• Journal of the Korean Institute of Gas
• /
• v.13 no.4
• /
• pp.1-7
• /
• 2009

In recent years, the needs for more fuel-efficient and lower-emission vehicles have driven to use the alternative fuel of LPG(Liquefied Petroleum Gas) which is able to meet the more stringent legislations without many modifications to current engine. LPLi (Liquid Phase LPG Injection) system (the 3rd generation LPG injection system) is the core technology to produce power equivalent to a gasoline engine with less emissions. The LPG fuel pump can supply the compressed LP gas in the liquid phase to engine. The fuel filter is attached in the fuel pump to eliminate the remnants in the liquid phased LP gas and the performance of blowoff flow for a pump can be varied with various filters. In this study, experiments were conducted to investigate the performance and efficiency of the impeller type LPG fuel pump under various filter types of microfiber, double mesh and external filter. And blowoff flow for a LPG fuel pump was measured according to the temperature of the fuel.

• Textile Coloration and Finishing
• /
• v.8 no.3
• /
• pp.36-51
• /
• 1996

In order to investigate the degradation behavior of PET fabrics, sodium diethylene glycolate (SDEG)-diethylene glycol (DEG) solutions were prepared and PET fabrics were treated in the solution. The dissolution rate constant and apparent activation energy of the PET fabrics were calculated by Eyring's and Arrhenius's equation respectively and measured dyeing properties, moisture and antistatic properties. Then compared SDEG-treated fabrics with NaOH-treated. The results were as follows; 1. PET fabrics decreased their weight in SDEG-DEG solution, and the decreasing rate showed a linear relationship to the treating time at constant temperature and concentration of SDEG-DEG solution. 2. The dissolution rate constant showed a linear relationship to the concentration of SDEGDEG solution and an exponential relationship to treating temperature. 3. Apparent activation energy of dissolution was 23.45 kcal/mol. 4. The K/S values and the ΔL values of fabrics treated with SDEG-DEG solution are higher and lower respectively than fabrics treated with NaOH. 5. SDEG-DEG solution treatment improved fabric's moisture regain and it reached almost maximum at about 40% weight loss. 6. In the both reagent the light, wet and sublimation fastness of fabrics are similar. 7. SDEG-DEG solution gave more electrical discharge effect to the fabrics than that of NaOH. 8. NaOH treated PET microfiber have crater-like surface, while SDEG-DEG solution give bathochromic effect to the PET microfiber because which has wrinkles on the surface.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.08a
• /
• pp.277.2-277.2
• /
• 2013

Petri dishes and glass slides have been widely used as general substrates for in vitro mammalian cell cultures due to their culture viability, optical transparency, experimental convenience, and relatively low cost. Despite the aforementioned benefit, however, the flat two-dimensional substrates exhibit limited capability in terms of realistically mimicking cellular polarization, intercellular interaction, and differentiation in the non-physiological culture environment. Here, we report a protocol of culturing embryonic rat hippocampal neurons on the electro-spun polymeric network and the results from examination of neuronal cell behavior and network formation on this culture platform. A combinatorial method of laser-scanning confocal fluorescence microscopy and live-cell imaging technique was employed to track axonal outgrowth and synaptic connectivity of the neuronal cells deposited on this model culture environment. The present microfiber-based scaffold supports the prolonged viability of three-dimensionally-formed neuronal networks and their microscopic geometric parameters (i.e., microfiber diameter) strongly influence the axonal outgrowth and synaptic connection pattern. These results implies that electro-spun fiber scaffolds with fine control over surface chemistry and nano/microscopic geometry may be used as an economic and general platform for three-dimensional mammalian culture systems, particularly, neuronal lineage and other network forming cell lines.

• Korean Chemical Engineering Research
• /
• v.48 no.5
• /
• pp.545-555
• /
• 2010

Recently, droplet-based microfluidic systems are widely used in various areas ranging from fundamental science including chemistry, biology, and physics to material science and engineering. This article reviews recent development in the droplet based microfluidic system from basic fabrication of tiny device, principle of droplet formation, merging, mixing, control of droplets, and application for the synthesis of novel functional materials. We discuss strong advantages of the droplet based microfluidics in point of control of particle size, morphologies, shapes, and structures.

