increased. Whereas in the environment of $-4^{\circ}C{\sim}-8^{\circ}C$ there was no change in the outflux of $K^+$. The he-moglobin outflux showed rather a decreased as compared to tile control.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.129.1-129.1
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• 2010

Since the commencement of the fuel cell business in 2007, POSCO POWER has been the major supplier of the MCFC (Molten Carbonate Fuel Cell), which is the most commercialized stationary fuel cell system in the world. With its quite, yet active movement, more than 20MW MCFC systems have been installed and are operating in Korea. While trying to localize the components and set up a firm supply chain in Korea to provide more reliable and cost-competitive products to its customers, POSCO POWER is also devoting itself to developing new MCFC application products. One such product is a back-up power system, in which a back-up algorithm is embedded to the present system so that the product can work as a back-up generator in case of grid failure. The technology to enhance load following capability of a stack module is also being developed with the back-up algorithm. Another example is a building application, the goal being to make the present Sub-MW product suitable for urban area. For this, downsizing and modularization are the main R&D scope. The project for developing ship service fuel cell for APU application will launch soon as well. In the project, a system which can operate in marine environment, and reforming technology for liquid logistic fuel will be developed.