• Textile Coloration and Finishing
• /
• v.23 no.4
• /
• pp.304-311
• /
• 2011

For sound absorption and sound insulation in automobile industry, the sound absorption materials based on meltblown nonwovens were prepared by SMS (spunbond-meltblown-spunbond) technique. And the sound absorption coefficient (${\alpha}$) of the meltblown nonwoven, produced with isotatic-polypropylene(PP), was examined for the various processing conditions such as die-to-collector distance(DCD), nonwoven weight(GSM), and air suction conditions. The meltblown nonwoven for sound absorption materials was composed of bulky microfiber web, increasing with increases in weight and DCD. The sound absorption coefficient(${\alpha}$) was excellent as a sound absorption materials of PAD type composed of SMS(spunbond-meltblownspunbond) nonwovens.

• Journal of Fashion Business
• /
• v.20 no.6
• /
• pp.52-65
• /
• 2016

Presently, sleep disorders are rapidly increasing due to sudden social development and lifestyle diversification. Among the various factors contributing to comfortable sleep, bedclothes are a major factor that readily influence the sleeping conditions, as they directly come in contact with the human body. This study therefore researches use and purchasing status of bedclothes by consumers, as well as the subjective satisfaction. This would accordingly help us to understand the consumers' performance needs, and collect basic data to develop bedclothes that assist comfortable sleep. This study used multiple choice questions and a 5-point Likert scale in a survey-style research. The results of the study indicate that consumers prudently considered practicality and durability, as bedclothes are seldom purchased. The most preferred material was cotton, but the use of microfiber, a new material, has also increased. Further, consumers' preferred lightweight bedclothes that displayed excellent water absorption, thermal insulation, durability, detergency, and flexibility. Hence, bedclothes developed according to the results of this study are expected to aid comfortable sleep.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2004.05a
• /
• pp.18-21
• /
• 2004

This paper discusses how steel cord and PVA hybrid fibers enhance the performance of high performance fiber reinforced cementitious composites (HPRFCC) in terms of elastic limit, strain hardening response and post peak of the composites. The effect of microfiber(PVA) blending ratio is presented. For this purpose flexure, direct tension and split tension tests were conducted. It was found that HFRCC specimen shows multiple cracking in the area subjected to the greatest bending tensile stress. Uniaxial tensile test confirms the range of tensile strain capacity from 0.5 to $1.5\%$ when hybrid fiber is used. The cyclic loading test results identified a unique unloading and reloading response for this ductile composite. Cyclic loading in tension appears not to affect the tensile response of the material if the uniaxial compressive strength during loading is not exceeded.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.13 no.2
• /
• pp.21-27
• /
• 2014

Recently, various biochip environments have been presented. In this study, a novel transparent film with porous membrane windows, which is an essential component in a co-cultured biochip environment, is fabricated using spin-coating, 3D printing, and electrospinning processes. In detail, a transparent polystyrene film was fabricated by means of the spin-coating process followed bywindow cutting, after which apolycaprolactone-chloroform solution was deposited along the window edge to introduce an adhesion layer between the PS film and the PCL nanofibers. Nanofibers were electrospun into the window region using a direct-write electrospinning method. Consequently, it was demonstrated that the fabricated window film could be used in a co-culture biochip environment.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.2
• /
• pp.431-433
• /
• 2011

Alginate microfibers were fabricated by self assembly of alginate monomers exuded from alginate beads (~2 mm in diameter) containing calcium phosphate. Upon incubation of the beads in cell culture medium at $37^{\circ}C$ for a few days, fibers with a diameter of about $7{\mu}m$ started to sprout from the bead surface, and these grew up to about 10 mm in length, resulting in the beads being covered with fiber forests similar to chestnut bur. The combined system of the alginatebased microfiber forest and bead is considered to be useful as a novel 3-dimensional scaffold for cell culture and tisssue growth.

• Proceedings of the KIEE Conference
• /
• 2015.07a
• /
• pp.1225-1226
• /
• 2015

본 연구에서는, carbon microfiber (CMF) 소재를 이용하여 전극을 제작하고 이를 바탕으로 플렉시블 비대칭 슈퍼커패시터를 설계 및 제작하여 특성을 측정 및 분석하였다. 제작된 CMF 전극은 넓은 비표면적과 물리적 안정성 및 화학적 안정성, 높은 유연성을 가지며 무게가 가벼운 특징을 가진다. 개발된 슈퍼커패시터의 양극과 음극은 각각 CMF/Cu/NiO과 단일 CMF로 구성되어져 있으며, KOH 전해질 수용액에서 우수한 슈도 커패시터의 우수한 동작 특성을 나타내었으며, 슈퍼커패시터의 특성 커패시턴스와 평균 에너지 밀도는 각각 22.1 F/g와 8.9 Wh/kg을 나타내었다.